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

natatime在XS中实现,因此您应该更喜欢它以提高效率.仅用于说明目的,以下是如何在Perl中实现三元素迭代器生成器：

#!/usr/bin/perl

use strict; use warnings;

my @v = ('a' .. 'z' );

my $it = make_3it(\@v);

while ( my @tuple = $it->() ) {
    print "@tuple\n";
}

sub make_3it {
    my ($arr) = @_;
    {
        my $lower = 0;
        return sub {
            return unless $lower < @$arr;
            my $upper = $lower + 2;
            @$arr > $upper or $upper = $#$arr;
            my @ret = @$arr[$lower .. $upper];
            $lower = $upper + 1;
            return @ret;
        }
    }
}