changes so far

[gitmo/Moose.git] / lib / Moose / Meta / Method / Accessor.pm

package Moose::Meta::Method::Accessor;

use strict;
use warnings;

use Carp 'confess';

our $VERSION   = '0.06';
our $AUTHORITY = 'cpan:STEVAN';

use base 'Moose::Meta::Method',
         'Class::MOP::Method::Accessor';

## Inline method generators

sub generate_accessor_method_inline {
    my $self        = $_[0];
    my $attr        = $self->associated_attribute;
    my $attr_name   = $attr->name;
    my $inv         = '$_[0]';
    my $slot_access = $self->_inline_access($inv, $attr_name);
    my $value_name  = $attr->should_coerce ? '$val' : '$_[1]';

    my $code = 'sub { ' . "\n"
    . $self->_inline_pre_body(@_) . "\n"
    . 'if (scalar(@_) == 2) {' . "\n"
        . $self->_inline_check_required . "\n"
        . $self->_inline_check_coercion . "\n"
        . $self->_inline_check_constraint($value_name) . "\n"
                . $self->_inline_store($inv, $value_name) . "\n"
                . $self->_inline_trigger($inv, $value_name) . "\n"
    . ' }' . "\n"
    . $self->_inline_check_lazy . "\n"
    . $self->_inline_post_body(@_) . "\n"
    . 'return ' . $self->_inline_auto_deref($self->_inline_get($inv)) . "\n"
    . ' }';

    # NOTE:
    # set up the environment
    my $type_constraint = $attr->type_constraint
                                ? $attr->type_constraint->_compiled_type_constraint
                                : undef;

    my $sub = eval $code;
    confess "Could not create accessor for '$attr_name' because $@ \n code: $code" if $@;
    return $sub;
}

sub generate_writer_method_inline {
    my $self        = $_[0];
    my $attr        = $self->associated_attribute;
    my $attr_name   = $attr->name;
    my $inv         = '$_[0]';
    my $slot_access = $self->_inline_get($inv, $attr_name);
    my $value_name  = $attr->should_coerce ? '$val' : '$_[1]';

    my $code = 'sub { '
    . $self->_inline_pre_body(@_)
    . $self->_inline_check_required
    . $self->_inline_check_coercion
        . $self->_inline_check_constraint($value_name)
        . $self->_inline_store($inv, $value_name)
        . $self->_inline_post_body(@_)
        . $self->_inline_trigger($inv, $value_name)
    . ' }';

    # NOTE:
    # set up the environment
    my $type_constraint = $attr->type_constraint
                                ? $attr->type_constraint->_compiled_type_constraint
                                : undef;

    my $sub = eval $code;
    confess "Could not create writer for '$attr_name' because $@ \n code: $code" if $@;
    return $sub;
}

sub generate_reader_method_inline {
    my $self        = $_[0];
    my $attr        = $self->associated_attribute;
    my $attr_name   = $attr->name;
    my $inv         = '$_[0]';
    my $slot_access = $self->_inline_get($inv, $attr_name);

    my $code = 'sub {'
    . $self->_inline_pre_body(@_)
    . 'confess "Cannot assign a value to a read-only accessor" if @_ > 1;'
    . $self->_inline_check_lazy
    . $self->_inline_post_body(@_)
    . 'return ' . $self->_inline_auto_deref( $slot_access ) . ';'
    . '}';

    # NOTE:
    # set up the environment
    my $type_constraint = $attr->type_constraint
                                ? $attr->type_constraint->_compiled_type_constraint
                                : undef;

    my $sub = eval $code;
    confess "Could not create reader for '$attr_name' because $@ \n code: $code" if $@;
    return $sub;
}

sub generate_reader_method { shift->generate_reader_method_inline(@_) }
sub generate_writer_method { shift->generate_writer_method_inline(@_) }
sub generate_accessor_method { shift->generate_accessor_method_inline(@_) }

sub _inline_pre_body  { '' }
sub _inline_post_body { '' }

sub _inline_check_constraint {
        my ($self, $value) = @_;

        my $attr = $self->associated_attribute;

        return '' unless $attr->has_type_constraint;

        # FIXME
        # This sprintf is insanely annoying, we should
        # fix it someday - SL
        return sprintf <<'EOF', $value, $value, $value, $value, $value, $value, $value
defined($type_constraint->(%s))
        || confess "Attribute (" . $attr->name . ") does not pass the type constraint ("
       . $attr->type_constraint->name . ") with "
       . (defined(%s) ? (Scalar::Util::blessed(%s) && overload::Overloaded(%s) ? overload::StrVal(%s) : %s) : "undef")
  if defined(%s);
EOF
}

sub _inline_check_coercion {
        my $attr = (shift)->associated_attribute;

        return '' unless $attr->should_coerce;
    return 'my $val = $attr->type_constraint->coerce($_[1]);'
}

sub _inline_check_required {
        my $attr = (shift)->associated_attribute;

        return '' unless $attr->is_required;
    return 'defined($_[1]) || confess "Attribute ($attr_name) is required, so cannot be set to undef";'
}

sub _inline_check_lazy {
    my $self = $_[0];
    my $attr = $self->associated_attribute;

        return '' unless $attr->is_lazy;

