1<?php
2
3/*
4 * This file is part of the Symfony package.
5 *
6 * (c) Fabien Potencier <fabien@symfony.com>
7 *
8 * For the full copyright and license information, please view the LICENSE
9 * file that was distributed with this source code.
10 */
11
12namespace Symfony\Component\Yaml;
13
14use Symfony\Component\Yaml\Exception\DumpException;
15use Symfony\Component\Yaml\Exception\ParseException;
16use Symfony\Component\Yaml\Tag\TaggedValue;
17
18/**
19 * Inline implements a YAML parser/dumper for the YAML inline syntax.
20 *
21 * @author Fabien Potencier <fabien@symfony.com>
22 *
23 * @internal
24 */
25class Inline
26{
27    const REGEX_QUOTED_STRING = '(?:"([^"\\\\]*+(?:\\\\.[^"\\\\]*+)*+)"|\'([^\']*+(?:\'\'[^\']*+)*+)\')';
28
29    public static $parsedLineNumber = -1;
30    public static $parsedFilename;
31
32    private static $exceptionOnInvalidType = false;
33    private static $objectSupport = false;
34    private static $objectForMap = false;
35    private static $constantSupport = false;
36
37    /**
38     * @param int         $flags
39     * @param int|null    $parsedLineNumber
40     * @param string|null $parsedFilename
41     */
42    public static function initialize($flags, $parsedLineNumber = null, $parsedFilename = null)
43    {
44        self::$exceptionOnInvalidType = (bool) (Yaml::PARSE_EXCEPTION_ON_INVALID_TYPE & $flags);
45        self::$objectSupport = (bool) (Yaml::PARSE_OBJECT & $flags);
46        self::$objectForMap = (bool) (Yaml::PARSE_OBJECT_FOR_MAP & $flags);
47        self::$constantSupport = (bool) (Yaml::PARSE_CONSTANT & $flags);
48        self::$parsedFilename = $parsedFilename;
49
50        if (null !== $parsedLineNumber) {
51            self::$parsedLineNumber = $parsedLineNumber;
52        }
53    }
54
55    /**
56     * Converts a YAML string to a PHP value.
57     *
58     * @param string $value      A YAML string
59     * @param int    $flags      A bit field of PARSE_* constants to customize the YAML parser behavior
60     * @param array  $references Mapping of variable names to values
61     *
62     * @return mixed A PHP value
63     *
64     * @throws ParseException
65     */
66    public static function parse(string $value = null, int $flags = 0, array $references = [])
67    {
68        self::initialize($flags);
69
70        $value = trim($value);
71
72        if ('' === $value) {
73            return '';
74        }
75
76        if (2 /* MB_OVERLOAD_STRING */ & (int) ini_get('mbstring.func_overload')) {
77            $mbEncoding = mb_internal_encoding();
78            mb_internal_encoding('ASCII');
79        }
80
81        try {
82            $i = 0;
83            $tag = self::parseTag($value, $i, $flags);
84            switch ($value[$i]) {
85                case '[':
86                    $result = self::parseSequence($value, $flags, $i, $references);
87                    ++$i;
88                    break;
89                case '{':
90                    $result = self::parseMapping($value, $flags, $i, $references);
91                    ++$i;
92                    break;
93                default:
94                    $result = self::parseScalar($value, $flags, null, $i, null === $tag, $references);
95            }
96
97            if (null !== $tag && '' !== $tag) {
98                return new TaggedValue($tag, $result);
99            }
100
101            // some comments are allowed at the end
102            if (preg_replace('/\s+#.*$/A', '', substr($value, $i))) {
103                throw new ParseException(sprintf('Unexpected characters near "%s".', substr($value, $i)), self::$parsedLineNumber + 1, $value, self::$parsedFilename);
104            }
105
106            return $result;
107        } finally {
108            if (isset($mbEncoding)) {
109                mb_internal_encoding($mbEncoding);
110            }
111        }
112    }
113
114    /**
115     * Dumps a given PHP variable to a YAML string.
