    {-# LANGUAGE CPP                 #-}
    {-# LANGUAGE DataKinds           #-}
    {-# LANGUAGE FlexibleContexts    #-}
    {-# LANGUAGE RankNTypes          #-}
    {-# LANGUAGE ScopedTypeVariables #-}
    {-# LANGUAGE TypeFamilies        #-}
    {-# LANGUAGE ViewPatterns        #-}

    {-# OPTIONS_GHC -Wno-incomplete-uni-patterns #-}

    {-
    (c) The University of Glasgow 2006
    (c) The GRASP/AQUA Project, Glasgow University, 1992-1998

    -}

    -- | Typechecking user-specified @MonoTypes@
    module GHC.Tc.Gen.HsType (
            -- Type signatures
            kcClassSigType, tcClassSigType,
            tcHsSigType, tcHsSigWcType,
            tcHsPartialSigType,
            tcStandaloneKindSig,
            funsSigCtxt, addSigCtxt, pprSigCtxt,

            tcHsClsInstType,
            tcHsDeriv, tcDerivStrategy,
            tcHsTypeApp,
            UserTypeCtxt(..),
            bindImplicitTKBndrs_Tv, bindImplicitTKBndrs_Skol,
                bindImplicitTKBndrs_Q_Tv, bindImplicitTKBndrs_Q_Skol,
            bindExplicitTKBndrs_Tv, bindExplicitTKBndrs_Skol,
                bindExplicitTKBndrs_Q_Tv, bindExplicitTKBndrs_Q_Skol,

            bindOuterFamEqnTKBndrs, bindOuterFamEqnTKBndrs_Q_Tv,
            tcOuterTKBndrs, scopedSortOuter,
            bindOuterSigTKBndrs_Tv,
            tcExplicitTKBndrs,
            bindNamedWildCardBinders,

            -- Type checking type and class decls, and instances thereof
            bindTyClTyVars, tcFamTyPats,
            etaExpandAlgTyCon, tcbVisibilities,

              -- tyvars
            zonkAndScopedSort,

            -- Kind-checking types
            -- No kind generalisation, no checkValidType
            InitialKindStrategy(..),
            SAKS_or_CUSK(..),
            ContextKind(..),
            kcDeclHeader,
            tcHsLiftedType,   tcHsOpenType,
            tcHsLiftedTypeNC, tcHsOpenTypeNC,
            tcInferLHsType, tcInferLHsTypeKind, tcInferLHsTypeUnsaturated,
            tcCheckLHsType,
            tcHsContext, tcLHsPredType,

            kindGeneralizeAll, kindGeneralizeSome, kindGeneralizeNone,

            -- Sort-checking kinds
            tcLHsKindSig, checkDataKindSig, DataSort(..),
            checkClassKindSig,

            -- Multiplicity
            tcMult,

            -- Pattern type signatures
            tcHsPatSigType,
            HoleMode(..),

            -- Error messages
            funAppCtxt, addTyConFlavCtxt
       ) where

    #include "HsVersions.h"

    import GHC.Prelude

    import GHC.Hs
    import GHC.Rename.Utils
    import GHC.Tc.Utils.Monad
    import GHC.Tc.Types.Origin
    import GHC.Core.Predicate
    import GHC.Tc.Types.Constraint
    import GHC.Tc.Utils.Env
    import GHC.Tc.Utils.TcMType
    import GHC.Tc.Validity
    import GHC.Tc.Utils.Unify
    import GHC.IfaceToCore
    import GHC.Tc.Solver
    import GHC.Tc.Utils.Zonk
    import GHC.Core.TyCo.Rep
    import GHC.Core.TyCo.Ppr
    import GHC.Tc.Utils.TcType
    import GHC.Tc.Utils.Instantiate ( tcInstInvisibleTyBinders, tcInstInvisibleTyBindersN,
                                      tcInstInvisibleTyBinder )
    import GHC.Core.Type
    import GHC.Builtin.Types.Prim
    import GHC.Types.Name.Env
    import GHC.Types.Name.Reader( lookupLocalRdrOcc )
    import GHC.Types.Var
    import GHC.Types.Var.Set
    import GHC.Core.TyCon
    import GHC.Core.ConLike
    import GHC.Core.DataCon
    import GHC.Core.Class
    import GHC.Types.Name
    -- import GHC.Types.Name.Set
    import GHC.Types.Var.Env
    import GHC.Builtin.Types
    import GHC.Types.Basic
    import GHC.Types.SrcLoc
    import GHC.Types.Unique
    import GHC.Types.Unique.FM
    import GHC.Types.Unique.Set
    import GHC.Utils.Misc
    import GHC.Types.Unique.Supply
    import GHC.Utils.Outputable
    import GHC.Utils.Panic
    import GHC.Data.FastString
    import GHC.Builtin.Names hiding ( wildCardName )
    import GHC.Driver.Session
    import qualified GHC.LanguageExtensions as LangExt

    import GHC.Data.Maybe
    import GHC.Data.Bag( unitBag )
    import Data.List ( find )
    import Control.Monad

    {-
            ----------------------------
                    General notes
            ----------------------------

    Unlike with expressions, type-checking types both does some checking and
    desugars at the same time. This is necessary because we often want to perform
    equality checks on the types right away, and it would be incredibly painful
    to do this on un-desugared types. Luckily, desugared types are close enough
    to HsTypes to make the error messages sane.

    During type-checking, we perform as little validity checking as possible.
    Generally, after type-checking, you will want to do validity checking, say
    with GHC.Tc.Validity.checkValidType.

    Validity checking
    ~~~~~~~~~~~~~~~~~
    Some of the validity check could in principle be done by the kind checker,
    but not all:

    - During desugaring, we normalise by expanding type synonyms.  Only
      after this step can we check things like type-synonym saturation
      e.g.  type T k = k Int
            type S a = a
      Then (T S) is ok, because T is saturated; (T S) expands to (S Int);
      and then S is saturated.  This is a GHC extension.

    - Similarly, also a GHC extension, we look through synonyms before complaining
      about the form of a class or instance declaration

    - Ambiguity checks involve functional dependencies

    Also, in a mutually recursive group of types, we can't look at the TyCon until we've
    finished building the loop.  So to keep things simple, we postpone most validity
    checking until step (3).

    %************************************************************************
    %*                                                                      *
                  Check types AND do validity checking
    *                                                                      *
    ************************************************************************

    Note [Keeping implicitly quantified variables in order]
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    When the user implicitly quantifies over variables (say, in a type
    signature), we need to come up with some ordering on these variables.
    This is done by bumping the TcLevel, bringing the tyvars into scope,
    and then type-checking the thing_inside. The constraints are all
    wrapped in an implication, which is then solved. Finally, we can
    zonk all the binders and then order them with scopedSort.

    It's critical to solve before zonking and ordering in order to uncover
    any unifications. You might worry that this eager solving could cause
    trouble elsewhere. I don't think it will. Because it will solve only
    in an increased TcLevel, it can't unify anything that was mentioned
    elsewhere. Additionally, we require that the order of implicitly
    quantified variables is manifest by the scope of these variables, so
    we're not going to learn more information later that will help order
    these variables.

    Note [Recipe for checking a signature]
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    Kind-checking a user-written signature requires several steps:

     0. Bump the TcLevel
     1.   Bind any lexically-scoped type variables.
     2.   Generate constraints.
     3. Solve constraints.
     4. Sort any implicitly-bound variables into dependency order
     5. Promote tyvars and/or kind-generalize.
     6. Zonk.
     7. Check validity.

    Very similar steps also apply when kind-checking a type or class
    declaration.

    The general pattern looks something like this.  (But NB every
    specific instance varies in one way or another!)

        do { (tclvl, wanted, (spec_tkvs, ty))
                  <- pushLevelAndSolveEqualitiesX "tc_top_lhs_type" $
                     bindImplicitTKBndrs_Skol sig_vars              $
                     <kind-check the type>

           ; spec_tkvs <- zonkAndScopedSort spec_tkvs

           ; reportUnsolvedEqualities skol_info spec_tkvs tclvl wanted

           ; let ty1 = mkSpecForAllTys spec_tkvs ty
           ; kvs <- kindGeneralizeAll ty1

           ; final_ty <- zonkTcTypeToType (mkInfForAllTys kvs ty1)

           ; checkValidType final_ty

    This pattern is repeated many times in GHC.Tc.Gen.HsType,
    GHC.Tc.Gen.Sig, and GHC.Tc.TyCl, with variations.  In more detail:

    * pushLevelAndSolveEqualitiesX (Step 0, step 3) bumps the TcLevel,
      calls the thing inside to generate constraints, solves those
      constraints as much as possible, returning the residual unsolved
      constraints in 'wanted'.

    * bindImplicitTKBndrs_Skol (Step 1) binds the user-specified type
      variables E.g.  when kind-checking f :: forall a. F a -> a we must
      bring 'a' into scope before kind-checking (F a -> a)

    * zonkAndScopedSort (Step 4) puts those user-specified variables in
      the dependency order.  (For "implicit" variables the order is no
      user-specified.  E.g.  forall (a::k1) (b::k2). blah k1 and k2 are
      implicitly brought into scope.

    * reportUnsolvedEqualities (Step 3 continued) reports any unsolved
      equalities, carefully wrapping them in an implication that binds the
      skolems.  We can't do that in pushLevelAndSolveEqualitiesX because
      that function doesn't have access to the skolems.

    * kindGeneralize (Step 5). See Note [Kind generalisation]

    * The final zonkTcTypeToType must happen after promoting/generalizing,
      because promoting and generalizing fill in metavariables.

    Doing Step 3 (constraint solving) eagerly (rather than building an
    implication constraint and solving later) is necessary for several
    reasons:

    * Exactly as for Solver.simplifyInfer: when generalising, we solve all
      the constraints we can so that we don't have to quantify over them
      or, since we don't quantify over constraints in kinds, float them
      and inhibit generalisation.

    * Most signatures also bring implicitly quantified variables into
      scope, and solving is necessary to get these in the right order
      (Step 4) see Note [Keeping implicitly quantified variables in
      order]).

    Note [Kind generalisation]
    ~~~~~~~~~~~~~~~~~~~~~~~~~~
    Step 5 of Note [Recipe for checking a signature], namely
    kind-generalisation, is done by
        kindGeneraliseAll
        kindGeneraliseSome
        kindGeneraliseNone

    Here, we have to deal with the fact that metatyvars generated in the
    type will have a bumped TcLevel, because explicit foralls raise the
    TcLevel. To avoid these variables from ever being visible in the
    surrounding context, we must obey the following dictum:

      Every metavariable in a type must either be
        (A) generalized, or
        (B) promoted, or        See Note [Promotion in signatures]
        (C) a cause to error    See Note [Naughty quantification candidates]
                                in GHC.Tc.Utils.TcMType

    There are three steps (look at kindGeneraliseSome):

    1. candidateQTyVarsOfType finds the free variables of the type or kind,
       to generalise

    2. filterConstrainedCandidates filters out candidates that appear
       in the unsolved 'wanteds', and promotes the ones that get filtered out
       thereby.

    3. quantifyTyVars quantifies the remaining type variables

    The kindGeneralize functions do not require pre-zonking; they zonk as they
    go.

    kindGeneraliseAll specialises for the case where step (2) is vacuous.
    kindGeneraliseNone specialises for the case where we do no quantification,
    but we must still promote.

    If you are actually doing kind-generalization, you need to bump the
    level before generating constraints, as we will only generalize
    variables with a TcLevel higher than the ambient one.
    Hence the "pushLevel" in pushLevelAndSolveEqualities.

    Note [Promotion in signatures]
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    If an unsolved metavariable in a signature is not generalized
    (because we're not generalizing the construct -- e.g., pattern
    sig -- or because the metavars are constrained -- see kindGeneralizeSome)
    we need to promote to maintain (WantedTvInv) of Note [TcLevel invariants]
    in GHC.Tc.Utils.TcType. Note that promotion is identical in effect to generalizing
    and the reinstantiating with a fresh metavariable at the current level.
    So in some sense, we generalize *all* variables, but then re-instantiate
    some of them.

    Here is an example of why we must promote:
      foo (x :: forall a. a -> Proxy b) = ...

    In the pattern signature, `b` is unbound, and will thus be brought into
    scope. We do not know its kind: it will be assigned kappa[2]. Note that
    kappa is at TcLevel 2, because it is invented under a forall. (A priori,
    the kind kappa might depend on `a`, so kappa rightly has a higher TcLevel
    than the surrounding context.) This kappa cannot be solved for while checking
    the pattern signature (which is not kind-generalized). When we are checking
    the *body* of foo, though, we need to unify the type of x with the argument
    type of bar. At this point, the ambient TcLevel is 1, and spotting a
    matavariable with level 2 would violate the (WantedTvInv) invariant of
    Note [TcLevel invariants]. So, instead of kind-generalizing,
    we promote the metavariable to level 1. This is all done in kindGeneralizeNone.

    -}

    funsSigCtxt :: [LocatedN Name] -> UserTypeCtxt
    -- Returns FunSigCtxt, with no redundant-context-reporting,
    -- form a list of located names
    funsSigCtxt :: [GenLocated SrcSpanAnnN Name] -> UserTypeCtxt
    funsSigCtxt (L SrcSpanAnnN
    _ Name
    name1 : [GenLocated SrcSpanAnnN Name]
    _) = Name -> Bool -> UserTypeCtxt
    FunSigCtxt Name
    name1 Bool
    False
    funsSigCtxt []              = String -> UserTypeCtxt
    forall a. String -> a
    panic String
    "funSigCtxt"

    addSigCtxt :: Outputable hs_ty => UserTypeCtxt -> LocatedA hs_ty -> TcM a -> TcM a
    addSigCtxt :: forall hs_ty a.
    Outputable hs_ty =>
    UserTypeCtxt -> LocatedA hs_ty -> TcM a -> TcM a
    addSigCtxt UserTypeCtxt
    ctxt LocatedA hs_ty
    hs_ty TcM a
    thing_inside
      = SrcSpan -> TcM a -> TcM a
    forall a. SrcSpan -> TcRn a -> TcRn a
    setSrcSpan (LocatedA hs_ty -> SrcSpan
    forall a e. GenLocated (SrcSpanAnn' a) e -> SrcSpan
    getLocA LocatedA hs_ty
    hs_ty) (TcM a -> TcM a) -> TcM a -> TcM a
    forall a b. (a -> b) -> a -> b
    $
        SDoc -> TcM a -> TcM a
    forall a. SDoc -> TcM a -> TcM a
    addErrCtxt (UserTypeCtxt -> LocatedA hs_ty -> SDoc
    forall hs_ty.
    Outputable hs_ty =>
    UserTypeCtxt -> LocatedA hs_ty -> SDoc
    pprSigCtxt UserTypeCtxt
    ctxt LocatedA hs_ty
    hs_ty) (TcM a -> TcM a) -> TcM a -> TcM a
    forall a b. (a -> b) -> a -> b
    $
        TcM a
    thing_inside

    pprSigCtxt :: Outputable hs_ty => UserTypeCtxt -> LocatedA hs_ty -> SDoc
    -- (pprSigCtxt ctxt <extra> <type>)
    -- prints    In the type signature for 'f':
    --              f :: <type>
    -- The <extra> is either empty or "the ambiguity check for"
    pprSigCtxt :: forall hs_ty.
    Outputable hs_ty =>
    UserTypeCtxt -> LocatedA hs_ty -> SDoc
    pprSigCtxt UserTypeCtxt
    ctxt LocatedA hs_ty
    hs_ty
      | Just Name
    n <- UserTypeCtxt -> Maybe Name
    isSigMaybe UserTypeCtxt
    ctxt
      = SDoc -> Arity -> SDoc -> SDoc
    hang (String -> SDoc
    text String
    "In the type signature:")
           Arity
    2 (Name -> SDoc
    forall a. OutputableBndr a => a -> SDoc
    pprPrefixOcc Name
    n SDoc -> SDoc -> SDoc
    <+> SDoc
    dcolon SDoc -> SDoc -> SDoc
    <+> LocatedA hs_ty -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr LocatedA hs_ty
    hs_ty)

      | Bool
    otherwise
      = SDoc -> Arity -> SDoc -> SDoc
    hang (String -> SDoc
    text String
    "In" SDoc -> SDoc -> SDoc
    <+> UserTypeCtxt -> SDoc
    pprUserTypeCtxt UserTypeCtxt
    ctxt SDoc -> SDoc -> SDoc
    <> SDoc
    colon)
           Arity
    2 (LocatedA hs_ty -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr LocatedA hs_ty
    hs_ty)

    tcHsSigWcType :: UserTypeCtxt -> LHsSigWcType GhcRn -> TcM Type
    -- This one is used when we have a LHsSigWcType, but in
    -- a place where wildcards aren't allowed. The renamer has
    -- already checked this, so we can simply ignore it.
    tcHsSigWcType :: UserTypeCtxt -> LHsSigWcType GhcRn -> TcM Type
    tcHsSigWcType UserTypeCtxt
    ctxt LHsSigWcType GhcRn
    sig_ty = UserTypeCtxt -> LHsSigType GhcRn -> TcM Type
    tcHsSigType UserTypeCtxt
    ctxt (LHsSigWcType GhcRn -> LHsSigType GhcRn
    forall pass. LHsSigWcType pass -> LHsSigType pass
    dropWildCards LHsSigWcType GhcRn
    sig_ty)

    kcClassSigType :: [LocatedN Name] -> LHsSigType GhcRn -> TcM ()
    -- This is a special form of tcClassSigType that is used during the
    -- kind-checking phase to infer the kind of class variables. Cf. tc_lhs_sig_type.
    -- Importantly, this does *not* kind-generalize. Consider
    --   class SC f where
    --     meth :: forall a (x :: f a). Proxy x -> ()
    -- When instantiating Proxy with kappa, we must unify kappa := f a. But we're
    -- still working out the kind of f, and thus f a will have a coercion in it.
    -- Coercions block unification (Note [Equalities with incompatible kinds] in
    -- TcCanonical) and so we fail to unify. If we try to kind-generalize, we'll
    -- end up promoting kappa to the top level (because kind-generalization is
    -- normally done right before adding a binding to the context), and then we
    -- can't set kappa := f a, because a is local.
    kcClassSigType :: [GenLocated SrcSpanAnnN Name] -> LHsSigType GhcRn -> TcM ()
    kcClassSigType [GenLocated SrcSpanAnnN Name]
    names
        sig_ty :: LHsSigType GhcRn
    sig_ty@(L SrcSpanAnnA
    _ (HsSig { sig_bndrs :: forall pass. HsSigType pass -> HsOuterSigTyVarBndrs pass
    sig_bndrs = HsOuterSigTyVarBndrs GhcRn
    hs_outer_bndrs, sig_body :: forall pass. HsSigType pass -> LHsType pass
    sig_body = LHsType GhcRn
    hs_ty }))
      = UserTypeCtxt
    -> GenLocated SrcSpanAnnA (HsSigType GhcRn) -> TcM () -> TcM ()
    forall hs_ty a.
    Outputable hs_ty =>
    UserTypeCtxt -> LocatedA hs_ty -> TcM a -> TcM a
    addSigCtxt ([GenLocated SrcSpanAnnN Name] -> UserTypeCtxt
    funsSigCtxt [GenLocated SrcSpanAnnN Name]
    names) GenLocated SrcSpanAnnA (HsSigType GhcRn)
    LHsSigType GhcRn
    sig_ty (TcM () -> TcM ()) -> TcM () -> TcM ()
    forall a b. (a -> b) -> a -> b
    $
        do { (HsOuterTyVarBndrs Specificity GhcTc, Type)
    _ <- HsOuterSigTyVarBndrs GhcRn
    -> TcM Type -> TcM (HsOuterTyVarBndrs Specificity GhcTc, Type)
    forall a.
    HsOuterSigTyVarBndrs GhcRn
    -> TcM a -> TcM (HsOuterTyVarBndrs Specificity GhcTc, a)
    bindOuterSigTKBndrs_Tv HsOuterSigTyVarBndrs GhcRn
    hs_outer_bndrs    (TcM Type -> TcM (HsOuterTyVarBndrs Specificity GhcTc, Type))
    -> TcM Type -> TcM (HsOuterTyVarBndrs Specificity GhcTc, Type)
    forall a b. (a -> b) -> a -> b
    $
                  LHsType GhcRn -> Type -> TcM Type
    tcLHsType LHsType GhcRn
    hs_ty Type
    liftedTypeKind
           ; () -> TcM ()
    forall (m :: * -> *) a. Monad m => a -> m a
    return () }

    tcClassSigType :: [LocatedN Name] -> LHsSigType GhcRn -> TcM Type
    -- Does not do validity checking
    tcClassSigType :: [GenLocated SrcSpanAnnN Name] -> LHsSigType GhcRn -> TcM Type
    tcClassSigType [GenLocated SrcSpanAnnN Name]
    names LHsSigType GhcRn
    sig_ty
      = UserTypeCtxt
    -> GenLocated SrcSpanAnnA (HsSigType GhcRn) -> TcM Type -> TcM Type
    forall hs_ty a.
    Outputable hs_ty =>
    UserTypeCtxt -> LocatedA hs_ty -> TcM a -> TcM a
    addSigCtxt UserTypeCtxt
    sig_ctxt GenLocated SrcSpanAnnA (HsSigType GhcRn)
    LHsSigType GhcRn
    sig_ty (TcM Type -> TcM Type) -> TcM Type -> TcM Type
    forall a b. (a -> b) -> a -> b
    $
        do { (Implication
    implic, Type
    ty) <- SkolemInfo
    -> LHsSigType GhcRn -> ContextKind -> TcM (Implication, Type)
    tc_lhs_sig_type SkolemInfo
    skol_info LHsSigType GhcRn
    sig_ty (Type -> ContextKind
    TheKind Type
    liftedTypeKind)
           ; Implication -> TcM ()
    emitImplication Implication
    implic
           ; Type -> TcM Type
    forall (m :: * -> *) a. Monad m => a -> m a
    return Type
    ty }
           -- Do not zonk-to-Type, nor perform a validity check
           -- We are in a knot with the class and associated types
           -- Zonking and validity checking is done by tcClassDecl
           --
           -- No need to fail here if the type has an error:
           --   If we're in the kind-checking phase, the solveEqualities
           --     in kcTyClGroup catches the error
           --   If we're in the type-checking phase, the solveEqualities
           --     in tcClassDecl1 gets it
           -- Failing fast here degrades the error message in, e.g., tcfail135:
           --   class Foo f where
           --     baa :: f a -> f
           -- If we fail fast, we're told that f has kind `k1` when we wanted `*`.
           -- It should be that f has kind `k2 -> *`, but we never get a chance
           -- to run the solver where the kind of f is touchable. This is
           -- painfully delicate.
      where
        sig_ctxt :: UserTypeCtxt
    sig_ctxt = [GenLocated SrcSpanAnnN Name] -> UserTypeCtxt
    funsSigCtxt [GenLocated SrcSpanAnnN Name]
    names
        skol_info :: SkolemInfo
    skol_info = UserTypeCtxt -> SkolemInfo
    SigTypeSkol UserTypeCtxt
    sig_ctxt

    tcHsSigType :: UserTypeCtxt -> LHsSigType GhcRn -> TcM Type
    -- Does validity checking
    -- See Note [Recipe for checking a signature]
    tcHsSigType :: UserTypeCtxt -> LHsSigType GhcRn -> TcM Type
    tcHsSigType UserTypeCtxt
    ctxt LHsSigType GhcRn
    sig_ty
      = UserTypeCtxt
    -> GenLocated SrcSpanAnnA (HsSigType GhcRn) -> TcM Type -> TcM Type
    forall hs_ty a.
    Outputable hs_ty =>
    UserTypeCtxt -> LocatedA hs_ty -> TcM a -> TcM a
    addSigCtxt UserTypeCtxt
    ctxt GenLocated SrcSpanAnnA (HsSigType GhcRn)
    LHsSigType GhcRn
    sig_ty (TcM Type -> TcM Type) -> TcM Type -> TcM Type
    forall a b. (a -> b) -> a -> b
    $
        do { String -> SDoc -> TcM ()
    traceTc String
    "tcHsSigType {" (GenLocated SrcSpanAnnA (HsSigType GhcRn) -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr GenLocated SrcSpanAnnA (HsSigType GhcRn)
    LHsSigType GhcRn
    sig_ty)

              -- Generalise here: see Note [Kind generalisation]
           ; (Implication
    implic, Type
    ty) <- SkolemInfo
    -> LHsSigType GhcRn -> ContextKind -> TcM (Implication, Type)
    tc_lhs_sig_type SkolemInfo
    skol_info LHsSigType GhcRn
    sig_ty  (UserTypeCtxt -> ContextKind
    expectedKindInCtxt UserTypeCtxt
    ctxt)

           -- Float out constraints, failing fast if not possible
           -- See Note [Failure in local type signatures] in GHC.Tc.Solver
           ; String -> SDoc -> TcM ()
    traceTc String
    "tcHsSigType 2" (Implication -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr Implication
    implic)
           ; WantedConstraints -> TcM ()
    simplifyAndEmitFlatConstraints (Bag Implication -> WantedConstraints
    mkImplicWC (Implication -> Bag Implication
    forall a. a -> Bag a
    unitBag Implication
    implic))

           ; Type
    ty <- Type -> TcM Type
    zonkTcType Type
    ty
           ; UserTypeCtxt -> Type -> TcM ()
    checkValidType UserTypeCtxt
    ctxt Type
    ty
           ; String -> SDoc -> TcM ()
    traceTc String
    "end tcHsSigType }" (Type -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr Type
    ty)
           ; Type -> TcM Type
    forall (m :: * -> *) a. Monad m => a -> m a
    return Type
    ty }
      where
        skol_info :: SkolemInfo
    skol_info = UserTypeCtxt -> SkolemInfo
    SigTypeSkol UserTypeCtxt
    ctxt

    tc_lhs_sig_type :: SkolemInfo -> LHsSigType GhcRn
                   -> ContextKind -> TcM (Implication, TcType)
    -- Kind-checks/desugars an 'LHsSigType',
    --   solve equalities,
    --   and then kind-generalizes.
    -- This will never emit constraints, as it uses solveEqualities internally.
    -- No validity checking or zonking
    -- Returns also an implication for the unsolved constraints
    tc_lhs_sig_type :: SkolemInfo
    -> LHsSigType GhcRn -> ContextKind -> TcM (Implication, Type)
    tc_lhs_sig_type SkolemInfo
    skol_info (L SrcSpanAnnA
    loc (HsSig { sig_bndrs :: forall pass. HsSigType pass -> HsOuterSigTyVarBndrs pass
    sig_bndrs = HsOuterSigTyVarBndrs GhcRn
    hs_outer_bndrs
                                           , sig_body :: forall pass. HsSigType pass -> LHsType pass
    sig_body = LHsType GhcRn
    hs_ty })) ContextKind
    ctxt_kind
      = SrcSpanAnnA -> TcM (Implication, Type) -> TcM (Implication, Type)
    forall ann a. SrcSpanAnn' ann -> TcRn a -> TcRn a
    setSrcSpanA SrcSpanAnnA
    loc (TcM (Implication, Type) -> TcM (Implication, Type))
    -> TcM (Implication, Type) -> TcM (Implication, Type)
    forall a b. (a -> b) -> a -> b
    $
        do { (TcLevel
    tc_lvl, WantedConstraints
    wanted, (HsOuterTyVarBndrs Specificity GhcTc
    outer_bndrs, Type
    ty))
                  <- String
    -> TcM (HsOuterTyVarBndrs Specificity GhcTc, Type)
    -> TcM
         (TcLevel, WantedConstraints,
          (HsOuterTyVarBndrs Specificity GhcTc, Type))
    forall a. String -> TcM a -> TcM (TcLevel, WantedConstraints, a)
    pushLevelAndSolveEqualitiesX String
    "tc_lhs_sig_type" (TcM (HsOuterTyVarBndrs Specificity GhcTc, Type)
     -> TcM
          (TcLevel, WantedConstraints,
           (HsOuterTyVarBndrs Specificity GhcTc, Type)))
    -> TcM (HsOuterTyVarBndrs Specificity GhcTc, Type)
    -> TcM
         (TcLevel, WantedConstraints,
          (HsOuterTyVarBndrs Specificity GhcTc, Type))
    forall a b. (a -> b) -> a -> b
    $
                     -- See Note [Failure in local type signatures]
                     SkolemInfo
    -> HsOuterSigTyVarBndrs GhcRn
    -> TcM Type
    -> TcM (HsOuterTyVarBndrs Specificity GhcTc, Type)
    forall flag a.
    OutputableBndrFlag flag 'Renamed =>
    SkolemInfo
    -> HsOuterTyVarBndrs flag GhcRn
    -> TcM a
    -> TcM (HsOuterTyVarBndrs flag GhcTc, a)
    tcOuterTKBndrs SkolemInfo
    skol_info HsOuterSigTyVarBndrs GhcRn
    hs_outer_bndrs (TcM Type -> TcM (HsOuterTyVarBndrs Specificity GhcTc, Type))
    -> TcM Type -> TcM (HsOuterTyVarBndrs Specificity GhcTc, Type)
    forall a b. (a -> b) -> a -> b
    $
                     do { Type
    kind <- ContextKind -> TcM Type
    newExpectedKind ContextKind
    ctxt_kind
                        ; LHsType GhcRn -> Type -> TcM Type
    tcLHsType LHsType GhcRn
    hs_ty Type
    kind }
           -- Any remaining variables (unsolved in the solveEqualities)
           -- should be in the global tyvars, and therefore won't be quantified

           ; String -> SDoc -> TcM ()
    traceTc String
    "tc_lhs_sig_type" (HsOuterSigTyVarBndrs GhcRn -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr HsOuterSigTyVarBndrs GhcRn
    hs_outer_bndrs SDoc -> SDoc -> SDoc
    $$ HsOuterTyVarBndrs Specificity GhcTc -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr HsOuterTyVarBndrs Specificity GhcTc
    outer_bndrs)
           ; ([InvisTVBinder]
    outer_tv_bndrs :: [InvisTVBinder]) <- HsOuterTyVarBndrs Specificity GhcTc -> TcM [InvisTVBinder]
    scopedSortOuter HsOuterTyVarBndrs Specificity GhcTc
    outer_bndrs

           ; let ty1 :: Type
    ty1 = [InvisTVBinder] -> Type -> Type
    mkInvisForAllTys [InvisTVBinder]
    outer_tv_bndrs Type
    ty

           ; [TyVar]
    kvs <- WantedConstraints -> Type -> TcM [TyVar]
    kindGeneralizeSome WantedConstraints
    wanted Type
    ty1

           -- Build an implication for any as-yet-unsolved kind equalities
           -- See Note [Skolem escape in type signatures]
           ; Implication
    implic <- SkolemInfo
    -> [TyVar] -> TcLevel -> WantedConstraints -> TcM Implication
    buildTvImplication SkolemInfo
    skol_info [TyVar]
    kvs TcLevel
    tc_lvl WantedConstraints
    wanted

           ; (Implication, Type) -> TcM (Implication, Type)
    forall (m :: * -> *) a. Monad m => a -> m a
    return (Implication
    implic, [TyVar] -> Type -> Type
    mkInfForAllTys [TyVar]
    kvs Type
    ty1) }

    {- Note [Skolem escape in type signatures]
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    tcHsSigType is tricky.  Consider (T11142)
      foo :: forall b. (forall k (a :: k). SameKind a b) -> ()
    This is ill-kinded because of a nested skolem-escape.

    That will show up as an un-solvable constraint in the implication
    returned by buildTvImplication in tc_lhs_sig_type.  See Note [Skolem
    escape prevention] in GHC.Tc.Utils.TcType for why it is unsolvable
    (the unification variable for b's kind is untouchable).

    Then, in GHC.Tc.Solver.simplifyAndEmitFlatConstraints (called from tcHsSigType)
    we'll try to float out the constraint, be unable to do so, and fail.
    See GHC.Tc.Solver Note [Failure in local type signatures] for more
    detail on this.

    The separation between tcHsSigType and tc_lhs_sig_type is because
    tcClassSigType wants to use the latter, but *not* fail fast, because
    there are skolems from the class decl which are in scope; but it's fine
    not to because tcClassDecl1 has a solveEqualities wrapped around all
    the tcClassSigType calls.

    That's why tcHsSigType does simplifyAndEmitFlatConstraints (which
    fails fast) but tcClassSigType just does emitImplication (which does
    not).  Ugh.

    c.f. see also Note [Skolem escape and forall-types]. The difference
    is that we don't need to simplify at a forall type, only at the
    top level of a signature.
    -}

    -- Does validity checking and zonking.
    tcStandaloneKindSig :: LStandaloneKindSig GhcRn -> TcM (Name, Kind)
    tcStandaloneKindSig :: LStandaloneKindSig GhcRn -> TcM (Name, Type)
    tcStandaloneKindSig (L SrcSpanAnnA
    _ (StandaloneKindSig XStandaloneKindSig GhcRn
    _ (L SrcSpanAnnN
    _ Name
    name) LHsSigType GhcRn
    ksig))
      = UserTypeCtxt
    -> GenLocated SrcSpanAnnA (HsSigType GhcRn)
    -> TcM (Name, Type)
    -> TcM (Name, Type)
    forall hs_ty a.
    Outputable hs_ty =>
    UserTypeCtxt -> LocatedA hs_ty -> TcM a -> TcM a
    addSigCtxt UserTypeCtxt
    ctxt GenLocated SrcSpanAnnA (HsSigType GhcRn)
    LHsSigType GhcRn
    ksig (TcM (Name, Type) -> TcM (Name, Type))
    -> TcM (Name, Type) -> TcM (Name, Type)
    forall a b. (a -> b) -> a -> b
    $
        do { Type
    kind <- TypeOrKind -> UserTypeCtxt -> LHsSigType GhcRn -> TcM Type
    tc_top_lhs_type TypeOrKind
    KindLevel UserTypeCtxt
    ctxt LHsSigType GhcRn
    ksig
           ; UserTypeCtxt -> Type -> TcM ()
    checkValidType UserTypeCtxt
    ctxt Type
    kind
           ; (Name, Type) -> TcM (Name, Type)
    forall (m :: * -> *) a. Monad m => a -> m a
    return (Name
    name, Type
    kind) }
      where
       ctxt :: UserTypeCtxt
    ctxt = Name -> UserTypeCtxt
    StandaloneKindSigCtxt Name
    name

    tcTopLHsType :: UserTypeCtxt -> LHsSigType GhcRn -> TcM Type
    tcTopLHsType :: UserTypeCtxt -> LHsSigType GhcRn -> TcM Type
    tcTopLHsType UserTypeCtxt
    ctxt LHsSigType GhcRn
    lsig_ty
      = TypeOrKind -> UserTypeCtxt -> LHsSigType GhcRn -> TcM Type
    tc_top_lhs_type TypeOrKind
    TypeLevel UserTypeCtxt
    ctxt LHsSigType GhcRn
    lsig_ty

    tc_top_lhs_type :: TypeOrKind -> UserTypeCtxt -> LHsSigType GhcRn -> TcM Type
    -- tc_top_lhs_type is used for kind-checking top-level LHsSigTypes where
    --   we want to fully solve /all/ equalities, and report errors
    -- Does zonking, but not validity checking because it's used
    --   for things (like deriving and instances) that aren't
    --   ordinary types
    -- Used for both types and kinds
    tc_top_lhs_type :: TypeOrKind -> UserTypeCtxt -> LHsSigType GhcRn -> TcM Type
    tc_top_lhs_type TypeOrKind
    tyki UserTypeCtxt
    ctxt (L SrcSpanAnnA
    loc sig_ty :: HsSigType GhcRn
    sig_ty@(HsSig { sig_bndrs :: forall pass. HsSigType pass -> HsOuterSigTyVarBndrs pass
    sig_bndrs = HsOuterSigTyVarBndrs GhcRn
    hs_outer_bndrs
                                                   , sig_body :: forall pass. HsSigType pass -> LHsType pass
    sig_body = LHsType GhcRn
    body }))
      = SrcSpanAnnA -> TcM Type -> TcM Type
    forall ann a. SrcSpanAnn' ann -> TcRn a -> TcRn a
    setSrcSpanA SrcSpanAnnA
    loc (TcM Type -> TcM Type) -> TcM Type -> TcM Type
    forall a b. (a -> b) -> a -> b
    $
        do { String -> SDoc -> TcM ()
    traceTc String
    "tc_top_lhs_type {" (HsSigType GhcRn -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr HsSigType GhcRn
    sig_ty)
           ; (TcLevel
    tclvl, WantedConstraints
    wanted, (HsOuterTyVarBndrs Specificity GhcTc
    outer_bndrs, Type
    ty))
                  <- String
    -> TcM (HsOuterTyVarBndrs Specificity GhcTc, Type)
    -> TcM
         (TcLevel, WantedConstraints,
          (HsOuterTyVarBndrs Specificity GhcTc, Type))
    forall a. String -> TcM a -> TcM (TcLevel, WantedConstraints, a)
    pushLevelAndSolveEqualitiesX String
    "tc_top_lhs_type"    (TcM (HsOuterTyVarBndrs Specificity GhcTc, Type)
     -> TcM
          (TcLevel, WantedConstraints,
           (HsOuterTyVarBndrs Specificity GhcTc, Type)))
    -> TcM (HsOuterTyVarBndrs Specificity GhcTc, Type)
    -> TcM
         (TcLevel, WantedConstraints,
          (HsOuterTyVarBndrs Specificity GhcTc, Type))
    forall a b. (a -> b) -> a -> b
    $
                     SkolemInfo
    -> HsOuterSigTyVarBndrs GhcRn
    -> TcM Type
    -> TcM (HsOuterTyVarBndrs Specificity GhcTc, Type)
    forall flag a.
    OutputableBndrFlag flag 'Renamed =>
    SkolemInfo
    -> HsOuterTyVarBndrs flag GhcRn
    -> TcM a
    -> TcM (HsOuterTyVarBndrs flag GhcTc, a)
    tcOuterTKBndrs SkolemInfo
    skol_info HsOuterSigTyVarBndrs GhcRn
    hs_outer_bndrs (TcM Type -> TcM (HsOuterTyVarBndrs Specificity GhcTc, Type))
    -> TcM Type -> TcM (HsOuterTyVarBndrs Specificity GhcTc, Type)
    forall a b. (a -> b) -> a -> b
    $
                     do { Type
    kind <- ContextKind -> TcM Type
    newExpectedKind (UserTypeCtxt -> ContextKind
    expectedKindInCtxt UserTypeCtxt
    ctxt)
                        ; TcTyMode -> LHsType GhcRn -> Type -> TcM Type
    tc_lhs_type (TypeOrKind -> TcTyMode
    mkMode TypeOrKind
    tyki) LHsType GhcRn
    body Type
    kind }

           ; [InvisTVBinder]
    outer_tv_bndrs <- HsOuterTyVarBndrs Specificity GhcTc -> TcM [InvisTVBinder]
    scopedSortOuter HsOuterTyVarBndrs Specificity GhcTc
    outer_bndrs
           ; let ty1 :: Type
    ty1 = [InvisTVBinder] -> Type -> Type
    mkInvisForAllTys [InvisTVBinder]
    outer_tv_bndrs Type
    ty

           ; [TyVar]
    kvs <- Type -> TcM [TyVar]
    kindGeneralizeAll Type
    ty1  -- "All" because it's a top-level type
           ; SkolemInfo -> [TyVar] -> TcLevel -> WantedConstraints -> TcM ()
    reportUnsolvedEqualities SkolemInfo
    skol_info [TyVar]
    kvs TcLevel
    tclvl WantedConstraints
    wanted

           ; ZonkEnv
    ze       <- ZonkFlexi -> TcM ZonkEnv
    mkEmptyZonkEnv ZonkFlexi
    NoFlexi
           ; Type
    final_ty <- ZonkEnv -> Type -> TcM Type
    zonkTcTypeToTypeX ZonkEnv
    ze ([TyVar] -> Type -> Type
    mkInfForAllTys [TyVar]
    kvs Type
    ty1)
           ; String -> SDoc -> TcM ()
    traceTc String
    "tc_top_lhs_type }" ([SDoc] -> SDoc
    vcat [HsSigType GhcRn -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr HsSigType GhcRn
    sig_ty, Type -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr Type
    final_ty])
           ; Type -> TcM Type
    forall (m :: * -> *) a. Monad m => a -> m a
    return Type
    final_ty }
      where
        skol_info :: SkolemInfo
    skol_info = UserTypeCtxt -> SkolemInfo
    SigTypeSkol UserTypeCtxt
    ctxt

    -----------------
    tcHsDeriv :: LHsSigType GhcRn -> TcM ([TyVar], Class, [Type], [Kind])
    -- Like tcHsSigType, but for the ...deriving( C t1 ty2 ) clause
    -- Returns the C, [ty1, ty2, and the kinds of C's remaining arguments
    -- E.g.    class C (a::*) (b::k->k)
    --         data T a b = ... deriving( C Int )
    --    returns ([k], C, [k, Int], [k->k])
    -- Return values are fully zonked
    tcHsDeriv :: LHsSigType GhcRn -> TcM ([TyVar], Class, [Type], [Type])
    tcHsDeriv LHsSigType GhcRn
    hs_ty
      = do { Type
    ty <- TcM Type -> TcM Type
    forall r. TcM r -> TcM r
    checkNoErrs (TcM Type -> TcM Type) -> TcM Type -> TcM Type
    forall a b. (a -> b) -> a -> b
    $  -- Avoid redundant error report
                                  -- with "illegal deriving", below
                   UserTypeCtxt -> LHsSigType GhcRn -> TcM Type
    tcTopLHsType UserTypeCtxt
    DerivClauseCtxt LHsSigType GhcRn
    hs_ty
           ; let ([TyVar]
    tvs, Type
    pred)    = Type -> ([TyVar], Type)
    splitForAllTyCoVars Type
    ty
                 ([Scaled Type]
    kind_args, Type
    _) = Type -> ([Scaled Type], Type)
    splitFunTys (HasDebugCallStack => Type -> Type
    Type -> Type
    tcTypeKind Type
    pred)
           ; case Type -> Maybe (Class, [Type])
    getClassPredTys_maybe Type
    pred of
               Just (Class
    cls, [Type]
    tys) -> ([TyVar], Class, [Type], [Type])
    -> TcM ([TyVar], Class, [Type], [Type])
    forall (m :: * -> *) a. Monad m => a -> m a
    return ([TyVar]
    tvs, Class
    cls, [Type]
    tys, (Scaled Type -> Type) -> [Scaled Type] -> [Type]
    forall a b. (a -> b) -> [a] -> [b]
    map Scaled Type -> Type
    forall a. Scaled a -> a
    scaledThing [Scaled Type]
    kind_args)
               Maybe (Class, [Type])
    Nothing -> SDoc -> TcM ([TyVar], Class, [Type], [Type])
    forall a. SDoc -> TcM a
    failWithTc (String -> SDoc
    text String
    "Illegal deriving item" SDoc -> SDoc -> SDoc
    <+> SDoc -> SDoc
    quotes (GenLocated SrcSpanAnnA (HsSigType GhcRn) -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr GenLocated SrcSpanAnnA (HsSigType GhcRn)
    LHsSigType GhcRn
    hs_ty)) }

    -- | Typecheck a deriving strategy. For most deriving strategies, this is a
    -- no-op, but for the @via@ strategy, this requires typechecking the @via@ type.
    tcDerivStrategy ::
         Maybe (LDerivStrategy GhcRn)
         -- ^ The deriving strategy
      -> TcM (Maybe (LDerivStrategy GhcTc), [TyVar])
         -- ^ The typechecked deriving strategy and the tyvars that it binds
         -- (if using 'ViaStrategy').
    tcDerivStrategy :: Maybe (LDerivStrategy GhcRn)
    -> TcM (Maybe (LDerivStrategy GhcTc), [TyVar])
    tcDerivStrategy Maybe (LDerivStrategy GhcRn)
    mb_lds
      = case Maybe (LDerivStrategy GhcRn)
    mb_lds of
          Maybe (LDerivStrategy GhcRn)
    Nothing -> Maybe (GenLocated SrcSpan (DerivStrategy GhcTc))
    -> TcM (Maybe (GenLocated SrcSpan (DerivStrategy GhcTc)), [TyVar])
    forall ds. ds -> TcM (ds, [TyVar])
    boring_case Maybe (GenLocated SrcSpan (DerivStrategy GhcTc))
    forall a. Maybe a
    Nothing
          Just (L SrcSpan
    loc DerivStrategy GhcRn
    ds) ->
            SrcSpan
    -> TcM (Maybe (LDerivStrategy GhcTc), [TyVar])
    -> TcM (Maybe (LDerivStrategy GhcTc), [TyVar])
    forall a. SrcSpan -> TcRn a -> TcRn a
    setSrcSpan SrcSpan
    loc (TcM (Maybe (LDerivStrategy GhcTc), [TyVar])
     -> TcM (Maybe (LDerivStrategy GhcTc), [TyVar]))
    -> TcM (Maybe (LDerivStrategy GhcTc), [TyVar])
    -> TcM (Maybe (LDerivStrategy GhcTc), [TyVar])
    forall a b. (a -> b) -> a -> b
    $ do
              (DerivStrategy GhcTc
    ds', [TyVar]
    tvs) <- DerivStrategy GhcRn -> TcM (DerivStrategy GhcTc, [TyVar])
    tc_deriv_strategy DerivStrategy GhcRn
    ds
              (Maybe (GenLocated SrcSpan (DerivStrategy GhcTc)), [TyVar])
    -> TcM (Maybe (GenLocated SrcSpan (DerivStrategy GhcTc)), [TyVar])
    forall (f :: * -> *) a. Applicative f => a -> f a
    pure (GenLocated SrcSpan (DerivStrategy GhcTc)
    -> Maybe (GenLocated SrcSpan (DerivStrategy GhcTc))
    forall a. a -> Maybe a
    Just (SrcSpan
    -> DerivStrategy GhcTc -> GenLocated SrcSpan (DerivStrategy GhcTc)
    forall l e. l -> e -> GenLocated l e
    L SrcSpan
    loc DerivStrategy GhcTc
    ds'), [TyVar]
    tvs)
      where
        tc_deriv_strategy :: DerivStrategy GhcRn
                          -> TcM (DerivStrategy GhcTc, [TyVar])
        tc_deriv_strategy :: DerivStrategy GhcRn -> TcM (DerivStrategy GhcTc, [TyVar])
    tc_deriv_strategy (StockStrategy    XStockStrategy GhcRn
    _)
                                         = DerivStrategy GhcTc -> TcM (DerivStrategy GhcTc, [TyVar])
    forall ds. ds -> TcM (ds, [TyVar])
    boring_case (XStockStrategy GhcTc -> DerivStrategy GhcTc
    forall pass. XStockStrategy pass -> DerivStrategy pass
    StockStrategy NoExtField
    XStockStrategy GhcTc
    noExtField)
        tc_deriv_strategy (AnyclassStrategy XAnyClassStrategy GhcRn
    _)
                                         = DerivStrategy GhcTc -> TcM (DerivStrategy GhcTc, [TyVar])
    forall ds. ds -> TcM (ds, [TyVar])
    boring_case (XAnyClassStrategy GhcTc -> DerivStrategy GhcTc
    forall pass. XAnyClassStrategy pass -> DerivStrategy pass
    AnyclassStrategy NoExtField
    XAnyClassStrategy GhcTc
    noExtField)
        tc_deriv_strategy (NewtypeStrategy  XNewtypeStrategy GhcRn
    _)
                                         = DerivStrategy GhcTc -> TcM (DerivStrategy GhcTc, [TyVar])
    forall ds. ds -> TcM (ds, [TyVar])
    boring_case (XNewtypeStrategy GhcTc -> DerivStrategy GhcTc
    forall pass. XNewtypeStrategy pass -> DerivStrategy pass
    NewtypeStrategy NoExtField
    XNewtypeStrategy GhcTc
    noExtField)
        tc_deriv_strategy (ViaStrategy XViaStrategy GhcRn
    ty) = do
          Type
    ty' <- TcM Type -> TcM Type
    forall r. TcM r -> TcM r
    checkNoErrs (TcM Type -> TcM Type) -> TcM Type -> TcM Type
    forall a b. (a -> b) -> a -> b
    $ UserTypeCtxt -> LHsSigType GhcRn -> TcM Type
    tcTopLHsType UserTypeCtxt
    DerivClauseCtxt LHsSigType GhcRn
    XViaStrategy GhcRn
    ty
          let ([TyVar]
    via_tvs, Type
    via_pred) = Type -> ([TyVar], Type)
    splitForAllTyCoVars Type
    ty'
          (DerivStrategy GhcTc, [TyVar])
    -> TcM (DerivStrategy GhcTc, [TyVar])
    forall (f :: * -> *) a. Applicative f => a -> f a
    pure (XViaStrategy GhcTc -> DerivStrategy GhcTc
    forall pass. XViaStrategy pass -> DerivStrategy pass
    ViaStrategy Type
    XViaStrategy GhcTc
    via_pred, [TyVar]
    via_tvs)

        boring_case :: ds -> TcM (ds, [TyVar])
        boring_case :: forall ds. ds -> TcM (ds, [TyVar])
    boring_case ds
    ds = (ds, [TyVar]) -> IOEnv (Env TcGblEnv TcLclEnv) (ds, [TyVar])
    forall (f :: * -> *) a. Applicative f => a -> f a
    pure (ds
    ds, [])

    tcHsClsInstType :: UserTypeCtxt    -- InstDeclCtxt or SpecInstCtxt
                    -> LHsSigType GhcRn
                    -> TcM Type
    -- Like tcHsSigType, but for a class instance declaration
    tcHsClsInstType :: UserTypeCtxt -> LHsSigType GhcRn -> TcM Type
    tcHsClsInstType UserTypeCtxt
    user_ctxt LHsSigType GhcRn
    hs_inst_ty
      = SrcSpan -> TcM Type -> TcM Type
    forall a. SrcSpan -> TcRn a -> TcRn a
    setSrcSpan (GenLocated SrcSpanAnnA (HsSigType GhcRn) -> SrcSpan
    forall a e. GenLocated (SrcSpanAnn' a) e -> SrcSpan
    getLocA GenLocated SrcSpanAnnA (HsSigType GhcRn)
    LHsSigType GhcRn
    hs_inst_ty) (TcM Type -> TcM Type) -> TcM Type -> TcM Type
    forall a b. (a -> b) -> a -> b
    $
        do { -- Fail eagerly if tcTopLHsType fails.  We are at top level so
             -- these constraints will never be solved later. And failing
             -- eagerly avoids follow-on errors when checkValidInstance
             -- sees an unsolved coercion hole
             Type
    inst_ty <- TcM Type -> TcM Type
    forall r. TcM r -> TcM r
    checkNoErrs (TcM Type -> TcM Type) -> TcM Type -> TcM Type
    forall a b. (a -> b) -> a -> b
    $
                        UserTypeCtxt -> LHsSigType GhcRn -> TcM Type
    tcTopLHsType UserTypeCtxt
    user_ctxt LHsSigType GhcRn
    hs_inst_ty
           ; UserTypeCtxt -> LHsSigType GhcRn -> Type -> TcM ()
    checkValidInstance UserTypeCtxt
    user_ctxt LHsSigType GhcRn
    hs_inst_ty Type
    inst_ty
           ; Type -> TcM Type
    forall (m :: * -> *) a. Monad m => a -> m a
    return Type
    inst_ty }

    ----------------------------------------------
    -- | Type-check a visible type application
    tcHsTypeApp :: LHsWcType GhcRn -> Kind -> TcM Type
    -- See Note [Recipe for checking a signature] in GHC.Tc.Gen.HsType
    tcHsTypeApp :: LHsWcType GhcRn -> Type -> TcM Type
    tcHsTypeApp LHsWcType GhcRn
    wc_ty Type
    kind
      | HsWC { hswc_ext :: forall pass thing. HsWildCardBndrs pass thing -> XHsWC pass thing
    hswc_ext = XHsWC GhcRn (LHsType GhcRn)
    sig_wcs, hswc_body :: forall pass thing. HsWildCardBndrs pass thing -> thing
    hswc_body = LHsType GhcRn
    hs_ty } <- LHsWcType GhcRn
    wc_ty
      = do { TcTyMode
    mode <- TypeOrKind -> HoleMode -> TcM TcTyMode
    mkHoleMode TypeOrKind
    TypeLevel HoleMode
    HM_VTA
                     -- HM_VTA: See Note [Wildcards in visible type application]
           ; Type
    ty <- LHsType GhcRn -> TcM Type -> TcM Type
    forall a. LHsType GhcRn -> TcM a -> TcM a
    addTypeCtxt LHsType GhcRn
    hs_ty                  (TcM Type -> TcM Type) -> TcM Type -> TcM Type
    forall a b. (a -> b) -> a -> b
    $
                   String -> TcM Type -> TcM Type
    forall a. String -> TcM a -> TcM a
    solveEqualities String
    "tcHsTypeApp" (TcM Type -> TcM Type) -> TcM Type -> TcM Type
    forall a b. (a -> b) -> a -> b
    $
                   -- We are looking at a user-written type, very like a
                   -- signature so we want to solve its equalities right now
                   HsQTvsRn -> ([(Name, TyVar)] -> TcM Type) -> TcM Type
    forall a. HsQTvsRn -> ([(Name, TyVar)] -> TcM a) -> TcM a
    bindNamedWildCardBinders HsQTvsRn
    XHsWC GhcRn (LHsType GhcRn)
    sig_wcs (([(Name, TyVar)] -> TcM Type) -> TcM Type)
    -> ([(Name, TyVar)] -> TcM Type) -> TcM Type
    forall a b. (a -> b) -> a -> b
    $ \ [(Name, TyVar)]
    _ ->
                   TcTyMode -> LHsType GhcRn -> Type -> TcM Type
    tc_lhs_type TcTyMode
    mode LHsType GhcRn
    hs_ty Type
    kind

           -- We do not kind-generalize type applications: we just
           -- instantiate with exactly what the user says.
           -- See Note [No generalization in type application]
           -- We still must call kindGeneralizeNone, though, according
           -- to Note [Recipe for checking a signature]
           ; Type -> TcM ()
    kindGeneralizeNone Type
    ty
           ; Type
    ty <- Type -> TcM Type
    zonkTcType Type
    ty
           ; UserTypeCtxt -> Type -> TcM ()
    checkValidType UserTypeCtxt
    TypeAppCtxt Type
    ty
           ; Type -> TcM Type
    forall (m :: * -> *) a. Monad m => a -> m a
    return Type
    ty }

    {- Note [Wildcards in visible type application]
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    A HsWildCardBndrs's hswc_ext now only includes /named/ wildcards, so
    any unnamed wildcards stay unchanged in hswc_body.  When called in
    tcHsTypeApp, tcCheckLHsType will call emitAnonTypeHole
    on these anonymous wildcards. However, this would trigger
    error/warning when an anonymous wildcard is passed in as a visible type
    argument, which we do not want because users should be able to write
    @_ to skip a instantiating a type variable variable without fuss. The
    solution is to switch the PartialTypeSignatures flags here to let the
    typechecker know that it's checking a '@_' and do not emit hole
    constraints on it.  See related Note [Wildcards in visible kind
    application] and Note [The wildcard story for types] in GHC.Hs.Type

    Ugh!

