Regex literal syntax

[glennsl]

This adds syntax for regex literals equivalent to the literal syntax in JavaScript. It is effectively just syntax sugar for the %re syntax extension, but opens up the additional possibility of checking the regex syntax during compilation.

The syntax looks like:

let re = /a.*c/mg

which is equivalent to:

let re = %re(`/a.*c/mg`)

and compiles to:

var re = /a.*c/mg;

Closes #6287

[bloodyowl]

I think it might be worth adding an attribute to the expression not to incorrectly print escaped regexp as an unescaped one

[glennsl]

I think it might be worth adding an attribute to the expression not to incorrectly print escaped regexp as an unescaped one

I`m not sure I follow. Can you give an example?

[glennsl]

Tests passing! 🥳

I'm sure the code quality could be improved, and we could add validation of the internal regex syntax either before or after merging this.

[cknitt]

@glennsl Could you add a CHANGELOG entry?

@IwanKaramazow Good to go?

[IwanKaramazow]

@cknitt I'll do one last pass over the next few days to see if there aren't any edge cases.

[cknitt]

@cknitt I'll do one last pass over the next few days to see if there aren't any edge cases.

Ping @IwanKaramazow 🙂

[IwanKaramazow]

Ah, yes, will do a review this weekend!