X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FMouse%2FMeta%2FAttribute.pm;h=0f0475931b708d15186228af3c487655b30642cd;hb=3b8fe109e938b2c1cbd70d8072210dd22cd57f35;hp=6a8c88800169c127fef73039f5f222292e75dc95;hpb=58af95b87869e95b132806405054324491903fa1;p=gitmo%2FMouse.git

diff --git a/lib/Mouse/Meta/Attribute.pm b/lib/Mouse/Meta/Attribute.pm
index 6a8c888..0f04759 100644
--- a/lib/Mouse/Meta/Attribute.pm
+++ b/lib/Mouse/Meta/Attribute.pm
@@ -1,36 +1,43 @@
 #!/usr/bin/env perl
-package Mouse::Attribute;
+package Mouse::Meta::Attribute;
 use strict;
 use warnings;
+require overload;
 
 use Carp 'confess';
-use Scalar::Util 'blessed';
+use Mouse::Util qw/blessed weaken/;
 
 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 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 has_default         { exists $_[0]->{default}         }
 sub has_predicate       { exists $_[0]->{predicate}       }
@@ -40,81 +47,124 @@ 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 $type          = $attribute->type_constraint;
+    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 $constraint->();
-            };'
+            if ($should_coerce) {
+                $accessor .= $value.' = $attribute->coerce_constraint('.$value.');';
+            }
+            $accessor .= 'local $_ = '.$value.';';
+            $accessor .= '
+                unless ($constraint->()) {
+                    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");
+            }' . "\n"
         }
 
-        $accessor .= '$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;
+
+        $accessor .= $self.'->{'.$key.'} = '.$value.';' . "\n";
 
-        if ($attribute->is_weak_ref) {
-            $accessor .= 'Scalar::Util::weaken($self->{$key}) if ref($self->{$key});';
+        if ($is_weak) {
+            $accessor .= 'weaken('.$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) {
+        if ($attribute->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 {
@@ -133,6 +183,7 @@ sub generate_handles {
         }';
 
         $method_map{$local_method} = eval $method;
+        confess $@ if $@;
     }
 
     return \%method_map;
@@ -141,26 +192,28 @@ sub generate_handles {
 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});
+    $args{name} = $name;
+    $args{associated_class} = $class;
 
-    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 = $self->canonicalize_args($name, %args);
+    $self->validate_args($name, \%args);
+
+    $args{should_coerce} = delete $args{coerce}
+        if exists $args{coerce};
 
     $args{type_constraint} = delete $args{isa}
         if exists $args{isa};
 
-    my $attribute = $self->new(%args, name => $name, class => $class);
-    my $meta = $class->meta;
+    my $attribute = $self->new(%args);
 
-    $meta->add_attribute($attribute);
+    $attribute->_create_args(\%args);
+
+    $class->add_attribute($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 $method (qw/predicate clearer/) {
@@ -168,29 +221,87 @@ sub create {
         if ($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 canonicalize_args {
+    my $self = shift;
+    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;
+}
+
+sub validate_args {
+    my $self = shift;
+    my $name = shift;
+    my $args = shift;
+
+    confess "You can not use lazy_build and default for the same attribute ($name)"
+        if $args->{lazy_build} && exists $args->{default};
+
+    confess "You cannot have lazy attribute ($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 find_type_constraint {
     my $self = shift;
     my $type = $self->type_constraint;
 
     return unless $type;
 
-    my $checker = Mouse::TypeRegistry->optimized_constraints->{$type};
+    my $checker = Mouse::TypeRegistry->optimized_constraints($self->associated_class->name)->{$type};
     return $checker if $checker;
 
     return sub { blessed($_) && blessed($_) eq $type };
@@ -211,6 +322,13 @@ sub verify_type_constraint {
     Carp::confess("Attribute ($name) does not pass the type constraint because: Validation failed for \'$type\' failed with value $display");
 }
 
+sub coerce_constraint {
+    my($self, $value) = @_;
+    my $type = $self->type_constraint
+        or return $value;
+    return Mouse::TypeRegistry->typecast_constraints($self->associated_class->name, $type, $value);
+}
+
 sub _canonicalize_handles {
     my $self    = shift;
     my $handles = shift;
@@ -226,28 +344,51 @@ sub _canonicalize_handles {
     }
 }
 
+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__
 
 =head1 NAME
 
-Mouse::Attribute - attribute metaclass
+Mouse::Meta::Attribute - attribute metaclass
 
 =head1 METHODS
 
-=head2 new %args -> Mouse::Attribute
+=head2 new %args -> Mouse::Meta::Attribute
 
-Instantiates a new Mouse::Attribute. Does nothing else.
+Instantiates a new Mouse::Meta::Attribute. Does nothing else.
 
-=head2 create OwnerClass, AttributeName, %args -> Mouse::Attribute
+=head2 create OwnerClass, AttributeName, %args -> Mouse::Meta::Attribute
 
 Creates a new attribute in OwnerClass. Accessors and helper methods are
 installed. Some error checking is done.
 
 =head2 name -> AttributeName
 
-=head2 class -> OwnerClass
+=head2 associated_class -> OwnerClass
 
 =head2 is_required -> Bool
 
@@ -285,6 +426,10 @@ installed. Some error checking is done.
 
 =head2 has_builder -> Bool
 
+=head2 is_lazy_build => Bool
+
+=head2 should_auto_deref -> Bool
+
 Informational methods.
 
 =head2 generate_accessor -> CODE
@@ -313,5 +458,25 @@ this attribute's type constraint;
 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