    Note [No generalization in type application]
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    We do not kind-generalize type applications. Imagine

      id @(Proxy Nothing)

    If we kind-generalized, we would get

      id @(forall {k}. Proxy @(Maybe k) (Nothing @k))

    which is very sneakily impredicative instantiation.

    There is also the possibility of mentioning a wildcard
    (`id @(Proxy _)`), which definitely should not be kind-generalized.

    -}

    tcFamTyPats :: TyCon
                -> HsTyPats GhcRn                -- Patterns
                -> TcM (TcType, TcKind)          -- (lhs_type, lhs_kind)
    -- Check the LHS of a type/data family instance
    -- e.g.   type instance F ty1 .. tyn = ...
    -- Used for both type and data families
    tcFamTyPats :: TyCon -> HsTyPats GhcRn -> TcM (Type, Type)
    tcFamTyPats TyCon
    fam_tc HsTyPats GhcRn
    hs_pats
      = do { String -> SDoc -> TcM ()
    traceTc String
    "tcFamTyPats {" (SDoc -> TcM ()) -> SDoc -> TcM ()
    forall a b. (a -> b) -> a -> b
    $
             [SDoc] -> SDoc
    vcat [ TyCon -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr TyCon
    fam_tc, String -> SDoc
    text String
    "arity:" SDoc -> SDoc -> SDoc
    <+> Arity -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr Arity
    fam_arity ]

           ; TcTyMode
    mode <- TypeOrKind -> HoleMode -> TcM TcTyMode
    mkHoleMode TypeOrKind
    TypeLevel HoleMode
    HM_FamPat
                     -- HM_FamPat: See Note [Wildcards in family instances] in
                     -- GHC.Rename.Module
           ; let fun_ty :: Type
    fun_ty = TyCon -> [Type] -> Type
    mkTyConApp TyCon
    fam_tc []
           ; (Type
    fam_app, Type
    res_kind) <- TcTyMode
    -> LHsType GhcRn -> Type -> HsTyPats GhcRn -> TcM (Type, Type)
    tcInferTyApps TcTyMode
    mode GenLocated SrcSpanAnnA (HsType GhcRn)
    LHsType GhcRn
    lhs_fun Type
    fun_ty HsTyPats GhcRn
    hs_pats

           -- Hack alert: see Note [tcFamTyPats: zonking the result kind]
           ; Type
    res_kind <- Type -> TcM Type
    zonkTcType Type
    res_kind

           ; String -> SDoc -> TcM ()
    traceTc String
    "End tcFamTyPats }" (SDoc -> TcM ()) -> SDoc -> TcM ()
    forall a b. (a -> b) -> a -> b
    $
             [SDoc] -> SDoc
    vcat [ TyCon -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr TyCon
    fam_tc, String -> SDoc
    text String
    "res_kind:" SDoc -> SDoc -> SDoc
    <+> Type -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr Type
    res_kind ]

           ; (Type, Type) -> TcM (Type, Type)
    forall (m :: * -> *) a. Monad m => a -> m a
    return (Type
    fam_app, Type
    res_kind) }
      where
        fam_name :: Name
    fam_name  = TyCon -> Name
    tyConName TyCon
    fam_tc
        fam_arity :: Arity
    fam_arity = TyCon -> Arity
    tyConArity TyCon
    fam_tc
        lhs_fun :: GenLocated SrcSpanAnnA (HsType GhcRn)
    lhs_fun   = HsType GhcRn -> GenLocated SrcSpanAnnA (HsType GhcRn)
    forall a an. a -> LocatedAn an a
    noLocA (XTyVar GhcRn -> PromotionFlag -> LIdP GhcRn -> HsType GhcRn
    forall pass.
    XTyVar pass -> PromotionFlag -> LIdP pass -> HsType pass
    HsTyVar XTyVar GhcRn
    forall a. EpAnn a
    noAnn PromotionFlag
    NotPromoted (Name -> GenLocated SrcSpanAnnN Name
    forall a an. a -> LocatedAn an a
    noLocA Name
    fam_name))

    {- Note [tcFamTyPats: zonking the result kind]
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    Consider (#19250)
        F :: forall k. k -> k
        type instance F (x :: Constraint) = ()

    The tricky point is this:
      is that () an empty type tuple (() :: Type), or
      an empty constraint tuple (() :: Constraint)?
    We work this out in a hacky way, by looking at the expected kind:
    see Note [Inferring tuple kinds].

    In this case, we kind-check the RHS using the kind gotten from the LHS:
    see the call to tcCheckLHsType in tcTyFamInstEqnGuts in GHC.Tc.Tycl.

    But we want the kind from the LHS to be /zonked/, so that when
    kind-checking the RHS (tcCheckLHsType) we can "see" what we learned
    from kind-checking the LHS (tcFamTyPats).  In our example above, the
    type of the LHS is just `kappa` (by instantiating the forall k), but
    then we learn (from x::Constraint) that kappa ~ Constraint.  We want
    that info when kind-checking the RHS.

    Easy solution: just zonk that return kind.  Of course this won't help
    if there is lots of type-family reduction to do, but it works fine in
    common cases.
    -}

    {-
    ************************************************************************
    *                                                                      *
                The main kind checker: no validity checks here
    *                                                                      *
    ************************************************************************
    -}

    ---------------------------
    tcHsOpenType, tcHsLiftedType,
      tcHsOpenTypeNC, tcHsLiftedTypeNC :: LHsType GhcRn -> TcM TcType
    -- Used for type signatures
    -- Do not do validity checking
    tcHsOpenType :: LHsType GhcRn -> TcM Type
    tcHsOpenType   LHsType GhcRn
    hs_ty = LHsType GhcRn -> TcM Type -> TcM Type
    forall a. LHsType GhcRn -> TcM a -> TcM a
    addTypeCtxt LHsType GhcRn
    hs_ty (TcM Type -> TcM Type) -> TcM Type -> TcM Type
    forall a b. (a -> b) -> a -> b
    $ LHsType GhcRn -> TcM Type
    tcHsOpenTypeNC LHsType GhcRn
    hs_ty
    tcHsLiftedType :: LHsType GhcRn -> TcM Type
    tcHsLiftedType LHsType GhcRn
    hs_ty = LHsType GhcRn -> TcM Type -> TcM Type
    forall a. LHsType GhcRn -> TcM a -> TcM a
    addTypeCtxt LHsType GhcRn
    hs_ty (TcM Type -> TcM Type) -> TcM Type -> TcM Type
    forall a b. (a -> b) -> a -> b
    $ LHsType GhcRn -> TcM Type
    tcHsLiftedTypeNC LHsType GhcRn
    hs_ty

    tcHsOpenTypeNC :: LHsType GhcRn -> TcM Type
    tcHsOpenTypeNC   LHsType GhcRn
    hs_ty = do { Type
    ek <- TcM Type
    newOpenTypeKind; LHsType GhcRn -> Type -> TcM Type
    tcLHsType LHsType GhcRn
    hs_ty Type
    ek }
    tcHsLiftedTypeNC :: LHsType GhcRn -> TcM Type
    tcHsLiftedTypeNC LHsType GhcRn
    hs_ty = LHsType GhcRn -> Type -> TcM Type
    tcLHsType LHsType GhcRn
    hs_ty Type
    liftedTypeKind

    -- Like tcHsType, but takes an expected kind
    tcCheckLHsType :: LHsType GhcRn -> ContextKind -> TcM TcType
    tcCheckLHsType :: LHsType GhcRn -> ContextKind -> TcM Type
    tcCheckLHsType LHsType GhcRn
    hs_ty ContextKind
    exp_kind
      = LHsType GhcRn -> TcM Type -> TcM Type
    forall a. LHsType GhcRn -> TcM a -> TcM a
    addTypeCtxt LHsType GhcRn
    hs_ty (TcM Type -> TcM Type) -> TcM Type -> TcM Type
    forall a b. (a -> b) -> a -> b
    $
        do { Type
    ek <- ContextKind -> TcM Type
    newExpectedKind ContextKind
    exp_kind
           ; LHsType GhcRn -> Type -> TcM Type
    tcLHsType LHsType GhcRn
    hs_ty Type
    ek }

    tcInferLHsType :: LHsType GhcRn -> TcM TcType
    tcInferLHsType :: LHsType GhcRn -> TcM Type
    tcInferLHsType LHsType GhcRn
    hs_ty
      = do { (Type
    ty,Type
    _kind) <- LHsType GhcRn -> TcM (Type, Type)
    tcInferLHsTypeKind LHsType GhcRn
    hs_ty
           ; Type -> TcM Type
    forall (m :: * -> *) a. Monad m => a -> m a
    return Type
    ty }

    tcInferLHsTypeKind :: LHsType GhcRn -> TcM (TcType, TcKind)
    -- Called from outside: set the context
    -- Eagerly instantiate any trailing invisible binders
    tcInferLHsTypeKind :: LHsType GhcRn -> TcM (Type, Type)
    tcInferLHsTypeKind lhs_ty :: LHsType GhcRn
    lhs_ty@(L SrcSpanAnnA
    loc HsType GhcRn
    hs_ty)
      = LHsType GhcRn -> TcM (Type, Type) -> TcM (Type, Type)
    forall a. LHsType GhcRn -> TcM a -> TcM a
    addTypeCtxt LHsType GhcRn
    lhs_ty (TcM (Type, Type) -> TcM (Type, Type))
    -> TcM (Type, Type) -> TcM (Type, Type)
    forall a b. (a -> b) -> a -> b
    $
        SrcSpanAnnA -> TcM (Type, Type) -> TcM (Type, Type)
    forall ann a. SrcSpanAnn' ann -> TcRn a -> TcRn a
    setSrcSpanA SrcSpanAnnA
    loc    (TcM (Type, Type) -> TcM (Type, Type))
    -> TcM (Type, Type) -> TcM (Type, Type)
    forall a b. (a -> b) -> a -> b
    $  -- Cover the tcInstInvisibleTyBinders
        do { (Type
    res_ty, Type
    res_kind) <- TcTyMode -> HsType GhcRn -> TcM (Type, Type)
    tc_infer_hs_type TcTyMode
    typeLevelMode HsType GhcRn
    hs_ty
           ; Type -> Type -> TcM (Type, Type)
    tcInstInvisibleTyBinders Type
    res_ty Type
    res_kind }
      -- See Note [Do not always instantiate eagerly in types]

    -- Used to check the argument of GHCi :kind
    -- Allow and report wildcards, e.g. :kind T _
    -- Do not saturate family applications: see Note [Dealing with :kind]
    -- Does not instantiate eagerly; See Note [Do not always instantiate eagerly in types]
    tcInferLHsTypeUnsaturated :: LHsType GhcRn -> TcM (TcType, TcKind)
    tcInferLHsTypeUnsaturated :: LHsType GhcRn -> TcM (Type, Type)
    tcInferLHsTypeUnsaturated LHsType GhcRn
    hs_ty
      = LHsType GhcRn -> TcM (Type, Type) -> TcM (Type, Type)
    forall a. LHsType GhcRn -> TcM a -> TcM a
    addTypeCtxt LHsType GhcRn
    hs_ty (TcM (Type, Type) -> TcM (Type, Type))
    -> TcM (Type, Type) -> TcM (Type, Type)
    forall a b. (a -> b) -> a -> b
    $
        do { TcTyMode
    mode <- TypeOrKind -> HoleMode -> TcM TcTyMode
    mkHoleMode TypeOrKind
    TypeLevel HoleMode
    HM_Sig  -- Allow and report holes
           ; case HsType GhcRn -> Maybe (LHsType GhcRn, HsTyPats GhcRn)
    splitHsAppTys (GenLocated SrcSpanAnnA (HsType GhcRn) -> HsType GhcRn
    forall l e. GenLocated l e -> e
    unLoc GenLocated SrcSpanAnnA (HsType GhcRn)
    LHsType GhcRn
    hs_ty) of
               Just (LHsType GhcRn
    hs_fun_ty, HsTyPats GhcRn
    hs_args)
                  -> do { (Type
    fun_ty, Type
    _ki) <- TcTyMode -> LHsType GhcRn -> TcM (Type, Type)
    tcInferTyAppHead TcTyMode
    mode LHsType GhcRn
    hs_fun_ty
                        ; TcTyMode
    -> LHsType GhcRn -> Type -> HsTyPats GhcRn -> TcM (Type, Type)
    tcInferTyApps_nosat TcTyMode
    mode LHsType GhcRn
    hs_fun_ty Type
    fun_ty HsTyPats GhcRn
    hs_args }
                          -- Notice the 'nosat'; do not instantiate trailing
                          -- invisible arguments of a type family.
                          -- See Note [Dealing with :kind]
               Maybe (LHsType GhcRn, HsTyPats GhcRn)
    Nothing -> TcTyMode -> LHsType GhcRn -> TcM (Type, Type)
    tc_infer_lhs_type TcTyMode
    mode LHsType GhcRn
    hs_ty }

    {- Note [Dealing with :kind]
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~
    Consider this GHCi command
      ghci> type family F :: Either j k
      ghci> :kind F
      F :: forall {j,k}. Either j k

    We will only get the 'forall' if we /refrain/ from saturating those
    invisible binders. But generally we /do/ saturate those invisible
    binders (see tcInferTyApps), and we want to do so for nested application
    even in GHCi.  Consider for example (#16287)
      ghci> type family F :: k
      ghci> data T :: (forall k. k) -> Type
      ghci> :kind T F
    We want to reject this. It's just at the very top level that we want
    to switch off saturation.

    So tcInferLHsTypeUnsaturated does a little special case for top level
    applications.  Actually the common case is a bare variable, as above.

    Note [Do not always instantiate eagerly in types]
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    Terms are eagerly instantiated. This means that if you say

      x = id

    then `id` gets instantiated to have type alpha -> alpha. The variable
    alpha is then unconstrained and regeneralized. But we cannot do this
    in types, as we have no type-level lambda. So, when we are sure
    that we will not want to regeneralize later -- because we are done
    checking a type, for example -- we can instantiate. But we do not
    instantiate at variables, nor do we in tcInferLHsTypeUnsaturated,
    which is used by :kind in GHCi.

    ************************************************************************
    *                                                                      *
          Type-checking modes
    *                                                                      *
    ************************************************************************

    The kind-checker is parameterised by a TcTyMode, which contains some
    information about where we're checking a type.

    The renamer issues errors about what it can. All errors issued here must
    concern things that the renamer can't handle.

    -}

    tcMult :: HsArrow GhcRn -> TcM Mult
    tcMult :: HsArrow GhcRn -> TcM Type
    tcMult HsArrow GhcRn
    hc = TcTyMode -> HsArrow GhcRn -> TcM Type
    tc_mult TcTyMode
    typeLevelMode HsArrow GhcRn
    hc

    -- | Info about the context in which we're checking a type. Currently,
    -- differentiates only between types and kinds, but this will likely
    -- grow, at least to include the distinction between patterns and
    -- not-patterns.
    --
    -- To find out where the mode is used, search for 'mode_tyki'
    --
    -- This data type is purely local, not exported from this module
    data TcTyMode
      = TcTyMode { TcTyMode -> TypeOrKind
    mode_tyki :: TypeOrKind
                 , TcTyMode -> HoleInfo
    mode_holes :: HoleInfo   }

    -- See Note [Levels for wildcards]
    -- Nothing <=> no wildcards expected
    type HoleInfo = Maybe (TcLevel, HoleMode)

    -- HoleMode says how to treat the occurrences
    -- of anonymous wildcards; see tcAnonWildCardOcc
    data HoleMode = HM_Sig      -- Partial type signatures: f :: _ -> Int
                  | HM_FamPat   -- Family instances: F _ Int = Bool
                  | HM_VTA      -- Visible type and kind application:
                                --   f @(Maybe _)
                                --   Maybe @(_ -> _)
                  | HM_TyAppPat -- Visible type applications in patterns:
                                --   foo (Con @_ @t x) = ...
                                --   case x of Con @_ @t v -> ...

    mkMode :: TypeOrKind -> TcTyMode
    mkMode :: TypeOrKind -> TcTyMode
    mkMode TypeOrKind
    tyki = TcTyMode { mode_tyki :: TypeOrKind
    mode_tyki = TypeOrKind
    tyki, mode_holes :: HoleInfo
    mode_holes = HoleInfo
    forall a. Maybe a
    Nothing }

    typeLevelMode, kindLevelMode :: TcTyMode
    -- These modes expect no wildcards (holes) in the type
    kindLevelMode :: TcTyMode
    kindLevelMode = TypeOrKind -> TcTyMode
    mkMode TypeOrKind
    KindLevel
    typeLevelMode :: TcTyMode
    typeLevelMode = TypeOrKind -> TcTyMode
    mkMode TypeOrKind
    TypeLevel

    mkHoleMode :: TypeOrKind -> HoleMode -> TcM TcTyMode
    mkHoleMode :: TypeOrKind -> HoleMode -> TcM TcTyMode
    mkHoleMode TypeOrKind
    tyki HoleMode
    hm
      = do { TcLevel
    lvl <- TcM TcLevel
    getTcLevel
           ; TcTyMode -> TcM TcTyMode
    forall (m :: * -> *) a. Monad m => a -> m a
    return (TcTyMode { mode_tyki :: TypeOrKind
    mode_tyki  = TypeOrKind
    tyki
                              , mode_holes :: HoleInfo
    mode_holes = (TcLevel, HoleMode) -> HoleInfo
    forall a. a -> Maybe a
    Just (TcLevel
    lvl,HoleMode
    hm) }) }

    instance Outputable HoleMode where
      ppr :: HoleMode -> SDoc
    ppr HoleMode
    HM_Sig      = String -> SDoc
    text String
    "HM_Sig"
      ppr HoleMode
    HM_FamPat   = String -> SDoc
    text String
    "HM_FamPat"
      ppr HoleMode
    HM_VTA      = String -> SDoc
    text String
    "HM_VTA"
      ppr HoleMode
    HM_TyAppPat = String -> SDoc
    text String
    "HM_TyAppPat"

    instance Outputable TcTyMode where
      ppr :: TcTyMode -> SDoc
    ppr (TcTyMode { mode_tyki :: TcTyMode -> TypeOrKind
    mode_tyki = TypeOrKind
    tyki, mode_holes :: TcTyMode -> HoleInfo
    mode_holes = HoleInfo
    hm })
        = String -> SDoc
    text String
    "TcTyMode" SDoc -> SDoc -> SDoc
    <+> SDoc -> SDoc
    braces ([SDoc] -> SDoc
    sep [ TypeOrKind -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr TypeOrKind
    tyki SDoc -> SDoc -> SDoc
    <> SDoc
    comma
                                          , HoleInfo -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr HoleInfo
    hm ])

    {-
    Note [Bidirectional type checking]
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    In expressions, whenever we see a polymorphic identifier, say `id`, we are
    free to instantiate it with metavariables, knowing that we can always
    re-generalize with type-lambdas when necessary. For example:

      rank2 :: (forall a. a -> a) -> ()
      x = rank2 id

    When checking the body of `x`, we can instantiate `id` with a metavariable.
    Then, when we're checking the application of `rank2`, we notice that we really
    need a polymorphic `id`, and then re-generalize over the unconstrained
    metavariable.

    In types, however, we're not so lucky, because *we cannot re-generalize*!
    There is no lambda. So, we must be careful only to instantiate at the last
    possible moment, when we're sure we're never going to want the lost polymorphism
    again. This is done in calls to tcInstInvisibleTyBinders.

    To implement this behavior, we use bidirectional type checking, where we
    explicitly think about whether we know the kind of the type we're checking
    or not. Note that there is a difference between not knowing a kind and
    knowing a metavariable kind: the metavariables are TauTvs, and cannot become
    forall-quantified kinds. Previously (before dependent types), there were
    no higher-rank kinds, and so we could instantiate early and be sure that
    no types would have polymorphic kinds, and so we could always assume that
    the kind of a type was a fresh metavariable. Not so anymore, thus the
    need for two algorithms.

    For HsType forms that can never be kind-polymorphic, we implement only the
    "down" direction, where we safely assume a metavariable kind. For HsType forms
    that *can* be kind-polymorphic, we implement just the "up" (functions with
    "infer" in their name) version, as we gain nothing by also implementing the
    "down" version.

    Note [Future-proofing the type checker]
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    As discussed in Note [Bidirectional type checking], each HsType form is
    handled in *either* tc_infer_hs_type *or* tc_hs_type. These functions
    are mutually recursive, so that either one can work for any type former.
    But, we want to make sure that our pattern-matches are complete. So,
    we have a bunch of repetitive code just so that we get warnings if we're
    missing any patterns.

    -}

    ------------------------------------------
    -- | Check and desugar a type, returning the core type and its
    -- possibly-polymorphic kind. Much like 'tcInferRho' at the expression
    -- level.
    tc_infer_lhs_type :: TcTyMode -> LHsType GhcRn -> TcM (TcType, TcKind)
    tc_infer_lhs_type :: TcTyMode -> LHsType GhcRn -> TcM (Type, Type)
    tc_infer_lhs_type TcTyMode
    mode (L SrcSpanAnnA
    span HsType GhcRn
    ty)
      = SrcSpanAnnA -> TcM (Type, Type) -> TcM (Type, Type)
    forall ann a. SrcSpanAnn' ann -> TcRn a -> TcRn a
    setSrcSpanA SrcSpanAnnA
    span (TcM (Type, Type) -> TcM (Type, Type))
    -> TcM (Type, Type) -> TcM (Type, Type)
    forall a b. (a -> b) -> a -> b
    $
        TcTyMode -> HsType GhcRn -> TcM (Type, Type)
    tc_infer_hs_type TcTyMode
    mode HsType GhcRn
    ty

    ---------------------------
    -- | Call 'tc_infer_hs_type' and check its result against an expected kind.
    tc_infer_hs_type_ek :: HasDebugCallStack => TcTyMode -> HsType GhcRn -> TcKind -> TcM TcType
    tc_infer_hs_type_ek :: HasDebugCallStack => TcTyMode -> HsType GhcRn -> Type -> TcM Type
    tc_infer_hs_type_ek TcTyMode
    mode HsType GhcRn
    hs_ty Type
    ek
      = do { (Type
    ty, Type
    k) <- TcTyMode -> HsType GhcRn -> TcM (Type, Type)
    tc_infer_hs_type TcTyMode
    mode HsType GhcRn
    hs_ty
           ; HasDebugCallStack =>
    HsType GhcRn -> Type -> Type -> Type -> TcM Type
    HsType GhcRn -> Type -> Type -> Type -> TcM Type
    checkExpectedKind HsType GhcRn
    hs_ty Type
    ty Type
    k Type
    ek }

    ---------------------------
    -- | Infer the kind of a type and desugar. This is the "up" type-checker,
    -- as described in Note [Bidirectional type checking]
    tc_infer_hs_type :: TcTyMode -> HsType GhcRn -> TcM (TcType, TcKind)

    tc_infer_hs_type :: TcTyMode -> HsType GhcRn -> TcM (Type, Type)
    tc_infer_hs_type TcTyMode
    mode (HsParTy XParTy GhcRn
    _ LHsType GhcRn
    t)
      = TcTyMode -> LHsType GhcRn -> TcM (Type, Type)
    tc_infer_lhs_type TcTyMode
    mode LHsType GhcRn
    t

    tc_infer_hs_type TcTyMode
    mode HsType GhcRn
    ty
      | Just (LHsType GhcRn
    hs_fun_ty, HsTyPats GhcRn
    hs_args) <- HsType GhcRn -> Maybe (LHsType GhcRn, HsTyPats GhcRn)
    splitHsAppTys HsType GhcRn
    ty
      = do { (Type
    fun_ty, Type
    _ki) <- TcTyMode -> LHsType GhcRn -> TcM (Type, Type)
    tcInferTyAppHead TcTyMode
    mode LHsType GhcRn
    hs_fun_ty
           ; TcTyMode
    -> LHsType GhcRn -> Type -> HsTyPats GhcRn -> TcM (Type, Type)
    tcInferTyApps TcTyMode
    mode LHsType GhcRn
    hs_fun_ty Type
    fun_ty HsTyPats GhcRn
    hs_args }

    tc_infer_hs_type TcTyMode
    mode (HsKindSig XKindSig GhcRn
    _ LHsType GhcRn
    ty LHsType GhcRn
    sig)
      = do { let mode' :: TcTyMode
    mode' = TcTyMode
    mode { mode_tyki :: TypeOrKind
    mode_tyki = TypeOrKind
    KindLevel }
           ; Type
    sig' <- TcTyMode -> UserTypeCtxt -> LHsType GhcRn -> TcM Type
    tc_lhs_kind_sig TcTyMode
    mode' UserTypeCtxt
    KindSigCtxt LHsType GhcRn
    sig
                     -- We must typecheck the kind signature, and solve all
                     -- its equalities etc; from this point on we may do
                     -- things like instantiate its foralls, so it needs
                     -- to be fully determined (#14904)
           ; String -> SDoc -> TcM ()
    traceTc String
    "tc_infer_hs_type:sig" (GenLocated SrcSpanAnnA (HsType GhcRn) -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr GenLocated SrcSpanAnnA (HsType GhcRn)
    LHsType GhcRn
    ty SDoc -> SDoc -> SDoc
    $$ Type -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr Type
    sig')
           ; Type
    ty' <- TcTyMode -> LHsType GhcRn -> Type -> TcM Type
    tc_lhs_type TcTyMode
    mode LHsType GhcRn
    ty Type
    sig'
           ; (Type, Type) -> TcM (Type, Type)
    forall (m :: * -> *) a. Monad m => a -> m a
    return (Type
    ty', Type
    sig') }

    -- HsSpliced is an annotation produced by 'GHC.Rename.Splice.rnSpliceType' to communicate
    -- the splice location to the typechecker. Here we skip over it in order to have
    -- the same kind inferred for a given expression whether it was produced from
    -- splices or not.
    --
    -- See Note [Delaying modFinalizers in untyped splices].
    tc_infer_hs_type TcTyMode
    mode (HsSpliceTy XSpliceTy GhcRn
    _ (HsSpliced XSpliced GhcRn
    _ ThModFinalizers
    _ (HsSplicedTy HsType GhcRn
    ty)))
      = TcTyMode -> HsType GhcRn -> TcM (Type, Type)
    tc_infer_hs_type TcTyMode
    mode HsType GhcRn
    ty

    tc_infer_hs_type TcTyMode
    mode (HsDocTy XDocTy GhcRn
    _ LHsType GhcRn
    ty LHsDocString
    _) = TcTyMode -> LHsType GhcRn -> TcM (Type, Type)
    tc_infer_lhs_type TcTyMode
    mode LHsType GhcRn
    ty

    -- See Note [Typechecking HsCoreTys]
    tc_infer_hs_type TcTyMode
    _ (XHsType XXType GhcRn
    ty)
      = do TcLclEnv
    env <- TcRnIf TcGblEnv TcLclEnv TcLclEnv
    forall gbl lcl. TcRnIf gbl lcl lcl
    getLclEnv
           -- Raw uniques since we go from NameEnv to TvSubstEnv.
           let subst_prs :: [(Unique, TcTyVar)]
               subst_prs :: [(Unique, TyVar)]
    subst_prs = [ (Name -> Unique
    forall a. Uniquable a => a -> Unique
    getUnique Name
    nm, TyVar
    tv)
                           | ATyVar Name
    nm TyVar
    tv <- NameEnv TcTyThing -> [TcTyThing]
    forall a. NameEnv a -> [a]
    nameEnvElts (TcLclEnv -> NameEnv TcTyThing
    tcl_env TcLclEnv
    env) ]
               subst :: TCvSubst
    subst = InScopeSet -> TvSubstEnv -> TCvSubst
    mkTvSubst
                         (VarSet -> InScopeSet
    mkInScopeSet (VarSet -> InScopeSet) -> VarSet -> InScopeSet
    forall a b. (a -> b) -> a -> b
    $ [TyVar] -> VarSet
    mkVarSet ([TyVar] -> VarSet) -> [TyVar] -> VarSet
    forall a b. (a -> b) -> a -> b
    $ ((Unique, TyVar) -> TyVar) -> [(Unique, TyVar)] -> [TyVar]
    forall a b. (a -> b) -> [a] -> [b]
    map (Unique, TyVar) -> TyVar
    forall a b. (a, b) -> b
    snd [(Unique, TyVar)]
    subst_prs)
                         ([(Unique, Type)] -> TvSubstEnv
    forall elt key. [(Unique, elt)] -> UniqFM key elt
    listToUFM_Directly ([(Unique, Type)] -> TvSubstEnv) -> [(Unique, Type)] -> TvSubstEnv
    forall a b. (a -> b) -> a -> b
    $ ((Unique, TyVar) -> (Unique, Type))
    -> [(Unique, TyVar)] -> [(Unique, Type)]
    forall a b. (a -> b) -> [a] -> [b]
    map ((TyVar -> Type) -> (Unique, TyVar) -> (Unique, Type)
    forall a b c. (a -> b) -> (c, a) -> (c, b)
    liftSnd TyVar -> Type
    mkTyVarTy) [(Unique, TyVar)]
    subst_prs)
               ty' :: Type
    ty' = HasCallStack => TCvSubst -> Type -> Type
    TCvSubst -> Type -> Type
    substTy TCvSubst
    subst Type
    XXType GhcRn
    ty
           (Type, Type) -> TcM (Type, Type)
    forall (m :: * -> *) a. Monad m => a -> m a
    return (Type
    ty', HasDebugCallStack => Type -> Type
    Type -> Type
    tcTypeKind Type
    ty')

    tc_infer_hs_type TcTyMode
    _ (HsExplicitListTy XExplicitListTy GhcRn
    _ PromotionFlag
    _ [LHsType GhcRn]
    tys)
      | [GenLocated SrcSpanAnnA (HsType GhcRn)] -> Bool
    forall (t :: * -> *) a. Foldable t => t a -> Bool
    null [GenLocated SrcSpanAnnA (HsType GhcRn)]
    [LHsType GhcRn]
    tys  -- this is so that we can use visible kind application with '[]
                  -- e.g ... '[] @Bool
      = (Type, Type) -> TcM (Type, Type)
    forall (m :: * -> *) a. Monad m => a -> m a
    return (TyCon -> Type
    mkTyConTy TyCon
    promotedNilDataCon,
                [TyVar] -> Type -> Type
    mkSpecForAllTys [TyVar
    alphaTyVar] (Type -> Type) -> Type -> Type
    forall a b. (a -> b) -> a -> b
    $ Type -> Type
    mkListTy Type
    alphaTy)

    tc_infer_hs_type TcTyMode
    mode HsType GhcRn
    other_ty
      = do { Type
    kv <- TcM Type
    newMetaKindVar
           ; Type
    ty' <- TcTyMode -> HsType GhcRn -> Type -> TcM Type
    tc_hs_type TcTyMode
    mode HsType GhcRn
    other_ty Type
    kv
           ; (Type, Type) -> TcM (Type, Type)
    forall (m :: * -> *) a. Monad m => a -> m a
    return (Type
    ty', Type
    kv) }

    {-
    Note [Typechecking HsCoreTys]
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    HsCoreTy is an escape hatch that allows embedding Core Types in HsTypes.
    As such, there's not much to be done in order to typecheck an HsCoreTy,
    since it's already been typechecked to some extent. There is one thing that
    we must do, however: we must substitute the type variables from the tcl_env.
    To see why, consider GeneralizedNewtypeDeriving, which is one of the main
    clients of HsCoreTy (example adapted from #14579):

      newtype T a = MkT a deriving newtype Eq

    This will produce an InstInfo GhcPs that looks roughly like this:

      instance forall a_1. Eq a_1 => Eq (T a_1) where
        (==) = coerce @(  a_1 ->   a_1 -> Bool) -- The type within @(...) is an HsCoreTy
                      @(T a_1 -> T a_1 -> Bool) -- So is this
                      (==)

    This is then fed into the renamer. Since all of the type variables in this
    InstInfo use Exact RdrNames, the resulting InstInfo GhcRn looks basically
    identical. Things get more interesting when the InstInfo is fed into the
    typechecker, however. GHC will first generate fresh skolems to instantiate
    the instance-bound type variables with. In the example above, we might generate
    the skolem a_2 and use that to instantiate a_1, which extends the local type
    environment (tcl_env) with [a_1 :-> a_2]. This gives us:

      instance forall a_2. Eq a_2 => Eq (T a_2) where ...

    To ensure that the body of this instance is well scoped, every occurrence of
    the `a` type variable should refer to a_2, the new skolem. However, the
    HsCoreTys mention a_1, not a_2. Luckily, the tcl_env provides exactly the
    substitution we need ([a_1 :-> a_2]) to fix up the scoping. We apply this
    substitution to each HsCoreTy and all is well:

      instance forall a_2. Eq a_2 => Eq (T a_2) where
        (==) = coerce @(  a_2 ->   a_2 -> Bool)
                      @(T a_2 -> T a_2 -> Bool)
                      (==)
    -}

    ------------------------------------------
    tcLHsType :: LHsType GhcRn -> TcKind -> TcM TcType
    tcLHsType :: LHsType GhcRn -> Type -> TcM Type
    tcLHsType LHsType GhcRn
    hs_ty Type
    exp_kind
      = TcTyMode -> LHsType GhcRn -> Type -> TcM Type
    tc_lhs_type TcTyMode
    typeLevelMode LHsType GhcRn
    hs_ty Type
    exp_kind

    tc_lhs_type :: TcTyMode -> LHsType GhcRn -> TcKind -> TcM TcType
    tc_lhs_type :: TcTyMode -> LHsType GhcRn -> Type -> TcM Type
    tc_lhs_type TcTyMode
    mode (L SrcSpanAnnA
    span HsType GhcRn
    ty) Type
    exp_kind
      = SrcSpanAnnA -> TcM Type -> TcM Type
    forall ann a. SrcSpanAnn' ann -> TcRn a -> TcRn a
    setSrcSpanA SrcSpanAnnA
    span (TcM Type -> TcM Type) -> TcM Type -> TcM Type
    forall a b. (a -> b) -> a -> b
    $
        TcTyMode -> HsType GhcRn -> Type -> TcM Type
    tc_hs_type TcTyMode
    mode HsType GhcRn
    ty Type
    exp_kind

    tc_hs_type :: TcTyMode -> HsType GhcRn -> TcKind -> TcM TcType
    -- See Note [Bidirectional type checking]

    tc_hs_type :: TcTyMode -> HsType GhcRn -> Type -> TcM Type
    tc_hs_type TcTyMode
    mode (HsParTy XParTy GhcRn
    _ LHsType GhcRn
    ty)   Type
    exp_kind = TcTyMode -> LHsType GhcRn -> Type -> TcM Type
    tc_lhs_type TcTyMode
    mode LHsType GhcRn
    ty Type
    exp_kind
    tc_hs_type TcTyMode
    mode (HsDocTy XDocTy GhcRn
    _ LHsType GhcRn
    ty LHsDocString
    _) Type
    exp_kind = TcTyMode -> LHsType GhcRn -> Type -> TcM Type
    tc_lhs_type TcTyMode
    mode LHsType GhcRn
    ty Type
    exp_kind
    tc_hs_type TcTyMode
    _ ty :: HsType GhcRn
    ty@(HsBangTy XBangTy GhcRn
    _ HsSrcBang
    bang LHsType GhcRn
    _) Type
    _
        -- While top-level bangs at this point are eliminated (eg !(Maybe Int)),
        -- other kinds of bangs are not (eg ((!Maybe) Int)). These kinds of
        -- bangs are invalid, so fail. (#7210, #14761)
        = do { let bangError :: String -> TcM Type
    bangError String
    err = SDoc -> TcM Type
    forall a. SDoc -> TcM a
    failWith (SDoc -> TcM Type) -> SDoc -> TcM Type
    forall a b. (a -> b) -> a -> b
    $
                     String -> SDoc
    text String
    "Unexpected" SDoc -> SDoc -> SDoc
    <+> String -> SDoc
    text String
    err SDoc -> SDoc -> SDoc
    <+> String -> SDoc
    text String
    "annotation:" SDoc -> SDoc -> SDoc
    <+> HsType GhcRn -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr HsType GhcRn
    ty SDoc -> SDoc -> SDoc
    $$
                     String -> SDoc
    text String
    err SDoc -> SDoc -> SDoc
    <+> String -> SDoc
    text String
    "annotation cannot appear nested inside a type"
             ; case HsSrcBang
    bang of
                 HsSrcBang SourceText
    _ SrcUnpackedness
    SrcUnpack SrcStrictness
    _           -> String -> TcM Type
    bangError String
    "UNPACK"
                 HsSrcBang SourceText
    _ SrcUnpackedness
    SrcNoUnpack SrcStrictness
    _         -> String -> TcM Type
    bangError String
    "NOUNPACK"
                 HsSrcBang SourceText
    _ SrcUnpackedness
    NoSrcUnpack SrcStrictness
    SrcLazy   -> String -> TcM Type
    bangError String
    "laziness"
                 HsSrcBang SourceText
    _ SrcUnpackedness
    _ SrcStrictness
    _                   -> String -> TcM Type
    bangError String
    "strictness" }
    tc_hs_type TcTyMode
    _ ty :: HsType GhcRn
    ty@(HsRecTy {})      Type
    _
          -- Record types (which only show up temporarily in constructor
          -- signatures) should have been removed by now
        = SDoc -> TcM Type
    forall a. SDoc -> TcM a
    failWithTc (String -> SDoc
    text String
    "Record syntax is illegal here:" SDoc -> SDoc -> SDoc
    <+> HsType GhcRn -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr HsType GhcRn
    ty)

    -- HsSpliced is an annotation produced by 'GHC.Rename.Splice.rnSpliceType'.
    -- Here we get rid of it and add the finalizers to the global environment
    -- while capturing the local environment.
    --
    -- See Note [Delaying modFinalizers in untyped splices].
    tc_hs_type TcTyMode
    mode (HsSpliceTy XSpliceTy GhcRn
    _ (HsSpliced XSpliced GhcRn
    _ ThModFinalizers
    mod_finalizers (HsSplicedTy HsType GhcRn
    ty)))
               Type
    exp_kind
      = do ThModFinalizers -> TcM ()
    addModFinalizersWithLclEnv ThModFinalizers
    mod_finalizers
           TcTyMode -> HsType GhcRn -> Type -> TcM Type
    tc_hs_type TcTyMode
    mode HsType GhcRn
    ty Type
    exp_kind

    -- This should never happen; type splices are expanded by the renamer
    tc_hs_type TcTyMode
    _ ty :: HsType GhcRn
    ty@(HsSpliceTy {}) Type
    _exp_kind
      = SDoc -> TcM Type
    forall a. SDoc -> TcM a
    failWithTc (String -> SDoc
    text String
    "Unexpected type splice:" SDoc -> SDoc -> SDoc
    <+> HsType GhcRn -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr HsType GhcRn
    ty)

    ---------- Functions and applications
    tc_hs_type TcTyMode
    mode (HsFunTy XFunTy GhcRn
    _ HsArrow GhcRn
    mult LHsType GhcRn
    ty1 LHsType GhcRn
    ty2) Type
    exp_kind
      = TcTyMode
    -> HsArrow GhcRn
    -> LHsType GhcRn
    -> LHsType GhcRn
    -> Type
    -> TcM Type
    tc_fun_type TcTyMode
    mode HsArrow GhcRn
    mult LHsType GhcRn
    ty1 LHsType GhcRn
    ty2 Type
    exp_kind

    tc_hs_type TcTyMode
    mode (HsOpTy XOpTy GhcRn
    _ LHsType GhcRn
    ty1 (L SrcSpanAnnN
    _ Name
    op) LHsType GhcRn
    ty2) Type
    exp_kind
      | Name
    op Name -> Unique -> Bool
    forall a. Uniquable a => a -> Unique -> Bool
    `hasKey` Unique
    funTyConKey
      = TcTyMode
    -> HsArrow GhcRn
    -> LHsType GhcRn
    -> LHsType GhcRn
    -> Type
    -> TcM Type
    tc_fun_type TcTyMode
    mode (IsUnicodeSyntax -> HsArrow GhcRn
    forall pass. IsUnicodeSyntax -> HsArrow pass
    HsUnrestrictedArrow IsUnicodeSyntax
    NormalSyntax) LHsType GhcRn
    ty1 LHsType GhcRn
    ty2 Type
    exp_kind

    --------- Foralls
    tc_hs_type TcTyMode
    mode (HsForAllTy { hst_tele :: forall pass. HsType pass -> HsForAllTelescope pass
    hst_tele = HsForAllTelescope GhcRn
    tele, hst_body :: forall pass. HsType pass -> LHsType pass
    hst_body = LHsType GhcRn
    ty }) Type
    exp_kind
      = do { ([TcTyVarBinder]
    tv_bndrs, Type
    ty') <- TcTyMode
    -> HsForAllTelescope GhcRn
    -> TcM Type
    -> TcM ([TcTyVarBinder], Type)
    forall a.
    TcTyMode
    -> HsForAllTelescope GhcRn -> TcM a -> TcM ([TcTyVarBinder], a)
    tcTKTelescope TcTyMode
    mode HsForAllTelescope GhcRn
    tele (TcM Type -> TcM ([TcTyVarBinder], Type))
    -> TcM Type -> TcM ([TcTyVarBinder], Type)
    forall a b. (a -> b) -> a -> b
    $
                                TcTyMode -> LHsType GhcRn -> Type -> TcM Type
    tc_lhs_type TcTyMode
    mode LHsType GhcRn
    ty Type
    exp_kind
                     -- Pass on the mode from the type, to any wildcards
                     -- in kind signatures on the forall'd variables
                     -- e.g.      f :: _ -> Int -> forall (a :: _). blah
                     -- Why exp_kind?  See Note [Body kind of HsForAllTy]

           -- Do not kind-generalise here!  See Note [Kind generalisation]

           ; Type -> TcM Type
    forall (m :: * -> *) a. Monad m => a -> m a
    return ([TcTyVarBinder] -> Type -> Type
    mkForAllTys [TcTyVarBinder]
    tv_bndrs Type
    ty') }

    tc_hs_type TcTyMode
    mode (HsQualTy { hst_ctxt :: forall pass. HsType pass -> Maybe (LHsContext pass)
    hst_ctxt = Maybe (LHsContext GhcRn)
    ctxt, hst_body :: forall pass. HsType pass -> LHsType pass
    hst_body = LHsType GhcRn
    rn_ty }) Type
    exp_kind
      | [GenLocated SrcSpanAnnA (HsType GhcRn)] -> Bool
    forall (t :: * -> *) a. Foldable t => t a -> Bool
    null (Maybe (LHsContext GhcRn) -> [LHsType GhcRn]
    forall (p :: Pass).
    Maybe (LHsContext (GhcPass p)) -> HsContext (GhcPass p)
    fromMaybeContext Maybe (LHsContext GhcRn)
    ctxt)
      = TcTyMode -> LHsType GhcRn -> Type -> TcM Type
    tc_lhs_type TcTyMode
    mode LHsType GhcRn
    rn_ty Type
    exp_kind

      -- See Note [Body kind of a HsQualTy]
      | Type -> Bool
    tcIsConstraintKind Type
    exp_kind
      = do { [Type]
    ctxt' <- TcTyMode -> Maybe (LHsContext GhcRn) -> TcM [Type]
    tc_hs_context TcTyMode
    mode Maybe (LHsContext GhcRn)
    ctxt
           ; Type
    ty'   <- TcTyMode -> LHsType GhcRn -> Type -> TcM Type
    tc_lhs_type TcTyMode
    mode LHsType GhcRn
    rn_ty Type
    constraintKind
           ; Type -> TcM Type
    forall (m :: * -> *) a. Monad m => a -> m a
    return ([Type] -> Type -> Type
    mkPhiTy [Type]
    ctxt' Type
    ty') }

      | Bool
    otherwise
      = do { [Type]
    ctxt' <- TcTyMode -> Maybe (LHsContext GhcRn) -> TcM [Type]
    tc_hs_context TcTyMode
    mode Maybe (LHsContext GhcRn)
    ctxt

           ; Type
    ek <- TcM Type
    newOpenTypeKind  -- The body kind (result of the function) can
                                    -- be TYPE r, for any r, hence newOpenTypeKind
           ; Type
    ty' <- TcTyMode -> LHsType GhcRn -> Type -> TcM Type
    tc_lhs_type TcTyMode
    mode LHsType GhcRn
    rn_ty Type
    ek
           ; HasDebugCallStack =>
    HsType GhcRn -> Type -> Type -> Type -> TcM Type
    HsType GhcRn -> Type -> Type -> Type -> TcM Type
    checkExpectedKind (GenLocated SrcSpanAnnA (HsType GhcRn) -> HsType GhcRn
    forall l e. GenLocated l e -> e
    unLoc GenLocated SrcSpanAnnA (HsType GhcRn)
    LHsType GhcRn
    rn_ty) ([Type] -> Type -> Type
    mkPhiTy [Type]
    ctxt' Type
    ty')
                               Type
    liftedTypeKind Type
    exp_kind }

    --------- Lists, arrays, and tuples
    tc_hs_type TcTyMode
    mode rn_ty :: HsType GhcRn
    rn_ty@(HsListTy XListTy GhcRn
    _ LHsType GhcRn
    elt_ty) Type
    exp_kind
      = do { Type
    tau_ty <- TcTyMode -> LHsType GhcRn -> Type -> TcM Type
    tc_lhs_type TcTyMode
    mode LHsType GhcRn
    elt_ty Type
    liftedTypeKind
           ; TyCon -> TcM ()
    checkWiredInTyCon TyCon
    listTyCon
           ; HasDebugCallStack =>
    HsType GhcRn -> Type -> Type -> Type -> TcM Type
    HsType GhcRn -> Type -> Type -> Type -> TcM Type
    checkExpectedKind HsType GhcRn
    rn_ty (Type -> Type
    mkListTy Type
    tau_ty) Type
    liftedTypeKind Type
    exp_kind }

    -- See Note [Distinguishing tuple kinds] in GHC.Hs.Type
    -- See Note [Inferring tuple kinds]
    tc_hs_type TcTyMode
    mode rn_ty :: HsType GhcRn
    rn_ty@(HsTupleTy XTupleTy GhcRn
    _ HsTupleSort
    HsBoxedOrConstraintTuple [LHsType GhcRn]
    hs_tys) Type
    exp_kind
         -- (NB: not zonking before looking at exp_k, to avoid left-right bias)
      | Just TupleSort
    tup_sort <- Type -> Maybe TupleSort
    tupKindSort_maybe Type
    exp_kind
      = String -> SDoc -> TcM ()
    traceTc String
    "tc_hs_type tuple" ([GenLocated SrcSpanAnnA (HsType GhcRn)] -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr [GenLocated SrcSpanAnnA (HsType GhcRn)]
    [LHsType GhcRn]
    hs_tys) TcM () -> TcM Type -> TcM Type
    forall (m :: * -> *) a b. Monad m => m a -> m b -> m b
    >>
        HsType GhcRn
    -> TcTyMode -> TupleSort -> [LHsType GhcRn] -> Type -> TcM Type
    tc_tuple HsType GhcRn
    rn_ty TcTyMode
    mode TupleSort
    tup_sort [LHsType GhcRn]
    hs_tys Type
    exp_kind
      | Bool
    otherwise
      = do { String -> SDoc -> TcM ()
    traceTc String
    "tc_hs_type tuple 2" ([GenLocated SrcSpanAnnA (HsType GhcRn)] -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr [GenLocated SrcSpanAnnA (HsType GhcRn)]
    [LHsType GhcRn]
    hs_tys)
           ; ([Type]
    tys, [Type]
    kinds) <- (GenLocated SrcSpanAnnA (HsType GhcRn) -> TcM (Type, Type))
    -> [GenLocated SrcSpanAnnA (HsType GhcRn)]
    -> IOEnv (Env TcGblEnv TcLclEnv) ([Type], [Type])
    forall (m :: * -> *) a b c.
    Applicative m =>
    (a -> m (b, c)) -> [a] -> m ([b], [c])
    mapAndUnzipM (TcTyMode -> LHsType GhcRn -> TcM (Type, Type)
    tc_infer_lhs_type TcTyMode
    mode) [GenLocated SrcSpanAnnA (HsType GhcRn)]
    [LHsType GhcRn]
    hs_tys
           ; [Type]
    kinds <- (Type -> TcM Type) -> [Type] -> TcM [Type]
    forall (t :: * -> *) (m :: * -> *) a b.
    (Traversable t, Monad m) =>
    (a -> m b) -> t a -> m (t b)
    mapM Type -> TcM Type
    zonkTcType [Type]
    kinds
               -- Infer each arg type separately, because errors can be
               -- confusing if we give them a shared kind.  Eg #7410
               -- (Either Int, Int), we do not want to get an error saying
               -- "the second argument of a tuple should have kind *->*"

           ; let (Type
    arg_kind, TupleSort
    tup_sort)
                   = case [ (Type
    k,TupleSort
    s) | Type
    k <- [Type]
    kinds
                                  , Just TupleSort
    s <- [Type -> Maybe TupleSort
    tupKindSort_maybe Type
    k] ] of
                        ((Type
    k,TupleSort
    s) : [(Type, TupleSort)]
    _) -> (Type
    k,TupleSort
    s)
                        [] -> (Type
    liftedTypeKind, TupleSort
    BoxedTuple)
             -- In the [] case, it's not clear what the kind is, so guess *

