# strsim-rs [![Build Status](https://travis-ci.org/dguo/strsim-rs.svg?branch=master)](https://travis-ci.org/dguo/strsim-rs) [![Crates.io](https://img.shields.io/crates/v/strsim.svg)](https://crates.io/crates/strsim)
Rust implementations of [string similarity metrics]. Should compile cleanly on both the nightly and 1.0 versions of Rust. Includes:
- [Hamming]
- [Levenshtein] and [Damerau-Levenshtein]
- [Jaro and Jaro-Winkler] - this implementation of Jaro-Winkler does not limit the common prefix length
### Installation
```toml
# Cargo.toml
[dependencies]
strsim = "0.4.0"
```
### Usage
```rust
extern crate strsim;
use strsim::{hamming, levenshtein, damerau_levenshtein, jaro, jaro_winkler,
levenshtein_against_vec, damerau_levenshtein_against_vec,
jaro_against_vec, jaro_winkler_against_vec};
fn main() {
match hamming("hamming", "hammers") {
Ok(distance) => assert_eq!(3, distance),
Err(why) => panic!("{:?}", why)
}
assert_eq!(3, levenshtein("kitten", "sitting"));
assert_eq!(1, damerau_levenshtein("specter", "spectre"));
assert!((0.392 - jaro("Friedrich Nietzsche", "Jean-Paul Sartre")).abs() <
0.001);
assert!((0.911 - jaro_winkler("cheeseburger", "cheese fries")).abs() <
0.001);
// get vectors of values back
let v = vec!["test", "test1", "test12", "test123", "", "tset"];
assert_eq!(levenshtein_against_vec("test", &v),
vec![0, 1, 2, 3, 4, 2]);
assert_eq!(damerau_levenshtein_against_vec("test", &v),
vec![0, 1, 2, 3, 4, 1]);
let jaro_distances = jaro_against_vec("test", &v);
let jaro_expected = vec![1.0, 0.933333, 0.888889, 0.857143, 0.0, 0.916667];
let jaro_delta: f64 = jaro_distances.iter()
.zip(jaro_expected.iter())
.map(|(x, y)| (x - y).abs() as f64)
.fold(0.0, |x, y| x + y as f64);
assert!(jaro_delta < 0.0001);
let jaro_winkler_distances = jaro_winkler_against_vec("test", &v);
let jaro_winkler_expected = vec![1.0, 0.96, 0.933333, 0.914286, 0.0, 0.925];
let jaro_winkler_delta = jaro_winkler_distances.iter()
.zip(jaro_winkler_expected.iter())
.map(|(x, y)| (x - y).abs() as f64)
.fold(0.0, |x, y| x + y as f64);
assert!(jaro_winkler_delta < 0.0001);
}
```
### License
MIT
[string similarity metrics]:http://en.wikipedia.org/wiki/String_metric
[Damerau-Levenshtein]:http://en.wikipedia.org/wiki/Damerau%E2%80%93Levenshtein_distance
[Jaro and Jaro-Winkler]:http://en.wikipedia.org/wiki/Jaro%E2%80%93Winkler_distance
[Levenshtein]:http://en.wikipedia.org/wiki/Levenshtein_distance
[Hamming]:http://en.wikipedia.org/wiki/Hamming_distance