use strict; use warnings; use Test::More; use File::Spec; use Class::MOP; BEGIN { require_ok(File::Spec->catfile('examples', 'LazyClass.pod')); } { package BinaryTree; use metaclass ( 'attribute_metaclass' => 'LazyClass::Attribute', 'instance_metaclass' => 'LazyClass::Instance', ); BinaryTree->meta->add_attribute('node' => ( accessor => 'node', init_arg => 'node' )); BinaryTree->meta->add_attribute('left' => ( reader => 'left', default => sub { BinaryTree->new() } )); BinaryTree->meta->add_attribute('right' => ( reader => 'right', default => sub { BinaryTree->new() } )); sub new { my $class = shift; bless $class->meta->new_object(@_) => $class; } } my $root = BinaryTree->new('node' => 0); isa_ok($root, 'BinaryTree'); ok(exists($root->{'node'}), '... node attribute has been initialized yet'); ok(!exists($root->{'left'}), '... left attribute has not been initialized yet'); ok(!exists($root->{'right'}), '... right attribute has not been initialized yet'); isa_ok($root->left, 'BinaryTree'); isa_ok($root->right, 'BinaryTree'); ok(exists($root->{'left'}), '... left attribute has now been initialized'); ok(exists($root->{'right'}), '... right attribute has now been initialized'); ok(!exists($root->left->{'node'}), '... node attribute has not been initialized yet'); ok(!exists($root->left->{'left'}), '... left attribute has not been initialized yet'); ok(!exists($root->left->{'right'}), '... right attribute has not been initialized yet'); ok(!exists($root->right->{'node'}), '... node attribute has not been initialized yet'); ok(!exists($root->right->{'left'}), '... left attribute has not been initialized yet'); ok(!exists($root->right->{'right'}), '... right attribute has not been initialized yet'); is($root->left->node(), undef, '... the left node is uninitialized'); ok(exists($root->left->{'node'}), '... node attribute has now been initialized'); $root->left->node(1); is($root->left->node(), 1, '... the left node == 1'); ok(!exists($root->left->{'left'}), '... left attribute still has not been initialized yet'); ok(!exists($root->left->{'right'}), '... right attribute still has not been initialized yet'); is($root->right->node(), undef, '... the right node is uninitialized'); ok(exists($root->right->{'node'}), '... node attribute has now been initialized'); $root->right->node(2); is($root->right->node(), 2, '... the right node == 1'); ok(!exists($root->right->{'left'}), '... left attribute still has not been initialized yet'); ok(!exists($root->right->{'right'}), '... right attribute still has not been initialized yet'); done_testing;