X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?p=gitmo%2FMouse.git;a=blobdiff_plain;f=lib%2FMouse%2FMeta%2FAttribute.pm;h=dec1a54e89b8d426a5f69000316ea480762d4f66;hp=22b87cb021deb2dd88dbb5b9174fa0bd21f2019c;hb=2efc0af104c1926c066f50e1785236254bda12a2;hpb=028b550b1a533daca23d2ea942a60d90a1380e1f

diff --git a/lib/Mouse/Meta/Attribute.pm b/lib/Mouse/Meta/Attribute.pm
index 22b87cb..dec1a54 100644
--- a/lib/Mouse/Meta/Attribute.pm
+++ b/lib/Mouse/Meta/Attribute.pm
@@ -1,277 +1,278 @@
-#!/usr/bin/env perl
 package Mouse::Meta::Attribute;
 use strict;
 use warnings;
 
-use Carp 'confess';
-use Scalar::Util 'blessed';
+use Carp ();
+use Scalar::Util qw(weaken);
+
+use Mouse::Util;
+
+use Mouse::Meta::TypeConstraint;
+use Mouse::Meta::Method::Accessor;
+
+#my %valid_attrs = map{ $_ => undef } qw(
+#    name
+#    reader writer accessor clearer predicate
+#    builder init_arg default initializer definition_context
+#
+#    is
+#    isa does
+#    required
+#    lazy
+#    lazy_build
+#    coerce
+#    weak_ref
+#    auto_deref
+#    type_constraint
+#    trigger
+#    handles
+#    documentation
+#    traits
+#);
 
 sub new {
-    my $class = shift;
-    my %args  = @_;
+    my ($class, $name, %options) = @_;
 
-    my $name = $args{name};
+    # taken from Class::MOP::Attribute::new
 
-    $args{init_arg} = $name
-        unless exists $args{init_arg};
+    defined($name)
+        or $class->throw_error('You must provide a name for the attribute');
+    $options{name} = $name;
 
-    $args{is} ||= '';
+    if(!exists $options{init_arg}){
+        $options{init_arg} = $name;
+    }
 
-    if ($args{lazy_build}) {
-        confess("You can not use lazy_build and default for the same attribute $name")
-            if exists $args{default};
-        $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});
+    # 'required' requires eigher 'init_arg', 'builder', or 'default'
+    my $can_be_required = defined( $options{init_arg} );
+
+    if(exists $options{builder}){
+        $class->throw_error('builder must be a defined scalar value which is a method name')
+            if ref $options{builder} || !(defined $options{builder});
+
+        $can_be_required++;
+    }
+    elsif(exists $options{default}){
+        if(ref $options{default} && ref($options{default}) ne 'CODE'){
+            $class->throw_error("References are not allowed as default values, you must "
+                              . "wrap the default of '$name' in a CODE reference (ex: sub { [] } and not [])");
         }
+        $can_be_required++;
     }
 
-    bless \%args, $class;
-}
+    if( $options{required} && !$can_be_required ) {
+        $class->throw_error("You cannot have a required attribute ($name) without a default, builder, or an init_arg");
+    }
 
-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 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 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}         }
+    # taken from Mouse::Meta::Attribute->new and _process_options
 
-sub _create_args {
-    $_[0]->{_create_args} = $_[1] if @_ > 1;
-    $_[0]->{_create_args}
-}
+    if(exists $options{is}){
+        my $is = $options{is};
 
-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 $accessor = 'sub {
-        my $self = shift;';
-
-    if ($attribute->_is_metadata eq 'rw') {
-        $accessor .= 'if (@_) {
-            local $_ = $_[0];';
-
-        if ($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 $constraint->();
-            };'
+        if($is eq 'ro'){
+            $options{reader} ||= $name;
         }
-
-        $accessor .= '$self->{$key} = $_;';
-
-        if ($attribute->is_weak_ref) {
-            $accessor .= 'Scalar::Util::weaken($self->{$key}) if ref($self->{$key});';
+        elsif($is eq 'rw'){
+            if(exists $options{writer}){
+                $options{reader} ||= $name;
+             }
+             else{
+                $options{accessor} ||= $name;
+             }
         }
-
-        if ($trigger) {
-            $accessor .= '$trigger->($self, $_, $attribute);';
+        elsif($is eq 'bare'){
+            # do nothing, but don't complain (later) about missing methods
         }
+        else{
+            $is = 'undef' if !defined $is;
+            $class->throw_error("I do not understand this option (is => $is) on attribute ($name)");
+        }
+    }
 
