-#!/usr/bin/env perl
package Mouse::Meta::Role;
use strict;
use warnings;
-do {
- my %METACLASS_CACHE;
+use Mouse::Util qw(not_supported english_list);
+use Mouse::Meta::Module;
- # because Mouse doesn't introspect existing classes, we're forced to
- # only pay attention to other Mouse classes
- sub _metaclass_cache {
- my $class = shift;
- my $name = shift;
- return $METACLASS_CACHE{$name};
- }
+use base qw(Mouse::Meta::Module);
- sub initialize {
- my $class = shift;
- my $name = shift;
- $METACLASS_CACHE{$name} = $class->new(name => $name)
- if !exists($METACLASS_CACHE{$name});
- return $METACLASS_CACHE{$name};
- }
-};
+sub method_metaclass(){ 'Mouse::Meta::Role::Method' } # required for get_method()
-sub new {
+sub _construct_meta {
my $class = shift;
+
my %args = @_;
- bless \%args, $class;
+ $args{methods} ||= {};
+ $args{attributes} ||= {};
+ $args{required_methods} ||= [];
+ $args{roles} ||= [];
+
+# return Mouse::Meta::Class->initialize($class)->new_object(%args)
+# if $class ne __PACKAGE__;
+
+ return bless \%args, ref($class) || $class;
+}
+
+sub create_anon_role{
+ my $self = shift;
+ return $self->create(undef, @_);
+}
+
+sub is_anon_role{
+ return exists $_[0]->{anon_serial_id};
+}
+
+sub get_roles { $_[0]->{roles} }
+
+sub get_required_method_list{
+ return @{ $_[0]->{required_methods} };
+}
+
+sub add_required_methods {
+ my($self, @methods) = @_;
+ push @{$self->{required_methods}}, @methods;
+}
+
+sub requires_method {
+ my($self, $name) = @_;
+ return scalar( grep{ $_ eq $name } @{ $self->{required_methods} } ) != 0;
+}
+
+sub add_attribute {
+ my $self = shift;
+ my $name = shift;
+
+ $self->{attributes}->{$name} = (@_ == 1) ? $_[0] : { @_ };
}
-sub name { $_[0]->{name} }
+sub _canonicalize_apply_args{
+ my($self, $applicant, %args) = @_;
+
+ if($applicant->isa('Mouse::Meta::Class')){
+ $args{_to} = 'class';
+ }
+ elsif($applicant->isa('Mouse::Meta::Role')){
+ $args{_to} = 'role';
+ }
+ else{
+ $args{_to} = 'instance';
+
+ not_supported 'Application::ToInstance';
+ }
+
+ if($args{alias} && !exists $args{-alias}){
+ $args{-alias} = $args{alias};
+ }
+ if($args{excludes} && !exists $args{-excludes}){
+ $args{-excludes} = $args{excludes};
+ }
+
+ if(my $excludes = $args{-excludes}){
+ $args{-excludes} = {}; # replace with a hash ref
+ if(ref $excludes){
+ %{$args{-excludes}} = (map{ $_ => undef } @{$excludes});
+ }
+ else{
+ $args{-excludes}{$excludes} = undef;
+ }
+ }
+
+ return \%args;
+}
+
+sub _check_required_methods{
+ my($role, $class, $args, @other_roles) = @_;
+
+ if($args->{_to} eq 'class'){
+ my $class_name = $class->name;
+ my $role_name = $role->name;
+ my @missing;
+ foreach my $method_name(@{$role->{required_methods}}){
+ if(!$class_name->can($method_name)){
+ my $has_method = 0;
+
+ foreach my $another_role_spec(@other_roles){
+ my $another_role_name = $another_role_spec->[0];
+ if($role_name ne $another_role_name && $another_role_name->can($method_name)){
+ $has_method = 1;
+ last;
+ }
+ }
+
+ push @missing, $method_name if !$has_method;
+ }
+ }
+ if(@missing){
+ $class->throw_error("'$role_name' requires the "
+ . (@missing == 1 ? 'method' : 'methods')
+ . " "
+ . english_list(map{ sprintf q{'%s'}, $_ } @missing)
+ . " to be implemented by '$class_name'");
+ }
+ }
+ elsif($args->{_to} eq 'role'){
+ # apply role($role) to role($class)
+ foreach my $method_name($role->get_required_method_list){
+ next if $class->has_method($method_name); # already has it
+ $class->add_required_methods($method_name);
+ }
+ }
+
+ return;
+}
+
+sub _apply_methods{
+ my($role, $class, $args) = @_;
+
+ my $role_name = $role->name;
+ my $class_name = $class->name;
