Siesvi -- PHP CSV Parser

<?php
class Siesvi implements Iterator {
    const FETCH_NUM = 1; // fetch NUM instead of ASSOC (auto ON if NOT_HAVE_HEADER)
    const FETCH_OBJECT = 2; // fetch OBJECT instead of ARRAY
    const NOT_HAVE_HEADER = 4; // first row is DATA instead of HEADER
    public $fname;
    public $mode;
    // mode = 0; fetch array assoc, first row on the file is header
    // mode = 1; fetch array num, first row on the file is header
    // mode = 2; fetch object assoc, first row on the file is header
    // mode = 3; fetch object num, first row on the file is header
    // mode = 4,5; fetch array num, first row on the file is data
    // mode = 6,7; fetch object num, first row on the file is data
    private $fh;
    public $pos;
    public $row;
    public $headers;
    public function __construct( $fname, $mode = 0 ) {
        $this->fname = $fname;
        $this->mode = $mode;
    }
    public function rewind() {
        if ( $this->fh )
            fclose( $this->fh );
        $this->fh = fopen( $this->fname, 'r' );
        $this->headers = array();
        if ( !( $this->mode & Siesvi::NOT_HAVE_HEADER ) ){
            $this->next();
            if ( $this->valid() )
                $this->headers = $this->row;
        }
        $this->pos = -1;
        $this->next();
    }
    public function key() {
        return $this->pos;
    }
    public function current() {
        if ( $this->mode & Siesvi::FETCH_NUM || ! $this->headers ){
            if ( $this->mode & Siesvi::FETCH_OBJECT )
                return (object) $this->row;
            return $this->row;
        } else {
            if ( $this->mode & Siesvi::FETCH_OBJECT )
                return (object) array_combine( $this->headers, $this->row );
            return array_combine( $this->headers, $this->row );
        }
    }
    public function next() {
        ++$this->pos;
        $str = fgets( $this->fh );
        if ( $str === false ){
            fclose( $this->fh );
            $this->fh = false;
            return;
        }
        $quote = 0;
        $cell = "";
        $this->row = array();
        for ( $i = 0, $strlen = strlen( $str ); $i < $strlen; $i++ ){
            $chr = $str[$i];
            if ( $quote == 0 && $chr == "," ){
                $this->row[] = $cell;
                $cell = "";
            } elseif ( $quote == 0 && $chr == '"' ){
                $quote = 1;
            } elseif ( $quote == 1 && $chr == '"' ){
                if ( $str[ $i + 1 ] == '"' )
                    $cell .= $chr;
                $quote = 0;
            } elseif ( $quote == 1 && $chr == "\n" ){
                $cell .= $chr;
                $str .= fgets( $this->fh );
                $strlen = strlen( $str );
            } elseif ( $quote == 1 || ( $chr != "\r" && $chr != "\n" )) {
                $cell .= $chr;
            }
        }
        $this->row[] = $cell;
    }
    public function valid() {
        return $this->fh;
    }
}
/*
file_put_contents( __DIR__ . "/test.csv", <<<'EOD'
id,"name",price,"notes"
1,"kucing ""kampung""",1000,"""Suaranya"" ""meong""
""meong"""
2,ayam", "dilepeh"""",2000,"Suaranya sreng-sreng, tadinya, pas digoreng.."
EOD
);


$csv = new Siesvi( __DIR__ . "/test.csv" );
foreach ( range(0,7) as $mode ){
    $csv->mode = $mode;
    echo sprintf( "MODE = %s\r\n", $mode );
    foreach( $csv as $k => $v) {
        echo sprintf( "Data ke-%s\r\n", $k );
        print_r( $v );
        echo "\r\n";
    }
    echo "----\r\n";
}
*/