initial commit

This commit is contained in:
Mahdi Dibaiee 2015-04-20 13:58:11 +04:30
commit 195777b1af
21 changed files with 1699 additions and 0 deletions

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{
"env": {
"es6": true,
"browser": true
},
"ecmaFeatures": {
"modules": true
},
"globals": {
"exports": true,
"require": true,
"ViewHelpers": true,
"is": true,
"Components": true,
"XPCOMUtils": true,
"EventEmitter": true,
"add_task": true,
"info": true,
"createHost": true,
"promiseTab": true,
"ok": true,
"TEST_URI_ROOT": true,
"TargetFactory": true,
"gBrowser": true,
"gDevTools": true
},
"rules": {
"comma-dangle": [2, "never"],
"no-underscore-dangle": 0,
"no-cond-assign": 0,
"no-undef": 0,
"no-console": 0,
"no-reserved-keys": 2,
"valid-jsdoc": [2, {
"requireReturn": false,
"requireParamDescription": false,
"requireReturnDescription": false
}],
"max-len": [1, 80],
"no-use-before-define": 0,
"no-self-compare": 1,
"no-sequences": 0,
"radix": 2,
"wrap-iife": 2,
"indent": [2, 2],
"brace-style": [2, "1tbs"],
"comma-style": [2, "last"],
"no-lonely-if": 2,
"no-multiple-empty-lines": [2, {"max": 2}],
"quotes": 0,
"space-after-keywords": [2, "always"],
"space-before-blocks": [2, "always"],
"space-infix-ops": [2, { "int32Hint": false }],
"strict": 0,
"global-strict": 0
}
}

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node_modules
.DS_Store
dist

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module.exports = function(grunt) {
grunt.initConfig({
eslint: {
target: ['*.js', 'tests/*.js']
},
babel: {
dist: {
files: [{
expand: true,
src: ['*.js', 'tests/*.js'],
dest: 'dist/'
}]
}
},
mochaTest: {
files: ['dist/tests/*.js']
},
watch: {
scripts: {
files: '**/*.js',
tasks: ['eslint', 'babel']
}
}
});
grunt.loadNpmTasks('grunt-eslint');
grunt.loadNpmTasks('grunt-contrib-watch');
grunt.loadNpmTasks('grunt-babel');
grunt.loadNpmTasks('grunt-mocha-test');
grunt.registerTask('default', [ 'babel']);
grunt.registerTask('test', ['babel', 'mochaTest']);
};

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/*
* Constats
* Keys must be UPPERCASE
* Values Can be a constant value or a function returning a value
* this function doesn't take any arguments (use case: random constats)
*/
export default {
'PI': Math.PI,
'E': Math.E,
'RAND': Math.random
};

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node_modules
.DS_Store
dist

35
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'use strict';
module.exports = function (grunt) {
grunt.initConfig({
eslint: {
target: ['*.js', 'tests/*.js']
},
babel: {
dist: {
files: [{
expand: true,
src: ['*.js', 'tests/*.js'],
dest: 'dist/'
}]
}
},
mochaTest: {
files: ['dist/tests/*.js']
},
watch: {
scripts: {
files: '**/*.js',
tasks: ['eslint', 'babel']
}
}
});
grunt.loadNpmTasks('grunt-eslint');
grunt.loadNpmTasks('grunt-contrib-watch');
grunt.loadNpmTasks('grunt-babel');
grunt.loadNpmTasks('grunt-mocha-test');
grunt.registerTask('default', ['babel']);
grunt.registerTask('test', ['babel', 'mochaTest']);
};

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'use strict';
Object.defineProperty(exports, '__esModule', {
value: true
});
/*
* Constats
* Keys must be UPPERCASE
* Values Can be a constant value or a function returning a value
* this function doesn't take any arguments (use case: random constats)
*/
exports['default'] = {
PI: Math.PI,
E: Math.E,
RAND: Math.random
};
module.exports = exports['default'];

