sub add_required_methods {
my($self, @methods) = @_;
- push @{$self->{required_methods}}, @methods;
+ my %required = map{ $_ => 1 } @{$self->{required_methods}};
+ push @{$self->{required_methods}}, grep{ !$required{$_}++ && !$self->has_method($_) } @methods;
+ return;
}
sub requires_method {
$self->{attributes}->{$name} = (@_ == 1) ? $_[0] : { @_ };
}
-sub _canonicalize_apply_args{
- my($self, $applicant, %args) = @_;
-
- if($applicant->isa('Mouse::Meta::Class')){ # Application::ToClass
- $args{_to} = 'class';
- }
- elsif($applicant->isa('Mouse::Meta::Role')){ # Application::ToRole
- $args{_to} = 'role';
- }
- else{ # Appplication::ToInstance
- $args{_to} = 'class';
-
- my $metaclass = $applicant->meta->create_anon_class(
- superclasses => [ref $applicant],
- cache => 1,
- );
- bless $applicant, $metaclass->name; # rebless
-
- $applicant = $metaclass;
- }
-
- if($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( $applicant, \%args );
-}
-
sub _check_required_methods{
- my($role, $class, $args, @other_roles) = @_;
+ my($role, $applicant, $args) = @_;
- if($args->{_to} eq 'class'){
- my $class_name = $class->name;
+ if($args->{_to} eq 'role'){
+ $applicant->add_required_methods($role->get_required_method_list);
+ }
+ else{ # to class or instance
+ my $class_name = $applicant->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(!($class_name->can($method_name) || exists $args->{to_be_provided}{$method_name})){
+ push @missing, $method_name;
}
}
if(@missing){
- $class->throw_error("'$role_name' requires the "
+ $role->throw_error("'$role_name' requires the "
. (@missing == 1 ? 'method' : 'methods')
. " "
. english_list(map{ sprintf q{'%s'}, $_ } @missing)
. " to be implemented by '$class_name'");
}
}
- else {
- # 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, $applicant, $args) = @_;
my $role_name = $role->name;
- my $class_name = $class->name;
+ my $class_name = $applicant->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);
+ my $code = $role->get_method_body($method_name);
- if(!exists $excludes->{$method_name}){
- if(!$class->has_method($method_name)){
- $class->add_method($method_name => $code);
+ if($excludes && !exists $excludes->{$method_name}){
+ if(!$applicant->has_method($method_name)){
+ # The third argument, $role, is used in Role::Composite
+ $applicant->add_method($method_name => $code, $role);
}
}
if($alias && $alias->{$method_name}){
my $dstname = $alias->{$method_name};
- my $dstcode = do{ no strict 'refs'; *{$class_name . '::' . $dstname}{CODE} };
+ my $dstcode = $applicant->get_method_body($dstname);
if(defined($dstcode) && $dstcode != $code){
- $class->throw_error("Cannot create a method alias if a local method of the same name exists");
+ $role->throw_error("Cannot create a method alias if a local method of the same name exists");
}
else{
- $class->add_method($dstname => $code);
+ $applicant->add_method($dstname => $code, $role);
}
}
}
}
sub _apply_attributes{
- my($role, $class, $args) = @_;
+ my($role, $applicant, $args) = @_;
- if ($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});
- }
- }
- else {
- # apply role to role
- for my $attr_name ($role->get_attribute_list) {
- next if $class->has_attribute($attr_name);
+ for my $attr_name ($role->get_attribute_list) {
+ next if $applicant->has_attribute($attr_name);
- my $spec = $role->get_attribute($attr_name);
- $class->add_attribute($attr_name => $spec);
- }
+ $applicant->add_attribute($attr_name => $role->get_attribute($attr_name));
}
-
return;
}
sub _apply_modifiers{
- my($role, $class, $args) = @_;
+ my($role, $applicant, $args) = @_;
for my $modifier_type (qw/override before around after/) {
+ my $modifiers = $role->{"${modifier_type}_method_modifiers"}
+ or next;
+
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 $method_name (keys %{$modifiers}){
+ my $modifier_codes = $modifiers->{$method_name};
foreach my $code(ref($modifier_codes) eq 'ARRAY' ? @{$modifier_codes} : $modifier_codes){
- $class->$add_modifier($method_name => $code);
+ next if $applicant->{"_$modifier_type"}{$code}++; # skip applied modifiers
+ $applicant->$add_modifier($method_name => $code);
}
}
}
}
sub _append_roles{
- my($role, $class, $args) = @_;
+ my($role, $applicant, $args) = @_;
- my $roles = ($args->{_to} eq 'class') ? $class->roles : $class->get_roles;
+ my $roles = ($args->{_to} eq 'role') ? $applicant->get_roles : $applicant->roles;
foreach my $r($role, @{$role->get_roles}){
- if(!$class->does_role($r->name)){
