Elm Puzzler

A framework for creating puzzles & solutions written in Elm, to help newcomers learn the language and then move on to building their own puzzles.

N.B. This is very much a work in progress. Inspired at and by Elm London and intended as an educational tool. Contributions immensely welcome.

A Puzzle

Puzzler exports the Puzzle type, which provides a standardised interface for designing puzzles:

type alias Puzzle state event action =
    { init : state
    , view : state -> Html ()
    , handleTick : state -> Tick -> ( state, Maybe event )
    , handleAction : state -> action -> ( state, Maybe event )
    }

The state defines the internal puzzle state at any given moment

An event is passed from the Puzzle to the Solution, which the Solution may choose to respond to with an

action, which is a Puzzle-defined response to an Event that a Solution may offer

The view function converts the current state into a view for the user. The handleTick function allows the puzzle to update the game state and emit events asynchronously The handleAction function provides a synchronous response to a Solution's Action

A Solution

type alias Solution memory event action =
    { init : memory
    , handleEvent : memory -> event -> ( memory, Maybe action )
    }

A solution has an internal memory that can be used for tracing moves etc. It's initialised with the init function.

The main game logic then is encapsulated in a handleEvent function, which receives the current memory, a new puzzle event, and returns a new memory with an optional action, if required.

Getting Started

Install Elm

git clone https://github.com/jwbrew/elm-puzzler.git

cd elm-puzzler

Running A Puzzle

run :
    Puzzle state event action
    -> Solution memory event action
    -> Program Flags (Model memory state) (Msg action)

Puzzler exports run, which returns a Program. Running the puzzle & solution is as simple as Puzzler.run puzzle solution.

Recommendation: use elm-live with -debug on to enable the time-travelling debugger when developing solutions.

npm i -g elm-live

elm reactor

Puzzles

NoughtsCrosses

Bundled intially there's a naieve implmentation of noughts and crosses. Your opponent is 0, you are X. Your opponent moves first, but has a pretty rubbish strategy.

The demo solution always loses. Try to find a way to make it win.

Writing your own solution

1. Create a file in src/solutions eg src/solutions/MyNoughtsCrossesSolution.elm
2. Import Puzzler.Solution and Action, Event and State from Puzzles.NoughtsCrosses
3. Define a solution : Solution Memory Event Action function, and export.

module Solutions.MyNoughtsCrossesSolution exposing (solution)

import Puzzler exposing (Solution)
import Puzzles.NoughtsCrosses exposing (Action(..), Event(..), State)


type alias Memory =
    ...


takeGo : Memory -> Event -> ( Memory, Maybe Action )
takeGo memory (OpponentMove x y) =
    ...


solution : Solution Memory Event Action
solution =
    { init = []
    , handleEvent = takeGo
    }

4. Modify import Solutions.NoughtsCrosses exposing (solution) in Main.elm to import your solution
5. Run as above!