如何在Scheme中的列表中使用lambdas(How to use lambdas from a list in Scheme)

 我在查找如何使用Scheme中列表中包含的lambda时遇到了一些麻烦。 例如，我有以下代码： 
 
(define abc '((lambda (x) (* x x))))
 
 我想从列表中取出第一个lambda并将其应用于某些数字。 这是我到目前为止： 
 
(map (car abc) '(1 2 3))
 
 但是，我收到以下错误： 
 
;The object (lambda (x) (* x x)) is not applicable.
 
 但是当我直接使用lambda尝试相同的东西时，它的工作原理是： 
 
(map (lambda (x) (* x x)) '(1 2 3))
;Value 15: (1 4 9)
 
 有人能帮我理解我做错了吗？ 

I'm having some trouble figuring out how to use lambdas that are contained within lists in Scheme. For example, I have the following code:
 
(define abc '((lambda (x) (* x x))))
 
I would like to take the first lambda from the list and apply it to some numbers. Here is what I have so far:
 
(map (car abc) '(1 2 3))
 
However, I get the following error:
 
;The object (lambda (x) (* x x)) is not applicable.
 
But when I try the same thing directly using just the lambda, it works:
 
(map (lambda (x) (* x x)) '(1 2 3))
;Value 15: (1 4 9)
 
Can someone help me understand what I am doing wrong?

原文：https://stackoverflow.com/questions/36808259