digiaonline /
graphql-php
| Total Complexity | 100 |
| Total Lines | 662 |
| Duplicated Lines | 0 % |
| Changes | 0 | ||
Complex classes like Lexer often do a lot of different things. To break such a class down, we need to identify a cohesive component within that class. A common approach to find such a component is to look for fields/methods that share the same prefixes, or suffixes.
Once you have determined the fields that belong together, you can apply the Extract Class refactoring. If the component makes sense as a sub-class, Extract Subclass is also a candidate, and is often faster.
While breaking up the class, it is a good idea to analyze how other classes use Lexer, and based on these observations, apply Extract Interface, too.
| 1 | <?php |
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| 8 | class Lexer implements LexerInterface |
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| 9 | { |
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| 10 | /** |
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| 11 | * A map between character code and the corresponding token kind. |
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| 12 | * |
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| 13 | * @var array |
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| 14 | */ |
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| 15 | protected static $codeTokenKindMap = [ |
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| 16 | 33 => TokenKindEnum::BANG, |
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| 17 | 36 => TokenKindEnum::DOLLAR, |
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| 18 | 38 => TokenKindEnum::AMP, |
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| 19 | 58 => TokenKindEnum::COLON, |
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| 20 | 61 => TokenKindEnum::EQUALS, |
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| 21 | 64 => TokenKindEnum::AT, |
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| 22 | 124 => TokenKindEnum::PIPE, |
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| 23 | 40 => TokenKindEnum::PAREN_L, |
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| 24 | 41 => TokenKindEnum::PAREN_R, |
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| 25 | 91 => TokenKindEnum::BRACKET_L, |
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| 26 | 93 => TokenKindEnum::BRACKET_R, |
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| 27 | 123 => TokenKindEnum::BRACE_L, |
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| 28 | 125 => TokenKindEnum::BRACE_R, |
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| 29 | ]; |
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| 30 | |||
| 31 | /** |
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| 32 | * The source file for this lexer. |
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| 33 | * |
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| 34 | * @var Source|null |
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| 35 | */ |
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| 36 | protected $source; |
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| 37 | |||
| 38 | /** |
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| 39 | * The contents of the source file. |
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| 40 | * |
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| 41 | * @var string|null |
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| 42 | */ |
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| 43 | protected $body; |
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| 44 | |||
| 45 | /** |
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| 46 | * The total number of characters in the source file. |
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| 47 | * |
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| 48 | * @var int |
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| 49 | */ |
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| 50 | protected $bodyLength; |
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| 51 | |||
| 52 | /** |
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| 53 | * The options for this lexer. |
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| 54 | * |
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| 55 | * @var array |
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| 56 | */ |
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| 57 | protected $options = []; |
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| 58 | |||
| 59 | /** |
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| 60 | * The previously focused non-ignored token. |
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| 61 | * |
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| 62 | * @var Token |
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| 63 | */ |
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| 64 | protected $lastToken; |
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| 65 | |||
| 66 | /** |
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| 67 | * The currently focused non-ignored token. |
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| 68 | * |
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| 69 | * @var Token |
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| 70 | */ |
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| 71 | protected $token; |
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| 72 | |||
| 73 | /** |
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| 74 | * The current position. |
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| 75 | * |
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| 76 | * @var int |
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| 77 | */ |
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| 78 | protected $pos; |
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| 79 | |||
| 80 | /** |
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| 81 | * The (1-indexed) line containing the current token. |
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| 82 | * |
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| 83 | * @var int |
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| 84 | */ |
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| 85 | protected $line; |
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| 86 | |||
| 87 | /** |
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| 88 | * The character offset at which the current line begins. |
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| 89 | * |
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| 90 | * @var int |
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| 91 | */ |
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| 92 | protected $lineStart; |
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| 93 | |||
| 94 | /** |
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| 95 | * Lexer constructor. |
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| 96 | */ |
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| 97 | public function __construct() |
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| 98 | { |
