The missing game loop for your Pure function.

You just have to define your initial state and an update function, then the loop takes care of the rest, it will call update in each iteration with the currentState and input, or it will terminate if the isGameOver property in your state is true or the user presses q.

Example usage

Install:

npm install adamgonda/loop

// in your index.js
const { run } = require('loop')

run({
  initialState: {
    player: { x: 10, y: 5, isHappy: true },
    view: { width: 20, height: 10 },
    isGameOver: false,
  },
  update: (state, input) => state,
  toCommon: (state) => [{ ...state.player, tag: 'player' }],
  renderMap: { player: 'X' },
  dimensions: { width: 20, height: 10 }
})

when you run node ./index.js it will produce a running game that looks like this 👇

{ player: { x: 10, y: 5 } }
input null
-----------------------
|                     |
|                     |
|                     |
|                     |
|                     |
|          X          |
|                     |
|                     |
|                     |
|                     |
|                     |
-----------------------

API

Loop exports one function run.

run({
  // required: starting point for a game
  // it has to contain properties:
  //   loop uses this to know when to terminate the game
  //   isGameOver: boolean
  //   
  //   loop uses this to know how big the view has to be
  //   view: { width: number, height: number }
  // example 👇
  initialState: {
    player: { x: 10, y: 5, isHappy: true },
    view: { width: 20, height: 10 },
    isGameOver: false,
  },

  // required: implements the main game logic
  // example 👇
  update: (state, input) => state,

  // required: transforms every unique game state to a common form
  // which is a list of objects with x, y and a tag property
  // example 👇
  toCommon: (state) => [{ ...state.player, tag: 'player' }],

  // required: maps tags to characters
  // example 👇
  renderMap: { player: 'X' },

  // optional, maps a numeric character from the console to a value relevant to you
  // example 👇
  // inputMap: { '119': 'UP', '115': 'DOWN' }

  // optional, function (state) => void, called before and after render
  // example 👇
  // header: (state) => console.log('This is the header'),
  // footer: (state) => console.log('This is the footer'),

  // optional, default is 100, determines time between renders
  // example 👇
  // timeBetweenRender: 50,

  // optional, default true, logs state and input
  // example 👇
  // isDebug: false
})