haskell-karel/interface.md

Karel Language Reference

Primitives

• step :: Karel -> Karel
  Moves Karel one intersection forward.
• turnLeft :: Karel -> Karel
  Pivots Karel 90 degrees left.
• pickBeeper :: Karel -> Karel
  Takes a beeper from the current intersection and puts it in the beeper bag.
• putBeeper :: Karel -> Karel
  Takes a beeper from the beeper bag and puts it at the current intersection.

Sensors

• frontIsClear :: Karel -> Bool
  Returns True if there is no wall directly in front of Karel. Returns False if there is a wall.
• beepersPresent :: Karel -> Bool
  Returns True if Karel is standing at an intersection that has a beeper, False otherwise.
• facing :: Direction -> Karel -> Bool
  Returns True if Karel is facing queried direction, False otherwise.
• facingNorth :: Karel -> Bool
  Returns True if Karel is facing north, False otherwise.
• beepersInBag :: Karel -> Bool
  Returns True if there is at least one beeper in Karel's beeper bag, False if the beeper bag is empty.

Creating world

• worldWithDimensions :: Vector -> World
  Takes a pair of integers, specifying dimensions of a world (width, height) and returns new world.
• setBeepersAt :: Vector -> Int -> World -> World
  Sets beepers at specified position, if beepers = 0 => removes them, negative count or position not in the world results in error.
• addWallAt :: Vector -> Direction -> World -> World
  Adds wall at specified position to specified direction, if position is not in the world, results in error.
• removeWallAt :: Vector -> Direction -> World -> World
  Removes wall at specified position to specified direction, if position is not in the world, results in error.

Creating Karel

• defaultKarel :: World -> Karel
  Creates Karel instance with a given world. Karel is defaultly placed at (1, 1), facing East with no beepers in his bag.
• initialPosition :: Vector -> Karel -> Karel
  Sets Karel's initial position, if position is out of the world, results in error.
• initialDirection :: Direction -> Karel -> Karel
  Sets Karel's initial direction.
• initialBeepersInBag :: Int -> Karel -> Karel
  Sets Karel's initial beepers in bag, if negative number is given, results in error.

Super Karel Language Reference

Super Karel is an extension to the basic Karel the Karel library. Super Karel is "equipped" with additional sensors.

Sensors

• frontIsBlocked :: Karel -> Bool
  Returns True if there is a wall directly in front of Karel, False otherwise.
• leftIsClear :: Karel -> Bool
  Returns True if there is no wall immediately to Karel's left, False if there is.
• leftIsBlocked :: Karel -> Bool
  Returns True if there is a wall immediately to Karel's left, False otherwise.
• rightIsClear :: Karel -> Bool
  Returns True if there is no wall immediately to Karel's right, False if there is.
• rightIsBlocked :: Karel -> Bool
  Returns True if there is a wall immediately to Karel's right, False otherwise.
• no_beepers_present :: Karel -> Bool
  Returns True if there is not beeper at the current intersection, False if there is a beeper at the current intersection.
• notFacing :: Direction -> Karel -> Bool
  Returns True if Karel is not facing queried direction, False if he is not.
• notFacingNorth :: Karel -> Bool
  Returns True if Karel is not facing north, False if he is facing north.
• facingSouth :: Karel -> Bool
  Returns True if Karel is facing south, False otherwise.
• notFacingSouth :: Karel -> Bool
  Returns True if Karel is not facing south, False if he is facing south.
• facingEast :: Karel -> Bool
  Returns True if Karel is facing east, False otherwise.
• notFacingEast :: Karel -> Bool
  Returns True if Karel is not facing east, False if he is facing east.
• facingWest :: Karel -> Bool
  Returns True if Karel is facing west, False otherwise.
• notFacingWest :: Karel -> Bool
  Returns True if Karel is not facing west, False if he is facing west.
• noBeepersInBag :: Karel -> Bool
  Returns True if Karel's beeper bag is empty, False if there is at least one beeper in the beeper bag.