chickadee » srfi-113 » set-replace

set-replace set elementprocedure

The set-replace procedure returns a newly allocated set that uses the same comparator as set and contains all the values of set except as follows: If element is equal (in the sense of set's comparator) to an existing member of set, then that member is omitted and replaced by element. If there is no such element in set, then set is returned unchanged.