Refactor boolean cast code, add tests

[navis]

Currently binary operators in math expr returns integer 0 or 1 for long type arguments, making following expressions regard it as a double. I think returning 0L / 1L would make it more consistent.

[nishantmonu51]

travis timed out -
https://travis-ci.org/druid-io/druid/jobs/132758321

[gianm]

👍 LGTM

[gianm]

Seems like a strange definition of asBoolean (I would expect Evals.asBoolean(x) to be equivalent to x != 0). But it looks like the behavior was already like this, so no need to change it here.

[dclim]

👍 LGTM, @navis when you fix the merge conflicts we can pull this in

[navis]

@dclim most of issues described here are fixed in #2836. this can be simple refactoring over it ( or should I merge this into it?)

[dclim]

@navis there's not too many changes here, I'm fine either way

[fjy]

@navis any chance we can finish this up?

[fjy]

@navis ping

[navis]

@fjy rebased on master

[gianm]

It looks like post-rebasing this is no longer fixing anything or changing behavior (the new EvalTest passes even on master) but is instead just refactoring the boolean cast code and adding a new test. Still valuable, but I'm going to change the PR title to reflect that.

[gianm]

LGTM