NAME
Devel::Walk - Walk a complex object or reference.
SYNOPSIS
use Devel::Walk;
use Storable qw( freeze );
# We are looking for things that are unfreezable
sub unfreezable
{
my( $location, $obj ) = @_;
return unless ref $obj
return if eval { local $SIG{__DIE__} = 'DEFAULT'; freeze $obj; 1; };
warn "$location ($obj) is unfreezable";
return 1;
}
walk( $suspect, \&unfreezable, '$obj' );DESCRIPTION
This is actually a very simple module.
walk
walk( $struct, $sub, '$basename' );Recursely walks through $suspect, invoking $sub on each element of each structure. $basename is updated with each recursion to be. Only walks through ARRAY, HASH, SCALAR and REF references. Non-references and other references (CODE, GLOB, IO, etc) are passed over, though $sub is still invoked.
If $basename is empty, '$o' is used as a default.
For each element of the structure, $sub is invoked as follows:
$sub->( $location, $obj );Where $obj is the current element of the structure being looked at and $location is a string that can be used to find the current value. Think of it as the address of the current object, but in perl format. It can be "eval" in perlfunced to a value, provided $basename is available in the current context.
Example : "$o->{top}{second}[3]"
If $sub returns true, recursion will happen on that reference. If $sub returns false, recursion ends. This is the only way to break recursion if your structure contains circular references.
For example, the following will never exit:
my $foo = {};
$foo->{foo} = $foo;
walk( $foo, sub { print "$_[0]\n"; 1 }, '$foo' );SEE ALSO
AUTHOR
Philip Gwyn, <fil-at-pied.nu>
COPYRIGHT AND LICENSE
Copyright (C) 2025 by Philip Gwyn
This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself, either Perl version 5.26.3 or, at your option, any later version of Perl 5 you may have available.