sum.rb in sparql-3.1.0

- old
+ new

@@ -4,16 +4,16 @@
     # The SPARQL `sum` set function.
     #
     # @example
     #    (prefix ((: <http://www.example.org/>))
     #      (project (?sum)
-    #        (extend ((?sum ?.0))
-    #          (group () ((?.0 (sum ?o)))
+    #        (extend ((?sum ??.0))
+    #          (group () ((??.0 (sum ?o)))
     #            (bgp (triple ?s :dec ?o))))))
     #
     # @see http://www.w3.org/TR/sparql11-query/#defn_aggSum
-    class Sum < Operator::Unary
+    class Sum < Operator
       include Aggregate
 
       NAME = :sum
 
       ##
@@ -21,9 +21,11 @@
       #
       # @param  [Enumerable<Array<RDF::Term>>] enum
       #   enum of evaluated operand
       # @return [RDF::Literal::Numeric] The sum of the terms
       def apply(enum)
+        # FIXME: we don't actually do anything with distinct
+        operands.shift if distinct = (operands.first == :distinct)
         if enum.empty?
           RDF::Literal(0)
         elsif enum.flatten.all? {|n| n.is_a?(RDF::Literal::Numeric)}
           enum.flatten.reduce(:+)
         else