           ; [Type]
    tys' <- [TcM Type] -> TcM [Type]
    forall (t :: * -> *) (m :: * -> *) a.
    (Traversable t, Monad m) =>
    t (m a) -> m (t a)
    sequence [ SrcSpanAnnA -> TcM Type -> TcM Type
    forall ann a. SrcSpanAnn' ann -> TcRn a -> TcRn a
    setSrcSpanA SrcSpanAnnA
    loc (TcM Type -> TcM Type) -> TcM Type -> TcM Type
    forall a b. (a -> b) -> a -> b
    $
                                HasDebugCallStack =>
    HsType GhcRn -> Type -> Type -> Type -> TcM Type
    HsType GhcRn -> Type -> Type -> Type -> TcM Type
    checkExpectedKind HsType GhcRn
    hs_ty Type
    ty Type
    kind Type
    arg_kind
                              | ((L SrcSpanAnnA
    loc HsType GhcRn
    hs_ty),Type
    ty,Type
    kind) <- [GenLocated SrcSpanAnnA (HsType GhcRn)]
    -> [Type]
    -> [Type]
    -> [(GenLocated SrcSpanAnnA (HsType GhcRn), Type, Type)]
    forall a b c. [a] -> [b] -> [c] -> [(a, b, c)]
    zip3 [GenLocated SrcSpanAnnA (HsType GhcRn)]
    [LHsType GhcRn]
    hs_tys [Type]
    tys [Type]
    kinds ]

           ; HsType GhcRn -> TupleSort -> [Type] -> [Type] -> Type -> TcM Type
    finish_tuple HsType GhcRn
    rn_ty TupleSort
    tup_sort [Type]
    tys' ((Type -> Type) -> [Type] -> [Type]
    forall a b. (a -> b) -> [a] -> [b]
    map (Type -> Type -> Type
    forall a b. a -> b -> a
    const Type
    arg_kind) [Type]
    tys') Type
    exp_kind }

    tc_hs_type TcTyMode
    mode rn_ty :: HsType GhcRn
    rn_ty@(HsTupleTy XTupleTy GhcRn
    _ HsTupleSort
    HsUnboxedTuple [LHsType GhcRn]
    tys) Type
    exp_kind
      = HsType GhcRn
    -> TcTyMode -> TupleSort -> [LHsType GhcRn] -> Type -> TcM Type
    tc_tuple HsType GhcRn
    rn_ty TcTyMode
    mode TupleSort
    UnboxedTuple [LHsType GhcRn]
    tys Type
    exp_kind

    tc_hs_type TcTyMode
    mode rn_ty :: HsType GhcRn
    rn_ty@(HsSumTy XSumTy GhcRn
    _ [LHsType GhcRn]
    hs_tys) Type
    exp_kind
      = do { let arity :: Arity
    arity = [GenLocated SrcSpanAnnA (HsType GhcRn)] -> Arity
    forall (t :: * -> *) a. Foldable t => t a -> Arity
    length [GenLocated SrcSpanAnnA (HsType GhcRn)]
    [LHsType GhcRn]
    hs_tys
           ; [Type]
    arg_kinds <- (GenLocated SrcSpanAnnA (HsType GhcRn) -> TcM Type)
    -> [GenLocated SrcSpanAnnA (HsType GhcRn)] -> TcM [Type]
    forall (t :: * -> *) (m :: * -> *) a b.
    (Traversable t, Monad m) =>
    (a -> m b) -> t a -> m (t b)
    mapM (\GenLocated SrcSpanAnnA (HsType GhcRn)
    _ -> TcM Type
    newOpenTypeKind) [GenLocated SrcSpanAnnA (HsType GhcRn)]
    [LHsType GhcRn]
    hs_tys
           ; [Type]
    tau_tys   <- (GenLocated SrcSpanAnnA (HsType GhcRn) -> Type -> TcM Type)
    -> [GenLocated SrcSpanAnnA (HsType GhcRn)] -> [Type] -> TcM [Type]
    forall (m :: * -> *) a b c.
    Applicative m =>
    (a -> b -> m c) -> [a] -> [b] -> m [c]
    zipWithM (TcTyMode -> LHsType GhcRn -> Type -> TcM Type
    tc_lhs_type TcTyMode
    mode) [GenLocated SrcSpanAnnA (HsType GhcRn)]
    [LHsType GhcRn]
    hs_tys [Type]
    arg_kinds
           ; let arg_reps :: [Type]
    arg_reps = (Type -> Type) -> [Type] -> [Type]
    forall a b. (a -> b) -> [a] -> [b]
    map HasDebugCallStack => Type -> Type
    Type -> Type
    kindRep [Type]
    arg_kinds
                 arg_tys :: [Type]
    arg_tys  = [Type]
    arg_reps [Type] -> [Type] -> [Type]
    forall a. [a] -> [a] -> [a]
    ++ [Type]
    tau_tys
                 sum_ty :: Type
    sum_ty   = TyCon -> [Type] -> Type
    mkTyConApp (Arity -> TyCon
    sumTyCon Arity
    arity) [Type]
    arg_tys
                 sum_kind :: Type
    sum_kind = [Type] -> Type
    unboxedSumKind [Type]
    arg_reps
           ; HasDebugCallStack =>
    HsType GhcRn -> Type -> Type -> Type -> TcM Type
    HsType GhcRn -> Type -> Type -> Type -> TcM Type
    checkExpectedKind HsType GhcRn
    rn_ty Type
    sum_ty Type
    sum_kind Type
    exp_kind
           }

    --------- Promoted lists and tuples
    tc_hs_type TcTyMode
    mode rn_ty :: HsType GhcRn
    rn_ty@(HsExplicitListTy XExplicitListTy GhcRn
    _ PromotionFlag
    _ [LHsType GhcRn]
    tys) Type
    exp_kind
      = do { [(Type, Type)]
    tks <- (GenLocated SrcSpanAnnA (HsType GhcRn) -> TcM (Type, Type))
    -> [GenLocated SrcSpanAnnA (HsType GhcRn)]
    -> IOEnv (Env TcGblEnv TcLclEnv) [(Type, Type)]
    forall (t :: * -> *) (m :: * -> *) a b.
    (Traversable t, Monad m) =>
    (a -> m b) -> t a -> m (t b)
    mapM (TcTyMode -> LHsType GhcRn -> TcM (Type, Type)
    tc_infer_lhs_type TcTyMode
    mode) [GenLocated SrcSpanAnnA (HsType GhcRn)]
    [LHsType GhcRn]
    tys
           ; ([Type]
    taus', Type
    kind) <- [LHsType GhcRn] -> [(Type, Type)] -> TcM ([Type], Type)
    unifyKinds [LHsType GhcRn]
    tys [(Type, Type)]
    tks
           ; let ty :: Type
    ty = ((Type -> Type -> Type) -> Type -> [Type] -> Type
    forall (t :: * -> *) a b.
    Foldable t =>
    (a -> b -> b) -> b -> t a -> b
    foldr (Type -> Type -> Type -> Type
    mk_cons Type
    kind) (Type -> Type
    mk_nil Type
    kind) [Type]
    taus')
           ; HasDebugCallStack =>
    HsType GhcRn -> Type -> Type -> Type -> TcM Type
    HsType GhcRn -> Type -> Type -> Type -> TcM Type
    checkExpectedKind HsType GhcRn
    rn_ty Type
    ty (Type -> Type
    mkListTy Type
    kind) Type
    exp_kind }
      where
        mk_cons :: Type -> Type -> Type -> Type
    mk_cons Type
    k Type
    a Type
    b = TyCon -> [Type] -> Type
    mkTyConApp (DataCon -> TyCon
    promoteDataCon DataCon
    consDataCon) [Type
    k, Type
    a, Type
    b]
        mk_nil :: Type -> Type
    mk_nil  Type
    k     = TyCon -> [Type] -> Type
    mkTyConApp (DataCon -> TyCon
    promoteDataCon DataCon
    nilDataCon) [Type
    k]

    tc_hs_type TcTyMode
    mode rn_ty :: HsType GhcRn
    rn_ty@(HsExplicitTupleTy XExplicitTupleTy GhcRn
    _ [LHsType GhcRn]
    tys) Type
    exp_kind
      -- using newMetaKindVar means that we force instantiations of any polykinded
      -- types. At first, I just used tc_infer_lhs_type, but that led to #11255.
      = do { [Type]
    ks   <- Arity -> TcM Type -> TcM [Type]
    forall (m :: * -> *) a. Applicative m => Arity -> m a -> m [a]
    replicateM Arity
    arity TcM Type
    newMetaKindVar
           ; [Type]
    taus <- (GenLocated SrcSpanAnnA (HsType GhcRn) -> Type -> TcM Type)
    -> [GenLocated SrcSpanAnnA (HsType GhcRn)] -> [Type] -> TcM [Type]
    forall (m :: * -> *) a b c.
    Applicative m =>
    (a -> b -> m c) -> [a] -> [b] -> m [c]
    zipWithM (TcTyMode -> LHsType GhcRn -> Type -> TcM Type
    tc_lhs_type TcTyMode
    mode) [GenLocated SrcSpanAnnA (HsType GhcRn)]
    [LHsType GhcRn]
    tys [Type]
    ks
           ; let kind_con :: TyCon
    kind_con   = Boxity -> Arity -> TyCon
    tupleTyCon           Boxity
    Boxed Arity
    arity
                 ty_con :: TyCon
    ty_con     = Boxity -> Arity -> TyCon
    promotedTupleDataCon Boxity
    Boxed Arity
    arity
                 tup_k :: Type
    tup_k      = TyCon -> [Type] -> Type
    mkTyConApp TyCon
    kind_con [Type]
    ks
           ; Arity -> TcM ()
    checkTupSize Arity
    arity
           ; HasDebugCallStack =>
    HsType GhcRn -> Type -> Type -> Type -> TcM Type
    HsType GhcRn -> Type -> Type -> Type -> TcM Type
    checkExpectedKind HsType GhcRn
    rn_ty (TyCon -> [Type] -> Type
    mkTyConApp TyCon
    ty_con ([Type]
    ks [Type] -> [Type] -> [Type]
    forall a. [a] -> [a] -> [a]
    ++ [Type]
    taus)) Type
    tup_k Type
    exp_kind }
      where
        arity :: Arity
    arity = [GenLocated SrcSpanAnnA (HsType GhcRn)] -> Arity
    forall (t :: * -> *) a. Foldable t => t a -> Arity
    length [GenLocated SrcSpanAnnA (HsType GhcRn)]
    [LHsType GhcRn]
    tys

    --------- Constraint types
    tc_hs_type TcTyMode
    mode rn_ty :: HsType GhcRn
    rn_ty@(HsIParamTy XIParamTy GhcRn
    _ (L SrcSpan
    _ HsIPName
    n) LHsType GhcRn
    ty) Type
    exp_kind
      = do { MASSERT( isTypeLevel (mode_tyki mode) )
           ; Type
    ty' <- TcTyMode -> LHsType GhcRn -> Type -> TcM Type
    tc_lhs_type TcTyMode
    mode LHsType GhcRn
    ty Type
    liftedTypeKind
           ; let n' :: Type
    n' = FastString -> Type
    mkStrLitTy (FastString -> Type) -> FastString -> Type
    forall a b. (a -> b) -> a -> b
    $ HsIPName -> FastString
    hsIPNameFS HsIPName
    n
           ; Class
    ipClass <- Name -> TcM Class
    tcLookupClass Name
    ipClassName
           ; HasDebugCallStack =>
    HsType GhcRn -> Type -> Type -> Type -> TcM Type
    HsType GhcRn -> Type -> Type -> Type -> TcM Type
    checkExpectedKind HsType GhcRn
    rn_ty (Class -> [Type] -> Type
    mkClassPred Class
    ipClass [Type
    n',Type
    ty'])
                               Type
    constraintKind Type
    exp_kind }

    tc_hs_type TcTyMode
    _ rn_ty :: HsType GhcRn
    rn_ty@(HsStarTy XStarTy GhcRn
    _ Bool
    _) Type
    exp_kind
      -- Desugaring 'HsStarTy' to 'Data.Kind.Type' here means that we don't have to
      -- handle it in 'coreView' and 'tcView'.
      = HasDebugCallStack =>
    HsType GhcRn -> Type -> Type -> Type -> TcM Type
    HsType GhcRn -> Type -> Type -> Type -> TcM Type
    checkExpectedKind HsType GhcRn
    rn_ty Type
    liftedTypeKind Type
    liftedTypeKind Type
    exp_kind

    --------- Literals
    tc_hs_type TcTyMode
    _ rn_ty :: HsType GhcRn
    rn_ty@(HsTyLit XTyLit GhcRn
    _ (HsNumTy SourceText
    _ Integer
    n)) Type
    exp_kind
      = do { TyCon -> TcM ()
    checkWiredInTyCon TyCon
    naturalTyCon
           ; HasDebugCallStack =>
    HsType GhcRn -> Type -> Type -> Type -> TcM Type
    HsType GhcRn -> Type -> Type -> Type -> TcM Type
    checkExpectedKind HsType GhcRn
    rn_ty (Integer -> Type
    mkNumLitTy Integer
    n) Type
    naturalTy Type
    exp_kind }

    tc_hs_type TcTyMode
    _ rn_ty :: HsType GhcRn
    rn_ty@(HsTyLit XTyLit GhcRn
    _ (HsStrTy SourceText
    _ FastString
    s)) Type
    exp_kind
      = do { TyCon -> TcM ()
    checkWiredInTyCon TyCon
    typeSymbolKindCon
           ; HasDebugCallStack =>
    HsType GhcRn -> Type -> Type -> Type -> TcM Type
    HsType GhcRn -> Type -> Type -> Type -> TcM Type
    checkExpectedKind HsType GhcRn
    rn_ty (FastString -> Type
    mkStrLitTy FastString
    s) Type
    typeSymbolKind Type
    exp_kind }
    tc_hs_type TcTyMode
    _ rn_ty :: HsType GhcRn
    rn_ty@(HsTyLit XTyLit GhcRn
    _ (HsCharTy SourceText
    _ Char
    c)) Type
    exp_kind
      = do { TyCon -> TcM ()
    checkWiredInTyCon TyCon
    charTyCon
           ; HasDebugCallStack =>
    HsType GhcRn -> Type -> Type -> Type -> TcM Type
    HsType GhcRn -> Type -> Type -> Type -> TcM Type
    checkExpectedKind HsType GhcRn
    rn_ty (Char -> Type
    mkCharLitTy Char
    c) Type
    charTy Type
    exp_kind }

    --------- Wildcards

    tc_hs_type TcTyMode
    mode ty :: HsType GhcRn
    ty@(HsWildCardTy XWildCardTy GhcRn
    _)        Type
    ek
      = IsExtraConstraint -> TcTyMode -> HsType GhcRn -> Type -> TcM Type
    tcAnonWildCardOcc IsExtraConstraint
    NoExtraConstraint TcTyMode
    mode HsType GhcRn
    ty Type
    ek

    --------- Potentially kind-polymorphic types: call the "up" checker
    -- See Note [Future-proofing the type checker]
    tc_hs_type TcTyMode
    mode ty :: HsType GhcRn
    ty@(HsTyVar {})            Type
    ek = HasDebugCallStack => TcTyMode -> HsType GhcRn -> Type -> TcM Type
    TcTyMode -> HsType GhcRn -> Type -> TcM Type
    tc_infer_hs_type_ek TcTyMode
    mode HsType GhcRn
    ty Type
    ek
    tc_hs_type TcTyMode
    mode ty :: HsType GhcRn
    ty@(HsAppTy {})            Type
    ek = HasDebugCallStack => TcTyMode -> HsType GhcRn -> Type -> TcM Type
    TcTyMode -> HsType GhcRn -> Type -> TcM Type
    tc_infer_hs_type_ek TcTyMode
    mode HsType GhcRn
    ty Type
    ek
    tc_hs_type TcTyMode
    mode ty :: HsType GhcRn
    ty@(HsAppKindTy{})         Type
    ek = HasDebugCallStack => TcTyMode -> HsType GhcRn -> Type -> TcM Type
    TcTyMode -> HsType GhcRn -> Type -> TcM Type
    tc_infer_hs_type_ek TcTyMode
    mode HsType GhcRn
    ty Type
    ek
    tc_hs_type TcTyMode
    mode ty :: HsType GhcRn
    ty@(HsOpTy {})             Type
    ek = HasDebugCallStack => TcTyMode -> HsType GhcRn -> Type -> TcM Type
    TcTyMode -> HsType GhcRn -> Type -> TcM Type
    tc_infer_hs_type_ek TcTyMode
    mode HsType GhcRn
    ty Type
    ek
    tc_hs_type TcTyMode
    mode ty :: HsType GhcRn
    ty@(HsKindSig {})          Type
    ek = HasDebugCallStack => TcTyMode -> HsType GhcRn -> Type -> TcM Type
    TcTyMode -> HsType GhcRn -> Type -> TcM Type
    tc_infer_hs_type_ek TcTyMode
    mode HsType GhcRn
    ty Type
    ek
    tc_hs_type TcTyMode
    mode ty :: HsType GhcRn
    ty@(XHsType {})            Type
    ek = HasDebugCallStack => TcTyMode -> HsType GhcRn -> Type -> TcM Type
    TcTyMode -> HsType GhcRn -> Type -> TcM Type
    tc_infer_hs_type_ek TcTyMode
    mode HsType GhcRn
    ty Type
    ek

    {-
    Note [Variable Specificity and Forall Visibility]
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    A HsForAllTy contains an HsForAllTelescope to denote the visibility of the forall
    binder. Furthermore, each invisible type variable binder also has a
    Specificity. Together, these determine the variable binders (ArgFlag) for each
    variable in the generated ForAllTy type.

    This table summarises this relation:
    ----------------------------------------------------------------------------
    | User-written type         HsForAllTelescope   Specificity        ArgFlag
    |---------------------------------------------------------------------------
    | f :: forall a. type       HsForAllInvis       SpecifiedSpec      Specified
    | f :: forall {a}. type     HsForAllInvis       InferredSpec       Inferred
    | f :: forall a -> type     HsForAllVis         SpecifiedSpec      Required
    | f :: forall {a} -> type   HsForAllVis         InferredSpec       /
    |   This last form is non-sensical and is thus rejected.
    ----------------------------------------------------------------------------

    For more information regarding the interpretation of the resulting ArgFlag, see
    Note [VarBndrs, TyCoVarBinders, TyConBinders, and visibility] in "GHC.Core.TyCo.Rep".
    -}

    ------------------------------------------
    tc_mult :: TcTyMode -> HsArrow GhcRn -> TcM Mult
    tc_mult :: TcTyMode -> HsArrow GhcRn -> TcM Type
    tc_mult TcTyMode
    mode HsArrow GhcRn
    ty = TcTyMode -> LHsType GhcRn -> Type -> TcM Type
    tc_lhs_type TcTyMode
    mode (HsArrow GhcRn -> LHsType GhcRn
    arrowToHsType HsArrow GhcRn
    ty) Type
    multiplicityTy
    ------------------------------------------
    tc_fun_type :: TcTyMode -> HsArrow GhcRn -> LHsType GhcRn -> LHsType GhcRn -> TcKind
                -> TcM TcType
    tc_fun_type :: TcTyMode
    -> HsArrow GhcRn
    -> LHsType GhcRn
    -> LHsType GhcRn
    -> Type
    -> TcM Type
    tc_fun_type TcTyMode
    mode HsArrow GhcRn
    mult LHsType GhcRn
    ty1 LHsType GhcRn
    ty2 Type
    exp_kind = case TcTyMode -> TypeOrKind
    mode_tyki TcTyMode
    mode of
      TypeOrKind
    TypeLevel ->
        do { Type
    arg_k <- TcM Type
    newOpenTypeKind
           ; Type
    res_k <- TcM Type
    newOpenTypeKind
           ; Type
    ty1' <- TcTyMode -> LHsType GhcRn -> Type -> TcM Type
    tc_lhs_type TcTyMode
    mode LHsType GhcRn
    ty1 Type
    arg_k
           ; Type
    ty2' <- TcTyMode -> LHsType GhcRn -> Type -> TcM Type
    tc_lhs_type TcTyMode
    mode LHsType GhcRn
    ty2 Type
    res_k
           ; Type
    mult' <- TcTyMode -> HsArrow GhcRn -> TcM Type
    tc_mult TcTyMode
    mode HsArrow GhcRn
    mult
           ; HasDebugCallStack =>
    HsType GhcRn -> Type -> Type -> Type -> TcM Type
    HsType GhcRn -> Type -> Type -> Type -> TcM Type
    checkExpectedKind (XFunTy GhcRn
    -> HsArrow GhcRn -> LHsType GhcRn -> LHsType GhcRn -> HsType GhcRn
    forall pass.
    XFunTy pass
    -> HsArrow pass -> LHsType pass -> LHsType pass -> HsType pass
    HsFunTy XFunTy GhcRn
    forall a. EpAnn a
    noAnn HsArrow GhcRn
    mult LHsType GhcRn
    ty1 LHsType GhcRn
    ty2) (Type -> Type -> Type -> Type
    mkVisFunTy Type
    mult' Type
    ty1' Type
    ty2')
                               Type
    liftedTypeKind Type
    exp_kind }
      TypeOrKind
    KindLevel ->  -- no representation polymorphism in kinds. yet.
        do { Type
    ty1' <- TcTyMode -> LHsType GhcRn -> Type -> TcM Type
    tc_lhs_type TcTyMode
    mode LHsType GhcRn
    ty1 Type
    liftedTypeKind
           ; Type
    ty2' <- TcTyMode -> LHsType GhcRn -> Type -> TcM Type
    tc_lhs_type TcTyMode
    mode LHsType GhcRn
    ty2 Type
    liftedTypeKind
           ; Type
    mult' <- TcTyMode -> HsArrow GhcRn -> TcM Type
    tc_mult TcTyMode
    mode HsArrow GhcRn
    mult
           ; HasDebugCallStack =>
    HsType GhcRn -> Type -> Type -> Type -> TcM Type
    HsType GhcRn -> Type -> Type -> Type -> TcM Type
    checkExpectedKind (XFunTy GhcRn
    -> HsArrow GhcRn -> LHsType GhcRn -> LHsType GhcRn -> HsType GhcRn
    forall pass.
    XFunTy pass
    -> HsArrow pass -> LHsType pass -> LHsType pass -> HsType pass
    HsFunTy XFunTy GhcRn
    forall a. EpAnn a
    noAnn HsArrow GhcRn
    mult LHsType GhcRn
    ty1 LHsType GhcRn
    ty2) (Type -> Type -> Type -> Type
    mkVisFunTy Type
    mult' Type
    ty1' Type
    ty2')
                               Type
    liftedTypeKind Type
    exp_kind }

    {- Note [Skolem escape and forall-types]
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    See also Note [Checking telescopes].

    Consider
      f :: forall a. (forall kb (b :: kb). Proxy '[a, b]) -> ()

    The Proxy '[a,b] forces a and b to have the same kind.  But a's
    kind must be bound outside the 'forall a', and hence escapes.
    We discover this by building an implication constraint for
    each forall.  So the inner implication constraint will look like
        forall kb (b::kb).  kb ~ ka
    where ka is a's kind.  We can't unify these two, /even/ if ka is
    unification variable, because it would be untouchable inside
    this inner implication.

    That's what the pushLevelAndCaptureConstraints, plus subsequent
    buildTvImplication/emitImplication is all about, when kind-checking
    HsForAllTy.

    Note that

    * We don't need to /simplify/ the constraints here
      because we aren't generalising. We just capture them.

    * We can't use emitResidualTvConstraint, because that has a fast-path
      for empty constraints.  We can't take that fast path here, because
      we must do the bad-telescope check even if there are no inner wanted
      constraints. See Note [Checking telescopes] in
      GHC.Tc.Types.Constraint.  Lacking this check led to #16247.
    -}

    {- *********************************************************************
    *                                                                      *
                    Tuples
    *                                                                      *
    ********************************************************************* -}

    ---------------------------
    tupKindSort_maybe :: TcKind -> Maybe TupleSort
    tupKindSort_maybe :: Type -> Maybe TupleSort
    tupKindSort_maybe Type
    k
      | Just (Type
    k', Coercion
    _) <- Type -> Maybe (Type, Coercion)
    splitCastTy_maybe Type
    k = Type -> Maybe TupleSort
    tupKindSort_maybe Type
    k'
      | Just Type
    k'      <- Type -> Maybe Type
    tcView Type
    k            = Type -> Maybe TupleSort
    tupKindSort_maybe Type
    k'
      | Type -> Bool
    tcIsConstraintKind Type
    k = TupleSort -> Maybe TupleSort
    forall a. a -> Maybe a
    Just TupleSort
    ConstraintTuple
      | Type -> Bool
    tcIsLiftedTypeKind Type
    k   = TupleSort -> Maybe TupleSort
    forall a. a -> Maybe a
    Just TupleSort
    BoxedTuple
      | Bool
    otherwise            = Maybe TupleSort
    forall a. Maybe a
    Nothing

    tc_tuple :: HsType GhcRn -> TcTyMode -> TupleSort -> [LHsType GhcRn] -> TcKind -> TcM TcType
    tc_tuple :: HsType GhcRn
    -> TcTyMode -> TupleSort -> [LHsType GhcRn] -> Type -> TcM Type
    tc_tuple HsType GhcRn
    rn_ty TcTyMode
    mode TupleSort
    tup_sort [LHsType GhcRn]
    tys Type
    exp_kind
      = do { [Type]
    arg_kinds <- case TupleSort
    tup_sort of
               TupleSort
    BoxedTuple      -> [Type] -> TcM [Type]
    forall (m :: * -> *) a. Monad m => a -> m a
    return (Arity -> Type -> [Type]
    forall a. Arity -> a -> [a]
    replicate Arity
    arity Type
    liftedTypeKind)
               TupleSort
    UnboxedTuple    -> Arity -> TcM Type -> TcM [Type]
    forall (m :: * -> *) a. Applicative m => Arity -> m a -> m [a]
    replicateM Arity
    arity TcM Type
    newOpenTypeKind
               TupleSort
    ConstraintTuple -> [Type] -> TcM [Type]
    forall (m :: * -> *) a. Monad m => a -> m a
    return (Arity -> Type -> [Type]
    forall a. Arity -> a -> [a]
    replicate Arity
    arity Type
    constraintKind)
           ; [Type]
    tau_tys <- (GenLocated SrcSpanAnnA (HsType GhcRn) -> Type -> TcM Type)
    -> [GenLocated SrcSpanAnnA (HsType GhcRn)] -> [Type] -> TcM [Type]
    forall (m :: * -> *) a b c.
    Applicative m =>
    (a -> b -> m c) -> [a] -> [b] -> m [c]
    zipWithM (TcTyMode -> LHsType GhcRn -> Type -> TcM Type
    tc_lhs_type TcTyMode
    mode) [GenLocated SrcSpanAnnA (HsType GhcRn)]
    [LHsType GhcRn]
    tys [Type]
    arg_kinds
           ; HsType GhcRn -> TupleSort -> [Type] -> [Type] -> Type -> TcM Type
    finish_tuple HsType GhcRn
    rn_ty TupleSort
    tup_sort [Type]
    tau_tys [Type]
    arg_kinds Type
    exp_kind }
      where
        arity :: Arity
    arity   = [GenLocated SrcSpanAnnA (HsType GhcRn)] -> Arity
    forall (t :: * -> *) a. Foldable t => t a -> Arity
    length [GenLocated SrcSpanAnnA (HsType GhcRn)]
    [LHsType GhcRn]
    tys

    finish_tuple :: HsType GhcRn
                 -> TupleSort
                 -> [TcType]    -- ^ argument types
                 -> [TcKind]    -- ^ of these kinds
                 -> TcKind      -- ^ expected kind of the whole tuple
                 -> TcM TcType
    finish_tuple :: HsType GhcRn -> TupleSort -> [Type] -> [Type] -> Type -> TcM Type
    finish_tuple HsType GhcRn
    rn_ty TupleSort
    tup_sort [Type]
    tau_tys [Type]
    tau_kinds Type
    exp_kind = do
      String -> SDoc -> TcM ()
    traceTc String
    "finish_tuple" (TupleSort -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr TupleSort
    tup_sort SDoc -> SDoc -> SDoc
    $$ [Type] -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr [Type]
    tau_kinds SDoc -> SDoc -> SDoc
    $$ Type -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr Type
    exp_kind)
      case TupleSort
    tup_sort of
        TupleSort
    ConstraintTuple
          |  [Type
    tau_ty] <- [Type]
    tau_tys
             -- Drop any uses of 1-tuple constraints here.
             -- See Note [Ignore unary constraint tuples]
          -> Type -> Type -> TcM Type
    check_expected_kind Type
    tau_ty Type
    constraintKind
          |  Bool
    otherwise
          -> do let tycon :: TyCon
    tycon = Arity -> TyCon
    cTupleTyCon Arity
    arity
                Arity -> TcM ()
    checkCTupSize Arity
    arity
                Type -> Type -> TcM Type
    check_expected_kind (TyCon -> [Type] -> Type
    mkTyConApp TyCon
    tycon [Type]
    tau_tys) Type
    constraintKind
        TupleSort
    BoxedTuple -> do
          let tycon :: TyCon
    tycon = Boxity -> Arity -> TyCon
    tupleTyCon Boxity
    Boxed Arity
    arity
          Arity -> TcM ()
    checkTupSize Arity
    arity
          TyCon -> TcM ()
    checkWiredInTyCon TyCon
    tycon
          Type -> Type -> TcM Type
    check_expected_kind (TyCon -> [Type] -> Type
    mkTyConApp TyCon
    tycon [Type]
    tau_tys) Type
    liftedTypeKind
        TupleSort
    UnboxedTuple -> do
          let tycon :: TyCon
    tycon    = Boxity -> Arity -> TyCon
    tupleTyCon Boxity
    Unboxed Arity
    arity
              tau_reps :: [Type]
    tau_reps = (Type -> Type) -> [Type] -> [Type]
    forall a b. (a -> b) -> [a] -> [b]
    map HasDebugCallStack => Type -> Type
    Type -> Type
    kindRep [Type]
    tau_kinds
              -- See also Note [Unboxed tuple RuntimeRep vars] in GHC.Core.TyCon
              arg_tys :: [Type]
    arg_tys  = [Type]
    tau_reps [Type] -> [Type] -> [Type]
    forall a. [a] -> [a] -> [a]
    ++ [Type]
    tau_tys
              res_kind :: Type
    res_kind = [Type] -> Type
    unboxedTupleKind [Type]
    tau_reps
          Arity -> TcM ()
    checkTupSize Arity
    arity
          Type -> Type -> TcM Type
    check_expected_kind (TyCon -> [Type] -> Type
    mkTyConApp TyCon
    tycon [Type]
    arg_tys) Type
    res_kind
      where
        arity :: Arity
    arity = [Type] -> Arity
    forall (t :: * -> *) a. Foldable t => t a -> Arity
    length [Type]
    tau_tys
        check_expected_kind :: Type -> Type -> TcM Type
    check_expected_kind Type
    ty Type
    act_kind =
          HasDebugCallStack =>
    HsType GhcRn -> Type -> Type -> Type -> TcM Type
    HsType GhcRn -> Type -> Type -> Type -> TcM Type
    checkExpectedKind HsType GhcRn
    rn_ty Type
    ty Type
    act_kind Type
    exp_kind

    {-
    Note [Ignore unary constraint tuples]
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    GHC provides unary tuples and unboxed tuples (see Note [One-tuples] in
    GHC.Builtin.Types) but does *not* provide unary constraint tuples. Why? First,
    recall the definition of a unary tuple data type:

      data Solo a = Solo a

    Note that `Solo a` is *not* the same thing as `a`, since Solo is boxed and
    lazy. Therefore, the presence of `Solo` matters semantically. On the other
    hand, suppose we had a unary constraint tuple:

      class a => Solo% a

    This compiles down a newtype (i.e., a cast) in Core, so `Solo% a` is
    semantically equivalent to `a`. Therefore, a 1-tuple constraint would have
    no user-visible impact, nor would it allow you to express anything that
    you couldn't otherwise.

    We could simply add Solo% for consistency with tuples (Solo) and unboxed
    tuples (Solo#), but that would require even more magic to wire in another
    magical class, so we opt not to do so. We must be careful, however, since
    one can try to sneak in uses of unary constraint tuples through Template
    Haskell, such as in this program (from #17511):

      f :: $(pure (ForallT [] [TupleT 1 `AppT` (ConT ''Show `AppT` ConT ''Int)]
                           (ConT ''String)))
      -- f :: Solo% (Show Int) => String
      f = "abc"

    This use of `TupleT 1` will produce an HsBoxedOrConstraintTuple of arity 1,
    and since it is used in a Constraint position, GHC will attempt to treat
    it as thought it were a constraint tuple, which can potentially lead to
    trouble if one attempts to look up the name of a constraint tuple of arity
    1 (as it won't exist). To avoid this trouble, we simply take any unary
    constraint tuples discovered when typechecking and drop them—i.e., treat
    "Solo% a" as though the user had written "a". This is always safe to do
    since the two constraints should be semantically equivalent.
    -}

    {- *********************************************************************
    *                                                                      *
                    Type applications
    *                                                                      *
    ********************************************************************* -}

    splitHsAppTys :: HsType GhcRn -> Maybe (LHsType GhcRn, [LHsTypeArg GhcRn])
    splitHsAppTys :: HsType GhcRn -> Maybe (LHsType GhcRn, HsTyPats GhcRn)
    splitHsAppTys HsType GhcRn
    hs_ty
      | HsType GhcRn -> Bool
    is_app HsType GhcRn
    hs_ty = (GenLocated SrcSpanAnnA (HsType GhcRn),
     [HsArg
        (GenLocated SrcSpanAnnA (HsType GhcRn))
        (GenLocated SrcSpanAnnA (HsType GhcRn))])
    -> Maybe
         (GenLocated SrcSpanAnnA (HsType GhcRn),
          [HsArg
             (GenLocated SrcSpanAnnA (HsType GhcRn))
             (GenLocated SrcSpanAnnA (HsType GhcRn))])
    forall a. a -> Maybe a
    Just (LHsType GhcRn -> HsTyPats GhcRn -> (LHsType GhcRn, HsTyPats GhcRn)
    go (HsType GhcRn -> GenLocated SrcSpanAnnA (HsType GhcRn)
    forall a an. a -> LocatedAn an a
    noLocA HsType GhcRn
    hs_ty) [])
      | Bool
    otherwise    = Maybe (LHsType GhcRn, HsTyPats GhcRn)
    forall a. Maybe a
    Nothing
      where
        is_app :: HsType GhcRn -> Bool
        is_app :: HsType GhcRn -> Bool
    is_app (HsAppKindTy {})        = Bool
    True
        is_app (HsAppTy {})            = Bool
    True
        is_app (HsOpTy XOpTy GhcRn
    _ LHsType GhcRn
    _ (L SrcSpanAnnN
    _ Name
    op) LHsType GhcRn
    _) = Bool -> Bool
    not (Name
    op Name -> Unique -> Bool
    forall a. Uniquable a => a -> Unique -> Bool
    `hasKey` Unique
    funTyConKey)
          -- I'm not sure why this funTyConKey test is necessary
          -- Can it even happen?  Perhaps for   t1 `(->)` t2
          -- but then maybe it's ok to treat that like a normal
          -- application rather than using the special rule for HsFunTy
        is_app (HsTyVar {})            = Bool
    True
        is_app (HsParTy XParTy GhcRn
    _ (L SrcSpanAnnA
    _ HsType GhcRn
    ty))    = HsType GhcRn -> Bool
    is_app HsType GhcRn
    ty
        is_app HsType GhcRn
    _                       = Bool
    False

        go :: LHsType GhcRn
           -> [HsArg (LHsType GhcRn) (LHsKind GhcRn)]
           -> (LHsType GhcRn,
               [HsArg (LHsType GhcRn) (LHsKind GhcRn)]) -- AZ temp
        go :: LHsType GhcRn -> HsTyPats GhcRn -> (LHsType GhcRn, HsTyPats GhcRn)
    go (L SrcSpanAnnA
    _  (HsAppTy XAppTy GhcRn
    _ LHsType GhcRn
    f LHsType GhcRn
    a))      HsTyPats GhcRn
    as = LHsType GhcRn -> HsTyPats GhcRn -> (LHsType GhcRn, HsTyPats GhcRn)
    go LHsType GhcRn
    f (GenLocated SrcSpanAnnA (HsType GhcRn)
    -> HsArg
         (GenLocated SrcSpanAnnA (HsType GhcRn))
         (GenLocated SrcSpanAnnA (HsType GhcRn))
    forall tm ty. tm -> HsArg tm ty
    HsValArg GenLocated SrcSpanAnnA (HsType GhcRn)
    LHsType GhcRn
    a HsArg
      (GenLocated SrcSpanAnnA (HsType GhcRn))
      (GenLocated SrcSpanAnnA (HsType GhcRn))
    -> [HsArg
          (GenLocated SrcSpanAnnA (HsType GhcRn))
          (GenLocated SrcSpanAnnA (HsType GhcRn))]
    -> [HsArg
          (GenLocated SrcSpanAnnA (HsType GhcRn))
          (GenLocated SrcSpanAnnA (HsType GhcRn))]
    forall a. a -> [a] -> [a]
    : [HsArg
       (GenLocated SrcSpanAnnA (HsType GhcRn))
       (GenLocated SrcSpanAnnA (HsType GhcRn))]
    HsTyPats GhcRn
    as)
        go (L SrcSpanAnnA
    _  (HsAppKindTy XAppKindTy GhcRn
    l LHsType GhcRn
    ty LHsType GhcRn
    k)) HsTyPats GhcRn
    as = LHsType GhcRn -> HsTyPats GhcRn -> (LHsType GhcRn, HsTyPats GhcRn)
    go LHsType GhcRn
    ty (SrcSpan
    -> GenLocated SrcSpanAnnA (HsType GhcRn)
    -> HsArg
         (GenLocated SrcSpanAnnA (HsType GhcRn))
         (GenLocated SrcSpanAnnA (HsType GhcRn))
    forall tm ty. SrcSpan -> ty -> HsArg tm ty
    HsTypeArg SrcSpan
    XAppKindTy GhcRn
    l GenLocated SrcSpanAnnA (HsType GhcRn)
    LHsType GhcRn
    k HsArg
      (GenLocated SrcSpanAnnA (HsType GhcRn))
      (GenLocated SrcSpanAnnA (HsType GhcRn))
    -> [HsArg
          (GenLocated SrcSpanAnnA (HsType GhcRn))
          (GenLocated SrcSpanAnnA (HsType GhcRn))]
    -> [HsArg
          (GenLocated SrcSpanAnnA (HsType GhcRn))
          (GenLocated SrcSpanAnnA (HsType GhcRn))]
    forall a. a -> [a] -> [a]
    : [HsArg
       (GenLocated SrcSpanAnnA (HsType GhcRn))
       (GenLocated SrcSpanAnnA (HsType GhcRn))]
    HsTyPats GhcRn
    as)
        go (L SrcSpanAnnA
    sp (HsParTy XParTy GhcRn
    _ LHsType GhcRn
    f))        HsTyPats GhcRn
    as = LHsType GhcRn -> HsTyPats GhcRn -> (LHsType GhcRn, HsTyPats GhcRn)
    go LHsType GhcRn
    f (SrcSpan
    -> HsArg
         (GenLocated SrcSpanAnnA (HsType GhcRn))
         (GenLocated SrcSpanAnnA (HsType GhcRn))
    forall tm ty. SrcSpan -> HsArg tm ty
    HsArgPar (SrcSpanAnnA -> SrcSpan
    forall a. SrcSpanAnn' a -> SrcSpan
    locA SrcSpanAnnA
    sp) HsArg
      (GenLocated SrcSpanAnnA (HsType GhcRn))
      (GenLocated SrcSpanAnnA (HsType GhcRn))
    -> [HsArg
          (GenLocated SrcSpanAnnA (HsType GhcRn))
          (GenLocated SrcSpanAnnA (HsType GhcRn))]
    -> [HsArg
          (GenLocated SrcSpanAnnA (HsType GhcRn))
          (GenLocated SrcSpanAnnA (HsType GhcRn))]
    forall a. a -> [a] -> [a]
    : [HsArg
       (GenLocated SrcSpanAnnA (HsType GhcRn))
       (GenLocated SrcSpanAnnA (HsType GhcRn))]
    HsTyPats GhcRn
    as)
        go (L SrcSpanAnnA
    _  (HsOpTy XOpTy GhcRn
    _ LHsType GhcRn
    l op :: LIdP GhcRn
    op@(L SrcSpanAnnN
    sp Name
    _) LHsType GhcRn
    r)) HsTyPats GhcRn
    as
          = ( SrcSpanAnnA
    -> HsType GhcRn -> GenLocated SrcSpanAnnA (HsType GhcRn)
    forall l e. l -> e -> GenLocated l e
    L (SrcSpanAnnN -> SrcSpanAnnA
    forall a ann. SrcSpanAnn' a -> SrcAnn ann
    na2la SrcSpanAnnN
    sp) (XTyVar GhcRn -> PromotionFlag -> LIdP GhcRn -> HsType GhcRn
    forall pass.
    XTyVar pass -> PromotionFlag -> LIdP pass -> HsType pass
    HsTyVar XTyVar GhcRn
    forall a. EpAnn a
    noAnn PromotionFlag
    NotPromoted LIdP GhcRn
    op)
            , GenLocated SrcSpanAnnA (HsType GhcRn)
    -> HsArg
         (GenLocated SrcSpanAnnA (HsType GhcRn))
         (GenLocated SrcSpanAnnA (HsType GhcRn))
    forall tm ty. tm -> HsArg tm ty
    HsValArg GenLocated SrcSpanAnnA (HsType GhcRn)
    LHsType GhcRn
    l HsArg
      (GenLocated SrcSpanAnnA (HsType GhcRn))
      (GenLocated SrcSpanAnnA (HsType GhcRn))
    -> [HsArg
          (GenLocated SrcSpanAnnA (HsType GhcRn))
          (GenLocated SrcSpanAnnA (HsType GhcRn))]
    -> [HsArg
          (GenLocated SrcSpanAnnA (HsType GhcRn))
          (GenLocated SrcSpanAnnA (HsType GhcRn))]
    forall a. a -> [a] -> [a]
    : GenLocated SrcSpanAnnA (HsType GhcRn)
    -> HsArg
         (GenLocated SrcSpanAnnA (HsType GhcRn))
         (GenLocated SrcSpanAnnA (HsType GhcRn))
    forall tm ty. tm -> HsArg tm ty
    HsValArg GenLocated SrcSpanAnnA (HsType GhcRn)
    LHsType GhcRn
    r HsArg
      (GenLocated SrcSpanAnnA (HsType GhcRn))
      (GenLocated SrcSpanAnnA (HsType GhcRn))
    -> [HsArg
          (GenLocated SrcSpanAnnA (HsType GhcRn))
          (GenLocated SrcSpanAnnA (HsType GhcRn))]
    -> [HsArg
          (GenLocated SrcSpanAnnA (HsType GhcRn))
          (GenLocated SrcSpanAnnA (HsType GhcRn))]
    forall a. a -> [a] -> [a]
    : [HsArg
       (GenLocated SrcSpanAnnA (HsType GhcRn))
       (GenLocated SrcSpanAnnA (HsType GhcRn))]
    HsTyPats GhcRn
    as )
        go LHsType GhcRn
    f HsTyPats GhcRn
    as = (LHsType GhcRn
    f, HsTyPats GhcRn
    as)

    ---------------------------
    tcInferTyAppHead :: TcTyMode -> LHsType GhcRn -> TcM (TcType, TcKind)
    -- Version of tc_infer_lhs_type specialised for the head of an
    -- application. In particular, for a HsTyVar (which includes type
    -- constructors, it does not zoom off into tcInferTyApps and family
    -- saturation
    tcInferTyAppHead :: TcTyMode -> LHsType GhcRn -> TcM (Type, Type)
    tcInferTyAppHead TcTyMode
    mode (L SrcSpanAnnA
    _ (HsTyVar XTyVar GhcRn
    _ PromotionFlag
    _ (L SrcSpanAnnN
    _ Name
    tv)))
      = TcTyMode -> Name -> TcM (Type, Type)
    tcTyVar TcTyMode
    mode Name
    tv
    tcInferTyAppHead TcTyMode
    mode LHsType GhcRn
    ty
      = TcTyMode -> LHsType GhcRn -> TcM (Type, Type)
    tc_infer_lhs_type TcTyMode
    mode LHsType GhcRn
    ty

    ---------------------------
    -- | Apply a type of a given kind to a list of arguments. This instantiates
    -- invisible parameters as necessary. Always consumes all the arguments,
    -- using matchExpectedFunKind as necessary.
    -- This takes an optional @VarEnv Kind@ which maps kind variables to kinds.-
    -- These kinds should be used to instantiate invisible kind variables;
    -- they come from an enclosing class for an associated type/data family.
    --
    -- tcInferTyApps also arranges to saturate any trailing invisible arguments
    --   of a type-family application, which is usually the right thing to do
    -- tcInferTyApps_nosat does not do this saturation; it is used only
    --   by ":kind" in GHCi
    tcInferTyApps, tcInferTyApps_nosat
        :: TcTyMode
        -> LHsType GhcRn        -- ^ Function (for printing only)
        -> TcType               -- ^ Function
        -> [LHsTypeArg GhcRn]   -- ^ Args
        -> TcM (TcType, TcKind) -- ^ (f args, args, result kind)
    tcInferTyApps :: TcTyMode
    -> LHsType GhcRn -> Type -> HsTyPats GhcRn -> TcM (Type, Type)
    tcInferTyApps TcTyMode
    mode LHsType GhcRn
    hs_ty Type
    fun HsTyPats GhcRn
    hs_args
      = do { (Type
    f_args, Type
    res_k) <- TcTyMode
    -> LHsType GhcRn -> Type -> HsTyPats GhcRn -> TcM (Type, Type)
    tcInferTyApps_nosat TcTyMode
    mode LHsType GhcRn
    hs_ty Type
    fun HsTyPats GhcRn
    hs_args
           ; Type -> Type -> TcM (Type, Type)
    saturateFamApp Type
    f_args Type
    res_k }

    tcInferTyApps_nosat :: TcTyMode
    -> LHsType GhcRn -> Type -> HsTyPats GhcRn -> TcM (Type, Type)
    tcInferTyApps_nosat TcTyMode
    mode LHsType GhcRn
    orig_hs_ty Type
    fun HsTyPats GhcRn
    orig_hs_args
      = do { String -> SDoc -> TcM ()
    traceTc String
    "tcInferTyApps {" (GenLocated SrcSpanAnnA (HsType GhcRn) -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr GenLocated SrcSpanAnnA (HsType GhcRn)
    LHsType GhcRn
    orig_hs_ty SDoc -> SDoc -> SDoc
    $$ [HsArg
       (GenLocated SrcSpanAnnA (HsType GhcRn))
       (GenLocated SrcSpanAnnA (HsType GhcRn))]
    -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr [HsArg
       (GenLocated SrcSpanAnnA (HsType GhcRn))
       (GenLocated SrcSpanAnnA (HsType GhcRn))]
    HsTyPats GhcRn
    orig_hs_args)
           ; (Type
    f_args, Type
    res_k) <- Arity
    -> Type
    -> [HsArg
          (GenLocated SrcSpanAnnA (HsType GhcRn))
          (GenLocated SrcSpanAnnA (HsType GhcRn))]
    -> TcM (Type, Type)
    go_init Arity
    1 Type
    fun [HsArg
       (GenLocated SrcSpanAnnA (HsType GhcRn))
       (GenLocated SrcSpanAnnA (HsType GhcRn))]
    HsTyPats GhcRn
    orig_hs_args
           ; String -> SDoc -> TcM ()
    traceTc String
    "tcInferTyApps }" (Type -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr Type
    f_args SDoc -> SDoc -> SDoc
    <+> SDoc
    dcolon SDoc -> SDoc -> SDoc
    <+> Type -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr Type
    res_k)
           ; (Type, Type) -> TcM (Type, Type)
    forall (m :: * -> *) a. Monad m => a -> m a
    return (Type
    f_args, Type
    res_k) }
      where

        -- go_init just initialises the auxiliary
        -- arguments of the 'go' loop
        go_init :: Arity
    -> Type
    -> [HsArg
          (GenLocated SrcSpanAnnA (HsType GhcRn))
          (GenLocated SrcSpanAnnA (HsType GhcRn))]
    -> TcM (Type, Type)
    go_init Arity
    n Type
    fun [HsArg
       (GenLocated SrcSpanAnnA (HsType GhcRn))
       (GenLocated SrcSpanAnnA (HsType GhcRn))]
    all_args
          = Arity
    -> Type -> TCvSubst -> Type -> HsTyPats GhcRn -> TcM (Type, Type)
    go Arity
    n Type
    fun TCvSubst
    empty_subst Type
    fun_ki [HsArg
       (GenLocated SrcSpanAnnA (HsType GhcRn))
       (GenLocated SrcSpanAnnA (HsType GhcRn))]
    HsTyPats GhcRn
    all_args
          where
            fun_ki :: Type
    fun_ki = HasDebugCallStack => Type -> Type
    Type -> Type
    tcTypeKind Type
    fun
               -- We do (tcTypeKind fun) here, even though the caller
               -- knows the function kind, to absolutely guarantee
               -- INVARIANT for 'go'
               -- Note that in a typical application (F t1 t2 t3),
               -- the 'fun' is just a TyCon, so tcTypeKind is fast

            empty_subst :: TCvSubst
    empty_subst = InScopeSet -> TCvSubst
    mkEmptyTCvSubst (InScopeSet -> TCvSubst) -> InScopeSet -> TCvSubst
    forall a b. (a -> b) -> a -> b
    $ VarSet -> InScopeSet
    mkInScopeSet (VarSet -> InScopeSet) -> VarSet -> InScopeSet
    forall a b. (a -> b) -> a -> b
    $
                          Type -> VarSet
    tyCoVarsOfType Type
    fun_ki

        go :: Int             -- The # of the next argument
           -> TcType          -- Function applied to some args
           -> TCvSubst        -- Applies to function kind
           -> TcKind          -- Function kind
           -> [LHsTypeArg GhcRn]    -- Un-type-checked args
           -> TcM (TcType, TcKind)  -- Result type and its kind
        -- INVARIANT: in any call (go n fun subst fun_ki args)
        --               tcTypeKind fun  =  subst(fun_ki)
        -- So the 'subst' and 'fun_ki' arguments are simply
        -- there to avoid repeatedly calling tcTypeKind.
        --
        -- Reason for INVARIANT: to support the Purely Kinded Type Invariant
        -- it's important that if fun_ki has a forall, then so does
        -- (tcTypeKind fun), because the next thing we are going to do
        -- is apply 'fun' to an argument type.