+ if(!$applicant->does_role($r->name)){
push @{$roles}, $r;
}
}
sub apply {
my $self = shift;
my $applicant = shift;
- my $args;
-
- ($applicant, $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, $args);
- return;
-}
-
-sub combine_apply {
- my($role_class, $applicant, @roles) = @_;
-
- ($applicant) = $role_class->_canonicalize_apply_args($applicant);
- # check conflicting
- my %method_provided;
- my @method_conflicts;
- my %attr_provided;
- my %override_provided;
+ my %args = (@_ == 1) ? %{ $_[0] } : @_;
- 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 $applicant->has_method($method_name); # manually resolved
-
- my $code = do{ no strict 'refs'; \&{ $role_name . '::' . $method_name } };
+ if($applicant->isa('Mouse::Meta::Class')){ # Application::ToClass
+ $args{_to} = 'class';
+ }
+ elsif($applicant->isa('Mouse::Meta::Role')){ # Application::ToRole
+ $args{_to} = 'role';
+ }
+ else{ # Appplication::ToInstance
+ $args{_to} = 'instance';
- my $c = $method_provided{$method_name};
+ my $metaclass = $applicant->meta->create_anon_class(
+ superclasses => [ref $applicant],
+ cache => 1,
+ );
+ bless $applicant, $metaclass->name; # rebless
- if($c && $c->[0] != $code){
- push @{$c}, $role;
- push @method_conflicts, $c;
- }
- else{
- $method_provided{$method_name} = [$code, $method_name, $role];
- }
- }
+ $applicant = $metaclass;
+ }
- # 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){
- $role_class->throw_error("We have encountered an attribute conflict with '$attr_name' "
- . "during composition. This is fatal error and cannot be disambiguated.")
- }
- else{
- $attr_provided{$attr_name} = $attr;
- }
- }
+ if($args{alias} && !exists $args{-alias}){
+ $args{-alias} = $args{alias};
+ }
+ if($args{excludes} && !exists $args{-excludes}){
+ $args{-excludes} = $args{excludes};
+ }
- # 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){
- $role_class->throw_error( "We have encountered an 'override' method conflict with '$method_name' during "
- . "composition (Two 'override' methods of the same name encountered). "
- . "This is fatal error.")
- }
- else{
- $override_provided{$method_name} = $override;
- }
- }
+ # In Moose it is called 'aliased methods'
+ $args{to_be_provided} = {};
+ if(my $alias = $args{-alias}){
+ @{$args{to_be_provided}}{ values %{$alias} } = ();
}
- if(@method_conflicts){
- my $error;
-
- if(@method_conflicts == 1){
- my($code, $method_name, @roles) = @{$method_conflicts[0]};
- $role_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, $applicant->name
- );
+ @{ $args{to_be_provided} }{ $self->get_method_list } = ();
+
+ if(my $excludes = $args{-excludes}){
+ $args{-excludes} = {}; # replace with a hash ref
+ if(ref $excludes){
+ %{$args{-excludes}} = (map{ $_ => undef } @{$excludes});
}
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
- );
-
- $role_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, $applicant->name
- );
+ $args{-excludes}{$excludes} = undef;
}
}
- foreach my $role_spec (@roles) {
- my($role_name, $args) = @{$role_spec};
+ $self->_check_required_methods($applicant, \%args);
+ $self->_apply_attributes($applicant, \%args);
+ $self->_apply_methods($applicant, \%args);
+ $self->_apply_modifiers($applicant, \%args);
+ $self->_append_roles($applicant, \%args);
+ return;
+}
+
- my $role = $role_name->meta;
+sub combine {
+ my($role_class, @role_specs) = @_;
- ($applicant, $args) = $role->_canonicalize_apply_args($applicant, %{$args});
+ require 'Mouse/Meta/Role/Composite.pm'; # we don't want to create its namespace
- $role->_check_required_methods($applicant, $args, @roles);
- $role->_apply_methods($applicant, $args);
- $role->_apply_attributes($applicant, $args);
- $role->_apply_modifiers($applicant, $args);
- $role->_append_roles($applicant, $args);
+ my $composite = Mouse::Meta::Role::Composite->create_anon_role();
+
+ foreach my $role_spec (@role_specs) {
+ my($role_name, $args) = @{$role_spec};
+ $role_name->meta->apply($composite, %{$args});
}
- return;
+ return $composite;
}
for my $modifier_type (qw/before after around/) {
--- /dev/null
+package Mouse::Meta::Role::Composite;
+use Mouse::Util qw(english_list); # enables strict and warnings
+use Mouse::Meta::Role;
+our @ISA = qw(Mouse::Meta::Role);
+
+sub get_method_list{
+ my($self) = @_;
+ return keys %{ $self->{methods} };
+}
+
+sub add_method {
+ my($self, $method_name, $code, $role) = @_;
+
+ if( ($self->{methods}{$method_name} || 0) == $code){
+ # This role already has the same method.
