Regular Expression finds about typescript HOT 4 OPEN

I expect all of the errors not related to --target are a result of regular expressions that are allowed per Annex B.

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IMO, all of the "Octal escape sequences are not allowed" and "A decimal escape must refer to an existent capturing group" are probably indications of actual errors in user code. They're allowed in Annex B, but the user likely intended to use them as a backreference to a capture group and that's not how Annex B would treat them.

All of the "A character class range must not be bounded by another character class" errors are probably fine and shouldn't be reported. Annex B allows them and most users wrote something like [\w-.] or the like thinking it meant "word characters, -, and .", which is how Annex B treats them.

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Ah, I did once mentioned this on my PR and thought it was fine since Ryan reacted on my comment.
#55600 (comment)
I am fine with weakening the grammar, however keep in mind that we can’t guarantee everything runs on engines with Annex B support though I understand that this is mostly the case. IMHO another compiler option is the only realistic way to solve this, unfortunately.

from typescript.

IMO, all of the "Octal escape sequences are not allowed" and "A decimal escape must refer to an existent capturing group" are probably indications of actual errors in user code.

Yes, I actually thought that there is a consensus on not allowing any octal escapes anywhere per #53198 😅

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