This defines hooks into the humdrum module to enable it to parse Kern format spines. The predicates exported are hum_data_hook//2 and hum_duration_hook/3.

 kern_duration(+S:data, -D:rational) is det

Determines the duration of a given Kern data term.

 kern_pitch(+S:data, -P:pitch) is nondet

True when P is one of the pitches contained in a Kern data term.

 kern_rest(+S:data) is nondet

True when Kern data term S signifies a rest.