RPN calculator

Reverse Polish notation (RPN) is a mathematical notation in which every operator follows all of its operands, in contrast to Polish notation, which puts the operator in the prefix position. It is also known as postfix notation and is parenthesis-free as long as operator arities are fixed.

Installation

npm install rpn-calculator

Usage

var calculator = require('rpn-calculator');

// 1 + 2 = 3
calculator('1 2 +'); // 3

// 1 + 2 - 3 = 0
calculator('1 2 + 3 -'); // 0

// (1 + 2) * 3 = 9
calculator('1 2 + 3 *'); // 9

Supports scientific notation:

calculator('1e2 1e-2 +'); // 100.01

Available operators

All operators replicate the default JavaScript behavior except min and max which are limited to 2 arguments to satisfy the default arity of RPN calculator.

operator | operation | example :-------:|------------------------------|------------ + | addition | 1 2 + = 3 - | subtraction | 1 2 - = -1 * | multiplication | 2 3 * = 6 / | division | 7 2 / = 3.5 % | modulus | 12 5 % = 2 pow | exponentiation | 7 2 pow = 49 max | maximum of two | 1 2 max = 2 min | minimum of two | 1 2 min = 1 & | bitwise AND | 15 9 & = 9 | | bitwise OR | 15 9 | = 15 ^ | bitwise XOR | 15 9 ^ = 6 << | left shift | 9 2 << = 36 >> | sign-propagating right shift | 9 2 >> = 2 >>> | zero-filled right shift | 9 2 >>> = 2

Tests

npm install && npm test

License

http://opensource.org/licenses/mit-license.html