Concurrent language tags aren't correctly recognised

[eweracs]

I'm not entirely sure where exactly to post this issue, whether in fontmake or glyphsLib. I hope here is correct.

In Glyphs, multiple language tags for a lookup can be written concurrently:
language ROM MOL;

However, this leads to an error when using fontmake to compile a ufo:
Compiling UFO failed: <features>:110:14: Expected ';'

The UFO compiler expects one language tag per lookup, it appears. Glyphs allows concurrent language tags like language AZE CRT KAZ TAT TRK;.

How can this be amended, and where?

[khaledhosny]

That would be an issue for fontTools.feaLib. Is this FEA language extension documented somewhere?

[eweracs]

Sorry about that, and thanks for pointing me to the correct repo! I'll post the issue there instead.

The multiple language tag syntax is documented in the Glyphs Handbook: https://handbook.glyphsapp.com/layout/multiple-languages-syntax/