LibCST/libcst/_parser/_conversions/params.py
Jennifer Taylor 3fb60b9706 Make parser package private
Now that this is imported from the top level, make it private.
2019-07-26 12:48:22 -07:00

214 lines
8.1 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.
from typing import Any, List, Optional, Sequence, Union
from libcst._maybe_sentinel import MaybeSentinel
from libcst._nodes._expression import Annotation, Name, Param, Parameters, ParamStar
from libcst._nodes._op import AssignEqual, Comma
from libcst._parser._custom_itertools import grouper
from libcst._parser._production_decorator import with_production
from libcst._parser._types.config import ParserConfig
from libcst._parser._types.partials import ParamStarPartial
from libcst._parser._whitespace_parser import parse_parenthesizable_whitespace
@with_production( # noqa: C901: too complex
"typedargslist",
(
"(tfpdef_assign (',' tfpdef_assign)* "
+ "[',' [tfpdef_star (',' tfpdef_assign)* [',' [tfpdef_starstar [',']]] | tfpdef_starstar [',']]]"
+ "| tfpdef_star (',' tfpdef_assign)* [',' [tfpdef_starstar [',']]] | tfpdef_starstar [','])"
),
)
@with_production(
"varargslist",
(
"(vfpdef_assign (',' vfpdef_assign)* "
+ "[',' [vfpdef_star (',' vfpdef_assign)* [',' [vfpdef_starstar [',']]] | vfpdef_starstar [',']]]"
+ "| vfpdef_star (',' vfpdef_assign)* [',' [vfpdef_starstar [',']]] | vfpdef_starstar [','])"
),
)
def convert_argslist(config: ParserConfig, children: Sequence[Any]) -> Any:
params: List[Param] = []
default_params: List[Param] = []
star_arg: Union[Param, ParamStar, MaybeSentinel] = MaybeSentinel.DEFAULT
kwonly_params: List[Param] = []
star_kwarg: Optional[Param] = None
def add_param(
current_param: Optional[List[Param]], param: Union[Param, ParamStar]
) -> Optional[List[Param]]:
nonlocal star_arg
nonlocal star_kwarg
if isinstance(param, ParamStar):
# Only can add this if we don't already have a "*" or a "*param".
if current_param in [params, default_params]:
star_arg = param
current_param = kwonly_params
else:
# TODO: We need to inform the user of an invalid syntax here
raise Exception("Syntax error!")
elif isinstance(param.star, str) and param.star == "" and param.default is None:
# Can only add this if we're in the params or kwonly_params section
if current_param is params:
params.append(param)
elif current_param is kwonly_params:
kwonly_params.append(param)
else:
# TODO: We need to inform the user of an invalid syntax here
raise Exception("Syntax error!")
elif (
isinstance(param.star, str)
and param.star == ""
and param.default is not None
):
if current_param is params:
current_param = default_params
# Can only add this if we're not yet at star args.
if current_param is default_params:
default_params.append(param)
elif current_param is kwonly_params:
kwonly_params.append(param)
else:
# TODO: We need to inform the user of an invalid syntax here
raise Exception("Syntax error!")
elif (
isinstance(param.star, str) and param.star == "*" and param.default is None
):
# Can only add this if we're in params/default_params, since
# we only allow one of "*" or "*param".
if current_param in [params, default_params]:
star_arg = param
current_param = kwonly_params
else:
# TODO: We need to inform the user of an invalid syntax here
raise Exception("Syntax error!")
elif (
isinstance(param.star, str) and param.star == "**" and param.default is None
):
# Can add this in all cases where we don't have a star_kwarg
# yet.
if current_param is not None:
star_kwarg = param
current_param = None
else:
# TODO: We need to inform the user of an invalid syntax here
raise Exception("Syntax error!")
else:
# TODO: We need to inform the user of an invalid syntax here
raise Exception("Syntax error!")
return current_param
# The parameter list we are adding to
current: Optional[List[Param]] = params
# We should have every other item in the group as a param or a comma by now,
# so split them up, add commas and then put them in the appropriate group.
for parameter, comma in grouper(children, 2):
if comma is None:
if isinstance(parameter, ParamStarPartial):
# TODO: We need to inform the user of an invalid syntax here
raise Exception("Syntax error!")
else:
current = add_param(current, parameter)
else:
comma = Comma(
whitespace_before=parse_parenthesizable_whitespace(
config, comma.whitespace_before
),
whitespace_after=parse_parenthesizable_whitespace(
config, comma.whitespace_after
),
)
if isinstance(parameter, ParamStarPartial):
current = add_param(current, ParamStar(comma=comma))
else:
current = add_param(current, parameter.with_changes(comma=comma))
return Parameters(
params=tuple(params),
default_params=tuple(default_params),
star_arg=star_arg,
kwonly_params=tuple(kwonly_params),
star_kwarg=star_kwarg,
)
@with_production("tfpdef_star", "'*' [tfpdef]")
@with_production("vfpdef_star", "'*' [vfpdef]")
def convert_fpdef_star(config: ParserConfig, children: Sequence[Any]) -> Any:
if len(children) == 1:
(star,) = children
return ParamStarPartial()
else:
star, param = children
return param.with_changes(
star=star.string,
whitespace_after_star=parse_parenthesizable_whitespace(
config, star.whitespace_after
),
)
@with_production("tfpdef_starstar", "'**' tfpdef")
@with_production("vfpdef_starstar", "'**' vfpdef")
def convert_fpdef_starstar(config: ParserConfig, children: Sequence[Any]) -> Any:
starstar, param = children
return param.with_changes(
star=starstar.string,
whitespace_after_star=parse_parenthesizable_whitespace(
config, starstar.whitespace_after
),
)
@with_production("tfpdef_assign", "tfpdef ['=' test]")
@with_production("vfpdef_assign", "vfpdef ['=' test]")
def convert_fpdef_assign(config: ParserConfig, children: Sequence[Any]) -> Any:
if len(children) == 1:
(child,) = children
return child
param, equal, default = children
return param.with_changes(
equal=AssignEqual(
whitespace_before=parse_parenthesizable_whitespace(
config, equal.whitespace_before
),
whitespace_after=parse_parenthesizable_whitespace(
config, equal.whitespace_after
),
),
default=default.value,
)
@with_production("tfpdef", "NAME [':' test]")
@with_production("vfpdef", "NAME")
def convert_fpdef(config: ParserConfig, children: Sequence[Any]) -> Any:
if len(children) == 1:
# This is just a parameter
(child,) = children
namenode = Name(child.string)
annotation = None
else:
# This is a parameter with a type hint
name, colon, typehint = children
namenode = Name(name.string)
annotation = Annotation(
whitespace_before_indicator=parse_parenthesizable_whitespace(
config, colon.whitespace_before
),
indicator=":",
whitespace_after_indicator=parse_parenthesizable_whitespace(
config, colon.whitespace_after
),
annotation=typehint.value,
)
return Param(star="", name=namenode, annotation=annotation, default=None)