Remove the Emacs Lisp specific escaping test.

[Fanael]

In fact, nuke the infrastructure altogether.

Parens as characters without a backslash are nasty and they really should never be used:

• This syntax is discouraged by the GNU Emacs Lisp Reference Manual.
• They confuse many a minor mode, such as show-paren-mode.
• The way we currently handle them partially solves the problem, but is a hack made of eldritch magic, implemented by gluing special cases together hoping they'll work...
• ...but it doesn't really work, and it's pretty easy to get mishighlighted delimiters anyway.
• They confuse the Emacs Lisp indentation engine. Really.
• It's the major mode's job to set the syntax-table properties on individual characters.

Because of these reasons, it's just easier to drop this misfeature and rely on people to start using ?\( instead.

And because the whole point of rainbow-delimiters-escaped-char-predicate-list is to allow for this, nuke it too. It was never really a documented part of the API.

---

@purcell (and others who want this test still there): I'm sorry. I understand that you want it. But the current hack doesn't really work. Try deleting the backslash in this code:

(lorem '(?\[ ipsum))

(defun lorem (ipsum)
  (dolor)
  (sit amet))

The ) closing the list will be mismatched, and everything below and including the defun will have wrong depth.

If you want to have a truly working handling of unbackslashed parens as characters, you should probably try and contribute to the EVIL-ignore-blacklisted-delims-altogether branch. The approach used there has at least some chance of getting this right, for some values of "right".

Or, convince me that the broken mess used by rainbow-delimiters right now is better than a similarly broken non-mess. To be frank, I suggest you invest your time into making #1 mergable instead of trying to convince me, as it's much easier.

[purcell]

I'm sorry. I understand that you want it.

Really not a problem for me. I'd rather the code be clean, maintainable and performant than slavishly try to handle every possible crazy edge case.

[Fanael]

Yet a week ago you said:

I'm probably the wrong person to ask, because IIRC I was the one who complained about that special case not being handled. At this stage I guess I don't care too much, but it would be a shame if parens got wrongly highlighted as mismatched in a source file which contains ?) or ?(.

But I guess you changed your mind.

I'd rather the code be clean, maintainable and performant than slavishly try to handle every possible crazy edge case.

Anyway, it's not important now that this hack got nuked. I wonder how many hacks are left.

[purcell]

That's not a contradiction. You can read it as: it would be a shame if that case didn't work, but ultimately I place greater value on clean code than on keeping that case working. :-)

[Wilfred]

@Fanael could this be fixed in Emacs itself? If so, what would need to change?

[Fanael]

I'm not the best person to ask this question, because I don't really know a lot about Emacs, but I imagine that

It's the major mode's job to set the syntax-table properties on individual characters.

is probably the easiest way to deal with this. It should be possible, and likely necessary, to implement this as a third-party minor mode, as an interim solution until it's fixed in Emacs itself, thanks to the amount of bureaucracy driving Emacs development.

[purcell]

It should be possible, and likely necessary, to implement this as a third-party minor mode, as an interim solution until it's fixed in Emacs itself, thanks to the amount of bureaucracy driving Emacs development.

You'd be surprised how quickly fixes can be put in place in the Emacs core thanks to the involvement of people like @dgutov in recent years. But yes, that still helps only users of Emacs HEAD until the next version gets released.

[Fanael]

You'd be surprised how quickly fixes can be put in place in the Emacs core thanks to the involvement of people like @dgutov in recent years.

Only if the fix is written by somebody who's already signed the CLA selling one's soul to Stallman. I haven't, so if I wanted to fix something, legalese alone would take a couple of months.

[dgutov]

Regarding patches, the first 15 lines are "free".

But you can submit a bug report instead though, right?

[Fanael]

But you can submit a bug report instead though, right?

Yes, and that's what I do: so far, I reported all Emacs bugs affecting me. All zero of them.

[purcell]

Hey @Wilfred, would you perhaps go ahead and M-x report-emacs-bug this?