lists.sty

% This file is part of eclecTeX, a multi-purpose LaTeX library.
%
% © 2009-2013 Sebastián González Montesinos.
%
% This work may be distributed and/or modified under the conditions of
% the LaTeX Project Public License version 1.3 or later.
%
% This work has the LPPL maintenance status `maintained'.
% The Current Maintainer of this work is Sebastián González.

\NeedsTeXFormat{LaTeX2e}[1999/12/01]

\ProvidesPackage{eclectex/lists}
  [2013/07/11 v0.0 List management utilities.]

\ProcessOptions\relax

% ---[ Packages ]---

\RequirePackage{etoolbox}
\RequirePackage{pgffor}
\RequirePackage{pgfkeys}

% ---[ Commands ]---

%% List creation.

\newcommand{\listConcat}[3]
  {\edef\the@first@list{#1}%
   \edef\the@second@list{#2}%
   \xdef#3%
     {\ifdefvoid{\the@first@list}
        {\the@second@list}
        {\ifdefvoid{\the@second@list}
           {\the@first@list}
           {\the@first@list,\the@second@list}}}}

\newcommand{\listSplit}[4]
  {\edef\the@list{#1}%
   \pgfmathparse{int(#2)}\edef\the@split@pos{\pgfmathresult}%
   \xdef#3{}% first result
   \xdef#4{}% second result
   \foreach \entry [count=\n] in \the@list
     {\ifnumless{\n}{\the@split@pos}
        {\xdef#3{\ifdefvoid{#3}{}{#3,}\entry}}
        {\xdef#4{\ifdefvoid{#4}{}{#4,}\entry}}}}

\newcommand{\listHeadTail}[3]
  {\listSplit{#1}{2}{#2}{#3}}

\newcommand{\listTail}[2]
  {\listHeadTail{#1}{\list@dummy}{#2}}

\newcommand{\listLast}[3]
  {\edef\the@list{#1}%
   \edef\list@tail@len{#2}%
   \xdef#3{}% result
   \listLength{\the@list}{\the@list@len}%
   \listSplit{\the@list}{\the@list@len-\list@tail@len+1}{\list@dummy}{#3}}

\newcommand{\listInclude}[2]
  {\edef\new@item{#2}
   \ifdefvoid{#1}{}
     {\foreach \existing@item in #1
        {\ifx\new@item\existing@item
           \gdef\new@item{}
           \breakforeach
         \fi}}%
   \ifdefvoid{\new@item}{}
     {\ifdefvoid{#1}
       % first keyword
       {\xdef#1{\new@item}}
       % subsequent keywords
       {\xdef#1{#1,\new@item}}}}

%% List queries.

\newcommand{\listLength}[2]
  {\edef\the@list{#1}%
   \foreach \entry [count=#2] in \the@list {}}

\newcommand{\listNth}[3]
  {\edef\the@list{#1}%
   \edef\the@entry@pos{#2}%
   \edef#3{}% empty unless found
   \foreach \entry [count=\n] in \the@list
     {\ifnumequal{\n}{\the@entry@pos}
        {\xdef#3{\entry}%
         \breakforeach}{}}}

\newcommand{\listHead}[2]
  {\listNth{#1}{1}{#2}}

%% List enumeration utilities.

\pgfkeys{eclectex/lists/.is family, eclectex/lists,
  startmark/.store in=\list@startmark, startmark/.value required,
  firstsep/.store in=\list@firstsep, firstsep/.value required,
  innersep/.store in=\list@innersep, innersep/.value required,
  lastsep/.store in=\list@lastsep, lastsep/.value required,
  endmark/.store in=\list@endmark, endmark/.value required,
  map/.code={\let\list@map=#1},
  plain/.style=
    {startmark={},
     firstsep={{, }},
     innersep={\list@firstsep},
     lastsep={\list@innersep},
     endmark={},
     map=\list@map@identity},
  text/.style=
    {plain, lastsep={{ and }}},
  phrase/.style=
    {text, endmark={.}},
  oneperline/.style=
    {plain, firstsep={\\}, innersep={\\}, lastsep={\\}},
  debug/.style=
    {startmark={s:}, firstsep={:fs:}, innersep={:is:},
     lastsep={:ls:}, endmark={:e}}}

\newcommand{\list@map@identity}[1]{#1} % identity macro

\newcommand{\listEnumeration}[2][]
  {\pgfkeys{eclectex/lists, plain, #1}%
   \edef\the@list{#2}%
   \listLength{\the@list}{\the@list@length}%
   \foreach \entry [count=\entry@pos] in \the@list
     {\ifdefvoid{\entry}{}
        {\ifnumequal{\entry@pos}{1}
           {\list@startmark%
            \list@map{\entry}%
            \ifnumequal{\the@list@length}{2}
              {\list@lastsep} % give precedence to lastsep
              {\ifnumequal{\the@list@length}{1}
                 {\list@endmark}
                 {\list@firstsep}}}
           {\list@map{\entry}%
            \ifnumless{\entry@pos}{\the@list@length-1}
              {\list@innersep}
              {\ifnumless{\entry@pos}{\the@list@length}
                 {\list@lastsep}
                 {\list@endmark}}}}}}

%% Command definition utilities.

\newcommand{\defcsList}[2]
  {\foreach \entry [count=\n] in {#1}
     {\listNth{#2}{\n}{\entrydef}%
      \csxdef{\entry}{\entrydef}}}