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'use strict';
Object.defineProperty(exports, '__esModule', {
value: true
});
var parseFormat = function parseFormat(a) {
var split = a.split('1');
return {
left: split[0].length,
right: split[1].length
};
};
exports.parseFormat = parseFormat;
var isNumber = function isNumber(a) {
return !isNaN(+a);
};
exports.isNumber = isNumber;
var parseNumbers = (function (_parseNumbers) {
function parseNumbers(_x) {
return _parseNumbers.apply(this, arguments);
}
parseNumbers.toString = function () {
return _parseNumbers.toString();
};
return parseNumbers;
})(function (a) {
return a.map(function (b) {
if (isNumber(b)) {
return parseFloat(b);
}
if (Array.isArray(b)) {
return parseNumbers(b);
}
return b;
});
});
exports.parseNumbers = parseNumbers;
var dive = function dive(arr, n) {
var result = arr;
for (var i = 0; i < n; ++i) {
result = result[result.length - 1];
}
return result;
};
exports.dive = dive;
var deep = (function (_deep) {
function deep(_x2, _x3) {
return _deep.apply(this, arguments);
}
deep.toString = function () {
return _deep.toString();
};
return deep;
})(function (arr, n) {
var index = arguments[2] === undefined ? 0 : arguments[2];
if (n < 2) {
return { arr: arr, index: index };
}
var d = arr.reduce(function (a, b, i) {
if (Array.isArray(b)) {
var _deep2 = deep(b, n - 1, i);
var _arr = _deep2.arr;
var x = _deep2.index;
var merged = a.concat(_arr);
index = x;
return merged;
}
return a;
}, []);
return { arr: d, index: index };
});
exports.deep = deep;
var diveTo = (function (_diveTo) {
function diveTo(_x4, _x5, _x6) {
return _diveTo.apply(this, arguments);
}
diveTo.toString = function () {
return _diveTo.toString();
};
return diveTo;
})(function (arr, indexes, replace) {
var answer = [];
if (indexes.some(Array.isArray)) {
var _iteratorNormalCompletion = true;
var _didIteratorError = false;
var _iteratorError = undefined;
try {
for (var _iterator = indexes[Symbol.iterator](), _step; !(_iteratorNormalCompletion = (_step = _iterator.next()).done); _iteratorNormalCompletion = true) {
var index = _step.value;
answer.push(diveTo(arr, index, replace));
}
} catch (err) {
_didIteratorError = true;
_iteratorError = err;
} finally {
try {
if (!_iteratorNormalCompletion && _iterator['return']) {
_iterator['return']();
}
} finally {
if (_didIteratorError) {
throw _iteratorError;
}
}
}
} else {
arr[indexes[0]] = replace;
return replace;
}
return answer;
});
exports.diveTo = diveTo;
var flatten = (function (_flatten) {
function flatten(_x7) {
return _flatten.apply(this, arguments);
}
flatten.toString = function () {
return _flatten.toString();
};
return flatten;
})(function (arr) {
if (!Array.isArray(arr) || !arr.some(Array.isArray)) {
return arr;
}
return arr.reduce(function (a, b) {
return a.concat(flatten(b));
}, []);
});
exports.flatten = flatten;
var removeSymbols = function removeSymbols(string) {
return string.replace(/\W/g, '');
};
exports.removeSymbols = removeSymbols;

