version: 1
name: Cave shaped maze
author: Ondřej Šebek
description: A maze shaped like a cave. It only goes down or forward.
objectives:
- goal:
  - You are at the top of a cave that gradually descends until reaching a dead end.
  - At its bottom is a great treasure.
  - Luckily, the cave does not branch out, so it is easy to find the path to the treasure.
  - Send a robot to the the item marked as '!'. You win once the robot grabs it.
  condition: |
    j <- robotNamed "judge";
    as j {has "goal"}
solution: |
  def until = \p. \c. b <- p; if b {} {c; until p c} end;
  def fwd = until blocked move end;
  build {
    require "branch predictor"; // #540
    turn east;
    until (ishere "goal") (fwd; turn right; fwd; turn left);
    grab
  }
robots:
  - name: base
    dir: [0,1]
    display:
      char: 'Ω'
      attr: robot
    devices:
      - dictionary
      - 3D printer
      - logger
      - grabber
    inventory:
      - [50, solar panel]
      - [50, treads]
      - [50, compass]
      - [50, scanner]
      - [50, lambda]
      - [50, branch predictor]
      - [50, strange loop]
      - [50, logger]
      - [50, grabber]
      - [0, goal]
  - name: judge
    dir: [0,0]
    system: true
    program: |
      def until = \c. b <- c; if b {} {until c} end;
      until (d <- scan down; return (d == inl ()));
      create "goal"
known: [water]
entities:
  - name: wall
    display:
      char: █
      attr: rock
    description:
    - An impassable stone wall.
    properties: [unwalkable, known]
  - name: goal
    display:
      char: '!'
      attr: device
    description:
    - The place you're trying to reach!  You win by executing `grab` on this item.
    properties: [known, portable]
world:
  default: [ice]
  palette:
    'Ω': [stone, null, base]
    ' ': [stone, null]
    '~': [stone, water]
    '█': [stone, wall]
    '!': [stone, goal, judge]
  upperleft: [0,0]
  map: |
    ██████████████████████████████
    █Ω  ████████ █████████████████
    ███   ██████████████████████ █
    █████ ███████████ ██████████ █
    █████    ███████~███ ███ █████
    ████████ ███████████ ██ ██████
    ███ ████      ██████~█~█ █████
    ██~██████████  █████~~███ █ ██
    ████████ █████  █████████~████
    ███ ███████████   ███████~~███
    ███  █ ███ ██████ ██████~~████
    █ ██ ███   ██████ ████████████
    ██ █   █ ██ █████    █████████
    ██~~~~~~~██~~~██████        !█
    ██████████████████████████████