statement.rb in rdf-2.1.1

- old
+ new

@@ -65,10 +65,11 @@
     #   @option options [RDF::URI]       :predicate (nil)
     #   @option options [RDF::Resource]      :object    (nil)
     #     if not a {Resource}, it is coerced to {Literal} or {Node} depending on if it is a symbol or something other than a {Term}.
     #   @option options [RDF::Term]  :graph_name   (nil)
     #     Note, in RDF 1.1, a graph name MUST be an {Resource}.
+    #   @option options [Boolean] :inferred used as a marker to record that this statement was inferred based on semantic relationships (T-Box).
     #   @return [RDF::Statement]
     #
     # @overload initialize(subject, predicate, object, options = {})
     #   @param  [RDF::Term]          subject
     #     A symbol is converted to an interned {Node}.
@@ -76,10 +77,11 @@
     #   @param  [RDF::Resource]              object
     #     if not a {Resource}, it is coerced to {Literal} or {Node} depending on if it is a symbol or something other than a {Term}.
     #   @param  [Hash{Symbol => Object}] options
     #   @option options [RDF::Term]  :graph_name   (nil)
     #     Note, in RDF 1.1, a graph name MUST be an {Resource}.
+    #   @option options [Boolean] :inferred used as a marker to record that this statement was inferred based on semantic relationships (T-Box).
     #   @return [RDF::Statement]
     def initialize(subject = nil, predicate = nil, object = nil, options = {})
       if subject.is_a?(Hash)
         @options   = Hash[subject] # faster subject.dup
         @subject   = @options.delete(:subject)
@@ -136,11 +138,11 @@
     # @return [Boolean]
     def variable?
       !(has_subject?    && subject.resource? &&
         has_predicate?  && predicate.resource? &&
         has_object?     && (object.resource? || object.literal?) &&
-        (has_graph?     ? graph_name.resource? : true ))
+        (has_graph?     ? graph_name.resource? : true))
     end
 
     ##
     # @return [Boolean]
     def invalid?
@@ -151,11 +153,11 @@
     # @return [Boolean]
     def valid?
       has_subject?    && subject.resource? && subject.valid? &&
       has_predicate?  && predicate.uri? && predicate.valid? &&
       has_object?     && object.term? && object.valid? &&
-      (has_graph?      ? graph_name.resource? && graph_name.valid? : true )
+      (has_graph?      ? (graph_name.resource? && graph_name.valid?) : true)
     end
 
     ##
     # @return [Boolean]
     def asserted?
@@ -169,11 +171,11 @@
     end
 
     ##
     # @return [Boolean]
     def inferred?
-      false
+      !!@options[:inferred]
     end
 
     ##
     # Determines if the statement is incomplete, vs. invalid. An incomplete statement is one in which any of `subject`, `predicate`, or `object`, are nil.
     #
@@ -240,10 +242,16 @@
     def eql?(other)
       other.is_a?(Statement) && self == other && (self.graph_name || false) == (other.graph_name || false)
     end
 
     ##
+    # Generates a Fixnum hash value as a quad.
+    def hash
+      @hash ||= to_quad.hash
+    end
+
+    ##
     # Checks statement equality as a triple.
     #
     # @param  [Object] other
     # @return [Boolean]
     #
@@ -343,9 +351,10 @@
       self.subject.canonicalize!    if has_subject? && !self.subject.frozen?
       self.predicate.canonicalize!  if has_predicate? && !self.predicate.frozen?
       self.object.canonicalize!     if has_object? && !self.object.frozen?
       self.graph_name.canonicalize! if has_graph? && !self.graph_name.frozen?
       self.validate!
+      @hash = nil
       self
     end
 
     ##
     # Returns a version of the statement with each position in canonical form