X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FMouse%2FMeta%2FRole.pm;h=33b84262c3ea64daa7f6afabb1e6fe345352aa08;hb=60b5c3be4d0b3bb705df1e8d977f2ce90db6668d;hp=ff0c439d7c8e5ed2a9096b32880e97e74e843d27;hpb=3a63a2e7ef8fbac5f61eab04baecbf5d19374b83;p=gitmo%2FMouse.git

diff --git a/lib/Mouse/Meta/Role.pm b/lib/Mouse/Meta/Role.pm
index ff0c439..33b8426 100644
--- a/lib/Mouse/Meta/Role.pm
+++ b/lib/Mouse/Meta/Role.pm
@@ -1,31 +1,11 @@
 package Mouse::Meta::Role;
 use strict;
 use warnings;
-use Carp 'confess';
 
+use Mouse::Util qw(not_supported english_list);
 use base qw(Mouse::Meta::Module);
 
-do {
-    my %METACLASS_CACHE;
-
-    # 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};
-    }
-
-    sub initialize {
-        my($class, $package_name, @args) = @_;
-
-        ($package_name && !ref($package_name))
-            || confess("You must pass a package name and it cannot be blessed");
-
-        return $METACLASS_CACHE{$package_name}
-            ||= $class->_new(package => $package_name, @args);
-    }
-};
+sub method_metaclass(){ 'Mouse::Meta::Role::Method' } # required for get_method()
 
 sub _new {
     my $class = shift;
@@ -39,22 +19,29 @@ sub _new {
     bless \%args, $class;
 }
 
+sub get_roles { $_[0]->{roles} }
+
+sub get_required_method_list{
+    return @{ $_[0]->{required_methods} };
+}
+
 sub add_required_methods {
     my $self = shift;
     my @methods = @_;
     push @{$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;
-    my $spec = shift;
-    $self->{attributes}->{$name} = $spec;
-}
 
-sub has_attribute { exists $_[0]->{attributes}->{$_[1]}  }
-sub get_attribute_list { keys %{ $_[0]->{attributes} } }
-sub get_attribute { $_[0]->{attributes}->{$_[1]} }
+    $self->{attributes}->{$name} = (@_ == 1) ? $_[0] : { @_ };
+}
 
 sub _check_required_methods{
     my($role, $class, $args, @other_roles) = @_;
@@ -74,7 +61,7 @@ sub _check_required_methods{
                     }
                 }
                 
-                confess "'$role_name' requires the method '$method_name' to be implemented by '$class_name'"
+                $role->throw_error("'$role_name' requires the method '$method_name' to be implemented by '$class_name'")
                     unless $has_method;
             }
         }
@@ -88,23 +75,38 @@ sub _apply_methods{
 
     my $role_name  = $role->name;
     my $class_name = $class->name;
-    my $alias      = $args->{alias};
+
+    my $alias    = (exists $args->{alias}    && !exists $args->{-alias})    ? $args->{alias}    : $args->{-alias};
+    my $excludes = (exists $args->{excludes} && !exists $args->{-excludes}) ? $args->{excludes} : $args->{-excludes};
+
+    my %exclude_map;
+
+    if(defined $excludes){
+        if(ref $excludes){
+            %exclude_map = map{ $_ => undef } @{$excludes};
+        }
+        else{
+            $exclude_map{$excludes} = undef;
+        }
+    }
 
     foreach my $method_name($role->get_method_list){
         next if $method_name eq 'meta';
 
         my $code = $role_name->can($method_name);
-        if(do{ no strict 'refs'; defined &{$class_name . '::' . $method_name} }){
-            # XXX what's Moose's behavior?
-        }
-        else{
-            $class->add_method($method_name => $code);
+
+        if(!exists $exclude_map{$method_name}){
+            if(!$class->has_method($method_name)){
+                $class->add_method($method_name => $code);
+            }
         }
 
         if($alias && $alias->{$method_name}){
             my $dstname = $alias->{$method_name};
-            if(do{ no strict 'refs'; defined &{$class_name . '::' . $dstname} }){
-                # XXX wat's Moose's behavior?
+
+            my $slot = do{ no strict 'refs'; \*{$class_name . '::' . $dstname} };
+            if(defined(*{$slot}{CODE}) && *{$slot}{CODE} != $code){
+                $class->throw_error("Cannot create a method alias if a local method of the same name exists");
             }
             else{
                 $class->add_method($dstname => $code);
@@ -156,7 +158,7 @@ sub _apply_modifiers{
         my $modifiers    = $role->{"${modifier_type}_method_modifiers"};
 
         while(my($method_name, $modifier_codes) = each %{$modifiers}){
-            foreach my $code(@{$modifier_codes}){
+            foreach my $code(ref($modifier_codes) eq 'ARRAY' ? @{$modifier_codes} : $modifier_codes){
                 $class->$add_modifier($method_name => $code);
             }
         }
@@ -182,7 +184,7 @@ sub apply {
     my($self, $class, %args) = @_;
 
     if ($class->isa('Mouse::Object')) {
-        Carp::croak('Mouse does not support Application::ToInstance yet');
+        not_supported 'Application::ToInstance';
     }
 
     $self->_check_required_methods($class, \%args);
@@ -196,6 +198,85 @@ sub apply {
 sub combine_apply {
     my(undef, $class, @roles) = @_;
 
+    # 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};
 
@@ -210,7 +291,7 @@ sub combine_apply {
     return;
 }
 
-for my $modifier_type (qw/before after around override/) {
+for my $modifier_type (qw/before after around/) {
 
     my $modifier = "${modifier_type}_method_modifiers";
     my $add_method_modifier =  sub {
@@ -219,6 +300,11 @@ for my $modifier_type (qw/before after around override/) {
         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} ||= [] }
@@ -226,17 +312,46 @@ for my $modifier_type (qw/before after around override/) {
 
     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 get_roles { $_[0]->{roles} }
+sub add_override_method_modifier{
+    my($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)
-        || confess "You must supply a role name to look for";
+        || $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;