Remove old parser (#2977)

It's no longer needed.

Author: ddfisher

README.md

@@ -116,8 +116,9 @@ this:
 
     $ python3 -m pip install -U mypy
 
-Except on Windows, it's best to always use the `--fast-parser`
-option to mypy; this requires installing `typed-ast`:
+This should automatically installed the appropriate version of
+mypy's parser, typed-ast.  If for some reason it does not, you
+can install it manually:
 
     $ python3 -m pip install -U typed-ast
 

docs/source/command_line.rst

@@ -15,7 +15,7 @@ flag (or its long form ``--help``)::
               [--check-untyped-defs] [--disallow-subclassing-any]
               [--warn-incomplete-stub] [--warn-redundant-casts]
               [--warn-no-return] [--warn-unused-ignores] [--show-error-context]
-              [--fast-parser] [-i] [--cache-dir DIR] [--strict-optional]
+              [-i] [--cache-dir DIR] [--strict-optional]
               [--strict-optional-whitelist [GLOB [GLOB ...]]] [--strict]
               [--junit-xml JUNIT_XML] [--pdb] [--show-traceback] [--stats]
               [--inferstats] [--custom-typing MODULE]
@@ -303,10 +303,6 @@ Here are some more useful flags:
   to speed up type checking. Incremental mode can help when most parts
   of your program haven't changed since the previous mypy run.
 
-- ``--fast-parser`` enables an experimental parser implemented in C that
-  is faster than the default parser and supports multi-line comment
-  function annotations (see :ref:`multi_line_annotation` for the details).
-
 - ``--python-version X.Y`` will make mypy typecheck your code as if it were
   run under Python version X.Y. Without this option, mypy will default to using
   whatever version of Python is running mypy. Note that the ``-2`` and

docs/source/config_file.rst

@@ -93,9 +93,6 @@ The following global flags may only be set in the global section
 - ``dump_inference_stats`` (Boolean, default False) dumps stats about
   type inference.
 
-- ``fast_parser`` (Boolean, default False) enables the experimental
-  fast parser.
-
 - ``incremental`` (Boolean, default False) enables the experimental
   module cache.
 

docs/source/kinds_of_types.rst

@@ -691,12 +691,6 @@ Mypy supports it already:
 
     p = Point(x=1, y='x')  # Argument has incompatible type "str"; expected "int"
 
-.. note::
-
-   The Python 3.6 syntax requires the ``--fast-parser`` flag. You must also have the
-   `typed_ast <https://pypi.python.org/pypi/typed-ast>`_ package
-   installed and have at least version 0.6.1.  Use ``pip3 install -U typed_ast``.
-
 .. _type-of-class:
 
 The type of class objects
@@ -872,15 +866,6 @@ annotated the first example as the following:
 Typing async/await
 ******************
 
-.. note::
-
-   Currently, you must pass in the ``--fast-parser`` flag if you want to run
-   mypy against code containing the ``async/await`` keywords. The fast parser
-   will be enabled by default in a future version of mypy.
-
-   Note that mypy will understand coroutines created using the ``@asyncio.coroutine``
-   decorator both with and without the fast parser enabled.
-
 Mypy supports the ability to type coroutines that use the ``async/await``
 syntax introduced in Python 3.5. For more information regarding coroutines and
 this new syntax, see `PEP 492 <https://www.python.org/dev/peps/pep-0492/>`_.

docs/source/python2.rst

@@ -66,12 +66,6 @@ overly long type comments and it's often tricky to see which argument
 type corresponds to which argument. The alternative, multi-line
 annotation syntax makes long annotations easier to read and write.
 
-.. note::
-
-    Multi-line comment annotations currently only work when using the
-    ``--fast-parser`` command line option.  This is not enabled by
-    default because the option isn’t supported on Windows yet.
-
 Here is an example (from PEP 484):
 
 .. code-block:: python

mypy/checker.py

@@ -1836,9 +1836,8 @@ def visit_assert_stmt(self, s: AssertStmt) -> None:
         if s.msg is not None:
             self.expr_checker.accept(s.msg)
 
-        if self.options.fast_parser:
-            if isinstance(s.expr, TupleExpr) and len(s.expr.items) > 0:
-                self.warn(messages.MALFORMED_ASSERT, s)
+        if isinstance(s.expr, TupleExpr) and len(s.expr.items) > 0:
+            self.warn(messages.MALFORMED_ASSERT, s)
 
         # If this is asserting some isinstance check, bind that type in the following code
         true_map, _ = self.find_isinstance_check(s.expr)

mypy/exprtotype.py

@@ -5,7 +5,7 @@
     ListExpr, StrExpr, BytesExpr, UnicodeExpr, EllipsisExpr,
     get_member_expr_fullname
 )
-from mypy.parsetype import parse_str_as_type, TypeParseError
+from mypy.fastparse import parse_type_comment
 from mypy.types import Type, UnboundType, TypeList, EllipsisType
 
 
@@ -49,8 +49,8 @@ def expr_to_unanalyzed_type(expr: Expression) -> Type:
     elif isinstance(expr, (StrExpr, BytesExpr, UnicodeExpr)):
         # Parse string literal type.
         try:
-            result = parse_str_as_type(expr.value, expr.line)
-        except TypeParseError:
+            result = parse_type_comment(expr.value, expr.line, None)
+        except SyntaxError:
             raise TypeTranslationError()
         return result
     elif isinstance(expr, EllipsisExpr):

mypy/fastparse.py

@@ -95,8 +95,11 @@ def parse_type_comment(type_comment: str, line: int, errors: Errors) -> Optional
     try:
         typ = ast3.parse(type_comment, '<type_comment>', 'eval')
     except SyntaxError as e:
-        errors.report(line, e.offset, TYPE_COMMENT_SYNTAX_ERROR)
-        return None
+        if errors is not None:
+            errors.report(line, e.offset, TYPE_COMMENT_SYNTAX_ERROR)
+            return None
+        else:
+            raise
     else:
         assert isinstance(typ, ast3.Expression)
         return TypeConverter(errors, line=line).visit(typ.body)