+
+ my $alias = $args->{-alias};
+ my $excludes = $args->{-excludes};
+
+ foreach my $method_name($role->get_method_list){
+ next if $method_name eq 'meta';
+
+ my $code = $role_name->can($method_name);
+
+ if(!exists $excludes->{$method_name}){
+ if(!$class->has_method($method_name)){
+ $class->add_method($method_name => $code);
+ }
+ }
+
+ if($alias && $alias->{$method_name}){
+ my $dstname = $alias->{$method_name};
+
+ my $dstcode = do{ no strict 'refs'; *{$class_name . '::' . $dstname}{CODE} };
+
+ if(defined($dstcode) && $dstcode != $code){
+ $class->throw_error("Cannot create a method alias if a local method of the same name exists");
+ }
+ else{
+ $class->add_method($dstname => $code);
+ }
+ }
+ }
+
+ return;
+}
+
+sub _apply_attributes{
+ my($role, $class, $args) = @_;
+
+ if ($args->{_to} eq 'class') {
+ # apply role to class
+ for my $attr_name ($role->get_attribute_list) {
+ next if $class->has_attribute($attr_name);
+
+ my $spec = $role->get_attribute($attr_name);
+
+ $class->add_attribute($attr_name => %{$spec});
+ }
+ }
+ elsif($args->{_to} eq 'role'){
+ # apply role to role
+ for my $attr_name ($role->get_attribute_list) {
+ next if $class->has_attribute($attr_name);
+
+ my $spec = $role->get_attribute($attr_name);
+ $class->add_attribute($attr_name => $spec);
+ }
+ }
+
+ return;
+}
+
+sub _apply_modifiers{
+ my($role, $class, $args) = @_;
+
+ for my $modifier_type (qw/override before around after/) {
+ my $add_modifier = "add_${modifier_type}_method_modifier";
+ my $modifiers = $role->{"${modifier_type}_method_modifiers"};
+
+ while(my($method_name, $modifier_codes) = each %{$modifiers}){
+ foreach my $code(ref($modifier_codes) eq 'ARRAY' ? @{$modifier_codes} : $modifier_codes){
+ $class->$add_modifier($method_name => $code);
+ }
+ }
+ }
+ return;
+}
+
+sub _append_roles{
+ my($role, $class, $args) = @_;
+
+ my $roles = ($args->{_to} eq 'class') ? $class->roles : $class->get_roles;
+
+ foreach my $r($role, @{$role->get_roles}){
+ if(!$class->does_role($r->name)){
+ push @{$roles}, $r;
+ }
+ }
+ return;
+}
+
+# Moose uses Application::ToInstance, Application::ToClass, Application::ToRole
+sub apply {
+ my $self = shift;
+ my $applicant = shift;
+
+ my $args = $self->_canonicalize_apply_args($applicant, @_);
+
+ $self->_check_required_methods($applicant, $args);
+ $self->_apply_methods($applicant, $args);
+ $self->_apply_attributes($applicant, $args);
+ $self->_apply_modifiers($applicant, $args);
+ $self->_append_roles($applicant, $args);
+ return;
+}
+
+sub combine_apply {
+ my(undef, $class, @roles) = @_;
+
+ if($class->isa('Mouse::Object')){
+ not_supported 'Application::ToInstance';
+ }
+
+ # check conflicting
+ my %method_provided;
+ my @method_conflicts;
+ my %attr_provided;
+ my %override_provided;
+
+ foreach my $role_spec (@roles) {
+ my $role = $role_spec->[0]->meta;
+ my $role_name = $role->name;
+
+ # methods
+ foreach my $method_name($role->get_method_list){
+ next if $class->has_method($method_name); # manually resolved
+
+ my $code = do{ no strict 'refs'; \&{ $role_name . '::' . $method_name } };
+
+ my $c = $method_provided{$method_name};
+
+ if($c && $c->[0] != $code){
+ push @{$c}, $role;
+ push @method_conflicts, $c;
+ }
+ else{
+ $method_provided{$method_name} = [$code, $method_name, $role];
+ }
+ }
+
+ # attributes
+ foreach my $attr_name($role->get_attribute_list){
+ my $attr = $role->get_attribute($attr_name);
+ my $c = $attr_provided{$attr_name};
+ if($c && $c != $attr){
+ $class->throw_error("We have encountered an attribute conflict with '$attr_name' "
+ . "during composition. This is fatal error and cannot be disambiguated.")
