flowtype - 为什么 Flow 需要标注导出函数的参数？

Question

以下代码( Flow playground ):

/* @flow */

function a(p) {}
module.exports = a

抛出异常

3: function a(p) {}
              ^ parameter `p`. Missing annotation

这是为什么？我希望那种类型 any将自动假定参数 p .

Answer 1

来自 documentation :

Module Boundaries

Flow requires annotations at the boundaries of modules. This allows Flow to analyze modules in isolation which improves the performance of checking types across module boundaries. We’ve found that this helps to improve the self-documenting nature of module interfaces as well.