string/
string.rs

1use matchete::{Matcher, Custom};
2
3// Simple Levenshtein-like metric implementation
4struct SimpleLevenshteinMetric;
5
6impl SimpleLevenshteinMetric {
7    fn levenshtein_distance(a: &str, b: &str) -> usize {
8        let len_a = a.len();
9        let len_b = b.len();
10
11        if len_a == 0 { return len_b; }
12        if len_b == 0 { return len_a; }
13
14        let mut matrix = vec![vec![0; len_b + 1]; len_a + 1];
15
16        for i in 0..=len_a { matrix[i][0] = i; }
17        for j in 0..=len_b { matrix[0][j] = j; }
18
19        for i in 1..=len_a {
20            for j in 1..=len_b {
21                let cost = if a.chars().nth(i - 1) == b.chars().nth(j - 1) { 0 } else { 1 };
22                matrix[i][j] = (matrix[i - 1][j] + 1)
23                    .min(matrix[i][j - 1] + 1)
24                    .min(matrix[i - 1][j - 1] + cost);
25            }
26        }
27
28        matrix[len_a][len_b]
29    }
30}
31
32fn main() {
33    // Create a custom similarity metric for strings
34    let levenshtein_metric = Custom::new(|query: &String, candidate: &String| {
35        let distance = SimpleLevenshteinMetric::levenshtein_distance(query, candidate);
36        let max_len = query.len().max(candidate.len());
37        if max_len == 0 { 1.0 } else { 1.0 - (distance as f64 / max_len as f64) }
38    });
39
40    // Create a matcher with the custom metric
41    let matcher = Matcher::<String, String>::new()
42        .add(levenshtein_metric, 1.0)
43        .threshold(0.6);
44
45    // Define the query and candidate strings
46    let query = String::from("hello");
47    let candidates = vec![
48        String::from("hello"),
49        String::from("helo"),
50        String::from("world"),
51    ];
52
53    // Find the best match
54    println!("Basic String Matching Example");
55    println!("============================");
56    if let Some(result) = matcher.best(&query, &candidates) {
57        println!(
58            "Best match found:\n  Score: {:.2}\n  Candidate: {}\n  Exact: {}",
59            result.score, result.candidate, result.exact
60        );
61    } else {
62        println!("No match found above threshold");
63    }
64}
string/string.rs

string/
string.rs