116     *
117     * @param mixed $value The PHP variable to convert
118     * @param int   $flags A bit field of Yaml::DUMP_* constants to customize the dumped YAML string
119     *
120     * @return string The YAML string representing the PHP value
121     *
122     * @throws DumpException When trying to dump PHP resource
123     */
124    public static function dump($value, int $flags = 0): string
125    {
126        switch (true) {
127            case \is_resource($value):
128                if (Yaml::DUMP_EXCEPTION_ON_INVALID_TYPE & $flags) {
129                    throw new DumpException(sprintf('Unable to dump PHP resources in a YAML file ("%s").', get_resource_type($value)));
130                }
131
132                return 'null';
133            case $value instanceof \DateTimeInterface:
134                return $value->format('c');
135            case \is_object($value):
136                if ($value instanceof TaggedValue) {
137                    return '!'.$value->getTag().' '.self::dump($value->getValue(), $flags);
138                }
139
140                if (Yaml::DUMP_OBJECT & $flags) {
141                    return '!php/object '.self::dump(serialize($value));
142                }
143
144                if (Yaml::DUMP_OBJECT_AS_MAP & $flags && ($value instanceof \stdClass || $value instanceof \ArrayObject)) {
145                    $output = [];
146
147                    foreach ($value as $key => $val) {
148                        $output[] = sprintf('%s: %s', self::dump($key, $flags), self::dump($val, $flags));
149                    }
150
151                    return sprintf('{ %s }', implode(', ', $output));
152                }
153
154                if (Yaml::DUMP_EXCEPTION_ON_INVALID_TYPE & $flags) {
155                    throw new DumpException('Object support when dumping a YAML file has been disabled.');
156                }
157
158                return 'null';
159            case \is_array($value):
160                return self::dumpArray($value, $flags);
161            case null === $value:
162                return 'null';
163            case true === $value:
164                return 'true';
165            case false === $value:
166                return 'false';
167            case ctype_digit($value):
168                return \is_string($value) ? "'$value'" : (int) $value;
169            case is_numeric($value):
170                $locale = setlocale(LC_NUMERIC, 0);
171                if (false !== $locale) {
172                    setlocale(LC_NUMERIC, 'C');
173                }
174                if (\is_float($value)) {
175                    $repr = (string) $value;
176                    if (is_infinite($value)) {
177                        $repr = str_ireplace('INF', '.Inf', $repr);
178                    } elseif (floor($value) == $value && $repr == $value) {
179                        // Preserve float data type since storing a whole number will result in integer value.
180                        $repr = '!!float '.$repr;
181                    }
182                } else {
183                    $repr = \is_string($value) ? "'$value'" : (string) $value;
184                }
185                if (false !== $locale) {
186                    setlocale(LC_NUMERIC, $locale);
187                }
188
189                return $repr;
190            case '' == $value:
191                return "''";
192            case self::isBinaryString($value):
193                return '!!binary '.base64_encode($value);
194            case Escaper::requiresDoubleQuoting($value):
195                return Escaper::escapeWithDoubleQuotes($value);
196            case Escaper::requiresSingleQuoting($value):
197            case Parser::preg_match('{^[0-9]+[_0-9]*$}', $value):
198            case Parser::preg_match(self::getHexRegex(), $value):
199            case Parser::preg_match(self::getTimestampRegex(), $value):
200                return Escaper::escapeWithSingleQuotes($value);
201            default:
202                return $value;
203        }
204    }
205
206    /**
207     * Check if given array is hash or just normal indexed array.
208     *
209     * @param array|\ArrayObject|\stdClass $value The PHP array or array-like object to check
210     *
211     * @return bool true if value is hash array, false otherwise
212     */
213    public static function isHash($value): bool
214    {
215        if ($value instanceof \stdClass || $value instanceof \ArrayObject) {
216            return true;
217        }
218
219        $expectedKey = 0;
220
221        foreach ($value as $key => $val) {
222            if ($key !== $expectedKey++) {
223                return true;
224            }
225        }
226
227        return false;
228    }
229
230    /**
231     * Dumps a PHP array to a YAML string.
