I know this is of little practical help to you, but I want to point out a really elegant way of how to do this in Perl 6:

my @big = gather {
   walk()
}
for @big -> $b {
    ...
}

sub walk {
   # do stuff here;
   take $result;
   walk(); # recurse into self
}
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The take is dynamically scoped, so you can call it in a different sub, in a recursive sub etc. Additionally it has the benefit of returning a lazy list, which means that the computation is only carried out if the data is really needed.

I imperfectly back-ported that behaviour to perl 5 with the module Perl6::GatherTake.