mystor / mathparser

A parser for simple mathematical expressions.

MathParser

A basic library for parsing simple mathematical expressions, and evaluating them.

Made for maxbittker's Mojulo.

Usage

Include the mathparser.js file in your html (<script src="mathparser.js"></script>).

If you are using commonjs, you can also use var mathparser = require('./mathparser'); to require the math parser, but mathparser isn't on npm (and probably never will be).

Parsing an expression will produce a function:

var fun = mathparser.parse('x * y^2 + 5 / sin(x)');

You can then use that function

var exposedFunctions = {
  sin: Math.sin,
  cos: Math.cos,
  rand: Math.random
};

var exposedVars = {
  x: 10,
  y: 20,
  pi: Math.PI
};

var result = fun(exposedFunctions, exposedVars); // 3990.8091802

Building

MathParser is implemented as a single jison file. You compile it using (unsurprisingly) jison.

$ jison mathparser.jison