1 files changed, 16 insertions, 0 deletions
diff --git a/lib/arel/algebra/relations/operations/where.rb b/lib/arel/algebra/relations/operations/where.rb
new file mode 100644
index 0000000000..608aaeb4b7
--- /dev/null
+++ b/lib/arel/algebra/relations/operations/where.rb
@@ -0,0 +1,16 @@
+module Arel
+  class Where < Compound
+    attributes :relation, :predicate
+    deriving :==
+
+    def initialize(relation, *predicates, &block)
+      predicate = block_given?? yield(relation) : predicates.shift
+      @relation = predicates.empty?? relation : Where.new(relation, *predicates)
+      @predicate = predicate.bind(@relation)
+    end
+
+    def wheres
+      @wheres ||= (relation.wheres + [predicate]).collect { |p| p.bind(self) }
+    end
+  end
+end