Parsing a C++ function declaration with Perl 6 grammar

Question

I wrote a Perl 6 grammar to parse a C++ function. My final goal would be to parse an entire header. The aim is not to correct C++ syntax errors, but to parse valid C++.

Do you have some advice or improvements?

#!/usr/bin/env perl6
grammar FUNCTION {
 token TOP { [ <attr> \s+ ]? <type> [ \s* <type_mod> ]? 
 (\s+) <fname> (\s*) "("
 (\s*) [<parameter> [ "," (\s*) <parameter> ]* ]? (\s*) 
 ')'(\s*) ';' 
 }
 token name { \w+ }
 token namespace { [ "::" ]? [ <name> "::" ]* }
 token attr { <name> }
 token type { <namespace>? <name> }
 token type_mod { [ \*|\& ]+ }
 token fname { <name> }
 token variable { <name> }
 token parameter { <type> [\s* <type_mod> ]? \s+ <variable> }
}
my $str = "const ::one::std::string ** ma1n( int&& i, two::std::string va1e_ );";
my $parsed = FUNCTION.parse($str);
say $parsed;

Answer 1

I'd expect to see many more tests of any program that addresses a problem as gnarly as parsing a C++ declaration.

Choosing a couple I've recently had cause to write (on Stack Overflow), I would immediately add

• void (SENDER::*get_func())(double, double);
  

  (from Passing pointers to member function as returned values to QObject::connect())

• constexpr std::size_t len(const T(&)[length]);
  

  (from Differentiate between array and pointer as function parameter)

Neither of these succeeded when I tried them.

• papagaga: I've no way to test it right there but I believe it also lacks noexcept support