Feature Request: Redstone querying

[TheKrumpet]

It'd be nice if we could have a way of tagging and querying redstone sources to allow us to only take actions depending on these signals.

Main use case is for things such as ME level emitters, which would allow us to take action to deal with item overflow or maintaining minimum levels.

I'm thinking something along the lines of

if redstone source ge 2 then
    -- some action
end

I can also envisage use cases where you could turn on and off item transfer with an array of levers on a cable.

[TeamDman]

been thinking a bit about this, might try and make redstone a resource type which would let us reuse existing constructs

proposal:

EVERY 20 TICKS DO
  IF myBlock HAS > 0 redstone:: THEN
  -- idk
 END
END

[target-san]

Maybe consider naming it redstone_signal? It would remove ambiguity with redstone dust and make intention more clear