* Why is this thing (isearch-search-fun) coded like this?
@ 2015-12-07 21:12 Alan Mackenzie
2015-12-07 21:20 ` John Wiegley
2015-12-07 21:32 ` Artur Malabarba
0 siblings, 2 replies; 3+ messages in thread
From: Alan Mackenzie @ 2015-12-07 21:12 UTC (permalink / raw)
To: emacs-devel
Hello, Emacs.
I'm absolutely stumped.
`isearch-search-fun', when called, returns a function "to use" for
searching. To do this, it funcalls .....
.... `isearch-search-fun-default'. This returns a constant lambda form.
CONSTANT LAMBDA FORMS ARE NOT EASY TO INSTRUMENT FOR EDEBUG!!!!
As an alternative, isearch-search-fun-default could simply return a
named function. Even better, such a named function could simply be, and
be returned directly from `isearch-search-fun' without all the
superfluous funcalling.
Or am I missing something here?
All this "is a function which returns a function by funcalling a
function which returns a constant lambda form" has exhausted any desire
I had to debug my problem to a finish.
I'm tempted to rip out a lot of this stuff from Isearch to be able to
debug it. Will I regret it if I do?
--
Alan Mackenzie (Nuremberg, Germany).
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: Why is this thing (isearch-search-fun) coded like this?
2015-12-07 21:12 Why is this thing (isearch-search-fun) coded like this? Alan Mackenzie
@ 2015-12-07 21:20 ` John Wiegley
2015-12-07 21:32 ` Artur Malabarba
1 sibling, 0 replies; 3+ messages in thread
From: John Wiegley @ 2015-12-07 21:20 UTC (permalink / raw)
To: Alan Mackenzie; +Cc: emacs-devel
>>>>> Alan Mackenzie <acm@muc.de> writes:
> As an alternative, isearch-search-fun-default could simply return a named
> function. Even better, such a named function could simply be, and be
> returned directly from `isearch-search-fun' without all the superfluous
> funcalling.
It does look like it should just return a function symbol, rather than a
lambda. It's not even a closure.
--
John Wiegley GPG fingerprint = 4710 CF98 AF9B 327B B80F
http://newartisans.com 60E1 46C4 BD1A 7AC1 4BA2
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: Why is this thing (isearch-search-fun) coded like this?
2015-12-07 21:12 Why is this thing (isearch-search-fun) coded like this? Alan Mackenzie
2015-12-07 21:20 ` John Wiegley
@ 2015-12-07 21:32 ` Artur Malabarba
1 sibling, 0 replies; 3+ messages in thread
From: Artur Malabarba @ 2015-12-07 21:32 UTC (permalink / raw)
To: Alan Mackenzie; +Cc: emacs-devel
2015-12-07 21:12 GMT+00:00 Alan Mackenzie <acm@muc.de>:
> CONSTANT LAMBDA FORMS ARE NOT EASY TO INSTRUMENT FOR EDEBUG!!!!
I know there's an extra layer of indirection, but I've always been
able to edebug it just fine.
> As an alternative, isearch-search-fun-default could simply return a
> named function. Even better, such a named function could simply be, and
> be returned directly from `isearch-search-fun' without all the
> superfluous funcalling.
>
> Or am I missing something here?
IIRC, isearch-search-fun-default didn't use to return a constant
lambda. Instead, it used to return a different lambda depending on
some parameters.
We reached the current state as a result of some recent refactorings.
I agree it would be good to remove this layer of indirection.
> I'm tempted to rip out a lot of this stuff from Isearch to be able to
> debug it. Will I regret it if I do?
You won't regret it if you do it right:
1. Define a function for that lambda.
2. Set the default value of isearch-search-fun to be this function's name.
3. Make isearch-search-fun-default return the function's name, and
mark it obsolete.
^ permalink raw reply [flat|nested] 3+ messages in thread
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2015-12-07 21:12 Why is this thing (isearch-search-fun) coded like this? Alan Mackenzie
2015-12-07 21:20 ` John Wiegley
2015-12-07 21:32 ` Artur Malabarba
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