1 files changed, 44 insertions, 0 deletions
diff --git a/lib/Tree/Transform.pm b/lib/Tree/Transform.pm
index 99cc07f..7b9af2c 100644
--- a/lib/Tree/Transform.pm
+++ b/lib/Tree/Transform.pm
@@ -1,8 +1,52 @@
 package Tree::Transform;
 use Moose;
+use Sub::Exporter;
+use Params::Validate ':all';
 
 our $VERSION='0.1';
 
+Sub::Exporter::setup_exporter({
+    exports => [qw(tree_rule new_transformer)],
+    groups => {
+        default => [ 'tree_rule',
+                     'new_transformer' => {-as => 'new'} ],
+    }
+});
+
+sub _rules_store {
+    no strict 'refs';
+    if (!defined *{$_[0].'::_tree_transform_rules'}{HASH}) {
+        *{$_[0].'::_tree_transform_rules'}={};
+    }
+    return *{$_[0].'::_tree_transform_rules'}{HASH};
+}
+
+sub tree_rule {
+    my (%args)=validate(@_, {
+        match => { type => SCALAR, optional => 1 },
+        action => { type => CODEREF },
+        name => { type => SCALAR, optional => 1},
+        priority => { type => SCALAR, default => 1 },
+    });
+
+    # TODO at least one of 'name' and 'match' must be specified
+
+    my $store=_rules_store(scalar caller);
+
+    push @{$store->{by_match}},\%args;
+    if ($args{name}) {
+        push @{$store->{by_name}{$args{name}}},\%args;
+    }
+
+    return;
+}
+
+sub new_transformer {
+}
+
+__PACKAGE__->meta->make_immutable;no Moose;
+__END__
+
 =head1 NAME
 
 Tree::Transform - transform tree data, like XSLT but in Perl