use usize not i32 here

src/function.rs

@@ -97,7 +97,7 @@ impl Default for FunctionEntry {
 
 impl FunctionEntry {
 	/// Create autocomplete ui and handle user input
-	pub fn auto_complete(&mut self, ui: &mut egui::Ui, i: i32) {
+	pub fn auto_complete(&mut self, ui: &mut egui::Ui, i: usize) {
 		self.autocomplete.update_string(&self.raw_func_str);
 		self.autocomplete.ui(ui, i);
 

src/math_app.rs

@@ -474,7 +474,7 @@ impl MathApp {
 						);
 
 						// Contains the function string in a text box that the user can edit
-						function.auto_complete(ui, i as i32)
+						function.auto_complete(ui, i)
 					});
 					function.settings(ctx);
 				}

src/widgets.rs

@@ -80,7 +80,7 @@ impl<'a> AutoComplete<'a> {
 		self.update_string(&new_string);
 	}
 
-	pub fn ui(&mut self, ui: &mut egui::Ui, func_i: i32) {
+	pub fn ui(&mut self, ui: &mut egui::Ui, func_i: usize) {
 		let mut movement: Movement = Movement::default();
 
 		let mut new_string = self.string.clone();