Changing the API of mrTriplets?

[rxin]

I've been thinking about this, and I think the mapUDF part of mrTriplets is a little bit confusing because we are asking the user to return an Iterator of (Vid, A).

How about we change mapUDF's signature from EdgeTriplet to (EdgeTriplet, Emitter), and the Emitter has a function sendMessage(targetVid: Vid, message: A)?

This way it should be more efficient, but also more obvious what the mapUDF is doing.

@ankurdave @jegonzal @dcrankshaw

[ankurdave]

That would probably be clearer, though it's a shame to sacrifice immutability/FP principles. If we do this, why not just put sendMessage on EdgeTriplet?

[rxin]

That's a good idea (putting it in EdgeTriplet).

It does make it less "functional". But I don't think it sacrifices immutability though.

[ankurdave]

I worked on this a bit here: https://github.com/ankurdave/graphx/tree/mrTriplets-sendMessage

Compare view: https://github.com/ankurdave/graphx/commit/758e8611d1f8c5ef5debb8034c78053d1e2b9b67