categories not an enum, so its easier to extend. Validators can modify value.

src/main/java/carpet/settings/Validator.java

@@ -11,40 +11,42 @@ public abstract class Validator<T> {
      * Validate the new value of a rule
      * @return true if valid, false if new rule invalid.
      */
-    abstract boolean validate(ServerCommandSource source, ParsedRule<T> currentRule, T newValue, String string);
+    abstract T validate(ServerCommandSource source, ParsedRule<T> currentRule, T newValue, String string);
 
 
     public static class POSITIVE_NUMBER<T extends Number> extends Validator<T> {
         @Override
-        public boolean validate(ServerCommandSource source, ParsedRule<T> currentRule, T newValue, String string) {
-            return newValue.doubleValue() > 0;
+        public T validate(ServerCommandSource source, ParsedRule<T> currentRule, T newValue, String string) {
+            return newValue.doubleValue() > 0 ? newValue : null;
         }
     }
 
+
+
     public static class _COMMAND<T> extends Validator<T> {
         @Override
-        public boolean validate(ServerCommandSource source, ParsedRule<T> currentRule, T newValue, String string) {
+        public T validate(ServerCommandSource source, ParsedRule<T> currentRule, T newValue, String string) {
             if (CarpetServer.settingsManager != null)
                 CarpetServer.settingsManager.notifyPlayersCommandsChanged();
-            return true;
+            return newValue;
         }
     }
 
     public static class WIP<T> extends Validator<T> {
         @Override
-        public boolean validate(ServerCommandSource source, ParsedRule<T> currentRule, T newValue, String string) {
+        public T validate(ServerCommandSource source, ParsedRule<T> currentRule, T newValue, String string) {
             if (source != null)
                 try
                 {
                     Messenger.m(source, "r Work in progress - limited or no functionality available for "+currentRule.name);
                 }
                 catch (NullPointerException ignored) { }
-            return true;
+            return newValue;
         }
     }
     public static class _STRICT<T> extends Validator<T> {
         @Override
-        public boolean validate(ServerCommandSource source, ParsedRule<T> currentRule, T newValue, String string) {
+        public T validate(ServerCommandSource source, ParsedRule<T> currentRule, T newValue, String string) {
             if (!currentRule.options.contains(string.toLowerCase(Locale.ROOT)))
             {
                 if (source != null)
@@ -55,9 +57,9 @@ public abstract class Validator<T> {
                     catch (NullPointerException ignored)
                     {
                     }
-                return false;
+                return null;
             }
-            return true;
+            return newValue;
         }
     }
 }