From ba67f7dbc5eb7a1ed2a3e1b56df72a837130f7bb Mon Sep 17 00:00:00 2001
From: Mike Bayer <mike_mp@zzzcomputing.com>
Date: Thu, 18 Oct 2012 12:29:41 -0400
Subject: [PATCH]   - [bug] TypeDecorator now includes a generic repr()    
 that works in terms of the "impl" type by default.     This is a behavioral
 change for those TypeDecorator     classes that specify a custom __init__
 method; those     types will need to re-define __repr__() if they need    
 __repr__() to provide a faithful constructor representation.    
 [ticket:2594]

---
 CHANGES                            | 8 ++++++++
 lib/sqlalchemy/types.py            | 3 +++
 lib/sqlalchemy/util/langhelpers.py | 6 ++++--
 test/sql/test_types.py             | 6 ++++++
 4 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/CHANGES b/CHANGES
index 97f5061c0f..084ab4eadd 100644
--- a/CHANGES
+++ b/CHANGES
@@ -716,6 +716,14 @@ underneath "0.7.xx".
     but not ForeignKeyConstraint or CheckConstraint.
     [ticket:2410]
 
+  - [bug] TypeDecorator now includes a generic repr()
+    that works in terms of the "impl" type by default.
+    This is a behavioral change for those TypeDecorator
+    classes that specify a custom __init__ method; those
+    types will need to re-define __repr__() if they need
+    __repr__() to provide a faithful constructor representation.
+    [ticket:2594]
+
   - [bug] column.label(None) now produces an
     anonymous label, instead of returning the
     column object itself, consistent with the behavior
diff --git a/lib/sqlalchemy/types.py b/lib/sqlalchemy/types.py
index ebcffca6e2..e31cecfe22 100644
--- a/lib/sqlalchemy/types.py
+++ b/lib/sqlalchemy/types.py
@@ -817,6 +817,9 @@ class TypeDecorator(TypeEngine):
         """
         return self.impl.compare_values(x, y)
 
+    def __repr__(self):
+        return util.generic_repr(self, to_inspect=self.impl)
+
 
 class Variant(TypeDecorator):
     """A wrapping type that selects among a variety of
diff --git a/lib/sqlalchemy/util/langhelpers.py b/lib/sqlalchemy/util/langhelpers.py
index 9761aeae9f..55b78090a5 100644
--- a/lib/sqlalchemy/util/langhelpers.py
+++ b/lib/sqlalchemy/util/langhelpers.py
@@ -281,14 +281,16 @@ def unbound_method_to_callable(func_or_cls):
     else:
         return func_or_cls
 
-def generic_repr(obj, additional_kw=()):
+def generic_repr(obj, additional_kw=(), to_inspect=None):
     """Produce a __repr__() based on direct association of the __init__()
     specification vs. same-named attributes present.
 
     """
+    if to_inspect is None:
+        to_inspect = obj
     def genargs():
         try:
-            (args, vargs, vkw, defaults) = inspect.getargspec(obj.__init__)
+            (args, vargs, vkw, defaults) = inspect.getargspec(to_inspect.__init__)
         except TypeError:
             return
 
diff --git a/test/sql/test_types.py b/test/sql/test_types.py
index 1d096d7c41..98bc516247 100644
--- a/test/sql/test_types.py
+++ b/test/sql/test_types.py
@@ -336,6 +336,12 @@ class UserDefinedTest(fixtures.TablesTest, AssertsCompiledSQL):
                 Float().dialect_impl(pg).__class__
         )
 
+    def test_type_decorator_repr(self):
+        class MyType(TypeDecorator):
+            impl = VARCHAR
+
+        eq_(repr(MyType(45)), "MyType(length=45)")
+
     def test_user_defined_typedec_impl_bind(self):
         class TypeOne(types.TypeEngine):
             def bind_processor(self, dialect):
-- 
2.47.3