将列表评估为Clojure的出租对象 [英] eval a list into a let on clojure

问题描述

下一个是我的问题，我尝试使用let将值分配给这些变量来评估包含一些变量的列表

My problem is the next, i try to evaluate a list with some vars using a let to asign values to this vars

如果我做(def a (list * 'x 'y))和(let [x 3 y 3] (eval a))，我有一个 CompilerException java.lang.RuntimeException:无法解析符号:x在这种情况下，编译:(NO_SOURCE_PATH:6)

if i do (def a (list * 'x 'y)) and (let [x 3 y 3] (eval a)) I have a CompilerException java.lang.RuntimeException: Unable to resolve symbol: x in this context, compiling:(NO_SOURCE_PATH:6)

但是如果我跑步 (def x 4) (def y 4)和(eval a)我有16，反正如果我再次运行(let [x 3 y 3] (eval a))我有16，

but if I run (def x 4) (def y 4) and (eval a) i have a 16, anyway if I run again (let [x 3 y 3] (eval a)) again I have 16,

是否存在正确绑定x和y并评估列表的方法?

exist a method to binding the x and y correctly and eval the list?

ty！

推荐答案

好吧，您还可以eval let表达式，看看这是否是您需要的:

Well, you could also eval the let expression, See if this is what you need:

(eval '(let [x 3 y 3] (* x y)))

根据评论，这将适合您的情况:

According to the comments, this will work for your case:

(def a (list (list * 'x 'y)))
(eval (concat '(let [x 3 y 3]) a))

更好的是，使用准引用:

Even better, use quasiquoting:

(def a (list * 'x 'y))
(eval `(let ~'[x 3 y 3] ~a))

这篇关于将列表评估为Clojure的出租对象的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！