Chris@0: <?php
Chris@0: 
Chris@0: /*
Chris@0:  * This file is part of composer/semver.
Chris@0:  *
Chris@0:  * (c) Composer <https://github.com/composer>
Chris@0:  *
Chris@0:  * For the full copyright and license information, please view
Chris@0:  * the LICENSE file that was distributed with this source code.
Chris@0:  */
Chris@0: 
Chris@0: namespace Composer\Semver;
Chris@0: 
Chris@0: use Composer\Semver\Constraint\ConstraintInterface;
Chris@0: use Composer\Semver\Constraint\EmptyConstraint;
Chris@0: use Composer\Semver\Constraint\MultiConstraint;
Chris@0: use Composer\Semver\Constraint\Constraint;
Chris@0: 
Chris@0: /**
Chris@0:  * Version parser.
Chris@0:  *
Chris@0:  * @author Jordi Boggiano <j.boggiano@seld.be>
Chris@0:  */
Chris@0: class VersionParser
Chris@0: {
Chris@0:     /**
Chris@0:      * Regex to match pre-release data (sort of).
Chris@0:      *
Chris@0:      * Due to backwards compatibility:
Chris@0:      *   - Instead of enforcing hyphen, an underscore, dot or nothing at all are also accepted.
Chris@0:      *   - Only stabilities as recognized by Composer are allowed to precede a numerical identifier.
Chris@0:      *   - Numerical-only pre-release identifiers are not supported, see tests.
Chris@0:      *
Chris@0:      *                        |--------------|
Chris@0:      * [major].[minor].[patch] -[pre-release] +[build-metadata]
Chris@0:      *
Chris@0:      * @var string
Chris@0:      */
Chris@0:     private static $modifierRegex = '[._-]?(?:(stable|beta|b|RC|alpha|a|patch|pl|p)((?:[.-]?\d+)*+)?)?([.-]?dev)?';
Chris@0: 
Chris@0:     /** @var array */
Chris@0:     private static $stabilities = array('stable', 'RC', 'beta', 'alpha', 'dev');
Chris@0: 
Chris@0:     /**
Chris@0:      * Returns the stability of a version.
Chris@0:      *
Chris@0:      * @param string $version
Chris@0:      *
Chris@0:      * @return string
Chris@0:      */
Chris@0:     public static function parseStability($version)
Chris@0:     {
Chris@0:         $version = preg_replace('{#.+$}i', '', $version);
Chris@0: 
Chris@0:         if ('dev-' === substr($version, 0, 4) || '-dev' === substr($version, -4)) {
Chris@0:             return 'dev';
Chris@0:         }
Chris@0: 
Chris@0:         preg_match('{' . self::$modifierRegex . '(?:\+.*)?$}i', strtolower($version), $match);
Chris@0:         if (!empty($match[3])) {
Chris@0:             return 'dev';
Chris@0:         }
Chris@0: 
Chris@0:         if (!empty($match[1])) {
Chris@0:             if ('beta' === $match[1] || 'b' === $match[1]) {
Chris@0:                 return 'beta';
Chris@0:             }
Chris@0:             if ('alpha' === $match[1] || 'a' === $match[1]) {
Chris@0:                 return 'alpha';
Chris@0:             }
Chris@0:             if ('rc' === $match[1]) {
Chris@0:                 return 'RC';
Chris@0:             }
Chris@0:         }
Chris@0: 
Chris@0:         return 'stable';
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * @param string $stability
Chris@0:      *
Chris@0:      * @return string
Chris@0:      */
Chris@0:     public static function normalizeStability($stability)
Chris@0:     {
Chris@0:         $stability = strtolower($stability);
Chris@0: 
Chris@0:         return $stability === 'rc' ? 'RC' : $stability;
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * Normalizes a version string to be able to perform comparisons on it.
