Mo::builder(3)

Name
Mo::builder - Adds the builder feature to Mo's has

Synopsis
    use Mo qw'builder';
    has name => ( builder => 'name_lookup' );

    sub name_lookup {
        my ($self) = @_;
        ...
    }

Description
Adds the "builder" parameter to has, which expects a method name, which is executed on $self to set the attribute if it hasn't been set yet.

Laziness
Builders in Mo are lazy by default. This can be changed by explicitly setting the "lazy" argument to false, in order to cause it to be initialized during instantiation.

    use Mo qw'builder';
    has status => ( builder => '_build_status' );             # lazy
    has source => ( builder => '_build_source', lazy => 1);   # lazy
    has target => ( builder => '_build_target', lazy => 0);   # eager

To change the default behavior and make builders to be initialized eagerly by default, import "nonlazy".

    use Mo qw'builder nonlazy';
    has status => ( builder => '_build_status' );             # eager
    has source => ( builder => '_build_source', lazy => 1);   # lazy
    has target => ( builder => '_build_target', lazy => 0);   # eager