## jsep: A Tiny JavaScript Expression Parser
[jsep](https://ericsmekens.github.io/jsep/) is a simple expression parser written in JavaScript. It can parse JavaScript expressions but not operations. The difference between expressions and operations is akin to the difference between a cell in an Excel spreadsheet vs. a proper JavaScript program.

### Why jsep?
I wanted a lightweight, tiny parser to be included in one of my other libraries. [esprima](http://esprima.org/) and other parsers are great, but had more power than I need and were *way* too large to be included in a library that I wanted to keep relatively small.

jsep's output is almost identical to [esprima's](http://esprima.org/doc/index.html#ast), which is in turn based on [SpiderMonkey's](https://developer.mozilla.org/en-US/docs/SpiderMonkey/Parser_API).

### Custom Build
First, install [Grunt](http://gruntjs.com/). While in the jsep project directory, run:

```bash
npm install .
grunt
```

The jsep built files will be in the build/ directory.

### Usage
#### Client-side
```javascript
<script src="/PATH/TO/jsep.min.js" type="text/javascript"></script>
...
var parse_tree = jsep("1 + 1");
```
#### Node.JS
First, run `npm install jsep`. Then, in your source file:
```javascript
var jsep = require("jsep");
var parse_tree = jsep("1 + 1");
```
#### Custom Operators
```javascript
// Add a custom ^ binary operator with precedence 10
jsep.addBinaryOp("^", 10);

// Add a custom @ unary operator
jsep.addUnaryOp('@');

// Remove a binary operator
jsep.removeBinaryOp(">>>");

// Remove a unary operator
jsep.removeUnaryOp("~");
```

### License
jsep is under the MIT license. See LICENSE file.

### Thanks
Some parts of the latest version of jsep were adapted from the esprima parser.