Add _subs_repr to other types; fix minor bugs

python · gvanrossum · Oct 20, 2016 · Oct 10, 2016 · Oct 10, 2016 · Oct 10, 2016
commit 232f80ad41efbbaba9ccb546d85ec58a83beab1a
diff --git a/python2/test_typing.py b/python2/test_typing.py
@@ -521,9 +521,9 @@ def test_init(self):
 
     def test_repr(self):
         self.assertEqual(repr(SimpleMapping),
-                         __name__ + '.' + 'SimpleMapping[~XK, ~XV]')
+                         __name__ + '.' + 'SimpleMapping')
         self.assertEqual(repr(MySimpleMapping),
-                         __name__ + '.' + 'MySimpleMapping[~XK, ~XV]')
+                         __name__ + '.' + 'MySimpleMapping')
 
     def test_chain_repr(self):
         T = TypeVar('T')
@@ -554,7 +554,7 @@ def test_new_repr(self):
         U = TypeVar('U', covariant=True)
         S = TypeVar('S')
 
-        self.assertEqual(repr(List), 'typing.List[~T]')
+        self.assertEqual(repr(List), 'typing.List')
         self.assertEqual(repr(List[T]), 'typing.List[~T]')
         self.assertEqual(repr(List[U]), 'typing.List[+U]')
         self.assertEqual(repr(List[S][T][int]), 'typing.List[int]')
@@ -664,7 +664,7 @@ class C(Generic[T]):
         if not PY32:
             self.assertEqual(C.__qualname__,
                              'GenericTests.test_repr_2.<locals>.C')
-        self.assertEqual(repr(C).split('.')[-1], 'C[~T]')
+        self.assertEqual(repr(C).split('.')[-1], 'C')
         X = C[int]
         self.assertEqual(X.__module__, __name__)
         if not PY32:

diff --git a/python2/typing.py b/python2/typing.py
@@ -276,8 +276,8 @@ def __getitem__(self, parameter):
             if not issubclass(parameter, self.type_var.__constraints__):
                 raise TypeError("%s is not a valid substitution for %s." %
                                 (parameter, self.type_var))
-        if isinstance(parameter, TypeVar):
-            raise TypeError("%s cannot be re-parameterized." % self.type_var)
+        if isinstance(parameter, TypeVar) and parameter is not self.type_var:
+            raise TypeError("%s cannot be re-parameterized." % self)
         return self.__class__(self.name, parameter,
                               self.impl_type, self.type_checker)
 
@@ -398,12 +398,15 @@ def _eval_type(self, globalns, localns):
 
     def _get_type_vars(self, tvars):
         if self.__type__:
-            _get_type_vars(self.__type__, tvars)
+            _get_type_vars([self.__type__], tvars)
 
     def __repr__(self):
+        return self._subs_repr([], [])
+
+    def _subs_repr(self, tvars, args):
         r = super(_ClassVar, self).__repr__()
         if self.__type__ is not None:
-            r += '[{}]'.format(_type_repr(self.__type__))
+            r += '[{}]'.format(_replace_arg(self.__type__, tvars, args))
         return r
 
     def __hash__(self):
@@ -703,9 +706,12 @@ def _get_type_vars(self, tvars):
             _get_type_vars(self.__union_params__, tvars)
 
     def __repr__(self):
+        return self._subs_repr([], [])
+
+    def _subs_repr(self, tvars, args):
         r = super(_Union, self).__repr__()<
10000
/span>
         if self.__union_params__:
-            r += '[%s]' % (', '.join(_type_repr(t)
+            r += '[%s]' % (', '.join(_replace_arg(t, tvars, args)
                                      for t in self.__union_params__))
         return r
 
