测试是否阵列在口齿不清名单内 [英] Test if array is inside a list in lisp

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中的默认两个参数的测试是<一个HREF =htt​​p://www.lispworks.com/documentation/HyperSpec/Body/f_eql.htm相对=nofollow> 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:

• EQ 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

等于 和 equalp 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<一个href=\"http://stackoverflow.com/questions/547436/whats-the-difference-between-eq-eql-equal-and-equalp-in-common-lisp\">the EQ，EQL，平等，equalp Common Lisp中之间的区别。

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