+ return;
+ }
+
+ if($method_name ne 'meta'){
+ my $roles = $self->{composed_roles_by_method}{$method_name} ||= [];
+ push @{$roles}, $role;
+ if(@{$roles} > 1){
+ $self->{conflicting_methods}{$method_name}++;
+ }
+ }
+
+ $self->{methods}{$method_name} = $code;
+ # no need to add a subroutine to the stash
+ return;
+}
+
+sub get_method_body {
+ my($self, $method_name) = @_;
+ return $self->{methods}{$method_name};
+}
+
+sub has_method {
+ # my($self, $method_name) = @_;
+ return 0; # to fool _apply_methods() in combine()
+}
+
+sub has_attribute{
+ # my($self, $method_name) = @_;
+ return 0; # to fool _appply_attributes() in combine()
+}
+
+sub has_override_method_modifier{
+ # my($self, $method_name) = @_;
+ return 0; # to fool _apply_modifiers() in combine()
+}
+
+sub add_attribute{
+ my($self, $attr_name, $spec) = @_;
+
+ my $existing = $self->{attributes}{$attr_name};
+ if($existing && $existing != $spec){
+ $self->throw_error("We have encountered an attribute conflict with '$attr_name' "
+ . "during composition. This is fatal error and cannot be disambiguated.");
+ }
+ $self->SUPER::add_attribute($attr_name, $spec);
+ return;
+}
+
+sub add_override_method_modifier{
+ my($self, $method_name, $code) = @_;
+
+ my $existing = $self->{override_method_modifiers}{$method_name};
+ if($existing && $existing != $code){
+ $self->throw_error( "We have encountered an 'override' method conflict with '$method_name' during "
+ . "composition (Two 'override' methods of the same name encountered). "
+ . "This is fatal error.")
+ }
+ $self->SUPER::add_override_method_modifier($method_name, $code);
+ return;
+}
+
+# components of apply()
+
+sub _apply_methods{
+ my($self, $applicant, $args) = @_;
+
+ if(exists $self->{conflicting_methods}){
+ my $applicant_class_name = $applicant->name;
+
+ my @conflicting = sort grep{ !$applicant_class_name->can($_) } keys %{ $self->{conflicting_methods} };
+
+ if(@conflicting == 1){
+ my $method_name = $conflicting[0];
+ my @roles = sort @{ $self->{composed_roles_by_method}{$method_name} };
+ $self->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, $applicant->name
+ );
+ }
+ elsif(@conflicting > 1){
+ my $methods = english_list(map{ sprintf q{'%s'}, $_ } @conflicting);
+
+ my %seen;
+ my $roles = english_list(
+ sort map{ my $name = $_->name; $seen{$name}++ ? () : sprintf q{'%s'}, $name }
+ map{ @{$_} } @{ $self->{composed_roles_by_method} }{@conflicting}
+ );
+
+ $self->throw_error(
+ sprintf q{Due to method name conflicts in roles %s, the methods %s must be implemented or excluded by '%s'},
+ $roles, $methods, $applicant->name
+ );
+ }
+ }
+
+ $self->SUPER::_apply_methods($applicant, $args);
+ return;
+}
+1;
+__END__
+