morph-expressions

An extremely efficient and flexible parser for Math or Logical expression using Javascript. It has all the basic functions supported with extensive support for new functions, variable etc.

Install

$ npm install morph-expressions

Usage

import Parser from 'morph-expressions';
const parser = new Parser();
 
const compiled = parser.parse('1 + 1');
compiled.eval(); // returns 2

You can also specify scope:

const compiled = parser.parse('x + 1 - y == 0');
compiled.identifiers; // ['x', 'y'] - returns list of identifiers, which used in expression
compiled.eval({ x: 2, y: 3 }); // returns true
 
//Or
 
parser.parseAndEval('x + 1 - y == 0', { x: 2, y: 3 });  // returns true
parser.parseAndEval('foo.bar[1] == 5', { foo: { bar: [4, 5, 6] } });  // returns true

For register the custom function or computed properties

parser.registerFunction('sqr', value => value * value);
parser.registerProperty('foo', scope => 'bar');
 
parser.parseAndEval('sqr(sqr(x))', { x: 2 });  // returns 16
parser.parseAndEval('foo', { x: 2 });  // returns 'bar'

Test

To execute tests for the library, install the project dependencies once:

npm install

Then, the tests can be executed:

npm test