rsoundex

extensions/fuzzy/src/lib.rs

@@ -5,10 +5,11 @@ mod caver;
 mod common;
 mod editdist;
 mod phonetic;
+mod rsoundex;
 mod soundex;
 
 register_extension! {
-    scalars: {levenshtein, damerau_levenshtein, edit_distance, hamming, jaronwin, osadist, fuzzy_soundex, fuzzy_phonetic, fuzzy_caver},
+    scalars: {levenshtein, damerau_levenshtein, edit_distance, hamming, jaronwin, osadist, fuzzy_soundex, fuzzy_phonetic, fuzzy_caver, fuzzy_rsoundex},
 }
 
 /// Calculates and returns the Levenshtein distance of two non NULL strings.
@@ -419,6 +420,16 @@ pub fn fuzzy_caver(args: &[Value]) {
     }
 }
 
+#[scalar(name = "fuzzy_rsoundex")]
+pub fn fuzzy_rsoundex(args: &[Value]) {
+    let arg1 = args[0].to_text();
+    if let Some(txt) = rsoundex::rsoundex(arg1) {
+        Value::from_text(txt)
+    } else {
+        Value::null()
+    }
+}
+
 //tests adapted from sqlean fuzzy
 #[cfg(test)]
 mod tests {
@@ -599,4 +610,22 @@ mod tests {
             );
         }
     }
+    #[test]
+    fn test_rsoundex() {
+        let cases = vec![
+            (None, None),
+            (Some(""), Some("".to_string())),
+            (Some("phonetics"), Some("P1080603".to_string())),
+            (Some("is"), Some("I03".to_string())),
+            (Some("awesome"), Some("A03080".to_string())),
+        ];
+
+        for (input, expected) in cases {
+            let result = rsoundex::rsoundex(input);
+            assert_eq!(
+                result, expected,
+                "fuzzy_rsoundex({input:?}) failed: expected {expected:?}, got {result:?}"
+            );
+        }
+    }
 }

extensions/fuzzy/src/rsoundex.rs

@@ -0,0 +1,49 @@
+/// Computes and returns the soundex representation of a given non NULL string.
+/// More information about the algorithm can be found here:
+///     http://ntz-develop.blogspot.com/2011/03/phonetic-algorithms.html
+pub fn rsoundex(input: Option<&str>) -> Option<String> {
+    if let Some(s) = input {
+        if s.is_empty() {
+            return Some("".to_string());
+        }
+
+        let str_bytes = s.as_bytes();
+        let str_len = str_bytes.len();
+
+        let mut code = String::with_capacity(str_len + 1);
+        code.push(str_bytes[0].to_ascii_uppercase() as char);
+
+        let mut buf: Vec<char> = Vec::with_capacity(str_len);
+        for &b in str_bytes {
+            buf.push(refined_soundex_encode(b as char));
+        }
+
+        let mut prev: Option<char> = None;
+        for c in buf {
+            if Some(c) != prev {
+                code.push(c);
+                prev = Some(c);
+            }
+        }
+
+        Some(code)
+    } else {
+        None
+    }
+}
+
+//helper
+fn refined_soundex_encode(c: char) -> char {
+    match c.to_ascii_lowercase() {
+        'b' | 'p' => '1',
+        'f' | 'v' => '2',
+        'c' | 'k' | 's' => '3',
+        'g' | 'j' => '4',
+        'q' | 'x' | 'z' => '5',
+        'd' | 't' => '6',
+        'l' => '7',
+        'm' | 'n' => '8',
+        'r' => '9',
+        _ => '0',
+    }
+}

testing/cli_tests/extensions.py

@@ -590,6 +590,9 @@ def validate_fuzzy_phonetic(a):
 def validate_fuzzy_caver(a):
     return a == "AWSM111111"
 
+def validate_fuzzy_rsoundex(a):
+    return a == "A03080"
+
 def test_fuzzy():
     limbo = TestTursoShell()
     ext_path = "./target/debug/liblimbo_fuzzy"
@@ -644,6 +647,11 @@ def test_fuzzy():
         validate_fuzzy_caver,
         "fuzzy caver function works",
     )
+    limbo.run_test_fn(
+        "SELECT fuzzy_rsoundex('awesome');",
+        validate_fuzzy_rsoundex,
+        "fuzzy rsoundex function works",
+    )
 
 def test_vfs():
     limbo = TestTursoShell()