This commit is contained in:
Mahdi Dibaiee 2015-06-18 17:32:28 +04:30
parent adb74a6f31
commit d360065e1b
2 changed files with 89 additions and 16 deletions

View File

@ -247,10 +247,14 @@ var Equation = {
*/ */
equation: function equation(expression) { equation: function equation(expression) {
var stack = parseExpression(expression); var stack = parseExpression(expression);
console.log(stack);
var variables = []; var variables = [];
stack.forEach(function (a) { stack.forEach(function varCheck(a) {
if (typeof a === 'string' && !_.isNumber(a) && !_operators2['default'][a] && a === a.toLowerCase()) { if (Array.isArray(a)) {
return a.forEach(varCheck);
}
if (isVariable(a)) {
// grouped variables like (y) need to have their parantheses removed // grouped variables like (y) need to have their parantheses removed
variables.push(_.removeSymbols(a)); variables.push(_.removeSymbols(a));
} }
@ -261,15 +265,30 @@ var Equation = {
args[_key] = arguments[_key]; args[_key] = arguments[_key];
} }
expression = expression.replace(/[a-z]*/g, function (a) { stack.forEach(function varCheck(a, i, arr) {
if (Array.isArray(a)) {
return a.forEach(varCheck);
}
var index = variables.indexOf(a); var index = variables.indexOf(a);
if (index > -1) { if (index > -1) {
return args[index] || 0; // grouped variables like (y) need to have their parantheses removed
arr[i] = args[index];
} }
return a;
}); });
return Equation.solve(expression); stack = sortStack(stack);
stack = _.parseNumbers(stack);
stack = solveStack(stack);
// expression = expression.replace(/[a-z]*/g, a => {
// let index = variables.indexOf(a);
// if (index > -1) {
// return args[index] || 0;
// }
// return a;
// });
return stack;
}; };
}, },
@ -327,33 +346,50 @@ var MIN_PRECEDENCE = Math.min.apply(Math, _toConsumableArray(PRECEDENCES));
var parseExpression = function parseExpression(expression) { var parseExpression = function parseExpression(expression) {
var stream = new _ReadStream2['default'](expression), var stream = new _ReadStream2['default'](expression),
stack = [], stack = [],
record = ''; record = '',
cur = undefined,
past = undefined;
// Create an array of separated numbers & operators // Create an array of separated numbers & operators
while (stream.next()) { while (stream.next()) {
var cur = stream.current(), cur = stream.current();
past = stack.length - 1; past = stack.length - 1;
if (cur === ' ') { if (cur === ' ') {
continue; continue;
} }
// it's probably a function with a length more than one // it's probably a function with a length more than one
if (!_.isNumber(cur) && !_operators2['default'][cur] && cur !== '.') { if (!_.isNumber(cur) && !_operators2['default'][cur] && cur !== '.' && cur !== '(' && cur !== ')') {
record += cur; record += cur;
} else if (record.length) { } else if (record.length) {
var beforeRecord = past - (record.length - 1);
if (isVariable(record) && _.isNumber(stack[beforeRecord])) {
stack.push('*');
}
stack.push(record, cur); stack.push(record, cur);
record = ''; record = '';
} else if (_.isNumber(stack[stack.length - 1]) && (_.isNumber(cur) || cur === '.')) {
stack[stack.length - 1] += cur; // numbers and decimals
} else if (_.isNumber(stack[past]) && (_.isNumber(cur) || cur === '.')) {
stack[past] += cur;
// negation sign
} else if (stack[past] === '-') { } else if (stack[past] === '-') {
var beforeSign = stack[stack.length - 2]; var beforeSign = stack[past - 1];
// 2 / -5 is OK, pass
if (_operators2['default'][beforeSign]) { if (_operators2['default'][beforeSign]) {
stack[past] += cur; stack[past] += cur;
// (2+1) - 5 becomes (2+1) + -5
} else if (beforeSign === ')') { } else if (beforeSign === ')') {
stack[past] = '+'; stack[past] = '+';
stack.push('-' + cur); stack.push('-' + cur);
// 2 - 5 is also OK, pass
} else if (_.isNumber(beforeSign)) { } else if (_.isNumber(beforeSign)) {
stack.push(cur); stack.push(cur);
} else { } else {
@ -364,6 +400,10 @@ var parseExpression = function parseExpression(expression) {
} }
} }
if (record.length) { if (record.length) {
var beforeRecord = past - (record.length - 1);
if (isVariable(record) && _.isNumber(stack[beforeRecord])) {
stack.push('*');
}
stack.push(record); stack.push(record);
} }
@ -530,7 +570,7 @@ var evaluate = function evaluate(stack) {
var leftArguments = stack.slice(0, left), var leftArguments = stack.slice(0, left),
rightArguments = stack.slice(left + 1); rightArguments = stack.slice(left + 1);
return (_operators$op = _operators2['default'][op]).fn.apply(_operators$op, _toConsumableArray(leftArguments).concat(_toConsumableArray(rightArguments))); return fixFloat((_operators$op = _operators2['default'][op]).fn.apply(_operators$op, _toConsumableArray(leftArguments).concat(_toConsumableArray(rightArguments))));
}; };
/** /**
@ -590,8 +630,31 @@ var replaceConstants = function replaceConstants(expression) {
}); });
}; };
/**
* Fixes JavaScript's floating point precisions - Issue #5
*
* @param {Number} number
* The number to fix
* @return {Number}
* Fixed number
*/
var fixFloat = function fixFloat(number) {
return +number.toFixed(15);
};
/**
* Recognizes variables such as x, y, z
* @param {String} a
* The string to check for
* @return {Boolean}
* true if variable, else false
*/
var isVariable = function isVariable(a) {
return typeof a === 'string' && !_.isNumber(a) && !_operators2['default'][a] && a === a.toLowerCase();
};
exports.isVariable = isVariable;
exports['default'] = Equation; exports['default'] = Equation;
module.exports = exports['default'];
},{"./constants":1,"./helpers":2,"./operators":4,"./readstream":5}],4:[function(require,module,exports){ },{"./constants":1,"./helpers":2,"./operators":4,"./readstream":5}],4:[function(require,module,exports){
'use strict'; 'use strict';
@ -704,6 +767,16 @@ exports['default'] = {
fn: Math.cot, fn: Math.cot,
format: '10', format: '10',
precedence: -1 precedence: -1
},
round: {
fn: Math.round,
format: '10',
precedence: -1
},
floor: {
fn: Math.floor,
format: '10',
precedence: -1
} }
}; };
module.exports = exports['default']; module.exports = exports['default'];

2
equation.min.js vendored

File diff suppressed because one or more lines are too long