Re: Parse::RecDescent grammar definition

[jethro]

Return value (if you don't specify anything through $return) is the value of the last successfully matched items. The information can be found in the documentation in section 'Subrules':

The value associated with a subrule is the value associated with its $return variable (see "Actions" below), or with the last successfully matched item in the subrule match.

The second problem is that your print statement only belongs to the second rule, i.e. if Pre is matched, nothing is done at all. You might check the return value of your call to $p2->Format to see if a production was parsed successfully

[citromatik]

The second problem is that your print statement only belongs to the second rule, i.e. if Pre is matched, nothing is done at all.

Wow, there is something I am not getting here. I would expect %item to have what matches in the rule, so if the rule is "Pre | Post", %item would have either the "Pre" or the "Post" matching part.

Obviously I am getting all this wrong

[jethro]

You are right, %item has either the Pre or Post matching part. But only in one case does it print anything!

Entry      : Pre | Post
  { use Data::Dumper; print Dumper \%item;}

# is equivalent to

Entry : Pre 
Entry : Post
  { use Data::Dumper; print Dumper \%item; }

# is equivalent to

Entry : Post
  { use Data::Dumper; print Dumper \%item; }
Entry : Pre

# is NOT equivalent to

Entry : Pre 
  { use Data::Dumper; print Dumper \%item; }
Entry : Post
 { use Data::Dumper; print Dumper \%item; }

And the last example is what you want