Ray Dillinger scripsit: > I don't think that's the issue Vassil was talking about, but > implementation as a map requires the ability to use a custom > hash function if using a custom equality predicate.
Which, come to think of it, is a good argument for the hash-plus-equivalence magic. The current set/bag API doesn't have any way to specify a hash function, because the fact that sets and bags use a hash table is or should be an implementation detail -- but if you pass an unknown equivalence function, the implementation won't work. Granted that perhaps a record would be better than a magic procedure here, nevertheless it does begin to look like some method of packaging hash function with equivalence predicate is necessary for cleanness. -- John Cowan http://www.ccil.org/~cowan [email protected] if if = then then then = else else else = if; _______________________________________________ Scheme-reports mailing list [email protected] http://lists.scheme-reports.org/cgi-bin/mailman/listinfo/scheme-reports
