GNU bug report logs -
#65459
completing-read INITIAL-VALUE unaware of COLLECTION and REQUIRE-MATCH
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> Date: Sat, 26 Aug 2023 08:06:39 +0000
> From: Gregory Heytings <gregory <at> heytings.org>
> cc: Heime <heimeborgia <at> protonmail.com>, Eli Zaretskii <eliz <at> gnu.org>,
> 65459 <at> debbugs.gnu.org
>
>
> >
> > The issue is not "don't use `(n)advice.el`", but "don't modify functions
> > on the sly". And by "functions" this refers to those things stored in
> > the `symbol-function` slot of symbols in the global obarray. This is
> > because code that does `(my-foo ...)` usually expects to execute the
> > code found in `(defun my-foo ...)` and not something else, and readers
> > of that code often make the same assumption, so it can make debugging
> > really nasty.
> >
> > Changing a function with `fset` (or `cl-letf` or `defalias`) is worse
> > than using `advice-add`, for that reason: at least `advice-add` sets up
> > the help system such that `C-h f` will (hopefully) warn you about the
> > presence of an advice.
> >
> > For variables containing functions (such as
> > `minibuffer-default-add-function`), there is no such expectation that
> > calling this function will run some known piece of code, on the
> > contrary: the whole point of the variable is to run difference pieces of
> > code in different contexts, so modifying the function is perfectly OK,
> > regardless whether you do it with `setq` or `add-function`. Here I'd
> > use `add-function` because it's simpler.
> >
>
> Thanks, that clarifies that question! Perhaps a paragraph along those
> lines could be added to "(elisp)Advising Functions"?
Feel free to suggest a clarification for the manual, and thanks in
advance.
This bug report was last modified 1 year and 289 days ago.
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