General ⇒ Splitting a string at the last comma

[gkamel]

I have the following macro:

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\def\MyMacro{{a,b,c},5}

and I would like to separate the 'a,b,c' part into one macro, say \MyMacroLeft, and the '5' into another macro, \MyMacroRight. Could anyone give me some hints as to the most efficient way of achieving this.

Many thanks.

[josephwright]

If you know that there will be a comma in \MyMacro:

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\def\SplitMyMacro{%
  \expandafter\SplitMyMacroAux\SplitMyMacro\stop
}
\def\SplitMyMacroAux#1,#2\stop{%
  \def\MyMacroLeft{#1}%
  \def\MyMacroRight{#2}%
}

[gkamel]

Joseph, many thanks for your reply.. after a small correction, it worked perfectly --- the second line should be:

Code: Select all

\expandafter\SplitMyMacroAux\MyMacro\stop

Thanks again.