keymap-utils.tex

\let\ex=\expandafter
\def\eat#1{}
\def\letcs#1#2{\ex\ex\ex \let\ex\ex \csname#1\endcsname \csname#2\endcsname}
\def\defcs#1#2{\def\defcstmp{#2}\letcs{#1}{defcstmp}}

\def\for#1#2#3#4{%
\if\in#2%
\defcs{endloop#1}{}%
\ex\def\csname loop#1\endcsname##1{%
\ex\if\csname endloop#1\endcsname##1\else%
\defcs{#1}{##1}%
#4\relax%
\letcs{looptmp}{loop#1}%
\ex\ex\ex\looptmp\fi}%
\letcs{looptmp}{loop#1}%
\ex\looptmp#3\csname endloop#3\endcsname%
\else%
\csname count#1\endcsname #2\relax%
\defcs{loop#1}{%
#4\relax%
\advance\csname count#1\endcsname 1\relax%
\ifnum\csname count#1\endcsname<#3%
\letcs{looptmp}{loop#1}%
\ex\ex\ex\looptmp\fi}\csname loop#1\endcsname%
\fi%
}