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{en}{alg:alg}{Algorithm}
  18 \localedef{en}{alg:proc}{Procedure}
  19 \localedef{en}{alg:in}{Input}
  20 \localedef{en}{alg:out}{Output}
  21
  22 % Item indent
  23 \newdimen\algoindent
  24 \algoindent=2em
  25
  26 % Extra indent for nested items
  27 \newdimen\algonestindent
  28 \algonestindent=2em
  29
  30 % Width of item label
  31 \newdimen\algolabelwidth
  32 \algolabelwidth=0.5em
  33
  34 % Set up spacing (customizable)
  35 \def\algospacing{
  36         \itemnarrow=\itemindent
  37         \interitemskip=1pt
  38         \preitemizeskip=\bigskipamount
  39         \postitemizeskip=\dimexpr \bigskipamount - \parskip \relax
  40 }
  41
  42 % Set up paragraph mode for a single step of the algorithm (customizable)
  43 \def\algopar{
  44         \par
  45         \parindent=\algoindent
  46         \hangindent=\algoindent
  47         \advance\hangindent by \algolabelwidth
  48         \hangafter=1
  49         \leavevmode
  50 }
  51
  52 % Typeset step label (customizable)
  53 \def\algostep#1{\hbox to \algolabelwidth{\hss #1~~}}
  54
  55 \def\algoinit{
  56         \goodbreak
  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\headlessalgo{\algoinit}
  70
  71 \def\endalgo{\goodbreak\endlist\endgroup}
  72 \let\endproc=\endalgo
  73
  74 \def\algoitem{%
  75         \ifnum\itemcount=0\par\nobreak\smallskip\fi
  76         \algopar\advance\itemcount by 1
  77         \algostep{\the\itemcount.}%
  78         \futurelet\next\algoitemh
  79 }
  80
  81 \def\algoitemh{\ifx\next:\let\next=\algohang\else\let\next=\algoitemgo\fi\next}
  82 \def\algohang:{\advance\hangindent by \algonestindent \hskip \algonestindent\futurelet\next\algoitemh}
  83 \optdef\algoitemgo{\ifx\addid\undefined\else\addid{item}{\the\itemcount}\fi}
  84
  85 \def\algin{\par\nobreak{\it \localestr{alg:in}:\/} }
  86 \def\algout{\par\nobreak\parindent=0pt{\it \localestr{alg:in}:\/} }
  87 \def\alginbreak{\hfil\break\hphantom{\it \localestr{alg:out}:\/} }
  88 \def\algalias#1{ (#1)}
  89
  90 % Algorithm name in text or in a formula
  91 \protected\def\alg#1{\leavevmode\hbox{\csc #1}}
  92
  93 % Comments
  94 \def\algcmt#1{\unskip~~\hfill\fullcmt{#1}\ignorespaces}
  95 \def\fullcmt#1{{$\triangleleft$\hskip0.5em\it #1}}