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From: | Tino Calancha |
Subject: | bug#27584: 26.0.50; alist-get: Add optional arg TESTFN |
Date: | Mon, 10 Jul 2017 22:02:34 +0900 (JST) |
User-agent: | Alpine 2.20 (DEB 67 2015-01-07) |
On Mon, 10 Jul 2017, Michael Heerdegen wrote:
Tino Calancha <tino.calancha@gmail.com> writes:I rewrote it as follows: (declare (compiler-macro (lambda (form) (pcase pred (''eq `(assq ,key ,alist)) ((or ''equal 'nil) `(assoc ,key ,alist)) ((and (guard (macroexp-const-p key)) ''eql) (if (floatp key) `(assoc ,key ,alist) `(assq ,key ,alist))) (t form)))))Is this a good idea in general? PRED could also be function-quoted, or a variable bound to `eq'. And KEY could be an expression that evaluates to a float. That would fail the `floatp' test.
Well, this code is now in the 'Limbo', because we are thinking to use the Nico solution (`assoc' having an optional arg PRED). That said, its fun to discuss about it.You know, this compiler macro is inspired in the one used by `cl-assoc' i.e., `cl--compiler-macro-assoc'. If you find a problem
on it, then the same problem might arise in `cl-assoc' :-S
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