digiaonline /
graphql-php
| Total Complexity | 111 |
| Total Lines | 697 |
| 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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| 7 | class Lexer implements LexerInterface |
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| 8 | { |
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| 9 | protected const ENCODING = 'UTF-8'; |
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| 10 | |||
| 11 | /** |
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| 12 | * A map between punctuation character code and the corresponding token kind. |
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| 13 | * |
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| 14 | * @var array |
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| 15 | */ |
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| 16 | protected static $codeTokenKindMap = [ |
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| 17 | 33 => TokenKindEnum::BANG, |
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| 18 | 36 => TokenKindEnum::DOLLAR, |
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| 19 | 38 => TokenKindEnum::AMP, |
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| 20 | 40 => TokenKindEnum::PAREN_L, |
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| 21 | 41 => TokenKindEnum::PAREN_R, |
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| 22 | 58 => TokenKindEnum::COLON, |
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| 23 | 61 => TokenKindEnum::EQUALS, |
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| 24 | 64 => TokenKindEnum::AT, |
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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 | 124 => TokenKindEnum::PIPE, |
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| 29 | 125 => TokenKindEnum::BRACE_R, |
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| 30 | ]; |
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| 31 | |||
| 32 | /** |
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| 33 | * The source file for this lexer. |
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| 34 | * |
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| 35 | * @var Source |
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| 36 | */ |
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| 37 | protected $source; |
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| 38 | |||
| 39 | /** |
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| 40 | * The contents of the source file. |
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| 41 | * |
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| 42 | * @var string |
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| 43 | */ |
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| 44 | protected $body; |
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| 45 | |||
| 46 | /** |
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| 47 | * The total number of characters in the source file. |
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| 48 | * |
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| 49 | * @var int |
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| 50 | */ |
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| 51 | protected $bodyLength; |
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| 52 | |||
| 53 | /** |
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| 54 | * The options for this lexer. |
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| 55 | * |
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| 56 | * @var array |
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| 57 | */ |
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| 58 | protected $options = []; |
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| 59 | |||
| 60 | /** |
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| 61 | * The previously focused non-ignored token. |
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| 62 | * |
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| 63 | * @var Token |
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| 64 | */ |
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| 65 | protected $lastToken; |
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| 66 | |||
| 67 | /** |
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| 68 | * The currently focused non-ignored token. |
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| 69 | * |
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| 70 | * @var Token |
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| 71 | */ |
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| 72 | protected $token; |
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| 73 | |||
| 74 | /** |
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| 75 | * The current position. |
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| 76 | * |
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| 77 | * @var int |
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| 78 | */ |
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| 79 | protected $pos; |
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| 80 | |||
| 81 | /** |
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| 82 | * The (1-indexed) line containing the current token. |
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| 83 | * |
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| 84 | * @var int |
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| 85 | */ |
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| 86 | protected $line; |
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| 87 | |||
| 88 | /** |
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| 89 | * The character offset at which the current line begins. |
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| 90 | * |
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| 91 | * @var int |
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| 92 | */ |
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| 93 | protected $lineStart; |
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| 94 | |||
| 95 | /** |
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| 96 | * @var array |
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| 97 | */ |
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| 98 | protected static $charCodeCache = []; |
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| 99 | |||
| 100 | /** |
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| 101 | * Lexer constructor. |
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| 102 | * @param Source|null $source |
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| 103 | * @param array $options |
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| 104 | */ |
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| 105 | public function __construct(Source $source, array $options) |
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| 117 | } |
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| 118 | |||
| 119 | /** |
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| 120 | * @inheritdoc |
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| 121 | * @throws SyntaxErrorException |
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| 122 | */ |
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| 123 | public function advance(): Token |
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| 127 | } |
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| 128 | |||
| 129 | /** |
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| 130 | * @inheritdoc |
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| 131 | * @throws SyntaxErrorException |
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| 132 | */ |
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| 133 | public function lookahead(): Token |
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| 134 | { |
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| 135 | $token = $this->token; |
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| 136 | |||
| 137 | if (TokenKindEnum::EOF !== $token->kind) { |
