That's the same thing as:

$iter_prod = NestedLoops([
   sub { iter(qw(a b c) },
   sub { iter(qw(x y z) },
]);

[download]

Wasn't the whole point to avoid flattening the iterator and to provide arbitrary nesting? Your solution flattens, and the depth is hardcoded as a sequence of calls to iter_prod.

Note: NestedLoops's iterator returns an array rather than an array ref.

Update: Your solution does support arbitrary depth:

my $iter = do { my $done = 0;  sub { $done++ ? undef : 1 } };
iter_prod($iter, ...) if ...;
iter_prod($iter, ...) if ...;

[download]

With NestedLoops, you'd do:

my @iters;
push(@iters, ...) if ...;
push(@iters, ...) if ...;

[download]

In reply to Re^2: NestedLoops (Algorithm::Loops) and Iterators by ikegami
in thread NestedLoops (Algorithm::Loops) and Iterators by mrborisguy

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