Crate rust_fuzzy_search

This crate implements Fuzzy Searching with trigrams

Fuzzy searching allows to compare strings by similarity rather than by equality:
Similar strings will get a high score (close to 1.0f32) while dissimilar strings will get a lower score (closer to 0.0f32).

Fuzzy searching tolerates changes in word order:
ex. "John Dep" and "Dep John" will get a high score.

The crate exposes 5 main functions:

• fuzzy_compare will take 2 strings and return a score representing how similar those strings are.
• fuzzy_search applies fuzzy_compare to a list of strings and returns a list of tuples: (word, score).
• fuzzy_search_sorted is similar to fuzzy_search but orders the output in descending order.
• fuzzy_search_threshold will take an additional f32 as input and returns only tuples with score greater than the threshold.
• fuzzy_search_best_n will take an additional usize arguments and returns the first n tuples.

The Algorithm used is taken from : https://dev.to/kaleman15/fuzzy-searching-with-postgresql-97o

Basic idea:

1. From both strings extracts all groups of 3 adjacent letters.
   ("House" becomes [' H', ' Ho', 'Hou', 'ous', 'use', 'se ']).
   Note the 2 spaces added to the head of the string and the one on the tail, used to make the algorithm work on zero length words.

2. Then counts the number of trigrams of the first words that are also present on the second word and divide by the number of trigrams of the first word.

Example: Comparing 2 strings

fn test () {
   use rust_fuzzy_search::fuzzy_compare;
   let score : f32 = fuzzy_compare("kolbasobulko", "kolbasobulko");
   println!("score = {:?}", score);
}

Example: Comparing a string with a list of strings and retrieving only the best matches

fn test() {
    use rust_fuzzy_search::fuzzy_search_best_n;
    let s = "bulko";
    let list : Vec<&str> = vec![
        "kolbasobulko",
        "sandviĉo",
        "ŝatas",
        "domo",
        "emuo",
        "fabo",
        "fazano"
    ];
    let n : usize = 3;
    let res : Vec<(&str, f32)> = fuzzy_search_best_n(s,&list, n);
    for (_word, score) in res {
        println!("{:?}",score)
    }
}

Example: if you have a Vec of Strings you need to convert it to a list of &str

fn works_with_strings() {
    use rust_fuzzy_search::fuzzy_search;
    let s = String::from("varma");
    let list: Vec<String> = vec![String::from("varma vetero"), String::from("varma ĉokolado")];
    fuzzy_search(&s, &list.iter().map(String::as_ref).collect::<Vec<&str>>());
}

Functions

fuzzy_compare

Use this function to compare 2 strings.

fuzzy_search

Use this function to compare a string (&str) with all elements of a list.

fuzzy_search_best_n

This function is similar to fuzzy_search_sorted but keeps only the n best items, those with a better match.

fuzzy_search_sorted

This function is similar to fuzzy_search but sorts the result in descending order (the best matches are placed at the beginning).

fuzzy_search_threshold

This function is similar to fuzzy_search but filters out element with a score lower than the specified one.