Remove multithreading for sorting

The relevant processes are so fast, mutexes and mutex locks are so
expensive, and iterators so efficient, that it's actually faster to run
single-threaded across all the data than to spin up a bunch of threads
and have them basically spinlock waiting for the global mutex involved
either directly or in a channel.

ivy_files(kubernetes)   time:   [10.209 ms 10.245 ms 10.286 ms]
                        change: [-36.781% -36.178% -35.601%] (p = 0.00 < 0.05)
                        Performance has improved.

ivy_match(file.lua)     time:   [1.1626 µs 1.1668 µs 1.1709 µs]
                        change: [+0.2131% +1.5409% +2.9109%] (p = 0.02 < 0.05)
                        Change within noise threshold.

examples/filename_search.rs

@@ -1,5 +1,7 @@
 use ivyrs::inner_files;
 
 pub fn main() {
-    inner_files("file.go".to_owned(), "/tmp/ivy-trees/kubernetes".to_owned());
+    let res = inner_files("file.go".to_owned(), "/tmp/ivy-trees/kubernetes".to_owned());
+
+    println!("{}", res);
 }

rust/lib.rs

@@ -52,7 +52,7 @@ pub extern "C" fn ivy_match(c_pattern: *const c_char, c_text: *const c_char) ->
 pub fn inner_match(pattern: String, text: String) -> i32 {
     let m = matcher::Matcher::new(pattern);
 
-    m.score(text) as i32
+    m.score(text.as_str()) as i32
 }
 
 #[no_mangle]

rust/matcher.rs

@@ -15,9 +15,9 @@ impl Matcher {
         }
     }
 
-    pub fn score(&self, text: String) -> i64 {
+    pub fn score(&self, text: &str) -> i64 {
         self.matcher
-            .fuzzy_indices(&text, &self.pattern)
+            .fuzzy_indices(text, &self.pattern)
             .map(|(score, _indices)| score)
             .unwrap_or_default()
     }

rust/sorter.rs

@@ -24,36 +24,16 @@ impl Options {
 }
 
 pub fn sort_strings(options: Options, strings: Vec<String>) -> Vec<Match> {
-    let mut matches = Vec::new();
-    let matcher = Arc::new(matcher::Matcher::new(options.pattern));
+    let matcher = matcher::Matcher::new(options.pattern);
 
-    let pool = thread_pool::ThreadPool::new(std::thread::available_parallelism().unwrap().get());
-
-    let (tx, rx) = mpsc::channel::<Match>();
-
-    for string in strings {
-        let thread_matcher = Arc::clone(&matcher);
-        let thread_transmitter = tx.clone();
-        pool.execute(move || {
-            let score = thread_matcher.score(string.to_string());
-            if score > 25 {
-                thread_transmitter
-                    .send(Match {
-                        score,
-                        content: string,
-                    })
-                    .expect("Failed to push data to channel");
-            }
+    let mut matches = strings
+        .into_iter()
+        .map(|candidate| Match {
+            score: matcher.score(candidate.as_str()),
+            content: candidate,
         })
-    }
-
-    drop(pool);
-    drop(tx);
-
-    while let Ok(result) = rx.recv() {
-        matches.push(result)
-    }
-
+        .filter(|m| m.score > 25)
+        .collect::<Vec<Match>>();
     matches.sort_by(|a, b| a.score.cmp(&b.score));
     matches
 }