Re: [9fans] Font behaviour

["rob pike" <rob@plan9.bell-labs.com>]

> There's another usurpation of a meaningful in-band value
> to signal an exception.  We gotta cut that out, it causes
> trouble eventually in almost every case I've ever sen.

Platitudes are fine in their place - I've even written a few
- but you have me at a disadvantage.  My interface is out there
to be criticised, yours is not.  What do you propose to do to
fix this problem?

I have one suggestion.  There are two kinds of zero-width runes,
genuine and synthetic.  (Actually there are three; the third is
an exercise for the reader of the code.) The synthetic ones are not
at issue, I believe - you need to do something when a character
is missing from the font and no one, not even PJW, has argued that
PJW is not an appropriate solution there.  But perhaps we can break
the symmetry in the code to distinguish the genuine zero-width runes
and process them normally, with the understanding that something
may break.  You have the code; read it, try it, play with it. I'm
about to get on a plane or I'd do some experimentation myself.

-rob