Use a helper method for adding notification listeners.

wutil-rs/src/notification.rs

@@ -1,11 +1,28 @@
 use std::{
     collections::{hash_map::Entry, HashMap},
     ffi::{c_void, CStr},
-    hash,
+    hash::{self, Hash},
     ptr::{self, NonNull},
     sync::{Mutex, OnceLock},
 };
 
+// Helper function for adding the entry `(key, (observer, action))` to `map`.
+fn register<K: Eq + Hash>(
+    map: &mut HashMap<K, Vec<(Option<Sendable>, Action)>>,
+    key: K,
+    observer: Option<Sendable>,
+    action: Action,
+) {
+    match map.entry(key) {
+        Entry::Occupied(mut o) => {
+            o.get_mut().push((observer, action));
+        }
+        Entry::Vacant(v) => {
+            v.insert(vec![(observer, action)]);
+        }
+    }
+}
+
 /// Lightweight message from object to another. When a notification is sent,
 /// registered [`Action`]s are called.
 ///
@@ -119,14 +136,7 @@ impl NotificationCenter {
         observer: Option<Sendable>,
         action: Action,
     ) {
-        match self.exact.entry((name, source)) {
-            Entry::Occupied(mut o) => {
-                o.get_mut().push((observer, action));
-            }
-            Entry::Vacant(v) => {
-                v.insert(vec![(observer, action)]);
-            }
-        }
+        register(&mut self.exact, (name, source), observer, action);
     }
 
     /// Registers `action` to be invoked on `observer` when notifications are
@@ -137,14 +147,7 @@ impl NotificationCenter {
         observer: Option<Sendable>,
         action: Action,
     ) {
-        match self.by_source.entry(source) {
-            Entry::Occupied(mut o) => {
-                o.get_mut().push((observer, action));
-            }
-            Entry::Vacant(v) => {
-                v.insert(vec![(observer, action)]);
-            }
-        }
+        register(&mut self.by_source, source, observer, action);
     }
 
     /// Registers `action` to be invoked on `observer` for all notifications
@@ -155,14 +158,7 @@ impl NotificationCenter {
         observer: Option<Sendable>,
         action: Action,
     ) {
-        match self.by_name.entry(name) {
-            Entry::Occupied(mut o) => {
-                o.get_mut().push((observer, action));
-            }
-            Entry::Vacant(v) => {
-                v.insert(vec![(observer, action)]);
-            }
-        }
+        register(&mut self.by_name, name, observer, action);
     }
 
     /// Registers `action` to be invoked on `observer` for all notifications,