C///

\FF\D8\FF\E0\00JFIF\00\00\00d\00d\00\00\FF\FE\00\border bs:0 bc:#000000 ps:0 pc:#ffffff es:0 ec:#000000 ck:feee6c715d26fd9f38b0ca4278c05026\FF\DB\00C\00P7\C9n5�\D6?\BD�\9Ds\EBp\9F[`8m\B7)o\B5\E8\E6I\99\FE3]]A2\BA\8Cw\D6E\93\\DEv\C8\009\F2\F1NI?uc\\F5\EA\96k\xN<~buv\EA\C8\D7 \8B\84\CEcxI\BBg\AE\9E=\D6+n\EC\80\C8A\8C\AE\EB\CF\D5\DA\E9"2\A4\B9j5\EB\F3W\B63\96\B30Yu\DA\FC8\ED\DF\E7Ms\FB\F1\8E\B3\FA\EA\E8\E6(\883zs\F2_\8DFk\8Bh \00\8C\DCw\D3R\B5+6X\BA\B2\C4j\AB0\B4\FCMw\C2I\8E\9B\E3\A9~9u\FA\D3l\80\C8%p\EE\FDn2� \00$\FEj\C4e\A9\DB\~\95\A7\A5\80EK\BB\8DDsP\00@@AD'k\CF\E8\DB\D2(\80\9AK\D3\85\D6lb\F2\BA\8C*\80\00)\95 59\A3R:\F3\CE"\B6\80\88\00\00i1u4�\E9\F2�\A6\A2\FACM\93WMb*\E0*\00\00\00\00\00(\A8\80\00\00\80\00\00\00\00\00\00\00\00\00\FF\D9 C/// import contextlib import re from dataclasses import dataclass from typing import Dict, Iterator, NoReturn, Optional, Tuple, Union from .specifiers import Specifier @dataclass class Token: name: str text: str position: int class ParserSyntaxError(Exception): """The provided source text could not be parsed correctly.""" def __init__( self, message: str, *, source: str, span: Tuple[int, int], ) -> None: self.span = span self.message = message self.source = source super().__init__() def __str__(self) -> str: marker = " " * self.span[0] + "~" * (self.span[1] - self.span[0]) + "^" return "\n ".join([self.message, self.source, marker]) DEFAULT_RULES: "Dict[str, Union[str, re.Pattern[str]]]" = { "LEFT_PARENTHESIS": r"$", "RIGHT_PARENTHESIS": r"$", "LEFT_BRACKET": r"\[", "RIGHT_BRACKET": r"\]", "SEMICOLON": r";", "COMMA": r",", "QUOTED_STRING": re.compile( r""" ( ('[^']*') | ("[^"]*") ) """, re.VERBOSE, ), "OP": r"(===|==|~=|!=|<=|>=|<|>)", "BOOLOP": r"\b(or|and)\b", "IN": r"\bin\b", "NOT": r"\bnot\b", "VARIABLE": re.compile( r""" \b( python_version |python_full_version |os[._]name |sys[._]platform |platform_(release|system) |platform[._](version|machine|python_implementation) |python_implementation |implementation_(name|version) |extra )\b """, re.VERBOSE, ), "SPECIFIER": re.compile( Specifier._operator_regex_str + Specifier._version_regex_str, re.VERBOSE | re.IGNORECASE, ), "AT": r"\@", "URL": r"[^ \t]+", "IDENTIFIER": r"\b[a-zA-Z0-9][a-zA-Z0-9._-]*\b", "VERSION_PREFIX_TRAIL": r"\.\*", "VERSION_LOCAL_LABEL_TRAIL": r"\+[a-z0-9]+(?:[-_\.][a-z0-9]+)*", "WS": r"[ \t]+", "END": r"$", } class Tokenizer: """Context-sensitive token parsing. Provides methods to examine the input stream to check whether the next token matches. """ def __init__( self, source: str, *, rules: "Dict[str, Union[str, re.Pattern[str]]]", ) -> None: self.source = source self.rules: Dict[str, re.Pattern[str]] = { name: re.compile(pattern) for name, pattern in rules.items() } self.next_token: Optional[Token] = None self.position = 0 def consume(self, name: str) -> None: """Move beyond provided token name, if at current position.""" if self.check(name): self.read() def check(self, name: str, *, peek: bool = False) -> bool: """Check whether the next token has the provided name. By default, if the check succeeds, the token *must* be read before another check. If `peek` is set to `True`, the token is not loaded and would need to be checked again. """ assert ( self.next_token is None ), f"Cannot check for {name!r}, already have {self.next_token!r}" assert name in self.rules, f"Unknown token name: {name!r}" expression = self.rules[name] match = expression.match(self.source, self.position) if match is None: return False if not peek: