statement.rb in rdf-0.1.0

- old
+ new

@@ -1,21 +1,21 @@
 module RDF
   ##
   # An RDF statement.
   #
   # @example Creating an RDF statement
-  #   s = RDF::URI.new("http://gemcutter.org/gems/rdf")
+  #   s = RDF::URI.new("http://rubygems.org/gems/rdf")
   #   p = RDF::DC.creator
   #   o = RDF::URI.new("http://ar.to/#self")
   #   RDF::Statement.new(s, p, o)
   #
   # @example Creating an RDF statement with a context
   #   RDF::Statement.new(s, p, o, :context => uri)
   #
   # @example Creating an RDF statement from a `Hash`
   #   RDF::Statement.new({
-  #     :subject   => RDF::URI.new("http://gemcutter.org/gems/rdf"),
+  #     :subject   => RDF::URI.new("http://rubygems.org/gems/rdf"),
   #     :predicate => RDF::DC.creator,
   #     :object    => RDF::URI.new("http://ar.to/#self"),
   #   })
   #
   class Statement < Value
@@ -60,11 +60,15 @@
           @id        = options.delete(:id) if options.has_key?(:id)
           @context   = options.delete(:context) || options.delete(:graph)
           @options   = options
           @subject   = subject
           @predicate = predicate
-          @object    = object
+          @object    = case object
+            when nil        then nil
+            when RDF::Value then object
+            else RDF::Literal.new(object)
+          end
       end
     end
 
     ##
     # @return [Boolean]
@@ -204,16 +208,28 @@
     def to_hash(subject_key = :subject, predicate_key = :predicate, object_key = :object)
       {subject_key => subject, predicate_key => predicate, object_key => object}
     end
 
     ##
+    # Returns a string representation of this statement.
+    #
     # @return [String]
     def to_s
       require 'stringio' unless defined?(StringIO)
       StringIO.open do |buffer|
-        buffer << "<#{subject}> "
-        buffer << "<#{predicate}> "
-        buffer << "<#{object}> ."
+        buffer << case subject
+          when RDF::Node    then subject.to_s
+          when RDF::URI     then "<#{subject}>"
+          else subject.inspect
+        end
+        buffer << " <#{predicate}> "
+        buffer << case object
+          when RDF::Literal then object.to_s
+          when RDF::Node    then object.to_s
+          when RDF::URI     then "<#{object}>"
+          else object.inspect
+        end
+        buffer << " ."
         buffer.string
       end
     end
   end
 end