如何在Perl foreach循环中一次读取两个项目? [英] How do I read two items at a time in a Perl foreach loop?

问题描述

我正在寻找的东西是这样的:

What I'm looking for is something like:

@list = qw(1 2 3 4 5 6);
foreach (@list) {
  #perl magic goes here 
  print "i: $i, j:$j\n";
}

返回:

i:1, j:2
i:3, j:4
i:5, j:6

为响应下面的一个很好的建议，我需要指定此脚本将在其他人的构建服务器上运行，并且不允许我使用CPAN中的任何模块.仅限标准Perl.

In response to a very good suggestion below, I need to specify that this script will run on someone else's build server, and I'm not allowed to use any modules from CPAN. Standard Perl only.

推荐答案

我相信这样做的正确方法是使用natatime，来自

I believe the proper way to do this is to use natatime, from List::MoreUtils:

来自文档:

natatime阻止列表

natatime BLOCK LIST

创建一个数组迭代器，用于循环遍历$n个项目的大块数组 一次. (一次n，明白吗?).一个例子可能更好 比我无法用言语表达的解释.

Creates an array iterator, for looping over an array in chunks of $n items at a time. (n at a time, get it?). An example is probably a better explanation than I could give in words.

示例:

 my @x = ('a' .. 'g');
 my $it = natatime 3, @x;
 while (my @vals = $it->())
 {
     print "@vals\n";
 }

此打印

a b c
d e f
g

List::MoreUtils::natatime :

sub natatime ($@)
{
    my $n = shift;
    my @list = @_;

    return sub
    {
        return splice @list, 0, $n;
    }
}

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