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| 138 | do { |
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| 139 | $next = $token->next = $this->readToken($token); |
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| 140 | $token = $next; |
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| 141 | } while (TokenKindEnum::COMMENT === $token->kind); |
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| 142 | } |
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| 143 | |||
| 144 | return $token; |
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| 145 | } |
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| 146 | |||
| 147 | /** |
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| 148 | * @inheritdoc |
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| 149 | */ |
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| 150 | public function getOption(string $name, $default = null) |
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| 151 | { |
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| 152 | return $this->options[$name] ?? $default; |
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| 153 | } |
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| 154 | |||
| 155 | /** |
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| 156 | * @inheritdoc |
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| 157 | */ |
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| 158 | public function getSource(): Source |
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| 159 | { |
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| 160 | return $this->source; |
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| 161 | } |
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| 162 | |||
| 163 | /** |
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| 164 | * @inheritdoc |
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| 165 | */ |
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| 166 | public function getToken(): Token |
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| 167 | { |
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| 168 | return $this->token; |
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| 169 | } |
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| 170 | |||
| 171 | /** |
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| 172 | * @inheritdoc |
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| 173 | */ |
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| 174 | public function getLastToken(): Token |
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| 175 | { |
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| 176 | return $this->lastToken; |
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| 177 | } |
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| 178 | |||
| 179 | /** |
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| 180 | * @inheritdoc |
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| 181 | */ |
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| 182 | public function createSyntaxErrorException(?string $description = null): SyntaxErrorException |
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| 183 | { |
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| 184 | return new SyntaxErrorException( |
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| 185 | $this->source, |
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| 186 | $this->pos, |
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| 187 | $description ?? $this->unexpectedCharacterMessage($this->readCharCode($this->pos)) |
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| 188 | ); |
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| 189 | } |
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| 190 | |||
| 191 | /** |
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| 192 | * Reads the token after the given token. |
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| 193 | * |
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| 194 | * @param Token $prev |
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| 195 | * @return Token |
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| 196 | * @throws SyntaxErrorException |
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| 197 | */ |
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| 198 | protected function readToken(Token $prev): Token |
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| 199 | { |
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| 200 | $this->pos = $prev->end; |
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| 201 | |||
| 202 | $this->skipWhitespace(); |
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| 203 | |||
| 204 | $line = $this->line; |
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| 205 | $col = (1 + $this->pos) - $this->lineStart; |
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| 206 | |||
| 207 | if ($this->pos >= $this->bodyLength) { |
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| 208 | return $this->createEndOfFileToken($line, $col, $prev); |
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| 209 | } |
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| 210 | |||
| 211 | $code = $this->readCharCode($this->pos); |
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| 212 | |||
| 213 | // Punctuation: [!$&:=@|()\[\]{}]{1} |
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| 214 | if (33 === $code || 36 === $code || 38 === $code || 58 === $code || 61 === $code || 64 === $code || 124 === $code || |
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| 215 | 40 === $code || 41 === $code || 91 === $code || 93 === $code || 123 === $code || 125 === $code) { |
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| 216 | return $this->lexPunctuation($code, $line, $col, $prev); |
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| 217 | } |
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| 218 | |||
| 219 | // Comment: #[\u0009\u0020-\uFFFF]* |
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| 220 | if (35 === $code) { |
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| 221 | return $this->lexComment($line, $col, $prev); |
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| 222 | } |
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| 223 | |||
| 224 | // Int: -?(0|[1-9][0-9]*) |
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| 225 | // Float: -?(0|[1-9][0-9]*)(\.[0-9]+)?((E|e)(+|-)?[0-9]+)? |
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| 226 | if (45 === $code || isNumber($code)) { |
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| 227 | return $this->lexNumber($code, $line, $col, $prev); |
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| 228 | } |
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| 229 | |||
| 230 | // Name: [_A-Za-z][_0-9A-Za-z]* |
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| 231 | if (isAlphaNumeric($code)) { |
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| 232 | return $this->lexName($line, $col, $prev); |
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| 233 | } |
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| 234 | |||
| 235 | // Spread: ... |
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| 236 | if ($this->bodyLength >= 3 && $this->isSpread($code)) { |
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| 237 | return $this->lexSpread($line, $col, $prev); |
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| 238 | } |
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| 239 | |||
| 240 | // String: "([^"\\\u000A\u000D]|(\\(u[0-9a-fA-F]{4}|["\\/bfnrt])))*" |
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| 241 | if ($this->isString($code)) { |
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| 242 | return $this->lexString($line, $col, $prev); |
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| 243 | } |
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| 244 | |||
| 245 | // Block String: """("?"?(\\"""|\\(?!=""")|[^"\\]))*""" |
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| 246 | if ($this->bodyLength >= 3 && $this->isTripleQuote($code)) { |
