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Re: hash table question
- To: Daniel L. Weinreb <DLW@alderaan.scrc.symbolics.com>
- Subject: Re: hash table question
- From: sandra%utah-orion@utah-cs.arpa (Sandra J Loosemore)
- Date: Mon, 24 Nov 86 17:31:28 MST
- Cc: sandra%utah-orion@utah-cs.arpa, common-lisp@su-ai.arpa
- In-reply-to: Daniel L. Weinreb <DLW@ALDERAAN.SCRC.Symbolics.COM>, Mon, 24 Nov 86 18:39 EST
Date: Mon, 24 Nov 86 18:39 EST
From: Daniel L. Weinreb <DLW@ALDERAAN.SCRC.Symbolics.COM>
No, it doesn't always return true. sxhash is an "equal" hash, returning
the same value for equal structures, even if they're not eq.
Fine. So what happens if the cons I just clobbered was being used as a
key in an "eq" hash table? Certainly the original cons is still "eq" to
itself after it's been clobbered. Does this mean that an "eq" hash table
*can't* look at the contents of an object to compute a hash index?
(Actually, I can't think of any reason why one would *want* to perform
destructive operations on an object that is being used as a hash key, and
would be happy to see this made "an error".)
-Sandra
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