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* Why does assq fail when getting quoted value from a property list?
@ 2018-08-06  3:55 Cody Goodman
  2018-08-06  7:29 ` tomas
  0 siblings, 1 reply; 4+ messages in thread
From: Cody Goodman @ 2018-08-06  3:55 UTC (permalink / raw)
  To: help-gnu-emacs

This returns (urgent . 2) as I'd expect:

(assq 'urgent '((urgent . 2)))

Why does this not return the same?

(let ((lookup (plist-get '(:severity (quote urgent)) :severity)))
              (assq lookup '((urgent . 2))))

Thanks,

Cody


^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: Why does assq fail when getting quoted value from a property list?
  2018-08-06  3:55 Why does assq fail when getting quoted value from a property list? Cody Goodman
@ 2018-08-06  7:29 ` tomas
  2018-08-06 11:53   ` Noam Postavsky
  0 siblings, 1 reply; 4+ messages in thread
From: tomas @ 2018-08-06  7:29 UTC (permalink / raw)
  To: help-gnu-emacs

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On Sun, Aug 05, 2018 at 10:55:05PM -0500, Cody Goodman wrote:
> This returns (urgent . 2) as I'd expect:
> 
> (assq 'urgent '((urgent . 2)))
> 
> Why does this not return the same?
> 
> (let ((lookup (plist-get '(:severity (quote urgent)) :severity)))
>               (assq lookup '((urgent . 2))))

Because the value of (plist-get '(:severity (quote urgent) :severity)
is the symbol 'urgent (and not the symbol urgent, as you probably expect).

IOW, '(:severity (quote urgent) :severity) is quoting the 'urgent twice,
so to speak (one is the outer '(...), the other is the inner, explicit
(quote ...)

HTH
- -- tomás
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^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: Why does assq fail when getting quoted value from a property list?
  2018-08-06  7:29 ` tomas
@ 2018-08-06 11:53   ` Noam Postavsky
  2018-08-06 13:27     ` tomas
  0 siblings, 1 reply; 4+ messages in thread
From: Noam Postavsky @ 2018-08-06 11:53 UTC (permalink / raw)
  To: tomas; +Cc: Help Gnu Emacs mailing list

On 6 August 2018 at 03:29,  <tomas@tuxteam.de> wrote:

>> (let ((lookup (plist-get '(:severity (quote urgent)) :severity)))
>>               (assq lookup '((urgent . 2))))
>
> Because the value of (plist-get '(:severity (quote urgent) :severity)
> is the symbol 'urgent

You mean the list of two symbols `quote' and `urgent'.

    (equal (list 'quote 'urgent)
           (plist-get '(:severity (quote urgent)) :severity))
    ;=> t



^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: Why does assq fail when getting quoted value from a property list?
  2018-08-06 11:53   ` Noam Postavsky
@ 2018-08-06 13:27     ` tomas
  0 siblings, 0 replies; 4+ messages in thread
From: tomas @ 2018-08-06 13:27 UTC (permalink / raw)
  To: Noam Postavsky; +Cc: Help Gnu Emacs mailing list

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On Mon, Aug 06, 2018 at 07:53:51AM -0400, Noam Postavsky wrote:
> On 6 August 2018 at 03:29,  <tomas@tuxteam.de> wrote:
> 
> >> (let ((lookup (plist-get '(:severity (quote urgent)) :severity)))
> >>               (assq lookup '((urgent . 2))))
> >
> > Because the value of (plist-get '(:severity (quote urgent) :severity)
> > is the symbol 'urgent
> 
> You mean the list of two symbols `quote' and `urgent'.

Hmpf. You're right. "Evaluation" of quote happens later...

Cheers
- -- t
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^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2018-08-06 13:27 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2018-08-06  3:55 Why does assq fail when getting quoted value from a property list? Cody Goodman
2018-08-06  7:29 ` tomas
2018-08-06 11:53   ` Noam Postavsky
2018-08-06 13:27     ` tomas

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