@@ -805,9 +811,12 @@ def _eval_type(self, globalns, localns):
             return self.__class__(p, _root=True)
 
     def __repr__(self):
+        return self._subs_repr([], [])
+
+    def _subs_repr(self, tvars, args):
         r = super(_Tuple, self).__repr__()
         if self.__tuple_params__ is not None:
-            params = [_type_repr(p) for p in self.__tuple_params__]
+            params = [_replace_arg(p, tvars, args) for p in self.__tuple_params__]
             if self.__tuple_use_ellipsis__:
                 params.append('...')
             if not params:
@@ -898,6 +907,8 @@ def __init__(self, args=None, result=None, _root=False):
     def _get_type_vars(self, tvars):
         if self.__args__ and self.__args__ is not Ellipsis:
             _get_type_vars(self.__args__, tvars)
+        if self.__result__:
+            _get_type_vars([self.__result__], tvars)
 
     def _eval_type(self, globalns, localns):
         if self.__args__ is None and self.__result__ is None:
@@ -913,14 +924,17 @@ def _eval_type(self, globalns, localns):
             return self.__class__(args=args, result=result, _root=True)
 
     def __repr__(self):
+        return self._subs_repr([], [])
+
+    def _subs_repr(self, tvars, args):
         r = super(_Callable, self).__repr__()
         if self.__args__ is not None or self.__result__ is not None:
             if self.__args__ is Ellipsis:
                 args_r = '...'
             else:
-                args_r = '[%s]' % ', '.join(_type_repr(t)
+                args_r = '[%s]' % ', '.join(_replace_arg(t, tvars, args)
                                             for t in self.__args__)
-            r += '[%s, %s]' % (args_r, _type_repr(self.__result__))
+            r += '[%s, %s]' % (args_r, _replace_arg(self.__result__, tvars, args))
         return r
 
     def __getitem__(self, parameters):
@@ -985,6 +999,16 @@ def _geqv(a, b):
     return _gorg(a) is _gorg(b)
 
 
+def _replace_arg(arg, tvars, args):
+    if hasattr(arg, '_subs_repr'):
+        return arg._subs_repr(tvars, args)
+    if isinstance(arg, TypeVar):
+       for i, tvar in enumerate(tvars):
+           if arg.__name__ == tvar.__name__:
+               return args[i]
+    return _type_repr(arg)
+
+
 def _next_in_mro(cls):
     """Helper for Generic.__new__.
 
@@ -1115,29 +1139,29 @@ def _get_type_vars(self, tvars):
             _get_type_vars(self.__parameters__, tvars)
 
     def __repr__(self):
-        return super(GenericMeta, self).__repr__() + self._arg_repr()
-
-    def _arg_repr(self):
-        par_repr = '[%s]' % (', '.join(map(_type_repr, self.__parameters__)))
-        if self.__origin__ in [Generic, _Protocol]:
-            return par_repr
         if self.__origin__ is None:
-            if not self.__parameters__:
-                return ''
-            return par_repr
+            return super(GenericMeta, self).__repr__()
+        return self._subs_repr([], [])
 
-        current = self
+    def _subs_repr(self, tvars, args):
+        assert len(tvars) == len(args)
+        # Construct the chain of __origin__'s.
+        current = self.__origin__
         orig_chain = []
         while current.__origin__ is not None:
             orig_chain.append(current)
             current = current.__origin__
-        r = '[%s]' % (', '.join(map(_type_repr, orig_chain[-1].__origin__.__parameters__)))
-        for tp in reversed(orig_chain):
-            for i in range(len(tp.__args__)):  # replace free parameters with args
-                par = stdlib_re.escape(_type_repr(tp.__origin__.__parameters__[i]))
-                r = stdlib_re.sub(par + '(?=[,\]])', '{%r}' % i, r)
-            r = r.format(*map(_type_repr, tp.__args__))
-        return r
+        # Replace type variables in __args__ if asked ...
+        str_args = []
+        for arg in self.__args__:
+            str_args.append(_replace_arg(arg, tvars, args))
+        # ... then continue replacing down the origin chain.
+        for cls in orig_chain:
+            new_str_args = []
+            for i, arg in enumerate(cls.__args__):
+                new_str_args.append(_replace_arg(arg, cls.__parameters__, str_args))
+            str_args = new_str_args
+        return super(GenericMeta, self).__repr__() + '[%s]' % ', '.join(str_args)
 