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'use strict';
var _interopRequireWildcard = function (obj) { return obj && obj.__esModule ? obj : { 'default': obj }; };
var _slicedToArray = function (arr, i) { if (Array.isArray(arr)) { return arr; } else if (Symbol.iterator in Object(arr)) { var _arr = []; var _n = true; var _d = false; var _e = undefined; try { for (var _i = arr[Symbol.iterator](), _s; !(_n = (_s = _i.next()).done); _n = true) { _arr.push(_s.value); if (i && _arr.length === i) break; } } catch (err) { _d = true; _e = err; } finally { try { if (!_n && _i['return']) _i['return'](); } finally { if (_d) throw _e; } } return _arr; } else { throw new TypeError('Invalid attempt to destructure non-iterable instance'); } };
var _toConsumableArray = function (arr) { if (Array.isArray(arr)) { for (var i = 0, arr2 = Array(arr.length); i < arr.length; i++) arr2[i] = arr[i]; return arr2; } else { return Array.from(arr); } };
Object.defineProperty(exports, '__esModule', {
value: true
});
var _ReadStream = require('./readstream');
var _ReadStream2 = _interopRequireWildcard(_ReadStream);
var _operators = require('./operators');
var _operators2 = _interopRequireWildcard(_operators);
var _constants = require('./constats');
var _constants2 = _interopRequireWildcard(_constants);
var _import = require('./helpers');
var _ = _interopRequireWildcard(_import);
var Mathstring = {
/**
* Solves the given math expression, following these steps:
* 1. Replace constants in the expression
* 2. parse the expression, separating numbers and operators into
* an array
* 3. Sort the stack by operators' precedence, it actually groups the
* operator with it's arguments n-level deep
* 4. Apply parseFloat to numbers of the array
* 5. Solve groups recursively
*
* @param {String} expression
* The math expression to solve
* @return {Number}
* Result of the expression
*/
solve: function solve(expression) {
// replace constants with their values
expression = replaceConstants(expression);
var stack = parseExpression(expression);
stack = sortStack(stack);
stack = _.parseNumbers(stack);
stack = solveStack(stack);
return stack;
},
/**
* Creates an equation function which replaces variables
* in the given expression with the values specified in order,
* and solves the new expression
*
* Example:
* equation('x+y+z')(2, 5, 6) => solve('2+5+6')
*
* @param {String} expression
* The expression to create an equation for (containing variables)
* @return {Function}
* The function which replaces variables with values in order
* and solves the expression
*/
equation: function equation(expression) {
var stack = parseExpression(expression);
var variables = [];
stack.forEach(function (a) {
if (!_.isNumber(a) && !_operators2['default'][a] && a === a.toLowerCase()) {
// grouped variables like (y) need to have their parantheses removed
variables.push(_.removeSymbols(a));
}
});
return function () {
for (var _len = arguments.length, args = Array(_len), _key = 0; _key < _len; _key++) {
args[_key] = arguments[_key];
}
expression = expression.replace(/[a-z]*/g, function (a) {
var index = variables.indexOf(a);
if (index > -1) {
return args[index] || 0;
}
return a;
});
console.log(variables, expression);
return Mathstring.solve(expression);
};
}
};
var solveStack = (function (_solveStack) {
function solveStack(_x) {
return _solveStack.apply(this, arguments);
}
solveStack.toString = function () {
return _solveStack.toString();
};
return solveStack;
})(function (stack) {
// $0(stack);
if (stack.some(Array.isArray)) {
stack = stack.map(function (group) {
if (!Array.isArray(group)) {
return group;
}
return solveStack(group);
});
return solveStack(stack);
} else {
return evaluate(stack);
}
});
var PRECEDENCES = Object.keys(_operators2['default']).map(function (key) {
return _operators2['default'][key].precedence;
});
var MAX_PRECEDENCE = Math.max.apply(Math, _toConsumableArray(PRECEDENCES));
var MIN_PRECEDENCE = Math.min.apply(Math, _toConsumableArray(PRECEDENCES));
/**
* Parses the given expression into an array of separated
* numbers and operators/functions.
* The result is passed to parseGroups
*
* @param {String} expression
* The expression to parse
* @return {Array}
* The parsed array
*/
var parseExpression = function parseExpression(expression) {
var stream = new _ReadStream2['default'](expression),
stack = [],
record = '';
// Create an array of separated numbers & operators
while (stream.next()) {
var cur = stream.current();
if (cur === ' ') {
continue;
}
// it's probably a function with a length more than one
if (!_.isNumber(cur) && !_operators2['default'][cur] && cur !== '.') {
record += cur;
} else if (record.length) {
stack.push(record, cur);
record = '';
} else if (_.isNumber(stack[stack.length - 1]) && (_.isNumber(cur) || cur === '.')) {
stack[stack.length - 1] += cur;
} else {
stack.push(cur);
}
}
if (record.length) {
stack.push(record);
}
// $0(stack);
return parseGroups(stack);
};
/**
* Takes the parsed array from parseExpression and
* groups up expressions in parantheses in deep arrays
*
* Example: 2+(5+4) becomes [2, [5, '+', 4]]
*
* @param {Array} stack
* The parsed expression
* @return {Array}
* Grouped up expression
*/
var parseGroups = function parseGroups(stack) {
// Parantheses become inner arrays which will then be processed first
var sub = 0;
return stack.reduce(function (a, b) {
if (b[b.length - 1] === '(') {
if (b.length > 1) {
_.dive(a, sub).push(b.slice(0, -1), []);
} else {
_.dive(a, sub).push([]);
}
sub++;
} else if (b === ')') {
sub--;
} else {
_.dive(a, sub).push(b);
}
return a;
}, []);
};
/**
* Gives information about an operator's format
* including number of left and right arguments
*
* @param {String/Object} operator
* The operator object or operator name (e.g. +, -)
* @return {Object}
* An object including the count of left and right arguments
*/
var formatInfo = function formatInfo(operator) {
var op = typeof operator === 'string' ? _operators2['default'][operator] : operator;
if (!op) {
return null;
}
var format = op.format.split('1'),
left = format[0].length,
right = format[1].length;
return { left: left, right: right };
};
/**
* Groups up operators and their arguments based on their precedence
* in deep arrays, the higher the priority, the deeper the group.
* This simplifies the evaluating process, the only thing to do is to
* evaluate from bottom up, evaluating deep groups first
*
* @param {Array} stack
* The parsed and grouped expression
* @return {Array}
* Grouped expression based on precedences
*/
var sortStack = (function (_sortStack) {
function sortStack(_x2) {
return _sortStack.apply(this, arguments);
}
sortStack.toString = function () {
return _sortStack.toString();
};
return sortStack;
})(function (stack) {
var _iteratorNormalCompletion = true;
var _didIteratorError = false;
var _iteratorError = undefined;
try {
for (var _iterator = stack.entries()[Symbol.iterator](), _step; !(_iteratorNormalCompletion = (_step = _iterator.next()).done); _iteratorNormalCompletion = true) {
var _step$value = _slicedToArray(_step.value, 2);
var index = _step$value[0];
var item = _step$value[1];
if (Array.isArray(item)) {
stack.splice(index, 1, sortStack(item));
}
}
} catch (err) {
_didIteratorError = true;
_iteratorError = err;
} finally {
try {
if (!_iteratorNormalCompletion && _iterator['return']) {
_iterator['return']();
}
} finally {
if (_didIteratorError) {
throw _iteratorError;
}
}
}
for (var i = MIN_PRECEDENCE; i <= MAX_PRECEDENCE; i++) {
for (var index = 0; index < stack.length; ++index) {
var item = stack[index];
var op = _operators2['default'][item];
if (!op || op.precedence !== i) {
continue;
}
var _formatInfo = formatInfo(op);
var left = _formatInfo.left;
var right = _formatInfo.right;
var group = stack.splice(index - left, left + right + 1, []);
stack[index - left] = group;
for (var y = 0; y < i; y++) {
group = [group];
}
index -= right;
}
}
return stack;
});
/**
* Evaluates the given math expression.
* The expression is an array with an operator and arguments
*
* Example: evaluate([2, '+', 4]) == 6
*
* @param {Array} stack
* A single math expression
* @return {Number}
* Result of the expression
*/
var evaluate = function evaluate(stack) {
var _operators$op;
var op = findOperator(stack);
if (!op) {
return stack[0];
}
var _formatInfo2 = formatInfo(op);
var left = _formatInfo2.left;
var leftArguments = stack.slice(0, left),
rightArguments = stack.slice(left + 1);
return (_operators$op = _operators2['default'][op]).fn.apply(_operators$op, _toConsumableArray(leftArguments).concat(_toConsumableArray(rightArguments)));
};
/**
* Finds the first operator in an array and returns it
*
* @param {Array} arr
* The array to look for an operator in
* @return {Object}
* The operator object or null if no operator is found
*/
var findOperator = function findOperator(arr) {
var _iteratorNormalCompletion2 = true;
var _didIteratorError2 = false;
var _iteratorError2 = undefined;
try {
for (var _iterator2 = arr[Symbol.iterator](), _step2; !(_iteratorNormalCompletion2 = (_step2 = _iterator2.next()).done); _iteratorNormalCompletion2 = true) {
var o = _step2.value;
if (typeof o === 'string') {
return o;
}
}
} catch (err) {
_didIteratorError2 = true;
_iteratorError2 = err;
} finally {
try {
if (!_iteratorNormalCompletion2 && _iterator2['return']) {
_iterator2['return']();
}
} finally {
if (_didIteratorError2) {
throw _iteratorError2;
}
}
}
return null;
};
/**
* Replaces constants in a string with their values
*
* @param {String} expression
* The expression to replace constants in
* @return {String}
* The expression with constants replaced
*/
var replaceConstants = function replaceConstants(expression) {
return expression.replace(/[A-Z]*/g, function (a) {
var c = _constants2['default'][a];
if (!c) {
return a;
}
return typeof c === 'function' ? c() : c;
});
};
exports['default'] = Mathstring;
module.exports = exports['default'];

