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From: "Andreas Röhler" <andreas.roehler@easy-emacs.de>
To: Help Gnu Emacs mailing list <help-gnu-emacs@gnu.org>
Subject: (copy-marker nil)
Date: Mon, 7 May 2018 10:19:31 +0200	[thread overview]
Message-ID: <364c8f2d-06ab-4f81-852f-eb3bac7a0615@easy-emacs.de> (raw)

Hi,

being surprised WRT behavior of copy-marker:

(setq a (copy-marker nil)) -> #<marker in no buffer>
(markerp a) -> t
a -> #<marker in no buffer>

Is taking nil by copy-marker reasonable?

Wanted to check for a valid buffer position, which doesn't seem possible 
that way. While without copy-marker, the variable a would be set to nil, 
now the result evaluates to  #<marker in no buffer>, which is a kind of t.


Cheers,

Andreas



             reply	other threads:[~2018-05-07  8:19 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-05-07  8:19 Andreas Röhler [this message]
2018-05-07 13:39 ` (copy-marker nil) John Mastro
2018-05-07 14:23   ` Andreas Röhler
2018-05-07 13:55 ` Noam Postavsky
2018-05-07 14:20   ` Andreas Röhler
2018-05-07 14:26     ` Drew Adams
2018-05-07 17:16       ` Andreas Röhler
2018-05-08  1:46         ` Stefan Monnier
2018-05-08  8:44           ` Andreas Röhler
2018-05-12 22:06             ` Stefan Monnier

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