From: John Cowan <cowan@ccil.org>
To: "Linus Björnstam" <linus.internet@fastmail.se>
Cc: guile-user <guile-user@gnu.org>
Subject: Re: Surprising behavior of eq?
Date: Sun, 20 Sep 2020 17:42:27 -0400 [thread overview]
Message-ID: <CAD2gp_S8vVCFmQnThgFgjB1axAS37eZT0LqCQRTCe9tQE8GJ2g@mail.gmail.com> (raw)
In-Reply-To: <40d06884-73d4-4992-81ce-962bf59ac196@www.fastmail.com>
On Sun, Sep 20, 2020 at 4:52 PM Linus Björnstam <linus.internet@fastmail.se>
wrote:
Just a quick note on guile: if you are testing equality against literals
> guile will optimize to the fastest kind. (equal? b 27) becomes (eq? b 27).
Indeed, it's a Good Thing if equal? starts out with an eqv? test (which
should be inlined except for number comparisons) and eqv? starts out with
an eq? test (which also should be inlined). If the more fine-grained test
returns #t, the more coarse-grained one can safely return #t also. This is
independent of literals, and should IMO be done by every Scheme.
next prev parent reply other threads:[~2020-09-20 21:42 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-20 12:16 Surprising behavior of eq? Zelphir Kaltstahl
2020-09-20 12:19 ` Zelphir Kaltstahl
2020-09-20 12:58 ` Christopher Lemmer Webber
2020-09-20 13:09 ` Zelphir Kaltstahl
2020-09-20 13:52 ` John Cowan
2020-09-20 15:37 ` Zelphir Kaltstahl
2020-09-20 16:18 ` tomas
2020-09-20 17:05 ` John Cowan
2020-09-20 20:51 ` Linus Björnstam
2020-09-20 21:42 ` John Cowan [this message]
2020-09-20 13:57 ` Stefan Schmiedl
2020-09-20 15:42 ` Zelphir Kaltstahl
2020-09-20 17:26 ` Taylan Kammer
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