perl的语法一向古怪，约定的东西太多了
比如昨晚看Advanced Perl Programming，第一章讲引用，举了这个例子
$s = \('a', 'b', 'c');
猜一下$s指向什么?
As it happens, this is identical to
$s = (\'a', \'b', \'c'); # List of references to scalarsBeginners often make the mistake of confusing array variables and enumerated (comma-separated) lists.