     def __eq__(self, other):
         if not isinstance(other, GenericMeta):
@@ -1170,11 +1194,11 @@ def __getitem__(self, params):
                 raise TypeError(
                     "Parameters to Generic[...] must all be unique")
             tvars = params
-            args = None
+            args = params
         elif self is _Protocol:
             # _Protocol is internal, don't check anything.
             tvars = params
-            args = None
+            args = params
         elif self.__origin__ in (Generic, _Protocol):
             # Can't subscript Generic[...] or _Protocol[...].
             raise TypeError("Cannot subscript already-subscripted %s" %

diff --git a/src/test_typing.py b/src/test_typing.py
@@ -548,9 +548,9 @@ def test_init(self):
 
     def test_repr(self):
         self.assertEqual(repr(SimpleMapping),
-                         __name__ + '.' + 'SimpleMapping[~XK, ~XV]')
+                         __name__ + '.' + 'SimpleMapping')
         self.assertEqual(repr(MySimpleMapping),
-                         __name__ + '.' + 'MySimpleMapping[~XK, ~XV]')
+                         __name__ + '.' + 'MySimpleMapping')
 
     def test_chain_repr(self):
         T = TypeVar('T')
@@ -581,7 +581,7 @@ def test_new_repr(self):
         U = TypeVar('U', covariant=True)
         S = TypeVar('S')
 
-        self.assertEqual(repr(List), 'typing.List[~T]')
+        self.assertEqual(repr(List), 'typing.List')
         self.assertEqual(repr(List[T]), 'typing.List[~T]')
         self.assertEqual(repr(List[U]), 'typing.List[+U]')
         self.assertEqual(repr(List[S][T][int]), 'typing.List[int]')
@@ -691,7 +691,7 @@ class C(Generic[T]):
         if not PY32:
             self.assertEqual(C.__qualname__,
                              'GenericTests.test_repr_2.<locals>.C')
-        self.assertEqual(repr(C).split('.')[-1], 'C[~T]')
+        self.assertEqual(repr(C).split('.')[-1], 'C')
         X = C[int]
         self.assertEqual(X.__module__, __name__)
         if not PY32:

diff --git a/src/typing.py b/src/typing.py
@@ -292,8 +292,8 @@ def __getitem__(self, parameter):
             if not issubclass(parameter, self.type_var.__constraints__):
                 raise TypeError("%s is not a valid substitution for %s." %
                                 (parameter, self.type_var))
-        if isinstance(parameter, TypeVar):
-            raise TypeError("%s cannot be re-parameterized." % self.type_var)
+        if isinstance(parameter, TypeVar) and parameter is not self.type_var:
+            raise TypeError("%s cannot be re-parameterized." % self)
         return self.__class__(self.name, parameter,
                               self.impl_type, self.type_checker)
 
@@ -622,9 +622,12 @@ def _get_type_vars(self, tvars):
             _get_type_vars(self.__union_params__, tvars)
 
     def __repr__(self):
+        return self._subs_repr([], [])
+
+    def _subs_repr(self, tvars, args):
         r = super().__repr__()
         if self.__union_params__:
-            r += '[%s]' % (', '.join(_type_repr(t)
+            r += '[%s]' % (', '.join(_replace_arg(t, tvars, args)
                                      for t in self.__union_params__))
         return r
 
@@ -706,9 +709,12 @@ def _eval_type(self, globalns, localns):
             return self.__class__(p, _root=True)
 
     def __repr__(self):
+        return self._subs_repr([], [])
+
+    def _subs_repr(self, tvars, args):
         r = super().__repr__()
         if self.__tuple_params__ is not None:
-            params = [_type_repr(p) for p in self.__tuple_params__]
+            params = [_replace_arg(p, tvars, args) for p in self.__tuple_params__]
             if self.__tuple_use_ellipsis__:
                 params.append('...')
             if not params:
@@ -791,6 +797,8 @@ def __init__(self, args=None, result=None, _root=False):
     def _get_type_vars(self, tvars):
         if self.__args__ and self.__args__ is not Ellipsis:
             _get_type_vars(self.__args__, tvars)
+        if self.__result__:
+            _get_type_vars([self.__result__], tvars)
 
     def _eval_type(self, globalns, localns):
         if self.__args__ is None and self.__result__ is None:
@@ -806,14 +814,17 @@ def _eval_type(self, globalns, localns):
             return self.__class__(args, result, _root=True)
 