+ }
+ else{
+ $attr_provided{$attr_name} = $attr;
+ }
+ }
+
+ # override modifiers
+ foreach my $method_name($role->get_method_modifier_list('override')){
+ my $override = $role->get_override_method_modifier($method_name);
+ my $c = $override_provided{$method_name};
+ if($c && $c != $override){
+ $class->throw_error( "We have encountered an 'override' method conflict with '$method_name' during "
+ . "composition (Two 'override' methods of the same name encountered). "
+ . "This is fatal error.")
+ }
+ else{
+ $override_provided{$method_name} = $override;
+ }
+ }
+ }
+ if(@method_conflicts){
+ my $error;
+
+ if(@method_conflicts == 1){
+ my($code, $method_name, @roles) = @{$method_conflicts[0]};
+ $class->throw_error(
+ sprintf q{Due to a method name conflict in roles %s, the method '%s' must be implemented or excluded by '%s'},
+ english_list(map{ sprintf q{'%s'}, $_->name } @roles), $method_name, $class->name
+ );
+ }
+ else{
+ @method_conflicts = sort { $a->[0] cmp $b->[0] } @method_conflicts; # to avoid hash-ordering bugs
+ my $methods = english_list(map{ sprintf q{'%s'}, $_->[1] } @method_conflicts);
+ my $roles = english_list(
+ map{ sprintf q{'%s'}, $_->name }
+ map{ my($code, $method_name, @roles) = @{$_}; @roles } @method_conflicts
+ );
+
+ $class->throw_error(
+ sprintf q{Due to method name conflicts in roles %s, the methods %s must be implemented or excluded by '%s'},
+ $roles, $methods, $class->name
+ );
+ }
+ }
+
+ foreach my $role_spec (@roles) {
+ my($role_name, $args) = @{$role_spec};
+
+ my $role = $role_name->meta;
+
+ $args = $role->_canonicalize_apply_args($class, %{$args});
+
+ $role->_check_required_methods($class, $args, @roles);
+ $role->_apply_methods($class, $args);
+ $role->_apply_attributes($class, $args);
+ $role->_apply_modifiers($class, $args);
+ $role->_append_roles($class, $args);
+ }
+ return;
+}
+
+for my $modifier_type (qw/before after around/) {
+
+ my $modifier = "${modifier_type}_method_modifiers";
+ my $add_method_modifier = sub {
+ my ($self, $method_name, $method) = @_;
+
+ push @{ $self->{$modifier}->{$method_name} ||= [] }, $method;
+ return;
+ };
+ my $has_method_modifiers = sub{
+ my($self, $method_name) = @_;
+ my $m = $self->{$modifier}->{$method_name};
+ return $m && @{$m} != 0;
+ };
+ my $get_method_modifiers = sub {
+ my ($self, $method_name) = @_;
+ return @{ $self->{$modifier}->{$method_name} ||= [] }
+ };
+
+ no strict 'refs';
+ *{ 'add_' . $modifier_type . '_method_modifier' } = $add_method_modifier;
+ *{ 'has_' . $modifier_type . '_method_modifiers' } = $has_method_modifiers;
+ *{ 'get_' . $modifier_type . '_method_modifiers' } = $get_method_modifiers;
+}
+
+sub add_override_method_modifier{
+ my($self, $method_name, $method) = @_;
+
+ if($self->has_method($method_name)){
+ # This error happens in the override keyword or during role composition,
+ # so I added a message, "A local method of ...", only for compatibility (gfx)
+ $self->throw_error("Cannot add an override of method '$method_name' "
+ . "because there is a local version of '$method_name'"
+ . "(A local method of the same name as been found)");
+ }
+
+ $self->{override_method_modifiers}->{$method_name} = $method;
+}
+
+sub has_override_method_modifier {
+ my ($self, $method_name) = @_;
+ return exists $self->{override_method_modifiers}->{$method_name};
+}
+
+sub get_override_method_modifier {
+ my ($self, $method_name) = @_;
+ return $self->{override_method_modifiers}->{$method_name};
+}
+
+sub get_method_modifier_list {
+ my($self, $modifier_type) = @_;
+
+ return keys %{ $self->{$modifier_type . '_method_modifiers'} };
+}
+
+# This is currently not passing all the Moose tests.
+sub does_role {
+ my ($self, $role_name) = @_;
+
+ (defined $role_name)
+ || $self->throw_error("You must supply a role name to look for");
+
+ # if we are it,.. then return true
+ return 1 if $role_name eq $self->name;
+ # otherwise.. check our children
+ for my $role (@{ $self->get_roles }) {
+ return 1 if $role->does_role($role_name);
+ }
+ return 0;
+}
-sub has_attribute { exists $_[0]->{attributes}->{$_[1]} }
-sub add_attribute { $_[0]->{attributes}->{$_[1]} = $_[2] }
1;
projects / gitmo/Mouse.git / blobdiff