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Re: Making 'eq' == 'eql' in bignum branch

From: Paul Eggert
Subject: Re: Making 'eq' == 'eql' in bignum branch
Date: Mon, 20 Aug 2018 09:03:17 -0700
User-agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1

Andy Moreton wrote:

There will always be a performance diffrence between fixnum and bignum
values, and it may be useful for performance tuning to have a simple way
to discover where that boundary lies.

Performance nerds can use 'most-positive-fixnum' and 'most-negative-fixnum' for that sort of thing. These constants have been there for some time and are not going away. My objection is to 'bignump' and 'fixnump', which are no more necessary as primitives than 'negativep' would be.

These are used in the tests to ensure that implementation is correct,
and that values in fixnum range are always represented as fixnums, not
bignums. How do you propose to test that without these predicates ?

Tests can use 'most-positive-fixnum' and 'most-negative-fixnum', constants that tests need to use anyway in order to generate values like (1+ most-positive-fixnum). So they can survive quite well without 'bignump' and 'fixnump' as primitives.

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