-        $accessor .= '}';
+    my $tc;
+    if(exists $options{isa}){
+        $options{type_constraint} = Mouse::Util::TypeConstraints::find_or_create_isa_type_constraint($options{isa});
     }
-    else {
-        $accessor .= 'confess "Cannot assign a value to a read-only accessor" if @_;';
+    elsif(exists $options{does}){
+        $options{type_constraint} = Mouse::Util::TypeConstraints::find_or_create_does_type_constraint($options{does});
     }
+    $tc = $options{type_constraint};
 
-    if ($attribute->is_lazy) {
-        $accessor .= '$self->{$key} = ';
-
-        $accessor .= $attribute->has_builder
-                   ? '$self->$builder'
-                     : ref($default) eq 'CODE'
-                     ? '$default->($self)'
-                     : '$default';
+    if($options{coerce}){
+        defined($tc)
+            || $class->throw_error("You cannot have coercion without specifying a type constraint on attribute ($name)");
 
-        $accessor .= ' if !exists($self->{$key});';
+        $options{weak_ref}
+            && $class->throw_error("You cannot have a weak reference to a coerced value on attribute ($name)");
     }
 
-    if ($attribute->should_auto_deref) {
-        if ($attribute->type_constraint eq 'ArrayRef') {
-            $accessor .= 'if (wantarray) {
-                return @{ $self->{$key} || [] };
-            }';
-        }
-        else {
-            $accessor .= 'if (wantarray) {
-                return %{ $self->{$key} || {} };
-            }';
-        }
+    if ($options{lazy_build}) {
+        exists($options{default})
+            && $class->throw_error("You can not use lazy_build and default for the same attribute ($name)");
+
+        $options{lazy}      = 1;
+        $options{builder} ||= "_build_${name}";
+        if ($name =~ /^_/) {
+            $options{clearer}   ||= "_clear${name}";
+            $options{predicate} ||= "_has${name}";
+        }
+        else {
+            $options{clearer}   ||= "clear_${name}";
+            $options{predicate} ||= "has_${name}";
+        }
     }
 
-    $accessor .= 'return $self->{$key};
-    }';
+    if ($options{auto_deref}) {
+        defined($tc)
+            || $class->throw_error("You cannot auto-dereference without specifying a type constraint on attribute ($name)");
 
-    return eval $accessor;
-}
-
-sub generate_predicate {
-    my $attribute = shift;
-    my $key = $attribute->name;
-
-    my $predicate = 'sub { exists($_[0]->{$key}) }';
-
-    return eval $predicate;
-}
+        ( $tc->is_a_type_of('ArrayRef') || $tc->is_a_type_of('HashRef') )
+            || $class->throw_error("You cannot auto-dereference anything other than a ArrayRef or HashRef on attribute ($name)");
+    }
 
-sub generate_clearer {
-    my $attribute = shift;
-    my $key = $attribute->name;
+    if (exists $options{trigger}) {
+        ('CODE' eq ref $options{trigger})
+            || $class->throw_error("Trigger must be a CODE ref on attribute ($name)");
+    }
 
-    my $predicate = 'sub { delete($_[0]->{$key}) }';
+    if ($options{lazy}) {
+        (exists $options{default} || defined $options{builder})
+            || $class->throw_error("You cannot have lazy attribute ($name) without specifying a default value for it");
+    }
 
-    return eval $predicate;
-}
+    if(my $metaclass = delete $options{metaclass}){
+        $class = Mouse::Util::resolve_metaclass_alias( Attribute => $metaclass );
+    }
 
-sub generate_handles {
-    my $attribute = shift;
-    my $reader = $attribute->name;
-    my %handles = $attribute->_canonicalize_handles($attribute->handles);
+    if(my $traits_ref = delete $options{traits}){
+        my @traits;
+        for (my $i = 9; $i < @{$traits_ref}; $i++) {
+            my $trait = Mouse::Util::resolve_metaclass_alias(Attribute => $traits_ref->[$i], trait => 1);
+
+            next if $class->does($trait);
+
+            push @traits, $trait;
+
+            # are there options?
+            push @traits, $traits_ref->[++$i]
+                if ref($traits_ref->[$i+1]);
+        }
 
