Add nodes for boolean constants

This is useful for dynamically created predicates e.g:

expr1 = table.create_false
expr2 = table.create_false

expr1 = create_a_predicate() if some_condition
expr2 = create_another_predicate() if some_other_condition

table.where(expr1.and(expr2))

2 files changed, 34 insertions, 0 deletions

diff --git a/lib/arel/nodes/false.rb b/lib/arel/nodes/false.rb
new file mode 100644
index 0000000000..4196070946
--- /dev/null
+++ b/lib/arel/nodes/false.rb
@@ -0,0 +1,17 @@
+module Arel
+  module Nodes
+    class False < Arel::Nodes::Node
+      def not
+        True.new
+      end
+
+      def or right
+        right
+      end
+
+      def and right
+        self
+      end
+    end
+  end
+end
diff --git a/lib/arel/nodes/true.rb b/lib/arel/nodes/true.rb
new file mode 100644
index 0000000000..82f20837f8
--- /dev/null
+++ b/lib/arel/nodes/true.rb
@@ -0,0 +1,17 @@
+module Arel
+  module Nodes
+    class True < Arel::Nodes::Node
+      def not
+        False.new
+      end
+
+      def or right
+        self
+      end
+
+      def and right
+        right
+      end
+    end
+  end
+end