NAME
    Devel::Declare - Adding keywords to perl, in perl

SYNOPSIS
      use Devel::Declare ();
      
  {
        package MethodHandlers;
      
    use strict;
        use warnings;
        use B::Hooks::EndOfScope;
      
    our ($Declarator, $Offset);
      
    sub skip_declarator {
          $Offset += Devel::Declare::toke_move_past_token($Offset);
        }
      
    sub skipspace {
          $Offset += Devel::Declare::toke_skipspace($Offset);
        }
      
    sub strip_name {
          skipspace;
          if (my $len = Devel::Declare::toke_scan_word($Offset, 1)) {
            my $linestr = Devel::Declare::get_linestr();
            my $name = substr($linestr, $Offset, $len);
            substr($linestr, $Offset, $len) = '';
            Devel::Declare::set_linestr($linestr);
            return $name;
          }
          return;
        }
      
    sub strip_proto {
          skipspace;
          
      my $linestr = Devel::Declare::get_linestr();
          if (substr($linestr, $Offset, 1) eq '(') {
            my $length = Devel::Declare::toke_scan_str($Offset);
            my $proto = Devel::Declare::get_lex_stuff();
            Devel::Declare::clear_lex_stuff();
            $linestr = Devel::Declare::get_linestr();
            substr($linestr, $Offset, $length) = '';
            Devel::Declare::set_linestr($linestr);
            return $proto;
          }
          return;
        }
      
    sub shadow {
          my $pack = Devel::Declare::get_curstash_name;
          Devel::Declare::shadow_sub("${pack}::${Declarator}", $_[0]);
        }
      
    # undef  -> my ($self) = shift;
        # ''     -> my ($self) = @_;
        # '$foo' -> my ($self, $foo) = @_;
      
    sub make_proto_unwrap {
          my ($proto) = @_;
          my $inject = 'my ($self';
          if (defined $proto) {
            $inject .= ", $proto" if length($proto);
            $inject .= ') = @_; ';
          } else {
            $inject .= ') = shift;';
          }
          return $inject;
        }
      
    sub inject_if_block {
          my $inject = shift;
          skipspace;
          my $linestr = Devel::Declare::get_linestr;
          if (substr($linestr, $Offset, 1) eq '{') {
            substr($linestr, $Offset+1, 0) = $inject;
            Devel::Declare::set_linestr($linestr);
          }
        }

        sub scope_injector_call {
          return ' BEGIN { MethodHandlers::inject_scope }; ';
        }
      
    sub parser {
          local ($Declarator, $Offset) = @_;
          skip_declarator;
          my $name = strip_name;
          my $proto = strip_proto;
          my $inject = make_proto_unwrap($proto);
          if (defined $name) {
            $inject = scope_injector_call().$inject;
          }
          inject_if_block($inject);
          if (defined $name) {
            $name = join('::', Devel::Declare::get_curstash_name(), $name)
              unless ($name =~ /::/);
            shadow(sub (&) { no strict 'refs'; *{$name} = shift; });
          } else {
            shadow(sub (&) { shift });
          }
        }
      
    sub inject_scope {
          on_scope_end {
            my $linestr = Devel::Declare::get_linestr;
            my $offset = Devel::Declare::get_linestr_offset;
            substr($linestr, $offset, 0) = ';';
            Devel::Declare::set_linestr($linestr);
          };
        }
      }
      
  my ($test_method1, $test_method2, @test_list);
      
  {
        package DeclareTest;
      
    sub method (&);
      
    BEGIN {
          Devel::Declare->setup_for(
            __PACKAGE__,
            { method => { const => \&MethodHandlers::parser } }
          );
        }
      
    method new {
          my $class = ref $self || $self;
          return bless({ @_ }, $class);
        }
      
    method foo ($foo) {
          return (ref $self).': Foo: '.$foo;
        }
      
    method upgrade(){ # no spaces to make case pathological
          bless($self, 'DeclareTest2');
        }
      
    method DeclareTest2::bar () {
          return 'DeclareTest2: bar';
        }
      
    $test_method1 = method {
          return join(', ', $self->{attr}, $_[1]);
        };
      
    $test_method2 = method ($what) {
          return join(', ', ref $self, $what);
        };
      
    method main () { return "main"; }
      
    @test_list = (method { 1 }, sub { 2 }, method () { 3 }, sub { 4 });
      
  }
      
  use Test::More 'no_plan';
      
  my $o = DeclareTest->new(attr => "value");
      
  isa_ok($o, 'DeclareTest');
      
  is($o->{attr}, 'value', '@_ args ok');
      
  is($o->foo('yay'), 'DeclareTest: Foo: yay', 'method with argument ok');
      
  is($o->main, 'main', 'declaration of package named method ok');
      
  $o->upgrade;
      
  isa_ok($o, 'DeclareTest2');
      
  is($o->bar, 'DeclareTest2: bar', 'absolute method declaration ok');
      
  is($o->$test_method1('no', 'yes'), 'value, yes', 'anon method with @_ ok');
      
  is($o->$test_method2('this'), 'DeclareTest2, this', 'anon method with proto ok');
      
  is_deeply([ map { $_->() } @test_list ], [ 1, 2, 3, 4], 'binding ok');

    (this is t/method-no-semi.t in this distribution)

DESCRIPTION
  setup_for
      Devel::Declare->setup_for(
        $package,
        {
          $name => { $op_type => $sub }
        }
      );

    Currently valid op types: 'check', 'rv2cv'

AUTHORS
    Matt S Trout - <mst@shadowcat.co.uk>

    Company: http://www.shadowcat.co.uk/ Blog: http://chainsawblues.vox.com/

    Florian Ragwitz <rafl@debian.org>

LICENSE
    This library is free software under the same terms as perl itself

