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From: Michael Heerdegen <michael_heerdegen@web.de>
To: Stefan Monnier via Users list for the GNU Emacs text editor
	<help-gnu-emacs@gnu.org>
Cc: Stefan Monnier <monnier@iro.umontreal.ca>
Subject: Re: Generic functions: Specializers like `or' or `memq'?
Date: Sat, 06 Nov 2021 23:32:31 +0100	[thread overview]
Message-ID: <878ry0nce8.fsf@web.de> (raw)
In-Reply-To: <jwvmtmkbtvq.fsf-monnier+emacs@gnu.org> (Stefan Monnier via Users list for the's message of "Wed, 03 Nov 2021 21:31:50 -0400")

Stefan Monnier via Users list for the GNU Emacs text editor
<help-gnu-emacs@gnu.org> writes:

> The main problem is one of ordering between different methods when
> several methods are applicable.
> [ `cl-generic.el` solves this problem by forcing the generalizer to
>   come with a priority (a number), which makes the ordering "trivial"
>   for `cl-generic.el` but it can be hard to choose the right priority
>   to use when defining a new specializer/generalizer.  ]

I don't see this.  How would an `or' or `memql' specializer be different
from implementing the method several times for each alternative using
the same body?  There would be a problem only if the domains of the
specializers would not be disjoint.  But that can already happen now.  I
don't see why we would make the situation worse, unless the programmer
does really strange things like listing the same (sub)specializer in
mutliple `or' specializers.  This could be warned about.

I guess I have missed something.

Michael.



  parent reply	other threads:[~2021-11-06 22:32 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-11-03 17:17 Generic functions: Specializers like `or' or `memq'? Michael Heerdegen
2021-11-03 18:21 ` Philip Kaludercic
2021-11-03 21:10   ` Michael Heerdegen
2021-11-03 21:32     ` Eric Abrahamsen
2021-11-03 23:19       ` Michael Heerdegen
2021-11-03 23:38         ` Emanuel Berg via Users list for the GNU Emacs text editor
2021-11-04  0:26           ` Michael Heerdegen
2021-11-04  1:31       ` Stefan Monnier via Users list for the GNU Emacs text editor
2021-11-04  2:34         ` Stefan Monnier via Users list for the GNU Emacs text editor
2021-11-04  4:01           ` Emanuel Berg via Users list for the GNU Emacs text editor
2021-11-06 22:32         ` Michael Heerdegen [this message]
2021-11-06 23:36           ` Stefan Monnier via Users list for the GNU Emacs text editor
2021-11-07  1:48             ` Michael Heerdegen
2021-11-21 19:43               ` Stefan Monnier via Users list for the GNU Emacs text editor
2021-11-23  8:16                 ` Michael Heerdegen
  -- strict thread matches above, loose matches on Subject: below --
2021-11-04 17:31 Eric Abrahamsen
2021-11-05 21:17 ` Stefan Monnier via Users list for the GNU Emacs text editor
2021-11-05 21:36   ` Emanuel Berg via Users list for the GNU Emacs text editor
2021-11-06 23:29     ` Stefan Monnier via Users list for the GNU Emacs text editor
2021-11-06 23:52       ` Emanuel Berg via Users list for the GNU Emacs text editor

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