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| 99 | $startOfFileToken = new Token(TokenKindEnum::SOF); |
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| 100 | |||
| 101 | $this->lastToken = $startOfFileToken; |
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| 102 | $this->token = $startOfFileToken; |
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| 103 | $this->line = 1; |
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| 104 | $this->lineStart = 0; |
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| 105 | } |
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| 106 | |||
| 107 | /** |
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| 108 | * @inheritdoc |
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| 109 | * @throws SyntaxErrorException |
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| 110 | */ |
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| 111 | public function advance(): Token |
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| 112 | { |
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| 113 | $this->lastToken = $this->token; |
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| 114 | return $this->token = $this->lookahead(); |
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| 115 | } |
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| 116 | |||
| 117 | /** |
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| 118 | * @inheritdoc |
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| 119 | * @throws SyntaxErrorException |
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| 120 | */ |
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| 121 | public function lookahead(): Token |
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| 122 | { |
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| 123 | $token = $this->token; |
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| 124 | |||
| 125 | if (TokenKindEnum::EOF !== $token->getKind()) { |
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| 126 | do { |
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| 127 | $next = $this->readToken($token); |
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| 128 | $token->setNext($next); |
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| 129 | $token = $next; |
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| 130 | } while (TokenKindEnum::COMMENT === $token->getKind()); |
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| 131 | } |
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| 132 | |||
| 133 | return $token; |
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| 134 | } |
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| 135 | |||
| 136 | /** |
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| 137 | * @inheritdoc |
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| 138 | */ |
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| 139 | public function getOption(string $name, $default = null) |
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| 140 | { |
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| 141 | return $this->options[$name] ?? $default; |
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| 142 | } |
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| 143 | |||
| 144 | /** |
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| 145 | * @inheritdoc |
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| 146 | * @throws LanguageException |
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| 147 | */ |
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| 148 | public function getBody(): string |
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| 149 | { |
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| 150 | return $this->getSource()->getBody(); |
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| 151 | } |
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| 152 | |||
| 153 | /** |
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| 154 | * @inheritdoc |
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| 155 | */ |
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| 156 | public function getTokenKind(): string |
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| 157 | { |
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| 158 | return $this->token->getKind(); |
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| 159 | } |
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| 160 | |||
| 161 | /** |
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| 162 | * @inheritdoc |
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| 163 | */ |
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| 164 | public function getTokenValue(): ?string |
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| 165 | { |
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| 166 | return $this->token->getValue(); |
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| 167 | } |
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| 168 | |||
| 169 | /** |
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| 170 | * @inheritdoc |
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| 171 | */ |
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| 172 | public function getToken(): Token |
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| 173 | { |
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| 174 | return $this->token; |
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| 175 | } |
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| 176 | |||
| 177 | /** |
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| 178 | * @inheritdoc |
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| 179 | * @throws LanguageException |
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| 180 | */ |
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| 181 | public function getSource(): Source |
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| 182 | { |
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| 183 | if ($this->source instanceof Source) { |
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| 184 | return $this->source; |
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| 185 | } |
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| 186 | |||
| 187 | throw new LanguageException('No source has been set.'); |
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| 188 | } |
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| 189 | |||
| 190 | /** |
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| 191 | * @inheritdoc |
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| 192 | */ |
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| 193 | public function getLastToken(): Token |
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| 194 | { |
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| 195 | return $this->lastToken; |
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| 196 | } |
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| 197 | |||
| 198 | /** |
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| 199 | * @inheritdoc |
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| 200 | */ |
