Re: Looking at function

[Juri Linkov]

>> 1. Replace ‘looking-at’ with a call to the search function,
>>    but keep it at point by prepending ‘\\=’ to the regexp.
>>    Can it break a complex regexp?
>
> I can't see why.  Of course, you want to use \\=\\(?:...\\) but
> that should be reliable.

I confirm that \\= works reliable, but discovered that not all
search functions can be used instead of looking-at
in isearch-search-and-update.  When calling a search function
that searches through the minibuffer history in the minibuffer,
it tries to find \\= in every minibuffer history item and
eventually messes up the minibuffer contents.
So looking-at can't be replaced in isearch-search-and-update.

There is no problem with replacing looking-at with searching \\=
in perform-replace since it uses the default search function
that can be overridden by replace-re-search-function, and
no one sets replace-re-search-function to a function that
tries to do replacements through all minibuffer history items.