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| 247 | return $this->lexBlockString($line, $col, $prev); |
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| 248 | } |
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| 249 | |||
| 250 | throw $this->createSyntaxErrorException(); |
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| 251 | } |
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| 252 | |||
| 253 | /** |
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| 254 | * @return Token |
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| 255 | */ |
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| 256 | protected function createStartOfFileToken(): Token |
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| 259 | } |
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| 260 | |||
| 261 | /** |
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| 262 | * Creates an End Of File (EOF) token. |
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| 263 | * |
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| 264 | * @param int $line |
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| 265 | * @param int $col |
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| 266 | * @param Token $prev |
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| 267 | * @return Token |
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| 268 | */ |
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| 269 | protected function createEndOfFileToken(int $line, int $col, Token $prev): Token |
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| 270 | { |
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| 271 | return new Token(TokenKindEnum::EOF, $this->bodyLength, $this->bodyLength, $line, $col, $prev); |
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| 272 | } |
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| 273 | |||
| 274 | /** |
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| 275 | * Reads a punctuation token from the source file. |
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| 276 | * |
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| 277 | * @param int $code |
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| 278 | * @param int $line |
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| 279 | * @param int $col |
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| 280 | * @param Token $prev |
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| 281 | * @return Token |
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| 282 | * @throws SyntaxErrorException |
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| 283 | */ |
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| 284 | protected function lexPunctuation(int $code, int $line, int $col, Token $prev): ?Token |
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| 285 | { |
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| 286 | if (!isset(self::$codeTokenKindMap[$code])) { |
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| 287 | throw $this->createSyntaxErrorException(); |
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| 288 | } |
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| 289 | |||
| 290 | return new Token(self::$codeTokenKindMap[$code], $this->pos, $this->pos + 1, $line, $col, $prev); |
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| 291 | } |
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| 292 | |||
| 293 | /** |
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| 294 | * Reads a name token from the source file. |
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| 295 | * |
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| 296 | * @param int $line |
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| 297 | * @param int $col |
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| 298 | * @param Token $prev |
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| 299 | * @return Token |
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| 300 | */ |
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| 301 | protected function lexName(int $line, int $col, Token $prev): Token |
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| 302 | { |
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| 303 | $start = $this->pos; |
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| 304 | |||
| 305 | ++$this->pos; |
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| 306 | |||
| 307 | while ($this->pos !== $this->bodyLength && |
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| 308 | ($code = $this->readCharCode($this->pos)) !== null && |
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| 309 | isAlphaNumeric($code)) { |
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| 310 | ++$this->pos; |
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| 311 | } |
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| 312 | |||
| 313 | $value = sliceString($this->body, $start, $this->pos); |
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| 314 | |||
| 315 | return new Token(TokenKindEnum::NAME, $start, $this->pos, $line, $col, $prev, $value); |
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| 316 | } |
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| 317 | |||
| 318 | /** |
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| 319 | * Reads a number (int or float) token from the source file. |
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| 320 | * |
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| 321 | * @param int $code |
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| 322 | * @param int $line |
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| 323 | * @param int $col |
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| 324 | * @param Token $prev |
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| 325 | * @return Token |
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| 326 | * @throws SyntaxErrorException |
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| 327 | */ |
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| 328 | protected function lexNumber(int $code, int $line, int $col, Token $prev): Token |
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| 383 | ); |
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| 384 | } |
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| 385 | |||
| 386 | /** |
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| 387 | * Skips digits at the current position. |
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| 388 | * |
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| 389 | * @param int $code |
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| 390 | * @throws SyntaxErrorException |
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| 391 | */ |
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| 392 | protected function skipDigits(int $code): void |
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| 393 | { |
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| 394 | if (isNumber($code)) { |
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| 395 | do { |
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| 396 | $code = $this->readCharCode(++$this->pos); |
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| 397 | } while (isNumber($code)); |
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| 398 | |||
| 399 | return; |
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| 400 | } |
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| 401 | |||
| 402 | throw $this->createSyntaxErrorException( |
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| 403 | \sprintf('Invalid number, expected digit but got: %s.', printCharCode($code)) |
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| 404 | ); |
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| 405 | } |
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| 406 | |||
| 407 | /** |
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| 408 | * Reads a comment token from the source file. |
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| 409 | * |
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| 410 | * @param int $line |
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| 411 | * @param int $col |
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| 412 | * @param Token $prev |
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| 413 | * @return Token |
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| 414 | */ |
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| 415 | protected function lexComment(int $line, int $col, Token $prev): Token |
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| 416 | { |
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| 417 | $start = $this->pos; |
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| 418 | |||
| 419 | do { |
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| 420 | $code = $this->readCharCode(++$this->pos); |
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| 421 | } while ($code !== null && ($code > 0x001f || 0x0009 === $code)); // SourceCharacter but not LineTerminator |
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| 422 | |||
| 423 | return new Token( |
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| 424 | TokenKindEnum::COMMENT, |
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| 425 | $start, |
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| 426 | $this->pos, |
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| 427 | $line, |
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| 428 | $col, |
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| 429 | $prev, |
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| 430 | sliceString($this->body, $start + 1, $this->pos) |
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| 431 | ); |
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| 432 | } |
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| 433 | |||
| 434 | /** |
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| 435 | * Reads a spread token from the source. |
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| 436 | * |
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| 437 | * @param int $line |
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| 438 | * @param int $col |
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| 439 | * @param Token $prev |
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| 440 | * @return Token |
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| 441 | */ |
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| 442 | protected function lexSpread(int $line, int $col, Token $prev): Token |
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| 443 | { |
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| 444 | return new Token(TokenKindEnum::SPREAD, $this->pos, $this->pos + 3, $line, $col, $prev); |
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| 445 | } |
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| 446 | |||
| 447 | /** |
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| 448 | * Reads a string token from the source. |
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| 449 | * |
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| 450 | * @param int $line |
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| 451 | * @param int $col |
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| 452 | * @param Token $prev |
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| 453 | * @return Token |
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| 454 | * @throws SyntaxErrorException |
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| 455 | */ |
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| 456 | protected function lexString(int $line, int $col, Token $prev): Token |
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| 457 | { |
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| 458 | $start = $this->pos; |
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| 459 | $chunkStart = ++$this->pos; // skip the quote |
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| 460 | $value = ''; |
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| 461 | |||
| 462 | while ($this->pos < $this->bodyLength && |
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| 463 | ($code = $this->readCharCode($this->pos)) !== null && !isLineTerminator($code)) { |
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| 464 | // Closing Quote (") |
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| 465 | if (34 === $code) { |
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| 466 | $value .= sliceString($this->body, $chunkStart, $this->pos); |
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| 467 | return new Token(TokenKindEnum::STRING, $start, $this->pos + 1, $line, $col, $prev, $value); |
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| 468 | } |
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| 469 | |||
| 470 | if (isSourceCharacter($code)) { |
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| 471 | throw $this->createSyntaxErrorException( |
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| 472 | \sprintf('Invalid character within String: %s.', printCharCode($code)) |
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| 473 | ); |
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| 474 | } |
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| 475 | |||
| 476 | ++$this->pos; |
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| 477 | |||
| 478 | if (92 === $code) { |
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| 479 | // \ |
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| 480 | $value .= sliceString($this->body, $chunkStart, $this->pos - 1); |
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| 481 | |||
| 482 | $code = $this->readCharCode($this->pos); |
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| 483 | |||
| 484 | switch ($code) { |
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| 485 | case 34: // " |
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| 486 | $value .= '"'; |
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| 487 | break; |
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| 488 | case 47: // / |
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| 489 | $value .= '/'; |
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| 490 | break; |
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| 491 | case 92: // \ |
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| 492 | $value .= '\\'; |
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| 493 | break; |
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| 494 | case 98: // b |
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| 495 | $value .= '\b'; |
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| 496 | break; |
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| 497 | case 102: // f |
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| 498 | $value .= '\f'; |
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| 499 | break; |
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| 500 | case 110: // n |
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| 501 | $value .= '\n'; |
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| 502 | break; |
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| 503 | case 114: // r |
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| 504 | $value .= '\r'; |
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| 505 | break; |
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| 506 | case 116: // t |
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| 507 | $value .= '\t'; |
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| 508 | break; |
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| 509 | case 117: // u |
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| 510 | $unicodeString = sliceString($this->body, $this->pos + 1, $this->pos + 5); |
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| 511 | |||
| 512 | if (!\preg_match('/[0-9A-Fa-f]{4}/', $unicodeString)) { |
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| 513 | throw $this->createSyntaxErrorException( |
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| 514 | \sprintf('Invalid character escape sequence: \\u%s.', $unicodeString) |