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'use strict';
Object.defineProperty(exports, '__esModule', {
value: true
});
/*
* Operators and Functions
* fn: function used to evaluate value
* format: the format using which arguments are parsed:
* 0 indicates an argument and 1 indicates the operator
* e.g: factorial is 01, add is 010, like 2!, 2+2
* precedence: determines which operators should be evaluated first
* the lower the value, the higher the precedence
*/
exports['default'] = {
'^': {
fn: function fn(a, b) {
return Math.pow(a, b);
},
format: '010',
precedence: 0
},
'*': {
fn: function fn(a, b) {
return a * b;
},
format: '010',
precedence: 1
},
'/': {
fn: function fn(a, b) {
return a / b;
},
format: '010',
precedence: 1
},
'%': {
fn: function fn(a, b) {
return a % b;
},
format: '010',
precedence: 1
},
'\\': {
fn: function fn(a, b) {
return Math.floor(a / b);
},
format: '010',
precedence: 1
},
'+': {
fn: function fn(a, b) {
return a + b;
},
format: '010',
precedence: 2
},
'-': {
fn: function fn(a, b) {
return a - b;
},
format: '010',
precedence: 2
},
'!': {
fn: function fn(a) {
var sum = 1;
for (var i = 0; i < a; ++i) {
sum *= i;
}
return sum;
},
format: '01',
precedence: 2
},
log: {
fn: Math.log,
format: '10',
precedence: -1
},
ln: {
fn: Math.log,
format: '10',
precedence: -1
},
lg: {
fn: function fn(a) {
return Math.log(a) / Math.log(2);
},
format: '10',
precedence: -1
},
sin: {
fn: Math.sin,
format: '10',
precedence: -1
},
cos: {
fn: Math.cos,
format: '10',
precedence: -1
},
tan: {
fn: Math.tan,
format: '10',
precedence: -1
},
cot: {
fn: Math.cot,
format: '10',
precedence: -1
}
};
module.exports = exports['default'];

