Updated how the run function handles state.

1. Previously a program's init was just an array assignment. Now its a function that returns a tuple of state and effect: init() { return [state, effect]}
2. Updated README to reflect changes.
3. Updated test for changes.

.eslintrc.json

@@ -29,7 +29,7 @@
     "no-empty": 0,
     "no-ex-assign": 2,
     "no-extra-boolean-cast": 2,
-    "no-extra-semi": 2,
+    "no-extra-semi": 0,
     "no-fallthrough": 2,
     "no-func-assign": 2,
     "no-global-assign": 2,

README.md

@@ -426,13 +426,13 @@ let list = render(<List data={fruits} />, 'section', serverList)
 import { h, render, run } from '@composi/core'
 ```
 
-Run takes one argument, the program to run. This is where it gets interesting. A program has at least three properties:
+Run takes one argument, the program to run. This is where it gets interesting. A program has at least three methods:
 
 1. init
 2. update
 3. view
 
-Init holds the program's state and optionally an effect to run at startup. That's why its called init.
+Init is a function that returns the program's state and optionally an effect to run at startup. That's why its called init.
 
 Update is like a Redux reducer. It executes various actions conditionally. The can modify and return the programs state. When it returns the state, it gets passed to the view.
 
@@ -451,7 +451,7 @@ run(program)
 
 Each property expects certain arguments.
 
-Init must be an array. Its first value is the state for the program. The second, which is optional, is an effect to run at startup. This might be a setInterval timer, or a code to fetch data.
+Init is a function that returns an array. The first entry in that array is the state for the program. The second entry, which is optional, is an effect to run at startup. This might be a setInterval timer, or a code to fetch data.
 
 Update get two arguments: message and state. Message is any message sent to it by the view. Message get sent when events are triggered in the UI, possibly by the user.
 
@@ -474,8 +474,10 @@ function Counter({state, send}) {
 
 // Assemble programe together:
 const program = {
-  // Initial state:
-  init: [0],
+  // Set initial state:
+  init() {
+    return [0]
+  },
   update(msg, state) {
     return [state + 1]
   },
@@ -569,7 +571,9 @@ function List({state, send}) {
 
 // Assemble programe together:
 const program = {
-  init: [state],
+  init() {
+    return [state]
+  },
   update(msg, state) {
     return actions(msg, state)
   },
@@ -691,7 +695,9 @@ function List({state, send}) {
 
 // Assemble program to run:
 const program = {
-  init: [state],
+  init() {
+    return [state]
+  },
   update(msg, state) {
     return actions(msg, state)
   },

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@composi/core",
-  "version": "0.8.6",
+  "version": "0.9.0",
   "description": "A JavaScript library for creating websites, PWAs and hybrid apps.",
   "main": "src/index.js",
   "scripts": {

src/runtime.js

@@ -1,25 +1,25 @@
 /**
  * The @composi/runtime.
- * @typedef {any[]} State
+ * @typedef {any} State
  * @typedef {Function} Effect
  * @typedef {Object<string, any>} Program
- * @prop {Array<State, Effect>} Program.init
- * @prop {function} Program.update
- * @prop {function} Program.view
- * @prop {function} [Program.done]
+ * @prop {Function} Program.init
+ * @prop {Function} Program.update
+ * @prop {Function} Program.view
+ * @prop {Function} [Program.done]
  * @param {Program} program
  * @return {() => void} Function to terminate runtime.
  */
 export function run(program) {
   const update = program.update
   const view = program.view
   const done = program.done
-  let state
+  let state, effect
   let isRunning = true
 
   /**
    * Send a message.
-   * @param {*} message A message of any type.
+   * @param {any} message A message of any type.
    * @return {void} undefined
    */
   function send(message) {
@@ -30,20 +30,22 @@ export function run(program) {
 
   /**
    * Handle changes to state and executing effects.
-   * @param {any[]} change
+   * @param {any[]} update
    * @return {void} undefined
    */
-  function change(change) {
-    state = change[0]
-    let effect = change[1]
+  function change(update) {
+    if (update) {
+      ;[state, effect] = update
+    } else {
+      ;[state, effect] = program.init()
+    }
     if (effect) {
       effect(send)
     }
-    program.init[0] = state
     view(state, send)
   }
 
-  change(program.init)
+  change(state)
 
   /**
    * Function to end runtime.

test/runtime.html

@@ -59,7 +59,9 @@ <h1>Mocha Tests - Composi Runtime &amp; Union</h1>
         return h('h1', { id: 'title' }, `Hello, ${greeting}!`)
       }
       const program = {
-        init: ['World'],
+        init()  {
+          return ['World']
+        },
         update(msg, state) {
 
         },
@@ -96,7 +98,9 @@ <h1>Mocha Tests - Composi Runtime &amp; Union</h1>
       }
 
       const program = {
-        init: ['no message'],
+        init() {
+          return ['no message']
+        },
         update(msg, state) {
           switch (msg.type) {
             case 'click':
@@ -145,7 +149,9 @@ <h1>Mocha Tests - Composi Runtime &amp; Union</h1>
       }
 
       const program = {
-        init: ['no message'],
+        init() {
+          return ['no message']
+        },
         update(msg, state) {
           switch (msg.type) {
             case 'click':
@@ -179,7 +185,9 @@ <h1>Mocha Tests - Composi Runtime &amp; Union</h1>
           effectResult = true
         }
         const program = {
-          init: [0, effect],
+          init() {
+            return[0, effect]
+          },
           update() {
             return [state]
           },
@@ -206,7 +214,9 @@ <h1>Mocha Tests - Composi Runtime &amp; Union</h1>
         }, 100)
       }
       const program = {
-        init: [0, effect],
+        init() {
+          return [0, effect]
+        },
         update() {},
         view() {},
         done() {
@@ -245,7 +255,9 @@ <h1>Mocha Tests - Composi Runtime &amp; Union</h1>
     }
     let taggedEffectFired = false
     const program = {
-      init: ['no message'],
+      init() {
+        return ['no message']
+      },
       update(msg, state) {
         return Msg3.match(msg, {
           'click': () => {
@@ -293,7 +305,9 @@ <h1>Mocha Tests - Composi Runtime &amp; Union</h1>
     }
     let taggedEffectFired = ''
     const program = {
-      init: ['no message'],
+      init() {
+        return ['no message']
+      },
       update(msg, state) {
         return Msg4.match(msg, {
           'click': message => {