pull try out of Add

deferring a recovery handler is normal in Go but opaque. Pulling out a helper for this (`try`) makes it more obvious that this is just another "if this operation fails, return error" case.

koboldsim/stats.go

@@ -220,7 +220,7 @@ var ErrFieldSetPanic = fmt.Errorf("%w: panic when setting", ErrBadFieldLabel)
 // Use a FieldLabel to add an amount to the matching field. If no such
 // field can be found, the field is not exported, or the field is not
 // of type float64, this returns an error ad does not change any values.
-func (k *KoboldMine) Add(which FieldLabel, amount float64) (finalErr error) {
+func (k *KoboldMine) Add(which FieldLabel, amount float64) error {
 	kv := reflect.ValueOf(k).Elem()
 	f := kv.FieldByName(string(which))
 	if !f.IsValid() {
@@ -230,15 +230,8 @@ func (k *KoboldMine) Add(which FieldLabel, amount float64) (finalErr error) {
 		return fmt.Errorf("cannot add %f to field %q: %w", amount, which, ErrFieldNotFloat)
 	}
 
-	defer func() {
-		if r := recover(); r != nil {
-			if e, ok := r.(error); ok {
-				finalErr = fmt.Errorf("could not add %f to field %q: %w: %w", amount, which, ErrFieldSetPanic, e)
-			} else {
-				finalErr = fmt.Errorf("could not add %f to field %q: %w: %v", amount, which, ErrFieldSetPanic, r)
-			}
-		}
-	}()
-	f.SetFloat(f.Float() + amount)
+	if err := try(func() { f.SetFloat(f.Float() + amount) }); err != nil {
+		return fmt.Errorf("could not add %f to field %q: %w", amount, which, err)
+	}
 	return nil
 }