Chris@0:      *
Chris@0:      * @param string $version
Chris@0:      * @param string $fullVersion optional complete version string to give more context
Chris@0:      *
Chris@0:      * @throws \UnexpectedValueException
Chris@0:      *
Chris@0:      * @return string
Chris@0:      */
Chris@0:     public function normalize($version, $fullVersion = null)
Chris@0:     {
Chris@0:         $version = trim($version);
Chris@0:         if (null === $fullVersion) {
Chris@0:             $fullVersion = $version;
Chris@0:         }
Chris@0: 
Chris@0:         // strip off aliasing
Chris@0:         if (preg_match('{^([^,\s]++) ++as ++([^,\s]++)$}', $version, $match)) {
Chris@0:             $version = $match[1];
Chris@0:         }
Chris@0: 
Chris@0:         // match master-like branches
Chris@0:         if (preg_match('{^(?:dev-)?(?:master|trunk|default)$}i', $version)) {
Chris@0:             return '9999999-dev';
Chris@0:         }
Chris@0: 
Chris@0:         // if requirement is branch-like, use full name
Chris@0:         if ('dev-' === strtolower(substr($version, 0, 4))) {
Chris@0:             return 'dev-' . substr($version, 4);
Chris@0:         }
Chris@0: 
Chris@0:         // strip off build metadata
Chris@0:         if (preg_match('{^([^,\s+]++)\+[^\s]++$}', $version, $match)) {
Chris@0:             $version = $match[1];
Chris@0:         }
Chris@0: 
Chris@0:         // match classical versioning
Chris@0:         if (preg_match('{^v?(\d{1,5})(\.\d++)?(\.\d++)?(\.\d++)?' . self::$modifierRegex . '$}i', $version, $matches)) {
Chris@0:             $version = $matches[1]
Chris@0:                 . (!empty($matches[2]) ? $matches[2] : '.0')
Chris@0:                 . (!empty($matches[3]) ? $matches[3] : '.0')
Chris@0:                 . (!empty($matches[4]) ? $matches[4] : '.0');
Chris@0:             $index = 5;
Chris@0:         // match date(time) based versioning
Chris@0:         } elseif (preg_match('{^v?(\d{4}(?:[.:-]?\d{2}){1,6}(?:[.:-]?\d{1,3})?)' . self::$modifierRegex . '$}i', $version, $matches)) {
Chris@0:             $version = preg_replace('{\D}', '.', $matches[1]);
Chris@0:             $index = 2;
Chris@0:         }
Chris@0: 
Chris@0:         // add version modifiers if a version was matched
Chris@0:         if (isset($index)) {
Chris@0:             if (!empty($matches[$index])) {
Chris@0:                 if ('stable' === $matches[$index]) {
Chris@0:                     return $version;
Chris@0:                 }
Chris@0:                 $version .= '-' . $this->expandStability($matches[$index]) . (!empty($matches[$index + 1]) ? ltrim($matches[$index + 1], '.-') : '');
Chris@0:             }
Chris@0: 
Chris@0:             if (!empty($matches[$index + 2])) {
Chris@0:                 $version .= '-dev';
Chris@0:             }
Chris@0: 
Chris@0:             return $version;
Chris@0:         }
Chris@0: 
Chris@0:         // match dev branches
Chris@0:         if (preg_match('{(.*?)[.-]?dev$}i', $version, $match)) {
Chris@0:             try {
Chris@0:                 return $this->normalizeBranch($match[1]);
Chris@0:             } catch (\Exception $e) {
Chris@0:             }
Chris@0:         }
Chris@0: 
Chris@0:         $extraMessage = '';
Chris@0:         if (preg_match('{ +as +' . preg_quote($version) . '$}', $fullVersion)) {
Chris@0:             $extraMessage = ' in "' . $fullVersion . '", the alias must be an exact version';
Chris@0:         } elseif (preg_match('{^' . preg_quote($version) . ' +as +}', $fullVersion)) {
Chris@0:             $extraMessage = ' in "' . $fullVersion . '", the alias source must be an exact version, if it is a branch name you should prefix it with dev-';
Chris@0:         }
Chris@0: 
Chris@0:         throw new \UnexpectedValueException('Invalid version string "' . $version . '"' . $extraMessage);
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * Extract numeric prefix from alias, if it is in numeric format, suitable for version comparison.
Chris@0:      *
Chris@0:      * @param string $branch Branch name (e.g. 2.1.x-dev)
Chris@0:      *
Chris@0:      * @return string|false Numeric prefix if present (e.g. 2.1.) or false
Chris@0:      */
Chris@0:     public function parseNumericAliasPrefix($branch)
Chris@0:     {
Chris@0:         if (preg_match('{^(?P<version>(\d++\\.)*\d++)(?:\.x)?-dev$}i', $branch, $matches)) {
Chris@0:             return $matches['version'] . '.';
Chris@0:         }
Chris@0: 
Chris@0:         return false;
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * Normalizes a branch name to be able to perform comparisons on it.
