SqlParser\Components\RenameOperation::parse PHP Метод

    public static function parse(Parser $parser, TokensList $list, array $options = array())
    {
        $ret = array();
        $expr = new RenameOperation();
        /**
         * The state of the parser.
         *
         * Below are the states of the parser.
         *
         *      0 ---------------------[ old name ]--------------------> 1
         *
         *      1 ------------------------[ TO ]-----------------------> 2
         *
         *      2 ---------------------[ old name ]--------------------> 3
         *
         *      3 ------------------------[ , ]------------------------> 0
         *      3 -----------------------[ else ]----------------------> (END)
         *
         * @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 || $token->type === Token::TYPE_COMMENT) {
                continue;
            }
            if ($state === 0) {
                $expr->old = Expression::parse($parser, $list, array('breakOnAlias' => true, 'parseField' => 'table'));
                if (empty($expr->old)) {
                    $parser->error(__('The old name of the table was expected.'), $token);
                }
                $state = 1;
            } elseif ($state === 1) {
                if ($token->type === Token::TYPE_KEYWORD && $token->value === 'TO') {
                    $state = 2;
                } else {
                    $parser->error(__('Keyword "TO" was expected.'), $token);
                    break;
                }
            } elseif ($state === 2) {
                $expr->new = Expression::parse($parser, $list, array('breakOnAlias' => true, 'parseField' => 'table'));
                if (empty($expr->new)) {
                    $parser->error(__('The new name of the table was expected.'), $token);
                }
                $state = 3;
            } elseif ($state === 3) {
                if ($token->type === Token::TYPE_OPERATOR && $token->value === ',') {
                    $ret[] = $expr;
                    $expr = new RenameOperation();
                    $state = 0;
                } else {
                    break;
                }
            }
        }
        if ($state !== 3) {
            $parser->error(__('A rename operation was expected.'), $list->tokens[$list->idx - 1]);
        }
        // Last iteration was not saved.
        if (!empty($expr->old)) {
            $ret[] = $expr;
        }
        --$list->idx;
        return $ret;
    }

 public function testBuild()
 {
     $component = RenameOperation::parse(new Parser(), $this->getTokensList('a TO b, c TO d'));
     $this->assertEquals(RenameOperation::build($component), 'a TO b, c TO d');
 }