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Re: [Scheme-reports] Seeking review of sets and hash tables proposals
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 cowan@x
if if = then then then = else else else = if;
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