Day 95: Make Mine Mini

Today I made the first addition to the engine.rb file in a very long time; I moved the Waker module over to it. The Waker module is what implements continuations, which if I'd known about them when I originally started this project, would have been even more integrated into the engine.

Basically, here's what TraderMissions code for handling a dialog would look like, if TM was in Ruby:

# Called every time this state becomes
# the active one.
def activate
  if @dialog.yes?
    do_things
  end
  if @other_dialog.stuff?
    do_other_things
  end
end

The activate function has to check every possible state that it might transition into, see if it was called and if so what its result was, and deal with that. This rapidly becomes horrible. Whereas with continuations:

def activate
  @continue.call if @continue
end

And that's set up when I originally transition to the other state:

def verify_cheese
  cv = CheeseVerifier.new
  callcc do | cont |
    @continue = cont
    @driver << cv
  end

  enable_cheese if cv.yes?
end

@continue.call moves execution back to after the block where I originally set @continue, thus letting me pick up where I had transitioned away from the current state. Hooray for continuations!

Oh, right, the subject. I'd actually done that continuation stuff months ago, the Waker thing was me moving it. Most of the day was me creating a simple object selector. I thought to myself "I need a MiniBuilder equivalent for those children which only have one object. Thus:

THE MINICHOOSER!