super return

Alexander Jones alex at
Wed Aug 30 16:08:05 UTC 2017

Perhaps if the nested function is lexically inside such super function it
can be fair game and actually quite powerful and liberating.

Unconstrained 'upleveling' is IIRC valid in such wonderful languages as
Tcl. This unverified fact is presented without opinion :D

On Tue, 29 Aug 2017 at 16:57, Allen Wirfs-Brock <allen at>

> On Aug 28, 2017, at 12:29 PM, Sebastian Malton <sebastian at>
> wrote:
> The outcome of this basically means "return from current context up one
> level and then return from there”.
> This would be a terrible violation of functional encapsulation.  How do
> you know that the (e.g.) forOf function isn’t internally using a
> encapsulated helper function that is making the actual call to the call
> back.  You simply have no way to predict where returning from the current
> context “up one” means.
> A current method of doing this is by using try / catch but it is not
> ideal. Using the above method I believe that it would be able to be better
> optimized.
> This technique provides a meaningful semantics because it allows the
> controlling outer function to define what early return means.
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