Commit 33e9d8af79c94864e0828770bcfb5f6dd4aa1cfb - libdata-visitor-perl

Handle circular refs properly Yuval Kogman 18 years ago

2 changed file(s) with 33 addition(s) and 0 deletion(s). Raw diff Collapse all Expand all

-0

lib/Data/Visitor.pm less more

6	6	use warnings;
7	7
8	8	use Scalar::Util ();
	9	use overload ();
9	10
10	11	our $VERSION = "0.01";
11	12
12	13	sub visit {
13	14	my ( $self, $data ) = @_;
	15
	16	local $self->{_seen} = ($self->{_seen} \|\| {});
	17	return $data if ref $data and $self->{_seen}{ overload::StrVal( $data ) }++;
14	18
15	19	if ( Scalar::Util::blessed( $data ) ) {
16	20	return $self->visit_object( $data );

+29

-0

t/circular_refs.t less more

	0	#!/usr/bin/perl
	1
	2	use strict;
	3	use warnings;
	4
	5	use Test::More tests => 3;
	6
	7
	8	my $m; use ok $m = "Data::Visitor";
	9
	10	my $structure = {
	11	foo => {
	12	bar => undef,
	13	},
	14	};
	15
	16	$structure->{foo}{bar} = $structure;
	17
	18	my $o = $m->new;
	19
	20	{
	21	alarm 1;
	22	$o->visit( $structure );
	23	alarm 0;
	24	pass( "circular structures don't cause an endless loop" );
	25	}
	26
	27	is_deeply( $o->visit( $structure ), $structure, "Structure recreated" );
	28