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| 515 | ); |
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| 516 | } |
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| 517 | |||
| 518 | $value .= '\\u' . $unicodeString; |
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| 519 | $this->pos += 4; |
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| 520 | |||
| 521 | break; |
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| 522 | default: |
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| 523 | throw $this->createSyntaxErrorException( |
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| 524 | \sprintf('Invalid character escape sequence: \\%s.', \chr($code)) |
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| 525 | ); |
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| 526 | } |
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| 527 | |||
| 528 | ++$this->pos; |
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| 529 | |||
| 530 | $chunkStart = $this->pos; |
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| 531 | } |
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| 532 | } |
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| 533 | |||
| 534 | throw $this->createSyntaxErrorException('Unterminated string.'); |
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| 535 | } |
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| 536 | |||
| 537 | /** |
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| 538 | * Reads a block string token from the source file. |
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| 539 | * |
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| 540 | * @param int $line |
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| 541 | * @param int $col |
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| 542 | * @param Token $prev |
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| 543 | * @return Token |
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| 544 | * @throws SyntaxErrorException |
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| 545 | */ |
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| 546 | protected function lexBlockString(int $line, int $col, Token $prev): Token |
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| 584 | } |
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| 585 | |||
| 586 | /** |
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| 587 | * Skips whitespace at the current position. |
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| 588 | */ |
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| 589 | protected function skipWhitespace(): void |
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| 614 | } |
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| 615 | } |
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| 616 | } |
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| 617 | |||
| 618 | /** |
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| 619 | * @param int $pos |
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| 620 | * @return int |
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| 621 | */ |
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| 622 | protected function readCharCode(int $pos): int |
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| 623 | { |
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| 624 | $char = \mb_substr($this->body, $pos, 1, self::ENCODING); |
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| 641 | } |
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| 642 | |||
| 643 | /** |
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| 644 | * Report a message that an unexpected character was encountered. |
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| 645 | * |
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| 646 | * @param int $code |
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| 647 | * @return string |
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| 648 | */ |
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| 649 | protected function unexpectedCharacterMessage(int $code): string |
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| 650 | { |
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| 651 | if (isSourceCharacter($code) && !isLineTerminator($code)) { |
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| 652 | return \sprintf('Cannot contain the invalid character %s.', printCharCode($code)); |
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| 653 | } |
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| 654 | |||
| 655 | if ($code === 39) { |
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| 656 | // ' |
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| 657 | return 'Unexpected single quote character (\'), did you mean to use a double quote (")?'; |
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| 658 | } |
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| 659 | |||
| 660 | return \sprintf('Cannot parse the unexpected character %s.', printCharCode($code)); |
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| 661 | } |
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| 662 | |||
| 663 | /** |
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| 664 | * @param int $code |
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| 665 | * @return bool |
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| 666 | */ |
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| 667 | protected function isSpread(int $code): bool |
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| 668 | { |
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| 669 | return 46 === $code && |
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| 670 | $this->readCharCode($this->pos + 1) === 46 && |
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| 671 | $this->readCharCode($this->pos + 2) === 46; // ... |
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| 672 | } |
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| 673 | |||
| 674 | /** |
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| 675 | * @param int $code |
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| 676 | * @return bool |
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| 677 | */ |
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| 678 | protected function isString(int $code): bool |
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| 679 | { |
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| 680 | return 34 === $code && $this->readCharCode($this->pos + 1) !== 34; |
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| 681 | } |
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| 682 | |||
| 683 | /** |
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| 684 | * @param int $code |
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| 685 | * @return bool |
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| 686 | */ |
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| 687 | protected function isTripleQuote(int $code): bool |
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| 688 | { |
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| 689 | return 34 === $code && |
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| 690 | 34 === $this->readCharCode($this->pos + 1) && |
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| 691 | 34 === $this->readCharCode($this->pos + 2); // """ |
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| 692 | } |
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| 693 | |||
| 694 | /** |
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| 695 | * @param int $code |
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| 696 | * @return bool |
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| 697 | */ |
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| 698 | protected function isEscapedTripleQuote(int $code): bool |
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| 704 | } |
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| 705 | } |
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| 706 |
