Duplicate code is one of the most pungent code smells. A rule that is often used is to re-structure code once it is duplicated in three or more places.
Common duplication problems, and corresponding solutions are:
Complex classes like Json5Decoder 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. You can also have a look at the cohesion graph to spot any un-connected, or weakly-connected components.
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 Json5Decoder, and based on these observations, apply Extract Interface, too.
| 1 | <?php |
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| 17 | final class Json5Decoder |
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| 18 | { |
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| 19 | private $json; |
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| 20 | |||
| 21 | private $length; |
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| 22 | |||
| 23 | private $at = 0; |
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| 24 | |||
| 25 | private $currentByte; |
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| 26 | |||
| 27 | private $lineNumber = 1; |
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| 28 | |||
| 29 | private $associative = false; |
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| 30 | |||
| 31 | private $maxDepth = 512; |
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| 32 | |||
| 33 | private $castBigIntToString = false; |
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| 34 | |||
| 35 | private $depth = 1; |
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| 36 | |||
| 37 | private $currentLineStartsAt = 0; |
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| 38 | |||
| 39 | /** |
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| 40 | * Private constructor. |
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| 41 | * |
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| 42 | * @param string $json |
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| 43 | * @param bool $associative |
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| 44 | * @param int $depth |
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| 45 | * @param bool $castBigIntToString |
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| 46 | */ |
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| 47 | 376 | private function __construct($json, $associative = false, $depth = 512, $castBigIntToString = false) |
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| 48 | { |
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| 49 | 376 | $this->json = $json; |
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| 50 | 376 | $this->associative = $associative; |
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| 51 | 376 | $this->maxDepth = $depth; |
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| 52 | 376 | $this->castBigIntToString = $castBigIntToString; |
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| 53 | |||
| 54 | 376 | $this->length = strlen($json); |
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| 55 | 376 | $this->currentByte = $this->getByte(0); |
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| 56 | 376 | } |
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| 57 | |||
| 58 | /** |
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| 59 | * Takes a JSON encoded string and converts it into a PHP variable. |
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| 60 | * |
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| 61 | * The parameters exactly match PHP's json_decode() function - see |
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| 62 | * http://php.net/manual/en/function.json-decode.php for more information. |
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| 63 | * |
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| 64 | * @param string $source The JSON string being decoded. |
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| 65 | * @param bool $associative When TRUE, returned objects will be converted into associative arrays. |
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| 66 | * @param int $depth User specified recursion depth. |
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| 67 | * @param int $options Bitmask of JSON decode options. |
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| 68 | * |
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| 69 | * @return mixed |
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| 70 | */ |
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| 71 | 411 | public static function decode($source, $associative = false, $depth = 512, $options = 0) |
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| 72 | { |
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| 73 | // Try parsing with json_decode first, since that's much faster |
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| 74 | // We only attempt this on PHP 7+ because 5.x doesn't parse some edge cases correctly |
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| 75 | 411 | if (PHP_VERSION_ID >= 70000) { |
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| 76 | 137 | $result = json_decode($source, $associative, $depth, $options); |
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| 77 | 137 | if (json_last_error() === JSON_ERROR_NONE) { |
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| 78 | 35 | return $result; |
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| 79 | } |
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| 80 | } |
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| 81 | |||
| 82 | // Fall back to JSON5 if that fails |
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| 83 | 376 | $associative = $associative === true || ($associative === null && $options & JSON_OBJECT_AS_ARRAY); |
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| 84 | 376 | $castBigIntToString = $options & JSON_BIGINT_AS_STRING; |
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| 85 | |||
| 86 | 376 | $decoder = new self((string)$source, $associative, $depth, $castBigIntToString); |
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| 87 | |||
| 88 | 376 | $result = $decoder->value(); |
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| 89 | 277 | $decoder->white(); |
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| 90 | 274 | if ($decoder->currentByte) { |
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| 91 | 18 | $decoder->throwSyntaxError('Syntax error'); |
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| 92 | } |
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| 93 | |||
| 94 | 256 | return $result; |
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| 95 | } |
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| 96 | |||
| 97 | /** |
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| 98 | * @param int $at |
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| 99 | * |
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| 100 | * @return null |
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| 101 | */ |
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| 102 | 376 | private function getByte($at) |
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| 103 | { |
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| 104 | 376 | if ($at >= $this->length) { |
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| 105 | 271 | return null; |
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| 106 | } |
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| 107 | |||
| 108 | 373 | return $this->json[$at]; |
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| 109 | } |
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| 110 | |||
| 111 | /** |
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| 112 | * @return string|null |
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| 113 | */ |
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| 114 | 33 | private function currentChar() |
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| 115 | { |
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| 116 | 33 | if ($this->at >= $this->length) { |
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| 117 | 12 | return null; |
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| 118 | } |
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| 119 | |||
| 120 | 21 | return mb_substr(substr($this->json, $this->at, 4), 0, 1); |
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| 121 | } |
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| 122 | |||
| 123 | /** |
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| 124 | * Parse the next character. |
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| 125 | * |
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| 126 | * @return null|string |
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| 127 | */ |
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| 128 | 348 | private function next() |
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| 129 | { |
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| 130 | // Get the next character. When there are no more characters, |
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| 131 | // return the empty string. |
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| 132 | 348 | if ($this->currentByte === "\n" || ($this->currentByte === "\r" && $this->peek() !== "\n")) { |
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| 133 | 258 | $this->lineNumber++; |
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| 134 | 258 | $this->currentLineStartsAt = $this->at + 1; |
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| 135 | 188 | } |
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| 136 | |||