Chris@0:      *
Chris@0:      * @param string $name
Chris@0:      *
Chris@0:      * @return string
Chris@0:      */
Chris@0:     public function normalizeBranch($name)
Chris@0:     {
Chris@0:         $name = trim($name);
Chris@0: 
Chris@0:         if (in_array($name, array('master', 'trunk', 'default'))) {
Chris@0:             return $this->normalize($name);
Chris@0:         }
Chris@0: 
Chris@0:         if (preg_match('{^v?(\d++)(\.(?:\d++|[xX*]))?(\.(?:\d++|[xX*]))?(\.(?:\d++|[xX*]))?$}i', $name, $matches)) {
Chris@0:             $version = '';
Chris@0:             for ($i = 1; $i < 5; ++$i) {
Chris@0:                 $version .= isset($matches[$i]) ? str_replace(array('*', 'X'), 'x', $matches[$i]) : '.x';
Chris@0:             }
Chris@0: 
Chris@0:             return str_replace('x', '9999999', $version) . '-dev';
Chris@0:         }
Chris@0: 
Chris@0:         return 'dev-' . $name;
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * Parses a constraint string into MultiConstraint and/or Constraint objects.
Chris@0:      *
Chris@0:      * @param string $constraints
Chris@0:      *
Chris@0:      * @return ConstraintInterface
Chris@0:      */
Chris@0:     public function parseConstraints($constraints)
Chris@0:     {
Chris@0:         $prettyConstraint = $constraints;
Chris@0: 
Chris@0:         if (preg_match('{^([^,\s]*?)@(' . implode('|', self::$stabilities) . ')$}i', $constraints, $match)) {
Chris@0:             $constraints = empty($match[1]) ? '*' : $match[1];
Chris@0:         }
Chris@0: 
Chris@0:         if (preg_match('{^(dev-[^,\s@]+?|[^,\s@]+?\.x-dev)#.+$}i', $constraints, $match)) {
Chris@0:             $constraints = $match[1];
Chris@0:         }
Chris@0: 
Chris@0:         $orConstraints = preg_split('{\s*\|\|?\s*}', trim($constraints));
Chris@0:         $orGroups = array();
Chris@0:         foreach ($orConstraints as $constraints) {
Chris@0:             $andConstraints = preg_split('{(?<!^|as|[=>< ,]) *(?<!-)[, ](?!-) *(?!,|as|$)}', $constraints);
Chris@0:             if (count($andConstraints) > 1) {
Chris@0:                 $constraintObjects = array();
Chris@0:                 foreach ($andConstraints as $constraint) {
Chris@0:                     foreach ($this->parseConstraint($constraint) as $parsedConstraint) {
Chris@0:                         $constraintObjects[] = $parsedConstraint;
Chris@0:                     }
Chris@0:                 }
Chris@0:             } else {
Chris@0:                 $constraintObjects = $this->parseConstraint($andConstraints[0]);
Chris@0:             }
Chris@0: 
Chris@0:             if (1 === count($constraintObjects)) {
Chris@0:                 $constraint = $constraintObjects[0];
Chris@0:             } else {
Chris@0:                 $constraint = new MultiConstraint($constraintObjects);
Chris@0:             }
Chris@0: 
Chris@0:             $orGroups[] = $constraint;
Chris@0:         }
Chris@0: 
Chris@0:         if (1 === count($orGroups)) {
Chris@0:             $constraint = $orGroups[0];
Chris@0:         } elseif (2 === count($orGroups)
Chris@0:             // parse the two OR groups and if they are contiguous we collapse
Chris@0:             // them into one constraint
Chris@0:             && $orGroups[0] instanceof MultiConstraint
Chris@0:             && $orGroups[1] instanceof MultiConstraint
Chris@0:             && 2 === count($orGroups[0]->getConstraints())
Chris@0:             && 2 === count($orGroups[1]->getConstraints())
Chris@0:             && ($a = (string) $orGroups[0])
Chris@0:             && substr($a, 0, 3) === '[>=' && (false !== ($posA = strpos($a, '<', 4)))
Chris@0:             && ($b = (string) $orGroups[1])
Chris@0:             && substr($b, 0, 3) === '[>=' && (false !== ($posB = strpos($b, '<', 4)))
Chris@0:             && substr($a, $posA + 2, -1) === substr($b, 4, $posB - 5)
Chris@0:         ) {
Chris@0:             $constraint = new MultiConstraint(array(
