number.pl

use 5.010;
use strict;
use warnings;

use Data::Dumper;

use Marpa::R2;

my $g = Marpa::R2::Scanless::G->new( { 
    bless_package => 'main',
    source => \(<<'END_OF_SOURCE'),
:default ::= action => [name, values]
lexeme default = action => [name, value]

Numbers ::= Number+

Number ::= '0b' BinDigits | '0x' HexDigits 

HexDigits ::= [\dA-Fa-f]+
BinDigits ::= [01]+

:discard ~ whitespace
whitespace ~ [\s]+
END_OF_SOURCE
} );

my $input = <<EOI;
0b0101
0x0f01
EOI

my $r = Marpa::R2::Scanless::R->new( { grammar => $g } );
$r->read(\$input);
say Dumper ${ $r->value() };

Output:

$VAR1 = [
          'Numbers',
          [
            'Number',
            '0b',
            [
              'BinDigits',
              '0',
              '1',
              '0',
              '1'
            ]
          ],
          [
            'Number',
            '0x',
            [
              'HexDigits',
              '0',
              'f',
              '0',
              '1'
            ]
          ]
        ];