カウンタ値を全角数字で出力する完全展開可能な命令 \zarabic を定義する

test-zarabic.tex

%!uplatex
\documentclass[autodetect-engine,dvipdfmx]{jsarticle}
\usepackage{pgffor}
\usepackage{xcolor}
\usepackage{zarabic}

\newcounter{testCounter}

\makeatletter
\def\test#1{%
  \setcounter{testCounter}{#1}%
  Testing \arabic{testCounter} :
  \begingroup
  \kansujichar0=`０
  \kansujichar1=`１
  \kansujichar2=`２
  \kansujichar3=`３
  \kansujichar4=`４
  \kansujichar5=`５
  \kansujichar6=`６
  \kansujichar7=`７
  \kansujichar8=`８
  \kansujichar9=`９
  \xdef\test@a{\kansuji\csname c@testCounter\endcsname}%
  \endgroup
  \edef\test@b{\zarabic{testCounter}}%
  \ifx\test@a\test@b \textcolor{blue}{OK}（\test@b ）\else \textcolor{red}{NG!}\fi
  \par
}
\makeatother

\begin{document}

\foreach \x in {0,...,999}{\test{\x}}

\foreach \x in {0,...,999}{\pgfmathrandom{0,9999999}\test{\pgfmathresult}}

\end{document}

zarabic.sty

\def\zarabic#1{\expandafter\zarabic@ZERO\the\csname c@#1\endcsname 0\relax}
\def\zarabic@ZERO#10#2\relax{%
  \if"#2"%
    \zarabic@ONE#11\relax
  \else
    \zarabic@ONE#11\relax ０\zarabic@ZERO#2\relax
  \fi}
\def\zarabic@ONE#11#2\relax{%
  \if"#2"%
    \zarabic@TWO#12\relax
  \else
    \zarabic@TWO#12\relax １\zarabic@ONE#2\relax
  \fi}
\def\zarabic@TWO#12#2\relax{%
  \if"#2"%
    \zarabic@THREE#13\relax
  \else
    \zarabic@THREE#13\relax ２\zarabic@TWO#2\relax
  \fi}
\def\zarabic@THREE#13#2\relax{%
  \if"#2"%
    \zarabic@FOUR#14\relax
  \else
    \zarabic@FOUR#14\relax ３\zarabic@THREE#2\relax
  \fi}
\def\zarabic@FOUR#14#2\relax{%
  \if"#2"%
    \zarabic@FIVE#15\relax
  \else
    \zarabic@FIVE#15\relax ４\zarabic@FOUR#2\relax
  \fi}
\def\zarabic@FIVE#15#2\relax{%
  \if"#2"%
    \zarabic@SIX#16\relax
  \else
    \zarabic@SIX#16\relax ５\zarabic@FIVE#2\relax
  \fi}
\def\zarabic@SIX#16#2\relax{%
  \if"#2"%
    \zarabic@SEVEN#17\relax
  \else
    \zarabic@SEVEN#17\relax ６\zarabic@SIX#2\relax
  \fi}
\def\zarabic@SEVEN#17#2\relax{%
  \if"#2"%
    \zarabic@EIGHT#18\relax
  \else
    \zarabic@EIGHT#18\relax ７\zarabic@SEVEN#2\relax
  \fi}
\def\zarabic@EIGHT#18#2\relax{%
  \if"#2"%
    \zarabic@NINE#19\relax
  \else
    \zarabic@NINE#19\relax ８\zarabic@EIGHT#2\relax
  \fi}
\def\zarabic@NINE#19#2\relax{%
  \if"#2"%
    #1%
  \else
    #1９\zarabic@NINE#2\relax
  \fi}