232     *
233     * @param array $value The PHP array to dump
234     * @param int   $flags A bit field of Yaml::DUMP_* constants to customize the dumped YAML string
235     *
236     * @return string The YAML string representing the PHP array
237     */
238    private static function dumpArray(array $value, int $flags): string
239    {
240        // array
241        if (($value || Yaml::DUMP_EMPTY_ARRAY_AS_SEQUENCE & $flags) && !self::isHash($value)) {
242            $output = [];
243            foreach ($value as $val) {
244                $output[] = self::dump($val, $flags);
245            }
246
247            return sprintf('[%s]', implode(', ', $output));
248        }
249
250        // hash
251        $output = [];
252        foreach ($value as $key => $val) {
253            $output[] = sprintf('%s: %s', self::dump($key, $flags), self::dump($val, $flags));
254        }
255
256        return sprintf('{ %s }', implode(', ', $output));
257    }
258
259    /**
260     * Parses a YAML scalar.
261     *
262     * @return mixed
263     *
264     * @throws ParseException When malformed inline YAML string is parsed
265     */
266    public static function parseScalar(string $scalar, int $flags = 0, array $delimiters = null, int &$i = 0, bool $evaluate = true, array $references = [])
267    {
268        if (\in_array($scalar[$i], ['"', "'"])) {
269            // quoted scalar
270            $output = self::parseQuotedScalar($scalar, $i);
271
272            if (null !== $delimiters) {
273                $tmp = ltrim(substr($scalar, $i), ' ');
274                if ('' === $tmp) {
275                    throw new ParseException(sprintf('Unexpected end of line, expected one of "%s".', implode('', $delimiters)), self::$parsedLineNumber + 1, $scalar, self::$parsedFilename);
276                }
277                if (!\in_array($tmp[0], $delimiters)) {
278                    throw new ParseException(sprintf('Unexpected characters (%s).', substr($scalar, $i)), self::$parsedLineNumber + 1, $scalar, self::$parsedFilename);
279                }
280            }
281        } else {
282            // "normal" string
283            if (!$delimiters) {
284                $output = substr($scalar, $i);
285                $i += \strlen($output);
286
287                // remove comments
288                if (Parser::preg_match('/[ \t]+#/', $output, $match, PREG_OFFSET_CAPTURE)) {
289                    $output = substr($output, 0, $match[0][1]);
290                }
291            } elseif (Parser::preg_match('/^(.*?)('.implode('|', $delimiters).')/', substr($scalar, $i), $match)) {
292                $output = $match[1];
293                $i += \strlen($output);
294                $output = trim($output);
295            } else {
296                throw new ParseException(sprintf('Malformed inline YAML string: %s.', $scalar), self::$parsedLineNumber + 1, null, self::$parsedFilename);
297            }
298
299            // a non-quoted string cannot start with @ or ` (reserved) nor with a scalar indicator (| or >)
300            if ($output && ('@' === $output[0] || '`' === $output[0] || '|' === $output[0] || '>' === $output[0] || '%' === $output[0])) {
301                throw new ParseException(sprintf('The reserved indicator "%s" cannot start a plain scalar; you need to quote the scalar.', $output[0]), self::$parsedLineNumber + 1, $output, self::$parsedFilename);
302            }
303
304            if ($evaluate) {
305                $output = self::evaluateScalar($output, $flags, $references);
306            }
307        }
308
309        return $output;
310    }
311
312    /**
313     * Parses a YAML quoted scalar.
314     *
315     * @throws ParseException When malformed inline YAML string is parsed
316     */
317    private static function parseQuotedScalar(string $scalar, int &$i): string
318    {
319        if (!Parser::preg_match('/'.self::REGEX_QUOTED_STRING.'/Au', substr($scalar, $i), $match)) {
320            throw new ParseException(sprintf('Malformed inline YAML string: %s.', substr($scalar, $i)), self::$parsedLineNumber + 1, $scalar, self::$parsedFilename);
321        }
322
323        $output = substr($match[0], 1, \strlen($match[0]) - 2);
324
325        $unescaper = new Unescaper();
326        if ('"' == $scalar[$i]) {
327            $output = $unescaper->unescapeDoubleQuotedString($output);
328        } else {
329            $output = $unescaper->unescapeSingleQuotedString($output);
330        }
331
332        $i += \strlen($match[0]);
333
334        return $output;
335    }
336
337    /**
338     * Parses a YAML sequence.
