#!/usr/bin/env perl
use strict;
use warnings FATAL => 'uninitialized';
use strict;
use warnings;
use warnings FATAL => 'uninitialized';
#use Sub::Call::Tail;
# find modules from functional-perl working directory (not installed)
use Cwd 'abs_path';
our ($mydir, $myname);
BEGIN {
    my $location = (-l $0) ? abs_path($0) : $0;
    $location =~ /(.*?)([^\/]+?)_?\z/s or die "?";
    ($mydir, $myname) = ($1, $2);
}
use lib "$mydir/../lib";
sub sumofsquares {
    my ($from, $to) = @_;
    my $tot = 0;
    for (my $i = $from; $i <= $to; $i++) {
        $tot + = $i * $i;
    }
    $tot
}
sub Gsumofsquares {
    my ($from, $to) = @_;
    my $tot = 0;
    my $i   = $from;
test:
    goto calculate if $i <= $to;
    return $tot;
calculate:
    $tot + = $i * $i;
    $i++;
    goto test;
}
use Chj::TEST ":all";
TEST {
    [map { [sumofsquares(@$_), Gsumofsquares(@$_)] }
            ([0, 4], [1, 5], [3, 7], [-2, 4])]
}
[[30, 30], [55, 55], [135, 135], [35, 35]];
use FP::Repl;
repl;