Method name with non-ASCII characters

[pocke]

Ruby allows you to define a method with non-ASCII characters, but RBS doesn't.

The following code in Ruby is valid.

def こんにちは
end

But RBS raises an error with the following RBS code.

# It is invalid as RBS
class A
  def こんにちは: () -> untyped
end

$ rbs parse test.rbs
parser.y:1373:in `next_token': Unexpected token: こんに�... (RuntimeError)
	from (eval):3:in `_racc_do_parse_c'
	from (eval):3:in `do_parse'
	from parser.y:1108:in `parse_signature'
	from /home/pocke/.rbenv/versions/trunk/lib/ruby/gems/3.0.0/gems/rbs-0.14.0/lib/rbs/cli.rb:739:in `block (2 levels) in run_parse'
	from /home/pocke/.rbenv/versions/trunk/lib/ruby/gems/3.0.0/gems/rbs-0.14.0/lib/rbs/environment_loader.rb:81:in `each_signature'
	from /home/pocke/.rbenv/versions/trunk/lib/ruby/gems/3.0.0/gems/rbs-0.14.0/lib/rbs/cli.rb:738:in `block in run_parse'
	from /home/pocke/.rbenv/versions/trunk/lib/ruby/gems/3.0.0/gems/rbs-0.14.0/lib/rbs/cli.rb:736:in `each'
	from /home/pocke/.rbenv/versions/trunk/lib/ruby/gems/3.0.0/gems/rbs-0.14.0/lib/rbs/cli.rb:736:in `run_parse'
	from /home/pocke/.rbenv/versions/trunk/lib/ruby/gems/3.0.0/gems/rbs-0.14.0/lib/rbs/cli.rb:98:in `run'
	from /home/pocke/.rbenv/versions/trunk/lib/ruby/gems/3.0.0/gems/rbs-0.14.0/exe/rbs:7:in `<top (required)>'
	from /home/pocke/.rbenv/versions/trunk/bin/rbs:23:in `load'
	from /home/pocke/.rbenv/versions/trunk/bin/rbs:23:in `<main>'

I actually define some method in Japanese, so rbs prototype rb generates RBSs with Japanese method name, and they're not valid.
We can define a method with non-ASCII, so I think RBS should allow also.

And, I guess RBS has the same problem for other identifiers, such as class, constants, etc.

[soutaro]

A workaround is quoting the method name.

class A
  def `こんにちは`: () -> void
end

(I know it should parse without quoting because it's incompatible with Ruby.)

[soutaro]

RBS still doesn't allow writing こんにちは as a method name in .rbs files, but it allows writing it with quotes. And RBS::Writer also supports it. (#537)

So, closing this issue for Ruby 3.