339     *
340     * @throws ParseException When malformed inline YAML string is parsed
341     */
342    private static function parseSequence(string $sequence, int $flags, int &$i = 0, array $references = []): array
343    {
344        $output = [];
345        $len = \strlen($sequence);
346        ++$i;
347
348        // [foo, bar, ...]
349        while ($i < $len) {
350            if (']' === $sequence[$i]) {
351                return $output;
352            }
353            if (',' === $sequence[$i] || ' ' === $sequence[$i]) {
354                ++$i;
355
356                continue;
357            }
358
359            $tag = self::parseTag($sequence, $i, $flags);
360            switch ($sequence[$i]) {
361                case '[':
362                    // nested sequence
363                    $value = self::parseSequence($sequence, $flags, $i, $references);
364                    break;
365                case '{':
366                    // nested mapping
367                    $value = self::parseMapping($sequence, $flags, $i, $references);
368                    break;
369                default:
370                    $isQuoted = \in_array($sequence[$i], ['"', "'"]);
371                    $value = self::parseScalar($sequence, $flags, [',', ']'], $i, null === $tag, $references);
372
373                    // the value can be an array if a reference has been resolved to an array var
374                    if (\is_string($value) && !$isQuoted && false !== strpos($value, ': ')) {
375                        // embedded mapping?
376                        try {
377                            $pos = 0;
378                            $value = self::parseMapping('{'.$value.'}', $flags, $pos, $references);
379                        } catch (\InvalidArgumentException $e) {
380                            // no, it's not
381                        }
382                    }
383
384                    --$i;
385            }
386
387            if (null !== $tag && '' !== $tag) {
388                $value = new TaggedValue($tag, $value);
389            }
390
391            $output[] = $value;
392
393            ++$i;
394        }
395
396        throw new ParseException(sprintf('Malformed inline YAML string: %s.', $sequence), self::$parsedLineNumber + 1, null, self::$parsedFilename);
397    }
398
399    /**
400     * Parses a YAML mapping.
401     *
402     * @return array|\stdClass
403     *
404     * @throws ParseException When malformed inline YAML string is parsed
405     */
406    private static function parseMapping(string $mapping, int $flags, int &$i = 0, array $references = [])
407    {
408        $output = [];
409        $len = \strlen($mapping);
410        ++$i;
411        $allowOverwrite = false;
412
413        // {foo: bar, bar:foo, ...}
414        while ($i < $len) {
415            switch ($mapping[$i]) {
416                case ' ':
417                case ',':
418                    ++$i;
419                    continue 2;
420                case '}':
421                    if (self::$objectForMap) {
422                        return (object) $output;
423                    }
424
425                    return $output;
426            }
427
428            // key
429            $offsetBeforeKeyParsing = $i;
430            $isKeyQuoted = \in_array($mapping[$i], ['"', "'"], true);
431            $key = self::parseScalar($mapping, $flags, [':', ' '], $i, false, []);
432
433            if ($offsetBeforeKeyParsing === $i) {
434                throw new ParseException('Missing mapping key.', self::$parsedLineNumber + 1, $mapping);
435            }
436
437            if (false === $i = strpos($mapping, ':', $i)) {
438                break;
439            }
440
441            if (!$isKeyQuoted) {
442                $evaluatedKey = self::evaluateScalar($key, $flags, $references);
443
444                if ('' !== $key && $evaluatedKey !== $key && !\is_string($evaluatedKey) && !\is_int($evaluatedKey)) {
445                    throw new ParseException('Implicit casting of incompatible mapping keys to strings is not supported. Quote your evaluable mapping keys instead.', self::$parsedLineNumber + 1, $mapping);
446                }
447            }
448
449            if (!$isKeyQuoted && (!isset($mapping[$i + 1]) || !\in_array($mapping[$i + 1], [' ', ',', '[', ']', '{', '}'], true))) {
450                throw new ParseException('Colons must be followed by a space or an indication character (i.e. " ", ",", "[", "]", "{", "}").', self::$parsedLineNumber + 1, $mapping);
451            }
452
453            if ('<<' === $key) {
454                $allowOverwrite = true;
455            }
456
457            while ($i < $len) {
458                if (':' === $mapping[$i] || ' ' === $mapping[$i]) {
459                    ++$i;
460
461                    continue;
462                }
463
464                $tag = self::parseTag($mapping, $i, $flags);
465                switch ($mapping[$i]) {
466                    case '[':
467                        // nested sequence
468                        $value = self::parseSequence($mapping, $flags, $i, $references);
469                        // Spec: Keys MUST be unique; first one wins.
