Am 15.12.2010 um 19:40 schrieb Marco Pessotto:
Hello there.
I was writing a small macro to emulate a custom \part command, and I broke my head against \dosingleempty (but finally I won).
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It's unclear to me how the arguments are passed between macros. Probably it's just a matter of knowledge of TeX macro programming (which obviously I don't have).
Your test with \iffirstargument fails because you perform it after \startalignment which has itself a argument which sets \iffirstargument to true, a better way to check for content of the optional argument is \doifsomethingelse. \def\talpart {\dosingleempty\dotalpart} \def\dotalpart[#1]#2% {\page[right] \blank[force,2*big] \startalignment[center] \doifsomethingelse{#1} {{\bfc#1}\writetolist[talpart]{}{#1. #2}} {\writetolist[talpart]{}{#2}}% \blank[2*big] {\bfd#2} \stopalignment \page[left]} Wolfgang