chickadee » srfi-228 » make-wrapper-comparator

make-wrapper-comparator type-test unwrap contents-comparatorprocedure

Returns a comparator which compares values satisfying the predicate type-test by first calling the given unwrap procedure on them, then comparing the output of that procedure with the given contents-comparator. The hash function of the wrapper comparator returns the same value as the contents-comparator run on the unwrapped value.