MooseX::AttributeHelpers::MethodProvider::List - MooseX::AttributeHelpers::MethodProvider::List documentation

MooseX-AttributeHelpers documentation Contained in the MooseX-AttributeHelpers distribution.

Index

Code Index:

NAME

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MooseX::AttributeHelpers::MethodProvider::List

SYNOPSIS

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   package Stuff;
   use Moose;
   use MooseX::AttributeHelpers;

   has 'options' => (
       metaclass  => 'Collection::List',
       is         => 'rw',
       isa        => 'ArrayRef[Str]',
       default    => sub { [] },
       auto_deref => 1,
       provides   => {
           elements => 'all_options',
           map      => 'map_options',
           grep     => 'filter_options',
           find     => 'find_option',
           first    => 'first_option',
           last     => 'last_option',
           get      => 'get_option',
           join     => 'join_options',
           count    => 'count_options',
           empty    => 'do_i_have_options',
           sort     => 'sorted_options',
       }
   );

   no Moose;
   1;

DESCRIPTION

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This is a role which provides the method generators for MooseX::AttributeHelpers::Collection::List.

METHODS

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meta

PROVIDED METHODS

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count

Returns the number of elements in the list.

   $stuff = Stuff->new;
   $stuff->options(["foo", "bar", "baz", "boo"]);

   my $count = $stuff->count_options;
   print "$count\n"; # prints 4
empty

If the list is populated, returns true. Otherwise, returns false.

   $stuff->do_i_have_options ? print "Good boy.\n" : die "No options!\n" ;
find

This method accepts a subroutine reference as its argument. That sub will receive each element of the list in turn. If it returns true for an element, that element will be returned by the find method.

   my $found = $stuff->find_option( sub { $_[0] =~ /^b/ } );
   print "$found\n"; # prints "bar"
grep

This method accepts a subroutine reference as its argument. This method returns every element for which that subroutine reference returns a true value.

   my @found = $stuff->filter_options( sub { $_[0] =~ /^b/ } );
   print "@found\n"; # prints "bar baz boo"
map

This method accepts a subroutine reference as its argument. The subroutine will be executed for each element of the list. It is expected to return a modified version of that element. The return value of the method is a list of the modified options.

   my @mod_options = $stuff->map_options( sub { $_[0] . "-tag" } );
   print "@mod_options\n"; # prints "foo-tag bar-tag baz-tag boo-tag"
sort

Sorts and returns the elements of the list.

You can provide an optional subroutine reference to sort with (as you can with the core sort function). However, instead of using $a and $b, you will need to use $_[0] and $_[1] instead.

   # ascending ASCIIbetical
   my @sorted = $stuff->sort_options();

   # Descending alphabetical order
   my @sorted_options = $stuff->sort_options( sub { lc $_[1] cmp lc $_[0] } );
   print "@sorted_options\n"; # prints "foo boo baz bar"
elements

Returns all of the elements of the list

   my @option = $stuff->all_options;
   print "@options\n"; # prints "foo bar baz boo"
join

Joins every element of the list using the separator given as argument.

   my $joined = $stuff->join_options( ':' );
   print "$joined\n"; # prints "foo:bar:baz:boo"
get

Returns an element of the list by its index.

   my $option = $stuff->get_option(1);
   print "$option\n"; # prints "bar"
first

Returns the first element of the list.

   my $first = $stuff->first_option;
   print "$first\n"; # prints "foo"
last

Returns the last element of the list.

   my $last = $stuff->last_option;
   print "$last\n"; # prints "boo"

BUGS

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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.

AUTHOR

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Stevan Little <stevan@iinteractive.com>

COPYRIGHT AND LICENSE

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Copyright 2007-2009 by Infinity Interactive, Inc.

http://www.iinteractive.com

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

MooseX-AttributeHelpers documentation Contained in the MooseX-AttributeHelpers distribution. 
package MooseX::AttributeHelpers::MethodProvider::List;
use Moose::Role;

our $VERSION   = '0.23';
$VERSION = eval $VERSION;
our $AUTHORITY = 'cpan:STEVAN';
 
sub count : method {
    my ($attr, $reader, $writer) = @_;
    return sub { 
        scalar @{$reader->($_[0])} 
    };        
}

sub empty : method {
    my ($attr, $reader, $writer) = @_;
    return sub { 
        scalar @{$reader->($_[0])} ? 1 : 0
    };        
}

sub find : method {
    my ($attr, $reader, $writer) = @_;
    return sub {
        my ($instance, $predicate) = @_;
        foreach my $val (@{$reader->($instance)}) {
            return $val if $predicate->($val);
        }
        return;
    };
}

sub map : method {
    my ($attr, $reader, $writer) = @_;
    return sub {
        my ($instance, $f) = @_;
        CORE::map { $f->($_) } @{$reader->($instance)}
    };
}

sub sort : method {
    my ($attr, $reader, $writer) = @_;
    return sub {
        my ($instance, $predicate) = @_;
        die "Argument must be a code reference"
            if $predicate && ref $predicate ne 'CODE';

        if ($predicate) {
            CORE::sort { $predicate->($a, $b) } @{$reader->($instance)};
        }
        else {
            CORE::sort @{$reader->($instance)};
        }
    };
}

sub grep : method {
    my ($attr, $reader, $writer) = @_;
    return sub {
        my ($instance, $predicate) = @_;
        CORE::grep { $predicate->($_) } @{$reader->($instance)}
    };
}

sub elements : method {
    my ($attr, $reader, $writer) = @_;
    return sub {
        my ($instance) = @_;
        @{$reader->($instance)}
    };
}

sub join : method {
    my ($attr, $reader, $writer) = @_;
    return sub {
        my ($instance, $separator) = @_;
        join $separator, @{$reader->($instance)}
    };
}

sub get : method {
    my ($attr, $reader, $writer) = @_;
    return sub {
        $reader->($_[0])->[$_[1]]
    };
}

sub first : method {
    my ($attr, $reader, $writer) = @_;
    return sub {
        $reader->($_[0])->[0]
    };
}

sub last : method {
    my ($attr, $reader, $writer) = @_;
    return sub {
        $reader->($_[0])->[-1]
    };
}

1;

__END__