函数是一种对应规则，通过它当给定任何东西（作为参数）时，可以获得另一个东西（该参数的函数值）。

The sea is everything. It covers seven tenths of the terrestrial globe. Its breath is pure and healthy. It is an immense desert, where man is never lonely, for he feels life stirring on all sides.

The goal of computer architecture is to make the common case fast and the rare case correct.

做你自己，没有人比你更好。