[metapost] [mp-form.mp and negative numbers

[Dan Luecking]

It appears that metafun's initialize_numbers is buggy. Or perhaps it
was never meant to be used alone. That particular function is defined
in mp-text.mp and calls
   init_numbers(textext.raw($-$),textext.raw($1$),...). The
macro textext appears to return "unknown" if some quantity called
texpictures[noftexpictures] is unknown. This appears to be the
case when textext is first called. Thus the minus sign picture
is unknown.

Other uses of metafun (within context, for example) might arrange for
that variable to be known.

The following work-around might or might not be useful. I only tested
it on stephan's example:

   noftexpictures:=0;
   picture texpictures[];
   texpictures1 := btex$-$etex;

Use after metafun is input but before any calls to format().


Dan


Daniel H. Luecking
Department of Mathematical Sciences
University of Arkansas
"Dubito ergo cogito, cogito ergo sum" --Descarte