1575-ensure-single-recognition.yaml

version: 1
name: Structure recognizer - single recognition
description: |
  Ensure that only a single structure is recognized
  when placing an entity would complete more than one
  structure template.
creative: false
objectives:
  - teaser: Build 2 `chessboard`{=structure}s
    prerequisite:
      not: premature_win
    goal:
      - |
        Build 2 of the same structure
    condition: |
      def length : (rec l. Unit + a * l) -> Int = \l.
        case l (\_. 0) (\cons. match cons \_. \rest. 1 + length rest)
      end;
      foundStructures <- structures "chessboard";
      pure $ length foundStructures >= 2;
  - id: premature_win
    teaser: Don't count win early
    optional: true
    goal:
      - |
        Two structures shouldn't be recognized
        while the bases still possesses `gold`{=entity}
    condition: |
      def length : (rec l. Unit + a * l) -> Int = \l.
        case l (\_. 0) (\cons. match cons \_. \rest. 1 + length rest)
      end;
      robotHasGold <- as base {has "gold"};

      foundStructures <- structures "chessboard";
      pure $ length foundStructures >= 2 && robotHasGold;
robots:
  - name: base
    dir: south
    devices:
      - grabber
      - treads
    inventory:
      - [1, gold]
      - [1, silver]
solution: |
  move;
  place "silver";
  move; move; move;
  turn left;
  move; move; move; move;
  place "gold";
structures:
  - name: chessboard
    recognize: [north]
    structure:
      mask: '.'
      palette:
        'g': [stone, gold]
        's': [stone, silver]
      map: |
        gsgs
        sgsg
        gsgs
        sgsg
world:
  name: root
  dsl: |
    {blank}
  palette:
    '.': [grass]
    'g': [grass, gold]
    's': [grass, silver]
    'B': [grass, null, base]
  upperleft: [0, 0]
  map: |
    ...B....
    gsg.gsgs
    sgsgsgsg
    gsgsgsgs
    sgsgsgs.