diff options
Diffstat (limited to 'NXP/Classes/TokenParser.php')
| -rw-r--r-- | NXP/Classes/TokenParser.php | 159 |
1 files changed, 0 insertions, 159 deletions
diff --git a/NXP/Classes/TokenParser.php b/NXP/Classes/TokenParser.php deleted file mode 100644 index 7b9255f..0000000 --- a/NXP/Classes/TokenParser.php +++ /dev/null @@ -1,159 +0,0 @@ -<?php -/** - * Author: Alexander "NeonXP" Kiryukhin - * Date: 17.03.13 - * Time: 2:45 - */ - -namespace NXP\Classes; - - -class TokenParser { - const DIGIT = 'DIGIT'; - const CHAR = 'CHAR'; - const SPECIAL_CHAR = 'SPECIAL_CHAR'; - const LEFT_BRACKET = 'LEFT_BRACKET'; - const RIGHT_BRACKET = 'RIGHT_BRACKET'; - const SPACE = 'SPACE'; - - private $terms = [ - self::DIGIT => '[0-9\.]', - self::CHAR => '[a-z]', - self::SPECIAL_CHAR => '[\!\@\#\$\%\^\&\*\/\|\-\+\=\~]', - self::LEFT_BRACKET => '\(', - self::RIGHT_BRACKET => '\)', - self::SPACE => '\s' - ]; - - const ERROR_STATE = 'ERROR_STATE'; - - private $transitions = [ - Token::NOTHING => [ - self::DIGIT => Token::NUMBER, - self::CHAR => Token::STRING, - self::SPECIAL_CHAR => Token::OPERATOR, - self::LEFT_BRACKET => Token::LEFT_BRACKET, - self::RIGHT_BRACKET => Token::RIGHT_BRACKET, - self::SPACE => Token::NOTHING - ], - Token::STRING => [ - self::DIGIT => Token::STRING, - self::CHAR => Token::STRING, - self::SPECIAL_CHAR => Token::OPERATOR, - self::LEFT_BRACKET => Token::LEFT_BRACKET, - self::RIGHT_BRACKET => Token::RIGHT_BRACKET, - self::SPACE => Token::NOTHING - ], - Token::NUMBER => [ - self::DIGIT => Token::NUMBER, - self::CHAR => self::ERROR_STATE, - self::SPECIAL_CHAR => Token::OPERATOR, - self::LEFT_BRACKET => Token::LEFT_BRACKET, - self::RIGHT_BRACKET => Token::RIGHT_BRACKET, - self::SPACE => Token::NOTHING - ], - Token::OPERATOR => [ - self::DIGIT => Token::NUMBER, - self::CHAR => Token::STRING, - self::SPECIAL_CHAR => Token::OPERATOR, - self::LEFT_BRACKET => Token::LEFT_BRACKET, - self::RIGHT_BRACKET => Token::RIGHT_BRACKET, - self::SPACE => Token::NOTHING - ], - self::ERROR_STATE => [ - self::DIGIT => self::ERROR_STATE, - self::CHAR => self::ERROR_STATE, - self::SPECIAL_CHAR => self::ERROR_STATE, - self::LEFT_BRACKET => self::ERROR_STATE, - self::RIGHT_BRACKET => self::ERROR_STATE, - self::SPACE => self::ERROR_STATE - ], - Token::LEFT_BRACKET => [ - self::DIGIT => Token::NUMBER, - self::CHAR => Token::STRING, - self::SPECIAL_CHAR => Token::OPERATOR, - self::LEFT_BRACKET => Token::LEFT_BRACKET, - self::RIGHT_BRACKET => Token::RIGHT_BRACKET, - self::SPACE => Token::NOTHING - ], - Token::RIGHT_BRACKET => [ - self::DIGIT => Token::NUMBER, - self::CHAR => Token::STRING, - self::SPECIAL_CHAR => Token::OPERATOR, - self::LEFT_BRACKET => Token::LEFT_BRACKET, - self::RIGHT_BRACKET => Token::RIGHT_BRACKET, - self::SPACE => Token::NOTHING - ], - ]; - - private $accumulator = ''; - - private $state = Token::NOTHING; - - private $queue = null; - - function __construct() - { - $this->queue = new \SplQueue(); - } - - /** - * Tokenize math expression - * @param $expression - * @return \SplQueue - * @throws \Exception - */ - public function tokenize($expression) - { - $oldState = null; - for ($i=0; $i<strlen($expression); $i++) { - $char = substr($expression, $i, 1); - $class = $this->getSymbolType($char); - $oldState = $this->state; - $this->state = $this->transitions[$this->state][$class]; - if ($this->state == self::ERROR_STATE) { - throw new \Exception("Parse expression error at $i column (symbol '$char')"); - } - $this->addToQueue($oldState); - $this->accumulator .= $char; - } - if (!empty($this->accumulator)) { - $token = new Token($this->state, $this->accumulator); - $this->queue->push($token); - } - - return $this->queue; - } - - /** - * @param $symbol - * @return string - * @throws \Exception - */ - private function getSymbolType($symbol) - { - foreach ($this->terms as $class => $regex) { - if (preg_match("/$regex/i", $symbol)) { - return $class; - } - } - - throw new \Exception("Unknown char '$symbol'"); - } - - /** - * @param $oldState - */ - private function addToQueue($oldState) - { - if ($oldState == Token::NOTHING) { - $this->accumulator = ''; - return; - } - if (($this->state != $oldState) || ($oldState == Token::LEFT_BRACKET) || ($oldState == Token::RIGHT_BRACKET)) { - $token = new Token($oldState, $this->accumulator); - $this->queue->push($token); - $this->accumulator = ''; - } - } -}
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