将函数序列应用于值序列 [英] Applying sequence of functions to a sequence of values
问题描述
我想成对地将函数列表应用于值列表.
I want to pairwise apply a list of functions to a list of values.
这里有一个例子来说明.
Here's an example to illustrate.
user=> (defn a [f x] (f x))
#'user/a
user=> (map a [inc dec] '(98 8))
(99 7)
注意我必须定义一个函数 a ,它接受一个函数并将其应用于一个值.基本上是抽象函数应用.
Notice I had to define a function a that takes a function and applies it to a value. Basically abstracting function application.
有没有更自然的方法来做到这一点?我真的很想使用 map 来定义一个辅助函数.
Is there a more natural way to do this? I would really just like to use map with defining a helper function.
推荐答案
你总是可以匿名定义函数,内联:
You can always define functions anonymously, inline:
(map (fn [f x] (f x)) [inc dec] '(98 8))
或更短,使用#() 阅读器宏:
or shorter, using the #() reader macro:
(map #(%1 %2) [inc dec] '(98 8))
尽管这是一个相当尴尬的用例,所以我怀疑您是否可以仅使用核心 clojure 或 clojure.contrib 将其缩短为更短的内容,但您可以轻松编写自己的抽象:
It's a fairly awkward use case though, so I doubt you can reduce it to something shorter using just core clojure or clojure.contrib, but you can easily write your own abstraction:
(defn mapfs [fs coll] (map #(%1 %2) fs coll))
(mapfs [inc dec] [98 8])
> (99 7)
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