470                        // Parser cannot abort this mapping earlier, since lines
471                        // are processed sequentially.
472                        // But overwriting is allowed when a merge node is used in current block.
473                        if ('<<' === $key) {
474                            foreach ($value as $parsedValue) {
475                                $output += $parsedValue;
476                            }
477                        } elseif ($allowOverwrite || !isset($output[$key])) {
478                            if (null !== $tag) {
479                                $output[$key] = new TaggedValue($tag, $value);
480                            } else {
481                                $output[$key] = $value;
482                            }
483                        } elseif (isset($output[$key])) {
484                            throw new ParseException(sprintf('Duplicate key "%s" detected.', $key), self::$parsedLineNumber + 1, $mapping);
485                        }
486                        break;
487                    case '{':
488                        // nested mapping
489                        $value = self::parseMapping($mapping, $flags, $i, $references);
490                        // Spec: Keys MUST be unique; first one wins.
491                        // Parser cannot abort this mapping earlier, since lines
492                        // are processed sequentially.
493                        // But overwriting is allowed when a merge node is used in current block.
494                        if ('<<' === $key) {
495                            $output += $value;
496                        } elseif ($allowOverwrite || !isset($output[$key])) {
497                            if (null !== $tag) {
498                                $output[$key] = new TaggedValue($tag, $value);
499                            } else {
500                                $output[$key] = $value;
501                            }
502                        } elseif (isset($output[$key])) {
503                            throw new ParseException(sprintf('Duplicate key "%s" detected.', $key), self::$parsedLineNumber + 1, $mapping);
504                        }
505                        break;
506                    default:
507                        $value = self::parseScalar($mapping, $flags, [',', '}'], $i, null === $tag, $references);
508                        // Spec: Keys MUST be unique; first one wins.
509                        // Parser cannot abort this mapping earlier, since lines
510                        // are processed sequentially.
511                        // But overwriting is allowed when a merge node is used in current block.
512                        if ('<<' === $key) {
513                            $output += $value;
514                        } elseif ($allowOverwrite || !isset($output[$key])) {
515                            if (null !== $tag) {
516                                $output[$key] = new TaggedValue($tag, $value);
517                            } else {
518                                $output[$key] = $value;
519                            }
520                        } elseif (isset($output[$key])) {
521                            throw new ParseException(sprintf('Duplicate key "%s" detected.', $key), self::$parsedLineNumber + 1, $mapping);
522                        }
523                        --$i;
524                }
525                ++$i;
526
527                continue 2;
528            }
529        }
530
531        throw new ParseException(sprintf('Malformed inline YAML string: %s.', $mapping), self::$parsedLineNumber + 1, null, self::$parsedFilename);
532    }
533
534    /**
535     * Evaluates scalars and replaces magic values.
