Re: Joe-E

Steven R. Brandt wrote:
> After a little thought, I believe I have an acceptable solution for the 
> problem. In case it is of use, here's what I did to implement a 
> powerless list class:
> 
> public class PowerlessList<T> {

Did you mean to add "implements Powerless"?

Why not use org.joe_e.array.PowerlessArray?  If you want an ordered
sequence of Powerless items, it seems to be exactly what you want:
PowerlessArray is a Powerless, ordered sequence of Powerless items.  As a
bonus, it provides more efficient random access to elements than your
PowerlessList, and the PowerlessArray has a number of utility methods.
And, most importantly, PowerlessArray cleanly handles the issue you
mentioned (it can hold classes explicitly declared Powerless; it can
also handle legacy classes that are honorarily Powerless, like String).

> The key is the holder class. It is able to hold a String, Integer, etc. 
> Essentially, it turns the check from a compile-time to a run-time check, 
> and allows me to use either String or Powerless. Of course, the whole 
> thing might die with a bad type error, so it's a trade-off.

I noticed your implementation hardcodes String, Number, Boolean, and
Character, so it may miss other classes that are honorarily powerless.

Should we add an ImmutableHolder and a PowerlessHolder to the Joe-E
library, written along the lines of the ImmutableArray and PowerlessArray
implementation?  If so, do you want to propose some code?

> The basic problem, I think, is that Powerless is a marker interface. If 
> it were an attribute instead, then I think things would be nicer.

Hmm.  I haven't thought about this, but I'm guessing one challenge
is that this would require re-implementing Java's type checks, so it
might take more work.

> Maybe you could consider this for a future version?

Unfortunately we have no current plans, and no resources, to make major
changes to Joe-E.  We're not actively developing Joe-E at this point;
it's a research project, and we've currently moved on to other projects.