hash for eq? Per Bothner (09 Aug 2005 07:17 UTC)
Re: hash for eq? Panu Kalliokoski (10 Aug 2005 06:18 UTC)
Re: hash for eq? Per Bothner (10 Aug 2005 06:28 UTC)

Re: hash for eq? Per Bothner 10 Aug 2005 06:26 UTC

Panu Kalliokoski wrote:
> On Tue, Aug 09, 2005 at 12:17:11AM -0700, Per Bothner wrote:
>>Should the reference implementation of make-hash-table be
>>modified so the default hash function for eq? is hash-by-identity?
>>I.e. add in the obvious place:
> In the reference implementation, this does not help any, because it has
> (define hash-by-identity hash).  If hash-by-identity were provided as a
> primitive, then yes, it would make sense.  So it's just a question of
> whether we can trust Scheme implementors that use the SRFI code
> _partially_ to notice this particular thing.

I think it would clarify the intent better, both for users (it's useful
to look at the reference implementation to see an alternative and more
formal "specification"), and for implementors (often implementors take
a reference implementations and tweak places that the reference
implementation *recommends* shoudld be tweaked).  If you make the
change I suggested, it means a port has to modify less code (and
the diffs are better localized), and it also make it clear that an
implementation *should* use hash-by-identity (if provided) as the
default hash function for eq?.
	--Per Bothner
xxxxxx@bothner.com   http://per.bothner.com/