1 files changed, 76 insertions, 0 deletions
diff --git a/ruby_1_9_3/lib/yaml.rb b/ruby_1_9_3/lib/yaml.rb
new file mode 100644
index 0000000000..ff9e1a6344
--- /dev/null
+++ b/ruby_1_9_3/lib/yaml.rb
@@ -0,0 +1,76 @@
+##
+# The YAML module allows you to use one of the two YAML engines that ship with
+# ruby.  By default Psych is used but the old and unmaintained Syck may be
+# chosen.
+#
+# See Psych or Syck for usage and documentation.
+#
+# To set the YAML engine to syck:
+#
+#   YAML::ENGINE.yamler = 'syck'
+#
+# To set the YAML engine back to psych:
+#
+#   YAML::ENGINE.yamler = 'psych'
+
+module YAML
+  class EngineManager # :nodoc:
+    attr_reader :yamler
+
+    def initialize
+      @yamler = nil
+    end
+
+    def syck?
+      'syck' == @yamler
+    end
+
+    def yamler= engine
+      raise(ArgumentError, "bad engine") unless %w{syck psych}.include?(engine)
+
+      require engine unless (engine == 'syck' ? Syck : Psych).const_defined?(:VERSION)
+
+      Object.class_eval <<-eorb, __FILE__, __LINE__ + 1
+        remove_const 'YAML'
+        YAML = #{engine.capitalize}
+        remove_method :to_yaml
+        alias :to_yaml :#{engine}_to_yaml
+      eorb
+
+      @yamler = engine
+      engine
+    end
+  end
+
+  ##
+  # Allows changing the current YAML engine.  See YAML for details.
+
+  ENGINE = YAML::EngineManager.new
+end
+
+if defined?(Psych)
+  engine = 'psych'
+elsif defined?(Syck)
+  engine = 'syck'
+else
+  begin
+    require 'psych'
+    engine = 'psych'
+  rescue LoadError
+    warn "#{caller[0]}:"
+    warn "It seems your ruby installation is missing psych (for YAML output)."
+    warn "To eliminate this warning, please install libyaml and reinstall your ruby."
+    require 'syck'
+    engine = 'syck'
+  end
+end
+
+module Syck
+  ENGINE = YAML::ENGINE
+end
+
+module Psych
+  ENGINE = YAML::ENGINE
+end
+
+YAML::ENGINE.yamler = engine