Inline.php

<?php

/*
 * This file is part of the Symfony package.
 * (c) Fabien Potencier <fabien@symfony.com>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */
namespace Symfony\Component\Yaml;

use Symfony\Component\Yaml\Exception\ParseException;
use Symfony\Component\Yaml\Exception\DumpException;

/**
 * Inline implements a YAML parser/dumper for the YAML inline syntax.
 *
 * @author Fabien Potencier <fabien@symfony.com>
 */
class Inline {
  const REGEX_QUOTED_STRING = '(?:"([^"\\\\]*(?:\\\\.[^"\\\\]*)*)"|\'([^\']*(?:\'\'[^\']*)*)\')';

  /**
   * Converts a YAML string to a PHP array.
   *
   * @param string $value A YAML string
   *
   * @return array A PHP array representing the YAML string
   */
  public static function parse($value) {
    $value = trim($value);
    if (0 == strlen($value)) {
      return '';
    }
    if (function_exists('mb_internal_encoding') && (int) ini_get('mbstring.func_overload') & 2) {
      $mbEncoding = mb_internal_encoding();
      mb_internal_encoding('ASCII');
    }
    switch ($value[0]) {
      case '[':
        $result = self::parseSequence($value);
        break;
      case '{':
        $result = self::parseMapping($value);
        break;
      default:
        $i = 0;
        $result = self::parseScalar($value, null, array(
          '"',
          "'",
        ), $i);

        // some comment can end the scalar
        if (preg_replace('/\\s+#.*$/A', '', substr($value, $i))) {
          throw new ParseException(sprintf('Unexpected characters near "%s".', substr($value, $i)));
        }
    }
    if (isset($mbEncoding)) {
      mb_internal_encoding($mbEncoding);
    }
    return $result;
  }

  /**
   * Dumps a given PHP variable to a YAML string.
   *
   * @param mixed $value The PHP variable to convert
   *
   * @return string The YAML string representing the PHP array
   *
   * @throws DumpException When trying to dump PHP resource
   */
  public static function dump($value) {
    switch (true) {
      case is_resource($value):
        throw new DumpException(sprintf('Unable to dump PHP resources in a YAML file ("%s").', get_resource_type($value)));
      case is_object($value):
        return '!!php/object:' . serialize($value);
      case is_array($value):
        return self::dumpArray($value);
      case null === $value:
        return 'null';
      case true === $value:
        return 'true';
      case false === $value:
        return 'false';
      case ctype_digit($value):
        return is_string($value) ? "'{$value}'" : (int) $value;
      case is_numeric($value):
        $locale = setlocale(LC_NUMERIC, 0);
        if (false !== $locale) {
          setlocale(LC_NUMERIC, 'C');
        }
        $repr = is_string($value) ? "'{$value}'" : (is_infinite($value) ? str_ireplace('INF', '.Inf', strval($value)) : strval($value));
        if (false !== $locale) {
          setlocale(LC_NUMERIC, $locale);
        }
        return $repr;
      case Escaper::requiresDoubleQuoting($value):
        return Escaper::escapeWithDoubleQuotes($value);
      case Escaper::requiresSingleQuoting($value):
        return Escaper::escapeWithSingleQuotes($value);
      case '' == $value:
        return "''";
      case preg_match(self::getTimestampRegex(), $value):
      case in_array(strtolower($value), array(
        'null',
        '~',
        'true',
        'false',
      )):
        return "'{$value}'";
      default:
        return $value;
    }
  }

  /**
   * Dumps a PHP array to a YAML string.
   *
   * @param array $value The PHP array to dump
   *
   * @return string The YAML string representing the PHP array
   */
  private static function dumpArray($value) {

    // array
    $keys = array_keys($value);
    if (1 == count($keys) && '0' == $keys[0] || count($keys) > 1 && array_reduce($keys, function ($v, $w) {
      return (int) $v + $w;
    }, 0) == count($keys) * (count($keys) - 1) / 2) {
      $output = array();
      foreach ($value as $val) {
        $output[] = self::dump($val);
      }
      return sprintf('[%s]', implode(', ', $output));
    }