     def __repr__(self):
+        return self._subs_repr([], [])
+
+    def _subs_repr(self, tvars, args):
         r = super().__repr__()
         if self.__args__ is not None or self.__result__ is not None:
             if self.__args__ is Ellipsis:
                 args_r = '...'
             else:
-                args_r = '[%s]' % ', '.join(_type_repr(t)
+                args_r = '[%s]' % ', '.join(_replace_arg(t, tvars, args)
                                             for t in self.__args__)
-            r += '[%s, %s]' % (args_r, _type_repr(self.__result__))
+            r += '[%s, %s]' % (args_r, _replace_arg(self.__result__, tvars, args))
         return r
 
     def __getitem__(self, parameters):
@@ -878,6 +889,16 @@ def _geqv(a, b):
     return _gorg(a) is _gorg(b)
 
 
+def _replace_arg(arg, tvars, args):
+    if hasattr(arg, '_subs_repr'):
+        return arg._subs_repr(tvars, args)
+    if isinstance(arg, TypeVar):
+       for i, tvar in enumerate(tvars):
+           if arg.__name__ == tvar.__name__:
+               return args[i]
+    return _type_repr(arg)
+
+
 def _next_in_mro(cls):
     """Helper for Generic.__new__.
 
@@ -1005,6 +1026,11 @@ def _get_type_vars(self, tvars):
         if self.__origin__ and self.__parameters__:
             _get_type_vars(self.__parameters__, tvars)
 
+    def __repr__(self):
+        if self.__origin__ is None:
+            return super().__repr__()
+        return self._subs_repr([], [])
+
     def _subs_repr(self, tvars, args):
         assert len(tvars) == len(args)
         # Construct the chain of __origin__'s.
@@ -1025,14 +1051,6 @@ def _subs_repr(self, tvars, args):
             str_args = new_str_args
         return super().__repr__() + '[%s]' % ', '.join(str_args)
 
-    def __repr__(self):
-        r = super().__repr__()
-        if self.__origin__ is None:
-            return r
-        if self.__origin__ in [Generic, _Protocol]:
-            return r + '[%s]' % ', '.join(map(_type_repr, self.__parameters__))
-        return self._subs_repr([], [])  # Not necessary to replace anything
-
     def __eq__(self, other):
         if not isinstance(other, GenericMeta):
             return NotImplemented
@@ -1064,11 +1082,11 @@ def __getitem__(self, params):
                 raise TypeError(
                     "Parameters to Generic[...] must all be unique")
             tvars = params
-            args = None
+            args = params
         elif self is _Protocol:
             # _Protocol is internal, don't check anything.
             tvars = params
-            args = None
+            args = params
         elif self.__origin__ in (Generic, _Protocol):
             # Can't subscript Generic[...] or _Protocol[...].
             raise TypeError("Cannot subscript already-subscripted %s" %
@@ -1102,16 +1120,6 @@ def __instancecheck__(self, instance):
         return issubclass(instance.__class__, self)
 
 
-def _replace_arg(arg, tvars, args):
-    if isinstance(arg, GenericMeta):
-        return arg._subs_repr(tvars, args)
-    if isinstance(arg, TypeVar):
-       for i, tvar in enumerate(tvars):
-           if arg.__name__ == tvar.__name__:
-               return args[i]
-    return _type_repr(arg)
-
-
 # Prevent checks for Generic to crash when defining Generic.
 Generic = None
 
@@ -1188,12 +1196,15 @@ def _eval_type(self, globalns, localns):
 
     def _get_type_vars(self, tvars):
         if self.__type__:
-            _get_type_vars(self.__type__, tvars)
+            _get_type_vars([self.__type__], tvars)
 
     def __repr__(self):
+        return self._subs_repr([], [])
+
+    def _subs_repr(self, tvars, args):
         r = super().__repr__()
         if self.__type__ is not None:
-            r += '[{}]'.format(_type_repr(self.__type__))
+            r += '[{}]'.format(_replace_arg(self.__type__, tvars, args))
         return r
 
     def __hash__(self):