so/as long as用作连词通常表达两种意思：

1.相当于if或provided that“如果；只要”，用以引导条件状语从句。如：

You can go out, as long as you promise to be back before eleven o'clock.如果你答应11点钟以前回来，你就可以出去。《英语惯用短语词典》

2.相当于since，because，或considering that“既然；因为；由于”，用以引导原因状语从句。如：

As long as we've driven this far，we might as well go on．既然我们已经驶得这么远了，就不妨继续往前驶。《英语常用短语词典》