Replace unmaintained unidecode with deunicode

Cargo.toml

@@ -16,13 +16,13 @@ crossbeam-utils = "0.8"
 unicode-segmentation = "1.9"
 unicode-normalization = "0.1"
 unicode-case-mapping = "0.4"
-unidecode = "0.3"
 libc = { version = "0.2", optional = true }
 phf = "0.11"
 serde = { version = "1.0", features = ["derive"], optional = true }
 serde_json = { version = "1.0", optional = true }
 smallvec = { features = ["union"], version = "1.9" }
 compact_str = { version = "0.7.1", features = ["serde"] }
+deunicode = "1.4.3"
 
 [dev-dependencies]
 alloc_counter = "0.0"

src/comparison.rs

@@ -43,7 +43,7 @@ impl Name {
     /// names and/or suffixes are present in both names, they must match as well.
     ///
     /// Transliterates everything to ASCII before comparison using the naive
-    /// algorithm of [unidecode](https://github.com/chowdhurya/rust-unidecode/)
+    /// algorithm of [deunicode](https://github.com/kornelski/deunicode/blob/main/README.md)
     /// (which ignores context), and ignores case, accents and combining marks.
     ///
     /// In the case of given and middle names, allows one name to be a prefix of

src/lib.rs

@@ -6,10 +6,10 @@
 #![cfg_attr(feature = "bench", feature(test))]
 
 extern crate crossbeam_utils;
+extern crate deunicode;
 extern crate smallvec;
 extern crate unicode_normalization;
 extern crate unicode_segmentation;
-extern crate unidecode;
 
 #[cfg(test)]
 #[cfg(feature = "bench")]

src/transliterate.rs

@@ -1,14 +1,12 @@
+use deunicode::deunicode_char;
 use std::str::Chars;
-use unidecode::unidecode_char;
 
 #[inline]
-fn transliterate(c: char) -> Chars<'static> {
-    let s = unidecode_char(c);
-    if s.is_empty() {};
+fn transliterate(c: char) -> Option<Chars<'static>> {
     // We should maybe use unicode case folding here as an initial pass,
     // but without a concrete motivating case (yet) it doesn't seem worth
     // the cost.
-    unidecode_char(c).chars()
+    deunicode_char(c).map(|s| s.chars())
 }
 
 #[inline]
@@ -41,14 +39,15 @@ fn ascii_to_upper_if_alpha(c: char) -> Option<char> {
 pub fn to_ascii_initial(c: char) -> Option<char> {
     match c {
         'A'..='Z' => Some(c),
-        _ => transliterate(c).find_map(ascii_to_upper_if_alpha),
+        _ => transliterate(c)?.find_map(ascii_to_upper_if_alpha),
     }
 }
 
 pub fn to_ascii_casefolded(text: &str) -> Option<impl Iterator<Item = char> + '_> {
     let mut result = text
         .chars()
-        .flat_map(transliterate)
+        .filter_map(transliterate)
+        .flatten()
         .filter_map(ascii_to_lower_if_alpha)
         .peekable();
 
@@ -63,7 +62,8 @@ pub fn to_ascii_casefolded(text: &str) -> Option<impl Iterator<Item = char> + '_
 pub fn to_ascii_casefolded_reversed(text: &str) -> Option<impl Iterator<Item = char> + '_> {
     let mut result = text
         .chars()
-        .flat_map(transliterate)
+        .filter_map(transliterate)
+        .flatten()
         .rev()
         .filter_map(ascii_to_lower_if_alpha)
         .peekable();
@@ -79,7 +79,8 @@ pub fn to_ascii_casefolded_reversed(text: &str) -> Option<impl Iterator<Item = c
 pub fn to_ascii_titlecase(s: &str) -> Option<String> {
     let mut result = s
         .chars()
-        .flat_map(transliterate)
+        .filter_map(transliterate)
+        .flatten()
         .filter_map(ascii_to_lower_if_alpha);
 
     result.next().map(|initial| {