        -- Dispatch on all_args first, for performance reasons
        go :: Arity
    -> Type -> TCvSubst -> Type -> HsTyPats GhcRn -> TcM (Type, Type)
    go Arity
    n Type
    fun TCvSubst
    subst Type
    fun_ki HsTyPats GhcRn
    all_args = case ([HsArg
       (GenLocated SrcSpanAnnA (HsType GhcRn))
       (GenLocated SrcSpanAnnA (HsType GhcRn))]
    HsTyPats GhcRn
    all_args, Type -> Maybe (TyBinder, Type)
    tcSplitPiTy_maybe Type
    fun_ki) of

          ---------------- No user-written args left. We're done!
          ([], Maybe (TyBinder, Type)
    _) -> (Type, Type) -> TcM (Type, Type)
    forall (m :: * -> *) a. Monad m => a -> m a
    return (Type
    fun, HasCallStack => TCvSubst -> Type -> Type
    TCvSubst -> Type -> Type
    substTy TCvSubst
    subst Type
    fun_ki)

          ---------------- HsArgPar: We don't care about parens here
          (HsArgPar SrcSpan
    _ : [HsArg
       (GenLocated SrcSpanAnnA (HsType GhcRn))
       (GenLocated SrcSpanAnnA (HsType GhcRn))]
    args, Maybe (TyBinder, Type)
    _) -> Arity
    -> Type -> TCvSubst -> Type -> HsTyPats GhcRn -> TcM (Type, Type)
    go Arity
    n Type
    fun TCvSubst
    subst Type
    fun_ki [HsArg
       (GenLocated SrcSpanAnnA (HsType GhcRn))
       (GenLocated SrcSpanAnnA (HsType GhcRn))]
    HsTyPats GhcRn
    args

          ---------------- HsTypeArg: a kind application (fun @ki)
          (HsTypeArg SrcSpan
    _ GenLocated SrcSpanAnnA (HsType GhcRn)
    hs_ki_arg : [HsArg
       (GenLocated SrcSpanAnnA (HsType GhcRn))
       (GenLocated SrcSpanAnnA (HsType GhcRn))]
    hs_args, Just (TyBinder
    ki_binder, Type
    inner_ki)) ->
            case TyBinder
    ki_binder of

            -- FunTy with PredTy on LHS, or ForAllTy with Inferred
            Named (Bndr TyVar
    _ ArgFlag
    Inferred) -> TyBinder -> Type -> TcM (Type, Type)
    instantiate TyBinder
    ki_binder Type
    inner_ki
            Anon AnonArgFlag
    InvisArg Scaled Type
    _         -> TyBinder -> Type -> TcM (Type, Type)
    instantiate TyBinder
    ki_binder Type
    inner_ki

            Named (Bndr TyVar
    _ ArgFlag
    Specified) ->  -- Visible kind application
              do { String -> SDoc -> TcM ()
    traceTc String
    "tcInferTyApps (vis kind app)"
                           ([SDoc] -> SDoc
    vcat [ TyBinder -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr TyBinder
    ki_binder, GenLocated SrcSpanAnnA (HsType GhcRn) -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr GenLocated SrcSpanAnnA (HsType GhcRn)
    hs_ki_arg
                                 , Type -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr (TyBinder -> Type
    tyBinderType TyBinder
    ki_binder)
                                 , TCvSubst -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr TCvSubst
    subst ])

                 ; let exp_kind :: Type
    exp_kind = HasCallStack => TCvSubst -> Type -> Type
    TCvSubst -> Type -> Type
    substTy TCvSubst
    subst (Type -> Type) -> Type -> Type
    forall a b. (a -> b) -> a -> b
    $ TyBinder -> Type
    tyBinderType TyBinder
    ki_binder
                 ; TcTyMode
    arg_mode <- TypeOrKind -> HoleMode -> TcM TcTyMode
    mkHoleMode TypeOrKind
    KindLevel HoleMode
    HM_VTA
                       -- HM_VKA: see Note [Wildcards in visible kind application]
                 ; Type
    ki_arg <- SDoc -> TcM Type -> TcM Type
    forall a. SDoc -> TcM a -> TcM a
    addErrCtxt (GenLocated SrcSpanAnnA (HsType GhcRn)
    -> GenLocated SrcSpanAnnA (HsType GhcRn) -> Arity -> SDoc
    forall fun arg.
    (Outputable fun, Outputable arg) =>
    fun -> arg -> Arity -> SDoc
    funAppCtxt GenLocated SrcSpanAnnA (HsType GhcRn)
    LHsType GhcRn
    orig_hs_ty GenLocated SrcSpanAnnA (HsType GhcRn)
    hs_ki_arg Arity
    n) (TcM Type -> TcM Type) -> TcM Type -> TcM Type
    forall a b. (a -> b) -> a -> b
    $
                             TcTyMode -> LHsType GhcRn -> Type -> TcM Type
    tc_lhs_type TcTyMode
    arg_mode GenLocated SrcSpanAnnA (HsType GhcRn)
    LHsType GhcRn
    hs_ki_arg Type
    exp_kind

                 ; String -> SDoc -> TcM ()
    traceTc String
    "tcInferTyApps (vis kind app)" (Type -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr Type
    exp_kind)
                 ; (TCvSubst
    subst', Type
    fun') <- TCvSubst -> Type -> TyBinder -> Type -> TcM (TCvSubst, Type)
    mkAppTyM TCvSubst
    subst Type
    fun TyBinder
    ki_binder Type
    ki_arg
                 ; Arity
    -> Type -> TCvSubst -> Type -> HsTyPats GhcRn -> TcM (Type, Type)
    go (Arity
    nArity -> Arity -> Arity
    forall a. Num a => a -> a -> a
    +Arity
    1) Type
    fun' TCvSubst
    subst' Type
    inner_ki [HsArg
       (GenLocated SrcSpanAnnA (HsType GhcRn))
       (GenLocated SrcSpanAnnA (HsType GhcRn))]
    HsTyPats GhcRn
    hs_args }

            -- Attempted visible kind application (fun @ki), but fun_ki is
            --   forall k -> blah   or   k1 -> k2
            -- So we need a normal application.  Error.
            TyBinder
    _ -> GenLocated SrcSpanAnnA (HsType GhcRn) -> Type -> TcM (Type, Type)
    forall {a} {a} {a}.
    (Outputable a, Outputable a) =>
    a -> a -> TcRn a
    ty_app_err GenLocated SrcSpanAnnA (HsType GhcRn)
    hs_ki_arg (Type -> TcM (Type, Type)) -> Type -> TcM (Type, Type)
    forall a b. (a -> b) -> a -> b
    $ HasCallStack => TCvSubst -> Type -> Type
    TCvSubst -> Type -> Type
    substTy TCvSubst
    subst Type
    fun_ki

          -- No binder; try applying the substitution, or fail if that's not possible
          (HsTypeArg SrcSpan
    _ GenLocated SrcSpanAnnA (HsType GhcRn)
    ki_arg : [HsArg
       (GenLocated SrcSpanAnnA (HsType GhcRn))
       (GenLocated SrcSpanAnnA (HsType GhcRn))]
    _, Maybe (TyBinder, Type)
    Nothing) -> TcM (Type, Type) -> TcM (Type, Type)
    try_again_after_substing_or (TcM (Type, Type) -> TcM (Type, Type))
    -> TcM (Type, Type) -> TcM (Type, Type)
    forall a b. (a -> b) -> a -> b
    $
                                               GenLocated SrcSpanAnnA (HsType GhcRn) -> Type -> TcM (Type, Type)
    forall {a} {a} {a}.
    (Outputable a, Outputable a) =>
    a -> a -> TcRn a
    ty_app_err GenLocated SrcSpanAnnA (HsType GhcRn)
    ki_arg Type
    substed_fun_ki

          ---------------- HsValArg: a normal argument (fun ty)
          (HsValArg GenLocated SrcSpanAnnA (HsType GhcRn)
    arg : [HsArg
       (GenLocated SrcSpanAnnA (HsType GhcRn))
       (GenLocated SrcSpanAnnA (HsType GhcRn))]
    args, Just (TyBinder
    ki_binder, Type
    inner_ki))
            -- next binder is invisible; need to instantiate it
            | TyBinder -> Bool
    isInvisibleBinder TyBinder
    ki_binder   -- FunTy with InvisArg on LHS;
                                            -- or ForAllTy with Inferred or Specified
             -> TyBinder -> Type -> TcM (Type, Type)
    instantiate TyBinder
    ki_binder Type
    inner_ki

            -- "normal" case
            | Bool
    otherwise
             -> do { String -> SDoc -> TcM ()
    traceTc String
    "tcInferTyApps (vis normal app)"
                              ([SDoc] -> SDoc
    vcat [ TyBinder -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr TyBinder
    ki_binder
                                    , GenLocated SrcSpanAnnA (HsType GhcRn) -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr GenLocated SrcSpanAnnA (HsType GhcRn)
    arg
                                    , Type -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr (TyBinder -> Type
    tyBinderType TyBinder
    ki_binder)
                                    , TCvSubst -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr TCvSubst
    subst ])
                    ; let exp_kind :: Type
    exp_kind = HasCallStack => TCvSubst -> Type -> Type
    TCvSubst -> Type -> Type
    substTy TCvSubst
    subst (Type -> Type) -> Type -> Type
    forall a b. (a -> b) -> a -> b
    $ TyBinder -> Type
    tyBinderType TyBinder
    ki_binder
                    ; Type
    arg' <- SDoc -> TcM Type -> TcM Type
    forall a. SDoc -> TcM a -> TcM a
    addErrCtxt (GenLocated SrcSpanAnnA (HsType GhcRn)
    -> GenLocated SrcSpanAnnA (HsType GhcRn) -> Arity -> SDoc
    forall fun arg.
    (Outputable fun, Outputable arg) =>
    fun -> arg -> Arity -> SDoc
    funAppCtxt GenLocated SrcSpanAnnA (HsType GhcRn)
    LHsType GhcRn
    orig_hs_ty GenLocated SrcSpanAnnA (HsType GhcRn)
    arg Arity
    n) (TcM Type -> TcM Type) -> TcM Type -> TcM Type
    forall a b. (a -> b) -> a -> b
    $
                              TcTyMode -> LHsType GhcRn -> Type -> TcM Type
    tc_lhs_type TcTyMode
    mode GenLocated SrcSpanAnnA (HsType GhcRn)
    LHsType GhcRn
    arg Type
    exp_kind
                    ; String -> SDoc -> TcM ()
    traceTc String
    "tcInferTyApps (vis normal app) 2" (Type -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr Type
    exp_kind)
                    ; (TCvSubst
    subst', Type
    fun') <- TCvSubst -> Type -> TyBinder -> Type -> TcM (TCvSubst, Type)
    mkAppTyM TCvSubst
    subst Type
    fun TyBinder
    ki_binder Type
    arg'
                    ; Arity
    -> Type -> TCvSubst -> Type -> HsTyPats GhcRn -> TcM (Type, Type)
    go (Arity
    nArity -> Arity -> Arity
    forall a. Num a => a -> a -> a
    +Arity
    1) Type
    fun' TCvSubst
    subst' Type
    inner_ki [HsArg
       (GenLocated SrcSpanAnnA (HsType GhcRn))
       (GenLocated SrcSpanAnnA (HsType GhcRn))]
    HsTyPats GhcRn
    args }

              -- no binder; try applying the substitution, or infer another arrow in fun kind
          (HsValArg GenLocated SrcSpanAnnA (HsType GhcRn)
    _ : [HsArg
       (GenLocated SrcSpanAnnA (HsType GhcRn))
       (GenLocated SrcSpanAnnA (HsType GhcRn))]
    _, Maybe (TyBinder, Type)
    Nothing)
            -> TcM (Type, Type) -> TcM (Type, Type)
    try_again_after_substing_or (TcM (Type, Type) -> TcM (Type, Type))
    -> TcM (Type, Type) -> TcM (Type, Type)
    forall a b. (a -> b) -> a -> b
    $
               do { let arrows_needed :: Arity
    arrows_needed = [HsArg
       (GenLocated SrcSpanAnnA (HsType GhcRn))
       (GenLocated SrcSpanAnnA (HsType GhcRn))]
    -> Arity
    forall tm ty. [HsArg tm ty] -> Arity
    n_initial_val_args [HsArg
       (GenLocated SrcSpanAnnA (HsType GhcRn))
       (GenLocated SrcSpanAnnA (HsType GhcRn))]
    HsTyPats GhcRn
    all_args
                  ; Coercion
    co <- GenLocated SrcSpanAnnA (HsType GhcRn)
    -> Arity -> Type -> TcM Coercion
    forall fun. Outputable fun => fun -> Arity -> Type -> TcM Coercion
    matchExpectedFunKind GenLocated SrcSpanAnnA (HsType GhcRn)
    LHsType GhcRn
    hs_ty Arity
    arrows_needed Type
    substed_fun_ki

                  ; Type
    fun' <- Type -> TcM Type
    zonkTcType (Type
    fun Type -> Coercion -> Type
    `mkTcCastTy` Coercion
    co)
                         -- This zonk is essential, to expose the fruits
                         -- of matchExpectedFunKind to the 'go' loop

                  ; String -> SDoc -> TcM ()
    traceTc String
    "tcInferTyApps (no binder)" (SDoc -> TcM ()) -> SDoc -> TcM ()
    forall a b. (a -> b) -> a -> b
    $
                       [SDoc] -> SDoc
    vcat [ Type -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr Type
    fun SDoc -> SDoc -> SDoc
    <+> SDoc
    dcolon SDoc -> SDoc -> SDoc
    <+> Type -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr Type
    fun_ki
                            , Arity -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr Arity
    arrows_needed
                            , Coercion -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr Coercion
    co
                            , Type -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr Type
    fun' SDoc -> SDoc -> SDoc
    <+> SDoc
    dcolon SDoc -> SDoc -> SDoc
    <+> Type -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr (HasDebugCallStack => Type -> Type
    Type -> Type
    tcTypeKind Type
    fun')]
                  ; Arity
    -> Type
    -> [HsArg
          (GenLocated SrcSpanAnnA (HsType GhcRn))
          (GenLocated SrcSpanAnnA (HsType GhcRn))]
    -> TcM (Type, Type)
    go_init Arity
    n Type
    fun' [HsArg
       (GenLocated SrcSpanAnnA (HsType GhcRn))
       (GenLocated SrcSpanAnnA (HsType GhcRn))]
    HsTyPats GhcRn
    all_args }
                    -- Use go_init to establish go's INVARIANT
          where
            instantiate :: TyBinder -> Type -> TcM (Type, Type)
    instantiate TyBinder
    ki_binder Type
    inner_ki
              = do { String -> SDoc -> TcM ()
    traceTc String
    "tcInferTyApps (need to instantiate)"
                             ([SDoc] -> SDoc
    vcat [ TyBinder -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr TyBinder
    ki_binder, TCvSubst -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr TCvSubst
    subst])
                   ; (TCvSubst
    subst', Type
    arg') <- TCvSubst -> TyBinder -> TcM (TCvSubst, Type)
    tcInstInvisibleTyBinder TCvSubst
    subst TyBinder
    ki_binder
                   ; Arity
    -> Type -> TCvSubst -> Type -> HsTyPats GhcRn -> TcM (Type, Type)
    go Arity
    n (Type -> Type -> Type
    mkAppTy Type
    fun Type
    arg') TCvSubst
    subst' Type
    inner_ki HsTyPats GhcRn
    all_args }
                     -- Because tcInvisibleTyBinder instantiate ki_binder,
                     -- the kind of arg' will have the same shape as the kind
                     -- of ki_binder.  So we don't need mkAppTyM here.

            try_again_after_substing_or :: TcM (Type, Type) -> TcM (Type, Type)
    try_again_after_substing_or TcM (Type, Type)
    fallthrough
              | Bool -> Bool
    not (TCvSubst -> Bool
    isEmptyTCvSubst TCvSubst
    subst)
              = Arity
    -> Type -> TCvSubst -> Type -> HsTyPats GhcRn -> TcM (Type, Type)
    go Arity
    n Type
    fun TCvSubst
    zapped_subst Type
    substed_fun_ki HsTyPats GhcRn
    all_args
              | Bool
    otherwise
              = TcM (Type, Type)
    fallthrough

            zapped_subst :: TCvSubst
    zapped_subst   = TCvSubst -> TCvSubst
    zapTCvSubst TCvSubst
    subst
            substed_fun_ki :: Type
    substed_fun_ki = HasCallStack => TCvSubst -> Type -> Type
    TCvSubst -> Type -> Type
    substTy TCvSubst
    subst Type
    fun_ki
            hs_ty :: LHsType GhcRn
    hs_ty          = LHsType GhcRn -> HsTyPats GhcRn -> LHsType GhcRn
    appTypeToArg LHsType GhcRn
    orig_hs_ty (Arity
    -> [HsArg
          (GenLocated SrcSpanAnnA (HsType GhcRn))
          (GenLocated SrcSpanAnnA (HsType GhcRn))]
    -> [HsArg
          (GenLocated SrcSpanAnnA (HsType GhcRn))
          (GenLocated SrcSpanAnnA (HsType GhcRn))]
    forall a. Arity -> [a] -> [a]
    take (Arity
    nArity -> Arity -> Arity
    forall a. Num a => a -> a -> a
    -Arity
    1) [HsArg
       (GenLocated SrcSpanAnnA (HsType GhcRn))
       (GenLocated SrcSpanAnnA (HsType GhcRn))]
    HsTyPats GhcRn
    orig_hs_args)

        n_initial_val_args :: [HsArg tm ty] -> Arity
        -- Count how many leading HsValArgs we have
        n_initial_val_args :: forall tm ty. [HsArg tm ty] -> Arity
    n_initial_val_args (HsValArg {} : [HsArg tm ty]
    args) = Arity
    1 Arity -> Arity -> Arity
    forall a. Num a => a -> a -> a
    + [HsArg tm ty] -> Arity
    forall tm ty. [HsArg tm ty] -> Arity
    n_initial_val_args [HsArg tm ty]
    args
        n_initial_val_args (HsArgPar {} : [HsArg tm ty]
    args) = [HsArg tm ty] -> Arity
    forall tm ty. [HsArg tm ty] -> Arity
    n_initial_val_args [HsArg tm ty]
    args
        n_initial_val_args [HsArg tm ty]
    _                    = Arity
    0

        ty_app_err :: a -> a -> TcRn a
    ty_app_err a
    arg a
    ty
          = SDoc -> TcRn a
    forall a. SDoc -> TcM a
    failWith (SDoc -> TcRn a) -> SDoc -> TcRn a
    forall a b. (a -> b) -> a -> b
    $ String -> SDoc
    text String
    "Cannot apply function of kind" SDoc -> SDoc -> SDoc
    <+> SDoc -> SDoc
    quotes (a -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr a
    ty)
                    SDoc -> SDoc -> SDoc
    $$ String -> SDoc
    text String
    "to visible kind argument" SDoc -> SDoc -> SDoc
    <+> SDoc -> SDoc
    quotes (a -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr a
    arg)

    mkAppTyM :: TCvSubst
             -> TcType -> TyCoBinder    -- fun, plus its top-level binder
             -> TcType                  -- arg
             -> TcM (TCvSubst, TcType)  -- Extended subst, plus (fun arg)
    -- Precondition: the application (fun arg) is well-kinded after zonking
    --               That is, the application makes sense
    --
    -- Precondition: for (mkAppTyM subst fun bndr arg)
    --       tcTypeKind fun  =  Pi bndr. body
    --  That is, fun always has a ForAllTy or FunTy at the top
    --           and 'bndr' is fun's pi-binder
    --
    -- Postcondition: if fun and arg satisfy (PKTI), the purely-kinded type
    --                invariant, then so does the result type (fun arg)
    --
    -- We do not require that
    --    tcTypeKind arg = tyVarKind (binderVar bndr)
    -- This must be true after zonking (precondition 1), but it's not
    -- required for the (PKTI).
    mkAppTyM :: TCvSubst -> Type -> TyBinder -> Type -> TcM (TCvSubst, Type)
    mkAppTyM TCvSubst
    subst Type
    fun TyBinder
    ki_binder Type
    arg
      | -- See Note [mkAppTyM]: Nasty case 2
        TyConApp TyCon
    tc [Type]
    args <- Type
    fun
      , TyCon -> Bool
    isTypeSynonymTyCon TyCon
    tc
      , [Type]
    args [Type] -> Arity -> Bool
    forall a. [a] -> Arity -> Bool
    `lengthIs` (TyCon -> Arity
    tyConArity TyCon
    tc Arity -> Arity -> Arity
    forall a. Num a => a -> a -> a
    - Arity
    1)
      , (TyVar -> Bool) -> [TyVar] -> Bool
    forall (t :: * -> *) a. Foldable t => (a -> Bool) -> t a -> Bool
    any TyVar -> Bool
    isTrickyTvBinder (TyCon -> [TyVar]
    tyConTyVars TyCon
    tc) -- We could cache this in the synonym
      = do { Type
    arg'  <- Type -> TcM Type
    zonkTcType  Type
    arg
           ; [Type]
    args' <- [Type] -> TcM [Type]
    zonkTcTypes [Type]
    args
           ; let subst' :: TCvSubst
    subst' = case TyBinder
    ki_binder of
                            Anon {}           -> TCvSubst
    subst
                            Named (Bndr TyVar
    tv ArgFlag
    _) -> TCvSubst -> TyVar -> Type -> TCvSubst
    extendTvSubstAndInScope TCvSubst
    subst TyVar
    tv Type
    arg'
           ; (TCvSubst, Type) -> TcM (TCvSubst, Type)
    forall (m :: * -> *) a. Monad m => a -> m a
    return (TCvSubst
    subst', TyCon -> [Type] -> Type
    mkTyConApp TyCon
    tc ([Type]
    args' [Type] -> [Type] -> [Type]
    forall a. [a] -> [a] -> [a]
    ++ [Type
    arg'])) }

    mkAppTyM TCvSubst
    subst Type
    fun (Anon {}) Type
    arg
       = (TCvSubst, Type) -> TcM (TCvSubst, Type)
    forall (m :: * -> *) a. Monad m => a -> m a
    return (TCvSubst
    subst, Type -> Type -> Type
    mk_app_ty Type
    fun Type
    arg)

    mkAppTyM TCvSubst
    subst Type
    fun (Named (Bndr TyVar
    tv ArgFlag
    _)) Type
    arg
      = do { Type
    arg' <- if TyVar -> Bool
    isTrickyTvBinder TyVar
    tv
                     then -- See Note [mkAppTyM]: Nasty case 1
                          Type -> TcM Type
    zonkTcType Type
    arg
                     else Type -> TcM Type
    forall (m :: * -> *) a. Monad m => a -> m a
    return     Type
    arg
           ; (TCvSubst, Type) -> TcM (TCvSubst, Type)
    forall (m :: * -> *) a. Monad m => a -> m a
    return ( TCvSubst -> TyVar -> Type -> TCvSubst
    extendTvSubstAndInScope TCvSubst
    subst TyVar
    tv Type
    arg'
                    , Type -> Type -> Type
    mk_app_ty Type
    fun Type
    arg' ) }

    mk_app_ty :: TcType -> TcType -> TcType
    -- This function just adds an ASSERT for mkAppTyM's precondition
    mk_app_ty :: Type -> Type -> Type
    mk_app_ty Type
    fun Type
    arg
      = ASSERT2( isPiTy fun_kind
               ,  ppr fun <+> dcolon <+> ppr fun_kind $$ ppr arg )
        Type -> Type -> Type
    mkAppTy Type
    fun Type
    arg
      where
        fun_kind :: Type
    fun_kind = HasDebugCallStack => Type -> Type
    Type -> Type
    tcTypeKind Type
    fun

    isTrickyTvBinder :: TcTyVar -> Bool
    -- NB: isTrickyTvBinder is just an optimisation
    -- It would be absolutely sound to return True always
    isTrickyTvBinder :: TyVar -> Bool
    isTrickyTvBinder TyVar
    tv = Type -> Bool
    isPiTy (TyVar -> Type
    tyVarKind TyVar
    tv)

    {- Note [The Purely Kinded Type Invariant (PKTI)]
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    During type inference, we maintain this invariant

     (PKTI) It is legal to call 'tcTypeKind' on any Type ty,
            on any sub-term of ty, /without/ zonking ty

            Moreover, any such returned kind
            will itself satisfy (PKTI)

    By "legal to call tcTypeKind" we mean "tcTypeKind will not crash".
    The way in which tcTypeKind can crash is in applications
        (a t1 t2 .. tn)
    if 'a' is a type variable whose kind doesn't have enough arrows
    or foralls.  (The crash is in piResultTys.)

    The loop in tcInferTyApps has to be very careful to maintain the (PKTI).
    For example, suppose
        kappa is a unification variable
        We have already unified kappa := Type
          yielding    co :: Refl (Type -> Type)
        a :: kappa
    then consider the type
        (a Int)
    If we call tcTypeKind on that, we'll crash, because the (un-zonked)
    kind of 'a' is just kappa, not an arrow kind.  So we must zonk first.

    So the type inference engine is very careful when building applications.
    This happens in tcInferTyApps. Suppose we are kind-checking the type (a Int),
    where (a :: kappa).  Then in tcInferApps we'll run out of binders on
    a's kind, so we'll call matchExpectedFunKind, and unify
       kappa := kappa1 -> kappa2,  with evidence co :: kappa ~ (kappa1 ~ kappa2)
    At this point we must zonk the function type to expose the arrrow, so
    that (a Int) will satisfy (PKTI).

    The absence of this caused #14174 and #14520.

    The calls to mkAppTyM is the other place we are very careful.

    Note [mkAppTyM]
    ~~~~~~~~~~~~~~~
    mkAppTyM is trying to guarantee the Purely Kinded Type Invariant
    (PKTI) for its result type (fun arg).  There are two ways it can go wrong:

    * Nasty case 1: forall types (polykinds/T14174a)
        T :: forall (p :: *->*). p Int -> p Bool
      Now kind-check (T x), where x::kappa.
      Well, T and x both satisfy the PKTI, but
         T x :: x Int -> x Bool
      and (x Int) does /not/ satisfy the PKTI.

    * Nasty case 2: type synonyms
        type S f a = f a
      Even though (S ff aa) would satisfy the (PKTI) if S was a data type
      (i.e. nasty case 1 is dealt with), it might still not satisfy (PKTI)
      if S is a type synonym, because the /expansion/ of (S ff aa) is
      (ff aa), and /that/ does not satisfy (PKTI).  E.g. perhaps
      (ff :: kappa), where 'kappa' has already been unified with (*->*).

      We check for nasty case 2 on the final argument of a type synonym.

    Notice that in both cases the trickiness only happens if the
    bound variable has a pi-type.  Hence isTrickyTvBinder.
    -}

    saturateFamApp :: TcType -> TcKind -> TcM (TcType, TcKind)
    -- Precondition for (saturateFamApp ty kind):
    --     tcTypeKind ty = kind
    --
    -- If 'ty' is an unsaturated family application with trailing
    -- invisible arguments, instantiate them.
    -- See Note [saturateFamApp]

    saturateFamApp :: Type -> Type -> TcM (Type, Type)
    saturateFamApp Type
    ty Type
    kind
      | Just (TyCon
    tc, [Type]
    args) <- HasCallStack => Type -> Maybe (TyCon, [Type])
    Type -> Maybe (TyCon, [Type])
    tcSplitTyConApp_maybe Type
    ty
      , TyCon -> Bool
    mustBeSaturated TyCon
    tc
      , let n_to_inst :: Arity
    n_to_inst = TyCon -> Arity
    tyConArity TyCon
    tc Arity -> Arity -> Arity
    forall a. Num a => a -> a -> a
    - [Type] -> Arity
    forall (t :: * -> *) a. Foldable t => t a -> Arity
    length [Type]
    args
      = do { ([Type]
    extra_args, Type
    ki') <- Arity -> Type -> TcM ([Type], Type)
    tcInstInvisibleTyBindersN Arity
    n_to_inst Type
    kind
           ; (Type, Type) -> TcM (Type, Type)
    forall (m :: * -> *) a. Monad m => a -> m a
    return (Type
    ty Type -> [Type] -> Type
    `mkTcAppTys` [Type]
    extra_args, Type
    ki') }
      | Bool
    otherwise
      = (Type, Type) -> TcM (Type, Type)
    forall (m :: * -> *) a. Monad m => a -> m a
    return (Type
    ty, Type
    kind)

    {- Note [saturateFamApp]
    ~~~~~~~~~~~~~~~~~~~~~~~~
    Consider
       type family F :: Either j k
       type instance F @Type = Right Maybe
       type instance F @Type = Right Either```

    Then F :: forall {j,k}. Either j k

    The two type instances do a visible kind application that instantiates
    'j' but not 'k'.  But we want to end up with instances that look like
      type instance F @Type @(*->*) = Right @Type @(*->*) Maybe

    so that F has arity 2.  We must instantiate that trailing invisible
    binder. In general, Invisible binders precede Specified and Required,
    so this is only going to bite for apparently-nullary families.

    Note that
      type family F2 :: forall k. k -> *
    is quite different and really does have arity 0.

    It's not just type instances where we need to saturate those
    unsaturated arguments: see #11246.  Hence doing this in tcInferApps.
    -}

    appTypeToArg :: LHsType GhcRn -> [LHsTypeArg GhcRn] -> LHsType GhcRn
    appTypeToArg :: LHsType GhcRn -> HsTyPats GhcRn -> LHsType GhcRn
    appTypeToArg LHsType GhcRn
    f []                       = LHsType GhcRn
    f
    appTypeToArg LHsType GhcRn
    f (HsValArg LHsType GhcRn
    arg    : HsTyPats GhcRn
    args) = LHsType GhcRn -> HsTyPats GhcRn -> LHsType GhcRn
    appTypeToArg (LHsType GhcRn -> LHsType GhcRn -> LHsType GhcRn
    forall (p :: Pass).
    LHsType (GhcPass p) -> LHsType (GhcPass p) -> LHsType (GhcPass p)
    mkHsAppTy LHsType GhcRn
    f LHsType GhcRn
    arg) HsTyPats GhcRn
    args
    appTypeToArg LHsType GhcRn
    f (HsArgPar SrcSpan
    _      : HsTyPats GhcRn
    args) = LHsType GhcRn -> HsTyPats GhcRn -> LHsType GhcRn
    appTypeToArg LHsType GhcRn
    f                 HsTyPats GhcRn
    args
    appTypeToArg LHsType GhcRn
    f (HsTypeArg SrcSpan
    l LHsType GhcRn
    arg : HsTyPats GhcRn
    args)
      = LHsType GhcRn -> HsTyPats GhcRn -> LHsType GhcRn
    appTypeToArg (XAppKindTy GhcRn -> LHsType GhcRn -> LHsType GhcRn -> LHsType GhcRn
    forall (p :: Pass).
    XAppKindTy (GhcPass p)
    -> LHsType (GhcPass p)
    -> LHsType (GhcPass p)
    -> LHsType (GhcPass p)
    mkHsAppKindTy SrcSpan
    XAppKindTy GhcRn
    l LHsType GhcRn
    f LHsType GhcRn
    arg) HsTyPats GhcRn
    args

    {- *********************************************************************
    *                                                                      *
                    checkExpectedKind
    *                                                                      *
    ********************************************************************* -}

    -- | This instantiates invisible arguments for the type being checked if it must
    -- be saturated and is not yet saturated. It then calls and uses the result
    -- from checkExpectedKindX to build the final type
    checkExpectedKind :: HasDebugCallStack
                      => HsType GhcRn       -- ^ type we're checking (for printing)
                      -> TcType             -- ^ type we're checking
                      -> TcKind             -- ^ the known kind of that type
                      -> TcKind             -- ^ the expected kind
                      -> TcM TcType
    -- Just a convenience wrapper to save calls to 'ppr'
    checkExpectedKind :: HasDebugCallStack =>
    HsType GhcRn -> Type -> Type -> Type -> TcM Type
    checkExpectedKind HsType GhcRn
    hs_ty Type
    ty Type
    act_kind Type
    exp_kind
      = do { String -> SDoc -> TcM ()
    traceTc String
    "checkExpectedKind" (Type -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr Type
    ty SDoc -> SDoc -> SDoc
    $$ Type -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr Type
    act_kind)

           ; ([Type]
    new_args, Type
    act_kind') <- Arity -> Type -> TcM ([Type], Type)
    tcInstInvisibleTyBindersN Arity
    n_to_inst Type
    act_kind

           ; let origin :: CtOrigin
    origin = TypeEqOrigin { uo_actual :: Type
    uo_actual   = Type
    act_kind'
                                       , uo_expected :: Type
    uo_expected = Type
    exp_kind
                                       , uo_thing :: Maybe SDoc
    uo_thing    = SDoc -> Maybe SDoc
    forall a. a -> Maybe a
    Just (HsType GhcRn -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr HsType GhcRn
    hs_ty)
                                       , uo_visible :: Bool
    uo_visible  = Bool
    True } -- the hs_ty is visible

           ; String -> SDoc -> TcM ()
    traceTc String
    "checkExpectedKindX" (SDoc -> TcM ()) -> SDoc -> TcM ()
    forall a b. (a -> b) -> a -> b
    $
             [SDoc] -> SDoc
    vcat [ HsType GhcRn -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr HsType GhcRn
    hs_ty
                  , String -> SDoc
    text String
    "act_kind':" SDoc -> SDoc -> SDoc
    <+> Type -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr Type
    act_kind'
                  , String -> SDoc
    text String
    "exp_kind:" SDoc -> SDoc -> SDoc
    <+> Type -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr Type
    exp_kind ]

           ; let res_ty :: Type
    res_ty = Type
    ty Type -> [Type] -> Type
    `mkTcAppTys` [Type]
    new_args

           ; if Type
    act_kind' HasDebugCallStack => Type -> Type -> Bool
    Type -> Type -> Bool
    `tcEqType` Type
    exp_kind
             then Type -> TcM Type
    forall (m :: * -> *) a. Monad m => a -> m a
    return Type
    res_ty  -- This is very common
             else do { Coercion
    co_k <- TypeOrKind -> CtOrigin -> Type -> Type -> TcM Coercion
    uType TypeOrKind
    KindLevel CtOrigin
    origin Type
    act_kind' Type
    exp_kind
                     ; String -> SDoc -> TcM ()
    traceTc String
    "checkExpectedKind" ([SDoc] -> SDoc
    vcat [ Type -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr Type
    act_kind
                                                         , Type -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr Type
    exp_kind
                                                         , Coercion -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr Coercion
    co_k ])
                    ; Type -> TcM Type
    forall (m :: * -> *) a. Monad m => a -> m a
    return (Type
    res_ty Type -> Coercion -> Type
    `mkTcCastTy` Coercion
    co_k) } }
        where
          -- We need to make sure that both kinds have the same number of implicit
          -- foralls out front. If the actual kind has more, instantiate accordingly.
          -- Otherwise, just pass the type & kind through: the errors are caught
          -- in unifyType.
          n_exp_invis_bndrs :: Arity
    n_exp_invis_bndrs = Type -> Arity
    invisibleTyBndrCount Type
    exp_kind
          n_act_invis_bndrs :: Arity
    n_act_invis_bndrs = Type -> Arity
    invisibleTyBndrCount Type
    act_kind
          n_to_inst :: Arity
    n_to_inst         = Arity
    n_act_invis_bndrs Arity -> Arity -> Arity
    forall a. Num a => a -> a -> a
    - Arity
    n_exp_invis_bndrs

    ---------------------------

    tcHsContext :: Maybe (LHsContext GhcRn) -> TcM [PredType]
    tcHsContext :: Maybe (LHsContext GhcRn) -> TcM [Type]
    tcHsContext Maybe (LHsContext GhcRn)
    cxt = TcTyMode -> Maybe (LHsContext GhcRn) -> TcM [Type]
    tc_hs_context TcTyMode
    typeLevelMode Maybe (LHsContext GhcRn)
    cxt

    tcLHsPredType :: LHsType GhcRn -> TcM PredType
    tcLHsPredType :: LHsType GhcRn -> TcM Type
    tcLHsPredType LHsType GhcRn
    pred = TcTyMode -> LHsType GhcRn -> TcM Type
    tc_lhs_pred TcTyMode
    typeLevelMode LHsType GhcRn
    pred

    tc_hs_context :: TcTyMode -> Maybe (LHsContext GhcRn) -> TcM [PredType]
    tc_hs_context :: TcTyMode -> Maybe (LHsContext GhcRn) -> TcM [Type]
    tc_hs_context TcTyMode
    _ Maybe (LHsContext GhcRn)
    Nothing = [Type] -> TcM [Type]
    forall (m :: * -> *) a. Monad m => a -> m a
    return []
    tc_hs_context TcTyMode
    mode (Just LHsContext GhcRn
    ctxt) = (GenLocated SrcSpanAnnA (HsType GhcRn) -> TcM Type)
    -> [GenLocated SrcSpanAnnA (HsType GhcRn)] -> TcM [Type]
    forall (t :: * -> *) (m :: * -> *) a b.
    (Traversable t, Monad m) =>
    (a -> m b) -> t a -> m (t b)
    mapM (TcTyMode -> LHsType GhcRn -> TcM Type
    tc_lhs_pred TcTyMode
    mode) (GenLocated SrcSpanAnnC [GenLocated SrcSpanAnnA (HsType GhcRn)]
    -> [GenLocated SrcSpanAnnA (HsType GhcRn)]
    forall l e. GenLocated l e -> e
    unLoc GenLocated SrcSpanAnnC [GenLocated SrcSpanAnnA (HsType GhcRn)]
    LHsContext GhcRn
    ctxt)

    tc_lhs_pred :: TcTyMode -> LHsType GhcRn -> TcM PredType
    tc_lhs_pred :: TcTyMode -> LHsType GhcRn -> TcM Type
    tc_lhs_pred TcTyMode
    mode LHsType GhcRn
    pred = TcTyMode -> LHsType GhcRn -> Type -> TcM Type
    tc_lhs_type TcTyMode
    mode LHsType GhcRn
    pred Type
    constraintKind

    ---------------------------
    tcTyVar :: TcTyMode -> Name -> TcM (TcType, TcKind)
    -- See Note [Type checking recursive type and class declarations]
    -- in GHC.Tc.TyCl
    -- This does not instantiate. See Note [Do not always instantiate eagerly in types]
    tcTyVar :: TcTyMode -> Name -> TcM (Type, Type)
    tcTyVar TcTyMode
    mode Name
    name         -- Could be a tyvar, a tycon, or a datacon
      = do { String -> SDoc -> TcM ()
    traceTc String
    "lk1" (Name -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr Name
    name)
           ; TcTyThing
    thing <- Name -> TcM TcTyThing
    tcLookup Name
    name
           ; case TcTyThing
    thing of
               ATyVar Name
    _ TyVar
    tv -> (Type, Type) -> TcM (Type, Type)
    forall (m :: * -> *) a. Monad m => a -> m a
    return (TyVar -> Type
    mkTyVarTy TyVar
    tv, TyVar -> Type
    tyVarKind TyVar
    tv)

               -- See Note [Recursion through the kinds]
               ATcTyCon TyCon
    tc_tc
                 -> do { TyCon -> TcM ()
    check_tc TyCon
    tc_tc
                       ; (Type, Type) -> TcM (Type, Type)
    forall (m :: * -> *) a. Monad m => a -> m a
    return (TyCon -> Type
    mkTyConTy TyCon
    tc_tc, TyCon -> Type
    tyConKind TyCon
    tc_tc) }

               AGlobal (ATyCon TyCon
    tc)
                 -> do { TyCon -> TcM ()
    check_tc TyCon
    tc
                       ; (Type, Type) -> TcM (Type, Type)
    forall (m :: * -> *) a. Monad m => a -> m a
    return (TyCon -> Type
    mkTyConTy TyCon
    tc, TyCon -> Type
    tyConKind TyCon
    tc) }

               AGlobal (AConLike (RealDataCon DataCon
    dc))
                 -> do { Bool
    data_kinds <- Extension -> TcRnIf TcGblEnv TcLclEnv Bool
    forall gbl lcl. Extension -> TcRnIf gbl lcl Bool
    xoptM Extension
    LangExt.DataKinds
                       ; Bool -> TcM () -> TcM ()
    forall (f :: * -> *). Applicative f => Bool -> f () -> f ()
    unless (Bool
    data_kinds Bool -> Bool -> Bool
    || DataCon -> Bool
    specialPromotedDc DataCon
    dc) (TcM () -> TcM ()) -> TcM () -> TcM ()
    forall a b. (a -> b) -> a -> b
    $
                           Name -> PromotionErr -> TcM ()
    forall a. Name -> PromotionErr -> TcM a
    promotionErr Name
    name PromotionErr
    NoDataKindsDC
                       ; Bool -> TcM () -> TcM ()
    forall (f :: * -> *). Applicative f => Bool -> f () -> f ()
    when (TyCon -> Bool
    isFamInstTyCon (DataCon -> TyCon
    dataConTyCon DataCon
    dc)) (TcM () -> TcM ()) -> TcM () -> TcM ()
    forall a b. (a -> b) -> a -> b
    $
                           -- see #15245
                           Name -> PromotionErr -> TcM ()
    forall a. Name -> PromotionErr -> TcM a
    promotionErr Name
    name PromotionErr
    FamDataConPE
                       ; let ([TyVar]
    _, [TyVar]
    _, [EqSpec]
    _, [Type]
    theta, [Scaled Type]
    _, Type
    _) = DataCon
    -> ([TyVar], [TyVar], [EqSpec], [Type], [Scaled Type], Type)
    dataConFullSig DataCon
    dc
                       ; String -> SDoc -> TcM ()
    traceTc String
    "tcTyVar" (DataCon -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr DataCon
    dc SDoc -> SDoc -> SDoc
    <+> [Type] -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr [Type]
    theta SDoc -> SDoc -> SDoc
    $$ Maybe Type -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr ([Type] -> Maybe Type
    dc_theta_illegal_constraint [Type]
    theta))
                       ; case [Type] -> Maybe Type
    dc_theta_illegal_constraint [Type]
    theta of
                           Just Type
    pred -> Name -> PromotionErr -> TcM ()
    forall a. Name -> PromotionErr -> TcM a
    promotionErr Name
    name (PromotionErr -> TcM ()) -> PromotionErr -> TcM ()
    forall a b. (a -> b) -> a -> b
    $
                                        Type -> PromotionErr
    ConstrainedDataConPE Type
    pred
                           Maybe Type
    Nothing   -> () -> TcM ()
    forall (f :: * -> *) a. Applicative f => a -> f a
    pure ()
                       ; let tc :: TyCon
    tc = DataCon -> TyCon
    promoteDataCon DataCon
    dc
                       ; (Type, Type) -> TcM (Type, Type)
    forall (m :: * -> *) a. Monad m => a -> m a
    return (TyCon -> [Type] -> Type
    mkTyConApp TyCon
    tc [], TyCon -> Type
    tyConKind TyCon
    tc) }

               APromotionErr PromotionErr
    err -> Name -> PromotionErr -> TcM (Type, Type)
    forall a. Name -> PromotionErr -> TcM a
    promotionErr Name
    name PromotionErr
    err

               TcTyThing
    _  -> String -> TcTyThing -> Name -> TcM (Type, Type)
    forall a. String -> TcTyThing -> Name -> TcM a
    wrongThingErr String
    "type" TcTyThing
    thing Name
    name }
      where
        check_tc :: TyCon -> TcM ()
        check_tc :: TyCon -> TcM ()
    check_tc TyCon
    tc = do { Bool
    data_kinds   <- Extension -> TcRnIf TcGblEnv TcLclEnv Bool
    forall gbl lcl. Extension -> TcRnIf gbl lcl Bool
    xoptM Extension
    LangExt.DataKinds
                         ; Bool -> TcM () -> TcM ()
    forall (f :: * -> *). Applicative f => Bool -> f () -> f ()
    unless (TypeOrKind -> Bool
    isTypeLevel (TcTyMode -> TypeOrKind
    mode_tyki TcTyMode
    mode) Bool -> Bool -> Bool
    ||
                                   Bool
    data_kinds Bool -> Bool -> Bool
    ||
                                   TyCon -> Bool
    isKindTyCon TyCon
    tc) (TcM () -> TcM ()) -> TcM () -> TcM ()
    forall a b. (a -> b) -> a -> b
    $
                           Name -> PromotionErr -> TcM ()
    forall a. Name -> PromotionErr -> TcM a
    promotionErr Name
    name PromotionErr
    NoDataKindsTC }

        -- We cannot promote a data constructor with a context that contains
        -- constraints other than equalities, so error if we find one.
        -- See Note [Constraints in kinds] in GHC.Core.TyCo.Rep
        dc_theta_illegal_constraint :: ThetaType -> Maybe PredType
        dc_theta_illegal_constraint :: [Type] -> Maybe Type
    dc_theta_illegal_constraint = (Type -> Bool) -> [Type] -> Maybe Type
    forall (t :: * -> *) a. Foldable t => (a -> Bool) -> t a -> Maybe a
    find (Bool -> Bool
    not (Bool -> Bool) -> (Type -> Bool) -> Type -> Bool
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . Type -> Bool
    isEqPred)

    {-
    Note [Recursion through the kinds]
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    Consider these examples

    Ticket #11554:
      data P (x :: k) = Q
      data A :: Type where
        MkA :: forall (a :: A). P a -> A

    Ticket #12174
      data V a
      data T = forall (a :: T). MkT (V a)

    The type is recursive (which is fine) but it is recursive /through the
    kinds/.  In earlier versions of GHC this caused a loop in the compiler
    (to do with knot-tying) but there is nothing fundamentally wrong with
    the code (kinds are types, and the recursive declarations are OK). But
    it's hard to distinguish "recursion through the kinds" from "recursion
    through the types". Consider this (also #11554):

      data PB k (x :: k) = Q
      data B :: Type where
        MkB :: P B a -> B

    Here the occurrence of B is not obviously in a kind position.

    So now GHC allows all these programs.  #12081 and #15942 are other
    examples.

    Note [Body kind of a HsForAllTy]
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    The body of a forall is usually a type, but in principle
    there's no reason to prohibit *unlifted* types.
    In fact, GHC can itself construct a function with an
    unboxed tuple inside a for-all (via CPR analysis; see
    typecheck/should_compile/tc170).

    Moreover in instance heads we get forall-types with
    kind Constraint.

    It's tempting to check that the body kind is either * or #. But this is
    wrong. For example:

      class C a b
      newtype N = Mk Foo deriving (C a)

    We're doing newtype-deriving for C. But notice how `a` isn't in scope in
    the predicate `C a`. So we quantify, yielding `forall a. C a` even though
    `C a` has kind `* -> Constraint`. The `forall a. C a` is a bit cheeky, but
    convenient. Bottom line: don't check for * or # here.

    Note [Body kind of a HsQualTy]
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    If ctxt is non-empty, the HsQualTy really is a /function/, so the
    kind of the result really is '*', and in that case the kind of the
    body-type can be lifted or unlifted.

    However, consider
        instance Eq a => Eq [a] where ...
    or
        f :: (Eq a => Eq [a]) => blah
    Here both body-kind of the HsQualTy is Constraint rather than *.
    Rather crudely we tell the difference by looking at exp_kind. It's
    very convenient to typecheck instance types like any other HsSigType.

    Admittedly the '(Eq a => Eq [a]) => blah' case is erroneous, but it's
    better to reject in checkValidType.  If we say that the body kind
    should be '*' we risk getting TWO error messages, one saying that Eq
    [a] doesn't have kind '*', and one saying that we need a Constraint to
    the left of the outer (=>).

    How do we figure out the right body kind?  Well, it's a bit of a
    kludge: I just look at the expected kind.  If it's Constraint, we
    must be in this instance situation context. It's a kludge because it
    wouldn't work if any unification was involved to compute that result
    kind -- but it isn't.  (The true way might be to use the 'mode'
    parameter, but that seemed like a sledgehammer to crack a nut.)

    Note [Inferring tuple kinds]
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    Give a tuple type (a,b,c), which the parser labels as HsBoxedOrConstraintTuple,
    we try to figure out whether it's a tuple of kind * or Constraint.
      Step 1: look at the expected kind
      Step 2: infer argument kinds

    If after Step 2 it's not clear from the arguments that it's
    Constraint, then it must be *.  Once having decided that we re-check
    the arguments to give good error messages in
      e.g.  (Maybe, Maybe)

    Note that we will still fail to infer the correct kind in this case:

      type T a = ((a,a), D a)
      type family D :: Constraint -> Constraint

    While kind checking T, we do not yet know the kind of D, so we will default the
    kind of T to * -> *. It works if we annotate `a` with kind `Constraint`.

    Note [Desugaring types]
    ~~~~~~~~~~~~~~~~~~~~~~~
    The type desugarer is phase 2 of dealing with HsTypes.  Specifically:

      * It transforms from HsType to Type

      * It zonks any kinds.  The returned type should have no mutable kind
        or type variables (hence returning Type not TcType):
          - any unconstrained kind variables are defaulted to (Any *) just
            as in GHC.Tc.Utils.Zonk.
          - there are no mutable type variables because we are
            kind-checking a type
        Reason: the returned type may be put in a TyCon or DataCon where
        it will never subsequently be zonked.

    You might worry about nested scopes:
            ..a:kappa in scope..
                let f :: forall b. T '[a,b] -> Int
    In this case, f's type could have a mutable kind variable kappa in it;
    and we might then default it to (Any *) when dealing with f's type
    signature.  But we don't expect this to happen because we can't get a
    lexically scoped type variable with a mutable kind variable in it.  A
    delicate point, this.  If it becomes an issue we might need to
    distinguish top-level from nested uses.

    Moreover
      * it cannot fail,
      * it does no unifications
      * it does no validity checking, except for structural matters, such as
            (a) spurious ! annotations.
            (b) a class used as a type

    Note [Kind of a type splice]
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    Consider these terms, each with TH type splice inside:
         [| e1 :: Maybe $(..blah..) |]
         [| e2 :: $(..blah..) |]
    When kind-checking the type signature, we'll kind-check the splice
    $(..blah..); we want to give it a kind that can fit in any context,
    as if $(..blah..) :: forall k. k.

    In the e1 example, the context of the splice fixes kappa to *.  But
    in the e2 example, we'll desugar the type, zonking the kind unification
    variables as we go.  When we encounter the unconstrained kappa, we
    want to default it to '*', not to (Any *).

