src/Debug/Output/Html.php
protected function visualWhiteSpace($str)
    {
        // display \r, \n, & \t
        $str = \preg_replace_callback('/(\r\n|\r|\n)/', array($this, 'visualWhiteSpaceCallback'), $str);
        $str = \preg_replace('#(<br />)?\n$#', '', $str);
        $str = \str_replace("\t", '<span class="ws_t">'."\t".'</span>', $str);
        return $str;
    }
protected function visualWhiteSpace($str)
    {
        // display \r, \n, & \t
        $str = \preg_replace_callback('/(\r\n|\r|\n)/', array($this, 'visualWhiteSpaceCallback'), $str);
        $str = \preg_replace('#(<br />)?\n$#', '', $str);
        $str = \str_replace("\t", '<span class="ws_t">'."\t".'</span>', $str);
        return $str;
    }
protected function visualWhiteSpace ( $ str ) { // display \r, \n, & \t $ str = \ preg_replace_callback ( '/(\r\n|\r|\n)/' , array ( $ this , 'visualWhiteSpaceCallback' ) , $ str ) ; $ str = \ preg_replace ( '#(<br />)?\n$#' , '' , $ str ) ; $ str = \ str_replace ( "\t" , '<span class="ws_t">' . "\t" . '</span>' , $ str ) ; return $ str ; }
Add whitespace markup

@param string $str string which to add whitespace html markup

@return string
Add whitespace markup