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Re: Surprising behavior of eq?
From: |
tomas |
Subject: |
Re: Surprising behavior of eq? |
Date: |
Sun, 20 Sep 2020 18:18:21 +0200 |
User-agent: |
Mutt/1.5.21 (2010-09-15) |
On Sun, Sep 20, 2020 at 05:37:45PM +0200, Zelphir Kaltstahl wrote:
> Hello John, hello Stefan!
[...]
> Of course SO is not a standard. Either it is simply wrong, or I
> misunderstood "primitive values" in that phrase. I thought: "Ah strings
> are a primitive value, so eqv? should work in all cases when comparing
> strings." However, this has been debunked.
Strings are mutable in Guile, so probably not what's called "primitive
values":
scheme@(guile-user)> (define str (string-copy "the quick brown fox"))
scheme@(guile-user)> (string-set! str 6 #\a)
scheme@(guile-user)> str
$3 = "the quack brown fox"
But string literals bark at you if you try to mutate them (that's why
I slyly created that one with `string-copy'):
scheme@(guile-user)> (define str "the quick brown fox")
scheme@(guile-user)> (string-set! str 6 #\a)
ice-9/boot-9.scm:1669:16: In procedure raise-exception:
string is read-only: "the quick brown fox"
Cheers
- t
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- Surprising behavior of eq?, Zelphir Kaltstahl, 2020/09/20
- Re: Surprising behavior of eq?, Zelphir Kaltstahl, 2020/09/20
- Re: Surprising behavior of eq?, Christopher Lemmer Webber, 2020/09/20
- Re: Surprising behavior of eq?, Zelphir Kaltstahl, 2020/09/20
- Re: Surprising behavior of eq?, John Cowan, 2020/09/20
- Re: Surprising behavior of eq?, Zelphir Kaltstahl, 2020/09/20
- Re: Surprising behavior of eq?,
tomas <=
- Re: Surprising behavior of eq?, John Cowan, 2020/09/20
- Re: Surprising behavior of eq?, Linus Björnstam, 2020/09/20
- Re: Surprising behavior of eq?, John Cowan, 2020/09/20
- Re: Surprising behavior of eq?, Stefan Schmiedl, 2020/09/20
- Re: Surprising behavior of eq?, Zelphir Kaltstahl, 2020/09/20
- Re: Surprising behavior of eq?, Taylan Kammer, 2020/09/20