[Top][All Lists]

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

How about text-property-functions using `equal' rather than `eq'?

From: Alan Mackenzie
Subject: How about text-property-functions using `equal' rather than `eq'?
Date: Mon, 4 Feb 2008 20:53:58 +0000
User-agent: Mutt/1.5.9i

Hi, Emacs!

All the built in text property functions which compare properties appear
to use `eq' for the comparison.  Some of these actually say this in
their doc-strings or the pertinent manual page, some of them might
actually say it in both.  ;-(

However, it seems to me that `equal' would be a better comparison.  I am
currently playing with syntax-table text-properties, and some characters
need to have the property set to '(1) (i.e. punctuation).

I would dearly love to use text-property-any to locate such a buffer
position, but unfortunately (eq '(1) '(1)) => nil.  :-(  So I've had to
code up a clumsy equivalent which will certainly be much slower.

Would it not be a good idea to change these functions to use `equal'
instead?  No, it wouldn't be a good idea.

How about providing each of these with an optional extra parameter, the
comparison predicate?  A much better idea!  So we'd have, for example:

  (defun text-property-any (start end prop value &optional object pred)

, with PRED defaulting to `eq'.

Alan Mackenzie (Nuremberg, Germany)

reply via email to

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