remove unneeded mutability modifier

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "prongs"
-version = "0.0.3"
+version = "0.0.4"
 authors = ["Ales Katona <almindor@gmail.com>"]
 edition = "2018"
 readme = "README.md"

src/backend_gilrs.rs

@@ -33,7 +33,7 @@ where TUserAction: Clone + Serialize,
         self.schema.clear_assignments();
     }
 
-    pub fn process_event(&mut self, event: &Event) -> Option<ProcessingResult<TUserAction>> {
+    pub fn process_event(&self, event: &Event) -> Option<ProcessingResult<TUserAction>> {
         self.schema.process_event(event)
     }
 

src/backend_piston.rs

@@ -41,7 +41,7 @@ where TUserAction: Clone + Serialize,
 
     /// Main event processing hook. Will result in ProcessingResult for user's action if
     /// a mapping is withing the schema for the given event.
-    pub fn process_event(&mut self, event: &Event) -> Option<ProcessingResult<TUserAction>> {
+    pub fn process_event(&self, event: &Event) -> Option<ProcessingResult<TUserAction>> {
         self.schema.process_event(event)
     }
 

src/lib.rs

@@ -132,7 +132,7 @@ where TEventType: ToEventType<TControllerID>,
 
     /// Main processing loop. Takes input event and returns an option with processing result
     /// If the mapping was found result will be set, otherwise None
-    fn process_event(&mut self, event: &TEventType) -> Option<ProcessingResult<TUserAction>> {
+    fn process_event(&self, event: &TEventType) -> Option<ProcessingResult<TUserAction>> {
         if let Some(event_type) = event.to_raw() {
             if let Some(action) = self.keymap.get(&event_type) {
                 if self.controller_id.is_some() && self.controller_id != event.controller_id() {