(Where I had to manually test something, I used godbolt. (Except for Ruby, which I tested locally because Godbolt doesn't permit passing command-line arguments to ruby
. There's a box for it, but it gets parsed as a filename.) The characters I tested were é
and 𐐀
, and I only tried the latest x86_64/amd64 version of the compiler/interpreter if there were multiple versions to choose from.)
-
Unicode provides a recommendation for identifier syntax in Annex 31, defining the properties
XID_Start
andXID_Continue
(and alsoID_Start
andID_Continue
, but these seem to be less used). -
The C standards are paywalled, but according to cppreference.com, from C99 on, identifiers can contain
\u
and\U
escape sequences, and implementations may accept actual Unicode characters. That lasts until the current draft version ("C23", although it isn't