iamchenxin
nmn
/ FunctionValue.ts
Last active
November 3, 2017 12:25
Magic Flow Type 1: $FunctionXValue —— A magic flow type that takes a function type that takes one arg, the type of that arg, and returns the return value type of the function.
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| /* @flow */ | |
| type $Function1<A, B> = (arg: A) => B; | |
| type _Function1Value<A, B, F: $Function1<A, B>> = B; // eslint-disable-line | |
| type $Function1Value<F: $Function1<*, *>, A> = _Function1Value<A, *, F>; | |
| var toString = (value) => String(value) | |
| var toNumber = (value) => parseFloat(value) || 0 | |
| type NumberXString = ((value: number) => string) & ((value: string) => number) |