作者：Scott Penrose

规范：P03 - 查找列表中的第 K 个元素。列表中的第一个元素是数字 1。

示例

> say element_at <a b c d e>,3;
c

LISP

P03 (*) Find the K'th element of a list.
The first element in the list is number 1.
Example:
* (element-at '(a b c d e) 3)
C

源代码：P03-scottp.pl

use v6;

# a. One line example:
#   <> can be used to generate an array, similar to perl 5 - qw<a b c d>
#   [] is used to select the element number
#   note that the first element's index is 0, so we must subtract 1
#   say is like print to stdout with a new line
#   .say can be called as a method since everything is an object
<A B C D E F>[3 - 1].say;

# b. Subroutine example
#   @l lists can be passed in as parameters - no need to use references
#   $n a scalar location in the array
#       Note you can pass this in after an array because the array
#       is not slurped in like it would be in Perl 5 !
#   .elems - is the number of elements, this time called on the object
#   say called in procedure form
sub element_at (@l, $n) {
    return @l[$n - 1];
}
say element_at <a b c d e>,3;