% This macro source file is from the four volume series
% "TeX in Practice" by Stephan von Bechtolsheim, published
% 1993 by Springer-Verlag, New York.
% Copyright 1993 Stephan von Bechtolsheim.
% No warranty or liability is assumed.
% This macro may be copied freely if no fees other than
% media cost or shipping charges are charged and as long
% as this copyright and the following source code itself
% is not changed. Please see the series for further information.
%
% Version: 1.0
% Date: May 1, 1993
%
%
% This source code is documented in 20.2.2, p. III-121.
% Original source in file "tokens3.TEX", starting line 263.
\wlog{L: "list-mac.tip" ["tokens3.TEX," l. 263, p. III-121]}%
% This file DOES belong to format "texip."
\InputD{compst.tip}
\catcode`\@ = 11
\def\@EmptyRefList{}
\def\EmptyListConditional #1{%
    TT\fi
    \ifx#1\@EmptyRefList
}
\newtoks\@AppendTokOne
\newtoks\@AppendTokTwo
\def\LeftAppendElement #1#2{%
    \edef\@AppendTemp{\noexpand\\{#2}}% 
    \@AppendTokOne = \expandafter{\@AppendTemp}%
    \@AppendTokTwo = \expandafter{#1}%
    \edef#1{\the\@AppendTokOne \the\@AppendTokTwo}%
}
\def\RightAppendElement #1#2{%
    \edef\@AppendTemp{\noexpand\\{#2}}% 
    \@AppendTokOne = \expandafter{\@AppendTemp}%
    \@AppendTokTwo = \expandafter{#1}%
    \edef#1{\the\@AppendTokTwo \the\@AppendTokOne}%
}
\def\CarOfList #1#2{%
    \def\@CarTemp \\##1##2\@EndCarList{\def#2{##1}}%
    \expandafter\@CarTemp#1\@EndCarList
}
\def\CdrOfList #1#2{% 
    \def\@CdrTemp \\##1##2\@EndCdrList{\def#2{##2}}% 
    \expandafter\@CdrTemp#1\@EndCdrList
}
\def\DropFirstElementOfList #1{% 
    \if\EmptyListConditional{#1}% 
        \errhelp = {\string\DropFirstElementOfList: list is
            empty. No first element to drop.}%
        \errmessage{\string\DropFirstElementOfList: List
            \noexpand#1 is empty.}%
    \else
        \def\@DropFirstElementTemp \\##1##2\@EndCdrList{\def#1{##2}}%
        \expandafter\@DropFirstElementTemp#1\@EndCdrList
    \fi
}
\def\CarCarOfList #1#2{%
    \let\@CarCarOfListList = #1%
    \DropFirstElementOfList{\@CarCarOfListList}%
    \CarOfList{\@CarCarOfListList}{#2}
}
\def\ForEveryListElement #1#2{%
    \let\@ForEveryList = #1%
    \let\@ForEveryListElementMacro = #2%
    \@ForEveryListElement
}
\def\@ForEveryListElement{%
    \if\EmptyListConditional{\@ForEveryList}%
        \let\@ForEveryListElementNext = \relax
    \else
        \CarOfList{\@ForEveryList}{\@ForEveryListElementElement}%
        \@ForEveryListElementMacro{\@ForEveryListElementElement}%
        \DropFirstElementOfList{\@ForEveryList}%
        \let\@ForEveryListElementNext = \@ForEveryListElement
    \fi
    \@ForEveryListElementNext
}
\newif\if@MemberList
\def\MemberOfListConditional #1#2{%
    TT\fi
    \@MemberListfalse
    {%
        \def\\##1{% 
            \if\StringsEqualConditional{#2}{##1}% 
                \global\@MemberListtrue
            \fi
        }%
        #1% 
    }%
    \if@MemberList
}
\def\ReverseList #1#2{%
    \def\@ReverseListOut{}%
    \ForEveryListElement{#1}{\@ReverseList}%
    \let#2 = \@ReverseListOut
}
\def\@ReverseList #1{% 
    \LeftAppendElement{\@ReverseListOut}{#1}%
}
\def\LastElementOfList #1#2{%
    \ReverseList{#1}{#1}%
    \CarOfList{#1}{#2}%
    \ReverseList{#1}{#1}%
}
\def\DropLastElementOfList #1{%
    \ReverseList{#1}{#1}%
    \DropFirstElementOfList{#1}%
    \ReverseList{#1}{#1}%
}
\def\NumberOfListElements #1#2{% 
    \let\@NumberOfListElementsList = #1%
    \def\@NumberOfListElementsCount{#2}%
    \@NumberOfListElementsCount = 0
    \@NumberOfListElements  
}
\def\@NumberOfListElements{%
    \if\EmptyListConditional{\@NumberOfListElementsList}%
        \let\@NumberOfListElementsNext = \relax
    \else
        \advance\@NumberOfListElementsCount by 1
        \DropFirstElementOfList{\@NumberOfListElementsList}%
        \let\@NumberOfListElementsNext = \@NumberOfListElements
    \fi
    \@NumberOfListElementsNext
}
\newcount\@NumberOfListElCCount
\def\NumberOfListElementsNumConditional #1{%
    0=0\fi
    \NumberOfListElements{#1}{\@NumberOfListElCCount}%
    \ifnum\@NumberOfListElCCount
}
\def\CombineTwoLists #1#2#3{%
    \def\@CombineTwoLists{\def\@CombineTwoListsResult}%
    \expandafter\expandafter\expandafter
    \expandafter\expandafter\expandafter
    \expandafter\@CombineTwoLists
    \expandafter\expandafter\expandafter{\expandafter#1#2}%
    \let #3 = \@CombineTwoListsResult
}
\catcode`\@ = 12