8 files changed, 92 insertions, 4 deletions
diff --git a/lib/psych.rb b/lib/psych.rb
index bbb8662..3ebc1fa 100644
--- a/lib/psych.rb
+++ b/lib/psych.rb
@@ -13,6 +13,7 @@ require 'psych/visitors'
 require 'psych/handler'
 require 'psych/tree_builder'
 require 'psych/parser'
+require 'psych/ruby'
 require 'psych/psych'
 
 module Psych
@@ -22,8 +23,12 @@ module Psych
   ###
   # Load +yaml+ in to a Ruby data structure
   def self.load yaml
+    parse(yaml).to_ruby
+  end
+
+  def self.parse yaml
     parser = Psych::Parser.new(TreeBuilder.new)
     parser.parse yaml
-    parser.handler.root.children.first.to_ruby
+    parser.handler.root.children.first.children.first
   end
 end
diff --git a/lib/psych/nodes/document.rb b/lib/psych/nodes/document.rb
index be786c6..4f46644 100644
--- a/lib/psych/nodes/document.rb
+++ b/lib/psych/nodes/document.rb
@@ -10,11 +10,15 @@ module Psych
       # Was this document implicitly created?
       attr_accessor :implicit
 
+      # Is the end of the document implicit?
+      attr_accessor :implicit_end
+
       def initialize version = [], tag_directives = [], implicit = false
         super()
         @version        = version
         @tag_directives = tag_directives
         @implicit       = implicit
+        @implicit_end   = true
       end
 
       ###
diff --git a/lib/psych/nodes/node.rb b/lib/psych/nodes/node.rb
index a63fc60..6aaba15 100644
--- a/lib/psych/nodes/node.rb
+++ b/lib/psych/nodes/node.rb
@@ -17,6 +17,7 @@ module Psych
       def to_ruby
         Visitors::ToRuby.new.accept self
       end
+      alias :transform :to_ruby
 
       def to_yaml
         io = StringIO.new
diff --git a/lib/psych/ruby.rb b/lib/psych/ruby.rb
new file mode 100644
index 0000000..6802391
--- /dev/null
+++ b/lib/psych/ruby.rb
@@ -0,0 +1,13 @@
+[Object, String, Class, Hash].each do |klass|
+  klass.send(:remove_method, :to_yaml)
+end
+
+class Object
+  include Psych::Visitable
+
+  def to_yaml options = {}
+    visitor = Psych::Visitors::YASTBuilder.new options
+    visitor.accept self
+    visitor.tree.to_yaml
+  end
+end
diff --git a/lib/psych/tree_builder.rb b/lib/psych/tree_builder.rb
index efbeaf9..089ee96 100644
--- a/lib/psych/tree_builder.rb
+++ b/lib/psych/tree_builder.rb
@@ -17,7 +17,6 @@ module Psych
     end
 
     %w{
-      Document
       Sequence
       Mapping
     }.each do |node|
@@ -28,12 +27,22 @@ module Psych
           @stack.push n
         end
 
-        def end_#{node.downcase}(*args)
+        def end_#{node.downcase}
           @stack.pop
         end
       }
     end
 
+    def start_document(*args)
+      n = Nodes::Document.new(*args)
+      @stack.last.children << n
+      @stack.push n
+    end
+
+    def end_document implicit_end
+      @stack.pop.implicit_end = implicit_end
+    end
+
     def start_stream encoding
       @stack.push Nodes::Stream.new(encoding)
     end
diff --git a/lib/psych/visitors.rb b/lib/psych/visitors.rb
index df58e2e..0708e94 100644
--- a/lib/psych/visitors.rb
+++ b/lib/psych/visitors.rb
@@ -1,3 +1,4 @@
 require 'psych/visitors/visitor'
 require 'psych/visitors/to_ruby'
 require 'psych/visitors/emitter'
+require 'psych/visitors/yast_builder'
diff --git a/lib/psych/visitors/emitter.rb b/lib/psych/visitors/emitter.rb
index a0ff9d9..3e33095 100644
--- a/lib/psych/visitors/emitter.rb
+++ b/lib/psych/visitors/emitter.rb
@@ -14,7 +14,7 @@ module Psych
       visitor_for(Nodes::Document) do |o|
         @handler.start_document o.version, o.tag_directives, o.implicit
         o.children.each { |c| c.accept self }
-        @handler.end_document o.implicit
+        @handler.end_document o.implicit_end
       end
 
       visitor_for(Nodes::Scalar) do |o|
@@ -26,6 +26,16 @@ module Psych
         o.children.each { |c| c.accept self }
         @handler.end_sequence
       end
+
+      visitor_for(Nodes::Mapping) do |o|
+        @handler.start_mapping o.anchor, o.tag, o.implicit, o.style
+        o.children.each { |c| c.accept self }
+        @handler.end_mapping
+      end
+
+      visitor_for(Nodes::Alias) do |o|
+        @handler.alias o.anchor
+      end
     end
   end
 end
diff --git a/lib/psych/visitors/yast_builder.rb b/lib/psych/visitors/yast_builder.rb
new file mode 100644
index 0000000..00f533f
--- /dev/null
+++ b/lib/psych/visitors/yast_builder.rb
@@ -0,0 +1,45 @@
+module Psych
+  module Visitors
+    class YASTBuilder < Psych::Visitors::Visitor
+      attr_reader :tree
+
+      def initialize options = {}
+        super()
+        @tree = Nodes::Stream.new
+        @tree.children << Nodes::Document.new
+        @stack = @tree.children.dup
+      end
+
+      def accept target
+        target.class.ancestors.each do |klass|
+          method_name = :"visit_#{target.class.name.split('::').join('_')}"
+          if respond_to?(method_name)
+            return send(method_name, target)
+          end
+        end
+        raise TypeError, "Can't dump #{target.class}"
+      end
+
+      visitor_for(::String) do |o|
+        @stack.last.children << Nodes::Scalar.new(o)
+      end
+
+      visitor_for(::Class) do |o|
+        raise TypeError, "can't dump anonymous class #{o.class}"
+      end
+
+      visitor_for(::Hash) do |o|
+        map = Nodes::Mapping.new
+        @stack.last.children << map
+        @stack.push map
+
+        o.each do |k,v|
+          k.accept self
+          v.accept self
+        end
+
+        @stack.pop
+      end
+    end
+  end
+end