src/de/steamwar/command/AbstractTypeMapper.java

@@ -1,6 +1,6 @@
 package de.steamwar.command;
 
-import java.util.List;
+import java.util.Collection;
 
 public interface AbstractTypeMapper<K, T> {
     /**
@@ -8,5 +8,5 @@ public interface AbstractTypeMapper<K, T> {
      */
     T map(K sender, String[] previousArguments, String s);
 
-    List<String> tabCompletes(K sender, String[] previousArguments, String s);
+    Collection<String> tabCompletes(K sender, String[] previousArguments, String s);
 }

src/de/steamwar/command/CommandPart.java

@@ -5,6 +5,7 @@ import lombok.Setter;
 
 import java.lang.reflect.Array;
 import java.util.Arrays;
+import java.util.Collection;
 import java.util.List;
 
 class CommandPart<T> {
@@ -138,7 +139,7 @@ class CommandPart<T> {
                     return;
                 }
             }
-            List<String> strings = typeMapper.tabCompletes(sender, Arrays.copyOf(args, args.length - 1), args[args.length - 1]);
+            Collection<String> strings = typeMapper.tabCompletes(sender, Arrays.copyOf(args, args.length - 1), args[args.length - 1]);
             if (strings != null) {
                 current.addAll(strings);
             }
@@ -157,7 +158,7 @@ class CommandPart<T> {
             return;
         }
 
-        List<String> strings = typeMapper.tabCompletes(sender, Arrays.copyOf(args, startIndex), args[startIndex]);
+        Collection<String> strings = typeMapper.tabCompletes(sender, Arrays.copyOf(args, startIndex), args[startIndex]);
         if (strings != null) {
             current.addAll(strings);
         }

src/de/steamwar/command/SWCommandUtils.java

@@ -9,7 +9,6 @@ import java.lang.reflect.Parameter;
 import java.util.*;
 import java.util.function.BiFunction;
 import java.util.function.Function;
-import java.util.stream.Collectors;
 
 @UtilityClass
 public class SWCommandUtils {
@@ -198,20 +197,19 @@ public class SWCommandUtils {
     }
 
     public static AbstractTypeMapper<?, Enum<?>> createEnumMapper(Class<Enum<?>> enumClass) {
-        Enum<?>[] enums = enumClass.getEnumConstants();
-        List<String> strings = Arrays.stream(enums).map(Enum::name).map(String::toLowerCase).collect(Collectors.toList());
+        Map<String, Enum<?>> enumMap = new HashMap<>();
+        for (Enum<?> e : enumClass.getEnumConstants()) {
+            enumMap.put(e.name(), e);
+        }
         return new AbstractTypeMapper<Object, Enum<?>>() {
             @Override
             public Enum<?> map(Object commandSender, String[] previousArguments, String s) {
-                for (Enum<?> e : enums) {
-                    if (e.name().equalsIgnoreCase(s)) return e;
-                }
-                return null;
+                return enumMap.get(s);
             }
 
             @Override
-            public List<String> tabCompletes(Object commandSender, String[] previousArguments, String s) {
-                return strings;
+            public Collection<String> tabCompletes(Object commandSender, String[] previousArguments, String s) {
+                return enumMap.keySet();
             }
         };
     }