    -}

    addTypeCtxt :: LHsType GhcRn -> TcM a -> TcM a
            -- Wrap a context around only if we want to show that contexts.
            -- Omit invisible ones and ones user's won't grok
    addTypeCtxt :: forall a. LHsType GhcRn -> TcM a -> TcM a
    addTypeCtxt (L SrcSpanAnnA
    _ (HsWildCardTy XWildCardTy GhcRn
    _)) TcM a
    thing = TcM a
    thing   -- "In the type '_'" just isn't helpful.
    addTypeCtxt (L SrcSpanAnnA
    _ HsType GhcRn
    ty) TcM a
    thing
      = SDoc -> TcM a -> TcM a
    forall a. SDoc -> TcM a -> TcM a
    addErrCtxt SDoc
    doc TcM a
    thing
      where
        doc :: SDoc
    doc = String -> SDoc
    text String
    "In the type" SDoc -> SDoc -> SDoc
    <+> SDoc -> SDoc
    quotes (HsType GhcRn -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr HsType GhcRn
    ty)

    {- *********************************************************************
    *                                                                      *
                    Type-variable binders
    *                                                                      *
    ********************************************************************* -}

    bindNamedWildCardBinders :: [Name]
                             -> ([(Name, TcTyVar)] -> TcM a)
                             -> TcM a
    -- Bring into scope the /named/ wildcard binders.  Remember that
    -- plain wildcards _ are anonymous and dealt with by HsWildCardTy
    -- Soe Note [The wildcard story for types] in GHC.Hs.Type
    bindNamedWildCardBinders :: forall a. HsQTvsRn -> ([(Name, TyVar)] -> TcM a) -> TcM a
    bindNamedWildCardBinders HsQTvsRn
    wc_names [(Name, TyVar)] -> TcM a
    thing_inside
      = do { [TyVar]
    wcs <- (Name -> IOEnv (Env TcGblEnv TcLclEnv) TyVar)
    -> HsQTvsRn -> TcM [TyVar]
    forall (t :: * -> *) (m :: * -> *) a b.
    (Traversable t, Monad m) =>
    (a -> m b) -> t a -> m (t b)
    mapM Name -> IOEnv (Env TcGblEnv TcLclEnv) TyVar
    newNamedWildTyVar HsQTvsRn
    wc_names
           ; let wc_prs :: [(Name, TyVar)]
    wc_prs = HsQTvsRn
    wc_names HsQTvsRn -> [TyVar] -> [(Name, TyVar)]
    forall a b. [a] -> [b] -> [(a, b)]
    `zip` [TyVar]
    wcs
           ; [(Name, TyVar)] -> TcM a -> TcM a
    forall r. [(Name, TyVar)] -> TcM r -> TcM r
    tcExtendNameTyVarEnv [(Name, TyVar)]
    wc_prs (TcM a -> TcM a) -> TcM a -> TcM a
    forall a b. (a -> b) -> a -> b
    $
             [(Name, TyVar)] -> TcM a
    thing_inside [(Name, TyVar)]
    wc_prs }

    newNamedWildTyVar :: Name -> TcM TcTyVar
    -- ^ New unification variable '_' for a wildcard
    newNamedWildTyVar :: Name -> IOEnv (Env TcGblEnv TcLclEnv) TyVar
    newNamedWildTyVar Name
    _name   -- Currently ignoring the "_x" wildcard name used in the type
      = do { Type
    kind <- TcM Type
    newMetaKindVar
           ; TcTyVarDetails
    details <- MetaInfo -> TcM TcTyVarDetails
    newMetaDetails MetaInfo
    TauTv
           ; Name
    wc_name <- FastString -> TcM Name
    newMetaTyVarName (String -> FastString
    fsLit String
    "w")   -- See Note [Wildcard names]
           ; let tyvar :: TyVar
    tyvar = Name -> Type -> TcTyVarDetails -> TyVar
    mkTcTyVar Name
    wc_name Type
    kind TcTyVarDetails
    details
           ; String -> SDoc -> TcM ()
    traceTc String
    "newWildTyVar" (TyVar -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr TyVar
    tyvar)
           ; TyVar -> IOEnv (Env TcGblEnv TcLclEnv) TyVar
    forall (m :: * -> *) a. Monad m => a -> m a
    return TyVar
    tyvar }

    ---------------------------
    tcAnonWildCardOcc :: IsExtraConstraint
                      -> TcTyMode -> HsType GhcRn -> Kind -> TcM TcType
    tcAnonWildCardOcc :: IsExtraConstraint -> TcTyMode -> HsType GhcRn -> Type -> TcM Type
    tcAnonWildCardOcc IsExtraConstraint
    is_extra (TcTyMode { mode_holes :: TcTyMode -> HoleInfo
    mode_holes = Just (TcLevel
    hole_lvl, HoleMode
    hole_mode) })
                      HsType GhcRn
    ty Type
    exp_kind
        -- hole_lvl: see Note [Checking partial type signatures]
        --           esp the bullet on nested forall types
      = do { TcTyVarDetails
    kv_details <- TcLevel -> TcM TcTyVarDetails
    newTauTvDetailsAtLevel TcLevel
    hole_lvl
           ; Name
    kv_name    <- FastString -> TcM Name
    newMetaTyVarName (String -> FastString
    fsLit String
    "k")
           ; TcTyVarDetails
    wc_details <- TcLevel -> TcM TcTyVarDetails
    newTauTvDetailsAtLevel TcLevel
    hole_lvl
           ; Name
    wc_name    <- FastString -> TcM Name
    newMetaTyVarName (String -> FastString
    fsLit String
    wc_nm)
           ; let kv :: TyVar
    kv      = Name -> Type -> TcTyVarDetails -> TyVar
    mkTcTyVar Name
    kv_name Type
    liftedTypeKind TcTyVarDetails
    kv_details
                 wc_kind :: Type
    wc_kind = TyVar -> Type
    mkTyVarTy TyVar
    kv
                 wc_tv :: TyVar
    wc_tv   = Name -> Type -> TcTyVarDetails -> TyVar
    mkTcTyVar Name
    wc_name Type
    wc_kind TcTyVarDetails
    wc_details

           ; String -> SDoc -> TcM ()
    traceTc String
    "tcAnonWildCardOcc" (TcLevel -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr TcLevel
    hole_lvl SDoc -> SDoc -> SDoc
    <+> Bool -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr Bool
    emit_holes)
           ; Bool -> TcM () -> TcM ()
    forall (f :: * -> *). Applicative f => Bool -> f () -> f ()
    when Bool
    emit_holes (TcM () -> TcM ()) -> TcM () -> TcM ()
    forall a b. (a -> b) -> a -> b
    $
             IsExtraConstraint -> TyVar -> TcM ()
    emitAnonTypeHole IsExtraConstraint
    is_extra TyVar
    wc_tv
             -- Why the 'when' guard?
             -- See Note [Wildcards in visible kind application]

           -- You might think that this would always just unify
           -- wc_kind with exp_kind, so we could avoid even creating kv
           -- But the level numbers might not allow that unification,
           -- so we have to do it properly (T14140a)
           ; HasDebugCallStack =>
    HsType GhcRn -> Type -> Type -> Type -> TcM Type
    HsType GhcRn -> Type -> Type -> Type -> TcM Type
    checkExpectedKind HsType GhcRn
    ty (TyVar -> Type
    mkTyVarTy TyVar
    wc_tv) Type
    wc_kind Type
    exp_kind }
      where
         -- See Note [Wildcard names]
         wc_nm :: String
    wc_nm = case HoleMode
    hole_mode of
                   HoleMode
    HM_Sig      -> String
    "w"
                   HoleMode
    HM_FamPat   -> String
    "_"
                   HoleMode
    HM_VTA      -> String
    "w"
                   HoleMode
    HM_TyAppPat -> String
    "_"

         emit_holes :: Bool
    emit_holes = case HoleMode
    hole_mode of
                         HoleMode
    HM_Sig     -> Bool
    True
                         HoleMode
    HM_FamPat  -> Bool
    False
                         HoleMode
    HM_VTA     -> Bool
    False
                         HoleMode
    HM_TyAppPat -> Bool
    False

    tcAnonWildCardOcc IsExtraConstraint
    _ TcTyMode
    mode HsType GhcRn
    ty Type
    _
    -- mode_holes is Nothing.  Should not happen, because renamer
    -- should already have rejected holes in unexpected places
      = String -> SDoc -> TcM Type
    forall a. HasCallStack => String -> SDoc -> a
    pprPanic String
    "tcWildCardOcc" (TcTyMode -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr TcTyMode
    mode SDoc -> SDoc -> SDoc
    $$ HsType GhcRn -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr HsType GhcRn
    ty)

    {- Note [Wildcard names]
    ~~~~~~~~~~~~~~~~~~~~~~~~
    So we hackily use the mode_holes flag to control the name used
    for wildcards:

    * For proper holes (whether in a visible type application (VTA) or no),
      we rename the '_' to 'w'. This is so that we see variables like 'w0'
      or 'w1' in error messages, a vast improvement upon '_0' and '_1'. For
      example, we prefer
           Found type wildcard ‘_’ standing for ‘w0’
      over
           Found type wildcard ‘_’ standing for ‘_1’

      Even in the VTA case, where we do not emit an error to be printed, we
      want to do the renaming, as the variables may appear in other,
      non-wildcard error messages.

    * However, holes in the left-hand sides of type families ("type
      patterns") stand for type variables which we do not care to name --
      much like the use of an underscore in an ordinary term-level
      pattern. When we spot these, we neither wish to generate an error
      message nor to rename the variable.  We don't rename the variable so
      that we can pretty-print a type family LHS as, e.g.,
        F _ Int _ = ...
      and not
         F w1 Int w2 = ...

      See also Note [Wildcards in family instances] in
      GHC.Rename.Module. The choice of HM_FamPat is made in
      tcFamTyPats. There is also some unsavory magic, relying on that
      underscore, in GHC.Core.Coercion.tidyCoAxBndrsForUser.

    Note [Wildcards in visible kind application]
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    There are cases where users might want to pass in a wildcard as a visible kind
    argument, for instance:

    data T :: forall k1 k2. k1 → k2 → Type where
      MkT :: T a b
    x :: T @_ @Nat False n
    x = MkT

    So we should allow '@_' without emitting any hole constraints, and
    regardless of whether PartialTypeSignatures is enabled or not. But how
    would the typechecker know which '_' is being used in VKA and which is
    not when it calls emitNamedTypeHole in
    tcHsPartialSigType on all HsWildCardBndrs?  The solution is to neither
    rename nor include unnamed wildcards in HsWildCardBndrs, but instead
    give every anonymous wildcard a fresh wild tyvar in tcAnonWildCardOcc.

    And whenever we see a '@', we set mode_holes to HM_VKA, so that
    we do not call emitAnonTypeHole in tcAnonWildCardOcc.
    See related Note [Wildcards in visible type application] here and
    Note [The wildcard story for types] in GHC.Hs.Type
    -}

    {- *********************************************************************
    *                                                                      *
                 Kind inference for type declarations
    *                                                                      *
    ********************************************************************* -}

    -- See Note [kcCheckDeclHeader vs kcInferDeclHeader]
    data InitialKindStrategy
      = InitialKindCheck SAKS_or_CUSK
      | InitialKindInfer

    -- Does the declaration have a standalone kind signature (SAKS) or a complete
    -- user-specified kind (CUSK)?
    data SAKS_or_CUSK
      = SAKS Kind  -- Standalone kind signature, fully zonked! (zonkTcTypeToType)
      | CUSK       -- Complete user-specified kind (CUSK)

    instance Outputable SAKS_or_CUSK where
      ppr :: SAKS_or_CUSK -> SDoc
    ppr (SAKS Type
    k) = String -> SDoc
    text String
    "SAKS" SDoc -> SDoc -> SDoc
    <+> Type -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr Type
    k
      ppr SAKS_or_CUSK
    CUSK = String -> SDoc
    text String
    "CUSK"

    -- See Note [kcCheckDeclHeader vs kcInferDeclHeader]
    kcDeclHeader
      :: InitialKindStrategy
      -> Name              -- ^ of the thing being checked
      -> TyConFlavour      -- ^ What sort of 'TyCon' is being checked
      -> LHsQTyVars GhcRn  -- ^ Binders in the header
      -> TcM ContextKind   -- ^ The result kind
      -> TcM TcTyCon       -- ^ A suitably-kinded TcTyCon
    kcDeclHeader :: InitialKindStrategy
    -> Name
    -> TyConFlavour
    -> LHsQTyVars GhcRn
    -> TcM ContextKind
    -> TcM TyCon
    kcDeclHeader (InitialKindCheck SAKS_or_CUSK
    msig) = SAKS_or_CUSK
    -> Name
    -> TyConFlavour
    -> LHsQTyVars GhcRn
    -> TcM ContextKind
    -> TcM TyCon
    kcCheckDeclHeader SAKS_or_CUSK
    msig
    kcDeclHeader InitialKindStrategy
    InitialKindInfer = Name
    -> TyConFlavour -> LHsQTyVars GhcRn -> TcM ContextKind -> TcM TyCon
    kcInferDeclHeader

    {- Note [kcCheckDeclHeader vs kcInferDeclHeader]
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    kcCheckDeclHeader and kcInferDeclHeader are responsible for getting the initial kind
    of a type constructor.

    * kcCheckDeclHeader: the TyCon has a standalone kind signature or a CUSK. In that
      case, find the full, final, poly-kinded kind of the TyCon.  It's very like a
      term-level binding where we have a complete type signature for the function.

    * kcInferDeclHeader: the TyCon has neither a standalone kind signature nor a
      CUSK. Find a monomorphic kind, with unification variables in it; they will be
      generalised later.  It's very like a term-level binding where we do not have a
      type signature (or, more accurately, where we have a partial type signature),
      so we infer the type and generalise.
    -}

    ------------------------------
    kcCheckDeclHeader
      :: SAKS_or_CUSK
      -> Name              -- ^ of the thing being checked
      -> TyConFlavour      -- ^ What sort of 'TyCon' is being checked
      -> LHsQTyVars GhcRn  -- ^ Binders in the header
      -> TcM ContextKind   -- ^ The result kind. AnyKind == no result signature
      -> TcM TcTyCon       -- ^ A suitably-kinded generalized TcTyCon
    kcCheckDeclHeader :: SAKS_or_CUSK
    -> Name
    -> TyConFlavour
    -> LHsQTyVars GhcRn
    -> TcM ContextKind
    -> TcM TyCon
    kcCheckDeclHeader (SAKS Type
    sig) = Type
    -> Name
    -> TyConFlavour
    -> LHsQTyVars GhcRn
    -> TcM ContextKind
    -> TcM TyCon
    kcCheckDeclHeader_sig Type
    sig
    kcCheckDeclHeader SAKS_or_CUSK
    CUSK       = Name
    -> TyConFlavour -> LHsQTyVars GhcRn -> TcM ContextKind -> TcM TyCon
    kcCheckDeclHeader_cusk

    kcCheckDeclHeader_cusk
      :: Name              -- ^ of the thing being checked
      -> TyConFlavour      -- ^ What sort of 'TyCon' is being checked
      -> LHsQTyVars GhcRn  -- ^ Binders in the header
      -> TcM ContextKind   -- ^ The result kind
      -> TcM TcTyCon       -- ^ A suitably-kinded generalized TcTyCon
    kcCheckDeclHeader_cusk :: Name
    -> TyConFlavour -> LHsQTyVars GhcRn -> TcM ContextKind -> TcM TyCon
    kcCheckDeclHeader_cusk Name
    name TyConFlavour
    flav
                  (HsQTvs { hsq_ext :: forall pass. LHsQTyVars pass -> XHsQTvs pass
    hsq_ext = XHsQTvs GhcRn
    kv_ns
                          , hsq_explicit :: forall pass. LHsQTyVars pass -> [LHsTyVarBndr () pass]
    hsq_explicit = [LHsTyVarBndr () GhcRn]
    hs_tvs }) TcM ContextKind
    kc_res_ki
      -- CUSK case
      -- See note [Required, Specified, and Inferred for types] in GHC.Tc.TyCl
      = Name -> TyConFlavour -> TcM TyCon -> TcM TyCon
    forall a. Name -> TyConFlavour -> TcM a -> TcM a
    addTyConFlavCtxt Name
    name TyConFlavour
    flav (TcM TyCon -> TcM TyCon) -> TcM TyCon -> TcM TyCon
    forall a b. (a -> b) -> a -> b
    $
        do { (TcLevel
    tclvl, WantedConstraints
    wanted, ([TyVar]
    scoped_kvs, ([TyVar]
    tc_tvs, Type
    res_kind)))
               <- String
    -> TcM ([TyVar], ([TyVar], Type))
    -> TcM (TcLevel, WantedConstraints, ([TyVar], ([TyVar], Type)))
    forall a. String -> TcM a -> TcM (TcLevel, WantedConstraints, a)
    pushLevelAndSolveEqualitiesX String
    "kcCheckDeclHeader_cusk" (TcM ([TyVar], ([TyVar], Type))
     -> TcM (TcLevel, WantedConstraints, ([TyVar], ([TyVar], Type))))
    -> TcM ([TyVar], ([TyVar], Type))
    -> TcM (TcLevel, WantedConstraints, ([TyVar], ([TyVar], Type)))
    forall a b. (a -> b) -> a -> b
    $
                  HsQTvsRn -> TcM ([TyVar], Type) -> TcM ([TyVar], ([TyVar], Type))
    forall a. HsQTvsRn -> TcM a -> TcM ([TyVar], a)
    bindImplicitTKBndrs_Q_Skol HsQTvsRn
    XHsQTvs GhcRn
    kv_ns                      (TcM ([TyVar], Type) -> TcM ([TyVar], ([TyVar], Type)))
    -> TcM ([TyVar], Type) -> TcM ([TyVar], ([TyVar], Type))
    forall a b. (a -> b) -> a -> b
    $
                  ContextKind
    -> [LHsTyVarBndr () GhcRn] -> TcM Type -> TcM ([TyVar], Type)
    forall a.
    ContextKind -> [LHsTyVarBndr () GhcRn] -> TcM a -> TcM ([TyVar], a)
    bindExplicitTKBndrs_Q_Skol ContextKind
    ctxt_kind [LHsTyVarBndr () GhcRn]
    hs_tvs           (TcM Type -> TcM ([TyVar], Type))
    -> TcM Type -> TcM ([TyVar], Type)
    forall a b. (a -> b) -> a -> b
    $
                  ContextKind -> TcM Type
    newExpectedKind (ContextKind -> TcM Type) -> TcM ContextKind -> TcM Type
    forall (m :: * -> *) a b. Monad m => (a -> m b) -> m a -> m b
    =<< TcM ContextKind
    kc_res_ki

               -- Now, because we're in a CUSK,
               -- we quantify over the mentioned kind vars
           ; let spec_req_tkvs :: [TyVar]
    spec_req_tkvs = [TyVar]
    scoped_kvs [TyVar] -> [TyVar] -> [TyVar]
    forall a. [a] -> [a] -> [a]
    ++ [TyVar]
    tc_tvs
                 all_kinds :: [Type]
    all_kinds     = Type
    res_kind Type -> [Type] -> [Type]
    forall a. a -> [a] -> [a]
    : (TyVar -> Type) -> [TyVar] -> [Type]
    forall a b. (a -> b) -> [a] -> [b]
    map TyVar -> Type
    tyVarKind [TyVar]
    spec_req_tkvs

           ; CandidatesQTvs
    candidates' <- [Type] -> TcM CandidatesQTvs
    candidateQTyVarsOfKinds [Type]
    all_kinds
                 -- 'candidates' are all the variables that we are going to
                 -- skolemise and then quantify over.  We do not include spec_req_tvs
                 -- because they are /already/ skolems

           ; let non_tc_candidates :: [TyVar]
    non_tc_candidates = (TyVar -> Bool) -> [TyVar] -> [TyVar]
    forall a. (a -> Bool) -> [a] -> [a]
    filter (Bool -> Bool
    not (Bool -> Bool) -> (TyVar -> Bool) -> TyVar -> Bool
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . TyVar -> Bool
    isTcTyVar) (VarSet -> [TyVar]
    forall elt. UniqSet elt -> [elt]
    nonDetEltsUniqSet ([Type] -> VarSet
    tyCoVarsOfTypes [Type]
    all_kinds))
                 candidates :: CandidatesQTvs
    candidates = CandidatesQTvs
    candidates' { dv_kvs :: DTyVarSet
    dv_kvs = CandidatesQTvs -> DTyVarSet
    dv_kvs CandidatesQTvs
    candidates' DTyVarSet -> [TyVar] -> DTyVarSet
    `extendDVarSetList` [TyVar]
    non_tc_candidates }
                 inf_candidates :: CandidatesQTvs
    inf_candidates = CandidatesQTvs
    candidates CandidatesQTvs -> [TyVar] -> CandidatesQTvs
    `delCandidates` [TyVar]
    spec_req_tkvs

           ; [TyVar]
    inferred <- CandidatesQTvs -> TcM [TyVar]
    quantifyTyVars CandidatesQTvs
    inf_candidates
                         -- NB: 'inferred' comes back sorted in dependency order

           ; [TyVar]
    scoped_kvs <- (TyVar -> IOEnv (Env TcGblEnv TcLclEnv) TyVar)
    -> [TyVar] -> TcM [TyVar]
    forall (t :: * -> *) (m :: * -> *) a b.
    (Traversable t, Monad m) =>
    (a -> m b) -> t a -> m (t b)
    mapM TyVar -> IOEnv (Env TcGblEnv TcLclEnv) TyVar
    zonkTyCoVarKind [TyVar]
    scoped_kvs
           ; [TyVar]
    tc_tvs     <- (TyVar -> IOEnv (Env TcGblEnv TcLclEnv) TyVar)
    -> [TyVar] -> TcM [TyVar]
    forall (t :: * -> *) (m :: * -> *) a b.
    (Traversable t, Monad m) =>
    (a -> m b) -> t a -> m (t b)
    mapM TyVar -> IOEnv (Env TcGblEnv TcLclEnv) TyVar
    zonkTyCoVarKind [TyVar]
    tc_tvs
           ; Type
    res_kind   <- Type -> TcM Type
    zonkTcType           Type
    res_kind

           ; let mentioned_kv_set :: VarSet
    mentioned_kv_set = CandidatesQTvs -> VarSet
    candidateKindVars CandidatesQTvs
    candidates
                 specified :: [TyVar]
    specified        = [TyVar] -> [TyVar]
    scopedSort [TyVar]
    scoped_kvs
                                    -- NB: maintain the L-R order of scoped_kvs

                 final_tc_binders :: [TyConBinder]
    final_tc_binders =  ArgFlag -> [TyVar] -> [TyConBinder]
    mkNamedTyConBinders ArgFlag
    Inferred  [TyVar]
    inferred
                                  [TyConBinder] -> [TyConBinder] -> [TyConBinder]
    forall a. [a] -> [a] -> [a]
    ++ ArgFlag -> [TyVar] -> [TyConBinder]
    mkNamedTyConBinders ArgFlag
    Specified [TyVar]
    specified
                                  [TyConBinder] -> [TyConBinder] -> [TyConBinder]
    forall a. [a] -> [a] -> [a]
    ++ (TyVar -> TyConBinder) -> [TyVar] -> [TyConBinder]
    forall a b. (a -> b) -> [a] -> [b]
    map (VarSet -> TyVar -> TyConBinder
    mkRequiredTyConBinder VarSet
    mentioned_kv_set) [TyVar]
    tc_tvs

                 all_tv_prs :: [(Name, TyVar)]
    all_tv_prs =  [TyVar] -> [(Name, TyVar)]
    mkTyVarNamePairs ([TyVar]
    scoped_kvs [TyVar] -> [TyVar] -> [TyVar]
    forall a. [a] -> [a] -> [a]
    ++ [TyVar]
    tc_tvs)
                 tycon :: TyCon
    tycon = Name
    -> [TyConBinder]
    -> Type
    -> [(Name, TyVar)]
    -> Bool
    -> TyConFlavour
    -> TyCon
    mkTcTyCon Name
    name [TyConBinder]
    final_tc_binders Type
    res_kind [(Name, TyVar)]
    all_tv_prs
                                   Bool
    True -- it is generalised
                                   TyConFlavour
    flav

           ; SkolemInfo -> [TyVar] -> TcLevel -> WantedConstraints -> TcM ()
    reportUnsolvedEqualities SkolemInfo
    skol_info ([TyConBinder] -> [TyVar]
    forall tv argf. [VarBndr tv argf] -> [tv]
    binderVars [TyConBinder]
    final_tc_binders)
                                      TcLevel
    tclvl WantedConstraints
    wanted

             -- If the ordering from
             -- Note [Required, Specified, and Inferred for types] in GHC.Tc.TyCl
             -- doesn't work, we catch it here, before an error cascade
           ; TyCon -> TcM ()
    checkTyConTelescope TyCon
    tycon

           ; String -> SDoc -> TcM ()
    traceTc String
    "kcCheckDeclHeader_cusk " (SDoc -> TcM ()) -> SDoc -> TcM ()
    forall a b. (a -> b) -> a -> b
    $
             [SDoc] -> SDoc
    vcat [ String -> SDoc
    text String
    "name" SDoc -> SDoc -> SDoc
    <+> Name -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr Name
    name
                  , String -> SDoc
    text String
    "kv_ns" SDoc -> SDoc -> SDoc
    <+> HsQTvsRn -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr HsQTvsRn
    XHsQTvs GhcRn
    kv_ns
                  , String -> SDoc
    text String
    "hs_tvs" SDoc -> SDoc -> SDoc
    <+> [GenLocated SrcSpanAnnA (HsTyVarBndr () GhcRn)] -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr [GenLocated SrcSpanAnnA (HsTyVarBndr () GhcRn)]
    [LHsTyVarBndr () GhcRn]
    hs_tvs
                  , String -> SDoc
    text String
    "scoped_kvs" SDoc -> SDoc -> SDoc
    <+> [TyVar] -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr [TyVar]
    scoped_kvs
                  , String -> SDoc
    text String
    "tc_tvs" SDoc -> SDoc -> SDoc
    <+> [TyVar] -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr [TyVar]
    tc_tvs
                  , String -> SDoc
    text String
    "res_kind" SDoc -> SDoc -> SDoc
    <+> Type -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr Type
    res_kind
                  , String -> SDoc
    text String
    "candidates" SDoc -> SDoc -> SDoc
    <+> CandidatesQTvs -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr CandidatesQTvs
    candidates
                  , String -> SDoc
    text String
    "inferred" SDoc -> SDoc -> SDoc
    <+> [TyVar] -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr [TyVar]
    inferred
                  , String -> SDoc
    text String
    "specified" SDoc -> SDoc -> SDoc
    <+> [TyVar] -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr [TyVar]
    specified
                  , String -> SDoc
    text String
    "final_tc_binders" SDoc -> SDoc -> SDoc
    <+> [TyConBinder] -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr [TyConBinder]
    final_tc_binders
                  , String -> SDoc
    text String
    "mkTyConKind final_tc_bndrs res_kind"
                    SDoc -> SDoc -> SDoc
    <+> Type -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr ([TyConBinder] -> Type -> Type
    mkTyConKind [TyConBinder]
    final_tc_binders Type
    res_kind)
                  , String -> SDoc
    text String
    "all_tv_prs" SDoc -> SDoc -> SDoc
    <+> [(Name, TyVar)] -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr [(Name, TyVar)]
    all_tv_prs ]

           ; TyCon -> TcM TyCon
    forall (m :: * -> *) a. Monad m => a -> m a
    return TyCon
    tycon }
      where
        skol_info :: SkolemInfo
    skol_info = TyConFlavour -> Name -> SkolemInfo
    TyConSkol TyConFlavour
    flav Name
    name
        ctxt_kind :: ContextKind
    ctxt_kind | TyConFlavour -> Bool
    tcFlavourIsOpen TyConFlavour
    flav = Type -> ContextKind
    TheKind Type
    liftedTypeKind
                  | Bool
    otherwise            = ContextKind
    AnyKind

    -- | Kind-check a 'LHsQTyVars'. Used in 'inferInitialKind' (for tycon kinds and
    -- other kinds).
    --
    -- This function does not do telescope checking.
    kcInferDeclHeader
      :: Name              -- ^ of the thing being checked
      -> TyConFlavour      -- ^ What sort of 'TyCon' is being checked
      -> LHsQTyVars GhcRn
      -> TcM ContextKind   -- ^ The result kind
      -> TcM TcTyCon       -- ^ A suitably-kinded non-generalized TcTyCon
    kcInferDeclHeader :: Name
    -> TyConFlavour -> LHsQTyVars GhcRn -> TcM ContextKind -> TcM TyCon
    kcInferDeclHeader Name
    name TyConFlavour
    flav
                  (HsQTvs { hsq_ext :: forall pass. LHsQTyVars pass -> XHsQTvs pass
    hsq_ext = XHsQTvs GhcRn
    kv_ns
                          , hsq_explicit :: forall pass. LHsQTyVars pass -> [LHsTyVarBndr () pass]
    hsq_explicit = [LHsTyVarBndr () GhcRn]
    hs_tvs }) TcM ContextKind
    kc_res_ki
      -- No standalane kind signature and no CUSK.
      -- See note [Required, Specified, and Inferred for types] in GHC.Tc.TyCl
      = Name -> TyConFlavour -> TcM TyCon -> TcM TyCon
    forall a. Name -> TyConFlavour -> TcM a -> TcM a
    addTyConFlavCtxt Name
    name TyConFlavour
    flav (TcM TyCon -> TcM TyCon) -> TcM TyCon -> TcM TyCon
    forall a b. (a -> b) -> a -> b
    $
        do { ([TyVar]
    scoped_kvs, ([TyVar]
    tc_tvs, Type
    res_kind))
               -- Why bindImplicitTKBndrs_Q_Tv which uses newTyVarTyVar?
               -- See Note [Inferring kinds for type declarations] in GHC.Tc.TyCl
               <- HsQTvsRn -> TcM ([TyVar], Type) -> TcM ([TyVar], ([TyVar], Type))
    forall a. HsQTvsRn -> TcM a -> TcM ([TyVar], a)
    bindImplicitTKBndrs_Q_Tv HsQTvsRn
    XHsQTvs GhcRn
    kv_ns            (TcM ([TyVar], Type) -> TcM ([TyVar], ([TyVar], Type)))
    -> TcM ([TyVar], Type) -> TcM ([TyVar], ([TyVar], Type))
    forall a b. (a -> b) -> a -> b
    $
                  ContextKind
    -> [LHsTyVarBndr () GhcRn] -> TcM Type -> TcM ([TyVar], Type)
    forall a.
    ContextKind -> [LHsTyVarBndr () GhcRn] -> TcM a -> TcM ([TyVar], a)
    bindExplicitTKBndrs_Q_Tv ContextKind
    ctxt_kind [LHsTyVarBndr () GhcRn]
    hs_tvs (TcM Type -> TcM ([TyVar], Type))
    -> TcM Type -> TcM ([TyVar], Type)
    forall a b. (a -> b) -> a -> b
    $
                  ContextKind -> TcM Type
    newExpectedKind (ContextKind -> TcM Type) -> TcM ContextKind -> TcM Type
    forall (m :: * -> *) a b. Monad m => (a -> m b) -> m a -> m b
    =<< TcM ContextKind
    kc_res_ki
                  -- Why "_Tv" not "_Skol"? See third wrinkle in
                  -- Note [Inferring kinds for type declarations] in GHC.Tc.TyCl,

           ; let   -- NB: Don't add scoped_kvs to tyConTyVars, because they
                   -- might unify with kind vars in other types in a mutually
                   -- recursive group.
                   -- See Note [Inferring kinds for type declarations] in GHC.Tc.TyCl

                 tc_binders :: [TyConBinder]
    tc_binders = AnonArgFlag -> [TyVar] -> [TyConBinder]
    mkAnonTyConBinders AnonArgFlag
    VisArg [TyVar]
    tc_tvs
                   -- Also, note that tc_binders has the tyvars from only the
                   -- user-written tyvarbinders. See S1 in Note [How TcTyCons work]
                   -- in GHC.Tc.TyCl
                   --
                   -- mkAnonTyConBinder: see Note [No polymorphic recursion]

                 all_tv_prs :: [(Name, TyVar)]
    all_tv_prs = [TyVar] -> [(Name, TyVar)]
    mkTyVarNamePairs ([TyVar]
    scoped_kvs [TyVar] -> [TyVar] -> [TyVar]
    forall a. [a] -> [a] -> [a]
    ++ [TyVar]
    tc_tvs)
                   -- NB: bindExplicitTKBndrs_Q_Tv does not clone;
                   --     ditto Implicit
                   -- See Note [Cloning for type variable binders]

                 tycon :: TyCon
    tycon = Name
    -> [TyConBinder]
    -> Type
    -> [(Name, TyVar)]
    -> Bool
    -> TyConFlavour
    -> TyCon
    mkTcTyCon Name
    name [TyConBinder]
    tc_binders Type
    res_kind [(Name, TyVar)]
    all_tv_prs
                                   Bool
    False -- not yet generalised
                                   TyConFlavour
    flav

           ; String -> SDoc -> TcM ()
    traceTc String
    "kcInferDeclHeader: not-cusk" (SDoc -> TcM ()) -> SDoc -> TcM ()
    forall a b. (a -> b) -> a -> b
    $
             [SDoc] -> SDoc
    vcat [ Name -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr Name
    name, HsQTvsRn -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr HsQTvsRn
    XHsQTvs GhcRn
    kv_ns, [GenLocated SrcSpanAnnA (HsTyVarBndr () GhcRn)] -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr [GenLocated SrcSpanAnnA (HsTyVarBndr () GhcRn)]
    [LHsTyVarBndr () GhcRn]
    hs_tvs
                  , [TyVar] -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr [TyVar]
    scoped_kvs
                  , [TyVar] -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr [TyVar]
    tc_tvs, Type -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr ([TyConBinder] -> Type -> Type
    mkTyConKind [TyConBinder]
    tc_binders Type
    res_kind) ]
           ; TyCon -> TcM TyCon
    forall (m :: * -> *) a. Monad m => a -> m a
    return TyCon
    tycon }
      where
        ctxt_kind :: ContextKind
    ctxt_kind | TyConFlavour -> Bool
    tcFlavourIsOpen TyConFlavour
    flav = Type -> ContextKind
    TheKind Type
    liftedTypeKind
                  | Bool
    otherwise            = ContextKind
    AnyKind

    -- | Kind-check a declaration header against a standalone kind signature.
    -- See Note [Arity inference in kcCheckDeclHeader_sig]
    kcCheckDeclHeader_sig
      :: Kind              -- ^ Standalone kind signature, fully zonked! (zonkTcTypeToType)
      -> Name              -- ^ of the thing being checked
      -> TyConFlavour      -- ^ What sort of 'TyCon' is being checked
      -> LHsQTyVars GhcRn  -- ^ Binders in the header
      -> TcM ContextKind   -- ^ The result kind. AnyKind == no result signature
      -> TcM TcTyCon       -- ^ A suitably-kinded TcTyCon
    kcCheckDeclHeader_sig :: Type
    -> Name
    -> TyConFlavour
    -> LHsQTyVars GhcRn
    -> TcM ContextKind
    -> TcM TyCon
    kcCheckDeclHeader_sig Type
    kisig Name
    name TyConFlavour
    flav
              (HsQTvs { hsq_ext :: forall pass. LHsQTyVars pass -> XHsQTvs pass
    hsq_ext      = XHsQTvs GhcRn
    implicit_nms
                      , hsq_explicit :: forall pass. LHsQTyVars pass -> [LHsTyVarBndr () pass]
    hsq_explicit = [LHsTyVarBndr () GhcRn]
    explicit_nms }) TcM ContextKind
    kc_res_ki
      = Name -> TyConFlavour -> TcM TyCon -> TcM TyCon
    forall a. Name -> TyConFlavour -> TcM a -> TcM a
    addTyConFlavCtxt Name
    name TyConFlavour
    flav (TcM TyCon -> TcM TyCon) -> TcM TyCon -> TcM TyCon
    forall a b. (a -> b) -> a -> b
    $
        do {  -- Step 1: zip user-written binders with quantifiers from the kind signature.
              -- For example:
              --
              --   type F :: forall k -> k -> forall j. j -> Type
              --   data F i a b = ...
              --
              -- Results in the following 'zipped_binders':
              --
              --                   TyBinder      LHsTyVarBndr
              --    ---------------------------------------
              --    ZippedBinder   forall k ->   i
              --    ZippedBinder   k ->          a
              --    ZippedBinder   forall j.
              --    ZippedBinder   j ->          b
              --
              let ([ZippedBinder]
    zipped_binders, [LHsTyVarBndr () GhcRn]
    excess_bndrs, Type
    kisig') = Type
    -> [LHsTyVarBndr () GhcRn]
    -> ([ZippedBinder], [LHsTyVarBndr () GhcRn], Type)
    zipBinders Type
    kisig [LHsTyVarBndr () GhcRn]
    explicit_nms

              -- Report binders that don't have a corresponding quantifier.
              -- For example:
              --
              --   type T :: Type -> Type
              --   data T b1 b2 b3 = ...
              --
              -- Here, b1 is zipped with Type->, while b2 and b3 are excess binders.
              --
            ; Bool -> TcM () -> TcM ()
    forall (f :: * -> *). Applicative f => Bool -> f () -> f ()
    unless ([GenLocated SrcSpanAnnA (HsTyVarBndr () GhcRn)] -> Bool
    forall (t :: * -> *) a. Foldable t => t a -> Bool
    null [GenLocated SrcSpanAnnA (HsTyVarBndr () GhcRn)]
    [LHsTyVarBndr () GhcRn]
    excess_bndrs) (TcM () -> TcM ()) -> TcM () -> TcM ()
    forall a b. (a -> b) -> a -> b
    $ SDoc -> TcM ()
    forall a. SDoc -> TcM a
    failWithTc (Type -> [LHsTyVarBndr () GhcRn] -> SDoc
    tooManyBindersErr Type
    kisig' [LHsTyVarBndr () GhcRn]
    excess_bndrs)

              -- Convert each ZippedBinder to TyConBinder        for  tyConBinders
              --                       and to [(Name, TcTyVar)]  for  tcTyConScopedTyVars
            ; ([TyConBinder]
    vis_tcbs, [[(Name, TyVar)]] -> [(Name, TyVar)]
    forall (t :: * -> *) a. Foldable t => t [a] -> [a]
    concat -> [(Name, TyVar)]
    explicit_tv_prs) <- (ZippedBinder
     -> IOEnv (Env TcGblEnv TcLclEnv) (TyConBinder, [(Name, TyVar)]))
    -> [ZippedBinder]
    -> IOEnv (Env TcGblEnv TcLclEnv) ([TyConBinder], [[(Name, TyVar)]])
    forall (m :: * -> *) a b c.
    Applicative m =>
    (a -> m (b, c)) -> [a] -> m ([b], [c])
    mapAndUnzipM ZippedBinder
    -> IOEnv (Env TcGblEnv TcLclEnv) (TyConBinder, [(Name, TyVar)])
    zipped_to_tcb [ZippedBinder]
    zipped_binders

            ; (TcLevel
    tclvl, WantedConstraints
    wanted, ([TyVar]
    implicit_tvs, ([TyBinder]
    invis_binders, Type
    r_ki)))
                 <- String
    -> TcM ([TyVar], ([TyBinder], Type))
    -> TcM (TcLevel, WantedConstraints, ([TyVar], ([TyBinder], Type)))
    forall a. String -> TcM a -> TcM (TcLevel, WantedConstraints, a)
    pushLevelAndSolveEqualitiesX String
    "kcCheckDeclHeader_sig" (TcM ([TyVar], ([TyBinder], Type))
     -> TcM (TcLevel, WantedConstraints, ([TyVar], ([TyBinder], Type))))
    -> TcM ([TyVar], ([TyBinder], Type))
    -> TcM (TcLevel, WantedConstraints, ([TyVar], ([TyBinder], Type)))
    forall a b. (a -> b) -> a -> b
    $  -- #16687
                    HsQTvsRn
    -> TcM ([TyBinder], Type) -> TcM ([TyVar], ([TyBinder], Type))
    forall a. HsQTvsRn -> TcM a -> TcM ([TyVar], a)
    bindImplicitTKBndrs_Tv HsQTvsRn
    XHsQTvs GhcRn
    implicit_nms                  (TcM ([TyBinder], Type) -> TcM ([TyVar], ([TyBinder], Type)))
    -> TcM ([TyBinder], Type) -> TcM ([TyVar], ([TyBinder], Type))
    forall a b. (a -> b) -> a -> b
    $
                    [(Name, TyVar)] -> TcM ([TyBinder], Type) -> TcM ([TyBinder], Type)
    forall r. [(Name, TyVar)] -> TcM r -> TcM r
    tcExtendNameTyVarEnv [(Name, TyVar)]
    explicit_tv_prs                 (TcM ([TyBinder], Type) -> TcM ([TyBinder], Type))
    -> TcM ([TyBinder], Type) -> TcM ([TyBinder], Type)
    forall a b. (a -> b) -> a -> b
    $
                    do { -- Check that inline kind annotations on binders are valid.
                         -- For example:
                         --
                         --   type T :: Maybe k -> Type
                         --   data T (a :: Maybe j) = ...
                         --
                         -- Here we unify   Maybe k ~ Maybe j
                         (ZippedBinder -> TcM ()) -> [ZippedBinder] -> TcM ()
    forall (t :: * -> *) (m :: * -> *) a b.
    (Foldable t, Monad m) =>
    (a -> m b) -> t a -> m ()
    mapM_ ZippedBinder -> TcM ()
    check_zipped_binder [ZippedBinder]
    zipped_binders

                         -- Kind-check the result kind annotation, if present:
                         --
                         --    data T a b :: res_ki where
                         --               ^^^^^^^^^
                         -- We do it here because at this point the environment has been
                         -- extended with both 'implicit_tcv_prs' and 'explicit_tv_prs'.
                       ; ContextKind
    ctx_k    <- TcM ContextKind
    kc_res_ki
                       ; Maybe Type
    m_res_ki <- case ContextKind
    ctx_k of
                                      ContextKind
    AnyKind -> Maybe Type -> IOEnv (Env TcGblEnv TcLclEnv) (Maybe Type)
    forall (m :: * -> *) a. Monad m => a -> m a
    return Maybe Type
    forall a. Maybe a
    Nothing
                                      ContextKind
    _ -> Type -> Maybe Type
    forall a. a -> Maybe a
    Just (Type -> Maybe Type)
    -> TcM Type -> IOEnv (Env TcGblEnv TcLclEnv) (Maybe Type)
    forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
    <$> ContextKind -> TcM Type
    newExpectedKind ContextKind
    ctx_k

                         -- Step 2: split off invisible binders.
                         -- For example:
                         --
                         --   type F :: forall k1 k2. (k1, k2) -> Type
                         --   type family F
                         --
                         -- Does 'forall k1 k2' become a part of 'tyConBinders' or 'tyConResKind'?
                         -- See Note [Arity inference in kcCheckDeclHeader_sig]
                       ; let ([TyBinder]
    invis_binders, Type
    r_ki) = Type -> Maybe Type -> ([TyBinder], Type)
    split_invis Type
    kisig' Maybe Type
    m_res_ki

                         -- Check that the inline result kind annotation is valid.
                         -- For example:
                         --
                         --   type T :: Type -> Maybe k
                         --   type family T a :: Maybe j where
                         --
                         -- Here we unify   Maybe k ~ Maybe j
                       ; Maybe Type -> (Type -> TcM ()) -> TcM ()
    forall (m :: * -> *) a. Monad m => Maybe a -> (a -> m ()) -> m ()
    whenIsJust Maybe Type
    m_res_ki ((Type -> TcM ()) -> TcM ()) -> (Type -> TcM ()) -> TcM ()
    forall a b. (a -> b) -> a -> b
    $ \Type
    res_ki ->
                          TcM Coercion -> TcM ()
    forall a. TcM a -> TcM ()
    discardResult (TcM Coercion -> TcM ()) -> TcM Coercion -> TcM ()
    forall a b. (a -> b) -> a -> b
    $ -- See Note [discardResult in kcCheckDeclHeader_sig]
                          Maybe SDoc -> Type -> Type -> TcM Coercion
    unifyKind Maybe SDoc
    forall a. Maybe a
    Nothing Type
    r_ki Type
    res_ki

                       ; ([TyBinder], Type) -> TcM ([TyBinder], Type)
    forall (m :: * -> *) a. Monad m => a -> m a
    return ([TyBinder]
    invis_binders, Type
    r_ki) }

            -- Convert each invisible TyCoBinder to TyConBinder for tyConBinders.
            ; [TyConBinder]
    invis_tcbs <- (TyBinder -> IOEnv (Env TcGblEnv TcLclEnv) TyConBinder)
    -> [TyBinder] -> IOEnv (Env TcGblEnv TcLclEnv) [TyConBinder]
    forall (t :: * -> *) (m :: * -> *) a b.
    (Traversable t, Monad m) =>
    (a -> m b) -> t a -> m (t b)
    mapM TyBinder -> IOEnv (Env TcGblEnv TcLclEnv) TyConBinder
    invis_to_tcb [TyBinder]
    invis_binders

            -- Zonk the implicitly quantified variables.
            ; [TyVar]
    implicit_tvs <- (TyVar -> IOEnv (Env TcGblEnv TcLclEnv) TyVar)
    -> [TyVar] -> TcM [TyVar]
    forall (t :: * -> *) (m :: * -> *) a b.
    (Traversable t, Monad m) =>
    (a -> m b) -> t a -> m (t b)
    mapM HasDebugCallStack => TyVar -> IOEnv (Env TcGblEnv TcLclEnv) TyVar
    TyVar -> IOEnv (Env TcGblEnv TcLclEnv) TyVar
    zonkTcTyVarToTyVar [TyVar]
    implicit_tvs

            -- Build the final, generalized TcTyCon
            ; let tcbs :: [TyConBinder]
    tcbs            = [TyConBinder]
    vis_tcbs [TyConBinder] -> [TyConBinder] -> [TyConBinder]
    forall a. [a] -> [a] -> [a]
    ++ [TyConBinder]
    invis_tcbs
                  implicit_tv_prs :: [(Name, TyVar)]
    implicit_tv_prs = HsQTvsRn
    XHsQTvs GhcRn
    implicit_nms HsQTvsRn -> [TyVar] -> [(Name, TyVar)]
    forall a b. [a] -> [b] -> [(a, b)]
    `zip` [TyVar]
    implicit_tvs
                  all_tv_prs :: [(Name, TyVar)]
    all_tv_prs      = [(Name, TyVar)]
    implicit_tv_prs [(Name, TyVar)] -> [(Name, TyVar)] -> [(Name, TyVar)]
    forall a. [a] -> [a] -> [a]
    ++ [(Name, TyVar)]
    explicit_tv_prs
                  tc :: TyCon
    tc              = Name
    -> [TyConBinder]
    -> Type
    -> [(Name, TyVar)]
    -> Bool
    -> TyConFlavour
    -> TyCon
    mkTcTyCon Name
    name [TyConBinder]
    tcbs Type
    r_ki [(Name, TyVar)]
    all_tv_prs Bool
    True TyConFlavour
    flav
                  skol_info :: SkolemInfo
    skol_info       = TyConFlavour -> Name -> SkolemInfo
    TyConSkol TyConFlavour
    flav Name
    name

            -- Check that there are no unsolved equalities
            ; SkolemInfo -> [TyVar] -> TcLevel -> WantedConstraints -> TcM ()
    reportUnsolvedEqualities SkolemInfo
    skol_info ([TyConBinder] -> [TyVar]
    forall tv argf. [VarBndr tv argf] -> [tv]
    binderVars [TyConBinder]
    tcbs) TcLevel
    tclvl WantedConstraints
    wanted

            ; String -> SDoc -> TcM ()
    traceTc String
    "kcCheckDeclHeader_sig done:" (SDoc -> TcM ()) -> SDoc -> TcM ()
    forall a b. (a -> b) -> a -> b
    $ [SDoc] -> SDoc
    vcat
              [ String -> SDoc
    text String
    "tyConName = " SDoc -> SDoc -> SDoc
    <+> Name -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr (TyCon -> Name
    tyConName TyCon
    tc)
              , String -> SDoc
    text String
    "kisig =" SDoc -> SDoc -> SDoc
    <+> Type -> SDoc
    debugPprType Type
    kisig
              , String -> SDoc
    text String
    "tyConKind =" SDoc -> SDoc -> SDoc
    <+> Type -> SDoc
    debugPprType (TyCon -> Type
    tyConKind TyCon
    tc)
              , String -> SDoc
    text String
    "tyConBinders = " SDoc -> SDoc -> SDoc
    <+> [TyConBinder] -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr (TyCon -> [TyConBinder]
    tyConBinders TyCon
    tc)
              , String -> SDoc
    text String
    "tcTyConScopedTyVars" SDoc -> SDoc -> SDoc
    <+> [(Name, TyVar)] -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr (TyCon -> [(Name, TyVar)]
    tcTyConScopedTyVars TyCon
    tc)
              , String -> SDoc
    text String
    "tyConResKind" SDoc -> SDoc -> SDoc
    <+> Type -> SDoc
    debugPprType (TyCon -> Type
    tyConResKind TyCon
    tc)
              ]
            ; TyCon -> TcM TyCon
    forall (m :: * -> *) a. Monad m => a -> m a
    return TyCon
    tc }
      where
        -- Consider this declaration:
        --
        --    type T :: forall a. forall b -> (a~b) => Proxy a -> Type
        --    data T x p = MkT
        --
        -- Here, we have every possible variant of ZippedBinder:
        --
        --                   TyBinder           LHsTyVarBndr
        --    ----------------------------------------------
        --    ZippedBinder   forall {k}.
        --    ZippedBinder   forall (a::k).
        --    ZippedBinder   forall (b::k) ->   x
        --    ZippedBinder   (a~b) =>
        --    ZippedBinder   Proxy a ->         p
        --
        -- Given a ZippedBinder zipped_to_tcb produces:
        --
        --  * TyConBinder      for  tyConBinders
        --  * (Name, TcTyVar)  for  tcTyConScopedTyVars, if there's a user-written LHsTyVarBndr
        --
        zipped_to_tcb :: ZippedBinder -> TcM (TyConBinder, [(Name, TcTyVar)])
        zipped_to_tcb :: ZippedBinder
    -> IOEnv (Env TcGblEnv TcLclEnv) (TyConBinder, [(Name, TyVar)])
    zipped_to_tcb ZippedBinder
    zb = case ZippedBinder
    zb of

          -- Inferred variable, no user-written binder.
          -- Example:   forall {k}.
          ZippedBinder (Named (Bndr TyVar
    v ArgFlag
    Specified)) Maybe (LHsTyVarBndr () GhcRn)
    Nothing ->
            (TyConBinder, [(Name, TyVar)])
    -> IOEnv (Env TcGblEnv TcLclEnv) (TyConBinder, [(Name, TyVar)])
    forall (m :: * -> *) a. Monad m => a -> m a
    return (ArgFlag -> TyVar -> TyConBinder
    mkNamedTyConBinder ArgFlag
    Specified TyVar
    v, [])

          -- Specified variable, no user-written binder.
          -- Example:   forall (a::k).
          ZippedBinder (Named (Bndr TyVar
    v ArgFlag
    Inferred)) Maybe (LHsTyVarBndr () GhcRn)
    Nothing ->
            (TyConBinder, [(Name, TyVar)])
    -> IOEnv (Env TcGblEnv TcLclEnv) (TyConBinder, [(Name, TyVar)])
    forall (m :: * -> *) a. Monad m => a -> m a
    return (ArgFlag -> TyVar -> TyConBinder
    mkNamedTyConBinder ArgFlag
    Inferred TyVar
    v, [])

          -- Constraint, no user-written binder.
          -- Example:   (a~b) =>
          ZippedBinder (Anon AnonArgFlag
    InvisArg Scaled Type
    bndr_ki) Maybe (LHsTyVarBndr () GhcRn)
    Nothing -> do
            Name
    name <- OccName -> TcM Name
    forall gbl lcl. OccName -> TcRnIf gbl lcl Name
    newSysName (FastString -> OccName
    mkTyVarOccFS (String -> FastString
    fsLit String
    "ev"))
            let tv :: TyVar
    tv = Name -> Type -> TyVar
    mkTyVar Name
    name (Scaled Type -> Type
    forall a. Scaled a -> a
    scaledThing Scaled Type
    bndr_ki)
            (TyConBinder, [(Name, TyVar)])
    -> IOEnv (Env TcGblEnv TcLclEnv) (TyConBinder, [(Name, TyVar)])
    forall (m :: * -> *) a. Monad m => a -> m a
    return (AnonArgFlag -> TyVar -> TyConBinder
    mkAnonTyConBinder AnonArgFlag
    InvisArg TyVar
    tv, [])

          -- Non-dependent visible argument with a user-written binder.
          -- Example:   Proxy a ->
          ZippedBinder (Anon AnonArgFlag
    VisArg Scaled Type
    bndr_ki) (Just LHsTyVarBndr () GhcRn
    b) ->
            (TyConBinder, [(Name, TyVar)])
    -> IOEnv (Env TcGblEnv TcLclEnv) (TyConBinder, [(Name, TyVar)])
    forall (m :: * -> *) a. Monad m => a -> m a
    return ((TyConBinder, [(Name, TyVar)])
     -> IOEnv (Env TcGblEnv TcLclEnv) (TyConBinder, [(Name, TyVar)]))
    -> (TyConBinder, [(Name, TyVar)])
    -> IOEnv (Env TcGblEnv TcLclEnv) (TyConBinder, [(Name, TyVar)])
    forall a b. (a -> b) -> a -> b
    $
              let v_name :: Name
    v_name = GenLocated SrcSpanAnnA (HsTyVarBndr () GhcRn) -> Name
    forall a. NamedThing a => a -> Name
    getName GenLocated SrcSpanAnnA (HsTyVarBndr () GhcRn)
    LHsTyVarBndr () GhcRn
    b
                  tv :: TyVar
    tv = Name -> Type -> TyVar
    mkTyVar Name
    v_name (Scaled Type -> Type
    forall a. Scaled a -> a
    scaledThing Scaled Type
    bndr_ki)
                  tcb :: TyConBinder
    tcb = AnonArgFlag -> TyVar -> TyConBinder
    mkAnonTyConBinder AnonArgFlag
    VisArg TyVar
    tv
              in (TyConBinder
    tcb, [(Name
    v_name, TyVar
    tv)])

