eval(readFile("Worlds_Compiled"))


indent = 0
print = function(x) {
  for (var idx = 0; idx < indent; idx = idx + 1)
    x = '  ' + x
  console.log(x)
}

nothing  = {name: 'nothing'}
outside  = {name: 'outside'}

airlock  = {name: 'airlock',  closed: true}
door     = {name: 'door',     closed: true}
hole     = {name: 'hole'}

rocket   = {name: 'rocket',   entrance: airlock}
building = {name: 'building', entrance: door}
cave     = {name: 'cave',     entrance: hole}

human    = {name: 'human',    loc: rocket}
robot    = {name: 'robot',    loc: rocket,       holding:  nothing}
fuel     = {name: 'fuel',     loc: building,     liftable: true}
key      = {name: 'key',      loc: cave,         liftable: true}
gold     = {name: 'gold',     loc: cave,         liftable: true}

fetch = function(object, place) {
  print("fetching " + object.name + " to " + place.name)
  indent = indent + 1
  if (object.loc !== place) {
    pickup(object)
    moveto(place)
    drop()
  }
  indent = indent - 1
}

pickup = function(object) {
  print("picking up " + object.name)
  indent = indent + 1
  if (!object.liftable)
    abort
  moveto(object.loc)
  if (robot.holding !== nothing)
    drop()
  robot.holding = object
  indent = indent - 1
}

drop = function() {
  if (robot.holding === nothing)
    abort
  print("dropping the " + robot.holding.name + " at " + robot.holding.loc.name)
  robot.holding = nothing
}

moveto = function(place) {
  print("moving to " + place.name)
  indent = indent + 1
  if (robot.loc === place)
    ;
  else {
    if (robot.loc !== outside)
      leave()
    enter(place)
  }
  indent = indent - 1
}

leave = function() {
  print("leaving " + robot.loc.name)
  indent = indent + 1
  if (robot.loc.entrance.closed)
    open(robot.loc.entrance)
  robot.loc = outside
  if (robot.holding !== nothing)
    robot.holding.loc = outside
  indent = indent - 1
}

enter = function(place) {
  print("entering " + place.name)
  indent = indent + 1
  if (place.entrance.closed)
    open(place.entrance)
  robot.loc = place
  if (robot.holding !== nothing)
    robot.holding.loc = place
  indent = indent - 1
}

open = function(x) {
  print("opening " + x.name)
  indent = indent + 1
  if (x === door) {
    if (robot.holding !== key) {
      var oldPlace = robot.loc
      pickup(key)
      moveto(oldPlace)
    }
    door.closed = false
  }
  else if (x === airlock)
    airlock.closed = false
  else
    abort
  indent = indent - 1
}

fetch(gold, rocket)
fetch(fuel, rocket)

fetch(gold, building)

human.loc.name
robot.loc.name
fuel.loc.name
gold.loc.name
key.loc.name
airlock.closed
door.closed