| 78 | self.current = next(self.tokens) |
| 79 | |
| 80 | def lex(self, input: str) -> Iterator[Token]: |
| 81 | pos = 0 |
| 82 | while pos < len(input): |
| 83 | if input[pos] in (" ", "\t"): |
| 84 | pos += 1 |
| 85 | elif input[pos] == "(": |
| 86 | yield Token(TokenType.LPAREN, "(", pos) |
| 87 | pos += 1 |
| 88 | elif input[pos] == ")": |
| 89 | yield Token(TokenType.RPAREN, ")", pos) |
| 90 | pos += 1 |
| 91 | elif input[pos] == "=": |
| 92 | yield Token(TokenType.EQUAL, "=", pos) |
| 93 | pos += 1 |
| 94 | elif input[pos] == ",": |
| 95 | yield Token(TokenType.COMMA, ",", pos) |
| 96 | pos += 1 |
| 97 | elif (quote_char := input[pos]) in ("'", '"'): |
| 98 | end_quote_pos = input.find(quote_char, pos + 1) |
| 99 | if end_quote_pos == -1: |
| 100 | raise SyntaxError( |
| 101 | f'closing quote "{quote_char}" is missing', |
| 102 | (FILE_NAME, 1, pos + 1, input), |
| 103 | ) |
| 104 | value = input[pos : end_quote_pos + 1] |
| 105 | if (backslash_pos := value.find("\\")) != -1: |
| 106 | raise SyntaxError( |
| 107 | r'escaping with "\" not supported in marker expression', |
| 108 | (FILE_NAME, 1, pos + backslash_pos + 1, input), |
| 109 | ) |
| 110 | yield Token(TokenType.STRING, value, pos) |
| 111 | pos += len(value) |
| 112 | else: |
| 113 | match = re.match(r"(:?\w|:|\+|-|\.|\[|\]|\\|/)+", input[pos:]) |
| 114 | if match: |
| 115 | value = match.group(0) |
| 116 | if value == "or": |
| 117 | yield Token(TokenType.OR, value, pos) |
| 118 | elif value == "and": |
| 119 | yield Token(TokenType.AND, value, pos) |
| 120 | elif value == "not": |
| 121 | yield Token(TokenType.NOT, value, pos) |
| 122 | else: |
| 123 | yield Token(TokenType.IDENT, value, pos) |
| 124 | pos += len(value) |
| 125 | else: |
| 126 | raise SyntaxError( |
| 127 | f'unexpected character "{input[pos]}"', |
| 128 | (FILE_NAME, 1, pos + 1, input), |
| 129 | ) |
| 130 | yield Token(TokenType.EOF, "", pos) |
| 131 | |
| 132 | @overload |
| 133 | def accept(self, type: TokenType, *, reject: Literal[True]) -> Token: ... |