A JavaScript full text search engine

This is an implementation of a "vector space model" with "Porter stemming", "double-metaphones", false boolean searches, field searching and field weighting. Basically it a full text search engine that has most of the fancy features the well known search engines libraries like Sphinx, Solr, Lucene, etc. The big difference is that it is written in JavaScript originally for use with Node.js.

Example

var NodeSearch = require('./../lib/node-search').NodeSearch;
var nStore = require('./lib/nstore');

// A simple data set to search over, feel free to use any data source, nstore uses JavaScript objects so it's simple
var db = nStore('data/example.db');

var search = new NodeSearch();
search.fieldWeights.title = 2; // Make one/or many of the document fields more important
var stream = db.stream();
stream.addListener('data', function (doc, meta) {
	search.index(meta.key,doc);
});

stream.addListener('end', function () { // when the indexing is finished
	search.query("meet !poultry", null, function (results) { // search and wait for the results
		results.forEach(function(result){
			db.get(result.key, function (err, doc, meta) { 
				if(err) throw err;
				console.log(result.key+" "+doc.title +" "+doc.body +" "+  result.rank);
			});
		});
	});
});

This code is based on idea and code from

http://blog.josephwilk.net/projects/building-a-vector-space-search-engine-in-python.html
http://github.com/maritz/js-double-metaphone/raw/master/double-metaphone.js
http://yeti-witch.googlecode.com/svn/trunk/lib/porter-stemmer.js
http://www.koders.com/javascript/fidACD9DF0C1463CFC127D8C8B767B77122F3FC7331.aspx
http://playnice.ly/blog/2010/05/05/a-fast-fuzzy-full-text-index-using-redis/
http://users.telenet.be/paul.larmuseau/SVD.htm
http://gist.github.com/389875
http://sylvester.jcoglan.com/api/matrix
http://www.uni-bonn.de/~manfear/matrixcalc.php
http://www.sphinxsearch.com/docs/manual-1.10.html#boolean-syntax
http://stackoverflow.com/questions/90580/word-frequency-algorithm-for-natural-language-processing
http://stackoverflow.com/questions/2699646/how-to-get-logical-parts-of-a-sentence-with-java

Things that it doesn't currently do but would like to look into:

Phrase based searches, everything is word based, combonations of words are not currently supported
Exact matches, all words are converted to stemmed metaphones so "ponies" is indexed as the sound of "pony".
Date based searches or other meta data with additional logic are not currently supported
tf-idf based ranking, currently using a term count
http://blog.josephwilk.net/projects/latent-semantic-analysis-in-python.html
http://en.wikipedia.org/wiki/Lanczos_method
http://en.wikipedia.org/wiki/Latent_semantic_indexing
http://en.wikipedia.org/wiki/Probabilistic_latent_semantic_analysis
http://en.wikipedia.org/wiki/Latent_Dirichlet_allocation
http://en.wikipedia.org/wiki/Part-of-speech_tagging

License

(The MIT License)

Copyright (c) 2009 Motion & Color <Tyler Larson>

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the 'Software'), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.