def _pick_compatible_python_version(version: Optional[str] = None) -> PythonVersionInfo:
max_version = parse_version_string(version)
for v in KNOWN_PYTHON_VERSION_STRINGS[::-1]:
tmp = parse_version_string(v)
if tmp <= max_version:
return tmp
raise ValueError(
f"No version found older than {version} ({max_version}) while "
+ f"running on {sys.version_info}"
)
def __post_init__(self) -> None:
raw_python_version = self.python_version
if isinstance(raw_python_version, AutoConfig):
# If unspecified, we'll try to pick the same as the running
# interpreter. There will always be at least one entry.
parsed_python_version = _pick_compatible_python_version()
else:
# If the caller specified a version, we require that to be a known
# version (because we don't want to encourage doing duplicate work
# when there weren't syntax changes).
# `parse_version_string` will raise a ValueError if the version is
# invalid.
parsed_python_version = parse_version_string(raw_python_version)
if not any(
parsed_python_version == parse_version_string(v)
for v in KNOWN_PYTHON_VERSION_STRINGS
):
comma_versions = ", ".join(KNOWN_PYTHON_VERSION_STRINGS)
raise ValueError(
"LibCST can only parse code using one of the following versions of "
+ f"Python's grammar: {comma_versions}. More versions may be "
+ "supported by future releases."
)
# We use object.__setattr__ because the dataclass is frozen. See:
# https://docs.python.org/3/library/dataclasses.html#frozen-instances
# This should be safe behavior inside of `__post_init__`.
object.__setattr__(self, "parsed_python_version", parsed_python_version)
encoding = self.encoding
if not isinstance(encoding, AutoConfig):
try:
codecs.lookup(encoding)
except LookupError:
raise ValueError(f"{repr(encoding)} is not a supported encoding")
newline = self.default_newline
if (
not isinstance(newline, AutoConfig)
and NEWLINE_RE.fullmatch(newline) is None
):
raise ValueError(
f"Got an invalid value for default_newline: {repr(newline)}"
)
indent = self.default_indent
if not isinstance(indent, AutoConfig) and _INDENT_RE.fullmatch(indent) is None:
raise ValueError(f"Got an invalid value for default_indent: {repr(indent)}")
def __post_init__(self) -> None:
raw_python_version = self.python_version
# `parse_version_string` will raise a ValueError if the version is invalid.
#
# We use object.__setattr__ because the dataclass is frozen. See:
# https://docs.python.org/3/library/dataclasses.html#frozen-instances
# This should be safe behavior inside of `__post_init__`.
parsed_python_version = parse_version_string(
None if isinstance(raw_python_version, AutoConfig) else raw_python_version
)
# Once we add support for more versions of Python, we can change this to detect
# the supported version range.
if not any(
parsed_python_version == parse_version_string(v)
for v in KNOWN_PYTHON_VERSION_STRINGS
):
comma_versions = ", ".join(KNOWN_PYTHON_VERSION_STRINGS)
raise ValueError(
"LibCST can only parse code using one of the following versions of "
+ f"Python's grammar: {comma_versions}. More versions may be "
+ "supported by future releases."
)
object.__setattr__(self, "parsed_python_version", parsed_python_version)
encoding = self.encoding
if not isinstance(encoding, AutoConfig):
try:
codecs.lookup(encoding)
except LookupError:
raise ValueError(f"{repr(encoding)} is not a supported encoding")
newline = self.default_newline
if (
not isinstance(newline, AutoConfig)
and NEWLINE_RE.fullmatch(newline) is None
):
raise ValueError(
f"Got an invalid value for default_newline: {repr(newline)}"
)
indent = self.default_indent
if not isinstance(indent, AutoConfig) and _INDENT_RE.fullmatch(indent) is None:
raise ValueError(f"Got an invalid value for default_indent: {repr(indent)}")
def _get_version_comparison(version: str) -> Tuple[str, PythonVersionInfo]:
if version[:2] in (">=", "<=", "==", "!="):
return (version[:2], parse_version_string(version[2:].strip()))
if version[:1] in (">", "<"):
return (version[:1], parse_version_string(version[1:].strip()))
raise Exception(f"Invalid version comparison specifier '{version}'")
def __init__(self, bnf_grammar: str) -> None:
self._bnf_grammar: str = bnf_grammar
self.generator = tokenize(bnf_grammar, version_info=parse_version_string("3.6"))
self._gettoken() # Initialize lookahead
def _get_token_list(string, version=None):
# Load the current version.
version_info = parse_version_string(version)
return list(tokenize(string, version_info))
def test_tokenize_start_pos(self, code, positions):
tokens = list(tokenize(code, version_info=parse_version_string("3.6")))
assert positions == [p.start_pos for p in tokens]