-    my %method_map;
+        if (@traits) {
+            $class = Mouse::Meta::Class->create_anon_class(
+                superclasses => [ $class ],
+                roles        => [ @traits ],
+                cache        => 1,
+            )->name;
+        }
+    }
 
-    for my $local_method (keys %handles) {
-        my $remote_method = $handles{$local_method};
+# XXX: there is no fast way to check attribute validity
+#    my @bad = grep{ !exists $valid_attrs{$_} } keys %options;
+#    if(@bad){
+#        @bad = sort @bad;
+#        Carp::cluck("Found unknown argument(s) passed to '$name' attribute constructor in '$class': @bad");
+#    }
 
-        my $method = 'sub {
-            my $self = shift;
-            $self->$reader->$remote_method(@_)
-        }';
+    return bless \%options, $class;
+}
 
-        $method_map{$local_method} = eval $method;
-    }
+# readers
+
+sub name                 { $_[0]->{name}                   }
+sub associated_class     { $_[0]->{associated_class}       }
+
+sub accessor             { $_[0]->{accessor}               }
+sub reader               { $_[0]->{reader}                 }
+sub writer               { $_[0]->{writer}                 }
+sub predicate            { $_[0]->{predicate}              }
+sub clearer              { $_[0]->{clearer}                }
+sub handles              { $_[0]->{handles}                }
+
+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 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]->{coerce}                 }
+
+# predicates
+
+sub has_accessor         { exists $_[0]->{accessor}        }
+sub has_reader           { exists $_[0]->{reader}          }
+sub has_writer           { exists $_[0]->{writer}          }
+sub has_predicate        { exists $_[0]->{predicate}       }
+sub has_clearer          { exists $_[0]->{clearer}         }
+sub has_handles          { exists $_[0]->{handles}         }
+
+sub has_default          { exists $_[0]->{default}         }
+sub has_type_constraint  { exists $_[0]->{type_constraint} }
+sub has_trigger          { exists $_[0]->{trigger}         }
+sub has_builder          { exists $_[0]->{builder}         }
 
-    return \%method_map;
+sub _create_args {
+    $_[0]->{_create_args} = $_[1] if @_ > 1;
+    $_[0]->{_create_args}
 }
 
+sub accessor_metaclass { 'Mouse::Meta::Method::Accessor' }
+
 sub create {
     my ($self, $class, $name, %args) = @_;
 
-    $args{name} = $name;
-    $args{class} = $class;
-
-    $self->validate_args($name, %args);
+    my $attribute = $self->new($name, %args);
 
-    $args{type_constraint} = delete $args{isa}
-        if exists $args{isa};
-
-    my $attribute = $self->new(%args);
     $attribute->_create_args(\%args);
 
-    my $meta = $class->meta;
+    $class->add_attribute($attribute);
+    weaken($attribute->{associated_class} = $class);
 
-    $meta->add_attribute($attribute);
+    my $associated_methods = 0;
 
-    # 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;
-    }
-
-    for my $method (qw/predicate clearer/) {
-        my $predicate = "has_$method";
-        if ($attribute->$predicate) {
-            my $generator = "generate_$method";
-            my $coderef = $attribute->$generator;
-            no strict 'refs';
-            *{ $class . '::' . $attribute->$method } = $coderef;
+    my $generator_class = $self->accessor_metaclass;
+    foreach my $type(qw(accessor reader writer predicate clearer handles)){
+        if(exists $attribute->{$type}){
+            my $installer    = '_install_' . $type;
+            $generator_class->$installer($attribute, $attribute->{$type}, $class);
+            $associated_methods++;
         }
     }
 
-    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};
-        }
+    if($associated_methods == 0 && ($attribute->_is_metadata || '') ne 'bare'){
+        Carp::cluck(qq{Attribute ($name) of class }.$class->name.qq{ has no associated methods (did you mean to provide an "is" argument?)});
+
     }
 
     return $attribute;
 }
 
-sub validate_args {
-    my $self = shift;
-    my $name = shift;
-    my %args = @_;
-
-    confess "You cannot have lazy attribute ($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';
+sub verify_against_type_constraint {
+    my ($self, $value) = @_;
+    my $tc = $self->type_constraint;
+    return 1 unless $tc;
 
