Class names starting with "@_" should be recognized

Minor bug:

Importing features.fea file that includes class names starting with @_, e.g:

@_2 = [absNumberSign.2 absYearSign.2 absFootnoteSign.2 absPageSign.2 absSamvatSign.2 absEndOfAyah.2 absEndOfAyah.alt.2 absEndOfAyah.altB.2];

Glyphs (Version 2.4.2 (1037)) doesn’t seem to recognize these as classes because they are ending up in the Prefix section rather than the Classes section:

It does compile OK, which is why this is a minor bug. But these class names are valid by the spec:

The part of the glyph class name after the “@” is subject to the same name restrictions that apply to a glyph name, except that its maximum length is 63.


A glyph name may be up to 63 characters in length, must be entirely comprised of characters from the following set:
A-Z a-z 0-9 . (period) _ (underscore)
and must not start with a digit or period. The only exception is the special character “.notdef”.
“twocents”, “a1”, and “_” are valid glyph names.

And in a similar vein, Glyphs didn’t detect the languagesystem directives in my imported file and put them into the languagesystem slot in the Features Prefix area.

I’ll guess this is why there is no “Arabic” in the Edit tab Features menu:

Fixed it. Thanks for the details feedback.

confirmed fix. Many thanks!