bind2.yaml

version: 1
name: Bind notation
creative: false
description: |
  Learn about command return types and how to bind the results.
objectives:
  - id: grab_artifact
    teaser: Retrieve artifact
    goal:
      - |
        A pedestal stands conspicuously empty in the center of the room.
        Perhaps its intended contents lie nearby?
      - |
        Build a robot to retrieve and restore the mystery artifact to its proper place
        in the center of the pedestal!
      - |
        The robot will need to `place "ARTIFACT NAME"`{=snippet}, but you do not know the name yet!
        Fortunatelly, the `grab` command has type `Cmd Text`{=type}, and returns
        the name of the grabbed entity as a text value.
      - |
        To use the result of a command later, you need _bind notation_, which
        consists of a variable name and a leftwards-pointing arrow
        before the command. Like this:
      - |
        `move; art <- grab; place art`
      - |
        **NOTE:** If you find yourself stuck, you can select "Start over" from
        the "Quit" (**Ctrl+Q**) dialog.
    prerequisite:
      not: fail_to_grab
    condition: |
      try {
        teleport self (0,3);
        ishere "Hastur"
      } { pure false }
  - id: fail_to_grab
    teaser: Robot stopped
    hidden: true
    optional: true
    goal:
      - |
        You sent a robot, but it failed to put the artifact in its rightful place.
      - |
        Try again by selecting "Start over" from the "Quit" (**Ctrl+Q**) dialog.
    condition: |
      as base {
        try {
          r <- robotnumbered 1;
          reprogram r {};
          teleport self (0,3);
          h <- ishere "Hastur";
          pure (not h)
        } {
          pure false
        }
      }
solution: |
  build {
    move; move;
    turn right; move; move;
    f <- grab;
    turn back; move; move;
    turn right; move;
    place f
  }
entities:
  - name: Hastur
    display:
      attr: gold
      char: 'H'
    description:
      - The Unspeakable One
    properties: [pickable]
  - name: pedestal
    display:
      attr: gold
      char: '+'
    description:
      - A stone pedestal.
    properties:
      - boundary
robots:
  - name: base
    dir: north
    display:
      char: Ω
      attr: robot
    devices:
      - 3D printer
      - logger
    inventory:
      - [1, solar panel]
      - [1, treads]
      - [1, grabber]
      - [1, compass]
world:
  palette:
    'Ω': [stone, null, base]
    '.': [blank, null]
    'x': [stone, pedestal]
    's': [stone, null]
    'H': [blank, Hastur]
    '+': [stone, wall]
  upperleft: [-5, 6]
  map: |
    +++++++++++
    +.........+
    +...xxx...+
    +...xsx...+
    +...xxxH..+
    +.........+
    +++++Ω+++++
    ....+++....