    // mapping
    $output = array();
    foreach ($value as $key => $val) {
      $output[] = sprintf('%s: %s', self::dump($key), self::dump($val));
    }
    return sprintf('{ %s }', implode(', ', $output));
  }

  /**
   * Parses a scalar to a YAML string.
   *
   * @param scalar $scalar
   * @param string $delimiters
   * @param array  $stringDelimiters
   * @param integer &$i
   * @param Boolean $evaluate
   *
   * @return string A YAML string
   *
   * @throws ParseException When malformed inline YAML string is parsed
   */
  public static function parseScalar($scalar, $delimiters = null, $stringDelimiters = array(
    '"',
    "'",
  ), &$i = 0, $evaluate = true) {
    if (in_array($scalar[$i], $stringDelimiters)) {

      // quoted scalar
      $output = self::parseQuotedScalar($scalar, $i);
      if (null !== $delimiters) {
        $tmp = ltrim(substr($scalar, $i), ' ');
        if (!in_array($tmp[0], $delimiters)) {
          throw new ParseException(sprintf('Unexpected characters (%s).', substr($scalar, $i)));
        }
      }
    }
    else {

      // "normal" string
      if (!$delimiters) {
        $output = substr($scalar, $i);
        $i += strlen($output);

        // remove comments
        if (false !== ($strpos = strpos($output, ' #'))) {
          $output = rtrim(substr($output, 0, $strpos));
        }
      }
      elseif (preg_match('/^(.+?)(' . implode('|', $delimiters) . ')/', substr($scalar, $i), $match)) {
        $output = $match[1];
        $i += strlen($output);
      }
      else {
        throw new ParseException(sprintf('Malformed inline YAML string (%s).', $scalar));
      }
      $output = $evaluate ? self::evaluateScalar($output) : $output;
    }
    return $output;
  }

  /**
   * Parses a quoted scalar to YAML.
   *
   * @param string $scalar
   * @param integer &$i
   *
   * @return string A YAML string
   *
   * @throws ParseException When malformed inline YAML string is parsed
   */
  private static function parseQuotedScalar($scalar, &$i) {

    // Only check the current item we're dealing with (for sequences)
    $subject = substr($scalar, $i);
    $items = preg_split('/[\'"]\\s*(?:[,:]|[}\\]]\\s*,)/', $subject);
    $subject = substr($subject, 0, strlen($items[0]) + 1);
    if (!preg_match('/' . self::REGEX_QUOTED_STRING . '/Au', substr($scalar, $i), $match)) {
      throw new ParseException(sprintf('Malformed inline YAML string (%s).', substr($scalar, $i)));
    }
    $output = substr($match[0], 1, strlen($match[0]) - 2);
    $unescaper = new Unescaper();
    if ('"' == $scalar[$i]) {
      $output = $unescaper
        ->unescapeDoubleQuotedString($output);
    }
    else {
      $output = $unescaper
        ->unescapeSingleQuotedString($output);
    }
    $i += strlen($match[0]);
    return $output;
  }

  /**
   * Parses a sequence to a YAML string.
   *
   * @param string $sequence
   * @param integer &$i
   *
   * @return string A YAML string
   *
   * @throws ParseException When malformed inline YAML string is parsed
   */
  private static function parseSequence($sequence, &$i = 0) {
    $output = array();
    $len = strlen($sequence);
    $i += 1;

    // [foo, bar, ...]
    while ($i < $len) {
      switch ($sequence[$i]) {
        case '[':

          // nested sequence
          $output[] = self::parseSequence($sequence, $i);
          break;
        case '{':

          // nested mapping
          $output[] = self::parseMapping($sequence, $i);
          break;
        case ']':
          return $output;
        case ',':
        case ' ':
          break;
        default:
          $isQuoted = in_array($sequence[$i], array(
            '"',
            "'",
          ));
          $value = self::parseScalar($sequence, array(
            ',',
            ']',
          ), array(
            '"',
            "'",
          ), $i);
          if (!$isQuoted && false !== strpos($value, ': ')) {

            // embedded mapping?
            try {
              $value = self::parseMapping('{' . $value . '}');
            } catch (\InvalidArgumentException $e) {

