-#!/usr/bin/env perl
package Mouse::Meta::Attribute;
use strict;
use warnings;
+require overload;
use Carp 'confess';
-use Scalar::Util 'blessed';
+use Scalar::Util ();
sub new {
my $class = shift;
my %args = @_;
- $args{init_arg} = $args{name}
+ my $name = $args{name};
+
+ $args{init_arg} = $name
unless exists $args{init_arg};
+
$args{is} ||= '';
bless \%args, $class;
}
-sub name { $_[0]->{name} }
-sub class { $_[0]->{class} }
-sub _is_metadata { $_[0]->{is} }
-sub is_required { $_[0]->{required} }
-sub default { $_[0]->{default} }
-sub is_lazy { $_[0]->{lazy} }
-sub predicate { $_[0]->{predicate} }
-sub clearer { $_[0]->{clearer} }
-sub handles { $_[0]->{handles} }
-sub is_weak_ref { $_[0]->{weak_ref} }
-sub init_arg { $_[0]->{init_arg} }
-sub type_constraint { $_[0]->{type_constraint} }
-sub trigger { $_[0]->{trigger} }
-sub builder { $_[0]->{builder} }
-
-sub has_default { exists $_[0]->{default} }
-sub has_predicate { exists $_[0]->{predicate} }
-sub has_clearer { exists $_[0]->{clearer} }
-sub has_handles { exists $_[0]->{handles} }
-sub has_type_constraint { exists $_[0]->{type_constraint} }
-sub has_trigger { exists $_[0]->{trigger} }
-sub has_builder { exists $_[0]->{builder} }
+sub name { $_[0]->{name} }
+sub associated_class { $_[0]->{associated_class} }
+sub _is_metadata { $_[0]->{is} }
+sub is_required { $_[0]->{required} }
+sub default { $_[0]->{default} }
+sub is_lazy { $_[0]->{lazy} }
+sub is_lazy_build { $_[0]->{lazy_build} }
+sub predicate { $_[0]->{predicate} }
+sub clearer { $_[0]->{clearer} }
+sub handles { $_[0]->{handles} }
+sub is_weak_ref { $_[0]->{weak_ref} }
+sub init_arg { $_[0]->{init_arg} }
+sub type_constraint { $_[0]->{type_constraint} }
+sub trigger { $_[0]->{trigger} }
+sub builder { $_[0]->{builder} }
+sub should_auto_deref { $_[0]->{auto_deref} }
+sub should_coerce { $_[0]->{should_coerce} }
+sub find_type_constraint { $_[0]->{find_type_constraint} }
+
+sub has_default { exists $_[0]->{default} }
+sub has_predicate { exists $_[0]->{predicate} }
+sub has_clearer { exists $_[0]->{clearer} }
+sub has_handles { exists $_[0]->{handles} }
+sub has_type_constraint { exists $_[0]->{type_constraint} }
+sub has_trigger { exists $_[0]->{trigger} }
+sub has_builder { exists $_[0]->{builder} }
+
+sub _create_args {
+ $_[0]->{_create_args} = $_[1] if @_ > 1;
+ $_[0]->{_create_args}
+}
+
+sub inlined_name {
+ my $self = shift;
+ my $name = $self->name;
+ my $key = "'" . $name . "'";
+ return $key;
+}
sub generate_accessor {
my $attribute = shift;
- my $name = $attribute->name;
- my $key = $name;
- my $default = $attribute->default;
- my $trigger = $attribute->trigger;
- my $type = $attribute->type_constraint;
- my $constraint = $attribute->find_type_constraint;
- my $builder = $attribute->builder;
+ my $name = $attribute->name;
+ my $default = $attribute->default;
+ my $constraint = $attribute->find_type_constraint;
+ my $builder = $attribute->builder;
+ my $trigger = $attribute->trigger;
+ my $is_weak = $attribute->is_weak_ref;
+ my $should_deref = $attribute->should_auto_deref;
+ my $should_coerce = $attribute->should_coerce;
- my $accessor = 'sub {
- my $self = shift;';
+ my $self = '$_[0]';
+ my $key = $attribute->inlined_name;
+ my $accessor = "sub {\n";
if ($attribute->_is_metadata eq 'rw') {
- $accessor .= 'if (@_) {
- local $_ = $_[0];';
+ $accessor .= 'if (scalar(@_) >= 2) {' . "\n";
+
+ my $value = '$_[1]';
if ($constraint) {
- $accessor .= 'do {
- my $display = defined($_) ? overload::StrVal($_) : "undef";