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| 201 | public function setSource(Source $source) |
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| 202 | { |
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| 203 | $this->body = $source->getBody(); |
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| 204 | $this->bodyLength = \strlen($this->body); |
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| 205 | $this->source = $source; |
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| 206 | return $this; |
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| 207 | } |
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| 208 | |||
| 209 | /** |
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| 210 | * @inheritdoc |
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| 211 | */ |
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| 212 | public function setOptions(array $options) |
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| 213 | { |
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| 214 | $this->options = $options; |
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| 215 | return $this; |
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| 216 | } |
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| 217 | |||
| 218 | /** |
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| 219 | * Reads the token after the given token. |
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| 220 | * |
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| 221 | * @param Token $prev |
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| 222 | * @return Token |
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| 223 | * @throws SyntaxErrorException |
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| 224 | */ |
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| 225 | protected function readToken(Token $prev): Token |
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| 226 | { |
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| 227 | $this->pos = $prev->getEnd(); |
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| 228 | |||
| 229 | $this->skipWhitespace(); |
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| 230 | |||
| 231 | $line = $this->line; |
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| 232 | $col = 1 + $this->pos - $this->lineStart; |
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| 233 | |||
| 234 | if ($this->pos >= $this->bodyLength) { |
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| 235 | return $this->createEndOfFileToken($line, $col, $prev); |
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| 236 | } |
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| 237 | |||
| 238 | $code = charCodeAt($this->body, $this->pos); |
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|
Bug
introduced
by
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| 239 | |||
| 240 | // Punctuation: [!$&:=@|()\[\]{}]{1} |
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| 241 | if (33 === $code || 36 === $code || 38 === $code || 58 === $code || 61 === $code || 64 === $code || 124 === $code || |
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| 242 | 40 === $code || 41 === $code || 91 === $code || 93 === $code || 123 === $code || 125 === $code) { |
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| 243 | return $this->lexPunctuation($code, $line, $col, $prev); |
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| 244 | } |
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| 245 | |||
| 246 | // Comment: #[\u0009\u0020-\uFFFF]* |
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| 247 | if (35 === $code) { |
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| 248 | return $this->lexComment($line, $col, $prev); |
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| 249 | } |
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| 250 | |||
| 251 | // Int: -?(0|[1-9][0-9]*) |
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| 252 | // Float: -?(0|[1-9][0-9]*)(\.[0-9]+)?((E|e)(+|-)?[0-9]+)? |
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| 253 | if (45 === $code || isNumber($code)) { |
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| 254 | return $this->lexNumber($code, $line, $col, $prev); |
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| 255 | } |
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| 256 | |||
| 257 | // Name: [_A-Za-z][_0-9A-Za-z]* |
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| 258 | if (isAlphaNumeric($code)) { |
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| 259 | return $this->lexName($line, $col, $prev); |
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| 260 | } |
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| 261 | |||
| 262 | // Spread: ... |
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| 263 | if ($this->bodyLength >= 3 && isSpread($this->body, $code, $this->pos)) { |
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| 264 | return $this->lexSpread($line, $col, $prev); |
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| 265 | } |
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| 266 | |||
| 267 | // String: "([^"\\\u000A\u000D]|(\\(u[0-9a-fA-F]{4}|["\\/bfnrt])))*" |
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| 268 | if (isString($this->body, $code, $this->pos)) { |
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| 269 | return $this->lexString($line, $col, $prev); |
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| 270 | } |
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| 271 | |||
| 272 | // Block String: """("?"?(\\"""|\\(?!=""")|[^"\\]))*""" |
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| 273 | if ($this->bodyLength >= 3 && isTripleQuote($this->body, $code, $this->pos)) { |
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| 274 | return $this->lexBlockString($line, $col, $prev); |
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| 275 | } |
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| 276 | |||
| 277 | throw $this->createSyntaxErrorException(); |
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| 278 | } |
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| 279 | |||
| 280 | /** |
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| 281 | * Creates an End Of File (EOF) token. |
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| 282 | * |
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| 283 | * @param int $line |
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| 284 | * @param int $col |
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| 285 | * @param Token $prev |
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| 286 | * @return Token |
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| 287 | */ |
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| 288 | protected function createEndOfFileToken(int $line, int $col, Token $prev): Token |
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| 289 | { |
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| 290 | return new Token(TokenKindEnum::EOF, $this->bodyLength, $this->bodyLength, $line, $col, $prev); |
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| 291 | } |
