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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-17 12:02:58 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-17 12:02:58 +0000
commit698f8c2f01ea549d77d7dc3338a12e04c11057b9 (patch)
tree173a775858bd501c378080a10dca74132f05bc50 /vendor/gsgdt/src/levenshtein.rs
parentInitial commit. (diff)
downloadrustc-698f8c2f01ea549d77d7dc3338a12e04c11057b9.tar.xz
rustc-698f8c2f01ea549d77d7dc3338a12e04c11057b9.zip
Adding upstream version 1.64.0+dfsg1.upstream/1.64.0+dfsg1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'vendor/gsgdt/src/levenshtein.rs')
-rw-r--r--vendor/gsgdt/src/levenshtein.rs70
1 files changed, 70 insertions, 0 deletions
diff --git a/vendor/gsgdt/src/levenshtein.rs b/vendor/gsgdt/src/levenshtein.rs
new file mode 100644
index 000000000..8acfefc83
--- /dev/null
+++ b/vendor/gsgdt/src/levenshtein.rs
@@ -0,0 +1,70 @@
+use std::cmp::min;
+
+/// Calculate the levenshtein distance between two strings.
+pub(crate) fn distance(s1: &str, s2: &str) -> usize {
+ let v1: Vec<char> = s1.chars().collect();
+ let v2: Vec<char> = s2.chars().collect();
+
+ let l_v1 = v1.len();
+ let l_v2 = v2.len();
+
+ if l_v1 == 0 {
+ return l_v2;
+ }
+ if l_v2 == 0 {
+ return l_v1;
+ }
+ if l_v1 > l_v2 {
+ return distance(s2, s1);
+ }
+
+ let mut col: Vec<usize> = (0..=l_v1).collect();
+
+ for i in 1..=l_v2 {
+ let mut last_diag = col[0];
+ col[0] += 1;
+ for j in 1..=l_v1 {
+ let last_diag_temp = col[j];
+ if v1[j-1] == v2[i-1] {
+ col[j] = last_diag;
+ } else {
+ col[j] = min(last_diag, min(col[j-1], col[j])) + 1;
+ }
+ last_diag = last_diag_temp;
+ }
+ }
+
+ col[l_v1]
+}
+
+
+#[cfg(test)]
+mod tests {
+ use crate::levenshtein::*;
+ #[test]
+ fn test1() {
+ assert_eq!(distance("kitten", "sitting"), 3);
+ }
+
+ #[test]
+ fn test_diff_len() {
+ assert_eq!(distance("kit", "kitten"), 3);
+ }
+
+ #[test]
+ fn test_equal() {
+ assert_eq!(distance("test", "test"), 0);
+ assert_eq!(distance("", ""), 0);
+ assert_eq!(distance("long string with space", "long string with space"), 0);
+ assert_eq!(distance("unicode 😀", "unicode 😀"), 0);
+ }
+
+ #[test]
+ fn test_one_empty() {
+ assert_eq!(distance("test", ""), 4);
+ assert_eq!(distance("", "test"), 4);
+ assert_eq!(distance("", ""), 0);
+ assert_eq!(distance("long string", ""), 11);
+ assert_eq!(distance("😀", ""), 1);
+ }
+}