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Re: How does letf work?
From: |
Emanuel Berg |
Subject: |
Re: How does letf work? |
Date: |
Wed, 29 Jan 2014 01:35:47 +0100 |
User-agent: |
Gnus/5.13 (Gnus v5.13) Emacs/24.3 (gnu/linux) |
Florian Beck <fb@miszellen.de> writes:
> The docstring of letf says: "This is the analogue of
> let', but with generalized variables (in the sense of
> setf') for the PLACEs."
(letf (((cdr test-x) '(a b c d)))
(message "%s" test-x) ; says '(KEY a b c d)
(cdr test-x) ) ; => (a b c d)
(And `... (nth 1 test-x)' => 'a, and so on.)
But:
(letf (((cdr test-x) '(a b c d)))
(message "%s" test-x) ; says '(KEY a b c d)
test-x) ; => '(KEY 1 2 3 4)
`letf' (or `cl-letf') resets the values when it exits:
> On exit, either normally or because of a `throw' or
> error, the PLACEs are set back to their original
> values.
So perhaps this inconsistency is due to the
implementation of that.
--
underground experts united:
http://user.it.uu.se/~embe8573
- Re: How does letf work?,
Emanuel Berg <=