Yatzy Dice Roller

The game

Yatzy is a dice game where one to any number of players take turn rolling five dices.

After the first roll the player can choose to keep or re-roll dices up to two times in a turn.

A score must be put on the score card when the player has no more re-rolls; if the roll yielded a score of zero points one of the options must me sacrificed. The game ends when there are no more options on the score card.

The player with the highest total score wins the game.

The exercise

Build a dice roller that let's a player roll 5 dices by hitting the Space or Enter key.

Note that this exercise does not involve keeping track of players or their scores.

• Create a simple view function Int -> Element, that returns an image of the appropriate dice side (find images in assets/ folder)

• Use the provided randomSide to exercise your view

• Create a Model that can hold the generated roll value and the new seed

• Write an update function to udpate your Model. Remember to update both roll and seed.

• Wire things up using Signal.map and Signal.foldp and an approprate Signal from Keyboard module

• Extend the view and Model to handle 5 dices

• enable the jsFeed port and load index.html to get a random starting point

Extra tasks

• Let the player use either Return or Space to roll the dices

• Let a user select dices to "hold" during next roll. E.g. selecting a dice could be using the numeric keys (1..5), 0 could clear held dices. For KeyCodes you could look at using the package key-constants

• Integrate the Yatzy Score module from last elmcph evening to show possible scores after a roll

How to get started

Fork this repository to your own GitHub account. This will allow us to compare solutions using the forks view for this project on Github.

Then do the following

git clone [email protected]:<your github account>/yatzy-dice-roller
cd yatzy-dice-roller
elm make --output elm.js Yatzy/Roller.elm
elm reactor

Start by opening the Roller.elm directly in the reactor: http://localhost:8000/Yatzy/Roller.elm

When you enable the jsSeed port, you should switch to http://localhost:8000/index.html to the the port initialized, but then you need to compile your Roller.elm manually (to elm.js - see above)

Note screen will be blank until you start filling doing the exercise

Attribution

The inspiration and assets used in this exercise comes from Joseph Collard's examples of generating random numbers in Elm.