          -- Dependent visible argument with a user-written binder.
          -- Example:   forall (b::k) ->
          ZippedBinder (Named (Bndr TyVar
    v ArgFlag
    Required)) (Just LHsTyVarBndr () GhcRn
    b) ->
            (TyConBinder, [(Name, TyVar)])
    -> IOEnv (Env TcGblEnv TcLclEnv) (TyConBinder, [(Name, TyVar)])
    forall (m :: * -> *) a. Monad m => a -> m a
    return ((TyConBinder, [(Name, TyVar)])
     -> IOEnv (Env TcGblEnv TcLclEnv) (TyConBinder, [(Name, TyVar)]))
    -> (TyConBinder, [(Name, TyVar)])
    -> IOEnv (Env TcGblEnv TcLclEnv) (TyConBinder, [(Name, TyVar)])
    forall a b. (a -> b) -> a -> b
    $
              let v_name :: Name
    v_name = GenLocated SrcSpanAnnA (HsTyVarBndr () GhcRn) -> Name
    forall a. NamedThing a => a -> Name
    getName GenLocated SrcSpanAnnA (HsTyVarBndr () GhcRn)
    LHsTyVarBndr () GhcRn
    b
                  tcb :: TyConBinder
    tcb = ArgFlag -> TyVar -> TyConBinder
    mkNamedTyConBinder ArgFlag
    Required TyVar
    v
              in (TyConBinder
    tcb, [(Name
    v_name, TyVar
    v)])

          -- 'zipBinders' does not produce any other variants of ZippedBinder.
          ZippedBinder
    _ -> String
    -> IOEnv (Env TcGblEnv TcLclEnv) (TyConBinder, [(Name, TyVar)])
    forall a. String -> a
    panic String
    "goVis: invalid ZippedBinder"

        -- Given an invisible binder that comes from 'split_invis',
        -- convert it to TyConBinder.
        invis_to_tcb :: TyCoBinder -> TcM TyConBinder
        invis_to_tcb :: TyBinder -> IOEnv (Env TcGblEnv TcLclEnv) TyConBinder
    invis_to_tcb TyBinder
    tb = do
          (TyConBinder
    tcb, [(Name, TyVar)]
    stv) <- ZippedBinder
    -> IOEnv (Env TcGblEnv TcLclEnv) (TyConBinder, [(Name, TyVar)])
    zipped_to_tcb (TyBinder -> Maybe (LHsTyVarBndr () GhcRn) -> ZippedBinder
    ZippedBinder TyBinder
    tb Maybe (LHsTyVarBndr () GhcRn)
    forall a. Maybe a
    Nothing)
          MASSERT(null stv)
          TyConBinder -> IOEnv (Env TcGblEnv TcLclEnv) TyConBinder
    forall (m :: * -> *) a. Monad m => a -> m a
    return TyConBinder
    tcb

        -- Check that the inline kind annotation on a binder is valid
        -- by unifying it with the kind of the quantifier.
        check_zipped_binder :: ZippedBinder -> TcM ()
        check_zipped_binder :: ZippedBinder -> TcM ()
    check_zipped_binder (ZippedBinder TyBinder
    _ Maybe (LHsTyVarBndr () GhcRn)
    Nothing) = () -> TcM ()
    forall (m :: * -> *) a. Monad m => a -> m a
    return ()
        check_zipped_binder (ZippedBinder TyBinder
    tb (Just LHsTyVarBndr () GhcRn
    b)) =
          case GenLocated SrcSpanAnnA (HsTyVarBndr () GhcRn)
    -> HsTyVarBndr () GhcRn
    forall l e. GenLocated l e -> e
    unLoc GenLocated SrcSpanAnnA (HsTyVarBndr () GhcRn)
    LHsTyVarBndr () GhcRn
    b of
            UserTyVar XUserTyVar GhcRn
    _ ()
    _ LIdP GhcRn
    _ -> () -> TcM ()
    forall (m :: * -> *) a. Monad m => a -> m a
    return ()
            KindedTyVar XKindedTyVar GhcRn
    _ ()
    _ LIdP GhcRn
    v LHsType GhcRn
    v_hs_ki -> do
              Type
    v_ki <- UserTypeCtxt -> LHsType GhcRn -> TcM Type
    tcLHsKindSig (Name -> UserTypeCtxt
    TyVarBndrKindCtxt (GenLocated SrcSpanAnnN Name -> Name
    forall l e. GenLocated l e -> e
    unLoc GenLocated SrcSpanAnnN Name
    LIdP GhcRn
    v)) LHsType GhcRn
    v_hs_ki
              TcM Coercion -> TcM ()
    forall a. TcM a -> TcM ()
    discardResult (TcM Coercion -> TcM ()) -> TcM Coercion -> TcM ()
    forall a b. (a -> b) -> a -> b
    $ -- See Note [discardResult in kcCheckDeclHeader_sig]
                Maybe SDoc -> Type -> Type -> TcM Coercion
    unifyKind (SDoc -> Maybe SDoc
    forall a. a -> Maybe a
    Just (GenLocated SrcSpanAnnN Name -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr GenLocated SrcSpanAnnN Name
    LIdP GhcRn
    v))
                          (TyBinder -> Type
    tyBinderType TyBinder
    tb)
                          Type
    v_ki

        -- Split the invisible binders that should become a part of 'tyConBinders'
        -- rather than 'tyConResKind'.
        -- See Note [Arity inference in kcCheckDeclHeader_sig]
        split_invis :: Kind -> Maybe Kind -> ([TyCoBinder], Kind)
        split_invis :: Type -> Maybe Type -> ([TyBinder], Type)
    split_invis Type
    sig_ki Maybe Type
    Nothing =
          -- instantiate all invisible binders
          Type -> ([TyBinder], Type)
    splitInvisPiTys Type
    sig_ki
        split_invis Type
    sig_ki (Just Type
    res_ki) =
          -- subtraction a la checkExpectedKind
          let n_res_invis_bndrs :: Arity
    n_res_invis_bndrs = Type -> Arity
    invisibleTyBndrCount Type
    res_ki
              n_sig_invis_bndrs :: Arity
    n_sig_invis_bndrs = Type -> Arity
    invisibleTyBndrCount Type
    sig_ki
              n_inst :: Arity
    n_inst = Arity
    n_sig_invis_bndrs Arity -> Arity -> Arity
    forall a. Num a => a -> a -> a
    - Arity
    n_res_invis_bndrs
          in Arity -> Type -> ([TyBinder], Type)
    splitInvisPiTysN Arity
    n_inst Type
    sig_ki

    -- A quantifier from a kind signature zipped with a user-written binder for it.
    data ZippedBinder = ZippedBinder TyBinder (Maybe (LHsTyVarBndr () GhcRn))

    -- See Note [Arity inference in kcCheckDeclHeader_sig]
    zipBinders
      :: Kind                      -- Kind signature
      -> [LHsTyVarBndr () GhcRn]   -- User-written binders
      -> ( [ZippedBinder]          -- Zipped binders
         , [LHsTyVarBndr () GhcRn] -- Leftover user-written binders
         , Kind )                  -- Remainder of the kind signature
    zipBinders :: Type
    -> [LHsTyVarBndr () GhcRn]
    -> ([ZippedBinder], [LHsTyVarBndr () GhcRn], Type)
    zipBinders = [ZippedBinder]
    -> TCvSubst
    -> Type
    -> [GenLocated SrcSpanAnnA (HsTyVarBndr () GhcRn)]
    -> ([ZippedBinder],
        [GenLocated SrcSpanAnnA (HsTyVarBndr () GhcRn)], Type)
    zip_binders [] TCvSubst
    emptyTCvSubst
      where
        -- subst: we substitute as we go, to ensure that the resulting
        -- binders in the [ZippedBndr] all have distinct uniques.
        -- If not, the TyCon may get multiple binders with the same unique,
        -- which results in chaos (see #19092,3,4)
        -- (The incoming kind might be forall k. k -> forall k. k -> Type
        --  where those two k's have the same unique. Without the substitution
        --  we'd get a repeated 'k'.)
        zip_binders :: [ZippedBinder]
    -> TCvSubst
    -> Type
    -> [GenLocated SrcSpanAnnA (HsTyVarBndr () GhcRn)]
    -> ([ZippedBinder],
        [GenLocated SrcSpanAnnA (HsTyVarBndr () GhcRn)], Type)
    zip_binders [ZippedBinder]
    acc TCvSubst
    subst Type
    ki [GenLocated SrcSpanAnnA (HsTyVarBndr () GhcRn)]
    bs
          | (GenLocated SrcSpanAnnA (HsTyVarBndr () GhcRn)
    b:[GenLocated SrcSpanAnnA (HsTyVarBndr () GhcRn)]
    bs') <- [GenLocated SrcSpanAnnA (HsTyVarBndr () GhcRn)]
    bs  -- Stop as soon as 'bs' becomes empty
          , Just (TyBinder
    tb,Type
    ki') <- Type -> Maybe (TyBinder, Type)
    tcSplitPiTy_maybe Type
    ki
          , let (TCvSubst
    subst', TyBinder
    tb') = TCvSubst -> TyBinder -> (TCvSubst, TyBinder)
    substTyCoBndr TCvSubst
    subst TyBinder
    tb
          = if TyBinder -> Bool
    isInvisibleBinder TyBinder
    tb
            then [ZippedBinder]
    -> TCvSubst
    -> Type
    -> [GenLocated SrcSpanAnnA (HsTyVarBndr () GhcRn)]
    -> ([ZippedBinder],
        [GenLocated SrcSpanAnnA (HsTyVarBndr () GhcRn)], Type)
    zip_binders (TyBinder -> Maybe (LHsTyVarBndr () GhcRn) -> ZippedBinder
    ZippedBinder TyBinder
    tb' Maybe (LHsTyVarBndr () GhcRn)
    forall a. Maybe a
    Nothing  ZippedBinder -> [ZippedBinder] -> [ZippedBinder]
    forall a. a -> [a] -> [a]
    : [ZippedBinder]
    acc) TCvSubst
    subst' Type
    ki' [GenLocated SrcSpanAnnA (HsTyVarBndr () GhcRn)]
    bs
            else [ZippedBinder]
    -> TCvSubst
    -> Type
    -> [GenLocated SrcSpanAnnA (HsTyVarBndr () GhcRn)]
    -> ([ZippedBinder],
        [GenLocated SrcSpanAnnA (HsTyVarBndr () GhcRn)], Type)
    zip_binders (TyBinder -> Maybe (LHsTyVarBndr () GhcRn) -> ZippedBinder
    ZippedBinder TyBinder
    tb' (GenLocated SrcSpanAnnA (HsTyVarBndr () GhcRn)
    -> Maybe (GenLocated SrcSpanAnnA (HsTyVarBndr () GhcRn))
    forall a. a -> Maybe a
    Just GenLocated SrcSpanAnnA (HsTyVarBndr () GhcRn)
    b) ZippedBinder -> [ZippedBinder] -> [ZippedBinder]
    forall a. a -> [a] -> [a]
    : [ZippedBinder]
    acc) TCvSubst
    subst' Type
    ki' [GenLocated SrcSpanAnnA (HsTyVarBndr () GhcRn)]
    bs'

          | Bool
    otherwise
          = ([ZippedBinder] -> [ZippedBinder]
    forall a. [a] -> [a]
    reverse [ZippedBinder]
    acc, [GenLocated SrcSpanAnnA (HsTyVarBndr () GhcRn)]
    bs, HasCallStack => TCvSubst -> Type -> Type
    TCvSubst -> Type -> Type
    substTy TCvSubst
    subst Type
    ki)

    tooManyBindersErr :: Kind -> [LHsTyVarBndr () GhcRn] -> SDoc
    tooManyBindersErr :: Type -> [LHsTyVarBndr () GhcRn] -> SDoc
    tooManyBindersErr Type
    ki [LHsTyVarBndr () GhcRn]
    bndrs =
       SDoc -> Arity -> SDoc -> SDoc
    hang (String -> SDoc
    text String
    "Not a function kind:")
          Arity
    4 (Type -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr Type
    ki) SDoc -> SDoc -> SDoc
    $$
       SDoc -> Arity -> SDoc -> SDoc
    hang (String -> SDoc
    text String
    "but extra binders found:")
          Arity
    4 ([SDoc] -> SDoc
    fsep ((GenLocated SrcSpanAnnA (HsTyVarBndr () GhcRn) -> SDoc)
    -> [GenLocated SrcSpanAnnA (HsTyVarBndr () GhcRn)] -> [SDoc]
    forall a b. (a -> b) -> [a] -> [b]
    map GenLocated SrcSpanAnnA (HsTyVarBndr () GhcRn) -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr [GenLocated SrcSpanAnnA (HsTyVarBndr () GhcRn)]
    [LHsTyVarBndr () GhcRn]
    bndrs))

    {- Note [Arity inference in kcCheckDeclHeader_sig]
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    Given a kind signature 'kisig' and a declaration header, kcCheckDeclHeader_sig
    verifies that the declaration conforms to the signature. The end result is a
    TcTyCon 'tc' such that:

      tyConKind tc == kisig

    This TcTyCon would be rather easy to produce if we didn't have to worry about
    arity. Consider these declarations:

      type family S1 :: forall k. k -> Type
      type family S2 (a :: k) :: Type

    Both S1 and S2 can be given the same standalone kind signature:

      type S2 :: forall k. k -> Type

    And, indeed, tyConKind S1 == tyConKind S2. However, tyConKind is built from
    tyConBinders and tyConResKind, such that

      tyConKind tc == mkTyConKind (tyConBinders tc) (tyConResKind tc)

    For S1 and S2, tyConBinders and tyConResKind are different:

      tyConBinders S1  ==  []
      tyConResKind S1  ==  forall k. k -> Type
      tyConKind    S1  ==  forall k. k -> Type

      tyConBinders S2  ==  [spec k, anon-vis (a :: k)]
      tyConResKind S2  ==  Type
      tyConKind    S1  ==  forall k. k -> Type

    This difference determines the arity:

      tyConArity tc == length (tyConBinders tc)

    That is, the arity of S1 is 0, while the arity of S2 is 2.

    'kcCheckDeclHeader_sig' needs to infer the desired arity to split the standalone
    kind signature into binders and the result kind. It does so in two rounds:

    1. zip user-written binders (vis_tcbs)
    2. split off invisible binders (invis_tcbs)

    Consider the following declarations:

        type F :: Type -> forall j. j -> forall k1 k2. (k1, k2) -> Type
        type family F a b

        type G :: Type -> forall j. j -> forall k1 k2. (k1, k2) -> Type
        type family G a b :: forall r2. (r1, r2) -> Type

    In step 1 (zip user-written binders), we zip the quantifiers in the signature
    with the binders in the header using 'zipBinders'. In both F and G, this results in
    the following zipped binders:

                       TyBinder     LHsTyVarBndr
        ---------------------------------------
        ZippedBinder   Type ->      a
        ZippedBinder   forall j.
        ZippedBinder   j ->         b

    At this point, we have accumulated three zipped binders which correspond to a
    prefix of the standalone kind signature:

      Type -> forall j. j -> ...

    In step 2 (split off invisible binders), we have to decide how much remaining
    invisible binders of the standalone kind signature to split off:

        forall k1 k2. (k1, k2) -> Type
        ^^^^^^^^^^^^^
        split off or not?

    This decision is made in 'split_invis':

    * If a user-written result kind signature is not provided, as in F,
      then split off all invisible binders. This is why we need special treatment
      for AnyKind.
    * If a user-written result kind signature is provided, as in G,
      then do as checkExpectedKind does and split off (n_sig - n_res) binders.
      That is, split off such an amount of binders that the remainder of the
      standalone kind signature and the user-written result kind signature have the
      same amount of invisible quantifiers.

    For F, split_invis splits away all invisible binders, and we have 2:

        forall k1 k2. (k1, k2) -> Type
        ^^^^^^^^^^^^^
        split away both binders

    The resulting arity of F is 3+2=5.  (length vis_tcbs = 3,
                                         length invis_tcbs = 2,
                                         length tcbs = 5)

    For G, split_invis decides to split off 1 invisible binder, so that we have the
    same amount of invisible quantifiers left:

        res_ki  =  forall    r2. (r1, r2) -> Type
        kisig   =  forall k1 k2. (k1, k2) -> Type
                         ^^^
                         split off this one.

    The resulting arity of G is 3+1=4. (length vis_tcbs = 3,
                                        length invis_tcbs = 1,
                                        length tcbs = 4)

    -}

    {- Note [discardResult in kcCheckDeclHeader_sig]
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    We use 'unifyKind' to check inline kind annotations in declaration headers
    against the signature.

      type T :: [i] -> Maybe j -> Type
      data T (a :: [k1]) (b :: Maybe k2) :: Type where ...

    Here, we will unify:

           [k1] ~ [i]
      Maybe k2  ~ Maybe j
          Type  ~ Type

    The end result is that we fill in unification variables k1, k2:

        k1  :=  i
        k2  :=  j

    We also validate that the user isn't confused:

      type T :: Type -> Type
      data T (a :: Bool) = ...

    This will report that (Type ~ Bool) failed to unify.

    Now, consider the following example:

      type family Id a where Id x = x
      type T :: Bool -> Type
      type T (a :: Id Bool) = ...

    We will unify (Bool ~ Id Bool), and this will produce a non-reflexive coercion.
    However, we are free to discard it, as the kind of 'T' is determined by the
    signature, not by the inline kind annotation:

          we have   T ::    Bool -> Type
      rather than   T :: Id Bool -> Type

    This (Id Bool) will not show up anywhere after we're done validating it, so we
    have no use for the produced coercion.
    -}

    {- Note [No polymorphic recursion]
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    Should this kind-check?
      data T ka (a::ka) b  = MkT (T Type           Int   Bool)
                                 (T (Type -> Type) Maybe Bool)

    Notice that T is used at two different kinds in its RHS.  No!
    This should not kind-check.  Polymorphic recursion is known to
    be a tough nut.

    Previously, we laboriously (with help from the renamer)
    tried to give T the polymorphic kind
       T :: forall ka -> ka -> kappa -> Type
    where kappa is a unification variable, even in the inferInitialKinds
    phase (which is what kcInferDeclHeader is all about).  But
    that is dangerously fragile (see the ticket).

    Solution: make kcInferDeclHeader give T a straightforward
    monomorphic kind, with no quantification whatsoever. That's why
    we use mkAnonTyConBinder for all arguments when figuring out
    tc_binders.

    But notice that (#16322 comment:3)

    * The algorithm successfully kind-checks this declaration:
        data T2 ka (a::ka) = MkT2 (T2 Type a)

      Starting with (inferInitialKinds)
        T2 :: (kappa1 :: kappa2 :: *) -> (kappa3 :: kappa4 :: *) -> *
      we get
        kappa4 := kappa1   -- from the (a:ka) kind signature
        kappa1 := Type     -- From application T2 Type

      These constraints are soluble so generaliseTcTyCon gives
        T2 :: forall (k::Type) -> k -> *

      But now the /typechecking/ (aka desugaring, tcTyClDecl) phase
      fails, because the call (T2 Type a) in the RHS is ill-kinded.

      We'd really prefer all errors to show up in the kind checking
      phase.

    * This algorithm still accepts (in all phases)
         data T3 ka (a::ka) = forall b. MkT3 (T3 Type b)
      although T3 is really polymorphic-recursive too.
      Perhaps we should somehow reject that.

    Note [Kind variable ordering for associated types]
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    What should be the kind of `T` in the following example? (#15591)

      class C (a :: Type) where
        type T (x :: f a)

    As per Note [Ordering of implicit variables] in GHC.Rename.HsType, we want to quantify
    the kind variables in left-to-right order of first occurrence in order to
    support visible kind application. But we cannot perform this analysis on just
    T alone, since its variable `a` actually occurs /before/ `f` if you consider
    the fact that `a` was previously bound by the parent class `C`. That is to say,
    the kind of `T` should end up being:

      T :: forall a f. f a -> Type

    (It wouldn't necessarily be /wrong/ if the kind ended up being, say,
    forall f a. f a -> Type, but that would not be as predictable for users of
    visible kind application.)

    In contrast, if `T` were redefined to be a top-level type family, like `T2`
    below:

      type family T2 (x :: f (a :: Type))

    Then `a` first appears /after/ `f`, so the kind of `T2` should be:

      T2 :: forall f a. f a -> Type

    In order to make this distinction, we need to know (in kcCheckDeclHeader) which
    type variables have been bound by the parent class (if there is one). With
    the class-bound variables in hand, we can ensure that we always quantify
    these first.
    -}

    {- *********************************************************************
    *                                                                      *
                 Expected kinds
    *                                                                      *
    ********************************************************************* -}

    -- | Describes the kind expected in a certain context.
    data ContextKind = TheKind Kind   -- ^ a specific kind
                     | AnyKind        -- ^ any kind will do
                     | OpenKind       -- ^ something of the form @TYPE _@

    -----------------------
    newExpectedKind :: ContextKind -> TcM Kind
    newExpectedKind :: ContextKind -> TcM Type
    newExpectedKind (TheKind Type
    k)   = Type -> TcM Type
    forall (m :: * -> *) a. Monad m => a -> m a
    return Type
    k
    newExpectedKind ContextKind
    AnyKind       = TcM Type
    newMetaKindVar
    newExpectedKind ContextKind
    OpenKind      = TcM Type
    newOpenTypeKind

    -----------------------
    expectedKindInCtxt :: UserTypeCtxt -> ContextKind
    -- Depending on the context, we might accept any kind (for instance, in a TH
    -- splice), or only certain kinds (like in type signatures).
    expectedKindInCtxt :: UserTypeCtxt -> ContextKind
    expectedKindInCtxt (TySynCtxt Name
    _)   = ContextKind
    AnyKind
    expectedKindInCtxt (GhciCtxt {})   = ContextKind
    AnyKind
    -- The types in a 'default' decl can have varying kinds
    -- See Note [Extended defaults]" in GHC.Tc.Utils.Env
    expectedKindInCtxt UserTypeCtxt
    DefaultDeclCtxt     = ContextKind
    AnyKind
    expectedKindInCtxt UserTypeCtxt
    DerivClauseCtxt     = ContextKind
    AnyKind
    expectedKindInCtxt UserTypeCtxt
    TypeAppCtxt         = ContextKind
    AnyKind
    expectedKindInCtxt (ForSigCtxt Name
    _)      = Type -> ContextKind
    TheKind Type
    liftedTypeKind
    expectedKindInCtxt (InstDeclCtxt {})   = Type -> ContextKind
    TheKind Type
    constraintKind
    expectedKindInCtxt UserTypeCtxt
    SpecInstCtxt        = Type -> ContextKind
    TheKind Type
    constraintKind
    expectedKindInCtxt UserTypeCtxt
    _                   = ContextKind
    OpenKind

    {- *********************************************************************
    *                                                                      *
                 Bringing type variables into scope
    *                                                                      *
    ********************************************************************* -}

    --------------------------------------
    --    HsForAllTelescope
    --------------------------------------

    tcTKTelescope :: TcTyMode
                  -> HsForAllTelescope GhcRn
                  -> TcM a
                  -> TcM ([TcTyVarBinder], a)
    tcTKTelescope :: forall a.
    TcTyMode
    -> HsForAllTelescope GhcRn -> TcM a -> TcM ([TcTyVarBinder], a)
    tcTKTelescope TcTyMode
    mode HsForAllTelescope GhcRn
    tele TcM a
    thing_inside = case HsForAllTelescope GhcRn
    tele of
      HsForAllVis { hsf_vis_bndrs :: forall pass. HsForAllTelescope pass -> [LHsTyVarBndr () pass]
    hsf_vis_bndrs = [LHsTyVarBndr () GhcRn]
    bndrs }
        -> do { ([VarBndr TyVar ()]
    req_tv_bndrs, a
    thing) <- SkolemMode
    -> [LHsTyVarBndr () GhcRn] -> TcM a -> TcM ([VarBndr TyVar ()], a)
    forall flag a.
    OutputableBndrFlag flag 'Renamed =>
    SkolemMode
    -> [LHsTyVarBndr flag GhcRn]
    -> TcM a
    -> TcM ([VarBndr TyVar flag], a)
    tcExplicitTKBndrsX SkolemMode
    skol_mode [LHsTyVarBndr () GhcRn]
    bndrs TcM a
    thing_inside
                -- req_tv_bndrs :: [VarBndr TyVar ()],
                -- but we want [VarBndr TyVar ArgFlag]
              ; ([TcTyVarBinder], a) -> TcM ([TcTyVarBinder], a)
    forall (m :: * -> *) a. Monad m => a -> m a
    return ([VarBndr TyVar ()] -> [TcTyVarBinder]
    forall a. [VarBndr a ()] -> [VarBndr a ArgFlag]
    tyVarReqToBinders [VarBndr TyVar ()]
    req_tv_bndrs, a
    thing) }

      HsForAllInvis { hsf_invis_bndrs :: forall pass.
    HsForAllTelescope pass -> [LHsTyVarBndr Specificity pass]
    hsf_invis_bndrs = [LHsTyVarBndr Specificity GhcRn]
    bndrs }
        -> do { ([InvisTVBinder]
    inv_tv_bndrs, a
    thing) <- SkolemMode
    -> [LHsTyVarBndr Specificity GhcRn]
    -> TcM a
    -> TcM ([InvisTVBinder], a)
    forall flag a.
    OutputableBndrFlag flag 'Renamed =>
    SkolemMode
    -> [LHsTyVarBndr flag GhcRn]
    -> TcM a
    -> TcM ([VarBndr TyVar flag], a)
    tcExplicitTKBndrsX SkolemMode
    skol_mode [LHsTyVarBndr Specificity GhcRn]
    bndrs TcM a
    thing_inside
                -- inv_tv_bndrs :: [VarBndr TyVar Specificity],
                -- but we want [VarBndr TyVar ArgFlag]
              ; ([TcTyVarBinder], a) -> TcM ([TcTyVarBinder], a)
    forall (m :: * -> *) a. Monad m => a -> m a
    return ([InvisTVBinder] -> [TcTyVarBinder]
    forall a. [VarBndr a Specificity] -> [VarBndr a ArgFlag]
    tyVarSpecToBinders [InvisTVBinder]
    inv_tv_bndrs, a
    thing) }
      where
        skol_mode :: SkolemMode
    skol_mode = SkolemMode
    smVanilla { sm_clone :: Bool
    sm_clone = Bool
    False, sm_holes :: HoleInfo
    sm_holes = TcTyMode -> HoleInfo
    mode_holes TcTyMode
    mode }

    --------------------------------------
    --    HsOuterTyVarBndrs
    --------------------------------------

    bindOuterTKBndrsX :: OutputableBndrFlag flag 'Renamed
                      => SkolemMode
                      -> HsOuterTyVarBndrs flag GhcRn
                      -> TcM a
                      -> TcM (HsOuterTyVarBndrs flag GhcTc, a)
    bindOuterTKBndrsX :: forall flag a.
    OutputableBndrFlag flag 'Renamed =>
    SkolemMode
    -> HsOuterTyVarBndrs flag GhcRn
    -> TcM a
    -> TcM (HsOuterTyVarBndrs flag GhcTc, a)
    bindOuterTKBndrsX SkolemMode
    skol_mode HsOuterTyVarBndrs flag GhcRn
    outer_bndrs TcM a
    thing_inside
      = case HsOuterTyVarBndrs flag GhcRn
    outer_bndrs of
          HsOuterImplicit{hso_ximplicit :: forall flag pass.
    HsOuterTyVarBndrs flag pass -> XHsOuterImplicit pass
    hso_ximplicit = XHsOuterImplicit GhcRn
    imp_tvs} ->
            do { ([TyVar]
    imp_tvs', a
    thing) <- SkolemMode -> HsQTvsRn -> TcM a -> TcM ([TyVar], a)
    forall a. SkolemMode -> HsQTvsRn -> TcM a -> TcM ([TyVar], a)
    bindImplicitTKBndrsX SkolemMode
    skol_mode HsQTvsRn
    XHsOuterImplicit GhcRn
    imp_tvs TcM a
    thing_inside
               ; (HsOuterTyVarBndrs flag GhcTc, a)
    -> TcM (HsOuterTyVarBndrs flag GhcTc, a)
    forall (m :: * -> *) a. Monad m => a -> m a
    return ( HsOuterImplicit{hso_ximplicit :: XHsOuterImplicit GhcTc
    hso_ximplicit = [TyVar]
    XHsOuterImplicit GhcTc
    imp_tvs'}
                        , a
    thing) }
          HsOuterExplicit{hso_bndrs :: forall flag pass.
    HsOuterTyVarBndrs flag pass -> [LHsTyVarBndr flag (NoGhcTc pass)]
    hso_bndrs = [LHsTyVarBndr flag (NoGhcTc GhcRn)]
    exp_bndrs} ->
            do { ([VarBndr TyVar flag]
    exp_tvs', a
    thing) <- SkolemMode
    -> [LHsTyVarBndr flag GhcRn]
    -> TcM a
    -> TcM ([VarBndr TyVar flag], a)
    forall flag a.
    OutputableBndrFlag flag 'Renamed =>
    SkolemMode
    -> [LHsTyVarBndr flag GhcRn]
    -> TcM a
    -> TcM ([VarBndr TyVar flag], a)
    bindExplicitTKBndrsX SkolemMode
    skol_mode [LHsTyVarBndr flag (NoGhcTc GhcRn)]
    [LHsTyVarBndr flag GhcRn]
    exp_bndrs TcM a
    thing_inside
               ; (HsOuterTyVarBndrs flag GhcTc, a)
    -> TcM (HsOuterTyVarBndrs flag GhcTc, a)
    forall (m :: * -> *) a. Monad m => a -> m a
    return ( HsOuterExplicit { hso_xexplicit :: XHsOuterExplicit GhcTc flag
    hso_xexplicit = [VarBndr TyVar flag]
    XHsOuterExplicit GhcTc flag
    exp_tvs'
                                          , hso_bndrs :: [LHsTyVarBndr flag (NoGhcTc GhcTc)]
    hso_bndrs     = [LHsTyVarBndr flag (NoGhcTc GhcRn)]
    [LHsTyVarBndr flag (NoGhcTc GhcTc)]
    exp_bndrs }
                        , a
    thing) }

    getOuterTyVars :: HsOuterTyVarBndrs flag GhcTc -> [TcTyVar]
    -- The returned [TcTyVar] is not necessarily in dependency order
    -- at least for the HsOuterImplicit case
    getOuterTyVars :: forall flag. HsOuterTyVarBndrs flag GhcTc -> [TyVar]
    getOuterTyVars (HsOuterImplicit { hso_ximplicit :: forall flag pass.
    HsOuterTyVarBndrs flag pass -> XHsOuterImplicit pass
    hso_ximplicit = XHsOuterImplicit GhcTc
    tvs })  = [TyVar]
    XHsOuterImplicit GhcTc
    tvs
    getOuterTyVars (HsOuterExplicit { hso_xexplicit :: forall flag pass.
    HsOuterTyVarBndrs flag pass -> XHsOuterExplicit pass flag
    hso_xexplicit = XHsOuterExplicit GhcTc flag
    tvbs }) = [VarBndr TyVar flag] -> [TyVar]
    forall tv argf. [VarBndr tv argf] -> [tv]
    binderVars [VarBndr TyVar flag]
    XHsOuterExplicit GhcTc flag
    tvbs

    ---------------
    scopedSortOuter :: HsOuterTyVarBndrs Specificity GhcTc -> TcM [InvisTVBinder]
    -- Sort any /implicit/ binders into dependency order
    --     (zonking first so we can see the dependencies)
    -- /Explicit/ ones are already in the right order
    scopedSortOuter :: HsOuterTyVarBndrs Specificity GhcTc -> TcM [InvisTVBinder]
    scopedSortOuter (HsOuterImplicit{hso_ximplicit :: forall flag pass.
    HsOuterTyVarBndrs flag pass -> XHsOuterImplicit pass
    hso_ximplicit = XHsOuterImplicit GhcTc
    imp_tvs})
      = do { [TyVar]
    imp_tvs <- [TyVar] -> TcM [TyVar]
    zonkAndScopedSort [TyVar]
    XHsOuterImplicit GhcTc
    imp_tvs
           ; [InvisTVBinder] -> TcM [InvisTVBinder]
    forall (m :: * -> *) a. Monad m => a -> m a
    return [TyVar -> Specificity -> InvisTVBinder
    forall var argf. var -> argf -> VarBndr var argf
    Bndr TyVar
    tv Specificity
    SpecifiedSpec | TyVar
    tv <- [TyVar]
    imp_tvs] }
    scopedSortOuter (HsOuterExplicit{hso_xexplicit :: forall flag pass.
    HsOuterTyVarBndrs flag pass -> XHsOuterExplicit pass flag
    hso_xexplicit = XHsOuterExplicit GhcTc Specificity
    exp_tvs})
      = -- No need to dependency-sort (or zonk) explicit quantifiers
        [InvisTVBinder] -> TcM [InvisTVBinder]
    forall (m :: * -> *) a. Monad m => a -> m a
    return [InvisTVBinder]
    XHsOuterExplicit GhcTc Specificity
    exp_tvs

    ---------------
    bindOuterSigTKBndrs_Tv :: HsOuterSigTyVarBndrs GhcRn
                           -> TcM a -> TcM (HsOuterSigTyVarBndrs GhcTc, a)
    bindOuterSigTKBndrs_Tv :: forall a.
    HsOuterSigTyVarBndrs GhcRn
    -> TcM a -> TcM (HsOuterTyVarBndrs Specificity GhcTc, a)
    bindOuterSigTKBndrs_Tv
      = SkolemMode
    -> HsOuterSigTyVarBndrs GhcRn
    -> TcM a
    -> TcM (HsOuterTyVarBndrs Specificity GhcTc, a)
    forall flag a.
    OutputableBndrFlag flag 'Renamed =>
    SkolemMode
    -> HsOuterTyVarBndrs flag GhcRn
    -> TcM a
    -> TcM (HsOuterTyVarBndrs flag GhcTc, a)
    bindOuterTKBndrsX (SkolemMode
    smVanilla { sm_clone :: Bool
    sm_clone = Bool
    True, sm_tvtv :: Bool
    sm_tvtv = Bool
    True })

    bindOuterSigTKBndrs_Tv_M :: TcTyMode
                             -> HsOuterSigTyVarBndrs GhcRn
                             -> TcM a -> TcM (HsOuterSigTyVarBndrs GhcTc, a)
    -- Do not push level; do not make implication constraint; use Tvs
    -- Two major clients of this "bind-only" path are:
    --    Note [Using TyVarTvs for kind-checking GADTs] in GHC.Tc.TyCl
    --    Note [Checking partial type signatures]
    bindOuterSigTKBndrs_Tv_M :: forall a.
    TcTyMode
    -> HsOuterSigTyVarBndrs GhcRn
    -> TcM a
    -> TcM (HsOuterTyVarBndrs Specificity GhcTc, a)
    bindOuterSigTKBndrs_Tv_M TcTyMode
    mode
      = SkolemMode
    -> HsOuterSigTyVarBndrs GhcRn
    -> TcM a
    -> TcM (HsOuterTyVarBndrs Specificity GhcTc, a)
    forall flag a.
    OutputableBndrFlag flag 'Renamed =>
    SkolemMode
    -> HsOuterTyVarBndrs flag GhcRn
    -> TcM a
    -> TcM (HsOuterTyVarBndrs flag GhcTc, a)
    bindOuterTKBndrsX (SkolemMode
    smVanilla { sm_clone :: Bool
    sm_clone = Bool
    True, sm_tvtv :: Bool
    sm_tvtv = Bool
    True
                                     , sm_holes :: HoleInfo
    sm_holes = TcTyMode -> HoleInfo
    mode_holes TcTyMode
    mode })

    bindOuterFamEqnTKBndrs_Q_Tv :: HsOuterFamEqnTyVarBndrs GhcRn
                                -> TcM a
                                -> TcM ([TcTyVar], a)
    bindOuterFamEqnTKBndrs_Q_Tv :: forall a.
    HsOuterFamEqnTyVarBndrs GhcRn -> TcM a -> TcM ([TyVar], a)
    bindOuterFamEqnTKBndrs_Q_Tv HsOuterFamEqnTyVarBndrs GhcRn
    hs_bndrs TcM a
    thing_inside
      = (HsOuterTyVarBndrs () GhcTc -> [TyVar])
    -> IOEnv (Env TcGblEnv TcLclEnv) (HsOuterTyVarBndrs () GhcTc, a)
    -> IOEnv (Env TcGblEnv TcLclEnv) ([TyVar], a)
    forall (m :: * -> *) a b r.
    Monad m =>
    (a -> b) -> m (a, r) -> m (b, r)
    liftFstM HsOuterTyVarBndrs () GhcTc -> [TyVar]
    forall flag. HsOuterTyVarBndrs flag GhcTc -> [TyVar]
    getOuterTyVars (IOEnv (Env TcGblEnv TcLclEnv) (HsOuterTyVarBndrs () GhcTc, a)
     -> IOEnv (Env TcGblEnv TcLclEnv) ([TyVar], a))
    -> IOEnv (Env TcGblEnv TcLclEnv) (HsOuterTyVarBndrs () GhcTc, a)
    -> IOEnv (Env TcGblEnv TcLclEnv) ([TyVar], a)
    forall a b. (a -> b) -> a -> b
    $
        SkolemMode
    -> HsOuterFamEqnTyVarBndrs GhcRn
    -> TcM a
    -> IOEnv (Env TcGblEnv TcLclEnv) (HsOuterTyVarBndrs () GhcTc, a)
    forall flag a.
    OutputableBndrFlag flag 'Renamed =>
    SkolemMode
    -> HsOuterTyVarBndrs flag GhcRn
    -> TcM a
    -> TcM (HsOuterTyVarBndrs flag GhcTc, a)
    bindOuterTKBndrsX (SkolemMode
    smVanilla { sm_clone :: Bool
    sm_clone = Bool
    False, sm_parent :: Bool
    sm_parent = Bool
    True
                                     , sm_tvtv :: Bool
    sm_tvtv = Bool
    True })
                          HsOuterFamEqnTyVarBndrs GhcRn
    hs_bndrs TcM a
    thing_inside
        -- sm_clone=False: see Note [Cloning for type variable binders]

    bindOuterFamEqnTKBndrs :: HsOuterFamEqnTyVarBndrs GhcRn
                           -> TcM a
                           -> TcM ([TcTyVar], a)
    bindOuterFamEqnTKBndrs :: forall a.
    HsOuterFamEqnTyVarBndrs GhcRn -> TcM a -> TcM ([TyVar], a)
    bindOuterFamEqnTKBndrs HsOuterFamEqnTyVarBndrs GhcRn
    hs_bndrs TcM a
    thing_inside
      = (HsOuterTyVarBndrs () GhcTc -> [TyVar])
    -> IOEnv (Env TcGblEnv TcLclEnv) (HsOuterTyVarBndrs () GhcTc, a)
    -> IOEnv (Env TcGblEnv TcLclEnv) ([TyVar], a)
    forall (m :: * -> *) a b r.
    Monad m =>
    (a -> b) -> m (a, r) -> m (b, r)
    liftFstM HsOuterTyVarBndrs () GhcTc -> [TyVar]
    forall flag. HsOuterTyVarBndrs flag GhcTc -> [TyVar]
    getOuterTyVars (IOEnv (Env TcGblEnv TcLclEnv) (HsOuterTyVarBndrs () GhcTc, a)
     -> IOEnv (Env TcGblEnv TcLclEnv) ([TyVar], a))
    -> IOEnv (Env TcGblEnv TcLclEnv) (HsOuterTyVarBndrs () GhcTc, a)
    -> IOEnv (Env TcGblEnv TcLclEnv) ([TyVar], a)
    forall a b. (a -> b) -> a -> b
    $
        SkolemMode
    -> HsOuterFamEqnTyVarBndrs GhcRn
    -> TcM a
    -> IOEnv (Env TcGblEnv TcLclEnv) (HsOuterTyVarBndrs () GhcTc, a)
    forall flag a.
    OutputableBndrFlag flag 'Renamed =>
    SkolemMode
    -> HsOuterTyVarBndrs flag GhcRn
    -> TcM a
    -> TcM (HsOuterTyVarBndrs flag GhcTc, a)
    bindOuterTKBndrsX (SkolemMode
    smVanilla { sm_clone :: Bool
    sm_clone = Bool
    False, sm_parent :: Bool
    sm_parent = Bool
    True })
                          HsOuterFamEqnTyVarBndrs GhcRn
    hs_bndrs TcM a
    thing_inside
        -- sm_clone=False: see Note [Cloning for type variable binders]

    ---------------
    tcOuterTKBndrs :: OutputableBndrFlag flag 'Renamed
                   => SkolemInfo
                   -> HsOuterTyVarBndrs flag GhcRn
                   -> TcM a -> TcM (HsOuterTyVarBndrs flag GhcTc, a)
    tcOuterTKBndrs :: forall flag a.
    OutputableBndrFlag flag 'Renamed =>
    SkolemInfo
    -> HsOuterTyVarBndrs flag GhcRn
    -> TcM a
    -> TcM (HsOuterTyVarBndrs flag GhcTc, a)
    tcOuterTKBndrs = SkolemMode
    -> SkolemInfo
    -> HsOuterTyVarBndrs flag GhcRn
    -> TcM a
    -> TcM (HsOuterTyVarBndrs flag GhcTc, a)
    forall flag a.
    OutputableBndrFlag flag 'Renamed =>
    SkolemMode
    -> SkolemInfo
    -> HsOuterTyVarBndrs flag GhcRn
    -> TcM a
    -> TcM (HsOuterTyVarBndrs flag GhcTc, a)
    tcOuterTKBndrsX (SkolemMode
    smVanilla { sm_clone :: Bool
    sm_clone = Bool
    False })
      -- Do not clone the outer binders
      -- See Note [Cloning for type variable binder] under "must not"

    tcOuterTKBndrsX :: OutputableBndrFlag flag 'Renamed
                    => SkolemMode -> SkolemInfo
                    -> HsOuterTyVarBndrs flag GhcRn
                    -> TcM a -> TcM (HsOuterTyVarBndrs flag GhcTc, a)
    -- Push level, capture constraints, make implication
    tcOuterTKBndrsX :: forall flag a.
    OutputableBndrFlag flag 'Renamed =>
    SkolemMode
    -> SkolemInfo
    -> HsOuterTyVarBndrs flag GhcRn
    -> TcM a
    -> TcM (HsOuterTyVarBndrs flag GhcTc, a)
    tcOuterTKBndrsX SkolemMode
    skol_mode SkolemInfo
    skol_info HsOuterTyVarBndrs flag GhcRn
    outer_bndrs TcM a
    thing_inside
      = case HsOuterTyVarBndrs flag GhcRn
    outer_bndrs of
          HsOuterImplicit{hso_ximplicit :: forall flag pass.
    HsOuterTyVarBndrs flag pass -> XHsOuterImplicit pass
    hso_ximplicit = XHsOuterImplicit GhcRn
    imp_tvs} ->
            do { ([TyVar]
    imp_tvs', a
    thing) <- SkolemMode -> SkolemInfo -> HsQTvsRn -> TcM a -> TcM ([TyVar], a)
    forall a.
    SkolemMode -> SkolemInfo -> HsQTvsRn -> TcM a -> TcM ([TyVar], a)
    tcImplicitTKBndrsX SkolemMode
    skol_mode SkolemInfo
    skol_info HsQTvsRn
    XHsOuterImplicit GhcRn
    imp_tvs TcM a
    thing_inside
               ; (HsOuterTyVarBndrs flag GhcTc, a)
    -> TcM (HsOuterTyVarBndrs flag GhcTc, a)
    forall (m :: * -> *) a. Monad m => a -> m a
    return ( HsOuterImplicit{hso_ximplicit :: XHsOuterImplicit GhcTc
    hso_ximplicit = [TyVar]
    XHsOuterImplicit GhcTc
    imp_tvs'}
                        , a
    thing) }
          HsOuterExplicit{hso_bndrs :: forall flag pass.
    HsOuterTyVarBndrs flag pass -> [LHsTyVarBndr flag (NoGhcTc pass)]
    hso_bndrs = [LHsTyVarBndr flag (NoGhcTc GhcRn)]
    exp_bndrs} ->
            do { ([VarBndr TyVar flag]
    exp_tvs', a
    thing) <- SkolemMode
    -> [LHsTyVarBndr flag GhcRn]
    -> TcM a
    -> TcM ([VarBndr TyVar flag], a)
    forall flag a.
    OutputableBndrFlag flag 'Renamed =>
    SkolemMode
    -> [LHsTyVarBndr flag GhcRn]
    -> TcM a
    -> TcM ([VarBndr TyVar flag], a)
    tcExplicitTKBndrsX SkolemMode
    skol_mode [LHsTyVarBndr flag (NoGhcTc GhcRn)]
    [LHsTyVarBndr flag GhcRn]
    exp_bndrs TcM a
    thing_inside
               ; (HsOuterTyVarBndrs flag GhcTc, a)
    -> TcM (HsOuterTyVarBndrs flag GhcTc, a)
    forall (m :: * -> *) a. Monad m => a -> m a
    return ( HsOuterExplicit { hso_xexplicit :: XHsOuterExplicit GhcTc flag
    hso_xexplicit = [VarBndr TyVar flag]
    XHsOuterExplicit GhcTc flag
    exp_tvs'
                                          , hso_bndrs :: [LHsTyVarBndr flag (NoGhcTc GhcTc)]
    hso_bndrs     = [LHsTyVarBndr flag (NoGhcTc GhcRn)]
    [LHsTyVarBndr flag (NoGhcTc GhcTc)]
    exp_bndrs }
                        , a
    thing) }

    --------------------------------------
    --    Explicit tyvar binders
    --------------------------------------

    tcExplicitTKBndrs :: OutputableBndrFlag flag 'Renamed
                      => [LHsTyVarBndr flag GhcRn]
                      -> TcM a
                      -> TcM ([VarBndr TyVar flag], a)
    tcExplicitTKBndrs :: forall flag a.
    OutputableBndrFlag flag 'Renamed =>
    [LHsTyVarBndr flag GhcRn] -> TcM a -> TcM ([VarBndr TyVar flag], a)
    tcExplicitTKBndrs = SkolemMode
    -> [LHsTyVarBndr flag GhcRn]
    -> TcM a
    -> TcM ([VarBndr TyVar flag], a)
    forall flag a.
    OutputableBndrFlag flag 'Renamed =>
    SkolemMode
    -> [LHsTyVarBndr flag GhcRn]
    -> TcM a
    -> TcM ([VarBndr TyVar flag], a)
    tcExplicitTKBndrsX (SkolemMode
    smVanilla { sm_clone :: Bool
    sm_clone = Bool
    True })

    tcExplicitTKBndrsX :: OutputableBndrFlag flag 'Renamed
                       => SkolemMode
                       -> [LHsTyVarBndr flag GhcRn]
                       -> TcM a
                       -> TcM ([VarBndr TyVar flag], a)
    -- Push level, capture constraints,
    -- and emit an implication constraint with a ForAllSkol ic_info,
    -- so that it is subject to a telescope test.
    tcExplicitTKBndrsX :: forall flag a.
    OutputableBndrFlag flag 'Renamed =>
    SkolemMode
    -> [LHsTyVarBndr flag GhcRn]
    -> TcM a
    -> TcM ([VarBndr TyVar flag], a)
    tcExplicitTKBndrsX SkolemMode
    skol_mode [LHsTyVarBndr flag GhcRn]
    bndrs TcM a
    thing_inside
      = do { (TcLevel
    tclvl, WantedConstraints
    wanted, ([VarBndr TyVar flag]
    skol_tvs, a
    res))
                 <- TcM ([VarBndr TyVar flag], a)
    -> TcM (TcLevel, WantedConstraints, ([VarBndr TyVar flag], a))
    forall a. TcM a -> TcM (TcLevel, WantedConstraints, a)
    pushLevelAndCaptureConstraints (TcM ([VarBndr TyVar flag], a)
     -> TcM (TcLevel, WantedConstraints, ([VarBndr TyVar flag], a)))
    -> TcM ([VarBndr TyVar flag], a)
    -> TcM (TcLevel, WantedConstraints, ([VarBndr TyVar flag], a))
    forall a b. (a -> b) -> a -> b
    $
                    SkolemMode
    -> [LHsTyVarBndr flag GhcRn]
    -> TcM a
    -> TcM ([VarBndr TyVar flag], a)
    forall flag a.
    OutputableBndrFlag flag 'Renamed =>
    SkolemMode
    -> [LHsTyVarBndr flag GhcRn]
    -> TcM a
    -> TcM ([VarBndr TyVar flag], a)
    bindExplicitTKBndrsX SkolemMode
    skol_mode [LHsTyVarBndr flag GhcRn]
    bndrs (TcM a -> TcM ([VarBndr TyVar flag], a))
    -> TcM a -> TcM ([VarBndr TyVar flag], a)
    forall a b. (a -> b) -> a -> b
    $
                    TcM a
    thing_inside

           ; let skol_info :: SkolemInfo
    skol_info = SDoc -> SkolemInfo
    ForAllSkol ([SDoc] -> SDoc
    fsep ((GenLocated SrcSpanAnnA (HsTyVarBndr flag GhcRn) -> SDoc)
    -> [GenLocated SrcSpanAnnA (HsTyVarBndr flag GhcRn)] -> [SDoc]
    forall a b. (a -> b) -> [a] -> [b]
    map GenLocated SrcSpanAnnA (HsTyVarBndr flag GhcRn) -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr [GenLocated SrcSpanAnnA (HsTyVarBndr flag GhcRn)]
    [LHsTyVarBndr flag GhcRn]
    bndrs))
                 -- Notice that we use ForAllSkol here, ignoring the enclosing
                 -- skol_info unlike tc_implicit_tk_bndrs, because the bad-telescope
                 -- test applies only to ForAllSkol
           ; SkolemInfo -> [TyVar] -> TcLevel -> WantedConstraints -> TcM ()
    emitResidualTvConstraint SkolemInfo
    skol_info ([VarBndr TyVar flag] -> [TyVar]
    forall tv argf. [VarBndr tv argf] -> [tv]
    binderVars [VarBndr TyVar flag]
    skol_tvs) TcLevel
    tclvl WantedConstraints
    wanted

           ; ([VarBndr TyVar flag], a) -> TcM ([VarBndr TyVar flag], a)
    forall (m :: * -> *) a. Monad m => a -> m a
    return ([VarBndr TyVar flag]
    skol_tvs, a
    res) }

