测试是否阵列在口齿不清名单内

问题描述

我有两个项目。第一， A-子，是含有数组作为它的第一个元素，然后一些字符串作为剩余单元的明细表。另外，映射，是它包含了一些阵列的列表。通过观察，可以很容易地看到， A-子是映射，虽然我不能找到一个函数会发现它适合我。

I have two items. The first, a-child, is a list which contains an array as its first element and then some strings as the remaining elements. The other, mapped, is a list which contains a number of arrays. By inspection, it's easy to see that a-child is in mapped, though I can't find a function which will find it for me.

我下面穷人口齿不清的风格道歉 - 我开始前几天，所以我没有拿起所有的公约尚未

I apologize for the poor lisp style below - I started a few days ago, so I haven't picked up all the conventions yet.

(defparameter a-child (list (#2A((1 2 3) (7 4 5) (9 8 6))) "U" "R" "R"))
(defparameter mapped (list (#2A((1 2 3) (7 4 5) (9 8 6))) (#2A((1 2 3) (4 5 6) (7 8 9)))))
(find (car a-child) mapped)   ;;returns NIL
(member (car a-child) mapped) ;;returns NIL
(position (car a-child) mapped) ;;returns NIL
(equalp (car a-child) (car mapped)) ;;returns T

什么功能，我可以使用来寻找阵列的列表内的数组？谢谢你。

What function can I use to look for arrays within a list of arrays?? Thank you.

推荐答案

您的序列函数标有返回NIL将返回 T 如果您通过：测试＃'equalp 他们

The Answer

Your sequence functions marked "returns NIL" will return T if you pass :test #'equalp to them.

Common Lisp中的默认是 EQL 。

The default Two-Argument Test in Common Lisp is eql.

这是4之间最合理的选择由ANSI标准CL提供通用的比较函数（！）：

It is the most reasonable choice between the 4(!) general purpose comparison functions provided for by the ANSI CL standard:

• 是太依赖于实现，并为一个可能想要在数字和字符不起作用

• eq is too implementation-dependent and does not work as one probably wants on numbers and characters

和遍历对象，从而需要很长时间的巨大的人，也许永远不会终止循环的。

equal and equalp traverse objects and thus take long time for huge ones and may never terminate for circular ones.

又见the EQ，EQL，平等，equalp Common Lisp中之间的区别。

这篇关于测试是否阵列在口齿不清名单内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！