[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

bug#39529: 28.0.50; Metahelp does not contain help text

From: Paul Eggert
Subject: bug#39529: 28.0.50; Metahelp does not contain help text
Date: Wed, 19 Feb 2020 01:00:37 -0800
User-agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.4.1

On 2/18/20 6:34 PM, Pip Cet wrote:
(defun hash-equal (a b)
   (let ((ht (make-hash-table :test 'equal)))
     (puthash a t ht)
     (gethash b ht)))

(hash-equal (point-marker) (point-marker))
(equal (point-marker) (point-marker))

Ah, OK, then I think we're in fundamental agreement about the problem.

However, I don't agree that the Emacs 27-and-earlier approach is tenable, as means that (and (equal a b) (gethash a ht) (not (gethash b ht))) can return t, and similarly unexpected and undesirable behavior elsewhere - even if there are no side effects on hash keys and no cycles in hash key values. For now it should suffice if Emacs handles the case where hash keys don't change and don't have cycles; we can worry about the fancier problems later (if ever).

reply via email to

[Prev in Thread] Current Thread [Next in Thread]