- Carp::confess("Attribute ($name) does not pass the type constraint because: Validation failed for \'$type\' failed with value $display") unless $constraint->();
- };'
+ $accessor .= 'my $val = ';
+ if ($should_coerce) {
+ $accessor .= 'Mouse::TypeRegistry->typecast_constraints("'.$attribute->associated_class->name.'", $attribute->{find_type_constraint}, $attribute->{type_constraint}, '.$value.');';
+ } else {
+ $accessor .= $value.';';
+ }
+ $accessor .= 'local $_ = $val;';
+ $accessor .= '
+ unless ($constraint->()) {
+ $attribute->verify_type_constraint_error($name, $_, $attribute->type_constraint);
+ }' . "\n";
+ $value = '$val';
}
- $accessor .= '$self->{$key} = $_;';
+ # if there's nothing left to do for the attribute we can return during
+ # this setter
+ $accessor .= 'return ' if !$is_weak && !$trigger && !$should_deref;
- if ($attribute->is_weak_ref) {
- $accessor .= 'Scalar::Util::weaken($self->{$key}) if ref($self->{$key});';
+ $accessor .= $self.'->{'.$key.'} = '.$value.';' . "\n";
+
+ if ($is_weak) {
+ $accessor .= 'Scalar::Util::weaken('.$self.'->{'.$key.'}) if ref('.$self.'->{'.$key.'});' . "\n";
}
if ($trigger) {
- $accessor .= '$trigger->($self, $_, $attribute);';
+ $accessor .= '$trigger->('.$self.', '.$value.', $attribute);' . "\n";
}
- $accessor .= '}';
+ $accessor .= "}\n";
}
else {
- $accessor .= 'confess "Cannot assign a value to a read-only accessor" if @_;';
+ $accessor .= 'confess "Cannot assign a value to a read-only accessor" if scalar(@_) >= 2;' . "\n";
}
if ($attribute->is_lazy) {
- $accessor .= '$self->{$key} = ';
+ $accessor .= $self.'->{'.$key.'} = ';
$accessor .= $attribute->has_builder
- ? '$self->$builder'
- : ref($default) eq 'CODE'
- ? '$default->($self)'
- : '$default';
+ ? $self.'->$builder'
+ : ref($default) eq 'CODE'
+ ? '$default->('.$self.')'
+ : '$default';
+ $accessor .= ' if !exists '.$self.'->{'.$key.'};' . "\n";
+ }
- $accessor .= ' if !exists($self->{$key});';
+ if ($should_deref) {
+ my $type_constraint = $attribute->type_constraint;
+ if (!ref($type_constraint) && $type_constraint eq 'ArrayRef') {
+ $accessor .= 'if (wantarray) {
+ return @{ '.$self.'->{'.$key.'} || [] };
+ }';
+ }
+ else {
+ $accessor .= 'if (wantarray) {
+ return %{ '.$self.'->{'.$key.'} || {} };
+ }';
+ }
}
- $accessor .= 'return $self->{$key}
+ $accessor .= 'return '.$self.'->{'.$key.'};
}';
- return eval $accessor;
+ my $sub = eval $accessor;
+ confess $@ if $@;
+ return $sub;
}
sub generate_predicate {
my $attribute = shift;
- my $key = $attribute->name;
+ my $key = $attribute->inlined_name;
- my $predicate = 'sub { exists($_[0]->{$key}) }';
+ my $predicate = 'sub { exists($_[0]->{'.$key.'}) }';
- return eval $predicate;
+ my $sub = eval $predicate;
+ confess $@ if $@;
+ return $sub;
}
sub generate_clearer {
my $attribute = shift;
- my $key = $attribute->name;
+ my $key = $attribute->inlined_name;
- my $predicate = 'sub { delete($_[0]->{$key}) }';
+ my $clearer = 'sub { delete($_[0]->{'.$key.'}) }';
- return eval $predicate;
+ my $sub = eval $clearer;
+ confess $@ if $@;
+ return $sub;
}
sub generate_handles {
my $method = 'sub {
my $self = shift;
- $self->$reader->$remote_method(@_)
+ $self->'.$reader.'->'.$remote_method.'(@_)
}';
$method_map{$local_method} = eval $method;
+ confess $@ if $@;
}
return \%method_map;
sub create {
my ($self, $class, $name, %args) = @_;
- confess "You cannot have lazy attribute ($name) without specifying a default value for it"
- if $args{lazy} && !exists($args{default}) && !exists($args{builder});
-
- confess "References are not allowed as default values, you must wrap the default of '$name' in a CODE reference (ex: sub { [] } and not [])"
