my-rule-grammar.p6

#!/usr/bin/env perl6

use v6;

grammar MyRule {
  token TOP {
    [<my-rule> \n+]*
  }

  proto token my-rule {*}

  token my-rule:sym<a-or-b> {
    'a' | 'b'
  }
}

my $contents = slurp;

if MyRule.parse($contents) {
  say "parsed";
} else {
  say "noparse";
}