% 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 24.1.18.1, p. III-302. % Original source in file "macros4.TEX", starting line 1096. \wlog{L: "isprefix.tip" ["macros4.TEX," l. 1096, p. III-302]}% % This file DOES belong to format "texip." \InputD{compst.tip} \InputD{strleng.tip} \InputD{showx.tip} \catcode`\@ = 11 \newif\if@PrefixResult \newcount\@LengthPrefixString \newcount\@LengthMainString \def\PrefixConditional #1#2{% TT\fi \StringLength{#1}% \@LengthMainString = \StringLengthResult \StringLength{#2}% \@LengthPrefixString = \StringLengthResult \ifnum\@LengthMainString < \@LengthPrefixString \@PrefixResultfalse \else \@PrefixConditionalTwo{#1}{#2}% \fi \if@PrefixResult } \def\@PrefixConditionalTwo #1#2{% \edef\@PrefixBoth{#1#2}% \edef\@PrefixTemp{% \def\noexpand\@TestPrefix ####1#2####2\noexpand\@Del{% \noexpand\if\noexpand\EmptyStringConditional{####1}% }% }% \ShowX\@PrefixTemp \@PrefixTemp \ShowX{\@TestPrefix}% \expandafter\@TestPrefix\@PrefixBoth\@Del \@PrefixResulttrue \else \@PrefixResultfalse \fi } \catcode`\@ = 12