statement.rb in rdf-0.2.0

- old
+ new

@@ -16,64 +16,75 @@
   #     :subject   => RDF::URI.new("http://rubygems.org/gems/rdf"),
   #     :predicate => RDF::DC.creator,
   #     :object    => RDF::URI.new("http://ar.to/#self"),
   #   })
   #
-  class Statement < Value
+  class Statement
+    include RDF::Value
+
     # @return [Object]
     attr_accessor :id
 
-    # @return [Resource]
+    # @return [RDF::Resource]
     attr_accessor :context
 
-    # @return [Resource]
+    # @return [RDF::Resource]
     attr_accessor :subject
 
-    # @return [URI]
+    # @return [RDF::URI]
     attr_accessor :predicate
 
-    # @return [Value]
+    # @return [RDF::Value]
     attr_accessor :object
 
     ##
     # @overload initialize(options = {})
     #   @param  [Hash{Symbol => Object}] options
-    #   @option options [Resource]       :subject   (nil)
-    #   @option options [URI]            :predicate (nil)
-    #   @option options [Value]          :object    (nil)
-    #   @option options [Resource]       :context   (nil)
+    #   @option options [RDF::Resource]  :subject   (nil)
+    #   @option options [RDF::URI]       :predicate (nil)
+    #   @option options [RDF::Value]     :object    (nil)
+    #   @option options [RDF::Resource]  :context   (nil)
     #
     # @overload initialize(subject, predicate, object, options = {})
-    #   @param  [Resource]               subject
-    #   @param  [URI]                    predicate
-    #   @param  [Value]                  object
+    #   @param  [RDF::Resource]          subject
+    #   @param  [RDF::URI]               predicate
+    #   @param  [RDF::Value]             object
     #   @param  [Hash{Symbol => Object}] options
-    #   @option options [Resource]       :context   (nil)
+    #   @option options [RDF::Resource]  :context   (nil)
     def initialize(subject = nil, predicate = nil, object = nil, options = {})
-      options = options.dup unless options.empty?
       case subject
         when Hash
-          options    = subject.dup
-          subject    = options.delete(:subject)
-          predicate  = options.delete(:predicate)
-          object     = options.delete(:object)
-          initialize(subject, predicate, object, options)
+          @options   = subject.dup
+          @subject   = @options.delete(:subject)
+          @predicate = @options.delete(:predicate)
+          @object    = @options.delete(:object)
         else
-          @id        = options.delete(:id) if options.has_key?(:id)
-          @context   = options.delete(:context) || options.delete(:graph)
-          @options   = options
+          @options   = !options.empty? ? options.dup : {}
           @subject   = subject
           @predicate = predicate
-          @object    = case object
-            when nil        then nil
-            when RDF::Value then object
-            else RDF::Literal.new(object)
-          end
+          @object    = object
       end
+      @id      = @options.delete(:id) if @options.has_key?(:id)
+      @context = @options.delete(:context) || @options.delete(:graph)
+      initialize!
     end
 
     ##
+    # @private
+    def initialize!
+      @context   = Node.intern(@context)   if @context.is_a?(Symbol)
+      @subject   = Node.intern(@subject)   if @subject.is_a?(Symbol)
+      @predicate = Node.intern(@predicate) if @predicate.is_a?(Symbol)
+      @object    = case @object
+        when nil    then nil
+        when Symbol then Node.intern(@object)
+        when Value  then @object
+        else Literal.new(@object)
+      end
+    end
+
+    ##
     # @return [Boolean]
     def invalid?
       !valid?
     end
 
@@ -165,36 +176,43 @@
       return true
     end
 
     ##
     # @param  [Integer] index
-    # @return [Value]
+    # @return [RDF::Value]
     def [](index)
-      to_a[index]
+      case index
+        when 0 then self.subject
+        when 1 then self.predicate
+        when 2 then self.object
+        when 3 then self.context
+        else nil
+      end
     end
 
     ##
-    # @param  [Integer] index
-    # @param  [Value]   value
-    # @return [Value]
+    # @param  [Integer]    index
+    # @param  [RDF::Value] value
+    # @return [RDF::Value]
     def []=(index, value)
       case index
-        when 0 then subject   = value
-        when 1 then predicate = value
-        when 2 then object    = value
-        when 3 then context   = value
+        when 0 then self.subject   = value
+        when 1 then self.predicate = value
+        when 2 then self.object    = value
+        when 3 then self.context   = value
+        else nil
       end
     end
 
     ##
-    # @return [Array(Value)]
+    # @return [Array(RDF::Value)]
     def to_quad
       [subject, predicate, object, context]
     end
 
     ##
-    # @return [Array(Value)]
+    # @return [Array(RDF::Value)]
     def to_triple
       [subject, predicate, object]
     end
 
     alias_method :to_a,   :to_triple
@@ -204,12 +222,12 @@
     # Returns the terms of this statement as a `Hash`.
     #
     # @param  [Symbol] subject_key
     # @param  [Symbol] predicate_key
     # @param  [Symbol] object_key
-    # @return [Hash{Symbol => Value}]
-    def to_hash(subject_key = :subject, predicate_key = :predicate, object_key = :object)
-      {subject_key => subject, predicate_key => predicate, object_key => object}
+    # @return [Hash{Symbol => RDF::Value}]
+    def to_hash(subject_key = :subject, predicate_key = :predicate, object_key = :object, context_key = :context)
+      {subject_key => subject, predicate_key => predicate, object_key => object, context_key => context}
     end
 
     ##
     # Returns a string representation of this statement.
     #