The recent discussion about if/then/else idioms in ZK has raised the
thought that it might be nice to have some extended semantics.
One version that I could see would be to to extend the current multi-op to
allow multiple alternatives. The idea would be that there would effectively
be multiple branches to be tried. The first one that succeeds atomically
(all or nothing) would be used. The returned value would need to somehow
indicate which alternative succeeded and would need to return any data
accessed. The testing of alternatives would also be atomic so it wouldn't
be possible for things to change within a single operation.
This extension would allow the previous question to be answered like this:
pick_first {
create(...)
} {
set(...)
}
(the syntax here is just made up and wouldn't actually be supported ... it
is just for pseudo code purposes).
My theory is that this would be relatively easy to implement based on the
current multi operation. Risk due to the change is pretty low given that
there is code to copy.
My question is whether this would actually have all that much benefit.
Does anybody have an opinion on that?
