Re: Using Number Ranges in a Dispatch Table

[RichardK]

I think using given Switch statements gives you much more flexibility, as it uses smart matching and can do lots of clever things. You do have to type a bit more but it's worth it ;)

So something like this :-

use v5.14;
use warnings;


sub ident_number {
  my ($num) = @_;

  given ($num) {
    when ('01') {
      say 'geographic';
    }

    when (/^\d+$/ && $_ >= 124 && $_ <= 140) {
      say '124 - 140';
    }
    when ([143 .. 146, 148 .. 149]) {
      say "$_ other stuff";
    }

    when ([181 ..189]) {
      say '181 -- 189';
    }
    default {
      say "$_ not found";
    }
  }
}


my @tests = qw/ 01 02 125 127 186 500 143 149 189/;

for (@tests) {
  ident_number($_);
}

[tobyink]

My initial attempt was based on given but I switched to using a list of smart matches and subroutines because given has a drawback compared to dispatch tables...

With dispatch tables you can check whether a particular value can dispatch, without actually doing the dispatching yet. If your dispatch table is a hash, then it's just defined($dispatch{$value}).