lvalue methods in Perl

lvalue.pl

pirl @> sub hats : lvalue { my ($self) = @_; $self->{hats}; }
@var = ();
pirl @> $obj = bless {}
@var = (
         bless( {}, 'Shell::Perl::sandbox' )
       );
pirl @> $obj->hats
@var = (
         undef
       );
pirl @> $obj
@var = (
         bless( {}, 'Shell::Perl::sandbox' )
       );
pirl @> $obj->hats = 1
@var = (
         1
       );
pirl @> $obj
@var = (
         bless( {
                  'hats' => 1
                }, 'Shell::Perl::sandbox' )
       );
pirl @> $obj->hats
@var = (
         1
       );
pirl @> $obj->hats++
@var = (
         1
       );
pirl @> $obj->hats
@var = (
         2
       );
pirl @>