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Re: Are two symbols `equal' iff they are `eq'?
From: |
Eli Zaretskii |
Subject: |
Re: Are two symbols `equal' iff they are `eq'? |
Date: |
Sun, 09 Aug 2015 21:19:53 +0300 |
> From: Marcin Borkowski <mbork@mbork.pl>
> Date: Sun, 09 Aug 2015 17:45:31 +0200
>
> >> >From the capitalization I would guess that QUIT is a C macro. From its
> >> name I would guess that anything after it is irrelevant;-). Well,
> >> joking aside, I found its definition in the source; do I get it right
> >> that it quits if something like C-g happens?
> >
> > Yes.
> >
> >> If yes, I'd be curious why it is here.
> >
> > To allow the user to interrupt a (potentially) long operation.
>
> That's obvious, I just wondered why at this point.
Because that point is traversed every recursion, so we check for C-g
on each "iteration", so to say.
> >> Apart from that, it seems that I was right: `equal' for
> >> symbols just calls `eq' (C EQ, not Lisp eq, to be more precise).
> >
> > What else could it possibly do?
>
> It could e.g. compare the string representation, so two symbols with the
> same name but in different obarrays, or one interned and the other not,
> could be equal but not eq.
I'm sure you understand how all of those would make no sense as
"equality" of any kind.
> (I'm not sure whether this would be useful, though - just a
> thought.)
If it won't be useful, why would someone do it?
- Re: Are two symbols `equal' iff they are `eq'?, (continued)
Re: Are two symbols `equal' iff they are `eq'?, Joost Kremers, 2015/08/08
- Re: Are two symbols `equal' iff they are `eq'?, Ian Zimmerman, 2015/08/09
- Re: Are two symbols `equal' iff they are `eq'?, Marcin Borkowski, 2015/08/09
- Re: Are two symbols `equal' iff they are `eq'?, Michael Heerdegen, 2015/08/09
- Re: Are two symbols `equal' iff they are `eq'?, Marcin Borkowski, 2015/08/09
- Re: Are two symbols `equal' iff they are `eq'?, Eli Zaretskii, 2015/08/09
- Re: Are two symbols `equal' iff they are `eq'?, Marcin Borkowski, 2015/08/09
- Re: Are two symbols `equal' iff they are `eq'?,
Eli Zaretskii <=
- Re: Are two symbols `equal' iff they are `eq'?, Marcin Borkowski, 2015/08/09
- Re: Are two symbols `equal' iff they are `eq'?, Nicolas Richard, 2015/08/10
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Re: Are two symbols `equal' iff they are `eq'?, Marcin Borkowski, 2015/08/09
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