whatlang 0.6.0

Natural language detection library. Identifies language of a given text.
Documentation

Whatlang

Build Status License Documentation online demo

Natural language detection for Rust with focus on simplicity and performance.

Features

  • Supports 83 languages
  • 100% written in Rust
  • Lightweight, fast and simple
  • Recognizes not only a language, but also a script (Latin, Cyrillic, etc)
  • Provides reliability information

Get started

Add to you Cargo.toml:

[dependencies]

whatlang = "0.6.0"

Example:

extern crate whatlang;

use whatlang::{detect, Lang, Script};

fn main() {
    let text = "Ĉu vi ne volas eklerni Esperanton? Bonvolu! Estas unu de la plej bonaj aferoj!";

    let info = detect(text).unwrap();
    assert_eq!(info.lang(), Lang::Epo);
    assert_eq!(info.script(), Script::Latin);
    assert_eq!(info.confidence(), 1.0);
    assert!(info.is_reliable());
}

For more details (e.g. how to blacklist some languages) please check the documentation.

Requirements

The latest whatlang library works with rust 1.19.0 or higher.

How does it work?

How does the language recognition work?

The algorithm is based on the trigram language models, which is a particular case of n-grams. To understand the idea, please check the original whitepaper Cavnar and Trenkle '94: N-Gram-Based Text Categorization'.

How is_reliable calculated?

It is based on the following factors:

  • How many unique trigrams are in the given text
  • How big is the difference between the first and the second(not returned) detected languages? This metric is called rate in the code base.

Therefore, it can be presented as 2d space with threshold functions, that splits it into "Reliable" and "Not reliable" areas. This function is a hyperbola and it looks like the following one:

For more details, please check a blog article Introduction to Rust Whatlang Library and Natural Language Identification Algorithms.

Running benchmarks

This is mostly useful to test performance optimizations.

cargo bench

Ports and clones

Derivation

Whatlang is a derivative work from Franc (JavaScript, MIT) by Titus Wormer.

License

MIT © Sergey Potapov

Contributors

  • greyblake Potapov Sergey - creator, maintainer.
  • Dr-Emann Zachary Dremann - optimization and improvements