On Mon, 21 Sep 2009, Matthijs Kooijman wrote:
Hi all,
I've been fiddling around with metaobj a bit, but defining my own objects failed. After some debugging, I've reduced this to a metapost / context MkIV issue (so no metaobj specifics anymore).
What happens, is that vardefs that use @# as a placeholder in their name only work when they are defined in an external .mp file. When I define them inside context (\startMPcode or \startMPinclusions), I get funny errors (mostly "Isolated expression", which seems to mean that the macro is not defined).
I suspect this is because the way context extracts metapost code. Is this a fundamental problem, or could it be fixed?
You need to escape # inside any \startMPwhatever...\stopMPwhatever. This has to do with the fact that TeX processes the contents before they are passed to metapost, and TeX does not like isolated #. Try replacing # with \# or \string# Hans, does it make sense to parse all MP environments (ironically except \startMPenvironment, but that is almost redundant in MKIV) with a separate catcode regime where # has catcode other. After all, it is highly unlikely that anyone will define a TeX maco inside \startMPcode or \startMPinclusions. Aditya