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From: Xavier Leroy <Xavier.Leroy@inria.fr>
To: Thomas Fischbacher <Thomas.Fischbacher@Physik.Uni-Muenchen.DE>
Cc: Christian Lindig <lindig@cs.uni-sb.de>, Caml List <caml-list@inria.fr>
Subject: Re: [Caml-list] EQ hash tables?
Date: Wed, 12 Oct 2005 17:06:24 +0200	[thread overview]
Message-ID: <434D2670.7000507@inria.fr> (raw)
In-Reply-To: <Pine.LNX.4.61.0510121304510.13519@eiger.cip.physik.uni-muenchen.de>

> Hm, okay. I agree that this does give me the same semantics.
> But doesn't this degrade expected lookup performance to an O(n) list
> lookup if I put a lot of stuff into the hash which is (=) but not (==)?

Yes, of course.  It depends on your application.  For things like
hash-consing, this approach (standard hash function + comparison finer
than (=)) can still work well.  Alternatively, you can always put
unique integers in the data type used as key.

- Xavier Leroy



  reply	other threads:[~2005-10-12 15:06 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2005-10-10 13:42 [Caml-list] possible to define a type where = is forbidden ? yoann padioleau
2005-10-10 15:04 ` Thomas Fischbacher
2005-10-11 14:56   ` EQ hash tables? Thomas Fischbacher
2005-10-12  7:41     ` [Caml-list] " Hendrik Tews
2005-10-12  8:02     ` Xavier Leroy
2005-10-12 11:11       ` Thomas Fischbacher
2005-10-12 15:06         ` Xavier Leroy [this message]
2005-10-12 17:53           ` Thomas Fischbacher

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