protected function _code($str) {
		$self=$this;
		return preg_replace_callback(
			'/`` (.+?) ``|(?<!\\\\)`(.+?)(?!\\\\)`/',
			function($expr) use($self) {
				return '<code>'.
					$self->esc(empty($expr[1])?$expr[2]:$expr[1]).'</code>';
			},
			$str
		);
	}
protected function _code($str) {
		$self=$this;
		return preg_replace_callback(
			'/`` (.+?) ``|(?<!\\\\)`(.+?)(?!\\\\)`/',
			function($expr) use($self) {
				return '<code>'.
					$self->esc(empty($expr[1])?$expr[2]:$expr[1]).'</code>';
			},
			$str
		);
	}
protected function _code ( $ str ) { $ self = $ this ; return preg_replace_callback ( '/`` (.+?) ``|(?<!\\\\)`(.+?)(?!\\\\)`/' , function ( $ expr ) use ( $ self ) { return '<code>' . $ self -> esc ( empty ( $ expr [ 1 ] ) ? $ expr [ 2 ] : $ expr [ 1 ] ) . '</code>' ; } , $ str ) ; }
Process code span
@return string
@param $str string
Process code span