              // no, it's not
            }
          }
          $output[] = $value;
          --$i;
      }
      ++$i;
    }
    throw new ParseException(sprintf('Malformed inline YAML string %s', $sequence));
  }

  /**
   * Parses a mapping to a YAML string.
   *
   * @param string $mapping
   * @param integer &$i
   *
   * @return string A YAML string
   *
   * @throws ParseException When malformed inline YAML string is parsed
   */
  private static function parseMapping($mapping, &$i = 0) {
    $output = array();
    $len = strlen($mapping);
    $i += 1;

    // {foo: bar, bar:foo, ...}
    while ($i < $len) {
      switch ($mapping[$i]) {
        case ' ':
        case ',':
          ++$i;
          continue 2;
        case '}':
          return $output;
      }

      // key
      $key = self::parseScalar($mapping, array(
        ':',
        ' ',
      ), array(
        '"',
        "'",
      ), $i, false);

      // value
      $done = false;
      while ($i < $len) {
        switch ($mapping[$i]) {
          case '[':

            // nested sequence
            $output[$key] = self::parseSequence($mapping, $i);
            $done = true;
            break;
          case '{':

            // nested mapping
            $output[$key] = self::parseMapping($mapping, $i);
            $done = true;
            break;
          case ':':
          case ' ':
            break;
          default:
            $output[$key] = self::parseScalar($mapping, array(
              ',',
              '}',
            ), array(
              '"',
              "'",
            ), $i);
            $done = true;
            --$i;
        }
        ++$i;
        if ($done) {
          continue 2;
        }
      }
    }
    throw new ParseException(sprintf('Malformed inline YAML string %s', $mapping));
  }

  /**
   * Evaluates scalars and replaces magic values.
   *
   * @param string $scalar
   *
   * @return string A YAML string
   */
  private static function evaluateScalar($scalar) {
    $scalar = trim($scalar);
    switch (true) {
      case 'null' == strtolower($scalar):
      case '' == $scalar:
      case '~' == $scalar:
        return null;
      case 0 === strpos($scalar, '!str'):
        return (string) substr($scalar, 5);
      case 0 === strpos($scalar, '! '):
        return intval(self::parseScalar(substr($scalar, 2)));
      case 0 === strpos($scalar, '!!php/object:'):
        return unserialize(substr($scalar, 13));
      case ctype_digit($scalar):
        $raw = $scalar;
        $cast = intval($scalar);
        return '0' == $scalar[0] ? octdec($scalar) : ((string) $raw == (string) $cast ? $cast : $raw);
      case 'true' === strtolower($scalar):
        return true;
      case 'false' === strtolower($scalar):
        return false;
      case is_numeric($scalar):
        return '0x' == $scalar[0] . $scalar[1] ? hexdec($scalar) : floatval($scalar);
      case 0 == strcasecmp($scalar, '.inf'):
      case 0 == strcasecmp($scalar, '.NaN'):
        return -log(0);
      case 0 == strcasecmp($scalar, '-.inf'):
        return log(0);
      case preg_match('/^(-|\\+)?[0-9,]+(\\.[0-9]+)?$/', $scalar):
        return floatval(str_replace(',', '', $scalar));
      case preg_match(self::getTimestampRegex(), $scalar):
        return strtotime($scalar);
      default:
        return (string) $scalar;
    }
  }

  /**
   * Gets a regex that matches an unix timestamp
   *
   * @return string The regular expression
   */
  private static function getTimestampRegex() {
    return <<<EOF
        ~^
        (?P<year>[0-9][0-9][0-9][0-9])
        -(?P<month>[0-9][0-9]?)
        -(?P<day>[0-9][0-9]?)
        (?:(?:[Tt]|[ \t]+)
        (?P<hour>[0-9][0-9]?)
        :(?P<minute>[0-9][0-9])
        :(?P<second>[0-9][0-9])
        (?:\\.(?P<fraction>[0-9]*))?
        (?:[ \t]*(?P<tz>Z|(?P<tz_sign>[-+])(?P<tz_hour>[0-9][0-9]?)
        (?::(?P<tz_minute>[0-9][0-9]))?))?)?
        \$~x
EOF;
  }

}