Cdtjkyj

I'd like to use the command foo with an optional argument to step and print the counter value iterated according to the number passed.

So, for example, foo[5] should step the counter 5 times, one by one.

(!) Note that it is not the same as stepcounter{}{5}.

MWE

documentclass{report}



newcounter{mycount}

setcounter{mycount}{0}

newcommand{foo}{stepcounter{mycount}counter is textbf{themycount}}



begin{document}

first use: foo



second use: foo



now using with option to iterate: foo[2]



medskip



textit{desired output from line above should be:}



medskip



now using with option to iterate: counter is textbf{3,4}



end{document}

With expl3 it's just a few lines.

documentclass{report}

usepackage{xparse}



newcounter{mycount}

setcounter{mycount}{0}



ExplSyntaxOn

NewDocumentCommand{foo}{O{1}}

 {

  int_compare:nT { #1 > 0 }

   {

    int_compare:nTF { #1 = 1 } {counter~is} {counters~are}~

    stepcounter{mycount}

    textbf{themycount}

    prg_replicate:nn { #1 - 1 } {,stepcounter{mycount}textbf{themycount}}

   }

 }

ExplSyntaxOff



begin{document}

first use: foo



second use: foo



now using with option to iterate: foo[2]



now using with option to iterate: counters are textbf{3,4}



foo[5]



end{document}

The trick is to do the first iteration and then proceed again adding first a comma.

If the number passed is zero or less nothing happens.

Here is an approach using multido for looping and a delayed delimiter definition:

documentclass{article}



usepackage{multido}



newcounter{mycount}



newcommand{foo}[1][1]{%

  counter%

  ifnum#1>1relax s areelse space isfi

  space

  % https://tex.stackexchange.com/a/89187/5764

  defitemdelim{unskipspacedefitemdelim{,space}}% Item delimiter delayed by one cycle

  {bfseriesmultido{i=1+1}{#1}{itemdelim stepcounter{mycount}themycount}}%

}



begin{document}



first use: foo



second use: foo



now using with option to iterate: foo[2]



medskip



textit{desired output from line above should be:}



medskip



now using with option to iterate: counters are textbf{3, 4}



end{document}

With pgffor it is even less lines.

documentclass{report}

usepackage{pgffor}

newcounter{mycount}

setcounter{mycount}{0}

newcommand{foo}[1][1]{counter is foreach X [count=Y] in

{1,...,#1}{stepcounter{mycount}%

textbf{themycount}ifnumY=#1%

else%

,fi}}



begin{document}

first use: foo



second use: foo



now using with option to iterate: foo[2]



end{document}

Here is short code with multido, xparse and etoolbox:

documentclass{report}

usepackage{multido}

usepackage{xparse, etoolbox}

newcounter{mycount}

setcounter{mycount}{0}

NewDocumentCommand{foo}{O{1}}{counter is multido{i=1+1}{#1}{stepcounter{mycount}textbf{themycount}ifnumless{multidocount}{#1}{,,}{.}}}



begin{document}



first use: foo



second use: foo



now using with option to iterate: foo[5]



end{document}