536     *
537     * @return mixed The evaluated YAML string
538     *
539     * @throws ParseException when object parsing support was disabled and the parser detected a PHP object or when a reference could not be resolved
540     */
541    private static function evaluateScalar(string $scalar, int $flags, array $references = [])
542    {
543        $scalar = trim($scalar);
544        $scalarLower = strtolower($scalar);
545
546        if (0 === strpos($scalar, '*')) {
547            if (false !== $pos = strpos($scalar, '#')) {
548                $value = substr($scalar, 1, $pos - 2);
549            } else {
550                $value = substr($scalar, 1);
551            }
552
553            // an unquoted *
554            if (false === $value || '' === $value) {
555                throw new ParseException('A reference must contain at least one character.', self::$parsedLineNumber + 1, $value, self::$parsedFilename);
556            }
557
558            if (!\array_key_exists($value, $references)) {
559                throw new ParseException(sprintf('Reference "%s" does not exist.', $value), self::$parsedLineNumber + 1, $value, self::$parsedFilename);
560            }
561
562            return $references[$value];
563        }
564
565        switch (true) {
566            case 'null' === $scalarLower:
567            case '' === $scalar:
568            case '~' === $scalar:
569                return;
570            case 'true' === $scalarLower:
571                return true;
572            case 'false' === $scalarLower:
573                return false;
574            case '!' === $scalar[0]:
575                switch (true) {
576                    case 0 === strpos($scalar, '!!str '):
577                        return (string) substr($scalar, 6);
578                    case 0 === strpos($scalar, '! '):
579                        return substr($scalar, 2);
580                    case 0 === strpos($scalar, '!php/object'):
581                        if (self::$objectSupport) {
582                            return unserialize(self::parseScalar(substr($scalar, 12)));
583                        }
584
585                        if (self::$exceptionOnInvalidType) {
586                            throw new ParseException('Object support when parsing a YAML file has been disabled.', self::$parsedLineNumber + 1, $scalar, self::$parsedFilename);
587                        }
588
589                        return;
590                    case 0 === strpos($scalar, '!php/const'):
591                        if (self::$constantSupport) {
592                            $i = 0;
593                            if (\defined($const = self::parseScalar(substr($scalar, 11), 0, null, $i, false))) {
594                                return \constant($const);
595                            }
596
597                            throw new ParseException(sprintf('The constant "%s" is not defined.', $const), self::$parsedLineNumber + 1, $scalar, self::$parsedFilename);
598                        }
599                        if (self::$exceptionOnInvalidType) {
600                            throw new ParseException(sprintf('The string "%s" could not be parsed as a constant. Have you forgotten to pass the "Yaml::PARSE_CONSTANT" flag to the parser?', $scalar), self::$parsedLineNumber + 1, $scalar, self::$parsedFilename);
601                        }
602
603                        return;
604                    case 0 === strpos($scalar, '!!float '):
605                        return (float) substr($scalar, 8);
606                    case 0 === strpos($scalar, '!!binary '):
607                        return self::evaluateBinaryScalar(substr($scalar, 9));
608                    default:
609                        throw new ParseException(sprintf('The string "%s" could not be parsed as it uses an unsupported built-in tag.', $scalar), self::$parsedLineNumber, $scalar, self::$parsedFilename);
610                }
611
612            // Optimize for returning strings.
613            // no break
614            case '+' === $scalar[0] || '-' === $scalar[0] || '.' === $scalar[0] || is_numeric($scalar[0]):
615                switch (true) {
616                    case Parser::preg_match('{^[+-]?[0-9][0-9_]*$}', $scalar):
617                        $scalar = str_replace('_', '', (string) $scalar);
618                        // omitting the break / return as integers are handled in the next case
619                        // no break
620                    case ctype_digit($scalar):
621                        $raw = $scalar;
622                        $cast = (int) $scalar;
623
624                        return '0' == $scalar[0] ? octdec($scalar) : (((string) $raw == (string) $cast) ? $cast : $raw);
625                    case '-' === $scalar[0] && ctype_digit(substr($scalar, 1)):
626                        $raw = $scalar;
627                        $cast = (int) $scalar;
628
629                        return '0' == $scalar[1] ? octdec($scalar) : (((string) $raw === (string) $cast) ? $cast : $raw);
630                    case is_numeric($scalar):
631                    case Parser::preg_match(self::getHexRegex(), $scalar):
632                        $scalar = str_replace('_', '', $scalar);
633
634                        return '0x' === $scalar[0].$scalar[1] ? hexdec($scalar) : (float) $scalar;
635                    case '.inf' === $scalarLower:
636                    case '.nan' === $scalarLower:
637                        return -log(0);
638                    case '-.inf' === $scalarLower:
639                        return log(0);
640                    case Parser::preg_match('/^(-|\+)?[0-9][0-9_]*(\.[0-9_]+)?$/', $scalar):
641                        return (float) str_replace('_', '', $scalar);
642                    case Parser::preg_match(self::getTimestampRegex(), $scalar):
643                        if (Yaml::PARSE_DATETIME & $flags) {
644                            // When no timezone is provided in the parsed date, YAML spec says we must assume UTC.
