SqlParser\Components\SetOperation::parse PHP Method

    public static function parse(Parser $parser, TokensList $list, array $options = array())
    {
        $ret = array();
        $expr = new SetOperation();
        /**
         * The state of the parser.
         *
         * Below are the states of the parser.
         *
         *      0 -------------------[ column name ]-------------------> 1
         *
         *      1 ------------------------[ , ]------------------------> 0
         *      1 ----------------------[ value ]----------------------> 1
         *
         * @var int $state
         */
        $state = 0;
        for (; $list->idx < $list->count; ++$list->idx) {
            /**
             * Token parsed at this moment.
             *
             * @var Token $token
             */
            $token = $list->tokens[$list->idx];
            // End of statement.
            if ($token->type === Token::TYPE_DELIMITER) {
                break;
            }
            // Skipping whitespaces and comments.
            if ($token->type === Token::TYPE_WHITESPACE || $token->type === Token::TYPE_COMMENT) {
                continue;
            }
            // No keyword is expected.
            if ($token->type === Token::TYPE_KEYWORD && $token->flags & Token::FLAG_KEYWORD_RESERVED && $state == 0) {
                break;
            }
            if ($state === 0) {
                if ($token->token === '=') {
                    $state = 1;
                } elseif ($token->value !== ',') {
                    $expr->column .= $token->token;
                }
            } elseif ($state === 1) {
                $tmp = Expression::parse($parser, $list, array('breakOnAlias' => true));
                if ($tmp == null) {
                    break;
                }
                $expr->column = trim($expr->column);
                $expr->value = $tmp->expr;
                $ret[] = $expr;
                $expr = new SetOperation();
                $state = 0;
            }
        }
        --$list->idx;
        return $ret;
    }

 /**
  * @param Parser     $parser The instance that requests parsing.
  * @param TokensList $list   The list of tokens to be parsed.
  *
  * @return void
  */
 public function parse(Parser $parser, TokensList $list)
 {
     ++$list->idx;
     // Skipping `INSERT`.
     // parse any options if provided
     $this->options = OptionsArray::parse($parser, $list, static::$OPTIONS);
     ++$list->idx;
     $token = $list->tokens[$list->idx];
     /**
      * The state of the parser.
      *
      * Below are the states of the parser.
      *
      *      0 ---------------------------------[ INTO ]----------------------------------> 1
      *
      *      1 -------------------------[ VALUES/VALUE/SET/SELECT ]-----------------------> 2
      *
      *      2 -------------------------[ ON DUPLICATE KEY UPDATE ]-----------------------> 3
      *
      * @var int $state
      */
     $state = 0;
     /**
      * For keeping track of semi-states on encountering
      * ON DUPLICATE KEY UPDATE ...
      *
      */
     $miniState = 0;
     for (; $list->idx < $list->count; ++$list->idx) {
         /**
          * Token parsed at this moment.
          *
          * @var Token $token
          */
         $token = $list->tokens[$list->idx];
         // End of statement.
         if ($token->type === Token::TYPE_DELIMITER) {
             break;
         }
         // Skipping whitespaces and comments.
         if ($token->type === Token::TYPE_WHITESPACE || $token->type === Token::TYPE_COMMENT) {
             continue;
         }
         if ($state === 0) {
             if ($token->type === Token::TYPE_KEYWORD && $token->value !== 'INTO') {
                 $parser->error(__('Unexpected keyword.'), $token);
                 break;
             } else {
                 ++$list->idx;
                 $this->into = IntoKeyword::parse($parser, $list);
             }
             $state = 1;
         } elseif ($state === 1) {
             if ($token->type === Token::TYPE_KEYWORD) {
                 if ($token->value === 'VALUE' || $token->value === 'VALUES') {
                     ++$list->idx;
                     // skip VALUES
                     $this->values = Array2d::parse($parser, $list);
                 } elseif ($token->value === 'SET') {
                     ++$list->idx;
                     // skip SET
                     $this->set = SetOperation::parse($parser, $list);
                 } elseif ($token->value === 'SELECT') {
                     $this->select = new SelectStatement($parser, $list);
                 } else {
                     $parser->error(__('Unexpected keyword.'), $token);
                     break;
                 }
                 $state = 2;
                 $miniState = 1;
             } else {
                 $parser->error(__('Unexpected token.'), $token);
                 break;
             }
         } elseif ($state == 2) {
             $lastCount = $miniState;
             if ($miniState === 1 && $token->value === 'ON') {
                 $miniState++;
             } elseif ($miniState === 2 && $token->value === 'DUPLICATE') {
                 $miniState++;
             } elseif ($miniState === 3 && $token->value === 'KEY') {
                 $miniState++;
             } elseif ($miniState === 4 && $token->value === 'UPDATE') {
                 $miniState++;
             }
             if ($lastCount === $miniState) {
                 $parser->error(__('Unexpected token.'), $token);
                 break;
             }
             if ($miniState === 5) {
                 ++$list->idx;
                 $this->onDuplicateSet = SetOperation::parse($parser, $list);
                 $state = 3;
             }
         }
     }
     --$list->idx;
 }