    my $inv         = '$_[0]';
    my $slot_access = $self->_inline_access($inv, $attr->name);
    my $slot_exists = $self->_inline_has($inv, $attr->name);
        if ($attr->has_type_constraint) {
            # NOTE:
            # this could probably be cleaned
            # up and streamlined a little more
            return 'unless (' . $slot_exists . ') {' .
                   '    if ($attr->has_default || $attr->has_builder ) {' .
                   '        my $default; '.
                   '        $default = $attr->default(' . $inv . ')  if $attr->has_default;' .
                   '        if ( $attr->has_builder ) { '.
                   '            my $builder = $self->builder;'.
                   '            if($builder = '.$inv.'->can($builder)){ '.
                   '                $default = '.$inv.'->$builder; '.
                   '            } else { '.
                   '                confess(blessed('.$inv.')." does not support builder method \'$builder\' for attribute \'" . $attr->name . "\'");'.
                   '            }'.
                   '        }'.
                   ($attr->should_coerce
                       ? '$default = $attr->type_constraint->coerce($default);'
                       : '') .
               '        (defined($type_constraint->($default)))' .
               '                || confess "Attribute (" . $attr->name . ") does not pass the type constraint ("' .
               '               . $attr->type_constraint->name . ") with " . (defined($default) ? (Scalar::Util::blessed($default) && overload::Overloaded($default) ? overload::StrVal($default) : $default) : "undef")' .
               '          if defined($default);' .
                   '        ' . $slot_access . ' = $default; ' .
                   '    }' .
                   '    else {' .
               '        ' . $slot_access . ' = undef;' .
                   '    }' .
                   '}';
        }

    return  'unless ( ' . $slot_exists . ') {' .
            '    if ($attr->has_default) { ' . $slot_access . ' = $attr->default(' . $inv . '); }' .
            '    elsif ($attr->has_builder) { '.
            '        my $builder = $attr->builder; ' .
            '        if($builder = '.$inv.'->can($builder)){ '.
            '            ' . $slot_access . ' = ' . $inv . '->$builder; '.
            '        } else { '.
            '            confess(blessed('.$inv.')." does not support builder method \'$builder\' for attribute \'" . $attr->name . "\'");'.
            '        }'.
            '    } else { ' .$slot_access . ' = undef; } '.
            '}';
}


sub _inline_store {
        my ($self, $instance, $value) = @_;
        my $attr = $self->associated_attribute;

        my $mi = $attr->associated_class->get_meta_instance;
        my $slot_name = sprintf "'%s'", $attr->slots;

    my $code = $mi->inline_set_slot_value($instance, $slot_name, $value)    . ";";
        $code   .= $mi->inline_weaken_slot_value($instance, $slot_name, $value) . ";"
            if $attr->is_weak_ref;
    return $code;
}

sub _inline_trigger {
        my ($self, $instance, $value) = @_;
        my $attr = $self->associated_attribute;
        return '' unless $attr->has_trigger;
        return sprintf('$attr->trigger->(%s, %s, $attr);', $instance, $value);
}

sub _inline_get {
        my ($self, $instance) = @_;
        my $attr = $self->associated_attribute;

        my $mi = $attr->associated_class->get_meta_instance;
        my $slot_name = sprintf "'%s'", $attr->slots;

    return $mi->inline_get_slot_value($instance, $slot_name);
}

sub _inline_access {
        my ($self, $instance) = @_;
        my $attr = $self->associated_attribute;

        my $mi = $attr->associated_class->get_meta_instance;
        my $slot_name = sprintf "'%s'", $attr->slots;

    return $mi->inline_slot_access($instance, $slot_name);
}

sub _inline_has {
        my ($self, $instance) = @_;
        my $attr = $self->associated_attribute;

        my $mi = $attr->associated_class->get_meta_instance;
        my $slot_name = sprintf "'%s'", $attr->slots;

    return $mi->inline_is_slot_initialized($instance, $slot_name);
}

sub _inline_auto_deref {
    my ( $self, $ref_value ) = @_;
        my $attr = $self->associated_attribute;

    return $ref_value unless $attr->should_auto_deref;

    my $type_constraint = $attr->type_constraint;

    my $sigil;
    if ($type_constraint->is_a_type_of('ArrayRef')) {
        $sigil = '@';
    }
    elsif ($type_constraint->is_a_type_of('HashRef')) {
        $sigil = '%';
    }
    else {
        confess "Can not auto de-reference the type constraint '" . $type_constraint->name . "'";
    }

    "(wantarray() ? $sigil\{ ( $ref_value ) || return } : ( $ref_value ) )";
}

1;

__END__

=pod

=head1 NAME

Moose::Meta::Method::Accessor - A Moose Method metaclass for accessors

=head1 DESCRIPTION

This is a subclass of L<Class::MOP::Method::Accessor> and it's primary
responsibility is to generate the accessor methods for attributes. It
can handle both closure based accessors, as well as inlined source based
accessors.

This is a fairly new addition to the MOP, but this will play an important
role in the optimization strategy we are currently following.

=head1 METHODS

=over 4

=item B<generate_accessor_method>

=item B<generate_reader_method>

=item B<generate_writer_method>

=item B<generate_accessor_method_inline>

=item B<generate_reader_method_inline>

=item B<generate_writer_method_inline>

=back

=head1 BUGS

All complex software has bugs lurking in it, and this module is no
exception. If you find a bug please either email me, or add the bug
to cpan-RT.

=head1 AUTHOR

Stevan Little E<lt>stevan@iinteractive.comE<gt>

Yuval Kogman E<lt>nothingmuch@woobling.comE<gt>

=head1 COPYRIGHT AND LICENSE

Copyright 2006, 2007 by Infinity Interactive, Inc.

L<http://www.iinteractive.com>

This library is free software; you can redistribute it and/or modify
it under the same terms as Perl itself.

=cut