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Am Thu, 17 Nov 2016 13:07:22 +0100 schrieb Hans Hagen:
Simply using \let doesn't work when you want locally a different expansion behaviour:
! error: (font expansion): font has been expanded with different stretch limit.
(with pdflatex + lualatex), that's imho the reason why microtype copies the fonts.
in fact that is also the case with pdftex: afaik expansion and protrusion values are global and once a font is used they get frozen
Yes, exactly.
in luatex (at least the lua font loader) one can set the expansion at definition time (which is more natural but not possible in pdftex)
Yes, but I understand that -- if possible -- microtype prefers code that works in pdftex *and* luatex.
The question is if microtype can easily retrieve the current font features and if it will slow down the code much if it has to redefine fonts again and again.
that's a matter of implementation
Yes, the maintainer of microtype has been informed about the problem and can now look for a solution ... -- Ulrike Fischer http://www.troubleshooting-tex.de/