Parenthesis and brace matching within RegExps

[pygy]

Modifying regular expressions is a pain, and a part of that pain comes from the fact that editors don't help you with the task, they treat RegExps as if they were strings.

It would be nice, when the cursor is on a parenthesis, a brace or a bracket, to have the editor highlight the one that matches, like vscode does outside RegExps.

[IllusionMH]

Looks like duplicate of #134560

[Z-E-D]

I need this too.

I noticed that braces are highlighted inside strings in .html files, like in this one:
<meta id="vscode-workbench-web-configuration" data-settings="{{WORKBENCH_WEB_CONFIGURATION}}">

And if they could have that, I don't see a reason why Regex parenthesis, a brace or a bracket cannot have the same.

I think this is not a duplicate of the mentioned issue. @pygy is asking for a highlight of the matching braces. The other issue is asking for colorization of braces.

[IllusionMH]

@Z-E-D matching or colorizing brackets still requires you to get proper bracket pairs first. See #134560 (comment) and #134560 (comment).

[Z-E-D]

The numerous web sites with online regexp testers prove that getting the proper bracket pairs is not an issue. Just tried ((?:[)])blah) with:
https://regex101.com/#javascript
https://regexr.com/
https://www.regexpal.com
http://regexpal.com.s3-website-us-east-1.amazonaws.com/

By the way, the colorization of Regex elements is already possible with the proper themes. Just take a look at my screenshot in the #146260 issue.

However, such colorization is not what many expect, since it doesn't have different colors for nested braces, i.e. all braces have the same color even if they are nested. Personally, I don't have a problem with that.

[IllusionMH]

Where did I said "it's impossible" or issue that is hard to solve? Moreover first linked comment provides an option for solution, it's just not something that is available in VS Code and looks like not planned at this moment (based on comments and label).

I just pointed that this requires similar effort. You are right that changing colors based on nesting is more involved that just match braces, however if you have proper pairs then matching can be done and (nested) pairs highlight as next steps as well.

TM Grammars are used to highlight RegExps, but it doesn't look like they are used to match brackets. Would be cool if they were used for RegExps.

[pygy]

Rainbow parens may be nice too, but it's not what I'm requesting here.

This is what I mean, but within RegExps:

[pygy]

I see that tokenizing RegExps is an issue, I'm actually working on a RegExp tokenizer for my own purposes. Hopefully it will be useful here too.

[hediet]

/duplicate #134560

TM Grammars are used to highlight RegExps

Which languages do that?
Maybe #144736 could help to get the requested feature.

[IllusionMH]

@hediet JS/TS and looks like Python, probably other as well, but haven't checked

Screenshots

Note that it's regular part of character set inside of [] and escaped

Python

[hediet]

Let me reopen this to track this idea. I'm curious myself if it would work, but I don't have the time to do it at the moment.

[pygy]

Couldn't RegExps be treated like an embedded language?

Edit: note that, within the RegExp sub-language, character classes themselves must be treated as an embedded language.

[RedCMD]

the problem isn't so much of detecting braces and matching them
but being able to handle malformed regexes, without the bracket matcher going outside the string or just marking everything as broken
as an example: /(/ + variable + /)/. would show up as invalid and possibly destroy the rest of the document

as you can see in my vscode TextMate extension