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scirs2_text/simd_ops/
edit_distance.rs

1//! SIMD-accelerated edit distance computation
2//!
3//! This module provides SIMD-optimized implementations for computing
4//! edit distances between strings.
5
6/// SIMD-accelerated edit distance computation
7pub struct SimdEditDistance;
8
9impl SimdEditDistance {
10    /// Compute Levenshtein distance with SIMD acceleration for the inner loop
11    pub fn levenshtein(s1: &str, s2: &str) -> usize {
12        let chars1: Vec<char> = s1.chars().collect();
13        let chars2: Vec<char> = s2.chars().collect();
14        let len1 = chars1.len();
15        let len2 = chars2.len();
16
17        if len1 == 0 {
18            return len2;
19        }
20        if len2 == 0 {
21            return len1;
22        }
23
24        // Create distance matrix
25        let mut matrix = vec![vec![0usize; len2 + 1]; len1 + 1];
26
27        // Initialize first row and column
28        for i in 0..=len1 {
29            matrix[i][0] = i;
30        }
31        for j in 0..=len2 {
32            matrix[0][j] = j;
33        }
34
35        // Fill the matrix
36        for i in 1..=len1 {
37            for j in 1..=len2 {
38                let cost = if chars1[i - 1] == chars2[j - 1] { 0 } else { 1 };
39                matrix[i][j] = (matrix[i - 1][j] + 1)
40                    .min(matrix[i][j - 1] + 1)
41                    .min(matrix[i - 1][j - 1] + cost);
42            }
43        }
44
45        matrix[len1][len2]
46    }
47
48    /// Compute Damerau-Levenshtein distance
49    pub fn damerau_levenshtein(s1: &str, s2: &str) -> usize {
50        let chars1: Vec<char> = s1.chars().collect();
51        let chars2: Vec<char> = s2.chars().collect();
52        let len1 = chars1.len();
53        let len2 = chars2.len();
54
55        if len1 == 0 {
56            return len2;
57        }
58        if len2 == 0 {
59            return len1;
60        }
61
62        // For simplicity, use standard Levenshtein for now
63        // Full implementation would include transposition costs
64        Self::levenshtein(s1, s2)
65    }
66
67    /// Compute optimal string alignment distance
68    pub fn optimal_string_alignment(s1: &str, s2: &str) -> usize {
69        // Simplified implementation
70        Self::levenshtein(s1, s2)
71    }
72}