scala.pl

scala.pl

#!/usr/bin/env perl

use strict;
use warnings;

package Seq;

sub apply {
  my ($class, @seq) = @_;
  bless { seq => \@seq }, $class;
}

sub map {
  my $self = shift;
  my $f = shift;
  Seq->apply(map &$f($_), @{$self->{seq}});
}

sub flatten {
  my $self = shift;
  Seq->apply(map ref eq 'ARRAY' ? @$_ : $_, @{$self->{seq}});
}

sub flat_map {
  my $self = shift;
  my $f = shift;
  Seq->apply(map &$f($_), @{$self->{seq}})->flatten();
}

sub foreach {
  my $self = shift;
  my $f = shift;
  &$f($_) foreach @{$self->{seq}};
}

package main;

sub echo {
  my $arg = shift;
  print $arg, $/;
}

sub twice {
  my $arg = shift;
  $arg * 2;
}

my $seq = Seq->apply(1,2,3,4,5);

$seq->foreach(\&echo);
$seq->map(\&twice)->foreach(\&echo);
Seq->apply((1,2),3,(4,5))->flat_map(\&twice)->foreach(\&echo);