Hi,

I am facing an issue with using the %item hash for subrules which have a "(?)" repetition specifier (i.e. match one or zero times). As an example, please have a look at the code below: For the below code, I am expecting that I get following output input 

2
0
a

[download]

instead, I get 

input
a

[download]

The documentation states that when we use (s), the value associated with the rule is not a scalar but a reference to a list of scalars. Does this hold for the (?) construct too? If yes, then the below code should work as I dereference the value "$item{range}->[0]".

Thanks and Regards,

Aditya 

use Parse::RecDescent;

my $text = "input [2:0] a";

my $grammar = q {
    rule : 'input' range(?) identifier 
        {
            print $item[1]."\n";
            if (defined @{$item{range}->[0]}) {
                my @arr = @{$item{range}->[0]};
                foreach my $i (@arr) {
                    print $i."\n";
                }
            }
            print $item{identifier};
        }
    range : "[" from_num ":" to_num "]" {$return = [$item{from_num}, $
+item{to_num}]}
    from_num : number {$return = $item{number}}
    to_num : number {$return = $item{number}}
    number : /[0-9][0-9_]*/ 
    identifier : /[a-zA-Z][a-zA-Z_0-9\.]*/
};

my $parser = new Parse::RecDescent($grammar) or die "Bad Grammar";

$parser->rule($text);

[download]

Code tags added by GrandFather

In reply to RecDescent Issue: using item hash with (?) repetition specifier by Anonymous Monk

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