结合predicates在F＃ [英] Combining Predicates in F#

问题描述

是否有逻辑地组合predicates在F＃中一个标准的方式？ 举例来说，假设我有 ISCAR X 和 isBlue X 然后我想要的东西，给我：

Is there a standard way of logically combining predicates in F#? For example, let's say I have isCar x and isBlue x then I want something that gives me:

let isBlueCar x = isCar x && isBlue x

但在使用某种形式的成分，而不是调用，也许这样的：

But using some sort of composition, rather than invocation, maybe like:

let isBlueCar x = isCar && isBlue

preferably，这东西大概能接受predicates大/任意数量。

Preferably, that something would be able to accept a large/arbitrary number of predicates.

推荐答案

您可以定义一个组合子。

You could define a combinator.

let (<&>) f g = (fun x -> f x && g x)

然后执行

let isBlueCar = isCar <&> isBlue

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