Question

I want to use some function such as “zip”, “fold” and “map” in perl. (Just like in Haskell.) I found map and it works well. Then, is there zip and fold? Thank you very much.

Answer 1

I’ve implemented many of those functions (and even Haskell-like lazy ones) in my module List::Gen

use List::Gen qw(zip reduce);

my @list = zip [1 .. 4], ['a' .. 'd'];

my $str = reduce {$a . $b} @list;

say $str; # 1a2b3c4d

Or using the glob function to build the ranges:

use List::Gen 'glob';

say <1 .. 4>->zip(<a .. d>)->reduce('$a.$b'); # 1a2b3c4d

Using ->reduce('.') or ->reduce(sub {$a . $b}) also works.

Or if you are golfing:

say <[.]>->(<1..4>|<a..d>);

Or for the Haskell versions, see List::Gen::Haskell