- if ref($args{default})
- && ref($args{default}) ne 'CODE';
+ $args{name} = $name;
+ $args{associated_class} = $class;
+
+ %args = $self->canonicalize_args($name, %args);
+ $self->validate_args($name, \%args);
+
+ $args{should_coerce} = delete $args{coerce}
+ if exists $args{coerce};
+
+ if (exists $args{isa}) {
+ my $type_constraint = delete $args{isa};
+ $type_constraint =~ s/\s//g;
+ my @type_constraints = split /\|/, $type_constraint;
+
+ my $code;
+ my $optimized_constraints = Mouse::TypeRegistry->optimized_constraints;
+ if (@type_constraints == 1) {
+ $code = $optimized_constraints->{$type_constraints[0]} ||
+ sub { Scalar::Util::blessed($_) && Scalar::Util::blessed($_) eq $type_constraints[0] };
+ $args{type_constraint} = $type_constraints[0];
+ } else {
+ my @code_list = map {
+ my $type = $_;
+ $optimized_constraints->{$type} ||
+ sub { Scalar::Util::blessed($_) && Scalar::Util::blessed($_) eq $type }
+ } @type_constraints;
+ $code = sub {
+ for my $code (@code_list) {
+ return 1 if $code->();
+ }
+ return 0;
+ };
+ $args{type_constraint} = \@type_constraints;
+ }
+ $args{find_type_constraint} = $code;
+ }
- $args{type_constraint} = delete $args{isa}
- if exists $args{isa};
+ my $attribute = $self->new(%args);
- my $attribute = $self->new(%args, name => $name, class => $class);
- my $meta = $class->meta;
+ $attribute->_create_args(\%args);
- $meta->add_attribute($attribute);
+ $class->add_attribute($attribute);
# install an accessor
if ($attribute->_is_metadata eq 'rw' || $attribute->_is_metadata eq 'ro') {
my $accessor = $attribute->generate_accessor;
- no strict 'refs';
- *{ $class . '::' . $name } = $accessor;
+ $class->add_method($name => $accessor);
}
for my $method (qw/predicate clearer/) {
if ($attribute->$predicate) {
my $generator = "generate_$method";
my $coderef = $attribute->$generator;
- no strict 'refs';
- *{ $class . '::' . $attribute->$method } = $coderef;
+ $class->add_method($attribute->$method => $coderef);
}
}
if ($attribute->has_handles) {
my $method_map = $attribute->generate_handles;
for my $method_name (keys %$method_map) {
- no strict 'refs';
- *{ $class . '::' . $method_name } = $method_map->{$method_name};
+ $class->add_method($method_name => $method_map->{$method_name});
}
}
return $attribute;
}
-sub find_type_constraint {
+sub canonicalize_args {
my $self = shift;
- my $type = $self->type_constraint;
+ my $name = shift;
+ my %args = @_;
+
+ if ($args{lazy_build}) {
+ $args{lazy} = 1;
+ $args{required} = 1;
+ $args{builder} = "_build_${name}"
+ if !exists($args{builder});
+ if ($name =~ /^_/) {
+ $args{clearer} = "_clear${name}" if !exists($args{clearer});
+ $args{predicate} = "_has${name}" if !exists($args{predicate});
+ }
+ else {
+ $args{clearer} = "clear_${name}" if !exists($args{clearer});
+ $args{predicate} = "has_${name}" if !exists($args{predicate});
+ }
+ }
+
+ return %args;
+}
- return unless $type;
+sub validate_args {
+ my $self = shift;
+ my $name = shift;
+ my $args = shift;
- my $checker = Mouse::TypeRegistry->optimized_constraints->{$type};
- return $checker if $checker;
+ confess "You can not use lazy_build and default for the same attribute ($name)"
+ if $args->{lazy_build} && exists $args->{default};
- return sub { blessed($_) && blessed($_) eq $type };
+ confess "You cannot have lazy attribute ($name) without specifying a default value for it"
+ if $args->{lazy}
+ && !exists($args->{default})
+ && !exists($args->{builder});
+
+ confess "References are not allowed as default values, you must wrap the default of '$name' in a CODE reference (ex: sub { [] } and not [])"
