using a NilClass cache to improve performance

fixed a bug where nil is returned instead of false

lib/using_yaml.rb

@@ -21,6 +21,8 @@
 #
 # See +using_yaml+ for usage information.
 module UsingYAML
+  NilClass = add_nilclass_extensions(nil, nil)
+
   class << self
     # Extends the incoming Array/Hash with magic which makes it
     # possible to +save+ and (in the case of Hashes) use methods
@@ -31,10 +33,14 @@ def add_extensions(object, pathname = nil)
         add_array_extensions(object, pathname)
       when Hash
         add_hash_extensions(object, pathname)
-      when NilClass
-        add_nilclass_extensions(object, pathname)
+      when ::NilClass
+        if pathname
+          add_nilclass_extensions(object, pathname)
+        else
+          UsingYAML::NilClass
+        end
       end
-
+            
       object
     end
 
@@ -142,7 +148,7 @@ def using_yaml_file(filename)
           @using_yaml_cache[pathname] = UsingYAML.add_extensions(YAML.load_file(pathname), pathname)
         rescue Exception => e
           $stderr.puts "(UsingYAML) Could not load #{filename}: #{e.message}" unless UsingYAML.squelched?
-          UsingYAML.add_extensions(nil)
+          @using_yaml_cache[pathname] = UsingYAML.add_extensions(nil, pathname)
         end
       end
 

lib/using_yaml/array.rb

@@ -25,5 +25,6 @@ def self.add_array_extensions(array, pathname)
 
     # Load in the extensions for this instance
     array.extend(extensions)
+    array
   end
 end

lib/using_yaml/hash.rb

@@ -13,7 +13,8 @@ def self.add_hash_extensions(hash, pathname)
         name = args.shift.to_s
 
         if args.empty?
-          send(:[], name) || UsingYAML.add_extensions(nil)
+          value = send(:[], name)
+          value.nil? ? UsingYAML::NilClass : value
         elsif args.size == 1 && name =~ /(.+)=/
           # This is an "alias" turning self.key= into self[key]=
           # Also extends the incoming value so that it behaves
@@ -53,5 +54,6 @@ def self.add_hash_extensions(hash, pathname)
 
     # Load in the extensions for this instance
     hash.extend(extensions)
+    hash
   end
 end

lib/using_yaml/nilclass.rb

@@ -1,10 +1,10 @@
 module UsingYAML
   def self.add_nilclass_extensions(instance, pathname)
     extensions = Module.new do
-      define_method(:method_missing) do
+      define_method(:method_missing) do |*args|
         # Child objects should not have #save
         if respond_to? :save
-          add_extensions(nil)
+          UsingYAML::NilClass
         else
           # One nil is the same as the next :)
           self
@@ -29,5 +29,6 @@ def self.add_nilclass_extensions(instance, pathname)
     end
 
     instance.extend(extensions)
+    instance
   end
 end

spec/using_yaml/using_yaml_spec.rb

@@ -11,7 +11,12 @@
     end
 
     it "should gracefully handle nil.nil..." do
-      @person.children.invalid.call.should be_nil
+      @person.children.something.invalid.should be_nil
+    end
+
+    it "should return false when expected" do
+      YAML.stubs(:load_file).with(anything).returns({ 'example' => false })
+      @person.children.example.should == false
     end
   end