Re: vardef with @# not working within context

[Hans Hagen <pragma@wxs.nl>]

Aditya Mahajan wrote:
> 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#

it's more that tex likes to duplicate the # internally

> 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.

how about adding

let @## = @# ;

to mp-tool.mp (you need to remake the context format in mkiv or the 
metafun format in mkii)

seems to work

Hans

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                                           Hans Hagen | PRAGMA ADE
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