可以流动注释无点函数吗？

Question

Given these types: 鉴于以下类型：

type Bar = number;
type Foo = {
  bar: Bar,
};

And this point-free conversion function fooToBar : 而这个无点转换函数fooToBar ：

import { prop } from 'ramda';
const fooToBar = prop('bar');

Is it possible to annotate fooToBar 's signature of Foo -> Bar ? 是否可以注释fooToBar的Foo -> Bar签名Foo -> Bar ？

Answer 1

The function type annotation docs are pretty detailed. 函数类型注释文档非常详细。 It looks like the following should work for you 看起来以下内容适合您

/* @flow */

type Bar = number;
type Foo = {
  bar: Bar,
};

const prop = y => x => x[y];

const fooToBar : Foo => Bar = prop('bar');

No errors!