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Re: member returns list
From: |
Pascal J. Bourguignon |
Subject: |
Re: member returns list |
Date: |
Sun, 06 Sep 2015 01:39:10 +0200 |
User-agent: |
Gnus/5.13 (Gnus v5.13) Emacs/24.3 (gnu/linux) |
Random832 <random832@fastmail.com> writes:
> Emanuel Berg <embe8573@student.uu.se> writes:
>
>> If we stick to `member' (using `equal') vs. `memq'
>> (using `eq'), this renaming of those:
>>
>> member-equal
>> member-eq
>>
>> would be seen by some people as more consistent than
>> the actual
>>
>> member
>> memq
>
> Why not simply eliminate both and have something like
> (member-test #'eq object list)
>
> Or
> (member-if (lambda (x) (eq object x)) list)?
There were a lot of variants and propositions, amongst all the lisp
dialects. Then starting from 1984, some interested corporations and
institutes invested a lot of money (in form of salaries to detached
employees), to form a standardization commitee and decide on this all
all similar kinds of discrepancies that made porting lisp programs from
one lisp to the other a PITA. They worked hard, for ten years. Then
money was exhausted, so they finalized an ANSI Common Lisp standard in
1994.
Therefore nowadays, you write:
(member element list :test (function eql))
(member element list :test (function equal))
(member element list :test (function equalp))
(member element list :test (function your-own-equivalence-relationship))
or member* in emacs lisp since RMS doesn't want to rejoin the common
community of lispers…
--
__Pascal Bourguignon__ http://www.informatimago.com/
“The factory of the future will have only two employees, a man and a
dog. The man will be there to feed the dog. The dog will be there to
keep the man from touching the equipment.” -- Carl Bass CEO Autodesk
- Re: member returns list, (continued)
- Re: member returns list, Michael Heerdegen, 2015/09/02
- RE: member returns list, Drew Adams, 2015/09/02
- Re: member returns list, Marcin Borkowski, 2015/09/02
- Re: member returns list, Emanuel Berg, 2015/09/03
- Re: member returns list, Marcin Borkowski, 2015/09/04
- Re: member returns list, Emanuel Berg, 2015/09/05
- Re: member returns list, Random832, 2015/09/05
- Re: member returns list, Emanuel Berg, 2015/09/05
- Re: member returns list, Random832, 2015/09/05
- Re: member returns list, Emanuel Berg, 2015/09/05
- Message not available
- Re: member returns list,
Pascal J. Bourguignon <=
- Re: member returns list, Emanuel Berg, 2015/09/05
- Re: member returns list, Robert Thorpe, 2015/09/08
- Re: member returns list, Pascal J. Bourguignon, 2015/09/08
- Re: member returns list, John Mastro, 2015/09/08
- Re: member returns list, Emanuel Berg, 2015/09/09
- Message not available
- Re: member returns list, Pascal J. Bourguignon, 2015/09/06
- Re: member returns list, Emanuel Berg, 2015/09/06
- Message not available
- Re: member returns list, Pascal J. Bourguignon, 2015/09/06
- Re: member returns list, Pascal J. Bourguignon, 2015/09/06
- Re: member returns list, Emanuel Berg, 2015/09/06