Chris@0:                 new Constraint('>=', substr($a, 4, $posA - 5)),
Chris@0:                 new Constraint('<', substr($b, $posB + 2, -1)),
Chris@0:             ));
Chris@0:         } else {
Chris@0:             $constraint = new MultiConstraint($orGroups, false);
Chris@0:         }
Chris@0: 
Chris@0:         $constraint->setPrettyString($prettyConstraint);
Chris@0: 
Chris@0:         return $constraint;
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * @param string $constraint
Chris@0:      *
Chris@0:      * @throws \UnexpectedValueException
Chris@0:      *
Chris@0:      * @return array
Chris@0:      */
Chris@0:     private function parseConstraint($constraint)
Chris@0:     {
Chris@0:         if (preg_match('{^([^,\s]+?)@(' . implode('|', self::$stabilities) . ')$}i', $constraint, $match)) {
Chris@0:             $constraint = $match[1];
Chris@0:             if ($match[2] !== 'stable') {
Chris@0:                 $stabilityModifier = $match[2];
Chris@0:             }
Chris@0:         }
Chris@0: 
Chris@0:         if (preg_match('{^v?[xX*](\.[xX*])*$}i', $constraint)) {
Chris@0:             return array(new EmptyConstraint());
Chris@0:         }
Chris@0: 
Chris@0:         $versionRegex = 'v?(\d++)(?:\.(\d++))?(?:\.(\d++))?(?:\.(\d++))?' . self::$modifierRegex . '(?:\+[^\s]+)?';
Chris@0: 
Chris@0:         // Tilde Range
Chris@0:         //
Chris@0:         // Like wildcard constraints, unsuffixed tilde constraints say that they must be greater than the previous
Chris@0:         // version, to ensure that unstable instances of the current version are allowed. However, if a stability
Chris@0:         // suffix is added to the constraint, then a >= match on the current version is used instead.
Chris@0:         if (preg_match('{^~>?' . $versionRegex . '$}i', $constraint, $matches)) {
Chris@0:             if (substr($constraint, 0, 2) === '~>') {
Chris@0:                 throw new \UnexpectedValueException(
Chris@0:                     'Could not parse version constraint ' . $constraint . ': ' .
Chris@0:                     'Invalid operator "~>", you probably meant to use the "~" operator'
Chris@0:                 );
Chris@0:             }
Chris@0: 
Chris@0:             // Work out which position in the version we are operating at
Chris@18:             if (isset($matches[4]) && '' !== $matches[4] && null !== $matches[4]) {
Chris@0:                 $position = 4;
Chris@18:             } elseif (isset($matches[3]) && '' !== $matches[3] && null !== $matches[3]) {
Chris@0:                 $position = 3;
Chris@18:             } elseif (isset($matches[2]) && '' !== $matches[2] && null !== $matches[2]) {
Chris@0:                 $position = 2;
Chris@0:             } else {
Chris@0:                 $position = 1;
Chris@0:             }
Chris@0: 
Chris@0:             // Calculate the stability suffix
Chris@0:             $stabilitySuffix = '';
Chris@18:             if (empty($matches[5]) && empty($matches[7])) {
Chris@0:                 $stabilitySuffix .= '-dev';
Chris@0:             }
Chris@0: 
Chris@18:             $lowVersion = $this->normalize(substr($constraint . $stabilitySuffix, 1));
Chris@0:             $lowerBound = new Constraint('>=', $lowVersion);
Chris@0: 
Chris@0:             // For upper bound, we increment the position of one more significance,
Chris@0:             // but highPosition = 0 would be illegal
Chris@0:             $highPosition = max(1, $position - 1);
Chris@0:             $highVersion = $this->manipulateVersionString($matches, $highPosition, 1) . '-dev';
Chris@0:             $upperBound = new Constraint('<', $highVersion);
Chris@0: 
Chris@0:             return array(
Chris@0:                 $lowerBound,
Chris@0:                 $upperBound,
Chris@0:             );
Chris@0:         }
Chris@0: 
Chris@0:         // Caret Range
Chris@0:         //
Chris@0:         // Allows changes that do not modify the left-most non-zero digit in the [major, minor, patch] tuple.
