options are being used, :canonical and :indentation are supported

7 files changed, 60 insertions, 8 deletions

diff --git a/ext/psych/emitter.c b/ext/psych/emitter.c
index 0400f7e..189b865 100644
--- a/ext/psych/emitter.c
+++ b/ext/psych/emitter.c
@@ -435,7 +435,8 @@ static VALUE canonical(VALUE self)
 
 /* call-seq: emitter.indentation = level
  *
- * Set the indentation level to +level+.
+ * Set the indentation level to +level+.  The level must be less than 10 and
+ * greater than 1.
  */
 static VALUE set_indentation(VALUE self, VALUE level)
 {
diff --git a/lib/psych.rb b/lib/psych.rb
index c1feff8..ba4a683 100644
--- a/lib/psych.rb
+++ b/lib/psych.rb
@@ -155,11 +155,29 @@ module Psych
   end
 
   ###
-  # Dump Ruby object +o+ to a YAML string using +options+.
+  # call-seq:
+  #   Psych.dump(o)               -> string of yaml
+  #   Psych.dump(o, options)      -> string of yaml
+  #   Psych.dump(o, io)           -> io object passed in
+  #   Psych.dump(o, io, options)  -> io object passed in
+  #
+  # Dump Ruby object +o+ to a YAML string.  Optional +options+ may be passed in
+  # to control the output format.  If an IO object is passed in, the YAML will
+  # be dumped to that IO object.
   #
   # Example:
   #
+  #   # Dump an array, get back a YAML string
   #   Psych.dump(['a', 'b'])  # => "---\n- a\n- b\n"
+  #
+  #   # Dump an array to an IO object
+  #   Psych.dump(['a', 'b'], StringIO.new)  # => #<StringIO:0x000001009d0890>
+  #
+  #   # Dump an array with indentation set
+  #   Psych.dump(['a', ['b']], :indentation => 3) # => "---\n- a\n-  - b\n"
+  #
+  #   # Dump an array to an IO with indentation set
+  #   Psych.dump(['a', ['b']], StringIO.new, :indentation => 3)
   def self.dump o, io = nil, options = {}
     if Hash === io
       options = io
@@ -168,7 +186,7 @@ module Psych
 
     visitor = Psych::Visitors::YAMLTree.new options
     visitor << o
-    visitor.tree.to_yaml io
+    visitor.tree.to_yaml io, options
   end
 
   ###
diff --git a/lib/psych/core_ext.rb b/lib/psych/core_ext.rb
index 8d3e8fb..be26b2f 100644
--- a/lib/psych/core_ext.rb
+++ b/lib/psych/core_ext.rb
@@ -6,9 +6,10 @@ class Object
   # FIXME: rename this to "to_yaml" when syck is removed
 
   ###
-  # call-seq: to_yaml
+  # call-seq: to_yaml(options = {})
   #
-  # Convert an object to YAML
+  # Convert an object to YAML.  See Psych.dump for more information on the
+  # available +options+.
   def psych_to_yaml options = {}
     Psych.dump self, options
   end
diff --git a/lib/psych/nodes/node.rb b/lib/psych/nodes/node.rb
index 3ab9aca..bfd91f9 100644
--- a/lib/psych/nodes/node.rb
+++ b/lib/psych/nodes/node.rb
@@ -30,10 +30,10 @@ module Psych
       # Convert this node to YAML.
       #
       # See also Psych::Visitors::Emitter
-      def to_yaml io = nil
+      def to_yaml io = nil, options = {}
         real_io = io || StringIO.new
 
-        Visitors::Emitter.new(real_io).accept self
+        Visitors::Emitter.new(real_io, options).accept self
         return real_io.string unless io
         io
       end
diff --git a/lib/psych/visitors/emitter.rb b/lib/psych/visitors/emitter.rb
index 0768fbb..c84629f 100644
--- a/lib/psych/visitors/emitter.rb
+++ b/lib/psych/visitors/emitter.rb
@@ -1,8 +1,10 @@
 module Psych
   module Visitors
     class Emitter < Psych::Visitors::Visitor
-      def initialize io
+      def initialize io, options = {}
         @handler = Psych::Emitter.new io
+        @handler.indentation = options[:indentation] if options[:indentation]
+        @handler.canonical = options[:canonical] if options[:canonical]
       end
 
       def visit_Psych_Nodes_Stream o
diff --git a/test/psych/test_psych.rb b/test/psych/test_psych.rb
index 0d33cb1..f3f3a53 100644
--- a/test/psych/test_psych.rb
+++ b/test/psych/test_psych.rb
@@ -8,6 +8,16 @@ class TestPsych < Psych::TestCase
     Psych.domain_types.clear
   end
 
+  def test_indent
+    yml = Psych.dump({:a => {'b' => 'c'}}, {:indentation => 5})
+    assert_match(/^[ ]{5}b/, yml)
+  end
+
+  def test_canonical
+    yml = Psych.dump({:a => {'b' => 'c'}}, {:canonical => true})
+    assert_match(/\? ! "b/, yml)
+  end
+
   def test_load_argument_error
     assert_raises(TypeError) do
       Psych.load nil
diff --git a/test/psych/visitors/test_emitter.rb b/test/psych/visitors/test_emitter.rb
index bdae1bd..7847cea 100644
--- a/test/psych/visitors/test_emitter.rb
+++ b/test/psych/visitors/test_emitter.rb
@@ -9,6 +9,26 @@ module Psych
         @visitor = Visitors::Emitter.new @io
       end
 
+      def test_options
+        io = StringIO.new
+        visitor = Visitors::Emitter.new io, :indentation => 3
+
+        s       = Nodes::Stream.new
+        doc     = Nodes::Document.new
+        mapping = Nodes::Mapping.new
+        m2      = Nodes::Mapping.new
+        m2.children << Nodes::Scalar.new('a')
+        m2.children << Nodes::Scalar.new('b')
+
+        mapping.children << Nodes::Scalar.new('key')
+        mapping.children << m2
+        doc.children << mapping
+        s.children << doc
+
+        visitor.accept s
+        assert_match(/^[ ]{3}a/, io.string)
+      end
+
       def test_stream
         s = Nodes::Stream.new
         @visitor.accept s