On Fri, Apr 17, 2015 at 05:29:39PM +0200, Khaled Hosny wrote: > On Fri, Apr 17, 2015 at 05:07:31PM +0200, Frédéric Wang wrote: > > Hi all, > > > > Here is a testcase with a dev version of GNUFreeFont: > > http://fred-wang.github.io/MathFonts/GNUFreeFont/ > > > > As I understand, stretchy U+2F/U+2211/U+27E8/U+27E9 do not have a "glue" > > so we connect them using a rule > > AFAIK, The only times TeX (and by extension OpenType math implemenation) > use rules is for radical and fraction bars, everything else is done > using glyph variants and/or repeatable parts. If the font does not > provide the required glyphs no stretching happens.
The p.225 of TeXbook referenced in the code talks about how plain TeX fakes stretchy over and under braces since TeX did not support horizontal stretching, so IMO this has no place in an implemntation that does not suffer from this limitation. Regards, Khaled