| 137 | 348 | $this->at++; |
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| 138 | |||
| 139 | 348 | return $this->currentByte = $this->getByte($this->at); |
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| 140 | } |
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| 141 | |||
| 142 | /** |
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| 143 | * Parse the next character if it matches $c or fail. |
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| 144 | * |
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| 145 | * @param string $c |
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| 146 | * |
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| 147 | * @return string|null |
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| 148 | */ |
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| 149 | 167 | private function nextOrFail($c) |
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| 150 | { |
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| 151 | 167 | if ($c !== $this->currentByte) { |
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| 152 | 24 | $this->throwSyntaxError(sprintf( |
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| 153 | 24 | 'Expected %s instead of %s', |
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| 154 | 24 | self::renderChar($c), |
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| 155 | 24 | self::renderChar($this->currentChar()) |
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| 156 | 16 | )); |
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| 157 | } |
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| 158 | |||
| 159 | 167 | return $this->next(); |
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| 160 | } |
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| 161 | |||
| 162 | /** |
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| 163 | * Get the next character without consuming it or |
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| 164 | * assigning it to the ch variable. |
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| 165 | * |
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| 166 | * @return mixed |
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| 167 | */ |
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| 168 | 37 | private function peek() |
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| 172 | |||
| 173 | /** |
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| 174 | * Attempt to match a regular expression at the current position on the current line. |
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| 175 | * |
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| 176 | * This function will not match across multiple lines. |
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| 177 | * |
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| 178 | * @param string $regex |
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| 179 | * |
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| 180 | * @return string|null |
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| 181 | */ |
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| 182 | 195 | private function match($regex) |
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| 199 | |||
| 200 | /** |
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| 201 | * Parse an identifier. |
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| 202 | * |
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| 203 | * Normally, reserved words are disallowed here, but we |
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| 204 | * only use this for unquoted object keys, where reserved words are allowed, |
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| 205 | * so we don't check for those here. References: |
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| 206 | * - http://es5.github.com/#x7.6 |
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| 207 | * - https://developer.mozilla.org/en/Core_JavaScript_1.5_Guide/Core_Language_Features#Variables |
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| 208 | * - http://docstore.mik.ua/orelly/webprog/jscript/ch02_07.htm |
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| 209 | */ |
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| 210 | 42 | private function identifier() |
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| 228 | |||
| 229 | 200 | private function number() |
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| 304 | |||
| 305 | 83 | private function string() |
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| 348 | |||
| 349 | /** |
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| 350 | * Skip an inline comment, assuming this is one. |
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| 351 | * |
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| 352 | * The current character should be the second / character in the // pair that begins this inline comment. |
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| 353 | * To finish the inline comment, we look for a newline or the end of the text. |
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| 354 | */ |
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| 355 | 36 | private function inlineComment() |
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| 366 | |||
| 367 | /** |
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| 368 | * Skip a block comment, assuming this is one. |
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| 369 | * |
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| 370 | * The current character should be the * character in the /* pair that begins this block comment. |
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| 371 | * To finish the block comment, we look for an ending */ pair of characters, |
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| 372 | * but we also watch for the end of text before the comment is terminated. |
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| 373 | */ |
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| 374 | 21 | private function blockComment() |
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| 390 | |||
| 391 | /** |
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| 392 | * Skip a comment, whether inline or block-level, assuming this is one. |
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| 393 | */ |
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| 394 | 57 | private function comment() |
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| 407 | |||
| 408 | /** |
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| 409 | * Skip whitespace and comments. |
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| 410 | * |
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| 411 | * Note that we're detecting comments by only a single / character. |
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| 412 | * This works since regular expressions are not valid JSON(5), but this will |
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| 413 | * break if there are other valid values that begin with a / character! |
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| 414 | */ |
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| 415 | 376 | private function white() |
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| 431 | |||
| 432 | /** |
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| 433 | * Matches true, false, null, etc |
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| 434 | */ |
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| 435 | 88 | private function word() |
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| 476 | |||
| 477 | 37 | private function arr() |
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| 513 | |||
| 514 | /** |
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| 515 | * Parse an object value |
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| 516 | */ |
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| 517 | 84 | private function obj() |
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| 561 | |||
| 562 | /** |
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| 563 | * Parse a JSON value. |
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| 564 | * |
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| 565 | * It could be an object, an array, a string, a number, |
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| 566 | * or a word. |
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| 567 | */ |
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| 568 | 376 | private function value() |
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| 587 | |||
| 588 | 120 | private function throwSyntaxError($message) |
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| 596 | |||
| 597 | 33 | private static function renderChar($chr) |
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| 601 | |||
| 602 | /** |
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| 603 | * @param string $ch |
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| 604 | * |
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| 605 | * @return string|null |
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| 606 | */ |
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| 607 | 18 | private static function getEscapee($ch) |
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| 625 | } |
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| 626 |
It seems like the type of the argument is not accepted by the function/method which you are calling.
In some cases, in particular if PHP’s automatic type-juggling kicks in this might be fine. In other cases, however this might be a bug.
We suggest to add an explicit type cast like in the following example: