ucw-algo.tex

   1 % The UCW Macro Collection: Typesetting of algorithms
   2 % Written by Martin Mares <mj@ucw.cz> in 2018 and placed into public domain
   3 % -------------------------------------------------------------------------
   4
   5 \ucwdefmodule{algo}
   6
   7 %       \algo{name of the algorithm}\algalias{a longer name}
   8 %       \algin input description
   9 %       \:step
  10 %       \:step  \cmt{comment}
  11 %       \::[identifier]nested step
  12 %       \:::yet more nested step
  13 %       \algout output description
  14 %       \endalgo
  15
  16 % Localized strings
  17 \localedef{0}{alg:alg}{Algorithm}
  18 \localedef{0}{alg:proc}{Procedure}
  19 \localedef{0}{alg:func}{Function}
  20 \localedef{0}{alg:in}{Input}
  21 \localedef{0}{alg:out}{Output}
  22
  23 % Item indent
  24 \newdimen\algoindent
  25 \algoindent=2em
  26
  27 % Extra indent for nested items
  28 \newdimen\algonestindent
  29 \algonestindent=2em
  30
  31 % Width of item label
  32 \newdimen\algolabelwidth
  33 \algolabelwidth=0.5em
  34
  35 % Set up spacing (customizable)
  36 \def\algospacing{
  37         \itemnarrow=\itemindent
  38         \interitemskip=1pt
  39         \preitemizeskip=\bigskipamount
  40         \postitemizeskip=\dimexpr \bigskipamount - \parskip \relax
  41 }
  42
  43 % Set up paragraph mode for a single step of the algorithm (customizable)
  44 \def\algopar{
  45         \par
  46         \parindent=\algoindent
  47         \hangindent=\algoindent
  48         \advance\hangindent by \algolabelwidth
  49         \hangafter=1
  50         \leavevmode
  51 }
  52
  53 % Typeset step label (customizable)
  54 \def\algostep#1{\hbox to \algolabelwidth{\hss #1~~}}
  55
  56 \def\algoinit{
  57         \begingroup
  58         \algospacing
  59         \inititemize
  60         \let\:=\algoitem
  61         \def\={\leftarrow}
  62         \let\cmt=\algcmt
  63         \itemcount=0
  64 }
  65
  66 \def\typedalgo#1#2{\algoinit {\bo #1\/} \alg{#2}}
  67 \def\algo#1{\typedalgo{\localestr{alg:alg}}{#1}}
  68 \def\proc#1{\typedalgo{\localestr{alg:proc}}{#1}}
  69 \def\func#1{\typedalgo{\localestr{alg:func}}{#1}}
  70 \def\headlessalgo{\algoinit}
  71
  72 \def\endalgo{\endlist\endgroup}
  73 \let\endproc=\endalgo
  74
  75 \def\algoitem{%
  76         \ifnum\itemcount=0\par\nobreak\smallskip\fi
  77         \algopar\advance\itemcount by 1
  78         \algostep{\the\itemcount.}%
  79         \futurelet\next\algoitemh
  80 }
  81
  82 \def\algoitemh{\ifx\next:\let\next=\algohang\else\let\next=\algoitemgo\fi\next}
  83 \def\algohang:{\advance\hangindent by \algonestindent \hskip \algonestindent\futurelet\next\algoitemh}
  84 \optdef\algoitemgo{\ifx\addid\undefined\else\addid{item}{\the\itemcount}\fi}
  85
  86 \def\algin{\par\nobreak{\it \localestr{alg:in}:\/} }
  87 \def\algout{\par\nobreak\parindent=0pt{\it \localestr{alg:out}:\/} }
  88 \def\alginbreak{\hfil\break\hphantom{\it \localestr{alg:in}:\/} }
  89 \def\algalias#1{ (#1)}
  90
  91 % Algorithm name in text or in a formula
  92 \protected\def\alg#1{\leavevmode\hbox{\csc #1}}
  93
  94 % Comments
  95 \def\algcmt#1{\unskip~~\hfill\fullcmt{#1}\ignorespaces}
  96 \def\fullcmt#1{{$\triangleleft$\hskip0.5em\it #1}}