rpn-calculator
Version:
Reverse Polish notation calculator
67 lines (49 loc) • 2.35 kB
Markdown
RPN calculator
==============
[Reverse Polish notation (RPN)](http://en.wikipedia.org/wiki/Reverse_Polish_notation) is a mathematical notation in which every operator follows all of its operands, in contrast to [Polish notation](http://en.wikipedia.org/wiki/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.
[](https://travis-ci.org/olegskl/rpn-calculator)
[](https://codeclimate.com/github/olegskl/rpn-calculator)
[](https://coveralls.io/r/olegskl/rpn-calculator)
## Installation
```Bash
npm install rpn-calculator
```
## Usage
```JavaScript
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:
```JavaScript
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
```Bash
npm install && npm test
```
## License
http://opensource.org/licenses/mit-license.html