1 files changed, 75 insertions, 6 deletions

diff --git a/lib/sqlalchemy/dialects/postgresql/ranges.py b/lib/sqlalchemy/dialects/postgresql/ranges.py
index b3a670d91..2054ef137 100644
--- a/lib/sqlalchemy/dialects/postgresql/ranges.py
+++ b/lib/sqlalchemy/dialects/postgresql/ranges.py
@@ -8,42 +8,111 @@ from ... import types as sqltypes
 
 __all__ = ('INT4RANGE', 'INT8RANGE', 'NUMRANGE')
 
-class INT4RANGE(sqltypes.TypeEngine):
+class RangeOperators(object):
+
+    class comparator_factory(sqltypes.Concatenable.Comparator):
+        """Define comparison operations for range types."""
+
+        def __ne__(self, other):
+            "Boolean expression. Returns true if two ranges are not equal" 
+            return self.expr.op('<>')(other)
+
+        def contains(self, other, **kw):
+            """Boolean expression. Returns true if the right hand operand,
+            which can be an element or a range, is contained within the
+            column.
+            """
+            return self.expr.op('@>')(other)
+
+        def contained_by(self, other):
+            """Boolean expression. Returns true if the column is contained
+            within the right hand operand.
+            """
+            return self.expr.op('<@')(other)
+
+        def overlaps(self, other):
+            """Boolean expression. Returns true if the column overlaps
+            (has points in common with) the right hand operand.
+            """
+            return self.expr.op('&&')(other)
+
+        def strictly_left_of(self, other):
+            """Boolean expression. Returns true if the column is strictly
+            left of the right hand operand.
+            """
+            return self.expr.op('<<')(other)
+            
+        __lshift__ = strictly_left_of
+
+        def strictly_right_of(self, other):
+            """Boolean expression. Returns true if the column is strictly
+            right of the right hand operand.
+            """
+            return self.expr.op('>>')(other)
+            
+        __rshift__ = strictly_right_of
+        
+        def not_extend_right_of(self, other):
+            """Boolean expression. Returns true if the range in the column
+            does not extend right of the range in the operand.
+            """
+            return self.expr.op('&<')(other)
+        
+        def not_extend_left_of(self, other):
+            """Boolean expression. Returns true if the range in the column
+            does not extend left of the range in the operand.
+            """
+            return self.expr.op('&>')(other)
+
+        def adjacent_to(self, other):
+            """Boolean expression. Returns true if the range in the column
+            is adjacent to the range in the operand.
+            """
+            return self.expr.op('-|-')(other)
+
+        def __add__(self, other):
+            """Range expression. Returns the union of the two ranges.
+            Will raise an exception if the resulting range is not
+            contigous.
+            """
+            return self.expr.op('+')(other)
+
+class INT4RANGE(RangeOperators, sqltypes.TypeEngine):
     "Represent the Postgresql INT4RANGE type."
     
     __visit_name__ = 'INT4RANGE'
 
 ischema_names['int4range'] = INT4RANGE
 
-class INT8RANGE(sqltypes.TypeEngine):
+class INT8RANGE(RangeOperators, sqltypes.TypeEngine):
     "Represent the Postgresql INT8RANGE type."
     
     __visit_name__ = 'INT8RANGE'
 
 ischema_names['int8range'] = INT8RANGE
 
-class NUMRANGE(sqltypes.TypeEngine):
+class NUMRANGE(RangeOperators, sqltypes.TypeEngine):
     "Represent the Postgresql NUMRANGE type."
     
     __visit_name__ = 'NUMRANGE'
 
 ischema_names['numrange'] = NUMRANGE
 
-class DATERANGE(sqltypes.TypeEngine):
+class DATERANGE(RangeOperators, sqltypes.TypeEngine):
     "Represent the Postgresql DATERANGE type."
     
     __visit_name__ = 'DATERANGE'
 
 ischema_names['daterange'] = DATERANGE
 
-class TSRANGE(sqltypes.TypeEngine):
+class TSRANGE(RangeOperators, sqltypes.TypeEngine):
     "Represent the Postgresql TSRANGE type."
     
     __visit_name__ = 'TSRANGE'
 
 ischema_names['tsrange'] = TSRANGE
 
-class TSTZRANGE(sqltypes.TypeEngine):
+class TSTZRANGE(RangeOperators, sqltypes.TypeEngine):
     "Represent the Postgresql TSTZRANGE type."
     
     __visit_name__ = 'TSTZRANGE'