Merge with mypy master

Author: quartox

.travis.yml

@@ -15,6 +15,7 @@ python:
 
 install:
   - pip install -r test-requirements.txt
+  - python2 -m pip install --user typing
   - python setup.py install
 
 script:

LICENSE

@@ -27,8 +27,7 @@ DEALINGS IN THE SOFTWARE.
 = = = = =
 
 Portions of mypy are licensed under different licenses.  The files
-under stdlib-samples and lib-typing are licensed under the PSF 2
-License, reproduced below.
+under stdlib-samples are licensed under the PSF 2 License, reproduced below.
 
 = = = = =
 

ROADMAP.md

@@ -0,0 +1,96 @@
+# Mypy Roadmap
+
+The goal of the roadmap is to document areas the mypy core team is
+planning to work on in the future or is currently working on. PRs
+targeting these areas are very welcome, but please check first with a
+core team member that nobody else is working on the same thing.
+
+**Note:** This doesn’t include everything that the core team will work
+on, and everything is subject to change. Near-term plans are likely
+more accurate.
+
+## April-June 2017
+
+- Add more comprehensive testing for `--incremental` and `--quick`
+  modes to improve reliability. At least write more unit tests with
+  focus on areas that have previously had bugs.
+  ([issue](https://github.com/python/mypy/issues/3455))
+
+- Speed up `--quick` mode to better support million+ line codebases
+  through some of these:
+
+  - Make it possible to use remote caching for incremental cache
+    files. This would speed up a cold run with no local cache data.
+    We need to update incremental cache to use hashes to determine
+    whether files have changes to allow
+    [sharing cache data](https://github.com/python/mypy/issues/3403).
+
+  - See if we can speed up deserialization of incremental cache
+    files. Initial experiments aren’t very promising though so there
+    might not be any easy wins left.
+    ([issue](https://github.com/python/mypy/issues/3456))
+
+- Improve support for complex signatures such as `open(fn, 'rb')` and
+  specific complex decorators such as `contextlib.contextmanager`
+  through type checker plugins/hooks.
+  ([issue](https://github.com/python/mypy/issues/1240))
+
+- Document basic properties of all type operations used within mypy,
+  including compatibility, proper subtyping, joins and meets.
+  ([issue](https://github.com/python/mypy/issues/3454))
+
+- Make TypedDict an officially supported mypy feature. This makes it
+  possible to give precise types for dictionaries that represent JSON
+  objects, such as `{"path": "/dir/fnam.ext", "size": 1234}`.
+  ([issue](https://github.com/python/mypy/issues/3453))
+
+- Make error messages more useful and informative.
+  ([issue](https://github.com/python/mypy/labels/topic-usability))
+
+- Resolve [#2008](https://github.com/python/mypy/issues/2008) (we are
+  converging on approach 4).
+
+## July-December 2017
+
+- Invest some effort into systematically filling in missing
+  annotations and stubs in typeshed, with focus on features heavily
+  used at Dropbox. Better support for ORMs will be a separate
+  project.
+
+- Improve opt-in warnings about `Any` types to make it easier to keep
+  code free from unwanted `Any` types. For example, warn about using
+  `list` (instead of `List[x]`) and calling `open` if we can’t infer a
+  precise return type, or using types imported from ignored modules
+  (they are implicitly `Any`).
+
+- Add support for protocols and structural subtyping (PEP 544).
+
+- Switch completely to pytest and remove the custom testing framework.
+  ([issue](https://github.com/python/mypy/issues/1673))
+
+- Make it possible to run mypy as a daemon to avoid reprocessing the
+  entire program on each run. This will improve performance
+  significantly. Even when using the incremental mode, processing a
+  large number of files is not cheap.
+
+- Refactor and simplify specific tricky parts of mypy internals, such
+  as the [conditional type binder](https://github.com/python/mypy/issues/3457),
+  [symbol tables](https://github.com/python/mypy/issues/3458) or
+  the various [semantic analysis passes](https://github.com/python/mypy/issues/3459).
+
+- Implement a general type system plugin architecture. It should be
+  able to support some typical ORM features at least, such as
+  metaclasses that add methods with automatically inferred signatures
+  and complex descriptors such as those used by Django models.
+  ([issue](https://github.com/python/mypy/issues/1240))
+
+- Add support for statically typed
+  [protobufs](https://developers.google.com/protocol-buffers/).
+
+- Provide much faster, reliable interactive feedback through
+  fine-grained incremental type checking, built on top the daemon
+  mode.
+
+- Start work on editor plugins and support for selected IDE features.
+
+- Turn on `--strict-optional` by default.

docs/source/cheat_sheet.rst

@@ -149,6 +149,18 @@ When you're puzzled or when things are complicated
    reveal_type(c)  # -> error: Revealed type is 'builtins.list[builtins.str]'
    print(c)  # -> [4] the object is not cast
 
+   # if you want dynamic attributes on your class, have it override __setattr__ or __getattr__
+   # in a stub or in your source code.
+   # __setattr__ allows for dynamic assignment to names
+   # __getattr__ allows for dynamic access to names
+   class A:
+       # this will allow assignment to any A.x, if x is the same type as `value`
+       def __setattr__(self, name, value):
+           # type: (str, int) -> None
+           ...
+   a.foo = 42  # works
+   a.bar = 'Ex-parrot'  # fails type checking
+
    # TODO: explain "Need type annotation for variable" when
    # initializing with None or an empty container
 

docs/source/cheat_sheet_py3.rst

@@ -142,6 +142,19 @@ When you're puzzled or when things are complicated
    reveal_type(c)  # -> error: Revealed type is 'builtins.list[builtins.str]'
    print(c)  # -> [4] the object is not cast
 
+   # if you want dynamic attributes on your class, have it override __setattr__ or __getattr__
+   # in a stub or in your source code.
+   # __setattr__ allows for dynamic assignment to names
+   # __getattr__ allows for dynamic access to names
+   class A:
+       # this will allow assignment to any A.x, if x is the same type as `value`
+       def __setattr__(self, name: str, value: int) -> None: ...
+       # this will allow access to any A.x, if x is compatible with the return type
+       def __getattr__(self, name: str) -> int: ...
+   a.foo = 42  # works
+   a.bar = 'Ex-parrot'  # fails type checking
+
+
    # TODO: explain "Need type annotation for variable" when
    # initializing with None or an empty container
 

docs/source/common_issues.rst

@@ -180,7 +180,7 @@ not support ``sort()``) as a list and sort it in-place:
         # Type of x is List[int] here.
         x.sort()  # Okay!
 
-.. _invariance-vs-covariance:
+.. _variance:
 
 Invariance vs covariance
 ------------------------

docs/source/config_file.rst

@@ -178,6 +178,8 @@ overridden by the pattern sections matching the module name.
 - ``strict_boolean`` (Boolean, default False) makes using non-boolean
   expressions in conditions an error.
 
+- ``no_implicit_optional`` (Boolean, default false) changes the treatment of
+  arguments with a default value of None by not implicitly making their type Optional
 
 Example
 *******

docs/source/revision_history.rst

@@ -31,7 +31,7 @@ List of major changes:
 
     * Add :ref:`variance-of-generics`.
 
-    * Add :ref:`invariance-vs-covariance`.
+    * Add :ref:`variance`.
 
     * Updates to :ref:`python-36`.
 

extensions/setup.py

@@ -4,7 +4,7 @@
 
 from distutils.core import setup
 
-version = '0.2.0'
+version = '0.3.0-dev'
 description = 'Experimental type system extensions for programs checked with the mypy typechecker.'
 long_description = '''
 Mypy Extensions