# Licensed under the LGPL: https://www.gnu.org/licenses/old-licenses/lgpl-2.1.en.html
# For details: https://github.com/PyCQA/astroid/blob/main/LICENSE
# Copyright (c) https://github.com/PyCQA/astroid/blob/main/CONTRIBUTORS.txt
from __future__ import annotations
from astroid import context, inference_tip, nodes
from astroid.brain.helpers import register_module_extender
from astroid.builder import _extract_single_node, parse
from astroid.const import PY39_PLUS
from astroid.manager import AstroidManager
def _regex_transform() -> nodes.Module:
"""The RegexFlag enum exposes all its entries by updating globals().
We hard-code the flags for now.
# pylint: disable-next=line-too-long
See https://github.com/mrabarnett/mrab-regex/blob/2022.10.31/regex_3/regex.py#L200
"""
return parse(
"""
A = ASCII = 0x80 # Assume ASCII locale.
B = BESTMATCH = 0x1000 # Best fuzzy match.
D = DEBUG = 0x200 # Print parsed pattern.
E = ENHANCEMATCH = 0x8000 # Attempt to improve the fit after finding the first
# fuzzy match.
F = FULLCASE = 0x4000 # Unicode full case-folding.
I = IGNORECASE = 0x2 # Ignore case.
L = LOCALE = 0x4 # Assume current 8-bit locale.
M = MULTILINE = 0x8 # Make anchors look for newline.
P = POSIX = 0x10000 # POSIX-style matching (leftmost longest).
R = REVERSE = 0x400 # Search backwards.
S = DOTALL = 0x10 # Make dot match newline.
U = UNICODE = 0x20 # Assume Unicode locale.
V0 = VERSION0 = 0x2000 # Old legacy behaviour.
DEFAULT_VERSION = V0
V1 = VERSION1 = 0x100 # New enhanced behaviour.
W = WORD = 0x800 # Default Unicode word breaks.
X = VERBOSE = 0x40 # Ignore whitespace and comments.
T = TEMPLATE = 0x1 # Template (present because re module has it).
"""
)
register_module_extender(AstroidManager(), "regex", _regex_transform)
CLASS_GETITEM_TEMPLATE = """
@classmethod
def __class_getitem__(cls, item):
return cls
"""
def _looks_like_pattern_or_match(node: nodes.Call) -> bool:
"""Check for regex.Pattern or regex.Match call in stdlib.
Match these patterns from stdlib/re.py
```py
Pattern = type(...)
Match = type(...)
```
"""
return (
node.root().name == "regex.regex"
and isinstance(node.func, nodes.Name)
and node.func.name == "type"
and isinstance(node.parent, nodes.Assign)
and len(node.parent.targets) == 1
and isinstance(node.parent.targets[0], nodes.AssignName)
and node.parent.targets[0].name in {"Pattern", "Match"}
)
def infer_pattern_match(node: nodes.Call, ctx: context.InferenceContext | None = None):
"""Infer regex.Pattern and regex.Match as classes.
For PY39+ add `__class_getitem__`.
"""
class_def = nodes.ClassDef(
name=node.parent.targets[0].name,
lineno=node.lineno,
col_offset=node.col_offset,
parent=node.parent,
)
if PY39_PLUS:
func_to_add = _extract_single_node(CLASS_GETITEM_TEMPLATE)
class_def.locals["__class_getitem__"] = [func_to_add]
return iter([class_def])
AstroidManager().register_transform(
nodes.Call, inference_tip(infer_pattern_match), _looks_like_pattern_or_match
)
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