    ----------------
    -- | Skolemise the 'HsTyVarBndr's in an 'HsForAllTelescope' with the supplied
    -- 'TcTyMode'.
    bindExplicitTKBndrs_Skol, bindExplicitTKBndrs_Tv
        :: (OutputableBndrFlag flag 'Renamed)
        => [LHsTyVarBndr flag GhcRn]
        -> TcM a
        -> TcM ([VarBndr TyVar flag], a)

    bindExplicitTKBndrs_Skol :: forall flag a.
    OutputableBndrFlag flag 'Renamed =>
    [LHsTyVarBndr flag GhcRn] -> TcM a -> TcM ([VarBndr TyVar flag], a)
    bindExplicitTKBndrs_Skol = SkolemMode
    -> [LHsTyVarBndr flag GhcRn]
    -> TcM a
    -> TcM ([VarBndr TyVar flag], a)
    forall flag a.
    OutputableBndrFlag flag 'Renamed =>
    SkolemMode
    -> [LHsTyVarBndr flag GhcRn]
    -> TcM a
    -> TcM ([VarBndr TyVar flag], a)
    bindExplicitTKBndrsX (SkolemMode
    smVanilla { sm_clone :: Bool
    sm_clone = Bool
    False })
    bindExplicitTKBndrs_Tv :: forall flag a.
    OutputableBndrFlag flag 'Renamed =>
    [LHsTyVarBndr flag GhcRn] -> TcM a -> TcM ([VarBndr TyVar flag], a)
    bindExplicitTKBndrs_Tv   = SkolemMode
    -> [LHsTyVarBndr flag GhcRn]
    -> TcM a
    -> TcM ([VarBndr TyVar flag], a)
    forall flag a.
    OutputableBndrFlag flag 'Renamed =>
    SkolemMode
    -> [LHsTyVarBndr flag GhcRn]
    -> TcM a
    -> TcM ([VarBndr TyVar flag], a)
    bindExplicitTKBndrsX (SkolemMode
    smVanilla { sm_clone :: Bool
    sm_clone = Bool
    True, sm_tvtv :: Bool
    sm_tvtv = Bool
    True })
       -- sm_clone: see Note [Cloning for type variable binders]

    bindExplicitTKBndrs_Q_Skol, bindExplicitTKBndrs_Q_Tv
        :: ContextKind
        -> [LHsTyVarBndr () GhcRn]
        -> TcM a
        -> TcM ([TcTyVar], a)
    -- These do not clone: see Note [Cloning for type variable binders]
    bindExplicitTKBndrs_Q_Skol :: forall a.
    ContextKind -> [LHsTyVarBndr () GhcRn] -> TcM a -> TcM ([TyVar], a)
    bindExplicitTKBndrs_Q_Skol ContextKind
    ctxt_kind [LHsTyVarBndr () GhcRn]
    hs_bndrs TcM a
    thing_inside
      = ([VarBndr TyVar ()] -> [TyVar])
    -> IOEnv (Env TcGblEnv TcLclEnv) ([VarBndr TyVar ()], a)
    -> IOEnv (Env TcGblEnv TcLclEnv) ([TyVar], a)
    forall (m :: * -> *) a b r.
    Monad m =>
    (a -> b) -> m (a, r) -> m (b, r)
    liftFstM [VarBndr TyVar ()] -> [TyVar]
    forall tv argf. [VarBndr tv argf] -> [tv]
    binderVars (IOEnv (Env TcGblEnv TcLclEnv) ([VarBndr TyVar ()], a)
     -> IOEnv (Env TcGblEnv TcLclEnv) ([TyVar], a))
    -> IOEnv (Env TcGblEnv TcLclEnv) ([VarBndr TyVar ()], a)
    -> IOEnv (Env TcGblEnv TcLclEnv) ([TyVar], a)
    forall a b. (a -> b) -> a -> b
    $
        SkolemMode
    -> [LHsTyVarBndr () GhcRn]
    -> TcM a
    -> IOEnv (Env TcGblEnv TcLclEnv) ([VarBndr TyVar ()], a)
    forall flag a.
    OutputableBndrFlag flag 'Renamed =>
    SkolemMode
    -> [LHsTyVarBndr flag GhcRn]
    -> TcM a
    -> TcM ([VarBndr TyVar flag], a)
    bindExplicitTKBndrsX (SkolemMode
    smVanilla { sm_clone :: Bool
    sm_clone = Bool
    False, sm_parent :: Bool
    sm_parent = Bool
    True
                                        , sm_kind :: ContextKind
    sm_kind = ContextKind
    ctxt_kind })
                             [LHsTyVarBndr () GhcRn]
    hs_bndrs TcM a
    thing_inside
        -- sm_clone=False: see Note [Cloning for type variable binders]

    bindExplicitTKBndrs_Q_Tv :: forall a.
    ContextKind -> [LHsTyVarBndr () GhcRn] -> TcM a -> TcM ([TyVar], a)
    bindExplicitTKBndrs_Q_Tv ContextKind
    ctxt_kind [LHsTyVarBndr () GhcRn]
    hs_bndrs TcM a
    thing_inside
      = ([VarBndr TyVar ()] -> [TyVar])
    -> IOEnv (Env TcGblEnv TcLclEnv) ([VarBndr TyVar ()], a)
    -> IOEnv (Env TcGblEnv TcLclEnv) ([TyVar], a)
    forall (m :: * -> *) a b r.
    Monad m =>
    (a -> b) -> m (a, r) -> m (b, r)
    liftFstM [VarBndr TyVar ()] -> [TyVar]
    forall tv argf. [VarBndr tv argf] -> [tv]
    binderVars (IOEnv (Env TcGblEnv TcLclEnv) ([VarBndr TyVar ()], a)
     -> IOEnv (Env TcGblEnv TcLclEnv) ([TyVar], a))
    -> IOEnv (Env TcGblEnv TcLclEnv) ([VarBndr TyVar ()], a)
    -> IOEnv (Env TcGblEnv TcLclEnv) ([TyVar], a)
    forall a b. (a -> b) -> a -> b
    $
        SkolemMode
    -> [LHsTyVarBndr () GhcRn]
    -> TcM a
    -> IOEnv (Env TcGblEnv TcLclEnv) ([VarBndr TyVar ()], a)
    forall flag a.
    OutputableBndrFlag flag 'Renamed =>
    SkolemMode
    -> [LHsTyVarBndr flag GhcRn]
    -> TcM a
    -> TcM ([VarBndr TyVar flag], a)
    bindExplicitTKBndrsX (SkolemMode
    smVanilla { sm_clone :: Bool
    sm_clone = Bool
    False, sm_parent :: Bool
    sm_parent = Bool
    True
                                        , sm_tvtv :: Bool
    sm_tvtv = Bool
    True, sm_kind :: ContextKind
    sm_kind = ContextKind
    ctxt_kind })
                             [LHsTyVarBndr () GhcRn]
    hs_bndrs TcM a
    thing_inside
        -- sm_clone=False: see Note [Cloning for type variable binders]

    bindExplicitTKBndrsX :: (OutputableBndrFlag flag 'Renamed)
        => SkolemMode
        -> [LHsTyVarBndr flag GhcRn]
        -> TcM a
        -> TcM ([VarBndr TyVar flag], a)  -- Returned [TcTyVar] are in 1-1 correspondence
                                          -- with the passed-in [LHsTyVarBndr]
    bindExplicitTKBndrsX :: forall flag a.
    OutputableBndrFlag flag 'Renamed =>
    SkolemMode
    -> [LHsTyVarBndr flag GhcRn]
    -> TcM a
    -> TcM ([VarBndr TyVar flag], a)
    bindExplicitTKBndrsX skol_mode :: SkolemMode
    skol_mode@(SM { sm_parent :: SkolemMode -> Bool
    sm_parent = Bool
    check_parent, sm_kind :: SkolemMode -> ContextKind
    sm_kind = ContextKind
    ctxt_kind
                                       , sm_holes :: SkolemMode -> HoleInfo
    sm_holes = HoleInfo
    hole_info })
                         [LHsTyVarBndr flag GhcRn]
    hs_tvs TcM a
    thing_inside
      = do { String -> SDoc -> TcM ()
    traceTc String
    "bindExplicitTKBndrs" ([GenLocated SrcSpanAnnA (HsTyVarBndr flag GhcRn)] -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr [GenLocated SrcSpanAnnA (HsTyVarBndr flag GhcRn)]
    [LHsTyVarBndr flag GhcRn]
    hs_tvs)
           ; [GenLocated SrcSpanAnnA (HsTyVarBndr flag GhcRn)]
    -> TcM ([VarBndr TyVar flag], a)
    go [GenLocated SrcSpanAnnA (HsTyVarBndr flag GhcRn)]
    [LHsTyVarBndr flag GhcRn]
    hs_tvs }
      where
        tc_ki_mode :: TcTyMode
    tc_ki_mode = TcTyMode { mode_tyki :: TypeOrKind
    mode_tyki = TypeOrKind
    KindLevel, mode_holes :: HoleInfo
    mode_holes = HoleInfo
    hole_info }
                     -- Inherit the HoleInfo from the context

        go :: [GenLocated SrcSpanAnnA (HsTyVarBndr flag GhcRn)]
    -> TcM ([VarBndr TyVar flag], a)
    go [] = do { a
    res <- TcM a
    thing_inside
                   ; ([VarBndr TyVar flag], a) -> TcM ([VarBndr TyVar flag], a)
    forall (m :: * -> *) a. Monad m => a -> m a
    return ([], a
    res) }
        go (L SrcSpanAnnA
    _ HsTyVarBndr flag GhcRn
    hs_tv : [GenLocated SrcSpanAnnA (HsTyVarBndr flag GhcRn)]
    hs_tvs)
           = do { NameEnv TcTyThing
    lcl_env <- TcM (NameEnv TcTyThing)
    getLclTypeEnv
                ; TyVar
    tv <- NameEnv TcTyThing
    -> HsTyVarBndr flag GhcRn -> IOEnv (Env TcGblEnv TcLclEnv) TyVar
    tc_hs_bndr NameEnv TcTyThing
    lcl_env HsTyVarBndr flag GhcRn
    hs_tv
                -- Extend the environment as we go, in case a binder
                -- is mentioned in the kind of a later binder
                --   e.g. forall k (a::k). blah
                -- NB: tv's Name may differ from hs_tv's
                -- See Note [Cloning for type variable binders]
                ; ([VarBndr TyVar flag]
    tvs,a
    res) <- [(Name, TyVar)]
    -> TcM ([VarBndr TyVar flag], a) -> TcM ([VarBndr TyVar flag], a)
    forall r. [(Name, TyVar)] -> TcM r -> TcM r
    tcExtendNameTyVarEnv [(HsTyVarBndr flag GhcRn -> IdP GhcRn
    forall flag (p :: Pass).
    HsTyVarBndr flag (GhcPass p) -> IdP (GhcPass p)
    hsTyVarName HsTyVarBndr flag GhcRn
    hs_tv, TyVar
    tv)] (TcM ([VarBndr TyVar flag], a) -> TcM ([VarBndr TyVar flag], a))
    -> TcM ([VarBndr TyVar flag], a) -> TcM ([VarBndr TyVar flag], a)
    forall a b. (a -> b) -> a -> b
    $
                               [GenLocated SrcSpanAnnA (HsTyVarBndr flag GhcRn)]
    -> TcM ([VarBndr TyVar flag], a)
    go [GenLocated SrcSpanAnnA (HsTyVarBndr flag GhcRn)]
    hs_tvs
                ; ([VarBndr TyVar flag], a) -> TcM ([VarBndr TyVar flag], a)
    forall (m :: * -> *) a. Monad m => a -> m a
    return (TyVar -> flag -> VarBndr TyVar flag
    forall var argf. var -> argf -> VarBndr var argf
    Bndr TyVar
    tv (HsTyVarBndr flag GhcRn -> flag
    forall flag (pass :: Pass). HsTyVarBndr flag (GhcPass pass) -> flag
    hsTyVarBndrFlag HsTyVarBndr flag GhcRn
    hs_tv)VarBndr TyVar flag -> [VarBndr TyVar flag] -> [VarBndr TyVar flag]
    forall a. a -> [a] -> [a]
    :[VarBndr TyVar flag]
    tvs, a
    res) }

        tc_hs_bndr :: NameEnv TcTyThing
    -> HsTyVarBndr flag GhcRn -> IOEnv (Env TcGblEnv TcLclEnv) TyVar
    tc_hs_bndr NameEnv TcTyThing
    lcl_env (UserTyVar XUserTyVar GhcRn
    _ flag
    _ (L Anno (IdGhcP 'Renamed)
    _ Name
    name))
          | Bool
    check_parent
          , Just (ATyVar Name
    _ TyVar
    tv) <- NameEnv TcTyThing -> Name -> Maybe TcTyThing
    forall a. NameEnv a -> Name -> Maybe a
    lookupNameEnv NameEnv TcTyThing
    lcl_env Name
    name
          = TyVar -> IOEnv (Env TcGblEnv TcLclEnv) TyVar
    forall (m :: * -> *) a. Monad m => a -> m a
    return TyVar
    tv
          | Bool
    otherwise
          = do { Type
    kind <- ContextKind -> TcM Type
    newExpectedKind ContextKind
    ctxt_kind
               ; SkolemMode -> Name -> Type -> IOEnv (Env TcGblEnv TcLclEnv) TyVar
    newTyVarBndr SkolemMode
    skol_mode Name
    name Type
    kind }

        tc_hs_bndr NameEnv TcTyThing
    lcl_env (KindedTyVar XKindedTyVar GhcRn
    _ flag
    _ (L Anno (IdGhcP 'Renamed)
    _ Name
    name) LHsType GhcRn
    lhs_kind)
          | Bool
    check_parent
          , Just (ATyVar Name
    _ TyVar
    tv) <- NameEnv TcTyThing -> Name -> Maybe TcTyThing
    forall a. NameEnv a -> Name -> Maybe a
    lookupNameEnv NameEnv TcTyThing
    lcl_env Name
    name
          = do { Type
    kind <- TcTyMode -> UserTypeCtxt -> LHsType GhcRn -> TcM Type
    tc_lhs_kind_sig TcTyMode
    tc_ki_mode (Name -> UserTypeCtxt
    TyVarBndrKindCtxt Name
    name) LHsType GhcRn
    lhs_kind
               ; TcM Coercion -> TcM ()
    forall a. TcM a -> TcM ()
    discardResult (TcM Coercion -> TcM ()) -> TcM Coercion -> TcM ()
    forall a b. (a -> b) -> a -> b
    $
                 Maybe SDoc -> Type -> Type -> TcM Coercion
    unifyKind (SDoc -> Maybe SDoc
    forall a. a -> Maybe a
    Just (Name -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr Name
    name)) Type
    kind (TyVar -> Type
    tyVarKind TyVar
    tv)
                              -- This unify rejects:
                              --    class C (m :: * -> *) where
                              --      type F (m :: *) = ...
               ; TyVar -> IOEnv (Env TcGblEnv TcLclEnv) TyVar
    forall (m :: * -> *) a. Monad m => a -> m a
    return TyVar
    tv }

          | Bool
    otherwise
          = do { Type
    kind <- TcTyMode -> UserTypeCtxt -> LHsType GhcRn -> TcM Type
    tc_lhs_kind_sig TcTyMode
    tc_ki_mode (Name -> UserTypeCtxt
    TyVarBndrKindCtxt Name
    name) LHsType GhcRn
    lhs_kind
               ; SkolemMode -> Name -> Type -> IOEnv (Env TcGblEnv TcLclEnv) TyVar
    newTyVarBndr SkolemMode
    skol_mode Name
    name Type
    kind }

    newTyVarBndr :: SkolemMode -> Name -> Kind -> TcM TcTyVar
    newTyVarBndr :: SkolemMode -> Name -> Type -> IOEnv (Env TcGblEnv TcLclEnv) TyVar
    newTyVarBndr (SM { sm_clone :: SkolemMode -> Bool
    sm_clone = Bool
    clone, sm_tvtv :: SkolemMode -> Bool
    sm_tvtv = Bool
    tvtv }) Name
    name Type
    kind
      = do { Name
    name <- case Bool
    clone of
                  Bool
    True -> do { Unique
    uniq <- TcRnIf TcGblEnv TcLclEnv Unique
    forall gbl lcl. TcRnIf gbl lcl Unique
    newUnique
                             ; Name -> TcM Name
    forall (m :: * -> *) a. Monad m => a -> m a
    return (Name -> Unique -> Name
    setNameUnique Name
    name Unique
    uniq) }
                  Bool
    False -> Name -> TcM Name
    forall (m :: * -> *) a. Monad m => a -> m a
    return Name
    name
           ; TcTyVarDetails
    details <- case Bool
    tvtv of
                     Bool
    True  -> MetaInfo -> TcM TcTyVarDetails
    newMetaDetails MetaInfo
    TyVarTv
                     Bool
    False -> do { TcLevel
    lvl <- TcM TcLevel
    getTcLevel
                                 ; TcTyVarDetails -> TcM TcTyVarDetails
    forall (m :: * -> *) a. Monad m => a -> m a
    return (TcLevel -> Bool -> TcTyVarDetails
    SkolemTv TcLevel
    lvl Bool
    False) }
           ; TyVar -> IOEnv (Env TcGblEnv TcLclEnv) TyVar
    forall (m :: * -> *) a. Monad m => a -> m a
    return (Name -> Type -> TcTyVarDetails -> TyVar
    mkTcTyVar Name
    name Type
    kind TcTyVarDetails
    details) }

    --------------------------------------
    --    Implicit tyvar binders
    --------------------------------------

    tcImplicitTKBndrsX :: SkolemMode -> SkolemInfo
                       -> [Name]
                       -> TcM a
                       -> TcM ([TcTyVar], a)
    -- The workhorse:
    --    push level, capture constraints,
    --    and emit an implication constraint with a ForAllSkol ic_info,
    --    so that it is subject to a telescope test.
    tcImplicitTKBndrsX :: forall a.
    SkolemMode -> SkolemInfo -> HsQTvsRn -> TcM a -> TcM ([TyVar], a)
    tcImplicitTKBndrsX SkolemMode
    skol_mode SkolemInfo
    skol_info HsQTvsRn
    bndrs TcM a
    thing_inside
      = do { (TcLevel
    tclvl, WantedConstraints
    wanted, ([TyVar]
    skol_tvs, a
    res))
                 <- TcM ([TyVar], a) -> TcM (TcLevel, WantedConstraints, ([TyVar], a))
    forall a. TcM a -> TcM (TcLevel, WantedConstraints, a)
    pushLevelAndCaptureConstraints       (TcM ([TyVar], a)
     -> TcM (TcLevel, WantedConstraints, ([TyVar], a)))
    -> TcM ([TyVar], a)
    -> TcM (TcLevel, WantedConstraints, ([TyVar], a))
    forall a b. (a -> b) -> a -> b
    $
                    SkolemMode -> HsQTvsRn -> TcM a -> TcM ([TyVar], a)
    forall a. SkolemMode -> HsQTvsRn -> TcM a -> TcM ([TyVar], a)
    bindImplicitTKBndrsX SkolemMode
    skol_mode HsQTvsRn
    bndrs (TcM a -> TcM ([TyVar], a)) -> TcM a -> TcM ([TyVar], a)
    forall a b. (a -> b) -> a -> b
    $
                    TcM a
    thing_inside

           ; SkolemInfo -> [TyVar] -> TcLevel -> WantedConstraints -> TcM ()
    emitResidualTvConstraint SkolemInfo
    skol_info [TyVar]
    skol_tvs TcLevel
    tclvl WantedConstraints
    wanted

           ; ([TyVar], a) -> TcM ([TyVar], a)
    forall (m :: * -> *) a. Monad m => a -> m a
    return ([TyVar]
    skol_tvs, a
    res) }

    ------------------
    bindImplicitTKBndrs_Skol, bindImplicitTKBndrs_Tv,
      bindImplicitTKBndrs_Q_Skol, bindImplicitTKBndrs_Q_Tv
      :: [Name] -> TcM a -> TcM ([TcTyVar], a)
    bindImplicitTKBndrs_Skol :: forall a. HsQTvsRn -> TcM a -> TcM ([TyVar], a)
    bindImplicitTKBndrs_Skol   = SkolemMode -> HsQTvsRn -> TcM a -> TcM ([TyVar], a)
    forall a. SkolemMode -> HsQTvsRn -> TcM a -> TcM ([TyVar], a)
    bindImplicitTKBndrsX (SkolemMode
    smVanilla { sm_clone :: Bool
    sm_clone = Bool
    True })
    bindImplicitTKBndrs_Tv :: forall a. HsQTvsRn -> TcM a -> TcM ([TyVar], a)
    bindImplicitTKBndrs_Tv     = SkolemMode -> HsQTvsRn -> TcM a -> TcM ([TyVar], a)
    forall a. SkolemMode -> HsQTvsRn -> TcM a -> TcM ([TyVar], a)
    bindImplicitTKBndrsX (SkolemMode
    smVanilla { sm_clone :: Bool
    sm_clone = Bool
    True, sm_tvtv :: Bool
    sm_tvtv = Bool
    True })
    bindImplicitTKBndrs_Q_Skol :: forall a. HsQTvsRn -> TcM a -> TcM ([TyVar], a)
    bindImplicitTKBndrs_Q_Skol = SkolemMode -> HsQTvsRn -> TcM a -> TcM ([TyVar], a)
    forall a. SkolemMode -> HsQTvsRn -> TcM a -> TcM ([TyVar], a)
    bindImplicitTKBndrsX (SkolemMode
    smVanilla { sm_clone :: Bool
    sm_clone = Bool
    False, sm_parent :: Bool
    sm_parent = Bool
    True })
    bindImplicitTKBndrs_Q_Tv :: forall a. HsQTvsRn -> TcM a -> TcM ([TyVar], a)
    bindImplicitTKBndrs_Q_Tv   = SkolemMode -> HsQTvsRn -> TcM a -> TcM ([TyVar], a)
    forall a. SkolemMode -> HsQTvsRn -> TcM a -> TcM ([TyVar], a)
    bindImplicitTKBndrsX (SkolemMode
    smVanilla { sm_clone :: Bool
    sm_clone = Bool
    False, sm_parent :: Bool
    sm_parent = Bool
    True, sm_tvtv :: Bool
    sm_tvtv = Bool
    True })

    bindImplicitTKBndrsX
       :: SkolemMode
       -> [Name]
       -> TcM a
       -> TcM ([TcTyVar], a)   -- Returned [TcTyVar] are in 1-1 correspondence
                               -- with the passed in [Name]
    bindImplicitTKBndrsX :: forall a. SkolemMode -> HsQTvsRn -> TcM a -> TcM ([TyVar], a)
    bindImplicitTKBndrsX skol_mode :: SkolemMode
    skol_mode@(SM { sm_parent :: SkolemMode -> Bool
    sm_parent = Bool
    check_parent, sm_kind :: SkolemMode -> ContextKind
    sm_kind = ContextKind
    ctxt_kind })
                         HsQTvsRn
    tv_names TcM a
    thing_inside
      = do { NameEnv TcTyThing
    lcl_env <- TcM (NameEnv TcTyThing)
    getLclTypeEnv
           ; [TyVar]
    tkvs <- (Name -> IOEnv (Env TcGblEnv TcLclEnv) TyVar)
    -> HsQTvsRn -> TcM [TyVar]
    forall (t :: * -> *) (m :: * -> *) a b.
    (Traversable t, Monad m) =>
    (a -> m b) -> t a -> m (t b)
    mapM (NameEnv TcTyThing -> Name -> IOEnv (Env TcGblEnv TcLclEnv) TyVar
    new_tv NameEnv TcTyThing
    lcl_env) HsQTvsRn
    tv_names
           ; String -> SDoc -> TcM ()
    traceTc String
    "bindImplicitTKBndrsX" (HsQTvsRn -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr HsQTvsRn
    tv_names SDoc -> SDoc -> SDoc
    $$ [TyVar] -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr [TyVar]
    tkvs)
           ; a
    res <- [(Name, TyVar)] -> TcM a -> TcM a
    forall r. [(Name, TyVar)] -> TcM r -> TcM r
    tcExtendNameTyVarEnv (HsQTvsRn
    tv_names HsQTvsRn -> [TyVar] -> [(Name, TyVar)]
    forall a b. [a] -> [b] -> [(a, b)]
    `zip` [TyVar]
    tkvs)
                    TcM a
    thing_inside
           ; ([TyVar], a) -> TcM ([TyVar], a)
    forall (m :: * -> *) a. Monad m => a -> m a
    return ([TyVar]
    tkvs, a
    res) }
      where
        new_tv :: NameEnv TcTyThing -> Name -> IOEnv (Env TcGblEnv TcLclEnv) TyVar
    new_tv NameEnv TcTyThing
    lcl_env Name
    name
          | Bool
    check_parent
          , Just (ATyVar Name
    _ TyVar
    tv) <- NameEnv TcTyThing -> Name -> Maybe TcTyThing
    forall a. NameEnv a -> Name -> Maybe a
    lookupNameEnv NameEnv TcTyThing
    lcl_env Name
    name
          = TyVar -> IOEnv (Env TcGblEnv TcLclEnv) TyVar
    forall (m :: * -> *) a. Monad m => a -> m a
    return TyVar
    tv
          | Bool
    otherwise
          = do { Type
    kind <- ContextKind -> TcM Type
    newExpectedKind ContextKind
    ctxt_kind
               ; SkolemMode -> Name -> Type -> IOEnv (Env TcGblEnv TcLclEnv) TyVar
    newTyVarBndr SkolemMode
    skol_mode Name
    name Type
    kind }

    --------------------------------------
    --           SkolemMode
    --------------------------------------

    -- | 'SkolemMode' describes how to typecheck an explicit ('HsTyVarBndr') or
    -- implicit ('Name') binder in a type. It is just a record of flags
    -- that describe what sort of 'TcTyVar' to create.
    data SkolemMode
      = SM { SkolemMode -> Bool
    sm_parent :: Bool    -- True <=> check the in-scope parent type variable
                                  -- Used only for asssociated types

           , SkolemMode -> Bool
    sm_clone  :: Bool    -- True <=> fresh unique
                                  -- See Note [Cloning for type variable binders]

           , SkolemMode -> Bool
    sm_tvtv   :: Bool    -- True <=> use a TyVarTv, rather than SkolemTv
                                  -- Why?  See Note [Inferring kinds for type declarations]
                                  -- in GHC.Tc.TyCl, and (in this module)
                                  -- Note [Checking partial type signatures]

           , SkolemMode -> ContextKind
    sm_kind   :: ContextKind  -- Use this for the kind of any new binders

           , SkolemMode -> HoleInfo
    sm_holes  :: HoleInfo     -- What to do for wildcards in the kind
           }

    smVanilla :: SkolemMode
    smVanilla :: SkolemMode
    smVanilla = SM { sm_clone :: Bool
    sm_clone  = String -> Bool
    forall a. String -> a
    panic String
    "sm_clone"  -- We always override this
                   , sm_parent :: Bool
    sm_parent = Bool
    False
                   , sm_tvtv :: Bool
    sm_tvtv   = Bool
    False
                   , sm_kind :: ContextKind
    sm_kind   = ContextKind
    AnyKind
                   , sm_holes :: HoleInfo
    sm_holes  = HoleInfo
    forall a. Maybe a
    Nothing }

    {- Note [Cloning for type variable binders]
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    Sometimes we must clone the Name of a type variable binder (written in
    the source program); and sometimes we must not. This is controlled by
    the sm_clone field of SkolemMode.

    In some cases it doesn't matter whether or not we clone. Perhaps
    it'd be better to use MustClone/MayClone/MustNotClone.

    When we /must not/ clone
    * In the binders of a type signature (tcOuterTKBndrs)
          f :: forall a{27}. blah
          f = rhs
      Then 'a' scopes over 'rhs'. When we kind-check the signature (tcHsSigType),
      we must get the type (forall a{27}. blah) for the Id f, because
      we bring that type variable into scope when we typecheck 'rhs'.

    * In the binders of a data family instance (bindOuterFamEqnTKBndrs)
         data instance
           forall p q. D (p,q) = D1 p | D2 q
      We kind-check the LHS in tcDataFamInstHeader, and then separately
      (in tcDataFamInstDecl) bring p,q into scope before looking at the
      the constructor decls.

    * bindExplicitTKBndrs_Q_Tv/bindImplicitTKBndrs_Q_Tv do not clone
      We take advantage of this in kcInferDeclHeader:
         all_tv_prs = mkTyVarNamePairs (scoped_kvs ++ tc_tvs)
      If we cloned, we'd need to take a bit more care here; not hard.

    * bindExplicitTKBndrs_Q_Skol, bindExplicitTKBndrs_Skol, do not clone.
      There is no need, I think.

      The payoff here is that avoiding gratuitous cloning means that we can
      almost always take the fast path in swizzleTcTyConBndrs.

    When we /must/ clone.
    * bindOuterSigTKBndrs_Tv, bindExplicitTKBndrs_Tv do cloning

      This for a narrow and tricky reason which, alas, I couldn't find a
      simpler way round.  #16221 is the poster child:

         data SameKind :: k -> k -> *
         data T a = forall k2 (b :: k2). MkT (SameKind a b) !Int

      When kind-checking T, we give (a :: kappa1). Then:

      - In kcConDecl we make a TyVarTv unification variable kappa2 for k2
        (as described in Note [Using TyVarTvs for kind-checking GADTs],
        even though this example is an existential)
      - So we get (b :: kappa2) via bindExplicitTKBndrs_Tv
      - We end up unifying kappa1 := kappa2, because of the (SameKind a b)

      Now we generalise over kappa2. But if kappa2's Name is precisely k2
      (i.e. we did not clone) we'll end up giving T the utterly final kind
        T :: forall k2. k2 -> *
      Nothing directly wrong with that but when we typecheck the data constructor
      we have k2 in scope; but then it's brought into scope /again/ when we find
      the forall k2.  This is chaotic, and we end up giving it the type
        MkT :: forall k2 (a :: k2) k2 (b :: k2).
               SameKind @k2 a b -> Int -> T @{k2} a
      which is bogus -- because of the shadowing of k2, we can't
      apply T to the kind or a!

      And there no reason /not/ to clone the Name when making a unification
      variable.  So that's what we do.
    -}

    --------------------------------------
    -- Binding type/class variables in the
    -- kind-checking and typechecking phases
    --------------------------------------

    bindTyClTyVars :: Name
                   -> (TcTyCon -> [TyConBinder] -> Kind -> TcM a) -> TcM a
    -- ^ Used for the type variables of a type or class decl
    -- in the "kind checking" and "type checking" pass,
    -- but not in the initial-kind run.
    bindTyClTyVars :: forall a.
    Name -> (TyCon -> [TyConBinder] -> Type -> TcM a) -> TcM a
    bindTyClTyVars Name
    tycon_name TyCon -> [TyConBinder] -> Type -> TcM a
    thing_inside
      = do { TyCon
    tycon <- HasDebugCallStack => Name -> TcM TyCon
    Name -> TcM TyCon
    tcLookupTcTyCon Name
    tycon_name
           ; let scoped_prs :: [(Name, TyVar)]
    scoped_prs = TyCon -> [(Name, TyVar)]
    tcTyConScopedTyVars TyCon
    tycon
                 res_kind :: Type
    res_kind   = TyCon -> Type
    tyConResKind TyCon
    tycon
                 binders :: [TyConBinder]
    binders    = TyCon -> [TyConBinder]
    tyConBinders TyCon
    tycon
           ; String -> SDoc -> TcM ()
    traceTc String
    "bindTyClTyVars" (Name -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr Name
    tycon_name SDoc -> SDoc -> SDoc
    <+> [TyConBinder] -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr [TyConBinder]
    binders SDoc -> SDoc -> SDoc
    $$ [(Name, TyVar)] -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr [(Name, TyVar)]
    scoped_prs)
           ; [(Name, TyVar)] -> TcM a -> TcM a
    forall r. [(Name, TyVar)] -> TcM r -> TcM r
    tcExtendNameTyVarEnv [(Name, TyVar)]
    scoped_prs (TcM a -> TcM a) -> TcM a -> TcM a
    forall a b. (a -> b) -> a -> b
    $
             TyCon -> [TyConBinder] -> Type -> TcM a
    thing_inside TyCon
    tycon [TyConBinder]
    binders Type
    res_kind }

    {- *********************************************************************
    *                                                                      *
                 Kind generalisation
    *                                                                      *
    ********************************************************************* -}

    zonkAndScopedSort :: [TcTyVar] -> TcM [TcTyVar]
    zonkAndScopedSort :: [TyVar] -> TcM [TyVar]
    zonkAndScopedSort [TyVar]
    spec_tkvs
      = do { [TyVar]
    spec_tkvs <- (TyVar -> IOEnv (Env TcGblEnv TcLclEnv) TyVar)
    -> [TyVar] -> TcM [TyVar]
    forall (t :: * -> *) (m :: * -> *) a b.
    (Traversable t, Monad m) =>
    (a -> m b) -> t a -> m (t b)
    mapM HasDebugCallStack => TyVar -> IOEnv (Env TcGblEnv TcLclEnv) TyVar
    TyVar -> IOEnv (Env TcGblEnv TcLclEnv) TyVar
    zonkTcTyVarToTyVar [TyVar]
    spec_tkvs
             -- Zonk the kinds, to we can do the dependency analayis

           -- Do a stable topological sort, following
           -- Note [Ordering of implicit variables] in GHC.Rename.HsType
           ; [TyVar] -> TcM [TyVar]
    forall (m :: * -> *) a. Monad m => a -> m a
    return ([TyVar] -> [TyVar]
    scopedSort [TyVar]
    spec_tkvs) }

    -- | Generalize some of the free variables in the given type.
    -- All such variables should be *kind* variables; any type variables
    -- should be explicitly quantified (with a `forall`) before now.
    --
    -- The WantedConstraints are un-solved kind constraints. Generally
    -- they'll be reported as errors later, but meanwhile we refrain
    -- from quantifying over any variable free in these unsolved
    -- constraints. See Note [Failure in local type signatures].
    --
    -- But in all cases, generalize only those variables whose TcLevel is
    -- strictly greater than the ambient level. This "strictly greater
    -- than" means that you likely need to push the level before creating
    -- whatever type gets passed here.
    --
    -- Any variable whose level is greater than the ambient level but is
    -- not selected to be generalized will be promoted. (See [Promoting
    -- unification variables] in "GHC.Tc.Solver" and Note [Recipe for
    -- checking a signature].)
    --
    -- The resulting KindVar are the variables to quantify over, in the
    -- correct, well-scoped order. They should generally be Inferred, not
    -- Specified, but that's really up to the caller of this function.
    kindGeneralizeSome :: WantedConstraints
                       -> TcType    -- ^ needn't be zonked
                       -> TcM [KindVar]
    kindGeneralizeSome :: WantedConstraints -> Type -> TcM [TyVar]
    kindGeneralizeSome WantedConstraints
    wanted Type
    kind_or_type
      = do { -- Use the "Kind" variant here, as any types we see
             -- here will already have all type variables quantified;
             -- thus, every free variable is really a kv, never a tv.
           ; CandidatesQTvs
    dvs <- Type -> TcM CandidatesQTvs
    candidateQTyVarsOfKind Type
    kind_or_type
           ; CandidatesQTvs
    dvs <- WantedConstraints -> CandidatesQTvs -> TcM CandidatesQTvs
    filterConstrainedCandidates WantedConstraints
    wanted CandidatesQTvs
    dvs
           ; CandidatesQTvs -> TcM [TyVar]
    quantifyTyVars CandidatesQTvs
    dvs }

    filterConstrainedCandidates
      :: WantedConstraints    -- Don't quantify over variables free in these
                              --   Not necessarily fully zonked
      -> CandidatesQTvs       -- Candidates for quantification
      -> TcM CandidatesQTvs
    -- filterConstrainedCandidates removes any candidates that are free in
    -- 'wanted'; instead, it promotes them.  This bit is very much like
    -- decideMonoTyVars in GHC.Tc.Solver, but constraints are so much
    -- simpler in kinds, it is much easier here. (In particular, we never
    -- quantify over a constraint in a type.)
    filterConstrainedCandidates :: WantedConstraints -> CandidatesQTvs -> TcM CandidatesQTvs
    filterConstrainedCandidates WantedConstraints
    wanted CandidatesQTvs
    dvs
      | WantedConstraints -> Bool
    isEmptyWC WantedConstraints
    wanted   -- Fast path for a common case
      = CandidatesQTvs -> TcM CandidatesQTvs
    forall (m :: * -> *) a. Monad m => a -> m a
    return CandidatesQTvs
    dvs
      | Bool
    otherwise
      = do { VarSet
    wc_tvs <- VarSet -> TcM VarSet
    zonkTyCoVarsAndFV (WantedConstraints -> VarSet
    tyCoVarsOfWC WantedConstraints
    wanted)
           ; let (VarSet
    to_promote, CandidatesQTvs
    dvs') = CandidatesQTvs -> (TyVar -> Bool) -> (VarSet, CandidatesQTvs)
    partitionCandidates CandidatesQTvs
    dvs (TyVar -> VarSet -> Bool
    `elemVarSet` VarSet
    wc_tvs)
           ; Bool
    _ <- VarSet -> TcRnIf TcGblEnv TcLclEnv Bool
    promoteTyVarSet VarSet
    to_promote
           ; CandidatesQTvs -> TcM CandidatesQTvs
    forall (m :: * -> *) a. Monad m => a -> m a
    return CandidatesQTvs
    dvs' }

    -- |- Specialised version of 'kindGeneralizeSome', but with empty
    -- WantedConstraints, so no filtering is needed
    -- i.e.   kindGeneraliseAll = kindGeneralizeSome emptyWC
    kindGeneralizeAll :: TcType -> TcM [KindVar]
    kindGeneralizeAll :: Type -> TcM [TyVar]
    kindGeneralizeAll Type
    kind_or_type
      = do { String -> SDoc -> TcM ()
    traceTc String
    "kindGeneralizeAll" (Type -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr Type
    kind_or_type)
           ; CandidatesQTvs
    dvs <- Type -> TcM CandidatesQTvs
    candidateQTyVarsOfKind Type
    kind_or_type
           ; CandidatesQTvs -> TcM [TyVar]
    quantifyTyVars CandidatesQTvs
    dvs }

    -- | Specialized version of 'kindGeneralizeSome', but where no variables
    -- can be generalized, but perhaps some may need to be promoted.
    -- Use this variant when it is unknowable whether metavariables might
    -- later be constrained.
    --
    -- To see why this promotion is needed, see
    -- Note [Recipe for checking a signature], and especially
    -- Note [Promotion in signatures].
    kindGeneralizeNone :: TcType  -- needn't be zonked
                       -> TcM ()
    kindGeneralizeNone :: Type -> TcM ()
    kindGeneralizeNone Type
    kind_or_type
      = do { String -> SDoc -> TcM ()
    traceTc String
    "kindGeneralizeNone" (Type -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr Type
    kind_or_type)
           ; CandidatesQTvs
    dvs <- Type -> TcM CandidatesQTvs
    candidateQTyVarsOfKind Type
    kind_or_type
           ; Bool
    _ <- VarSet -> TcRnIf TcGblEnv TcLclEnv Bool
    promoteTyVarSet (CandidatesQTvs -> VarSet
    candidateKindVars CandidatesQTvs
    dvs)
           ; () -> TcM ()
    forall (m :: * -> *) a. Monad m => a -> m a
    return () }

    {- Note [Levels and generalisation]
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    Consider
      f x = e
    with no type signature. We are currently at level i.
    We must
      * Push the level to level (i+1)
      * Allocate a fresh alpha[i+1] for the result type
      * Check that e :: alpha[i+1], gathering constraint WC
      * Solve WC as far as possible
      * Zonking the result type alpha[i+1], say to beta[i-1] -> gamma[i]
      * Find the free variables with level > i, in this case gamma[i]
      * Skolemise those free variables and quantify over them, giving
           f :: forall g. beta[i-1] -> g
      * Emit the residiual constraint wrapped in an implication for g,
        thus   forall g. WC

    All of this happens for types too.  Consider
      f :: Int -> (forall a. Proxy a -> Int)

    Note [Kind generalisation]
    ~~~~~~~~~~~~~~~~~~~~~~~~~~
    We do kind generalisation only at the outer level of a type signature.
    For example, consider
      T :: forall k. k -> *
      f :: (forall a. T a -> Int) -> Int
    When kind-checking f's type signature we generalise the kind at
    the outermost level, thus:
      f1 :: forall k. (forall (a:k). T k a -> Int) -> Int  -- YES!
    and *not* at the inner forall:
      f2 :: (forall k. forall (a:k). T k a -> Int) -> Int  -- NO!
    Reason: same as for HM inference on value level declarations,
    we want to infer the most general type.  The f2 type signature
    would be *less applicable* than f1, because it requires a more
    polymorphic argument.

    NB: There are no explicit kind variables written in f's signature.
    When there are, the renamer adds these kind variables to the list of
    variables bound by the forall, so you can indeed have a type that's
    higher-rank in its kind. But only by explicit request.

    Note [Kinds of quantified type variables]
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    tcTyVarBndrsGen quantifies over a specified list of type variables,
    *and* over the kind variables mentioned in the kinds of those tyvars.

    Note that we must zonk those kinds (obviously) but less obviously, we
    must return type variables whose kinds are zonked too. Example
        (a :: k7)  where  k7 := k9 -> k9
    We must return
        [k9, a:k9->k9]
    and NOT
        [k9, a:k7]
    Reason: we're going to turn this into a for-all type,
       forall k9. forall (a:k7). blah
    which the type checker will then instantiate, and instantiate does not
    look through unification variables!

    Hence using zonked_kinds when forming tvs'.

    -}

    -----------------------------------
    etaExpandAlgTyCon :: [TyConBinder]
                      -> Kind   -- must be zonked
                      -> TcM ([TyConBinder], Kind)
    -- GADT decls can have a (perhaps partial) kind signature
    --      e.g.  data T a :: * -> * -> * where ...
    -- This function makes up suitable (kinded) TyConBinders for the
    -- argument kinds.  E.g. in this case it might return
    --   ([b::*, c::*], *)
    -- Never emits constraints.
    -- It's a little trickier than you might think: see
    -- Note [TyConBinders for the result kind signature of a data type]
    -- See Note [Datatype return kinds] in GHC.Tc.TyCl
    etaExpandAlgTyCon :: [TyConBinder] -> Type -> TcM ([TyConBinder], Type)
    etaExpandAlgTyCon [TyConBinder]
    tc_bndrs Type
    kind
      = do  { SrcSpan
    loc     <- TcRn SrcSpan
    getSrcSpanM
            ; UniqSupply
    uniqs   <- TcRnIf TcGblEnv TcLclEnv UniqSupply
    forall gbl lcl. TcRnIf gbl lcl UniqSupply
    newUniqueSupply
            ; LocalRdrEnv
    rdr_env <- RnM LocalRdrEnv
    getLocalRdrEnv
            ; let new_occs :: [OccName]
    new_occs = [ OccName
    occ
                             | String
    str <- [String]
    allNameStrings
                             , let occ :: OccName
    occ = NameSpace -> String -> OccName
    mkOccName NameSpace
    tvName String
    str
                             , Maybe Name -> Bool
    forall a. Maybe a -> Bool
    isNothing (LocalRdrEnv -> OccName -> Maybe Name
    lookupLocalRdrOcc LocalRdrEnv
    rdr_env OccName
    occ)
                             -- Note [Avoid name clashes for associated data types]
                             , Bool -> Bool
    not (OccName
    occ OccName -> [OccName] -> Bool
    forall (t :: * -> *) a. (Foldable t, Eq a) => a -> t a -> Bool
    `elem` [OccName]
    lhs_occs) ]
                  new_uniqs :: [Unique]
    new_uniqs = UniqSupply -> [Unique]
    uniqsFromSupply UniqSupply
    uniqs
                  subst :: TCvSubst
    subst = InScopeSet -> TCvSubst
    mkEmptyTCvSubst (VarSet -> InScopeSet
    mkInScopeSet ([TyVar] -> VarSet
    mkVarSet [TyVar]
    lhs_tvs))
            ; ([TyConBinder], Type) -> TcM ([TyConBinder], Type)
    forall (m :: * -> *) a. Monad m => a -> m a
    return (SrcSpan
    -> [OccName]
    -> [Unique]
    -> TCvSubst
    -> [TyConBinder]
    -> Type
    -> ([TyConBinder], Type)
    go SrcSpan
    loc [OccName]
    new_occs [Unique]
    new_uniqs TCvSubst
    subst [] Type
    kind) }
      where
        lhs_tvs :: [TyVar]
    lhs_tvs  = (TyConBinder -> TyVar) -> [TyConBinder] -> [TyVar]
    forall a b. (a -> b) -> [a] -> [b]
    map TyConBinder -> TyVar
    forall tv argf. VarBndr tv argf -> tv
    binderVar [TyConBinder]
    tc_bndrs
        lhs_occs :: [OccName]
    lhs_occs = (TyVar -> OccName) -> [TyVar] -> [OccName]
    forall a b. (a -> b) -> [a] -> [b]
    map TyVar -> OccName
    forall a. NamedThing a => a -> OccName
    getOccName [TyVar]
    lhs_tvs

        go :: SrcSpan
    -> [OccName]
    -> [Unique]
    -> TCvSubst
    -> [TyConBinder]
    -> Type
    -> ([TyConBinder], Type)
    go SrcSpan
    loc [OccName]
    occs [Unique]
    uniqs TCvSubst
    subst [TyConBinder]
    acc Type
    kind
          = case Type -> Maybe (TyBinder, Type)
    splitPiTy_maybe Type
    kind of
              Maybe (TyBinder, Type)
    Nothing -> ([TyConBinder] -> [TyConBinder]
    forall a. [a] -> [a]
    reverse [TyConBinder]
    acc, HasCallStack => TCvSubst -> Type -> Type
    TCvSubst -> Type -> Type
    substTy TCvSubst
    subst Type
    kind)

              Just (Anon AnonArgFlag
    af Scaled Type
    arg, Type
    kind')
                -> SrcSpan
    -> [OccName]
    -> [Unique]
    -> TCvSubst
    -> [TyConBinder]
    -> Type
    -> ([TyConBinder], Type)
    go SrcSpan
    loc [OccName]
    occs' [Unique]
    uniqs' TCvSubst
    subst' (TyConBinder
    tcb TyConBinder -> [TyConBinder] -> [TyConBinder]
    forall a. a -> [a] -> [a]
    : [TyConBinder]
    acc) Type
    kind'
                where
                  arg' :: Type
    arg'   = HasCallStack => TCvSubst -> Type -> Type
    TCvSubst -> Type -> Type
    substTy TCvSubst
    subst (Scaled Type -> Type
    forall a. Scaled a -> a
    scaledThing Scaled Type
    arg)
                  tv :: TyVar
    tv     = Name -> Type -> TyVar
    mkTyVar (Unique -> OccName -> SrcSpan -> Name
    mkInternalName Unique
    uniq OccName
    occ SrcSpan
    loc) Type
    arg'
                  subst' :: TCvSubst
    subst' = TCvSubst -> TyVar -> TCvSubst
    extendTCvInScope TCvSubst
    subst TyVar
    tv
                  tcb :: TyConBinder
    tcb    = TyVar -> TyConBndrVis -> TyConBinder
    forall var argf. var -> argf -> VarBndr var argf
    Bndr TyVar
    tv (AnonArgFlag -> TyConBndrVis
    AnonTCB AnonArgFlag
    af)
                  (Unique
    uniq:[Unique]
    uniqs') = [Unique]
    uniqs
                  (OccName
    occ:[OccName]
    occs')   = [OccName]
    occs

              Just (Named (Bndr TyVar
    tv ArgFlag
    vis), Type
    kind')
                -> SrcSpan
    -> [OccName]
    -> [Unique]
    -> TCvSubst
    -> [TyConBinder]
    -> Type
    -> ([TyConBinder], Type)
    go SrcSpan
    loc [OccName]
    occs [Unique]
    uniqs TCvSubst
    subst' (TyConBinder
    tcb TyConBinder -> [TyConBinder] -> [TyConBinder]
    forall a. a -> [a] -> [a]
    : [TyConBinder]
    acc) Type
    kind'
                where
                  (TCvSubst
    subst', TyVar
    tv') = HasCallStack => TCvSubst -> TyVar -> (TCvSubst, TyVar)
    TCvSubst -> TyVar -> (TCvSubst, TyVar)
    substTyVarBndr TCvSubst
    subst TyVar
    tv
                  tcb :: TyConBinder
    tcb = TyVar -> TyConBndrVis -> TyConBinder
    forall var argf. var -> argf -> VarBndr var argf
    Bndr TyVar
    tv' (ArgFlag -> TyConBndrVis
    NamedTCB ArgFlag
    vis)

    -- | A description of whether something is a
    --
    -- * @data@ or @newtype@ ('DataDeclSort')
    --
    -- * @data instance@ or @newtype instance@ ('DataInstanceSort')
    --
    -- * @data family@ ('DataFamilySort')
    --
    -- At present, this data type is only consumed by 'checkDataKindSig'.
    data DataSort
      = DataDeclSort     NewOrData
      | DataInstanceSort NewOrData
      | DataFamilySort

    -- | Local helper type used in 'checkDataKindSig'.
    --
    -- Superficially similar to 'ContextKind', but it lacks 'AnyKind'
    -- and 'AnyBoxedKind', and instead of @'TheKind' liftedTypeKind@
    -- provides 'LiftedKind', which is much simpler to match on and
    -- handle in 'isAllowedDataResKind'.
    data AllowedDataResKind
      = AnyTYPEKind
      | AnyBoxedKind
      | LiftedKind

    isAllowedDataResKind :: AllowedDataResKind -> Kind -> Bool
    isAllowedDataResKind :: AllowedDataResKind -> Type -> Bool
    isAllowedDataResKind AllowedDataResKind
    AnyTYPEKind  Type
    kind = Type -> Bool
    tcIsRuntimeTypeKind Type
    kind
    isAllowedDataResKind AllowedDataResKind
    AnyBoxedKind Type
    kind = Type -> Bool
    tcIsBoxedTypeKind Type
    kind
    isAllowedDataResKind AllowedDataResKind
    LiftedKind   Type
    kind = Type -> Bool
    tcIsLiftedTypeKind Type
    kind

    -- | Checks that the return kind in a data declaration's kind signature is
    -- permissible. There are three cases:
    --
    -- If dealing with a @data@, @newtype@, @data instance@, or @newtype instance@
    -- declaration, check that the return kind is @Type@.
    --
    -- If the declaration is a @newtype@ or @newtype instance@ and the
    -- @UnliftedNewtypes@ extension is enabled, this check is slightly relaxed so
    -- that a return kind of the form @TYPE r@ (for some @r@) is permitted.
    -- See @Note [Implementation of UnliftedNewtypes]@ in "GHC.Tc.TyCl".
    --
    -- If dealing with a @data family@ declaration, check that the return kind is
    -- either of the form:
    --
    -- 1. @TYPE r@ (for some @r@), or
    --
    -- 2. @k@ (where @k@ is a bare kind variable; see #12369)
    --
    -- See also Note [Datatype return kinds] in "GHC.Tc.TyCl"
    checkDataKindSig :: DataSort -> Kind  -- any arguments in the kind are stripped off
                     -> TcM ()
    checkDataKindSig :: DataSort -> Type -> TcM ()
    checkDataKindSig DataSort
    data_sort Type
    kind
      = do { DynFlags
    dflags <- IOEnv (Env TcGblEnv TcLclEnv) DynFlags
    forall (m :: * -> *). HasDynFlags m => m DynFlags
    getDynFlags
           ; String -> SDoc -> TcM ()
    traceTc String
    "checkDataKindSig" (Type -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr Type
    kind)
           ; Bool -> SDoc -> TcM ()
    checkTc (DynFlags -> Bool
    tYPE_ok DynFlags
    dflags Bool -> Bool -> Bool
    || Bool
    is_kind_var)
                     (DynFlags -> SDoc
    err_msg DynFlags
    dflags) }
      where
        res_kind :: Type
    res_kind = ([TyBinder], Type) -> Type
    forall a b. (a, b) -> b
    snd (Type -> ([TyBinder], Type)
    tcSplitPiTys Type
    kind)
           -- Look for the result kind after
           -- peeling off any foralls and arrows

        pp_dec :: SDoc
        pp_dec :: SDoc
    pp_dec = String -> SDoc
    text (String -> SDoc) -> String -> SDoc
    forall a b. (a -> b) -> a -> b
    $
          case DataSort
    data_sort of
            DataDeclSort     NewOrData
    DataType -> String
    "Data type"
            DataDeclSort     NewOrData
    NewType  -> String
    "Newtype"
            DataInstanceSort NewOrData
    DataType -> String
    "Data instance"
            DataInstanceSort NewOrData
    NewType  -> String
    "Newtype instance"
            DataSort
    DataFamilySort            -> String
    "Data family"

        is_newtype :: Bool
        is_newtype :: Bool
    is_newtype =
          case DataSort
    data_sort of
            DataDeclSort     NewOrData
    new_or_data -> NewOrData
    new_or_data NewOrData -> NewOrData -> Bool
    forall a. Eq a => a -> a -> Bool
    == NewOrData
    NewType
            DataInstanceSort NewOrData
    new_or_data -> NewOrData
    new_or_data NewOrData -> NewOrData -> Bool
    forall a. Eq a => a -> a -> Bool
    == NewOrData
    NewType
            DataSort
    DataFamilySort               -> Bool
    False

        is_datatype :: Bool
        is_datatype :: Bool
    is_datatype =
          case DataSort
    data_sort of
            DataDeclSort     NewOrData
    DataType -> Bool
    True
            DataInstanceSort NewOrData
    DataType -> Bool
    True
            DataSort
    _                         -> Bool
    False

        is_data_family :: Bool
        is_data_family :: Bool
    is_data_family =
          case DataSort
    data_sort of
            DataDeclSort{}     -> Bool
    False
            DataInstanceSort{} -> Bool
    False
            DataSort
    DataFamilySort     -> Bool
    True

        allowed_kind :: DynFlags -> AllowedDataResKind
        allowed_kind :: DynFlags -> AllowedDataResKind
    allowed_kind DynFlags
    dflags
          | Bool
    is_newtype Bool -> Bool -> Bool
    && Extension -> DynFlags -> Bool
    xopt Extension
    LangExt.UnliftedNewtypes DynFlags
    dflags
            -- With UnliftedNewtypes, we allow kinds other than Type, but they
            -- must still be of the form `TYPE r` since we don't want to accept
            -- Constraint or Nat.
            -- See Note [Implementation of UnliftedNewtypes] in GHC.Tc.TyCl.
          = AllowedDataResKind
    AnyTYPEKind
          | Bool
    is_data_family
            -- If this is a `data family` declaration, we don't need to check if
            -- UnliftedNewtypes is enabled, since data family declarations can
            -- have return kind `TYPE r` unconditionally (#16827).
          = AllowedDataResKind
    AnyTYPEKind
          | Bool
    is_datatype Bool -> Bool -> Bool
    && Extension -> DynFlags -> Bool
    xopt Extension
    LangExt.UnliftedDatatypes DynFlags
    dflags
            -- With UnliftedDatatypes, we allow kinds other than Type, but they
            -- must still be of the form `TYPE (BoxedRep l)`, so that we don't
            -- accept result kinds like `TYPE IntRep`.
            -- See Note [Implementation of UnliftedDatatypes] in GHC.Tc.TyCl.
          = AllowedDataResKind
    AnyBoxedKind
          | Bool
    otherwise
          = AllowedDataResKind
    LiftedKind

        tYPE_ok :: DynFlags -> Bool
        tYPE_ok :: DynFlags -> Bool
    tYPE_ok DynFlags
    dflags = AllowedDataResKind -> Type -> Bool
    isAllowedDataResKind (DynFlags -> AllowedDataResKind
    allowed_kind DynFlags
    dflags) Type
    res_kind

