为什么将#'与lambda一起使用? [英] Why use #' with lambda?

问题描述

为什么我应该在Lambda中使用#'?通常以这种方式编写，因此我认为它是一种很好的形式.但是这些行似乎和我一样:

Why should I use #' together with lambda? It is usually written that way, so I guess it is good form. But these lines seem equal to me:

> (mapcar #'(lambda (x) (+ x 1)) '(1 2 3))
(2 3 4)
> (mapcar (lambda (x) (+ x 1)) '(1 2 3))
(2 3 4)

有人介意让初学者了解两者之间的区别吗?

Anyone care to enlighten a beginner about the difference?

推荐答案

#'是function的简写，它返回指向函数的指针(而不是应用它). lambda返回一个函数，通常需要一个指向该函数的指针.由于这很常见，因此还有一个宏(在可变空间中)为您执行此操作，该宏也称为lambda.这两行代码是相同的.

#' is shorthand for function, which returns a pointer to a function (instead of applying it). lambda returns a function, and it's usual to want a pointer to that function. Since this is so common, there is also a macro (in variable space) that does it for you, which is called lambda as well. Both lines of code are identical.

哪个更好，取决于 Lisp-1/Lisp-2辩论:在宏Lisp中，您可以在Common Lisp中执行任一操作.一如既往，保持一致.

Which is better comes down to the Lisp-1/Lisp-2 debate: in Common Lisp you can do either, thanks to the macro. As always, be consistent.

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