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From: Drew Adams <drew.adams@oracle.com>
To: "Andreas Röhler" <andreas.roehler@easy-emacs.de>,
	"Help Gnu Emacs mailing list" <help-gnu-emacs@gnu.org>
Subject: RE: (copy-marker nil)
Date: Mon, 7 May 2018 07:26:39 -0700 (PDT)	[thread overview]
Message-ID: <0cc6f5df-d980-492c-a6f3-86070a73488c@default> (raw)
In-Reply-To: <1e55da6a-d791-c613-ac9a-5d9bc57f840f@easy-emacs.de>

> > For most functions, passing nil for an &optional parameter is the same
> > as omitting it.
> > If MARKER is not specified, the new marker does not point anywhere.
> 
> It's about the return value.
> A marker pointing nowhere, might it be considered valid?

What do you mean by "valid"?  Yes, it's a marker.  No, it
doesn't have a buffer or position.  The same is true of
other Emacs-Lisp objects, such as overlays: they can exist
without having non-nil values for certain of their properties.

> Expected such returning nil.

Why?  The doc string is pretty clear that it returns a
marker.  And it is clear what happens if arg MARKER is
nil: "the new marker does not point anywhere".



  reply	other threads:[~2018-05-07 14:26 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-05-07  8:19 (copy-marker nil) Andreas Röhler
2018-05-07 13:39 ` 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 [this message]
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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