maprereduce

Simple mapreduce implementation with additional rereduce step and filtering. Can be use in node or in browser (AMD or standalone).

Install

To install current release from npm, run:

npm install maprereduce

Use

You can load this module, like every standard npm module:

var maprereduce = require('maprereduce');

And then you need to implement 3 functions:

var mr = new maprereduce(function(item) {
    // Your map function
}, function(result) {
    // Your reduce function
}, function(item1, item2) {
    // Your rereduce function
});

To feed maprereduce with data, use:

mr.feed(data); // data is Array

And to get results (at any time), use:

var result = mr.result;

Filtering values

Normally the value returned by map function is used as a key in resulting object. If the returned value is === undefined or null, the key and all releated values will be filtered and will not occur in resulting object, e.g.

var map = function(item) {
    return item.length > 2 ? item.length : null; // So all items shorter than 3 will be filtered
}