        -- In the particular case of a data family, permit a return kind of the
        -- form `:: k` (where `k` is a bare kind variable).
        is_kind_var :: Bool
        is_kind_var :: Bool
    is_kind_var | Bool
    is_data_family = Maybe (TyVar, Coercion) -> Bool
    forall a. Maybe a -> Bool
    isJust (Type -> Maybe (TyVar, Coercion)
    tcGetCastedTyVar_maybe Type
    res_kind)
                    | Bool
    otherwise      = Bool
    False

        pp_allowed_kind :: DynFlags -> SDoc
    pp_allowed_kind DynFlags
    dflags =
          case DynFlags -> AllowedDataResKind
    allowed_kind DynFlags
    dflags of
            AllowedDataResKind
    AnyTYPEKind  -> TyCon -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr TyCon
    tYPETyCon
            AllowedDataResKind
    AnyBoxedKind -> TyCon -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr TyCon
    boxedRepDataConTyCon
            AllowedDataResKind
    LiftedKind   -> Type -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr Type
    liftedTypeKind

        err_msg :: DynFlags -> SDoc
        err_msg :: DynFlags -> SDoc
    err_msg DynFlags
    dflags =
          [SDoc] -> SDoc
    sep [ [SDoc] -> SDoc
    sep [ SDoc
    pp_dec SDoc -> SDoc -> SDoc
    <+>
                      String -> SDoc
    text String
    "has non-" SDoc -> SDoc -> SDoc
    <>
                      DynFlags -> SDoc
    pp_allowed_kind DynFlags
    dflags
                    , (if Bool
    is_data_family then String -> SDoc
    text String
    "and non-variable" else SDoc
    empty) SDoc -> SDoc -> SDoc
    <+>
                      String -> SDoc
    text String
    "return kind" SDoc -> SDoc -> SDoc
    <+> SDoc -> SDoc
    quotes (Type -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr Type
    kind) ]
              , DynFlags -> SDoc
    ext_hint DynFlags
    dflags ]

        ext_hint :: DynFlags -> SDoc
    ext_hint DynFlags
    dflags
          | Type -> Bool
    tcIsRuntimeTypeKind Type
    kind
          , Bool
    is_newtype
          , Bool -> Bool
    not (Extension -> DynFlags -> Bool
    xopt Extension
    LangExt.UnliftedNewtypes DynFlags
    dflags)
          = String -> SDoc
    text String
    "Perhaps you intended to use UnliftedNewtypes"
          | Type -> Bool
    tcIsBoxedTypeKind Type
    kind
          , Bool
    is_datatype
          , Bool -> Bool
    not (Extension -> DynFlags -> Bool
    xopt Extension
    LangExt.UnliftedDatatypes DynFlags
    dflags)
          = String -> SDoc
    text String
    "Perhaps you intended to use UnliftedDatatypes"
          | Bool
    otherwise
          = SDoc
    empty

    -- | Checks that the result kind of a class is exactly `Constraint`, rejecting
    -- type synonyms and type families that reduce to `Constraint`. See #16826.
    checkClassKindSig :: Kind -> TcM ()
    checkClassKindSig :: Type -> TcM ()
    checkClassKindSig Type
    kind = Bool -> SDoc -> TcM ()
    checkTc (Type -> Bool
    tcIsConstraintKind Type
    kind) SDoc
    err_msg
      where
        err_msg :: SDoc
        err_msg :: SDoc
    err_msg =
          String -> SDoc
    text String
    "Kind signature on a class must end with" SDoc -> SDoc -> SDoc
    <+> Type -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr Type
    constraintKind SDoc -> SDoc -> SDoc
    $$
          String -> SDoc
    text String
    "unobscured by type families"

    tcbVisibilities :: TyCon -> [Type] -> [TyConBndrVis]
    -- Result is in 1-1 correspondence with orig_args
    tcbVisibilities :: TyCon -> [Type] -> [TyConBndrVis]
    tcbVisibilities TyCon
    tc [Type]
    orig_args
      = Type -> TCvSubst -> [Type] -> [TyConBndrVis]
    go (TyCon -> Type
    tyConKind TyCon
    tc) TCvSubst
    init_subst [Type]
    orig_args
      where
        init_subst :: TCvSubst
    init_subst = InScopeSet -> TCvSubst
    mkEmptyTCvSubst (VarSet -> InScopeSet
    mkInScopeSet ([Type] -> VarSet
    tyCoVarsOfTypes [Type]
    orig_args))
        go :: Type -> TCvSubst -> [Type] -> [TyConBndrVis]
    go Type
    _ TCvSubst
    _ []
          = []

        go Type
    fun_kind TCvSubst
    subst all_args :: [Type]
    all_args@(Type
    arg : [Type]
    args)
          | Just (TyBinder
    tcb, Type
    inner_kind) <- Type -> Maybe (TyBinder, Type)
    splitPiTy_maybe Type
    fun_kind
          = case TyBinder
    tcb of
              Anon AnonArgFlag
    af Scaled Type
    _           -> AnonArgFlag -> TyConBndrVis
    AnonTCB AnonArgFlag
    af   TyConBndrVis -> [TyConBndrVis] -> [TyConBndrVis]
    forall a. a -> [a] -> [a]
    : Type -> TCvSubst -> [Type] -> [TyConBndrVis]
    go Type
    inner_kind TCvSubst
    subst  [Type]
    args
              Named (Bndr TyVar
    tv ArgFlag
    vis) -> ArgFlag -> TyConBndrVis
    NamedTCB ArgFlag
    vis TyConBndrVis -> [TyConBndrVis] -> [TyConBndrVis]
    forall a. a -> [a] -> [a]
    : Type -> TCvSubst -> [Type] -> [TyConBndrVis]
    go Type
    inner_kind TCvSubst
    subst' [Type]
    args
                     where
                        subst' :: TCvSubst
    subst' = TCvSubst -> TyVar -> Type -> TCvSubst
    extendTCvSubst TCvSubst
    subst TyVar
    tv Type
    arg

          | Bool -> Bool
    not (TCvSubst -> Bool
    isEmptyTCvSubst TCvSubst
    subst)
          = Type -> TCvSubst -> [Type] -> [TyConBndrVis]
    go (HasCallStack => TCvSubst -> Type -> Type
    TCvSubst -> Type -> Type
    substTy TCvSubst
    subst Type
    fun_kind) TCvSubst
    init_subst [Type]
    all_args

          | Bool
    otherwise
          = String -> SDoc -> [TyConBndrVis]
    forall a. HasCallStack => String -> SDoc -> a
    pprPanic String
    "addTcbVisibilities" (TyCon -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr TyCon
    tc SDoc -> SDoc -> SDoc
    <+> [Type] -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr [Type]
    orig_args)

    {- Note [TyConBinders for the result kind signature of a data type]
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    Given
      data T (a::*) :: * -> forall k. k -> *
    we want to generate the extra TyConBinders for T, so we finally get
      (a::*) (b::*) (k::*) (c::k)
    The function etaExpandAlgTyCon generates these extra TyConBinders from
    the result kind signature.

    We need to take care to give the TyConBinders
      (a) OccNames that are fresh (because the TyConBinders of a TyCon
          must have distinct OccNames

      (b) Uniques that are fresh (obviously)

    For (a) we need to avoid clashes with the tyvars declared by
    the user before the "::"; in the above example that is 'a'.
    And also see Note [Avoid name clashes for associated data types].

    For (b) suppose we have
       data T :: forall k. k -> forall k. k -> *
    where the two k's are identical even up to their uniques.  Surprisingly,
    this can happen: see #14515.

    It's reasonably easy to solve all this; just run down the list with a
    substitution; hence the recursive 'go' function.  But it has to be
    done.

    Note [Avoid name clashes for associated data types]
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    Consider    class C a b where
                   data D b :: * -> *
    When typechecking the decl for D, we'll invent an extra type variable
    for D, to fill out its kind.  Ideally we don't want this type variable
    to be 'a', because when pretty printing we'll get
                class C a b where
                   data D b a0
    (NB: the tidying happens in the conversion to Iface syntax, which happens
    as part of pretty-printing a TyThing.)

    That's why we look in the LocalRdrEnv to see what's in scope. This is
    important only to get nice-looking output when doing ":info C" in GHCi.
    It isn't essential for correctness.

    ************************************************************************
    *                                                                      *
                 Partial signatures
    *                                                                      *
    ************************************************************************

    -}

    tcHsPartialSigType
      :: UserTypeCtxt
      -> LHsSigWcType GhcRn       -- The type signature
      -> TcM ( [(Name, TcTyVar)]  -- Wildcards
             , Maybe TcType       -- Extra-constraints wildcard
             , [(Name,InvisTVBinder)] -- Original tyvar names, in correspondence with
                                  --   the implicitly and explicitly bound type variables
             , TcThetaType        -- Theta part
             , TcType )           -- Tau part
    -- See Note [Checking partial type signatures]
    tcHsPartialSigType :: UserTypeCtxt
    -> LHsSigWcType GhcRn
    -> TcM
         ([(Name, TyVar)], Maybe Type, [(Name, InvisTVBinder)], [Type],
          Type)
    tcHsPartialSigType UserTypeCtxt
    ctxt LHsSigWcType GhcRn
    sig_ty
      | HsWC { hswc_ext :: forall pass thing. HsWildCardBndrs pass thing -> XHsWC pass thing
    hswc_ext  = XHsWC GhcRn (LHsSigType GhcRn)
    sig_wcs, hswc_body :: forall pass thing. HsWildCardBndrs pass thing -> thing
    hswc_body = LHsSigType GhcRn
    sig_ty } <- LHsSigWcType GhcRn
    sig_ty
      , L SrcSpanAnnA
    _ (HsSig{sig_bndrs :: forall pass. HsSigType pass -> HsOuterSigTyVarBndrs pass
    sig_bndrs = HsOuterSigTyVarBndrs GhcRn
    hs_outer_bndrs, sig_body :: forall pass. HsSigType pass -> LHsType pass
    sig_body = LHsType GhcRn
    body_ty}) <- LHsSigType GhcRn
    sig_ty
      , (Maybe (LHsContext GhcRn)
    hs_ctxt, LHsType GhcRn
    hs_tau) <- LHsType GhcRn -> (Maybe (LHsContext GhcRn), LHsType GhcRn)
    forall (pass :: Pass).
    LHsType (GhcPass pass)
    -> (Maybe (LHsContext (GhcPass pass)), LHsType (GhcPass pass))
    splitLHsQualTy LHsType GhcRn
    body_ty
      = UserTypeCtxt
    -> GenLocated SrcSpanAnnA (HsSigType GhcRn)
    -> TcM
         ([(Name, TyVar)], Maybe Type, [(Name, InvisTVBinder)], [Type],
          Type)
    -> TcM
         ([(Name, TyVar)], Maybe Type, [(Name, InvisTVBinder)], [Type],
          Type)
    forall hs_ty a.
    Outputable hs_ty =>
    UserTypeCtxt -> LocatedA hs_ty -> TcM a -> TcM a
    addSigCtxt UserTypeCtxt
    ctxt GenLocated SrcSpanAnnA (HsSigType GhcRn)
    LHsSigType GhcRn
    sig_ty (TcM
       ([(Name, TyVar)], Maybe Type, [(Name, InvisTVBinder)], [Type],
        Type)
     -> TcM
          ([(Name, TyVar)], Maybe Type, [(Name, InvisTVBinder)], [Type],
           Type))
    -> TcM
         ([(Name, TyVar)], Maybe Type, [(Name, InvisTVBinder)], [Type],
          Type)
    -> TcM
         ([(Name, TyVar)], Maybe Type, [(Name, InvisTVBinder)], [Type],
          Type)
    forall a b. (a -> b) -> a -> b
    $
        do { TcTyMode
    mode <- TypeOrKind -> HoleMode -> TcM TcTyMode
    mkHoleMode TypeOrKind
    TypeLevel HoleMode
    HM_Sig
           ; (HsOuterTyVarBndrs Specificity GhcTc
    outer_bndrs, ([(Name, TyVar)]
    wcs, Maybe Type
    wcx, [Type]
    theta, Type
    tau))
                <- String
    -> TcM
         (HsOuterTyVarBndrs Specificity GhcTc,
          ([(Name, TyVar)], Maybe Type, [Type], Type))
    -> TcM
         (HsOuterTyVarBndrs Specificity GhcTc,
          ([(Name, TyVar)], Maybe Type, [Type], Type))
    forall a. String -> TcM a -> TcM a
    solveEqualities String
    "tcHsPartialSigType" (TcM
       (HsOuterTyVarBndrs Specificity GhcTc,
        ([(Name, TyVar)], Maybe Type, [Type], Type))
     -> TcM
          (HsOuterTyVarBndrs Specificity GhcTc,
           ([(Name, TyVar)], Maybe Type, [Type], Type)))
    -> TcM
         (HsOuterTyVarBndrs Specificity GhcTc,
          ([(Name, TyVar)], Maybe Type, [Type], Type))
    -> TcM
         (HsOuterTyVarBndrs Specificity GhcTc,
          ([(Name, TyVar)], Maybe Type, [Type], Type))
    forall a b. (a -> b) -> a -> b
    $
                   -- See Note [Failure in local type signatures]
                   HsQTvsRn
    -> ([(Name, TyVar)]
        -> TcM
             (HsOuterTyVarBndrs Specificity GhcTc,
              ([(Name, TyVar)], Maybe Type, [Type], Type)))
    -> TcM
         (HsOuterTyVarBndrs Specificity GhcTc,
          ([(Name, TyVar)], Maybe Type, [Type], Type))
    forall a. HsQTvsRn -> ([(Name, TyVar)] -> TcM a) -> TcM a
    bindNamedWildCardBinders HsQTvsRn
    XHsWC GhcRn (LHsSigType GhcRn)
    sig_wcs             (([(Name, TyVar)]
      -> TcM
           (HsOuterTyVarBndrs Specificity GhcTc,
            ([(Name, TyVar)], Maybe Type, [Type], Type)))
     -> TcM
          (HsOuterTyVarBndrs Specificity GhcTc,
           ([(Name, TyVar)], Maybe Type, [Type], Type)))
    -> ([(Name, TyVar)]
        -> TcM
             (HsOuterTyVarBndrs Specificity GhcTc,
              ([(Name, TyVar)], Maybe Type, [Type], Type)))
    -> TcM
         (HsOuterTyVarBndrs Specificity GhcTc,
          ([(Name, TyVar)], Maybe Type, [Type], Type))
    forall a b. (a -> b) -> a -> b
    $ \ [(Name, TyVar)]
    wcs ->
                   TcTyMode
    -> HsOuterSigTyVarBndrs GhcRn
    -> TcM ([(Name, TyVar)], Maybe Type, [Type], Type)
    -> TcM
         (HsOuterTyVarBndrs Specificity GhcTc,
          ([(Name, TyVar)], Maybe Type, [Type], Type))
    forall a.
    TcTyMode
    -> HsOuterSigTyVarBndrs GhcRn
    -> TcM a
    -> TcM (HsOuterTyVarBndrs Specificity GhcTc, a)
    bindOuterSigTKBndrs_Tv_M TcTyMode
    mode HsOuterSigTyVarBndrs GhcRn
    hs_outer_bndrs (TcM ([(Name, TyVar)], Maybe Type, [Type], Type)
     -> TcM
          (HsOuterTyVarBndrs Specificity GhcTc,
           ([(Name, TyVar)], Maybe Type, [Type], Type)))
    -> TcM ([(Name, TyVar)], Maybe Type, [Type], Type)
    -> TcM
         (HsOuterTyVarBndrs Specificity GhcTc,
          ([(Name, TyVar)], Maybe Type, [Type], Type))
    forall a b. (a -> b) -> a -> b
    $
                   do {   -- Instantiate the type-class context; but if there
                          -- is an extra-constraints wildcard, just discard it here
                        ([Type]
    theta, Maybe Type
    wcx) <- TcTyMode -> Maybe (LHsContext GhcRn) -> TcM ([Type], Maybe Type)
    tcPartialContext TcTyMode
    mode Maybe (LHsContext GhcRn)
    hs_ctxt

                      ; Type
    ek <- TcM Type
    newOpenTypeKind
                      ; Type
    tau <- LHsType GhcRn -> TcM Type -> TcM Type
    forall a. LHsType GhcRn -> TcM a -> TcM a
    addTypeCtxt LHsType GhcRn
    hs_tau (TcM Type -> TcM Type) -> TcM Type -> TcM Type
    forall a b. (a -> b) -> a -> b
    $
                               TcTyMode -> LHsType GhcRn -> Type -> TcM Type
    tc_lhs_type TcTyMode
    mode LHsType GhcRn
    hs_tau Type
    ek

                      ; ([(Name, TyVar)], Maybe Type, [Type], Type)
    -> TcM ([(Name, TyVar)], Maybe Type, [Type], Type)
    forall (m :: * -> *) a. Monad m => a -> m a
    return ([(Name, TyVar)]
    wcs, Maybe Type
    wcx, [Type]
    theta, Type
    tau) }

           ; String -> SDoc -> TcM ()
    traceTc String
    "tcHsPartialSigType 2" SDoc
    empty
           ; [InvisTVBinder]
    outer_tv_bndrs <- HsOuterTyVarBndrs Specificity GhcTc -> TcM [InvisTVBinder]
    scopedSortOuter HsOuterTyVarBndrs Specificity GhcTc
    outer_bndrs
           ; String -> SDoc -> TcM ()
    traceTc String
    "tcHsPartialSigType 3" SDoc
    empty

             -- No kind-generalization here:
           ; Type -> TcM ()
    kindGeneralizeNone ([InvisTVBinder] -> Type -> Type
    mkInvisForAllTys [InvisTVBinder]
    outer_tv_bndrs (Type -> Type) -> Type -> Type
    forall a b. (a -> b) -> a -> b
    $
                                 [Type] -> Type -> Type
    mkPhiTy [Type]
    theta (Type -> Type) -> Type -> Type
    forall a b. (a -> b) -> a -> b
    $
                                 Type
    tau)

           -- Spit out the wildcards (including the extra-constraints one)
           -- as "hole" constraints, so that they'll be reported if necessary
           -- See Note [Extra-constraint holes in partial type signatures]
           ; ((Name, TyVar) -> TcM ()) -> [(Name, TyVar)] -> TcM ()
    forall (t :: * -> *) (m :: * -> *) a b.
    (Foldable t, Monad m) =>
    (a -> m b) -> t a -> m ()
    mapM_ (Name, TyVar) -> TcM ()
    emitNamedTypeHole [(Name, TyVar)]
    wcs

           -- Zonk, so that any nested foralls can "see" their occurrences
           -- See Note [Checking partial type signatures], and in particular
           -- Note [Levels for wildcards]
           ; [InvisTVBinder]
    outer_tv_bndrs <- (InvisTVBinder -> IOEnv (Env TcGblEnv TcLclEnv) InvisTVBinder)
    -> [InvisTVBinder] -> TcM [InvisTVBinder]
    forall (t :: * -> *) (m :: * -> *) a b.
    (Traversable t, Monad m) =>
    (a -> m b) -> t a -> m (t b)
    mapM InvisTVBinder -> IOEnv (Env TcGblEnv TcLclEnv) InvisTVBinder
    forall spec. VarBndr TyVar spec -> TcM (VarBndr TyVar spec)
    zonkInvisTVBinder [InvisTVBinder]
    outer_tv_bndrs
           ; [Type]
    theta          <- (Type -> TcM Type) -> [Type] -> TcM [Type]
    forall (t :: * -> *) (m :: * -> *) a b.
    (Traversable t, Monad m) =>
    (a -> m b) -> t a -> m (t b)
    mapM Type -> TcM Type
    zonkTcType [Type]
    theta
           ; Type
    tau            <- Type -> TcM Type
    zonkTcType Type
    tau

             -- We return a proper (Name,InvisTVBinder) environment, to be sure that
             -- we bring the right name into scope in the function body.
             -- Test case: partial-sigs/should_compile/LocalDefinitionBug
           ; let outer_bndr_names :: [Name]
                 outer_bndr_names :: HsQTvsRn
    outer_bndr_names = HsOuterSigTyVarBndrs GhcRn -> HsQTvsRn
    forall flag. HsOuterTyVarBndrs flag GhcRn -> HsQTvsRn
    hsOuterTyVarNames HsOuterSigTyVarBndrs GhcRn
    hs_outer_bndrs
                 tv_prs :: [(Name,InvisTVBinder)]
                 tv_prs :: [(Name, InvisTVBinder)]
    tv_prs = HsQTvsRn
    outer_bndr_names HsQTvsRn -> [InvisTVBinder] -> [(Name, InvisTVBinder)]
    forall a b. [a] -> [b] -> [(a, b)]
    `zip` [InvisTVBinder]
    outer_tv_bndrs

          -- NB: checkValidType on the final inferred type will be
          --     done later by checkInferredPolyId.  We can't do it
          --     here because we don't have a complete type to check

           ; String -> SDoc -> TcM ()
    traceTc String
    "tcHsPartialSigType" ([(Name, InvisTVBinder)] -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr [(Name, InvisTVBinder)]
    tv_prs)
           ; ([(Name, TyVar)], Maybe Type, [(Name, InvisTVBinder)], [Type],
     Type)
    -> TcM
         ([(Name, TyVar)], Maybe Type, [(Name, InvisTVBinder)], [Type],
          Type)
    forall (m :: * -> *) a. Monad m => a -> m a
    return ([(Name, TyVar)]
    wcs, Maybe Type
    wcx, [(Name, InvisTVBinder)]
    tv_prs, [Type]
    theta, Type
    tau) }

    tcPartialContext :: TcTyMode -> Maybe (LHsContext GhcRn) -> TcM (TcThetaType, Maybe TcType)
    tcPartialContext :: TcTyMode -> Maybe (LHsContext GhcRn) -> TcM ([Type], Maybe Type)
    tcPartialContext TcTyMode
    _ Maybe (LHsContext GhcRn)
    Nothing = ([Type], Maybe Type) -> TcM ([Type], Maybe Type)
    forall (m :: * -> *) a. Monad m => a -> m a
    return ([], Maybe Type
    forall a. Maybe a
    Nothing)
    tcPartialContext TcTyMode
    mode (Just (L SrcSpanAnnC
    _ [GenLocated SrcSpanAnnA (HsType GhcRn)]
    hs_theta))
      | Just ([GenLocated SrcSpanAnnA (HsType GhcRn)]
    hs_theta1, GenLocated SrcSpanAnnA (HsType GhcRn)
    hs_ctxt_last) <- [GenLocated SrcSpanAnnA (HsType GhcRn)]
    -> Maybe
         ([GenLocated SrcSpanAnnA (HsType GhcRn)],
          GenLocated SrcSpanAnnA (HsType GhcRn))
    forall a. [a] -> Maybe ([a], a)
    snocView [GenLocated SrcSpanAnnA (HsType GhcRn)]
    hs_theta
      , L SrcSpanAnnA
    wc_loc ty :: HsType GhcRn
    ty@(HsWildCardTy XWildCardTy GhcRn
    _) <- LHsType GhcRn -> LHsType GhcRn
    forall (p :: Pass). LHsType (GhcPass p) -> LHsType (GhcPass p)
    ignoreParens GenLocated SrcSpanAnnA (HsType GhcRn)
    LHsType GhcRn
    hs_ctxt_last
      = do { Type
    wc_tv_ty <- SrcSpanAnnA -> TcM Type -> TcM Type
    forall ann a. SrcSpanAnn' ann -> TcRn a -> TcRn a
    setSrcSpanA SrcSpanAnnA
    wc_loc (TcM Type -> TcM Type) -> TcM Type -> TcM Type
    forall a b. (a -> b) -> a -> b
    $
                         IsExtraConstraint -> TcTyMode -> HsType GhcRn -> Type -> TcM Type
    tcAnonWildCardOcc IsExtraConstraint
    YesExtraConstraint TcTyMode
    mode HsType GhcRn
    ty Type
    constraintKind
           ; [Type]
    theta <- (GenLocated SrcSpanAnnA (HsType GhcRn) -> TcM Type)
    -> [GenLocated SrcSpanAnnA (HsType GhcRn)] -> TcM [Type]
    forall (t :: * -> *) (m :: * -> *) a b.
    (Traversable t, Monad m) =>
    (a -> m b) -> t a -> m (t b)
    mapM (TcTyMode -> LHsType GhcRn -> TcM Type
    tc_lhs_pred TcTyMode
    mode) [GenLocated SrcSpanAnnA (HsType GhcRn)]
    hs_theta1
           ; ([Type], Maybe Type) -> TcM ([Type], Maybe Type)
    forall (m :: * -> *) a. Monad m => a -> m a
    return ([Type]
    theta, Type -> Maybe Type
    forall a. a -> Maybe a
    Just Type
    wc_tv_ty) }
      | Bool
    otherwise
      = do { [Type]
    theta <- (GenLocated SrcSpanAnnA (HsType GhcRn) -> TcM Type)
    -> [GenLocated SrcSpanAnnA (HsType GhcRn)] -> TcM [Type]
    forall (t :: * -> *) (m :: * -> *) a b.
    (Traversable t, Monad m) =>
    (a -> m b) -> t a -> m (t b)
    mapM (TcTyMode -> LHsType GhcRn -> TcM Type
    tc_lhs_pred TcTyMode
    mode) [GenLocated SrcSpanAnnA (HsType GhcRn)]
    hs_theta
           ; ([Type], Maybe Type) -> TcM ([Type], Maybe Type)
    forall (m :: * -> *) a. Monad m => a -> m a
    return ([Type]
    theta, Maybe Type
    forall a. Maybe a
    Nothing) }

    {- Note [Checking partial type signatures]
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    This Note is about tcHsPartialSigType.  See also
    Note [Recipe for checking a signature]

    When we have a partial signature like
       f :: forall a. a -> _
    we do the following

    * tcHsPartialSigType does not make quantified type (forall a. blah)
      and then instantiate it -- it makes no sense to instantiate a type
      with wildcards in it.  Rather, tcHsPartialSigType just returns the
      'a' and the 'blah' separately.

      Nor, for the same reason, do we push a level in tcHsPartialSigType.

    * We instantiate 'a' to a unification variable, a TyVarTv, and /not/
      a skolem; hence the "_Tv" in bindExplicitTKBndrs_Tv.  Consider
        f :: forall a. a -> _
        g :: forall b. _ -> b
        f = g
        g = f
      They are typechecked as a recursive group, with monomorphic types,
      so 'a' and 'b' will get unified together.  Very like kind inference
      for mutually recursive data types (sans CUSKs or SAKS); see
      Note [Cloning for type variable binders]

    * In GHC.Tc.Gen.Sig.tcUserSigType we return a PartialSig, which (unlike
      the companion CompleteSig) contains the original, as-yet-unchecked
      source-code LHsSigWcType

    * Then, for f and g /separately/, we call tcInstSig, which in turn
      call tchsPartialSig (defined near this Note).  It kind-checks the
      LHsSigWcType, creating fresh unification variables for each "_"
      wildcard.  It's important that the wildcards for f and g are distinct
      because they might get instantiated completely differently.  E.g.
         f,g :: forall a. a -> _
         f x = a
         g x = True
      It's really as if we'd written two distinct signatures.

    * Nested foralls. See Note [Levels for wildcards]

    * Just as for ordinary signatures, we must solve local equalities and
      zonk the type after kind-checking it, to ensure that all the nested
      forall binders can "see" their occurrenceds

      Just as for ordinary signatures, this zonk also gets any Refl casts
      out of the way of instantiation.  Example: #18008 had
           foo :: (forall a. (Show a => blah) |> Refl) -> _
      and that Refl cast messed things up.  See #18062.

    Note [Levels for wildcards]
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~
    Consider
         f :: forall b. (forall a. a -> _) -> b
    We do /not/ allow the "_" to be instantiated to 'a'; although we do
    (as before) allow it to be instantiated to the (top level) 'b'.
    Why not?  Suppose
       f x = (x True, x 'c')

    During typecking the RHS we must instantiate that (forall a. a -> _),
    so we must know /precisely/ where all the a's are; they must not be
    hidden under (possibly-not-yet-filled-in) unification variables!

    We achieve this as follows:

    - For /named/ wildcards such sas
         g :: forall b. (forall la. a -> _x) -> b
      there is no problem: we create them at the outer level (ie the
      ambient level of the signature itself), and push the level when we
      go inside a forall.  So now the unification variable for the "_x"
      can't unify with skolem 'a'.

    - For /anonymous/ wildcards, such as 'f' above, we carry the ambient
      level of the signature to the hole in the TcLevel part of the
      mode_holes field of TcTyMode.  Then, in tcAnonWildCardOcc we us that
      level (and /not/ the level ambient at the occurrence of "_") to
      create the unification variable for the wildcard.  That is the sole
      purpose of the TcLevel in the mode_holes field: to transport the
      ambient level of the signature down to the anonymous wildcard
      occurrences.

    Note [Extra-constraint holes in partial type signatures]
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    Consider
      f :: (_) => a -> a
      f x = ...

    * The renamer leaves '_' untouched.

    * Then, in tcHsPartialSigType, we make a new hole TcTyVar, in
      tcWildCardBinders.

    * GHC.Tc.Gen.Bind.chooseInferredQuantifiers fills in that hole TcTyVar
      with the inferred constraints, e.g. (Eq a, Show a)

    * GHC.Tc.Errors.mkHoleError finally reports the error.

    An annoying difficulty happens if there are more than 64 inferred
    constraints. Then we need to fill in the TcTyVar with (say) a 70-tuple.
    Where do we find the TyCon?  For good reasons we only have constraint
    tuples up to 62 (see Note [How tuples work] in GHC.Builtin.Types).  So how
    can we make a 70-tuple?  This was the root cause of #14217.

    It's incredibly tiresome, because we only need this type to fill
    in the hole, to communicate to the error reporting machinery.  Nothing
    more.  So I use a HACK:

    * I make an /ordinary/ tuple of the constraints, in
      GHC.Tc.Gen.Bind.chooseInferredQuantifiers. This is ill-kinded because
      ordinary tuples can't contain constraints, but it works fine. And for
      ordinary tuples we don't have the same limit as for constraint
      tuples (which need selectors and an associated class).

    * Because it is ill-kinded, it trips an assert in writeMetaTyVar,
      so now I disable the assertion if we are writing a type of
      kind Constraint.  (That seldom/never normally happens so we aren't
      losing much.)

    Result works fine, but it may eventually bite us.

    See also Note [Do not simplify ConstraintHoles] in GHC.Tc.Solver for
    information about how these are printed.

    ************************************************************************
    *                                                                      *
          Pattern signatures (i.e signatures that occur in patterns)
    *                                                                      *
    ********************************************************************* -}

    tcHsPatSigType :: UserTypeCtxt
                   -> HoleMode -- HM_Sig when in a SigPat, HM_TyAppPat when in a ConPat checking type applications.
                   -> HsPatSigType GhcRn          -- The type signature
                   -> ContextKind                -- What kind is expected
                   -> TcM ( [(Name, TcTyVar)]     -- Wildcards
                          , [(Name, TcTyVar)]     -- The new bit of type environment, binding
                                                  -- the scoped type variables
                          , TcType)       -- The type
    -- Used for type-checking type signatures in
    -- (a) patterns           e.g  f (x::Int) = e
    -- (b) RULE forall bndrs  e.g. forall (x::Int). f x = x
    -- See Note [Pattern signature binders and scoping] in GHC.Hs.Type
    --
    -- This may emit constraints
    -- See Note [Recipe for checking a signature]
    tcHsPatSigType :: UserTypeCtxt
    -> HoleMode
    -> HsPatSigType GhcRn
    -> ContextKind
    -> TcM ([(Name, TyVar)], [(Name, TyVar)], Type)
    tcHsPatSigType UserTypeCtxt
    ctxt HoleMode
    hole_mode
      (HsPS { hsps_ext :: forall pass. HsPatSigType pass -> XHsPS pass
    hsps_ext  = HsPSRn { hsps_nwcs :: HsPSRn -> HsQTvsRn
    hsps_nwcs = HsQTvsRn
    sig_wcs, hsps_imp_tvs :: HsPSRn -> HsQTvsRn
    hsps_imp_tvs = HsQTvsRn
    sig_ns }
            , hsps_body :: forall pass. HsPatSigType pass -> LHsType pass
    hsps_body = LHsType GhcRn
    hs_ty })
      ContextKind
    ctxt_kind
      = UserTypeCtxt
    -> GenLocated SrcSpanAnnA (HsType GhcRn)
    -> TcM ([(Name, TyVar)], [(Name, TyVar)], Type)
    -> TcM ([(Name, TyVar)], [(Name, TyVar)], Type)
    forall hs_ty a.
    Outputable hs_ty =>
    UserTypeCtxt -> LocatedA hs_ty -> TcM a -> TcM a
    addSigCtxt UserTypeCtxt
    ctxt GenLocated SrcSpanAnnA (HsType GhcRn)
    LHsType GhcRn
    hs_ty (TcM ([(Name, TyVar)], [(Name, TyVar)], Type)
     -> TcM ([(Name, TyVar)], [(Name, TyVar)], Type))
    -> TcM ([(Name, TyVar)], [(Name, TyVar)], Type)
    -> TcM ([(Name, TyVar)], [(Name, TyVar)], Type)
    forall a b. (a -> b) -> a -> b
    $
        do { [(Name, TyVar)]
    sig_tkv_prs <- (Name -> IOEnv (Env TcGblEnv TcLclEnv) (Name, TyVar))
    -> HsQTvsRn -> IOEnv (Env TcGblEnv TcLclEnv) [(Name, TyVar)]
    forall (t :: * -> *) (m :: * -> *) a b.
    (Traversable t, Monad m) =>
    (a -> m b) -> t a -> m (t b)
    mapM Name -> IOEnv (Env TcGblEnv TcLclEnv) (Name, TyVar)
    new_implicit_tv HsQTvsRn
    sig_ns
           ; TcTyMode
    mode <- TypeOrKind -> HoleMode -> TcM TcTyMode
    mkHoleMode TypeOrKind
    TypeLevel HoleMode
    hole_mode
           ; ([(Name, TyVar)]
    wcs, Type
    sig_ty)
                <- LHsType GhcRn
    -> TcM ([(Name, TyVar)], Type) -> TcM ([(Name, TyVar)], Type)
    forall a. LHsType GhcRn -> TcM a -> TcM a
    addTypeCtxt LHsType GhcRn
    hs_ty                     (TcM ([(Name, TyVar)], Type) -> TcM ([(Name, TyVar)], Type))
    -> TcM ([(Name, TyVar)], Type) -> TcM ([(Name, TyVar)], Type)
    forall a b. (a -> b) -> a -> b
    $
                   String
    -> TcM ([(Name, TyVar)], Type) -> TcM ([(Name, TyVar)], Type)
    forall a. String -> TcM a -> TcM a
    solveEqualities String
    "tcHsPatSigType" (TcM ([(Name, TyVar)], Type) -> TcM ([(Name, TyVar)], Type))
    -> TcM ([(Name, TyVar)], Type) -> TcM ([(Name, TyVar)], Type)
    forall a b. (a -> b) -> a -> b
    $
                     -- See Note [Failure in local type signatures]
                     -- and c.f #16033
                   HsQTvsRn
    -> ([(Name, TyVar)] -> TcM ([(Name, TyVar)], Type))
    -> TcM ([(Name, TyVar)], Type)
    forall a. HsQTvsRn -> ([(Name, TyVar)] -> TcM a) -> TcM a
    bindNamedWildCardBinders HsQTvsRn
    sig_wcs (([(Name, TyVar)] -> TcM ([(Name, TyVar)], Type))
     -> TcM ([(Name, TyVar)], Type))
    -> ([(Name, TyVar)] -> TcM ([(Name, TyVar)], Type))
    -> TcM ([(Name, TyVar)], Type)
    forall a b. (a -> b) -> a -> b
    $ \ [(Name, TyVar)]
    wcs ->
                   [(Name, TyVar)]
    -> TcM ([(Name, TyVar)], Type) -> TcM ([(Name, TyVar)], Type)
    forall r. [(Name, TyVar)] -> TcM r -> TcM r
    tcExtendNameTyVarEnv [(Name, TyVar)]
    sig_tkv_prs (TcM ([(Name, TyVar)], Type) -> TcM ([(Name, TyVar)], Type))
    -> TcM ([(Name, TyVar)], Type) -> TcM ([(Name, TyVar)], Type)
    forall a b. (a -> b) -> a -> b
    $
                   do { Type
    ek     <- ContextKind -> TcM Type
    newExpectedKind ContextKind
    ctxt_kind
                      ; Type
    sig_ty <- TcTyMode -> LHsType GhcRn -> Type -> TcM Type
    tc_lhs_type TcTyMode
    mode LHsType GhcRn
    hs_ty Type
    ek
                      ; ([(Name, TyVar)], Type) -> TcM ([(Name, TyVar)], Type)
    forall (m :: * -> *) a. Monad m => a -> m a
    return ([(Name, TyVar)]
    wcs, Type
    sig_ty) }

            ; ((Name, TyVar) -> TcM ()) -> [(Name, TyVar)] -> TcM ()
    forall (t :: * -> *) (m :: * -> *) a b.
    (Foldable t, Monad m) =>
    (a -> m b) -> t a -> m ()
    mapM_ (Name, TyVar) -> TcM ()
    emitNamedTypeHole [(Name, TyVar)]
    wcs

              -- sig_ty might have tyvars that are at a higher TcLevel (if hs_ty
              -- contains a forall). Promote these.
              -- Ex: f (x :: forall a. Proxy a -> ()) = ... x ...
              -- When we instantiate x, we have to compare the kind of the argument
              -- to a's kind, which will be a metavariable.
              -- kindGeneralizeNone does this:
            ; Type -> TcM ()
    kindGeneralizeNone Type
    sig_ty
            ; Type
    sig_ty <- Type -> TcM Type
    zonkTcType Type
    sig_ty
            ; UserTypeCtxt -> Type -> TcM ()
    checkValidType UserTypeCtxt
    ctxt Type
    sig_ty

            ; String -> SDoc -> TcM ()
    traceTc String
    "tcHsPatSigType" ([(Name, TyVar)] -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr [(Name, TyVar)]
    sig_tkv_prs)
            ; ([(Name, TyVar)], [(Name, TyVar)], Type)
    -> TcM ([(Name, TyVar)], [(Name, TyVar)], Type)
    forall (m :: * -> *) a. Monad m => a -> m a
    return ([(Name, TyVar)]
    wcs, [(Name, TyVar)]
    sig_tkv_prs, Type
    sig_ty) }
      where
        new_implicit_tv :: Name -> IOEnv (Env TcGblEnv TcLclEnv) (Name, TyVar)
    new_implicit_tv Name
    name
          = do { Type
    kind <- TcM Type
    newMetaKindVar
               ; TyVar
    tv   <- case UserTypeCtxt
    ctxt of
                           RuleSigCtxt {} -> Name -> Type -> IOEnv (Env TcGblEnv TcLclEnv) TyVar
    newSkolemTyVar Name
    name Type
    kind
                           UserTypeCtxt
    _              -> Name -> Type -> IOEnv (Env TcGblEnv TcLclEnv) TyVar
    newPatSigTyVar Name
    name Type
    kind
                           -- See Note [Typechecking pattern signature binders]
                 -- NB: tv's Name may be fresh (in the case of newPatSigTyVar)
               ; (Name, TyVar) -> IOEnv (Env TcGblEnv TcLclEnv) (Name, TyVar)
    forall (m :: * -> *) a. Monad m => a -> m a
    return (Name
    name, TyVar
    tv) }

    {- Note [Typechecking pattern signature binders]
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    See also Note [Type variables in the type environment] in GHC.Tc.Utils.
    Consider

      data T where
        MkT :: forall a. a -> (a -> Int) -> T

      f :: T -> ...
      f (MkT x (f :: b -> c)) = <blah>

    Here
     * The pattern (MkT p1 p2) creates a *skolem* type variable 'a_sk',
       It must be a skolem so that it retains its identity, and
       GHC.Tc.Errors.getSkolemInfo can thereby find the binding site for the skolem.

     * The type signature pattern (f :: b -> c) makes fresh meta-tyvars
       beta and gamma (TauTvs), and binds "b" :-> beta, "c" :-> gamma in the
       environment

     * Then unification makes beta := a_sk, gamma := Int
       That's why we must make beta and gamma a MetaTv,
       not a SkolemTv, so that it can unify to a_sk (or Int, respectively).

     * Finally, in '<blah>' we have the envt "b" :-> beta, "c" :-> gamma,
       so we return the pairs ("b" :-> beta, "c" :-> gamma) from tcHsPatSigType,

    Another example (#13881):
       fl :: forall (l :: [a]). Sing l -> Sing l
       fl (SNil :: Sing (l :: [y])) = SNil
    When we reach the pattern signature, 'l' is in scope from the
    outer 'forall':
       "a" :-> a_sk :: *
       "l" :-> l_sk :: [a_sk]
    We make up a fresh meta-TauTv, y_sig, for 'y', and kind-check
    the pattern signature
       Sing (l :: [y])
    That unifies y_sig := a_sk.  We return from tcHsPatSigType with
    the pair ("y" :-> y_sig).

    For RULE binders, though, things are a bit different (yuk).
      RULE "foo" forall (x::a) (y::[a]).  f x y = ...
    Here this really is the binding site of the type variable so we'd like
    to use a skolem, so that we get a complaint if we unify two of them
    together.  Hence the new_implicit_tv function in tcHsPatSigType.

    ************************************************************************
    *                                                                      *
            Checking kinds
    *                                                                      *
    ************************************************************************

    -}

    unifyKinds :: [LHsType GhcRn] -> [(TcType, TcKind)] -> TcM ([TcType], TcKind)
    unifyKinds :: [LHsType GhcRn] -> [(Type, Type)] -> TcM ([Type], Type)
    unifyKinds [LHsType GhcRn]
    rn_tys [(Type, Type)]
    act_kinds
      = do { Type
    kind <- TcM Type
    newMetaKindVar
           ; let check :: GenLocated SrcSpanAnnA (HsType GhcRn) -> (Type, Type) -> TcM Type
    check GenLocated SrcSpanAnnA (HsType GhcRn)
    rn_ty (Type
    ty, Type
    act_kind)
                   = HasDebugCallStack =>
    HsType GhcRn -> Type -> Type -> Type -> TcM Type
    HsType GhcRn -> Type -> Type -> Type -> TcM Type
    checkExpectedKind (GenLocated SrcSpanAnnA (HsType GhcRn) -> HsType GhcRn
    forall l e. GenLocated l e -> e
    unLoc GenLocated SrcSpanAnnA (HsType GhcRn)
    rn_ty) Type
    ty Type
    act_kind Type
    kind
           ; [Type]
    tys' <- (GenLocated SrcSpanAnnA (HsType GhcRn) -> (Type, Type) -> TcM Type)
    -> [GenLocated SrcSpanAnnA (HsType GhcRn)]
    -> [(Type, Type)]
    -> TcM [Type]
    forall (m :: * -> *) a b c.
    Applicative m =>
    (a -> b -> m c) -> [a] -> [b] -> m [c]
    zipWithM GenLocated SrcSpanAnnA (HsType GhcRn) -> (Type, Type) -> TcM Type
    check [GenLocated SrcSpanAnnA (HsType GhcRn)]
    [LHsType GhcRn]
    rn_tys [(Type, Type)]
    act_kinds
           ; ([Type], Type) -> TcM ([Type], Type)
    forall (m :: * -> *) a. Monad m => a -> m a
    return ([Type]
    tys', Type
    kind) }

    {-
    ************************************************************************
    *                                                                      *
            Sort checking kinds
    *                                                                      *
    ************************************************************************

    tcLHsKindSig converts a user-written kind to an internal, sort-checked kind.
    It does sort checking and desugaring at the same time, in one single pass.
    -}

    tcLHsKindSig :: UserTypeCtxt -> LHsKind GhcRn -> TcM Kind
    tcLHsKindSig :: UserTypeCtxt -> LHsType GhcRn -> TcM Type
    tcLHsKindSig UserTypeCtxt
    ctxt LHsType GhcRn
    hs_kind
      = TcTyMode -> UserTypeCtxt -> LHsType GhcRn -> TcM Type
    tc_lhs_kind_sig TcTyMode
    kindLevelMode UserTypeCtxt
    ctxt LHsType GhcRn
    hs_kind

    tc_lhs_kind_sig :: TcTyMode -> UserTypeCtxt -> LHsKind GhcRn -> TcM Kind
    tc_lhs_kind_sig :: TcTyMode -> UserTypeCtxt -> LHsType GhcRn -> TcM Type
    tc_lhs_kind_sig TcTyMode
    mode UserTypeCtxt
    ctxt LHsType GhcRn
    hs_kind
    -- See  Note [Recipe for checking a signature] in GHC.Tc.Gen.HsType
    -- Result is zonked
      = do { Type
    kind <- SDoc -> TcM Type -> TcM Type
    forall a. SDoc -> TcM a -> TcM a
    addErrCtxt (String -> SDoc
    text String
    "In the kind" SDoc -> SDoc -> SDoc
    <+> SDoc -> SDoc
    quotes (GenLocated SrcSpanAnnA (HsType GhcRn) -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr GenLocated SrcSpanAnnA (HsType GhcRn)
    LHsType GhcRn
    hs_kind)) (TcM Type -> TcM Type) -> TcM Type -> TcM Type
    forall a b. (a -> b) -> a -> b
    $
                     String -> TcM Type -> TcM Type
    forall a. String -> TcM a -> TcM a
    solveEqualities String
    "tcLHsKindSig" (TcM Type -> TcM Type) -> TcM Type -> TcM Type
    forall a b. (a -> b) -> a -> b
    $
                     TcTyMode -> LHsType GhcRn -> Type -> TcM Type
    tc_lhs_type TcTyMode
    mode LHsType GhcRn
    hs_kind Type
    liftedTypeKind
           ; String -> SDoc -> TcM ()
    traceTc String
    "tcLHsKindSig" (GenLocated SrcSpanAnnA (HsType GhcRn) -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr GenLocated SrcSpanAnnA (HsType GhcRn)
    LHsType GhcRn
    hs_kind SDoc -> SDoc -> SDoc
    $$ Type -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr Type
    kind)
           -- No generalization:
           ; Type -> TcM ()
    kindGeneralizeNone Type
    kind
           ; Type
    kind <- Type -> TcM Type
    zonkTcType Type
    kind
             -- This zonk is very important in the case of higher rank kinds
             -- E.g. #13879    f :: forall (p :: forall z (y::z). <blah>).
             --                          <more blah>
             --      When instantiating p's kind at occurrences of p in <more blah>
             --      it's crucial that the kind we instantiate is fully zonked,
             --      else we may fail to substitute properly

           ; UserTypeCtxt -> Type -> TcM ()
    checkValidType UserTypeCtxt
    ctxt Type
    kind
           ; String -> SDoc -> TcM ()
    traceTc String
    "tcLHsKindSig2" (Type -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr Type
    kind)
           ; Type -> TcM Type
    forall (m :: * -> *) a. Monad m => a -> m a
    return Type
    kind }

    promotionErr :: Name -> PromotionErr -> TcM a
    promotionErr :: forall a. Name -> PromotionErr -> TcM a
    promotionErr Name
    name PromotionErr
    err
      = SDoc -> TcM a
    forall a. SDoc -> TcM a
    failWithTc (SDoc -> Arity -> SDoc -> SDoc
    hang (PromotionErr -> SDoc
    pprPECategory PromotionErr
    err SDoc -> SDoc -> SDoc
    <+> SDoc -> SDoc
    quotes (Name -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr Name
    name) SDoc -> SDoc -> SDoc
    <+> String -> SDoc
    text String
    "cannot be used here")
                       Arity
    2 (SDoc -> SDoc
    parens SDoc
    reason))
      where
        reason :: SDoc
    reason = case PromotionErr
    err of
                   ConstrainedDataConPE Type
    pred
                                  -> String -> SDoc
    text String
    "it has an unpromotable context"
                                     SDoc -> SDoc -> SDoc
    <+> SDoc -> SDoc
    quotes (Type -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr Type
    pred)
                   PromotionErr
    FamDataConPE   -> String -> SDoc
    text String
    "it comes from a data family instance"
                   PromotionErr
    NoDataKindsTC  -> String -> SDoc
    text String
    "perhaps you intended to use DataKinds"
                   PromotionErr
    NoDataKindsDC  -> String -> SDoc
    text String
    "perhaps you intended to use DataKinds"
                   PromotionErr
    PatSynPE       -> String -> SDoc
    text String
    "pattern synonyms cannot be promoted"
                   PromotionErr
    RecDataConPE   -> SDoc
    same_rec_group_msg
                   PromotionErr
    ClassPE        -> SDoc
    same_rec_group_msg
                   PromotionErr
    TyConPE        -> SDoc
    same_rec_group_msg

        same_rec_group_msg :: SDoc
    same_rec_group_msg = String -> SDoc
    text String
    "it is defined and used in the same recursive group"

    {-
    ************************************************************************
    *                                                                      *
              Error messages and such
    *                                                                      *
    ************************************************************************
    -}

    -- | Make an appropriate message for an error in a function argument.
    -- Used for both expressions and types.
    funAppCtxt :: (Outputable fun, Outputable arg) => fun -> arg -> Int -> SDoc
    funAppCtxt :: forall fun arg.
    (Outputable fun, Outputable arg) =>
    fun -> arg -> Arity -> SDoc
    funAppCtxt fun
    fun arg
    arg Arity
    arg_no
      = SDoc -> Arity -> SDoc -> SDoc
    hang ([SDoc] -> SDoc
    hsep [ String -> SDoc
    text String
    "In the", Arity -> SDoc
    speakNth Arity
    arg_no, PtrString -> SDoc
    ptext (String -> PtrString
    sLit String
    "argument of"),
                        SDoc -> SDoc
    quotes (fun -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr fun
    fun) SDoc -> SDoc -> SDoc
    <> String -> SDoc
    text String
    ", namely"])
           Arity
    2 (SDoc -> SDoc
    quotes (arg -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr arg
    arg))

    -- | Add a "In the data declaration for T" or some such.
    addTyConFlavCtxt :: Name -> TyConFlavour -> TcM a -> TcM a
    addTyConFlavCtxt :: forall a. Name -> TyConFlavour -> TcM a -> TcM a
    addTyConFlavCtxt Name
    name TyConFlavour
    flav
      = SDoc -> TcM a -> TcM a
    forall a. SDoc -> TcM a -> TcM a
    addErrCtxt (SDoc -> TcM a -> TcM a) -> SDoc -> TcM a -> TcM a
    forall a b. (a -> b) -> a -> b
    $ [SDoc] -> SDoc
    hsep [ String -> SDoc
    text String
    "In the", TyConFlavour -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr TyConFlavour
    flav
                          , String -> SDoc
    text String
    "declaration for", SDoc -> SDoc
    quotes (Name -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr Name
    name) ]