New in version 1.1.
Truncate subruns of like elements in sequence to length 1:
abjad> from abjad.tools import sequencetools
abjad> sequencetools.truncate_runs_in_sequence([1, 1, 2, 3, 3, 3, 9, 4, 4, 4])
[1, 2, 3, 9, 4]
Return empty list when sequence is empty:
abjad> sequencetools.truncate_runs_in_sequence([])
[]
Raise type error when sequence is not a list.
Return new list.
Changed in version 2.0: renamed sequencetools.truncate_subruns() to sequencetools.truncate_runs_in_sequence().