Haxe允许抛出一个类型的值，使用 throw 语法：
Haxe allows throwing any kind of value using its throw syntax:
throw expr 被抛出的值可以被catch块（第5.18节）捕捉。如果没有这样的块捕捉，行为取决于目标平台。
A value which is thrown like this can be caught by catch blocks (5.18). If no such block catches it, the behavior is target-dependent.