sequences emit

4 files changed, 68 insertions, 0 deletions

diff --git a/ext/psych/emitter.c b/ext/psych/emitter.c
index ce2b77e..7b8a43a 100644
--- a/ext/psych/emitter.c
+++ b/ext/psych/emitter.c
@@ -136,6 +136,43 @@ static VALUE scalar(
   return self;
 }
 
+static VALUE start_sequence(
+    VALUE self,
+    VALUE anchor,
+    VALUE tag,
+    VALUE implicit,
+    VALUE style
+) {
+  yaml_emitter_t * emitter;
+  Data_Get_Struct(self, yaml_emitter_t, emitter);
+
+  yaml_event_t event;
+  yaml_sequence_start_event_initialize(
+      &event,
+      (yaml_char_t *)(Qnil == anchor ? NULL : StringValuePtr(anchor)),
+      (yaml_char_t *)(Qnil == anchor ? NULL : StringValuePtr(tag)),
+      Qtrue == implicit ? 1 : 0,
+      (yaml_sequence_style_t)NUM2INT(style)
+  );
+
+  emit(emitter, &event);
+
+  return self;
+}
+
+static VALUE end_sequence(VALUE self)
+{
+  yaml_emitter_t * emitter;
+  Data_Get_Struct(self, yaml_emitter_t, emitter);
+
+  yaml_event_t event;
+  yaml_sequence_end_event_initialize(&event);
+
+  emit(emitter, &event);
+
+  return self;
+}
+
 void Init_psych_emitter()
 {
   VALUE psych     = rb_define_module("Psych");
@@ -150,4 +187,6 @@ void Init_psych_emitter()
   rb_define_method(cPsychEmitter, "start_document", start_document, 3);
   rb_define_method(cPsychEmitter, "end_document", end_document, 1);
   rb_define_method(cPsychEmitter, "scalar", scalar, 6);
+  rb_define_method(cPsychEmitter, "start_sequence", start_sequence, 4);
+  rb_define_method(cPsychEmitter, "end_sequence", end_sequence, 0);
 }
diff --git a/lib/psych/nodes/node.rb b/lib/psych/nodes/node.rb
index b5ae131..a63fc60 100644
--- a/lib/psych/nodes/node.rb
+++ b/lib/psych/nodes/node.rb
@@ -1,3 +1,5 @@
+require 'stringio'
+
 module Psych
   module Nodes
     ###
@@ -15,6 +17,12 @@ module Psych
       def to_ruby
         Visitors::ToRuby.new.accept self
       end
+
+      def to_yaml
+        io = StringIO.new
+        Visitors::Emitter.new(io).accept self
+        io.string
+      end
     end
   end
 end
diff --git a/lib/psych/visitors/emitter.rb b/lib/psych/visitors/emitter.rb
index e2dd0be..a0ff9d9 100644
--- a/lib/psych/visitors/emitter.rb
+++ b/lib/psych/visitors/emitter.rb
@@ -20,6 +20,12 @@ module Psych
       visitor_for(Nodes::Scalar) do |o|
         @handler.scalar o.value, o.anchor, o.tag, o.plain, o.quoted, o.style
       end
+
+      visitor_for(Nodes::Sequence) do |o|
+        @handler.start_sequence o.anchor, o.tag, o.implicit, o.style
+        o.children.each { |c| c.accept self }
+        @handler.end_sequence
+      end
     end
   end
 end
diff --git a/test/visitors/test_emitter.rb b/test/visitors/test_emitter.rb
index e2e14aa..b7b9110 100644
--- a/test/visitors/test_emitter.rb
+++ b/test/visitors/test_emitter.rb
@@ -26,6 +26,7 @@ module Psych
         @visitor.accept s
 
         assert_match(/1.1/, @io.string)
+        assert_equal @io.string, s.to_yaml
       end
 
       def test_scalar
@@ -39,9 +40,23 @@ module Psych
         @visitor.accept s
 
         assert_match(/hello/, @io.string)
+        assert_equal @io.string, s.to_yaml
       end
 
       def test_sequence
+        s       = Nodes::Stream.new
+        doc     = Nodes::Document.new
+        scalar  = Nodes::Scalar.new 'hello world'
+        seq     = Nodes::Sequence.new
+
+        seq.children << scalar
+        doc.children << seq
+        s.children << doc
+
+        @visitor.accept s
+
+        assert_match(/- hello/, @io.string)
+        assert_equal @io.string, s.to_yaml
       end
     end
   end