fonttools/Tests/feaLib/data/spec5fi1.fea

# OpenType Feature File specification, section 5.f.i, example 1
# "Specifying a Chain Sub rule and marking sub-runs"
# http://www.adobe.com/devnet/opentype/afdko/topic_feature_file_syntax.html

languagesystem latn dflt;

lookup CNTXT_LIGS {
    sub f i by f_i;
    sub c t by c_t;
} CNTXT_LIGS;

lookup CNTXT_SUB {
    sub n by n.end;
    sub s by s.end;
} CNTXT_SUB;
 
feature test {
    sub [a e i o u] f' lookup CNTXT_LIGS i' n' lookup CNTXT_SUB;
    sub [a e i o u] c' lookup CNTXT_LIGS t' s' lookup CNTXT_SUB;
} test;