Pseudo-Ruby code for TOM.

main.rb

# The application for controlling the Blu-tack device.
module BluTacker

  # Function to manage the main function of the device.
  def main

    # A continuous loop which manages the device's operation.
    loop do {

      # Scan the wall for a poster and store the data in the "poster" variable.
      poster = self.scanWall

      # Check if the poster needs new Blu-tack.
      if posterNeedsBlutack?(poster)

        # Find a safe path to the poster.
        navigateToPosterSafely(poster)

        # Stick the poster to the wall.
        stickPoster(poster)
      else

        # If the poster doesn't need new Blu-tack, return to the start.
        next

      end
    }
  end

  # Device function to check if a poster needs blutack.
  def posterNeedsBlutack?(posterLocation)

    # Get the temperature of the poster's blutack and store it in the "blutackTemp" variable.
    blutackTemp = self.getBluTacktemp(posterLocation);

    # If the temperature is less than 20 degrees, the poster DOES need blutack (TRUE).
    if blutackTemp < 20
      needsBlutack? = true

    # Otherwise the poster DOESN'T need blutack (FALSE).
    else
      needsBlutack? = false
    end

    # Inform the main device program if the poster needs Blu-tack.
    return needsBlutack?
  end

  # Main device function to perform a series of movements to stick a poster to the wall.
  def stickPoster(poster)

    # Run in a loop to stick all of the corners.
    loop do {

      # Break the loop when all 4 corners have been stuck (number of completed corners equals 4).
      break if poster.completedCorners == 4

      # Only try to stick a corner if the device doesn't have an obstacle in its way.
      if not self.hasObstacle?

        # Move to the next corner of the poster.
        moveToCorner()

        # Put a piece of blutack in the corner where the device is now located.
        placeBlutack(poster.currentCorner)

        # Update the number of corners completed.
        completedCorners = completedCorners + 1


      # Execute this code if an obstacle is found.
      else
        sleep(1) # Wait for the obstacle to be removed.
        next # Try again.
      end
    }
  end

  # Function to navigate the device along a safe path toward the poster.
  def navigateToPosterSafely(posterLocation)

    # Run in a loop while the device is not located at the poster.
    while (self.location != posterLocation) {

      # Move toward the poster if there is not an obstacle.
      if not self.hasObstacle?
        moveToPoster()

      # Execute this code if an obstacle is found.
      else
        sleep(1) # Wait for the obstacle to be removed.
        next # Try again.
      end
    }

  end
end