[XeTeX] \@nameuse question

[Michiel Kamermans]

Hi all,

I'm cleaning up my ucharclasses package, and wanted to move from 
ifthen/forloop to plain TeX. The Original code was:

\newcounter{iclass}
% general transition rule
\newcommand{\@transition}[3]{\XeTeXinterchartoks #1 #2=#3}
%    Use: \setUTransitions{when entering this block}{when leaving this 
block}
\newcommand{\setTransitionsFor}[3]{
     \forloop{iclass}{\the\@classstart}{\value{iclass} < 
\@nameuse{#1Class}}{
         \@transition{\the\value{iclass}}{\@nameuse{#1Class}}{{#2}}
         \@transition{\@nameuse{#1Class}}{\the\value{iclass}}{{#3}}}
     \addtocounter{iclass}{2}
     \forloop{iclass}{\value{iclass}}{\value{iclass} < \the\@classend}{
         \@transition{\the\value{iclass}}{\@nameuse{#1Class}}{{#2}}
         \@transition{\@nameuse{#1Class}}{\the\value{iclass}}{{#3}}}
     % and a binding for the transitions to and from boundary characters
     \@transition{255}{\@nameuse{#1Class}}{{#2}}
     \@transition{\@nameuse{#1Class}}{255}{{#3}}}

This works quite well, but relies on the forloop package. I replaced the 
\forloop commands with \loop<init>\if<cond><success>\repeat:

\newcommand{\setTransitionsFor}[3]{
     \loop\setcounter{iclass}{\the\@classstart}
     \if\value{iclass}<\@nameuse{#1Class}
         \@transition{\the\value{iclass}}{\@nameuse{#1Class}}{{#2}}
         \@transition{\@nameuse{#1Class}}{\the\value{iclass}}{{#3}}
         \addtocounter{iclass}{1}
     \repeat
     \addtocounter{iclass}{2}
     \loop\setcounter{iclass}{\value{iclass}}
     \if\value{iclass}<\the\@classend
         \@transition{\the\value{iclass}}{\@nameuse{#1Class}}{{#2}}
         \@transition{\@nameuse{#1Class}}{\the\value{iclass}}{{#3}}
         \addtocounter{iclass}{1}
     \repeat
     % and a binding for the transitions to and from boundary characters
     \@transition{255}{\@nameuse{#1Class}}{{#2}}
     \@transition{\@nameuse{#1Class}}{255}{{#3}}}

However, running this through xelatex tells me:

! Missing number, treated as zero.
<to be read again>
                    \#1
l.263 ...\value{iclass}}{\@nameuse{#1}Class}{{#2}}

?

What obvious protecting/immediate expansion/delayed expansion am I 
forgetting?

- Mike "Pomax" Kamermans
nihongoresources.com