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'use strict';
Object.defineProperty(exports, '__esModule', {
value: true
});
exports['default'] = function (string) {
var i = 0,
buffer = [];
return {
next: function next() {
buffer.push(string[i]);
if (i >= string.length) {
return null;
}return string[i++];
},
current: function current() {
return string[i - 1];
},
index: function index() {
return i - 1;
},
to: function to(n) {
var temp = '';
var dest = i + n;
for (i = i; i < dest; ++i) {
temp += [string[i]];
}
return temp;
},
drain: function drain() {
return buffer.splice(0, buffer.length);
},
replace: (function (_replace) {
function replace(_x, _x2, _x3) {
return _replace.apply(this, arguments);
}
replace.toString = function () {
return _replace.toString();
};
return replace;
})(function (start, end, replace) {
var temp = string.split('');
temp.splice(start, end, replace);
string = temp.join('');
i = i - (end - start);
}),
go: function go(n) {
i += n;
},
all: function all() {
return string;
}
};
};
module.exports = exports['default'];

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'use strict';
var _interopRequireWildcard = function (obj) { return obj && obj.__esModule ? obj : { 'default': obj }; };
var _expect = require('chai');
var _M = require('../index.js');
var _M2 = _interopRequireWildcard(_M);
describe('Basic math operators', function () {
it('should work for add +', function () {
_expect.expect(_M2['default'].solve('2+2')).to.equal(4);
});
it('should work for minus -', function () {
_expect.expect(_M2['default'].solve('15-3')).to.equal(12);
});
it('should work for divison /', function () {
_expect.expect(_M2['default'].solve('20/2')).to.equal(10);
});
it('should work for multiplication *', function () {
_expect.expect(_M2['default'].solve('6*3')).to.equal(18);
});
it('should work for power ^', function () {
_expect.expect(_M2['default'].solve('5^2')).to.equal(25);
});
it('should work for multi-digit numbers', function () {
_expect.expect(_M2['default'].solve('12+15')).to.equal(27);
});
});
describe('Precedence', function () {
it('Test case 1', function () {
_expect.expect(_M2['default'].solve('2+(2+1)*(1+1)^2')).to.equal(14);
});
it('Test case 2', function () {
_expect.expect(_M2['default'].solve('2+5*4/2-2')).to.equal(10);
});
it('Test case 3', function () {
_expect.expect(_M2['default'].solve('2+(5*4/2)-2')).to.equal(10);
});
it('Test case 4', function () {
_expect.expect(_M2['default'].solve('(2+2)^2+(5+1)*4+(2+(4/2)/2)')).to.equal(16 + 24 + 3);
});
});
describe('Functions', function () {
it('should work for with parantheses', function () {
_expect.expect(_M2['default'].solve('lg(4) * 5')).to.equal(10);
});
it('should work for without parantheses', function () {
_expect.expect(_M2['default'].solve('lg4 * 5')).to.equal(10);
});
});
describe('Constats', function () {
it('should work for constant values', function () {
_expect.expect(_M2['default'].solve('sin(PI/2)')).to.equal(1);
});
it('should work for functions as constants', function () {
_expect.expect(_M2['default'].solve('RAND')).to.not.equal(_M2['default'].solve('RAND'));
});
});

37
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'use strict';
var _interopRequireWildcard = function (obj) { return obj && obj.__esModule ? obj : { 'default': obj }; };
var _expect = require('chai');
var _M = require('../index.js');
var _M2 = _interopRequireWildcard(_M);
describe('Equations', function () {
it('should work with one variable', function () {
var equation = _M2['default'].equation('x+2');
_expect.expect(equation(2)).to.equal(4);
});
it('should work with multiple variables', function () {
var equation = _M2['default'].equation('x+y');
_expect.expect(equation(2, 4)).to.equal(6);
});
it('should work with multiple instances of the same variable', function () {
var equation = _M2['default'].equation('x*x');
_expect.expect(equation(4)).to.equal(16);
});
it('should only accept lowercase letters', function () {
var equation = _M2['default'].equation('X+2');
_expect.expect(equation).to['throw']();
});
it('Test case', function () {
var equation = _M2['default'].equation('2+x*(y+4)+z^2');
_expect.expect(equation(2, 4, 3)).to.equal(27);
});
});

