(define-sequence-traverser replace
(sequence1 sequence2 &rest args &key start1 end1 start2 end2)
#!+sb-doc
- "The target sequence is destructively modified by copying successive
- elements into it from the source sequence."
+ "Destructively modifies SEQUENCE1 by copying successive elements
+into it from the SEQUENCE2.
+
+Elements are copied to the subseqeuence bounded by START1 and END1,
+from the subsequence bounded by START2 and END2. If these subsequences
+are not of the same length, then the shorter length determines how
+many elements are copied."
(declare (truly-dynamic-extent args))
(let* (;; KLUDGE: absent either rewriting FOO-REPLACE-FROM-BAR, or
;; excessively polluting DEFINE-SEQUENCE-TRAVERSER, we rebind