- if sys.version_info >= (3, 8):
- # TODO: support Python 4+ ;)
- for minor_version in range(sys.version_info[1], 4, -1):
- try:
- return ast.parse(src, filename, feature_version=(3, minor_version))
- except SyntaxError:
- continue
- else:
- for feature_version in (7, 6):
- try:
- return ast3.parse(src, filename, feature_version=feature_version)
- except SyntaxError:
- continue
- if ast27.__name__ == "ast":
- raise SyntaxError(
- "The requested source code has invalid Python 3 syntax.\n"
- "If you are trying to format Python 2 files please reinstall Black"
- " with the 'python2' extra: `python3 -m pip install black[python2]`."
- )
- return ast27.parse(src)
+ # typed_ast is needed because of feature version limitations in the builtin ast
+ if sys.version_info >= (3, 8) and version >= (3,):
+ return ast.parse(src, filename, feature_version=version)
+ elif version >= (3,):
+ if _IS_PYPY:
+ return ast3.parse(src, filename)
+ else:
+ return ast3.parse(src, filename, feature_version=version[1])
+ elif version == (2, 7):
+ return ast27.parse(src)
+ raise AssertionError("INTERNAL ERROR: Tried parsing unsupported Python version!")
+
+
+def parse_ast(src: str) -> Union[ast.AST, ast3.AST, ast27.AST]:
+ # TODO: support Python 4+ ;)
+ versions = [(3, minor) for minor in range(3, sys.version_info[1] + 1)]
+
+ if ast27.__name__ != "ast":
+ versions.append((2, 7))
+
+ first_error = ""
+ for version in sorted(versions, reverse=True):
+ try:
+ return parse_single_version(src, version)
+ except SyntaxError as e:
+ if not first_error:
+ first_error = str(e)
+
+ raise SyntaxError(first_error)