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'use strict';
var _interopRequireWildcard = function (obj) { return obj && obj.__esModule ? obj : { 'default': obj }; };
var _expect = require('chai');
var _M = require('../index.js');
var _M2 = _interopRequireWildcard(_M);
describe('Basic math operators', function () {
it('should work for add +', function () {
_expect.expect(_M2['default'].solve('2+2')).to.equal(4);
});
it('should work for minus -', function () {
_expect.expect(_M2['default'].solve('15-3')).to.equal(12);
});
it('should work for divison /', function () {
_expect.expect(_M2['default'].solve('20/2')).to.equal(10);
});
it('should work for multiplication *', function () {
_expect.expect(_M2['default'].solve('6*3')).to.equal(18);
});
it('should work for power ^', function () {
_expect.expect(_M2['default'].solve('5^2')).to.equal(25);
});
it('should work for multi-digit numbers', function () {
_expect.expect(_M2['default'].solve('12+15')).to.equal(27);
});
});
describe('Precedence', function () {
it('Test case 1', function () {
_expect.expect(_M2['default'].solve('2+(2+1)*(1+1)^2')).to.equal(14);
});
it('Test case 2', function () {
_expect.expect(_M2['default'].solve('2+5*4/2-2')).to.equal(10);
});
it('Test case 3', function () {
_expect.expect(_M2['default'].solve('2+(5*4/2)-2')).to.equal(10);
});
it('Test case 4', function () {
_expect.expect(_M2['default'].solve('(2+2)^2+(5+1)*4+(2+(4/2)/2)')).to.equal(16 + 24 + 3);
});
});
describe('Functions', function () {
it('should work for with parantheses', function () {
_expect.expect(_M2['default'].solve('lg(4) * 5')).to.equal(10);
});
it('should work for without parantheses', function () {
_expect.expect(_M2['default'].solve('lg4 * 5')).to.equal(10);
});
});
describe('Constats', function () {
it('should work for constant values', function () {
_expect.expect(_M2['default'].solve('sin(PI/2)')).to.equal(1);
});
it('should work for functions as constants', function () {
_expect.expect(_M2['default'].solve('RAND')).to.not.equal(_M2['default'].solve('RAND'));
});
});

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export const parseFormat = function(a) {
const split = a.split('1');
return {
left: split[0].length,
right: split[1].length
};
};
export const isNumber = a => {
return !isNaN(+a);
};
export const parseNumbers = (a) => {
return a.map(b => {
if (isNumber(b)) {
return parseFloat(b);
}
if (Array.isArray(b)) {
return parseNumbers(b);
}
return b;
});
};
export const dive = (arr, n) => {
let result = arr;
for (let i = 0; i < n; ++i) {
result = result[result.length - 1];
}
return result;
};
export const deep = (arr, n, index = 0) => {
if (n < 2) {
return {arr, index};
}
let d = arr.reduce((a, b, i) => {
if (Array.isArray(b)) {
let {arr, index: x} = deep(b, n - 1, i),
merged = a.concat(arr);
index = x;
return merged;
}
return a;
}, []);
return {arr: d, index};
};
export const diveTo = (arr, indexes, replace) => {
let answer = [];
if (indexes.some(Array.isArray)) {
for (let index of indexes) {
answer.push(diveTo(arr, index, replace));
}
} else {
arr[indexes[0]] = replace;
return replace;
}
return answer;
};
export const flatten = (arr) => {
if (!Array.isArray(arr) || !arr.some(Array.isArray)) {
return arr;
}
return arr.reduce((a, b) => {
return a.concat(flatten(b));
}, []);
};
export const removeSymbols = string => {
return string.replace(/\W/g, '');
};

