Metafont optional parameters

[Owen Lamb]

Hi all,

I'd like to add an optional parameter for smuflcode to fet_beginchar, so
that I don't have to take two lines redeclaring the variable in every
glyph. Ideally, it won't have to be optional once every character has it,
but in the meantime, it would help with testing individual characters' new
encodings.

I wasn't able to find whether MF supports optional parameters, only that
certain built-in functions have them. Does anyone with MF experience know
if it does, and, if so, how to put one in?

Thanks,
Owen