645                            return new \DateTime($scalar, new \DateTimeZone('UTC'));
646                        }
647
648                        $timeZone = date_default_timezone_get();
649                        date_default_timezone_set('UTC');
650                        $time = strtotime($scalar);
651                        date_default_timezone_set($timeZone);
652
653                        return $time;
654                }
655        }
656
657        return (string) $scalar;
658    }
659
660    private static function parseTag(string $value, int &$i, int $flags): ?string
661    {
662        if ('!' !== $value[$i]) {
663            return null;
664        }
665
666        $tagLength = strcspn($value, " \t\n[]{},", $i + 1);
667        $tag = substr($value, $i + 1, $tagLength);
668
669        $nextOffset = $i + $tagLength + 1;
670        $nextOffset += strspn($value, ' ', $nextOffset);
671
672        // Is followed by a scalar and is a built-in tag
673        if ($tag && (!isset($value[$nextOffset]) || !\in_array($value[$nextOffset], ['[', '{'], true)) && ('!' === $tag[0] || 'str' === $tag || 'php/const' === $tag || 'php/object' === $tag)) {
674            // Manage in {@link self::evaluateScalar()}
675            return null;
676        }
677
678        $i = $nextOffset;
679
680        // Built-in tags
681        if ($tag && '!' === $tag[0]) {
682            throw new ParseException(sprintf('The built-in tag "!%s" is not implemented.', $tag), self::$parsedLineNumber + 1, $value, self::$parsedFilename);
683        }
684
685        if ('' === $tag || Yaml::PARSE_CUSTOM_TAGS & $flags) {
686            return $tag;
687        }
688
689        throw new ParseException(sprintf('Tags support is not enabled. Enable the "Yaml::PARSE_CUSTOM_TAGS" flag to use "!%s".', $tag), self::$parsedLineNumber + 1, $value, self::$parsedFilename);
690    }
691
692    public static function evaluateBinaryScalar(string $scalar): string
693    {
694        $parsedBinaryData = self::parseScalar(preg_replace('/\s/', '', $scalar));
695
696        if (0 !== (\strlen($parsedBinaryData) % 4)) {
697            throw new ParseException(sprintf('The normalized base64 encoded data (data without whitespace characters) length must be a multiple of four (%d bytes given).', \strlen($parsedBinaryData)), self::$parsedLineNumber + 1, $scalar, self::$parsedFilename);
698        }
699
700        if (!Parser::preg_match('#^[A-Z0-9+/]+={0,2}$#i', $parsedBinaryData)) {
701            throw new ParseException(sprintf('The base64 encoded data (%s) contains invalid characters.', $parsedBinaryData), self::$parsedLineNumber + 1, $scalar, self::$parsedFilename);
702        }
703
704        return base64_decode($parsedBinaryData, true);
705    }
706
707    private static function isBinaryString(string $value)
708    {
709        return !preg_match('//u', $value) || preg_match('/[^\x00\x07-\x0d\x1B\x20-\xff]/', $value);
710    }
711
712    /**
713     * Gets a regex that matches a YAML date.
714     *
715     * @return string The regular expression
716     *
717     * @see http://www.yaml.org/spec/1.2/spec.html#id2761573
718     */
719    private static function getTimestampRegex(): string
720    {
721        return <<<EOF
722        ~^
723        (?P<year>[0-9][0-9][0-9][0-9])
724        -(?P<month>[0-9][0-9]?)
725        -(?P<day>[0-9][0-9]?)
726        (?:(?:[Tt]|[ \t]+)
727        (?P<hour>[0-9][0-9]?)
728        :(?P<minute>[0-9][0-9])
729        :(?P<second>[0-9][0-9])
730        (?:\.(?P<fraction>[0-9]*))?
731        (?:[ \t]*(?P<tz>Z|(?P<tz_sign>[-+])(?P<tz_hour>[0-9][0-9]?)
732        (?::(?P<tz_minute>[0-9][0-9]))?))?)?
733        $~x
734EOF;
735    }
736
737    /**
738     * Gets a regex that matches a YAML number in hexadecimal notation.
739     *
740     * @return string
741     */
742    private static function getHexRegex(): string
743    {
744        return '~^0x[0-9a-f_]++$~i';
745    }
746}
747