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import ReadStream from './readstream';
import operators from './operators';
import constants from './constats';
import * as _ from './helpers';
let Mathstring = {
/**
* Solves the given math expression, following these steps:
* 1. Replace constants in the expression
* 2. parse the expression, separating numbers and operators into
* an array
* 3. Sort the stack by operators' precedence, it actually groups the
* operator with it's arguments n-level deep
* 4. Apply parseFloat to numbers of the array
* 5. Solve groups recursively
*
* @param {String} expression
* The math expression to solve
* @return {Number}
* Result of the expression
*/
solve(expression) {
// replace constants with their values
expression = replaceConstants(expression);
let stack = parseExpression(expression);
stack = sortStack(stack);
stack = _.parseNumbers(stack);
stack = solveStack(stack);
return stack;
},
/**
* Creates an equation function which replaces variables
* in the given expression with the values specified in order,
* and solves the new expression
*
* Example:
* equation('x+y+z')(2, 5, 6) => solve('2+5+6')
*
* @param {String} expression
* The expression to create an equation for (containing variables)
* @return {Function}
* The function which replaces variables with values in order
* and solves the expression
*/
equation(expression) {
let stack = parseExpression(expression);
let variables = [];
stack.forEach(a => {
if (!_.isNumber(a) && !operators[a] && a === a.toLowerCase()) {
// grouped variables like (y) need to have their parantheses removed
variables.push(_.removeSymbols(a));
}
});
return function(...args) {
expression = expression.replace(/[a-z]*/g, a => {
let index = variables.indexOf(a);
if (index > -1) {
return args[index] || 0;
}
return a;
});
console.log(variables, expression);
return Mathstring.solve(expression);
};
}
};
const solveStack = stack => {
// $0(stack);
if (stack.some(Array.isArray)) {
stack = stack.map(group => {
if (!Array.isArray(group)) {
return group;
}
return solveStack(group);
});
return solveStack(stack);
} else {
return evaluate(stack);
}
};
const PRECEDENCES = Object.keys(operators).map(key => {
return operators[key].precedence;
});
const MAX_PRECEDENCE = Math.max(...PRECEDENCES);
const MIN_PRECEDENCE = Math.min(...PRECEDENCES);
/**
* Parses the given expression into an array of separated
* numbers and operators/functions.
* The result is passed to parseGroups
*
* @param {String} expression
* The expression to parse
* @return {Array}
* The parsed array
*/
const parseExpression = expression => {
let stream = new ReadStream(expression),
stack = [],
record = '';
// Create an array of separated numbers & operators
while (stream.next()) {
const cur = stream.current();
if (cur === ' ') {
continue;
}
// it's probably a function with a length more than one
if (!_.isNumber(cur) && !operators[cur] && cur !== '.') {
record += cur;
} else if (record.length) {
stack.push(record, cur);
record = '';
} else if (_.isNumber(stack[stack.length - 1]) &&
(_.isNumber(cur) || cur === '.')) {
stack[stack.length - 1] += cur;
} else {
stack.push(cur);
}
}
if (record.length) {
stack.push(record);
}
// $0(stack);
return parseGroups(stack);
};
/**
* Takes the parsed array from parseExpression and
* groups up expressions in parantheses in deep arrays
*
* Example: 2+(5+4) becomes [2, [5, '+', 4]]
*
* @param {Array} stack
* The parsed expression
* @return {Array}
* Grouped up expression
*/
const parseGroups = stack => {
// Parantheses become inner arrays which will then be processed first
let sub = 0;
return stack.reduce((a, b) => {
if (b[b.length - 1] === '(') {
if (b.length > 1) {
_.dive(a, sub).push(b.slice(0, -1), []);
} else {
_.dive(a, sub).push([]);
}
sub++;
} else if (b === ')') {
sub--;
} else {
_.dive(a, sub).push(b);
}
return a;
}, []);
};
/**
* Gives information about an operator's format
* including number of left and right arguments
*
* @param {String/Object} operator
* The operator object or operator name (e.g. +, -)
* @return {Object}
* An object including the count of left and right arguments
*/
const formatInfo = operator => {
let op = typeof operator === 'string' ? operators[operator]
: operator;
if (!op) {
return null;
}
const format = op.format.split('1'),
left = format[0].length,
right = format[1].length;
return { left, right };
};
/**
* Groups up operators and their arguments based on their precedence
* in deep arrays, the higher the priority, the deeper the group.
* This simplifies the evaluating process, the only thing to do is to
* evaluate from bottom up, evaluating deep groups first
*
* @param {Array} stack
* The parsed and grouped expression
* @return {Array}
* Grouped expression based on precedences
*/
const sortStack = stack => {
for (let [index, item] of stack.entries()) {
if (Array.isArray(item)) {
stack.splice(index, 1, sortStack(item));
}
}
for (let i = MIN_PRECEDENCE; i <= MAX_PRECEDENCE; i++) {
for (let index = 0; index < stack.length; ++index) {
let item = stack[index];
let op = operators[item];
if (!op || op.precedence !== i) {
continue;
}
const { left, right } = formatInfo(op);
let group = stack.splice(index - left, left + right + 1, []);
stack[index - left] = group;
for (let y = 0; y < i; y++) {
group = [group];
}
index -= right;
}
}
return stack;
};
/**
* Evaluates the given math expression.
* The expression is an array with an operator and arguments
*
* Example: evaluate([2, '+', 4]) == 6
*
* @param {Array} stack
* A single math expression
* @return {Number}
* Result of the expression
*/
const evaluate = stack => {
const op = findOperator(stack);
if (!op) {
return stack[0];
}
const { left } = formatInfo(op);
let leftArguments = stack.slice(0, left),
rightArguments = stack.slice(left + 1);
return operators[op].fn(...leftArguments, ...rightArguments);
};
/**
* Finds the first operator in an array and returns it
*
* @param {Array} arr
* The array to look for an operator in
* @return {Object}
* The operator object or null if no operator is found
*/
const findOperator = arr => {
for (let o of arr) {
if (typeof o === 'string') {
return o;
}
}
return null;
};
/**
* Replaces constants in a string with their values
*
* @param {String} expression
* The expression to replace constants in
* @return {String}
* The expression with constants replaced
*/
const replaceConstants = expression => {
return expression.replace(/[A-Z]*/g, (a) => {
let c = constants[a];
if (!c) {
return a;
}
return typeof c === 'function' ? c() : c;
});
};
export default Mathstring;

92
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/*
* Operators and Functions
* fn: function used to evaluate value
* format: the format using which arguments are parsed:
* 0 indicates an argument and 1 indicates the operator
* e.g: factorial is 01, add is 010, like 2!, 2+2
* precedence: determines which operators should be evaluated first
* the lower the value, the higher the precedence
*/
export default {
'^': {
fn: (a, b) => Math.pow(a, b),
format: '010',
precedence: 0
},
'*': {
fn: (a, b) => a * b,
format: '010',
precedence: 1
},
'/': {
fn: (a, b) => a / b,
format: '010',
precedence: 1
},
'%': {
fn: (a, b) => a % b,
format: '010',
precedence: 1
},
'\\': {
fn: (a, b) => Math.floor(a / b),
format: '010',
precedence: 1
},
'+': {
fn: (a, b) => a + b,
format: '010',
precedence: 2
},
'-': {
fn: (a, b) => a - b,
format: '010',
precedence: 2
},
'!': {
fn: (a) => {
let sum = 1;
for (var i = 0; i < a; ++i) {
sum *= i;
}
return sum;
},
format: '01',
precedence: 2
},
'log': {
fn: Math.log,
format: '10',
precedence: -1
},
'ln': {
fn: Math.log,
format: '10',
precedence: -1
},
'lg': {
fn: (a) => Math.log(a) / Math.log(2),
format: '10',
precedence: -1
},
'sin': {
fn: Math.sin,
format: '10',
precedence: -1
},
'cos': {
fn: Math.cos,
format: '10',
precedence: -1
},
'tan': {
fn: Math.tan,
format: '10',
precedence: -1
},
'cot': {
fn: Math.cot,
format: '10',
precedence: -1
}
};

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{
"name": "mathstring",
"version": "1.0.0",
"description": "",
"main": "dist/index.js",
"directories": {
"test": "tests"
},
"scripts": {
"test": "grunt test"
},
"keywords": [
"Math",
"JavaScript"
],
"author": "Mahdi Dibaiee",
"license": "MIT",
"devDependencies": {
"grunt": "^0.4.5",
"grunt-babel": "^5.0.0",
"grunt-contrib-watch": "^0.6.1",
"grunt-eslint": "^11.0.0",
"grunt-mocha-test": "^0.12.7",
"mocha": "^2.2.4"
}
}

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export default function(string) {
let i = 0, buffer = [];
return {
next() {
buffer.push(string[i]);
if (i >= string.length) return null;
return string[i++];
},
current() {
return string[i - 1];
},
index() {
return i - 1;
},
to(n) {
let temp = '';
const dest = i + n;
for (i = i; i < dest; ++i) {
temp += [string[i]];
}
return temp;
},
drain() {
return buffer.splice(0, buffer.length);
},
replace(start, end, replace) {
let temp = string.split('');
temp.splice(start, end, replace);
string = temp.join('');
i = i - (end - start);
},
go(n) {
i += n;
},
all() {
return string;
}
};
}

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import {expect} from 'chai';
import M from '../index.js';
describe('Equations', () => {
it('should work with one variable', () => {
let equation = M.equation('x+2');
expect(equation(2)).to.equal(4);
});
it('should work with multiple variables', () => {
let equation = M.equation('x+y');
expect(equation(2, 4)).to.equal(6);
});
it('should work with multiple instances of the same variable', () => {
let equation = M.equation('x*x');
expect(equation(4)).to.equal(16);
});
it('should only accept lowercase letters', () => {
let equation = M.equation('X+2');
expect(equation).to.throw();
});
it('Test case', () => {
let equation = M.equation('2+x*(y+4)+z^2');
expect(equation(2, 4, 3)).to.equal(27);
});
});

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import {expect} from 'chai';
import M from '../index.js';
describe('Basic math operators', () => {
it('should work for add +', () => {
expect(M.solve('2+2')).to.equal(4);
});
it('should work for minus -', () => {
expect(M.solve('15-3')).to.equal(12);
});
it('should work for divison /', () => {
expect(M.solve('20/2')).to.equal(10);
});
it('should work for multiplication *', () => {
expect(M.solve('6*3')).to.equal(18);
});
it('should work for power ^', () => {
expect(M.solve('5^2')).to.equal(25);
});
it('should work for multi-digit numbers', () => {
expect(M.solve('12+15')).to.equal(27);
});
});
describe('Precedence', () => {
it('Test case 1', () => {
expect(M.solve('2+(2+1)*(1+1)^2')).to.equal(14);
});
it('Test case 2', () => {
expect(M.solve('2+5*4/2-2')).to.equal(10);
});
it('Test case 3', () => {
expect(M.solve('2+(5*4/2)-2')).to.equal(10);
});
it('Test case 4', () => {
expect(M.solve('(2+2)^2+(5+1)*4+(2+(4/2)/2)')).to.equal(16 + 24 + 3);
});
});
describe('Functions', () => {
it('should work for with parantheses', () => {
expect(M.solve('lg(4) * 5')).to.equal(10);
});
it('should work for without parantheses', () => {
expect(M.solve('lg4 * 5')).to.equal(10);
});
});
describe('Constats', () => {
it('should work for constant values', () => {
expect(M.solve('sin(PI/2)')).to.equal(1);
});
it('should work for functions as constants', () => {
expect(M.solve('RAND')).to.not.equal(M.solve('RAND'));
});
});