Returns a list of subsequences of a sequence, split at elements for which a predicate returns true.
split-sequence-if predicate sequence &key start end key coalesce-separators => result
A function designator.
Bounding index designators for sequence.
A function designator or
A generalized boolean.
A list of sequences.
split-sequence-if returns a list of subsequences of sequence (between start and end), split by where the function predicate returns true for an element. The structure of sequence is not changed and the elements identified by the predicate are not included in the resulting sequences.
If non-nil, the function key is applied to the elements of sequence before predicate is called.
If coalesce-separators is true, then empty sequences are omitted from result.
LispWorks User Guide and Reference Manual - 20 Sep 2017