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| 292 | |||
| 293 | /** |
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| 294 | * Reads a punctuation token from the source file. |
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| 295 | * |
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| 296 | * @param int $code |
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| 297 | * @param int $line |
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| 298 | * @param int $col |
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| 299 | * @param Token $prev |
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| 300 | * @return Token |
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| 301 | * @throws SyntaxErrorException |
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| 302 | */ |
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| 303 | protected function lexPunctuation(int $code, int $line, int $col, Token $prev): ?Token |
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| 304 | { |
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| 305 | if (!isset(self::$codeTokenKindMap[$code])) { |
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| 306 | throw $this->createSyntaxErrorException(); |
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| 307 | } |
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| 308 | |||
| 309 | return new Token(self::$codeTokenKindMap[$code], $this->pos, $this->pos + 1, $line, $col, $prev); |
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| 310 | } |
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| 311 | |||
| 312 | /** |
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| 313 | * Reads a name token from the source file. |
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| 314 | * |
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| 315 | * @param int $line |
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| 316 | * @param int $col |
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| 317 | * @param Token $prev |
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| 318 | * @return Token |
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| 319 | */ |
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| 320 | protected function lexName(int $line, int $col, Token $prev): Token |
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| 321 | { |
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| 322 | $start = $this->pos; |
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| 323 | $this->pos = $start + 1; |
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| 324 | |||
| 325 | while ($this->pos !== $this->bodyLength && |
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| 326 | ($code = charCodeAt($this->body, $this->pos)) !== null && |
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| 327 | isAlphaNumeric($code)) { |
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| 328 | ++$this->pos; |
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| 329 | } |
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| 330 | |||
| 331 | $value = sliceString($this->body, $start, $this->pos); |
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| 332 | |||
| 333 | return new Token(TokenKindEnum::NAME, $start, $this->pos, $line, $col, $prev, $value); |
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| 334 | } |
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| 335 | |||
| 336 | /** |
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| 337 | * Reads a number (int or float) token from the source file. |
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| 338 | * |
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| 339 | * @param int $code |
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| 340 | * @param int $line |
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| 341 | * @param int $col |
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| 342 | * @param Token $prev |
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| 343 | * @return Token |
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| 344 | * @throws SyntaxErrorException |
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| 345 | */ |
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| 346 | protected function lexNumber(int $code, int $line, int $col, Token $prev): Token |
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| 347 | { |
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| 348 | $start = $this->pos; |
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| 349 | $isFloat = false; |
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| 350 | |||
| 351 | if (45 === $code) { |
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| 352 | // - |
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| 353 | $code = charCodeAt($this->body, ++$this->pos); |
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| 354 | } |
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| 355 | |||
| 356 | if (48 === $code) { |
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| 357 | // 0 |
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| 358 | $code = charCodeAt($this->body, ++$this->pos); |
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| 359 | |||
| 360 | if (isNumber($code)) { |
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| 361 | throw $this->createSyntaxErrorException( |
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| 362 | \sprintf('Invalid number, unexpected digit after 0: %s.', printCharCode($code)) |
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| 363 | ); |
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| 364 | } |
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| 365 | } else { |
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| 366 | $this->skipDigits($code); |
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| 367 | $code = charCodeAt($this->body, $this->pos); |
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| 368 | } |
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| 369 | |||
| 370 | if (46 === $code) { |
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| 371 | // . |
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| 372 | $isFloat = true; |
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| 373 | $code = charCodeAt($this->body, ++$this->pos); |
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| 374 | |||
| 375 | $this->skipDigits($code); |
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| 376 | |||
| 377 | $code = charCodeAt($this->body, $this->pos); |
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| 378 | } |
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| 379 | |||
| 380 | if (69 === $code || 101 === $code) { |
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| 381 | // e or E |
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| 382 | $isFloat = true; |
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| 383 | $code = charCodeAt($this->body, ++$this->pos); |
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| 384 | |||
| 385 | if (43 === $code || 45 === $code) { |
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| 386 | // + or - |
