Listing 5

#grammar Minilanguage {
    rule start    { START | BEGIN }
    rule command  { help | showversion | quit }
    rule commands { [<command>]+ }
    rule stop     { STOP | END }
    token prog {
                <start>
                <commands>
                <stop>
               }
#}
# verarbeitet das Match-Objekt
sub execute (Match $prog) {
  say "Running...";
  my $i = 0;
  for split( rx/\s+/, $prog<prog><commands> ) -> $cmd
  {
    say " { $i++}: $cmd";
  }
  say "Done.";
}
my $example_prog = 'START showversion quit STOP';
my $parsed       = $example_prog ~~ /<prog>/;
execute($parsed) if $parsed;
say $parsed.perl;  # dump Match objekt

Regeln definieren eine einfache Grammatik