Changed RDF::Enumerable#{statements,triples,quads,subjects,predicates…

…,objects,contexts} to return enumerators instead of arrays.

Pervasively using enumerators instead of arrays facilitates dealing with larger resultsets, enabling optimizations for both memory usage and (in the case of remote repositories) bandwidth utilization.

If you really need the previous behavior of an array result, you need simply call #to_a on the returned enumerator object.

lib/rdf/mixin/enumerable.rb

@@ -86,11 +86,11 @@ def count
     # Returns all RDF statements.
     #
     # @param  [Hash{Symbol => Boolean}] options
-    # @return [Array<Statement>]
+    # @return [Enumerator<Statement>]
     # @see    #each_statement
     # @see    #enum_statement
     def statements(options = {})
-      enum_statement.to_a
+      enum_statement
     end
 
     ##
@@ -143,11 +143,11 @@ def enum_statement
     # Returns all RDF triples.
     #
     # @param  [Hash{Symbol => Boolean}] options
-    # @return [Array<Array(Resource, URI, Value)>]
+    # @return [Enumerator<Array(Resource, URI, Value)>]
     # @see    #each_triple
     # @see    #enum_triple
     def triples(options = {})
-      enum_statement.map { |statement| statement.to_triple }
+      enum_statement.map { |statement| statement.to_triple }.to_enum # TODO: optimize
     end
 
     ##
@@ -203,11 +203,11 @@ def enum_triple
     # Returns all RDF quads.
     #
     # @param  [Hash{Symbol => Boolean}] options
-    # @return [Array<Array(Resource, URI, Value, Resource)>]
+    # @return [Enumerator<Array(Resource, URI, Value, Resource)>]
     # @see    #each_quad
     # @see    #enum_quad
     def quads(options = {})
-      enum_statement.map { |statement| statement.to_quad }
+      enum_statement.map { |statement| statement.to_quad }.to_enum # TODO: optimize
     end
 
     ##
@@ -265,14 +265,14 @@ def enum_quad
     #
     # @param  [Hash{Symbol => Boolean}] options
     # @option options [Boolean] :unique (true)
-    # @return [Array<Resource>]
+    # @return [Enumerator<Resource>]
     # @see    #each_subject
     # @see    #enum_subject
     def subjects(options = {})
       if options[:unique] == false
-        enum_statement.map { |statement| statement.subject }
+        enum_statement.map { |statement| statement.subject }.to_enum # TODO: optimize
       else
-        enum_subject.to_a
+        enum_subject
       end
     end
 
@@ -333,14 +333,14 @@ def enum_subject
     #
     # @param  [Hash{Symbol => Boolean}] options
     # @option options [Boolean] :unique (true)
-    # @return [Array<URI>]
+    # @return [Enumerator<URI>]
     # @see    #each_predicate
     # @see    #enum_predicate
     def predicates(options = {})
       if options[:unique] == false
-        enum_statement.map { |statement| statement.predicate }
+        enum_statement.map { |statement| statement.predicate }.to_enum # TODO: optimize
       else
-        enum_predicate.to_a
+        enum_predicate
       end
     end
 
@@ -401,14 +401,14 @@ def enum_predicate
     #
     # @param  [Hash{Symbol => Boolean}] options
     # @option options [Boolean] :unique (true)
-    # @return [Array<Value>]
+    # @return [Enumerator<Value>]
     # @see    #each_object
     # @see    #enum_object
     def objects(options = {})
       if options[:unique] == false
-        enum_statement.map { |statement| statement.object }
+        enum_statement.map { |statement| statement.object }.to_enum # TODO: optimize
       else
-        enum_object.to_a
+        enum_object
       end
     end
 
@@ -469,14 +469,14 @@ def enum_object
     #
     # @param  [Hash{Symbol => Boolean}] options
     # @option options [Boolean] :unique (true)
-    # @return [Array<Resource>]
+    # @return [Enumerator<Resource>]
     # @see    #each_context
     # @see    #enum_context
     def contexts(options = {})
       if options[:unique] == false
-        enum_statement.map { |statement| statement.context }
+        enum_statement.map { |statement| statement.context }.to_enum # TODO: optimize
       else
-        enum_context.to_a
+        enum_context
       end
     end