Data.Version

base-4.16.0.0: Basic libraries

Copyright | (c) The University of Glasgow 2004
License | BSD-style (see the file libraries/base/LICENSE)
Maintainer | libraries@haskell.org
Stability | experimental
Portability | non-portable (local universal quantification in ReadP)
Safe Haskell | Safe
Language | Haskell2010

Data.Version

Contents

- The `Version` type
- A concrete representation of `Version`
- Constructor function

Description

A general library for representation and manipulation of versions.

Versioning schemes are many and varied, so the version representation provided by this library is intended to be a compromise between complete generality, where almost no common functionality could reasonably be provided, and fixing a particular versioning scheme, which would probably be too restrictive.

So the approach taken here is to provide a representation which subsumes many of the versioning schemes commonly in use, and we provide implementations of `Eq`, `Ord` and conversion to/from `String` which will be appropriate for some applications, but not all.

Synopsis

- data Version = Version {
  - versionBranch :: [Int]
  - versionTags :: [String]
  }
- showVersion :: Version -> String
- parseVersion :: ReadP Version
- makeVersion :: [Int] -> Version

# The `Version` type

data Version Source #

A `Version` represents the version of a software entity.

An instance of `Eq` is provided, which implements exact equality modulo reordering of the tags in the `versionTags` field.

An instance of `Ord` is also provided, which gives lexicographic ordering on the `versionBranch` fields (i.e. 2.1 > 2.0, 1.2.3 > 1.2.2, etc.). This is expected to be sufficient for many uses, but note that you may need to use a more specific ordering for your versioning scheme. For example, some versioning schemes may include pre-releases which have tags `"pre1"`, `"pre2"`, and so on, and these would need to be taken into account when determining ordering. In some cases, date ordering may be more appropriate, so the application would have to look for `date` tags in the `versionTags` field and compare those. The bottom line is, don't always assume that `compare` and other `Ord` operations are the right thing for every `Version`.

Similarly, concrete representations of versions may differ. One possible concrete representation is provided (see `showVersion` and `parseVersion`), but depending on the application a different concrete representation may be more appropriate.

Constructors

Version |
Fields versionBranch :: [Int] The numeric branch for this version. This reflects the fact that most software versions are tree-structured; there is a main trunk which is tagged with versions at various points (1,2,3...), and the first branch off the trunk after version 3 is 3.1, the second branch off the trunk after version 3 is 3.2, and so on. The tree can be branched arbitrarily, just by adding more digits. We represent the branch as a list of `Int`, so version 3.2.1 becomes [3,2,1]. Lexicographic ordering (i.e. the default instance of `Ord` for `[Int]`) gives the natural ordering of branches. versionTags :: [String] Deprecated: See GHC ticket #2496 A version can be tagged with an arbitrary list of strings. The interpretation of the list of tags is entirely dependent on the entity that this version applies to.

#### Instances

Instances details

Data Version Source # | Since: base-4.7.0.0
Instance details Defined in Data.Data Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Version -> c Version Source # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c Version Source # toConstr :: Version -> Constr Source # dataTypeOf :: Version -> DataType Source # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c Version) Source # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c Version) Source # gmapT :: (forall b. Data b => b -> b) -> Version -> Version Source # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Version -> r Source # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Version -> r Source # gmapQ :: (forall d. Data d => d -> u) -> Version -> [u] Source # gmapQi :: Int -> (forall d. Data d => d -> u) -> Version -> u Source # gmapM :: Monad m => (forall d. Data d => d -> m d) -> Version -> m Version Source # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Version -> m Version Source # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Version -> m Version Source #
IsList Version Source # | Since: base-4.8.0.0
Instance details Defined in GHC.Exts Associated Types type Item Version Source # Methods fromList :: [Item Version] -> Version Source # fromListN :: Int -> [Item Version] -> Version Source # toList :: Version -> [Item Version] Source #
Generic Version Source # |
Instance details Defined in Data.Version Associated Types type Rep Version :: Type -> Type Source # Methods from :: Version -> Rep Version x Source # to :: Rep Version x -> Version Source #
Read Version Source # | Since: base-2.1
Instance details Defined in Data.Version Methods readsPrec :: Int -> ReadS Version Source # readList :: ReadS [Version] Source # readPrec :: ReadPrec Version Source # readListPrec :: ReadPrec [Version] Source #
Show Version Source # | Since: base-2.1
Instance details Defined in Data.Version Methods showsPrec :: Int -> Version -> ShowS Source # show :: Version -> String Source # showList :: [Version] -> ShowS Source #
Eq Version Source # | Since: base-2.1
Instance details Defined in Data.Version Methods (==) :: Version -> Version -> Bool Source # (/=) :: Version -> Version -> Bool Source #
Ord Version Source # | Since: base-2.1
Instance details Defined in Data.Version Methods compare :: Version -> Version -> Ordering Source # (<) :: Version -> Version -> Bool Source # (<=) :: Version -> Version -> Bool Source # (>) :: Version -> Version -> Bool Source # (>=) :: Version -> Version -> Bool Source # max :: Version -> Version -> Version Source # min :: Version -> Version -> Version Source #
type Item Version Source # |
Instance details Defined in GHC.Exts type Item Version = Int
type Rep Version Source # | Since: base-4.9.0.0
Instance details Defined in Data.Version type Rep Version = D1 ('MetaData "Version" "Data.Version" "base" 'False) (C1 ('MetaCons "Version" 'PrefixI 'True) (S1 ('MetaSel ('Just "versionBranch") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 [Int]) :*: S1 ('MetaSel ('Just "versionTags") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 [String])))

# A concrete representation of `Version`

showVersion :: Version -> String Source #

Provides one possible concrete representation for `Version`. For a version with `versionBranch` `= [1,2,3]` and `versionTags` `= ["tag1","tag2"]`, the output will be `1.2.3-tag1-tag2`.

parseVersion :: ReadP Version Source #

A parser for versions in the format produced by `showVersion`.

# Constructor function

makeVersion :: [Int] -> Version Source #

Construct tag-less `Version`

Since: base-4.8.0.0