Flow code

.flowconfig

@@ -0,0 +1,9 @@
+[ignore]
+.*/test/.*
+.*/scripts/.*
+
+[include]
+
+[libs]
+
+[options]

README.md

@@ -1,74 +1,62 @@
-## A step by step solver for math
+# Mathsteps
+[![Join the chat at https://gitter.im/mathsteps-chat/Lobby](https://badges.gitter.im/mathsteps-chat/Lobby.svg)](https://gitter.im/mathsteps-chat/Lobby?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge) [![Build Status](https://travis-ci.org/socraticorg/mathsteps.svg?branch=master)](https://travis-ci.org/socraticorg/mathsteps)
 
-[![Join the chat at https://gitter.im/mathsteps-chat/Lobby](https://badges.gitter.im/mathsteps-chat/Lobby.svg)](https://gitter.im/mathsteps-chat/Lobby?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
-[![Build Status](https://travis-ci.org/socraticorg/mathsteps.svg?branch=master)](https://travis-ci.org/socraticorg/mathsteps)
+Mathsteps is a step-by-step math solver. It helps in solving equations, simplifying an expression and factoring a polynomial. (more to come 😄)
 
-https://www.youtube.com/watch?v=iCrargw1rrM
+**Solve an equation**
 
-## Requirements
-
-Mathsteps requires Node version > 6.0.0
-
-## Usage
+```javascript
+const steps = mathsteps.solveEquation('2x + 3x = 35');
+```
 
-To install mathsteps using npm:
+**See all the change types**
+```javascript
+const changes = mathsteps.ChangeTypes;
+```
+Learn [how to use mathsteps](https://github.com/socraticorg/mathsteps/wiki/How-to-use-mathsteps) and [how the codebase works](https://github.com/socraticorg/mathsteps/wiki/Mathsteps-organization).
 
-    npm install mathsteps
+## Examples
+Here is an example to get you started.
 
-```js
+```javascript
 const mathsteps = require('mathsteps');
 
 const steps = mathsteps.simplifyExpression('2x + 2x + x + x');
 
 steps.forEach(step => {
-	console.log("before change: " + step.oldNode);         // before change: 2 x + 2 x + x + x
-	console.log("change: " + step.changeType);             // change: ADD_POLYNOMIAL_TERMS
-	console.log("after change: " + step.newNode);          // after change: 6 x
-	console.log("# of substeps: " + step.substeps.length); // # of substeps: 3
+    console.log("before change: " + step.oldNode);        
+    console.log("change: " + step.changeType);             
+    console.log("after change: " + step.newNode);          
+    console.log("no of substeps: " + step.substeps.length); 
 });
-```
-
-To solve an equation:
-```js
-const steps = mathsteps.solveEquation('2x + 3x = 35');
 
-steps.forEach(step => {
-    console.log("before change: " + step.oldEquation.print());  // e.g. before change: 2x + 3x = 35
-    console.log("change: " + step.changeType);                  // e.g. change: SIMPLIFY_LEFT_SIDE
-    console.log("after change: " + step.newEquation.print());   // e.g. after change: 5x = 35
-    console.log("# of substeps: " + step.substeps.length);      // e.g. # of substeps: 2
-});
+/* 
+before change: 2 x + 2 x + x + x
+change: ADD_POLYNOMIAL_TERMS
+after change: 6 x
+no of substeps: 3
+*/
 ```
+In this example we have an equation `2x + 2x + x + x` that is being simplified by the method `simplifyExpression`. It returns the output which tells about the equation before and after applying the change, what change was applied and the no of substeps.
 
-To see all the change types:
-```js
-const changes = mathsteps.ChangeTypes;
+## Installation
+Mathsteps is available as the `mathsteps` package on [npm](https://www.npmjs.com/package/mathsteps). 
+```
+npm install mathsteps --save
 ```
-
-
 
 ## Contributing
+The main objective of the mathsteps is to continue to evolve and provide more operations and features. Read below to learn how can you contribute to the project.
 
-Hi! If you're interested in working on this, that would be super awesome!
-Learn more here: [CONTRIBUTING.md](CONTRIBUTING.md).
-
-## Build
-
-First clone the project from github:
-
-    git clone https://github.com/socraticorg/mathsteps.git
-    cd mathsteps
+**Contributing guide**
 
-Install the project dependencies:
-
-    npm install
+Read our [contributing guide](CONTRIBUTING.md) to suggest more features, report bugs or contribute code.
 
 ## Test
+```
+npm test
+```
 
-To execute tests for the library, install the project dependencies once:
-
-    npm install
-
-Then, the tests can be executed:
+## License 
+Apache-2.0
 
-    npm test

lib/node/Creator.js

@@ -1,14 +1,22 @@
+// @flow
+
 /*
   Functions to generate any mathJS node supported by the stepper
   see http://mathjs.org/docs/expressions/expression_trees.html#nodes for more
   information on nodes in mathJS
 */
 
+type value = string | number;
+
+type baseNode = {
+  [property: string]: value
+}
+
 const math = require('mathjs');
 const NodeType = require('./Type');
 
 const NodeCreator = {
-  operator (op, args, implicit=false) {
+  operator (op: string, args: Array<baseNode>, implicit: boolean=false) {
     switch (op) {
     case '+':
       return new math.expression.node.OperatorNode('+', 'add', args);
@@ -28,27 +36,27 @@ const NodeCreator = {
 
   // In almost all cases, use Negative.negate (with naive = true) to add a
   // unary minus to your node, rather than calling this constructor directly
-  unaryMinus (content) {
+  unaryMinus (content: Array<baseNode>) {
     return new math.expression.node.OperatorNode(
       '-', 'unaryMinus', [content]);
   },
 
-  constant (val) {
+  constant (val: number) {
     return new math.expression.node.ConstantNode(val);
   },
 
-  symbol (name) {
+  symbol (name: string) {
     return new math.expression.node.SymbolNode(name);
   },
 
-  parenthesis (content) {
+  parenthesis (content: baseNode) {
     return new math.expression.node.ParenthesisNode(content);
   },
 
   // exponent might be null, which means there's no exponent node.
   // similarly, coefficient might be null, which means there's no coefficient
   // the symbol node can never be null.
-  polynomialTerm (symbol, exponent, coeff, explicitCoeff=false) {
+  polynomialTerm (symbol: baseNode, exponent: baseNode, coeff: Object, explicitCoeff: boolean=false) {
     let polyTerm = symbol;
     if (exponent) {
       polyTerm = this.operator('^', [polyTerm, exponent]);
@@ -68,7 +76,7 @@ const NodeCreator = {
   },
 
   // Given a root value and a radicand (what is under the radical)
-  nthRoot (radicandNode, rootNode) {
+  nthRoot (radicandNode: baseNode, rootNode: baseNode) {
     const symbol = NodeCreator.symbol('nthRoot');
     return new math.expression.node.FunctionNode(symbol, [radicandNode, rootNode]);
   }

package.json

@@ -13,10 +13,12 @@
     "eslint": "^3.10.2",
     "eslint-config-google": "^0.7.0",
     "eslint-plugin-sort-requires": "^2.1.0",
+    "flow-bin": "^0.43.1",
     "mocha": "2.4.5"
   },
   "scripts": {
     "lint": "node_modules/.bin/eslint .",
+    "flow": "flow",
     "test": "node_modules/.bin/mocha --recursive",
     "setup-hooks": "ln -s ../../scripts/git-hooks/pre-commit.sh .git/hooks/pre-commit"
   },