Chris@0:         // In other words, this allows patch and minor updates for versions 1.0.0 and above, patch updates for
Chris@0:         // versions 0.X >=0.1.0, and no updates for versions 0.0.X
Chris@0:         if (preg_match('{^\^' . $versionRegex . '($)}i', $constraint, $matches)) {
Chris@0:             // Work out which position in the version we are operating at
Chris@18:             if ('0' !== $matches[1] || '' === $matches[2] || null === $matches[2]) {
Chris@0:                 $position = 1;
Chris@18:             } elseif ('0' !== $matches[2] || '' === $matches[3] || null === $matches[3]) {
Chris@0:                 $position = 2;
Chris@0:             } else {
Chris@0:                 $position = 3;
Chris@0:             }
Chris@0: 
Chris@0:             // Calculate the stability suffix
Chris@0:             $stabilitySuffix = '';
Chris@0:             if (empty($matches[5]) && empty($matches[7])) {
Chris@0:                 $stabilitySuffix .= '-dev';
Chris@0:             }
Chris@0: 
Chris@0:             $lowVersion = $this->normalize(substr($constraint . $stabilitySuffix, 1));
Chris@0:             $lowerBound = new Constraint('>=', $lowVersion);
Chris@0: 
Chris@0:             // For upper bound, we increment the position of one more significance,
Chris@0:             // but highPosition = 0 would be illegal
Chris@0:             $highVersion = $this->manipulateVersionString($matches, $position, 1) . '-dev';
Chris@0:             $upperBound = new Constraint('<', $highVersion);
Chris@0: 
Chris@0:             return array(
Chris@0:                 $lowerBound,
Chris@0:                 $upperBound,
Chris@0:             );
Chris@0:         }
Chris@0: 
Chris@0:         // X Range
Chris@0:         //
Chris@0:         // Any of X, x, or * may be used to "stand in" for one of the numeric values in the [major, minor, patch] tuple.
Chris@0:         // A partial version range is treated as an X-Range, so the special character is in fact optional.
Chris@0:         if (preg_match('{^v?(\d++)(?:\.(\d++))?(?:\.(\d++))?(?:\.[xX*])++$}', $constraint, $matches)) {
Chris@18:             if (isset($matches[3]) && '' !== $matches[3] && null !== $matches[3]) {
Chris@0:                 $position = 3;
Chris@18:             } elseif (isset($matches[2]) && '' !== $matches[2] && null !== $matches[2]) {
Chris@0:                 $position = 2;
Chris@0:             } else {
Chris@0:                 $position = 1;
Chris@0:             }
Chris@0: 
Chris@0:             $lowVersion = $this->manipulateVersionString($matches, $position) . '-dev';
Chris@0:             $highVersion = $this->manipulateVersionString($matches, $position, 1) . '-dev';
Chris@0: 
Chris@0:             if ($lowVersion === '0.0.0.0-dev') {
Chris@0:                 return array(new Constraint('<', $highVersion));
Chris@0:             }
Chris@0: 
Chris@0:             return array(
Chris@0:                 new Constraint('>=', $lowVersion),
Chris@0:                 new Constraint('<', $highVersion),
Chris@0:             );
Chris@0:         }
Chris@0: 
Chris@0:         // Hyphen Range
Chris@0:         //
Chris@0:         // Specifies an inclusive set. If a partial version is provided as the first version in the inclusive range,
Chris@0:         // then the missing pieces are replaced with zeroes. If a partial version is provided as the second version in
Chris@0:         // the inclusive range, then all versions that start with the supplied parts of the tuple are accepted, but
Chris@0:         // nothing that would be greater than the provided tuple parts.
