mirror of
https://github.com/Instagram/LibCST.git
synced 2025-12-23 10:35:53 +00:00
82 lines
2.8 KiB
Python
82 lines
2.8 KiB
Python
# Copyright (c) Facebook, Inc. and its affiliates.
|
|
#
|
|
# This source code is licensed under the MIT license found in the
|
|
# LICENSE file in the root directory of this source tree.
|
|
|
|
# pyre-strict
|
|
"""
|
|
Parser entrypoints define the way users of our API are allowed to interact with the
|
|
parser. A parser entrypoint should take the source code and some configuration
|
|
information
|
|
"""
|
|
|
|
from typing import TypeVar, Union
|
|
|
|
import libcst.nodes as cst
|
|
from libcst.parser._detect_config import detect_config
|
|
from libcst.parser._grammar import get_grammar, validate_grammar
|
|
from libcst.parser._python_parser import PythonCSTParser
|
|
from libcst.parser._types.config import PartialParserConfig
|
|
|
|
|
|
_CSTNodeT = TypeVar("_CSTNodeT", bound=cst.CSTNode)
|
|
_DEFAULT_PARTIAL_PARSER_CONFIG: PartialParserConfig = PartialParserConfig()
|
|
|
|
|
|
def _parse(
|
|
entrypoint: str,
|
|
source: Union[str, bytes],
|
|
config: PartialParserConfig,
|
|
*,
|
|
detect_trailing_newline: bool,
|
|
) -> cst.CSTNode:
|
|
detection_result = detect_config(
|
|
source, partial=config, detect_trailing_newline=detect_trailing_newline
|
|
)
|
|
validate_grammar()
|
|
grammar = get_grammar()
|
|
|
|
parser = PythonCSTParser(
|
|
tokens=detection_result.tokens,
|
|
config=detection_result.config,
|
|
pgen_grammar=grammar,
|
|
start_nonterminal=entrypoint,
|
|
)
|
|
# The parser has an Any return type, we can at least refine it to CSTNode here.
|
|
result = parser.parse()
|
|
assert isinstance(result, cst.CSTNode)
|
|
return result
|
|
|
|
|
|
def parse_module(
|
|
source: Union[str, bytes], # the only entrypoint that accepts bytes
|
|
config: PartialParserConfig = _DEFAULT_PARTIAL_PARSER_CONFIG,
|
|
) -> cst.Module:
|
|
result = _parse("file_input", source, config, detect_trailing_newline=True)
|
|
assert isinstance(result, cst.Module)
|
|
return result
|
|
|
|
|
|
def parse_statement(
|
|
source: str, config: PartialParserConfig = _DEFAULT_PARTIAL_PARSER_CONFIG
|
|
) -> Union[cst.SimpleStatementLine, cst.BaseCompoundStatement]:
|
|
"""
|
|
Accepts a statement followed by a trailing newline. If a trailing newline is not
|
|
provided, one will be added.
|
|
|
|
Leading comments and trailing comments (on the same line) are accepted, but
|
|
whitespace (or anything else) after the statement's trailing newline is not valid
|
|
(there's nowhere to store it).
|
|
"""
|
|
# use detect_trailing_newline to insert a newline
|
|
result = _parse("stmt_input", source, config, detect_trailing_newline=True)
|
|
assert isinstance(result, (cst.SimpleStatementLine, cst.BaseCompoundStatement))
|
|
return result
|
|
|
|
|
|
def parse_expression(
|
|
source: str, config: PartialParserConfig = _DEFAULT_PARTIAL_PARSER_CONFIG
|
|
) -> cst.BaseExpression:
|
|
result = _parse("expression_input", source, config, detect_trailing_newline=False)
|
|
assert isinstance(result, cst.BaseExpression)
|
|
return result
|