efrt

trie-based compression of word-data

npm i efrt

efrt is a prefix/suffix trie optimised for compression of english words.

it is based on mckoss/lookups by Mike Koss and bits.js by Steve Hanov

• squeeze a list of words into a very compact form
• reduce filesize/bandwidth a bunch
• ensure unpacking overhead is negligible
• word-lookups are critical-path

By doing the fancy stuff ahead-of-time, efrt lets you ship much bigger word-lists to the client-side, without much hassle.

var efrt = require('efrt')
var words = [
  'coolage',
  'cool',
  'cool cat',
  'cool.com',
  'coolamungo'
];

//pack these words as tightly as possible
var compressed = efrt.pack(words);
//cool0;! cat,.com,a0;ge,mungo

//create a lookup-trie
var trie = efrt.unpack(compressed);

//hit it!
console.log(trie.has('cool'));//true
console.log(trie.has('miles davis'));//false

Demo!

the words you input should be pretty normalized. Spaces and unicode are good, but numbers, case-sensitivity, and some punctuation are not (yet) supported.

IE9+

<script src="https://unpkg.com/efrt@latest/builds/efrt.min.js"></script>
<script>
  var smaller=efrt.pack(['larry','curly','moe'])
  var trie=efrt.unpack(smaller)
  console.log(trie.has('moe'))
</script>

if you're doing the second step in the client, you can load just the unpack-half of the library(~3k):

<script src="https://unpkg.com/efrt@latest/builds/efrt-unpack.min.js"></script>
<script>
  var trie=unpack(compressedStuff);
  trie.has('miles davis');
</script>