--- /dev/null
+package Filter::Keyword;
+
+use Package::Stash::PP;
+use Filter::Util::Call;
+use B qw(svref_2object);
+use Moo;
+
+has target_package => (is => 'ro', required => 1);
+
+has stash => (is => 'lazy');
+
+sub _build_stash {
+ my ($self) = @_;
+ Package::Stash::PP->new($self->target_package);
+}
+
+has keyword_name => (is => 'ro', required => 1);
+
+has globref => (is => 'lazy', clearer => 'clear_globref');
+
+sub _build_globref {
+ no strict 'refs'; no warnings 'once';
+ \*{join'::',$_[0]->target_package,$_[0]->keyword_name}
+}
+
+after clear_globref => sub {
+ my ($self) = @_;
+ $self->stash->remove_symbol('&'.$self->keyword_name);
+ $self->globref_refcount(undef);
+};
+
+has globref_refcount => (is => 'rw');
+
+sub save_refcount {
+ my ($self) = @_;
+ warn "Save: ".$self->globref_refcount(svref_2object($self->globref)->REFCNT);
+}
+
+sub refcount_changed {
+ my ($self) = @_;
+ return 0 unless defined($self->globref_refcount);
+ svref_2object($self->globref)->REFCNT > $self->globref_refcount;
+}
+
+has info => (is => 'rw', predicate => 'has_info', clearer => 'clear_info');
+
+sub setup {
+ my ($self) = @_;
+ $self->globref;
+ filter_add($self);
+}
+
+my $name_re = '[A-Za-z][A-Za-z_0-9]*';
+
+sub filter {
+ my ($self) = @_;
+ if ($self->has_info) {
+ if (delete $self->info->{first}) {
+ warn "Attempting short circuit";
+ filter_add($self);
+ return 0;
+ }
+ my $info = $self->clear_info;
+ $_ = $info->{rest};
+ if ($self->refcount_changed) {
+ warn "Trapped: ".$info->{name};
+ my $name = $info->{name};
+ ${$info->{inner}} = sub { warn "Define ${name}" };
+ #$self->clear_globref;
+ s/{/; sub ${\$info->{name}} { my \$self = shift;/;
+ }
+warn "Line: $_";
+ return 1;
+ }
+ my $status = filter_read();
+warn "Line: $_";
+ my $kw = $self->keyword_name;
+ if (/(.*?$kw\s+(${name_re}))(.*)\Z/s) {
+ my ($start, $name, $rest) = ($1, $2, $3);
+ $self->clear_globref if $self->refcount_changed;
+ no warnings 'redefine';
+ my $inner = sub {};
+ *{$self->globref} = sub (*;@) { $inner->(@_) };
+ $self->save_refcount;
+ $_ = $start;
+ $self->info({
+ name => $name, rest => $rest, first => 1,
+ inner => \$inner
+ });
+ return 1;
+ }
+ return $status;
+}
+
+1;
--- /dev/null
+use strictures 1;
+use Test::More qw(no_plan);
+use Filter::Keyword;
+
+BEGIN {
+ (our $Kw = Filter::Keyword->new(
+ target_package => __PACKAGE__,
+ keyword_name => 'method'
+ ))->setup;
+}
+
+method main { 'YAY '.$self };
+
+my $x = "method foo bar baz";
+
+method spoon { 'I HAZ A SPOON'};
+
+warn __PACKAGE__->main;
+warn __PACKAGE__->spoon;