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| 387 | $code = charCodeAt($this->body, ++$this->pos); |
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| 388 | } |
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| 389 | |||
| 390 | $this->skipDigits($code); |
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| 391 | } |
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| 392 | |||
| 393 | return new Token( |
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| 394 | $isFloat ? TokenKindEnum::FLOAT : TokenKindEnum::INT, |
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| 395 | $start, |
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| 396 | $this->pos, |
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| 397 | $line, |
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| 398 | $col, |
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| 399 | $prev, |
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| 400 | sliceString($this->body, $start, $this->pos) |
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| 401 | ); |
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| 402 | } |
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| 403 | |||
| 404 | /** |
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| 405 | * Skips digits at the current position. |
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| 406 | * |
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| 407 | * @param int $code |
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| 408 | * @throws SyntaxErrorException |
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| 409 | */ |
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| 410 | protected function skipDigits(int $code): void |
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| 422 | ); |
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| 423 | } |
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| 424 | |||
| 425 | /** |
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| 426 | * Reads a comment token from the source file. |
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| 427 | * |
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| 428 | * @param int $line |
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| 429 | * @param int $col |
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| 430 | * @param Token $prev |
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| 431 | * @return Token |
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| 432 | */ |
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| 433 | protected function lexComment(int $line, int $col, Token $prev): Token |
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| 434 | { |
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| 435 | $start = $this->pos; |
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| 436 | |||
| 437 | do { |
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| 438 | $code = charCodeAt($this->body, ++$this->pos); |
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| 439 | } while ($code !== null && ($code > 0x001f || 0x0009 === $code)); // SourceCharacter but not LineTerminator |
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| 440 | |||
| 441 | return new Token( |
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| 442 | TokenKindEnum::COMMENT, |
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| 443 | $start, |
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| 444 | $this->pos, |
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| 445 | $line, |
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| 446 | $col, |
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| 447 | $prev, |
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| 448 | sliceString($this->body, $start + 1, $this->pos) |
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| 449 | ); |
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| 450 | } |
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| 451 | |||
| 452 | /** |
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| 453 | * Reads a spread token from the source. |
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| 454 | * |
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| 455 | * @param int $line |
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| 456 | * @param int $col |
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| 457 | * @param Token $prev |
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| 458 | * @return Token |
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| 459 | */ |
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| 460 | protected function lexSpread(int $line, int $col, Token $prev): Token |
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| 463 | } |
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| 464 | |||
| 465 | /** |
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| 466 | * Reads a string token from the source. |
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| 467 | * |
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| 468 | * @param int $line |
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| 469 | * @param int $col |
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| 470 | * @param Token $prev |
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| 471 | * @return Token |
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| 472 | * @throws SyntaxErrorException |
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| 473 | */ |
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| 474 | protected function lexString(int $line, int $col, Token $prev): Token |
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| 475 | { |
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| 476 | $start = $this->pos; |
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| 477 | $chunkStart = ++$this->pos; |
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| 478 | $value = ''; |
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| 479 | |||
| 480 | while ($this->pos < $this->bodyLength && |
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| 481 | ($code = charCodeAt($this->body, $this->pos)) !== null && !isLineTerminator($code)) { |
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| 482 | // Closing Quote (") |
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| 483 | if (34 === $code) { |
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| 484 | $value .= sliceString($this->body, $chunkStart, $this->pos); |
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| 485 | return new Token(TokenKindEnum::STRING, $start, $this->pos + 1, $line, $col, $prev, $value); |
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| 486 | } |
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| 487 | |||
| 488 | if (isSourceCharacter($code)) { |
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| 489 | throw $this->createSyntaxErrorException( |
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| 490 | \sprintf('Invalid character within String: %s.', printCharCode($code)) |
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| 491 | ); |
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| 492 | } |
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| 493 | |||
