Here is a version of
Re (tilly) 1 (perl): What Happened...(perils of porting from c):
#!/usr/bin/perl
use strict;
use warnings;
my @array = ( [1..3],['a'..'b'],['A'..'C'] );
my @prev_value;
nested_for(
sub {
if (@prev_value) {
my $diff;
for (0..$#prev_value) {
if ($prev_value[$_] ne $_[$_]) {
$diff = $_;
last;
}
}
if (defined $diff) {
for (reverse $diff..$#prev_value) {
print " ", @prev_value[0..$_];
}
print "\n";
} else {
print " ";
}
}
print @_;
@prev_value = @_[0..$#_-1];
}, reverse @array);
sub nested_for {
ret_iter(@_)->();
}
sub ret_iter {
my $fn = shift;
my $range = shift;
my $sub = sub { $fn->(@_, $_) for @$range };
return @_ ? ret_iter($sub, @_) : $sub;
}