字符串名称中的clojure解析函数 [英] clojure resolving function from string name

问题描述

在clojure 1.2RC1中，我希望基于其名称作为字符串来获取一个函数并对其进行评估.

In clojure 1.2RC1, I wish to obtain a function based on its name as string and evaluate it.

函数定义

(ns my-ns)

(defn mycar [x] (first x))

以下工作有效:

((ns-resolve *ns* (symbol "mycar")) '(3 4))
((intern *ns* (symbol "mycar")) '(3 4))
((eval (symbol "mycar")) '(3  4))

但是它们看起来很丑.有没有更好的办法?如果不是，那么以上哪个是最惯用的?

but they seem ugly. Is there a better way? If not, which of the above is the most idiomatic?

推荐答案

这对我有效，无需使用eval:

This worked for me without using eval:

user> (defn mycar [x] (first x))
#'user/mycar
user> ((resolve (symbol "mycar")) [1 2 3])
1

之所以可行，是因为resolves在当前名称空间中找到了mycar var，并且var调用了它所绑定的函数.这是第一个示例的简短版本.我只是为了避免使用eval而使用它.

This works because resolves finds the mycar var in the current namespace and the var calls the function it's bound to. This is a shorter version of your first example. I'd use it just so that I could avoid using eval.

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