Ruby constructors required to initialize lattices

[jhellerstein]

In order, for example, to initialize an lmax, we have to write code like this:

bootstrap do
    # initialize clock to 0.
    cloq <+ Bud::MaxLattice.new(0)
end

At minimum, this needs to be well documented, but it'd better if we had sugar for it.

[neilconway]

Makes sense. I had thought along the same lines, but I wasn't sure of the right syntax sugar to use. One idea would be to use the wrapper_name as a kind of constructor:

cloq <+ lmax(0)

What do you think? It will require some ugly runtime dispatch to distinguish between the use of the wrapper_name here, vs. the usage in state blocks.

[jhellerstein]

If we want to remain consistent with our initialization of tables, we'd promote Ruby types automatically:

events <+ [['event1'], ['event2']]
cloq <+ 0

Alternatively we could do something OO like:

events <+ table.new(['event1'], ['event2'])
cloq <+ cloq.new(0)

[neilconway]

We already did implicit promotion for array literals (into set lattices) and hash literals (into map lattices), so I think it should be pretty easy to arrange for implicit promotion of other laterals as well.

[neilconway]

Although one annoying property is that you can't pass Fixnum literals to a superator (e.g., <+), because of a superator limitation.

[jhellerstein]

Great. But let's leave the issue open until we get a workaround for <+.

[neilconway]

Another case where the current syntax is kind of annoying is when embedding lattice values inside another lattice -- e.g., as a value in an lmap lattice. Because we don't have parametric types, we can't infer the expected class of the map's values.