3 files changed, 58 insertions, 101 deletions
diff --git a/lib/arel/algebra/predicates.rb b/lib/arel/algebra/predicates.rb
index b761eab417..5b65b59c8c 100644
--- a/lib/arel/algebra/predicates.rb
+++ b/lib/arel/algebra/predicates.rb
@@ -47,18 +47,28 @@ module Arel
           *predicates.map {|p| p.find_correlate_in(relation)}
         )
       end
+
+      def eval(row)
+        predicates.send(compounder) do |operation|
+          operation.eval(row)
+        end
+      end
     end
 
     class Any < Polyadic
       def complement
         All.new(*predicates.map {|p| p.complement})
       end
+
+      def compounder; :any? end
     end
 
     class All < Polyadic
       def complement
         Any.new(*predicates.map {|p| p.complement})
       end
+
+      def compounder; :all? end
     end
 
     class Unary < Predicate
@@ -75,12 +85,20 @@ module Arel
       def == other
         super || self.class === other && operand == other.operand
       end
+
+      def eval(row)
+        operand.eval(row).send(operator)
+      end
     end
 
     class Not < Unary
       def complement
         operand
       end
+
+      def eval(row)
+        !operand.eval(row)
+      end
     end
 
     class Binary < Unary
@@ -99,20 +117,31 @@ module Arel
       def bind(relation)
         self.class.new(operand1.find_correlate_in(relation), operand2.find_correlate_in(relation))
       end
+
+      def eval(row)
+        operand1.eval(row).send(operator, operand2.eval(row))
+      end
     end
 
-    class CompoundPredicate < Binary; end
+    class CompoundPredicate < Binary
+      def eval(row)
+        eval "operand1.eval(row) #{operator} operand2.eval(row)"
+      end
+    end
 
     class And < CompoundPredicate
       def complement
         Or.new(operand1.complement, operand2.complement)
       end
+
+      def operator; :and end
     end
 
     class Or < CompoundPredicate
       def complement
         And.new(operand1.complement, operand2.complement)
       end
+      def operator; :or end
     end
 
     class Equality < Binary
@@ -125,60 +154,88 @@ module Arel
       def complement
         Inequality.new(operand1, operand2)
       end
+
+      def operator; :== end
     end
 
     class Inequality < Equality
       def complement
         Equality.new(operand1, operand2)
       end
+
+      def eval(row)
+        operand1.eval(row) != operand2.eval(row)
+      end
     end
 
     class GreaterThanOrEqualTo < Binary
       def complement
         LessThan.new(operand1, operand2)
       end
+
+      def operator; :>= end
     end
 
     class GreaterThan < Binary
       def complement
         LessThanOrEqualTo.new(operand1, operand2)
       end
+
+      def operator; :> end
     end
 
     class LessThanOrEqualTo < Binary
       def complement
         GreaterThan.new(operand1, operand2)
       end
+
+      def operator; :<= end
     end
 
     class LessThan < Binary
       def complement
         GreaterThanOrEqualTo.new(operand1, operand2)
       end
+
+      def operator; :< end
     end
 
     class Match < Binary
       def complement
         NotMatch.new(operand1, operand2)
       end
+
+      def operator; :=~ end
     end
 
     class NotMatch < Binary
       def complement
         Match.new(operand1, operand2)
       end
+
+      def eval(row)
+        operand1.eval(row) !~ operand2.eval(row)
+      end
     end
 
     class In < Binary
       def complement
         NotIn.new(operand1, operand2)
       end
+
+      def eval(row)
+        operand2.eval(row).include?(operand1.eval(row))
+      end
     end
 
     class NotIn < Binary
       def complement
         In.new(operand1, operand2)
       end
+
+      def eval(row)
+        !(operand2.eval(row).include?(operand1.eval(row)))
+      end
     end
   end
 end
diff --git a/lib/arel/engines/memory.rb b/lib/arel/engines/memory.rb
index 9e7193ef13..5a963e8ba1 100644
--- a/lib/arel/engines/memory.rb
+++ b/lib/arel/engines/memory.rb
@@ -1,4 +1,3 @@
 require 'arel/engines/memory/relations'
 require 'arel/engines/memory/primitives'
 require 'arel/engines/memory/engine'
-require 'arel/engines/memory/predicates'
diff --git a/lib/arel/engines/memory/predicates.rb b/lib/arel/engines/memory/predicates.rb
deleted file mode 100644
index 1527b04056..0000000000
--- a/lib/arel/engines/memory/predicates.rb
+++ /dev/null
@@ -1,99 +0,0 @@
-module Arel
-  module Predicates
-    class Binary < Unary
-      def eval(row)
-        operand1.eval(row).send(operator, operand2.eval(row))
-      end
-    end
-
-    class Unary < Predicate
-      def eval(row)
-        operand.eval(row).send(operator)
-      end
-    end
-
-    class Not < Unary
-      def eval(row)
-        !operand.eval(row)
-      end
-    end
-
-    class Polyadic < Predicate
-      def eval(row)
-        predicates.send(compounder) do |operation|
-          operation.eval(row)
-        end
-      end
-    end
-
-    class Any < Polyadic
-      def compounder; :any? end
-    end
-
-    class All < Polyadic
-      def compounder; :all? end
-    end
-
-    class CompoundPredicate < Binary
-      def eval(row)
-        eval "operand1.eval(row) #{operator} operand2.eval(row)"
-      end
-    end
-
-    class Or < CompoundPredicate
-      def operator; :or end
-    end
-
-    class And < CompoundPredicate
-      def operator; :and end
-    end
-
-    class Equality < Binary
-      def operator; :== end
-    end
-
-    class Inequality < Equality
-      def eval(row)
-        operand1.eval(row) != operand2.eval(row)
-      end
-    end
-
-    class GreaterThanOrEqualTo < Binary
-      def operator; :>= end
-    end
-
-    class GreaterThan < Binary
-      def operator; :> end
-    end
-
-    class LessThanOrEqualTo < Binary
-      def operator; :<= end
-    end
-
-    class LessThan < Binary
-      def operator; :< end
-    end
-
-    class Match < Binary
-      def operator; :=~ end
-    end
-
-    class NotMatch < Binary
-      def eval(row)
-        operand1.eval(row) !~ operand2.eval(row)
-      end
-    end
-
-    class In < Binary
-      def eval(row)
-        operand2.eval(row).include?(operand1.eval(row))
-      end
-    end
-
-    class NotIn < Binary
-      def eval(row)
-        !(operand2.eval(row).include?(operand1.eval(row)))
-      end
-    end
-  end
-end