@metacorp/trie

Wade

Blazing fast 1kb search

https://jsperf.com/metacorp-trie-search https://jsperf.com/metacorp-trie-init

Installation

NPM

npm install wade

CDN

<script src="https://unpkg.com/wade"></script>

Usage

Initialize Wade with an array of data.

const search = Wade(["Apple", "Lemon", "Orange", "Tomato"]);

Now you can search for a query within the data, and Wade will return results. Each result will include the index of the item in the data it corresponds to along with a score depending on the relevance of the query to the result.

search("App");
/*
[{
  index: 0,
  score: 1.25
}]
*/

Combined with libraries like Moon, you can create a real-time search.

Loading/Saving Data

To save data as an object, use Wade.save on your search function, and then use these later when initializing Wade.

For example:

// Create the initial search function
const search = Wade(["Apple", "Lemon", "Orange", "Tomato"]);
const instance = Wade.save(search);

// Save `instance`

Later, you can get the same search function without having Wade recreate an index every time by doing:

// Retrieve `instance`, then
const search = Wade(instance);

instance can be saved to a file using using JSON.stringify() and loaded with JSON.parse().

Processors

Wade uses a set of processors to preprocess data and search queries. By default, these will:

• Make everything lowercase
• Remove punctuation
• Remove stop words

A process consists of different functions that process a string and modify it in some way, and return the transformed string.

You can easily modify the processors as they are available in Wade.config.processors, for example:

// Don't preprocess at all
Wade.config.processors = [];

// Add custom processor to remove periods
Wade.config.processors.push(function(str) {
  return str.replace(/\./g, "");
});

All functions will be executed in the order of the array (0-n) and they will be used on each document in the data.

The stop words can be configured to include any words you like, and you can access the array of stop words by using:

Wade.config.stopWords = [/* array of stop words */];

The punctuation regular expression used to remove punctuation can be configured with:

Wade.config.punctuationRE = /[.!]/g; // should contain punctuation to remove

Algorithm

First, an index is generated from the data. When performing a search, the following happens:

• The search query is processed.
• The search query is tokenized into terms.
• Each term except the last is searched for exactly and scores for each item in the data are updated according to the relevance of the term to the data.
• The last keyword is treated as a prefix, and Wade performs a depth-first search and updates the score for all data prefixed with this term using the relevance weight for the term. This allows for searching as a user types.

In-depth explanations of the algorithm are available on the blog post and pdf.

Support

Support Wade on Patreon to help sustain the development of the project. The maker of the project works on open source for free. If you or your company depend on this project, then it makes sense to donate to ensure that the project is maintained.

License

Licensed under the MIT License by Kabir Shah