Simple php csv reader

CsvReader.php

<?php 
/**
 * @author nimmneun
 * @since 27.06.2015 06:05
 */
class CsvReader
{
    /**
     * The single line strings.
     * @var array
     */
    private $lines;

    /**
     * Character to seperate data within a line.
     * @var string
     */
    private $delimiter;

    /**
     * Character enclosing data.
     * @var string
     */
    private $enclose;

    /**
     * The current line number.
     * @var int
     */
    public $line;

    /**
     * Load the string and split by line breaks.
     * Set delimiter and enclosing character.
     * @param string $string
     * @param string $delimiter
     * @param string $enclose
     * @return CsvReader
     */
    static function load($string = null, $delimiter = ';', $enclose = '')
    {
        $object = new self;
        $object->delimiter = $delimiter;
        $object->enclose = $enclose;
        $object->stringToLines($string);

        return $object;
    }

    /**
     * Data from next single line.
     * @return array|false
     */
    public function next()
    {
        $this->line = null === $this->line ? 1 : $this->line+1;

        return $this->lineToRow();
    }

    /**
     * Data from previous single line.
     * @return array|false
     */
    public function prev()
    {
        $this->line = (null||1) === $this->line ? 1 : $this->line-1;

        return $this->lineToRow();
    }

    /**
     * Set the current $line to [n].
     * @param int $offset
     */
    public function offset($offset)
    {
        $this->line += $offset;
    }

    /**
     * Rewind back to first line.
     */
    public function rewind()
    {
        $this->line = null;
    }

    /**
     * Split initial input by linebreak. Should work for Linux, Mac & Win.
     * @param string $string
     */
    private function stringToLines($string)
    {
        $this->lines = preg_split('/[\r\n]{1,2}/', rtrim($string));
        $this->lines = array_map('rtrim', $this->lines);
    }

    /**
     * Split the current line by delimiter and optional enclosing string.
     * e.g. ["some funny string";"another one";"a "cool" string"] should be fine
     * with $delimiter [;] and $enclose ["]
     *
     * @return array|false
     */
    private function lineToRow()
    {
        if (isset($this->lines[$this->line-1]))
        {
            $line = substr(
                $this->lines[$this->line-1],
                strlen($this->enclose),
                strlen($this->lines[$this->line-1])-strlen($this->enclose)*2
            );

            $row = preg_split("/".$this->enclose.$this->delimiter.$this->enclose."/", $line);
        }
        else
        {
            $row = false;
        }

        return $row;
    }
}