Chris@0:         if (preg_match('{^(?P<from>' . $versionRegex . ') +- +(?P<to>' . $versionRegex . ')($)}i', $constraint, $matches)) {
Chris@0:             // Calculate the stability suffix
Chris@0:             $lowStabilitySuffix = '';
Chris@0:             if (empty($matches[6]) && empty($matches[8])) {
Chris@0:                 $lowStabilitySuffix = '-dev';
Chris@0:             }
Chris@0: 
Chris@0:             $lowVersion = $this->normalize($matches['from']);
Chris@0:             $lowerBound = new Constraint('>=', $lowVersion . $lowStabilitySuffix);
Chris@0: 
Chris@0:             $empty = function ($x) {
Chris@0:                 return ($x === 0 || $x === '0') ? false : empty($x);
Chris@0:             };
Chris@0: 
Chris@0:             if ((!$empty($matches[11]) && !$empty($matches[12])) || !empty($matches[14]) || !empty($matches[16])) {
Chris@0:                 $highVersion = $this->normalize($matches['to']);
Chris@0:                 $upperBound = new Constraint('<=', $highVersion);
Chris@0:             } else {
Chris@0:                 $highMatch = array('', $matches[10], $matches[11], $matches[12], $matches[13]);
Chris@0:                 $highVersion = $this->manipulateVersionString($highMatch, $empty($matches[11]) ? 1 : 2, 1) . '-dev';
Chris@0:                 $upperBound = new Constraint('<', $highVersion);
Chris@0:             }
Chris@0: 
Chris@0:             return array(
Chris@0:                 $lowerBound,
Chris@0:                 $upperBound,
Chris@0:             );
Chris@0:         }
Chris@0: 
Chris@0:         // Basic Comparators
Chris@0:         if (preg_match('{^(<>|!=|>=?|<=?|==?)?\s*(.*)}', $constraint, $matches)) {
Chris@0:             try {
Chris@0:                 $version = $this->normalize($matches[2]);
Chris@0: 
Chris@0:                 if (!empty($stabilityModifier) && $this->parseStability($version) === 'stable') {
Chris@0:                     $version .= '-' . $stabilityModifier;
Chris@0:                 } elseif ('<' === $matches[1] || '>=' === $matches[1]) {
Chris@0:                     if (!preg_match('/-' . self::$modifierRegex . '$/', strtolower($matches[2]))) {
Chris@0:                         if (substr($matches[2], 0, 4) !== 'dev-') {
Chris@0:                             $version .= '-dev';
Chris@0:                         }
Chris@0:                     }
Chris@0:                 }
Chris@0: 
Chris@0:                 return array(new Constraint($matches[1] ?: '=', $version));
Chris@0:             } catch (\Exception $e) {
Chris@0:             }
Chris@0:         }
Chris@0: 
Chris@0:         $message = 'Could not parse version constraint ' . $constraint;
Chris@0:         if (isset($e)) {
Chris@0:             $message .= ': ' . $e->getMessage();
Chris@0:         }
Chris@0: 
Chris@0:         throw new \UnexpectedValueException($message);
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * Increment, decrement, or simply pad a version number.
Chris@0:      *
Chris@0:      * Support function for {@link parseConstraint()}
Chris@0:      *
Chris@0:      * @param array $matches Array with version parts in array indexes 1,2,3,4
Chris@0:      * @param int $position 1,2,3,4 - which segment of the version to increment/decrement
Chris@0:      * @param int $increment
Chris@0:      * @param string $pad The string to pad version parts after $position
Chris@0:      *
Chris@0:      * @return string The new version
Chris@0:      */
Chris@0:     private function manipulateVersionString($matches, $position, $increment = 0, $pad = '0')
Chris@0:     {
Chris@0:         for ($i = 4; $i > 0; --$i) {
Chris@0:             if ($i > $position) {
Chris@0:                 $matches[$i] = $pad;
Chris@0:             } elseif ($i === $position && $increment) {
Chris@0:                 $matches[$i] += $increment;
Chris@0:                 // If $matches[$i] was 0, carry the decrement
Chris@0:                 if ($matches[$i] < 0) {
Chris@0:                     $matches[$i] = $pad;
Chris@0:                     --$position;
Chris@0: 
Chris@0:                     // Return null on a carry overflow
Chris@0:                     if ($i === 1) {
Chris@0:                         return;
Chris@0:                     }
Chris@0:                 }
Chris@0:             }
Chris@0:         }
Chris@0: 
Chris@0:         return $matches[1] . '.' . $matches[2] . '.' . $matches[3] . '.' . $matches[4];
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * Expand shorthand stability string to long version.
Chris@0:      *
Chris@0:      * @param string $stability
Chris@0:      *
Chris@0:      * @return string
Chris@0:      */
Chris@0:     private function expandStability($stability)
Chris@0:     {
Chris@0:         $stability = strtolower($stability);
Chris@0: 
Chris@0:         switch ($stability) {
Chris@0:             case 'a':
Chris@0:                 return 'alpha';
Chris@0:             case 'b':
Chris@0:                 return 'beta';
Chris@0:             case 'p':
Chris@0:             case 'pl':
Chris@0:                 return 'patch';
Chris@0:             case 'rc':
Chris@0:                 return 'RC';
Chris@0:             default:
Chris@0:                 return $stability;
Chris@0:         }
Chris@0:     }
Chris@0: }