Named subpatterns in regex

[malmaud]

Unless I'm missing something, RegexMatch objects don't provide a way to access named captures by name, but only by position; eg

match(r"(?P<hour>\d\d):(?P<minute>\d\d)", "Time is 12:45")
RegexMatch("12:45", 1="12", 2="45")

[kmsquire]

Related: #1448 (somewhat related: #1820, #1289)

Regex's could use some love if someone wants to put in the time.

[stevengj]

Basically, this would involve wrapping the pcre2_substring_copy_byname function in PCRE? Couldn't we just implement a getindex(::RegexMatch, key::String) method that exposes this, so you could do m = match(...); m["hour"]?

[tkelman]

We aren't binding PCRE2 yet, we're still on 8.36. We might need to upgrade to get some newer functionality. Regexes should probably be updated to return Nullables if someone wants to dig into that code.

[malmaud]

Implemented by #11566