[fea spec] Confusion around gpos with inline pair kern rule

[cmyr]

According to http://adobe-type-tools.github.io/afdko/OpenTypeFeatureFileSpecification.html#example-3c, the following two rules should be equivalent:

position s f' 10 t period;
position s f' t 10 period;

however afdko does not parse the second statement, and reports,

Positioning values are allowed only in the marked glyph sequence, or after the final glyph node when only one glyph node is marked.

I think that afdko is right and the spec is wrong, here? the specified value should always be associated with the marked glyph, so allowing it to appear at an arbitrary position in the lookahead sequence is confusing and difficult to parse.

[frankrolf]

I think this may be a typo.

pos s f' t period 10; does work; which is equivalent to the very common pos A V -20; (which can also be written as pos A' -20 V;)

[cmyr]

I agree :)