-    confess "You cannot auto-dereference without specifying a type constraint on attribute $name"
-        if $args{auto_deref} && !exists($args{isa});
+    local $_ = $value;
+    return 1 if $tc->check($value);
 
-    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';
-
-    return 1;
+    $self->verify_type_constraint_error($self->name, $value, $tc);
 }
 
-sub find_type_constraint {
-    my $self = shift;
-    my $type = $self->type_constraint;
-
-    return unless $type;
-
-    my $checker = Mouse::TypeRegistry->optimized_constraints->{$type};
-    return $checker if $checker;
-
-    return sub { blessed($_) && blessed($_) eq $type };
+sub verify_type_constraint_error {
+    my($self, $name, $value, $type) = @_;
+    $self->throw_error("Attribute ($name) does not pass the type constraint because: " . $type->get_message($value));
 }
 
-sub verify_type_constraint {
-    my $self = shift;
-    local $_ = shift;
-
-    my $type = $self->type_constraint
-        or return 1;
-    my $constraint = $self->find_type_constraint;
-
-    return 1 if $constraint->($_);
-
-    my $name = $self->name;
-    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 $_[1];
+    return Mouse::Util::TypeConstraints->typecast_constraints($_[0]->associated_class->name, $_[0]->type_constraint, $_[1]);
 }
 
 sub _canonicalize_handles {
@@ -285,7 +286,7 @@ sub _canonicalize_handles {
         return map { $_ => $_ } @$handles;
     }
     else {
-        confess "Unable to canonicalize the 'handles' option with $handles";
+        $self->throw_error("Unable to canonicalize the 'handles' option with $handles");
     }
 }
 
@@ -303,13 +304,20 @@ sub get_parent_args {
     my $class = shift;
     my $name  = shift;
 
-    for my $super ($class->meta->linearized_isa) {
+    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";
+    $self->throw_error("Could not find an attribute by the name of '$name' to inherit from");
+}
+
+sub throw_error{
+    my $self = shift;
+
+    my $metaclass = (ref $self && $self->associated_class) || 'Mouse::Meta::Class';
+    $metaclass->throw_error(@_, depth => 1);
 }
 
 1;
@@ -333,7 +341,7 @@ installed. Some error checking is done.
 
 =head2 name -> AttributeName
 
-=head2 class -> OwnerClass
+=head2 associated_class -> OwnerClass
 
 =head2 is_required -> Bool
 
@@ -377,31 +385,31 @@ installed. Some error checking is done.
 
 Informational methods.
 
-=head2 generate_accessor -> CODE
-
-Creates a new code reference for the attribute's accessor.
-
-=head2 generate_predicate -> CODE
+=head2 verify_against_type_constraint Item -> 1 | ERROR
 
-Creates a new code reference for the attribute's predicate.
+Checks that the given value passes this attribute's type constraint. Returns 1
+on success, otherwise C<confess>es.
 
-=head2 generate_clearer -> CODE
+=head2 canonicalize_args Name, %args -> %args
 
-Creates a new code reference for the attribute's clearer.
+Canonicalizes some arguments to create. In particular, C<lazy_build> is
+canonicalized into C<lazy>, C<builder>, etc.
 
-=head2 generate_handles -> { MethodName => CODE }
+=head2 validate_args Name, \%args -> 1 | ERROR
 
-Creates a new code reference for each of the attribute's handles methods.
+Checks that the arguments to create the attribute (ie those specified by
+C<has>) are valid.
 
-=head2 find_type_constraint -> CODE
+=head2 clone_parent OwnerClass, AttributeName, %args -> Mouse::Meta::Attribute
 
-Returns a code reference which can be used to check that a given value passes
-this attribute's type constraint;
+Creates a new attribute in OwnerClass, inheriting options from parent classes.
+Accessors and helper methods are installed. Some error checking is done.
 
-=head2 verify_type_constraint Item -> 1 | ERROR
+=head2 get_parent_args OwnerClass, AttributeName -> Hash
 
-Checks that the given value passes this attribute's type constraint. Returns 1
-on success, otherwise C<confess>es.
+Returns the options that the parent class of C<OwnerClass> used for attribute
+C<AttributeName>.
 
 =cut
 
+
\ No newline at end of file