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*To*: common-lisp@sail.stanford.edu*Subject*: What have hashing and equality to do with each other?*From*: David Vinayak Wallace <Gumby@MCC.COM>*Date*: Mon, 4 Jul 88 01:55 CDT*In-reply-to*: <19880703165454.6.GREENWALD@SWALLOW.SCRC.Symbolics.COM>

There has been some discussion of hashing algorithms spawned by the assertion that (= (compute-hash-index-for a) (compute-hash-index-for b)) is a sufficient definition of (equal a b). Nobody has said so, but "it ain't so!" The point of hashing is to map a large, sparse space into a smaller (hopefully more) dense one. Once you compute a hash index you have to peek into the table and look for a collision (what you do then is up to you). What's this rumour I heard about the CLOS people having defined EQUAL as a generic function....

**References**:**EQUAL, and hash tables, and value/object distinctions***From:*Michael Greenwald <Greenwald@STONY-BROOK.SCRC.Symbolics.COM>

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