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|
#!/usr/bin/perl
use v5.14;
use warnings;
package BencodeParser;
use base qw( Parser::MGC );
use Syntax::Keyword::Try;
# See also
# https://en.wikipedia.org/wiki/Bencode
sub parse
{
my $self = shift;
$self->any_of(
'parse_int',
'parse_bytestring',
'parse_list',
'parse_dict',
sub { $self->commit; $self->fail( "Expected int, bytestring, list or dict" ) },
);
}
sub parse_int
{
my $self = shift;
$self->expect( 'i' );
my $value = $self->expect( qr/-?\d+/ );
$self->expect( 'e' );
return $value;
}
sub parse_bytestring
{
my $self = shift;
my $len = $self->expect( qr/\d+/ );
$self->expect( ':' );
return $self->take( $len );
}
sub parse_list
{
my $self = shift;
$self->committed_scope_of(
'l',
sub { $self->sequence_of( 'parse' ) },
'e'
);
}
sub parse_dict
{
my $self = shift;
my $kvlist = $self->committed_scope_of(
'd',
sub { $self->sequence_of( 'parse' ) },
'e'
);
return { @$kvlist };
}
use Data::Dumper;
if( !caller ) {
my $parser = __PACKAGE__->new;
while( defined( my $line = <STDIN> ) ) {
try {
my $ret = $parser->from_string( $line );
print Dumper( $ret );
}
catch ( $e ) {
print $e;
}
}
}
1;
|
