stock.yaml

version: 1
name: Stock
description: |
  Learn how to stock inventory when building robots.
objectives:
  - goal:
      - |
        In the previous tutorial challenge, you learned how to use `require`{=snippet}
        to require specific devices to be equipped.
        Sometimes, instead of requiring entities to be equiped as devices, you need them to be stocked in your inventory.
      - |
        In this case, you can write `stock <int> <name>`{=snippet} to ensure that a certain number
        of copies of a certain entity are placed in your inventory. For example:
        ```
        build {stock 2 "flower"; move; place "flower"; move; place "flower"}
        ```
        This would build a robot with two `flower`{=entity}s in its inventory which the robot can then place.
      - Your goal in this challenge is to cover the entire 4x4 gray area with `rock`{=entity}s!
      - |
        **TIP:** You can define commands to simplify your task, for example:
        `def r = move; place "rock"; end`
    condition: |
      def forM = \i.\e. \c. if (i >= e) {} {c i; forM (i+1) e c} end;
      def ifC = \test. \then. \else. b <- test; if b then else end;

      try {
        turn east;
        forM 1 5 (\y.
          forM 1 5 (\x.
            teleport self (x,-y);
            ifC (ishere "rock") {} {grab; noop};
          );
        );
        pure true
      } { pure false }
solution: |
  def x4 = \c. c;c;c;c end;
  def mp = move; place "rock" end;
  def rr = turn right; move; turn right; x4 mp; turn back; x4 move end;
  build {
    stock 16 "rock";
    x4 rr
  };
robots:
  - name: base
    heavy: true
    dir: north
    display:
      char: Ω
      attr: robot
    devices:
      - logger
      - 3D printer
      - dictionary
    inventory:
      - [16, compass]
      - [16, solar panel]
      - [16, logger]
      - [16, treads]
      - [16, grabber]
      - [16, scanner]
      - [16, lambda]
      - [100, rock]
world:
  palette:
    "Ω": [grass, null, base]
    ".": [grass]
    "_": [stone]
    "+": [stone, wall]
  upperleft: [-1, 1]
  map: |
    +++++++
    +Ω....+
    +.____+
    +.____+
    +.____+
    +.____+
    +++++++