/ 
accessors-0.02
River stage two • 16 direct dependents • 47 total dependents
/ accessors

NAME

accessors - create accessor methods in caller's package.

SYNOPSIS

package Foo;
use accessors qw( foo bar baz );

my $obj = bless {}, 'Foo';

# generates chaining accessors:
$obj->foo( 'hello ' )
    ->bar( 'world' )
    ->baz( "!\n" );

print $obj->foo, $obj->bar, $obj->baz;

DESCRIPTION

The accessors pragma lets you create simple accessors at compile-time.

This saves you from writing them by hand, which tends to result in cut-n-paste errors and a mess of duplicated code. It can also help you reduce the ammount of unwanted direct-variable access that may creep into your codebase when you're feeling lazy. accessors was designed with laziness in mind.

Method-chaining accessors are generated by default. This may be changed in future versions! If you want backwards compatability use accessors::chained and wait until the dust settles.

See accessors::classic for accessors that always return the current value if you don't like method chaining.

GENERATED METHODS

accessors will generate methods that return the current object on set:

sub foo {
    my $self = shift;
    if (@_) { $self->{-foo} = shift; return $self; }
    else    { return $self->{-foo}; }
}

This way they can be chained together.

PERFORMANCE

There is little-to-no performace hit when using generated accessors; in fact there is usually a performance gain.

  • typically 10-30% faster than hard-coded accessors (like the above example).

  • typically 1-15% slower than optimized accessors (less readable).

  • typically a small performance hit at startup (accessors are created at compile-time).

  • uses the same anonymous sub to reduce memory consumption (sometimes by 80%).

See the benchmark tests included with this distribution for more details.

MOTIVATION

The main difference between the accessors pragma and other accessor generators is simplicity.

  • interface

    use accessors qw( ... ) is as easy as it gets.

  • a pragma

    it fits in nicely with the base pragma:

    use base      qw( Some::Class );
use accessors qw( foo bar baz );

    and accessors get created at compile-time.

  • no bells and whistles

    The module is extensible instead.

SUB-CLASSING

If you prefer a different style of accessor or you need to do something more complicated, there's nothing to stop you from sub-classing. Look through accessors::classic to start.

CAVEATS

Classes using blessed scalars or arrays are not supported.

THANKS

Thanks to Michael G. Schwern for indirectly inspiring this module, and for his feedback & suggestions.

Also to Paul Makepeace and David Wright for showing me faster accessors, and to James Duncan and people on London.pm for their feedback.

AUTHOR

Steve Purkis <spurkis@epn.nu>

SEE ALSO

accessors::classic, accessors::chained

Similar and related modules:

base, fields, Class::Accessor, Class::Struct, Class::Methodmaker, Class::Generate, Class::Class, Class::Tangram