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Re: [Emacs-diffs] master cf28594 2/4: Improve doc for hash tables

From: Paul Eggert
Subject: Re: [Emacs-diffs] master cf28594 2/4: Improve doc for hash tables
Date: Mon, 22 Jul 2019 21:33:33 -0700
User-agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0

Stefan Monnier wrote:
[ Related to discussions we had about the need for fixnump and such
   things.  ]

I think we should try to try and avoid exposing the notion of "fixnum",

Oh, right. Sorry, I forgot those discussions when I made those doc changes. I installed the attached to revert most of them, and to change the code to do a right thing with user-defined hash functions that return bignums. The revised documentation is now slightly vague about what Emacs does with hash codes when using them as indexes: it now says it "can reduce them" rather than it "reduces them" modulo the length of the array. The changes to the code are in hashfn_user_defined (which now reduces bignums to fixnums) and in exec_byte_code (which no longer attempts to optimize hash tests other than eq).

Attachment: 0001-Avoid-overexposing-fixnums-for-hash-codes.patch
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