Question

Can I do something like the following in Perl?

foreach (@tokens) {
     if (/foo/){
       # simple case, I can act on the current token alone
       # do something
       next;
    }
    if (/bar/) {
       # now I need the next token, too
       # I want to read/consume it, advancing the iterator, so that
       # the next loop iteration will not also see it
       my $nextToken = .....
       # do something
       next;
    }

}

Update: I need this in Perl, but for curiosity’s sake: Do other languages have a neat syntax for that?

Answer 1

Must you use a for loop? Copy the original and ‘consume’ it with shift:

use strict;
use warnings;

my @original = 'a' .. 'z';    # Original
my @array = @original;        # Copy

while (my $token = shift @array) {

    shift @array if $token =~ /[nr]/; # consumes the next element
    print $token;
}

# prints 'abcdefghijklmnpqrtuvwxyz' ('s' and 'o' are missing)