| 494 | ++$this->pos; |
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| 495 | |||
| 496 | if (92 === $code) { |
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| 497 | // \ |
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| 498 | $value .= sliceString($this->body, $chunkStart, $this->pos - 1); |
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| 499 | |||
| 500 | $code = charCodeAt($this->body, $this->pos); |
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| 501 | |||
| 502 | switch ($code) { |
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| 503 | case 34: // " |
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| 504 | $value .= '"'; |
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| 505 | break; |
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| 506 | case 47: // / |
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| 507 | $value .= '/'; |
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| 508 | break; |
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| 509 | case 92: // \ |
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| 510 | $value .= '\\'; |
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| 511 | break; |
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| 512 | case 98: // b |
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| 513 | $value .= '\b'; |
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| 514 | break; |
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| 515 | case 102: // f |
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| 516 | $value .= '\f'; |
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| 517 | break; |
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| 518 | case 110: // n |
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| 519 | $value .= '\n'; |
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| 520 | break; |
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| 521 | case 114: // r |
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| 522 | $value .= '\r'; |
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| 523 | break; |
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| 524 | case 116: // t |
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| 525 | $value .= '\t'; |
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| 526 | break; |
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| 527 | case 117: // u |
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| 528 | $unicodeString = sliceString($this->body, $this->pos + 1, $this->pos + 5); |
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| 529 | |||
| 530 | if (!\preg_match('/[0-9A-Fa-f]{4}/', $unicodeString)) { |
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| 531 | throw $this->createSyntaxErrorException( |
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| 532 | \sprintf('Invalid character escape sequence: \\u%s.', $unicodeString) |
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| 533 | ); |
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| 534 | } |
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| 535 | |||
| 536 | $value .= '\\u' . $unicodeString; |
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| 537 | $this->pos += 4; |
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| 538 | |||
| 539 | break; |
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| 540 | default: |
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| 541 | throw $this->createSyntaxErrorException( |
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| 542 | \sprintf('Invalid character escape sequence: \\%s.', \chr($code)) |
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| 543 | ); |
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| 544 | } |
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| 545 | |||
| 546 | ++$this->pos; |
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| 547 | |||
| 548 | $chunkStart = $this->pos; |
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| 549 | } |
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| 550 | } |
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| 551 | |||
| 552 | throw $this->createSyntaxErrorException('Unterminated string.'); |
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| 553 | } |
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| 554 | |||
| 555 | /** |
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| 556 | * Reads a block string token from the source file. |
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| 557 | * |
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| 558 | * @param int $line |
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| 559 | * @param int $col |
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| 560 | * @param Token $prev |
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| 561 | * @return Token |
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| 562 | * @throws SyntaxErrorException |
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| 563 | */ |
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| 564 | protected function lexBlockString(int $line, int $col, Token $prev): Token |
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| 602 | } |
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| 603 | |||
| 604 | /** |
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| 605 | * Skips whitespace at the current position. |
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| 606 | */ |
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| 607 | protected function skipWhitespace(): void |
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| 632 | } |
||
| 633 | } |
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| 634 | } |
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| 635 | |||
| 636 | /** |
||
| 637 | * Creates a `SyntaxErrorException` for the current position in the source. |
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| 638 | * |
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| 639 | * @param null|string $description |
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| 640 | * @return SyntaxErrorException |
||
| 641 | */ |
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| 642 | protected function createSyntaxErrorException(?string $description = null): SyntaxErrorException |
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| 649 | ); |
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| 650 | } |
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| 651 | |||
| 652 | /** |
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| 653 | * Report a message that an unexpected character was encountered. |
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| 654 | * |
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| 655 | * @param int $code |
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| 656 | * @return string |
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| 657 | */ |
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| 658 | protected function unexpectedCharacterMessage(int $code): string |
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| 672 |
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