+ if ref($args->{default})
+ && ref($args->{default}) ne 'CODE';
+
+ confess "You cannot auto-dereference without specifying a type constraint on attribute ($name)"
+ if $args->{auto_deref} && !exists($args->{isa});
+
+ confess "You cannot auto-dereference anything other than a ArrayRef or HashRef on attribute ($name)"
+ if $args->{auto_deref}
+ && $args->{isa} ne 'ArrayRef'
+ && $args->{isa} ne 'HashRef';
+
+ if ($args->{trigger}) {
+ if (ref($args->{trigger}) eq 'HASH') {
+ Carp::carp "HASH-based form of trigger has been removed. Only the coderef form of triggers are now supported.";
+ }
+
+ confess "Trigger must be a CODE ref on attribute ($name)"
+ if ref($args->{trigger}) ne 'CODE';
+ }
+
+ return 1;
}
sub verify_type_constraint {
- my $self = shift;
- local $_ = shift;
+ return 1 unless $_[0]->{type_constraint};
- my $type = $self->type_constraint
- or return 1;
- my $constraint = $self->find_type_constraint;
+ local $_ = $_[1];
+ return 1 if $_[0]->{find_type_constraint}->($_);
- return 1 if $constraint->($_);
+ my $self = shift;
+ $self->verify_type_constraint_error($self->name, $_, $self->type_constraint);
+}
- my $name = $self->name;
+sub verify_type_constraint_error {
+ my($self, $name, $value, $type) = @_;
+ $type = ref($type) eq 'ARRAY' ? join '|', @{ $type } : $type;
my $display = defined($_) ? overload::StrVal($_) : 'undef';
Carp::confess("Attribute ($name) does not pass the type constraint because: Validation failed for \'$type\' failed with value $display");
}
+sub coerce_constraint { ## my($self, $value) = @_;
+ my $type = $_[0]->{type_constraint}
+ or return $_[1];
+ return Mouse::TypeRegistry->typecast_constraints($_[0]->associated_class->name, $_[0]->find_type_constraint, $type, $_[1]);
+}
+
sub _canonicalize_handles {
my $self = shift;
my $handles = shift;
}
}
+sub clone_parent {
+ my $self = shift;
+ my $class = shift;
+ my $name = shift;
+ my %args = ($self->get_parent_args($class, $name), @_);
+
+ $self->create($class, $name, %args);
+}
+
+sub get_parent_args {
+ my $self = shift;
+ my $class = shift;
+ my $name = shift;
+
+ for my $super ($class->linearized_isa) {
+ my $super_attr = $super->can("meta") && $super->meta->get_attribute($name)
+ or next;
+ return %{ $super_attr->_create_args };
+ }
+
+ confess "Could not find an attribute by the name of '$name' to inherit from";
+}
+
1;
__END__
=head2 name -> AttributeName
-=head2 class -> OwnerClass
+=head2 associated_class -> OwnerClass
=head2 is_required -> Bool
=head2 has_builder -> Bool
+=head2 is_lazy_build => Bool
+
+=head2 should_auto_deref -> Bool
+
Informational methods.
=head2 generate_accessor -> CODE
Checks that the given value passes this attribute's type constraint. Returns 1
on success, otherwise C<confess>es.
+=head2 canonicalize_args Name, %args -> %args
+
+Canonicalizes some arguments to create. In particular, C<lazy_build> is
+canonicalized into C<lazy>, C<builder>, etc.
+
+=head2 validate_args Name, \%args -> 1 | ERROR
+
+Checks that the arguments to create the attribute (ie those specified by
+C<has>) are valid.
+
+=head2 clone_parent OwnerClass, AttributeName, %args -> Mouse::Meta::Attribute
+
+Creates a new attribute in OwnerClass, inheriting options from parent classes.
+Accessors and helper methods are installed. Some error checking is done.
+
+=head2 get_parent_args OwnerClass, AttributeName -> Hash
+
+Returns the options that the parent class of C<OwnerClass> used for attribute
+C<AttributeName>.
+
=cut
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