sub w(&$){&{$_[1]}while&{$_[0]}}sub d(&){$_[0]}
# then, instead of while (foo) { bar },
w{foo}d{bar};

##</code><code>##

sub l(&){{&{$_[0]};redo}}sub w{$_[0]||last}
# then, instead of while (foo) { bar },
l{w foo;bar};