lumber

-- http://pastebin.com/4HLi33cn
f,u,d=false,false,false

function look()
  print("look")
  local test,data = turtle.inspect()
  f = test and data or false
  test,data = turtle.inspectUp()
  u = test and data or false
  test,data = turtle.inspectDown()
  d = test and data or false
end

function step()
  print("step")
  look()
  if d and (
    d.name=="minecraft:stone"
    or d.name=="minecraft:dirt"
    or d.name=="minecraft:grass"
  )
  and not f then
    print("plant sapling")
    turtle.select(1)
    turtle.place()
  elseif f and f.name=="minecraft:sapling" then
    print("drop bonemill")
    turtle.select(2)
    turtle.place()
  elseif f and f.name=="minecraft:log" then
    print("Cutting")
    turtle.select(5)
    turtle.dig()
    turtle.digUp()
    turtle.up()
  elseif not f or f.name~="minecraft:log"
  and not d then
    print("landing")
    turtle.down()
  end
end

function main()
  local timer = os.startTimer(.5)
  while true do
    local e,k = os.pullEvent()
    if e=="key" and k==keys.t then
      break
    elseif e=="timer" then
      step()
      timer = os.startTimer(.5)
    end
  end
end


main()