Some preparations for a cmd arg rework

These are some preparations so everybody can be ready for a rework of how command arguments is handled.

src/com/massivecraft/massivecore/PredictateStartsWithIgnoreCase.java

@@ -0,0 +1,33 @@
+package com.massivecraft.massivecore;
+
+public class PredictateStartsWithIgnoreCase implements Predictate<String>
+{
+	// -------------------------------------------- //
+	// FIELDS
+	// -------------------------------------------- //
+	
+	private final String prefix;
+	public String getPrefix() { return this.prefix; };
+	
+	// -------------------------------------------- //
+	// CONSTRUCT
+	// -------------------------------------------- //
+	
+	public static PredictateStartsWithIgnoreCase get(String prefix) { return new PredictateStartsWithIgnoreCase(prefix); }
+	public PredictateStartsWithIgnoreCase(String prefix)
+	{
+		this.prefix = prefix.toLowerCase();
+	}
+
+	// -------------------------------------------- //
+	// OVERRIDE
+	// -------------------------------------------- //
+
+	@Override
+	public boolean apply(String str)
+	{
+		if (str == null) return false;
+		return str.toLowerCase().startsWith(this.getPrefix());
+	}
+	
+}

src/com/massivecraft/massivecore/SoundEffect.java

@@ -7,6 +7,7 @@ import org.bukkit.Location;
 import org.bukkit.Sound;
 import org.bukkit.entity.Player;
 
+import com.massivecraft.massivecore.cmd.arg.ARFloat;
 import com.massivecraft.massivecore.cmd.arg.ARSound;
 
 public final class SoundEffect implements Cloneable, Serializable
@@ -66,19 +67,18 @@ public final class SoundEffect implements Cloneable, Serializable
 		soundString = soundString.trim();
 		
 		String[] parts = soundString.split("[^a-zA-Z0-9_.]+");
-		Sound sound = ARSound.getSoundFromString(parts[0]);
-		if (sound == null) throw new IllegalArgumentException("Unknown sound \"" + parts[0] + "\"");
+		Sound sound = ARSound.get().read(parts[0]);
 		
 		float volume = 1.0f;
 		if (parts.length >= 2)
 		{
-			volume = Float.parseFloat(parts[1]);
+			volume = ARFloat.get().read(parts[1]);
 		}
 		
 		float pitch = 1.0f;
 		if (parts.length >= 3)
 		{
-			pitch = Float.parseFloat(parts[2]);
+			pitch = ARFloat.get().read(parts[2]);
 		}
 		
 		return SoundEffect.valueOf(sound, volume, pitch);

src/com/massivecraft/massivecore/cmd/MassiveCommand.java

@@ -18,7 +18,7 @@ import org.bukkit.plugin.Plugin;
 import com.massivecraft.massivecore.Lang;
 import com.massivecraft.massivecore.MassiveCore;
 import com.massivecraft.massivecore.MassiveException;
-import com.massivecraft.massivecore.cmd.arg.ArgReader;
+import com.massivecraft.massivecore.cmd.arg.AR;
 import com.massivecraft.massivecore.cmd.req.Req;
 import com.massivecraft.massivecore.cmd.req.ReqHasPerm;
 import com.massivecraft.massivecore.collections.MassiveList;
@@ -523,9 +523,10 @@ public class MassiveCommand
 	
 	public int getMaxLevenshteinDistanceForArg(String arg)
 	{
+		if (arg == null) return 0;
 		if (arg.length() <= 1) return 0; // When dealing with 1 character aliases, there is way too many options. So we don't suggest.
-		if (arg.length() <= 3) return 1; // When dealing with low length aliases, there too many options. So we won't suggest much
-		if (arg.length() < 8) return 2; // 2 is default.
+		if (arg.length() <= 4) return 1; // When dealing with low length aliases, there too many options. So we won't suggest much
+		if (arg.length() <= 7) return 2; // 2 is default.
 		
 		return 3; // If it were 8 characters or more, we end up here. Because many characters allow for more typos.
 	}
@@ -693,13 +694,13 @@ public class MassiveCommand
 		return this.getArgs().get(idx);
 	}
 	
-	public <T> T arg(int idx, ArgReader<T> argReader) throws MassiveException
+	public <T> T arg(int idx, AR<T> argReader) throws MassiveException
 	{
 		String str = this.arg(idx);
 		return this.arg(str, argReader);
 	}
 	
-	public <T> T arg(int idx, ArgReader<T> argReader, T defaultNotSet) throws MassiveException
+	public <T> T arg(int idx, AR<T> argReader, T defaultNotSet) throws MassiveException
 	{
 		String str = this.arg(idx);
 		return this.arg(str, argReader, defaultNotSet);
@@ -716,13 +717,13 @@ public class MassiveCommand
 		return Txt.implode(this.getArgs().subList(from, to), " ");
 	}
 	
-	public <T> T argConcatFrom(int idx, ArgReader<T> argReader) throws MassiveException
+	public <T> T argConcatFrom(int idx, AR<T> argReader) throws MassiveException
 	{
 		String str = this.argConcatFrom(idx);
 		return this.arg(str, argReader);
 	}
 	
-	public <T> T argConcatFrom(int idx, ArgReader<T> argReader, T defaultNotSet) throws MassiveException
+	public <T> T argConcatFrom(int idx, AR<T> argReader, T defaultNotSet) throws MassiveException
 	{
 		String str = this.argConcatFrom(idx);
 		return this.arg(str, argReader, defaultNotSet);
@@ -730,18 +731,17 @@ public class MassiveCommand
 	
 	// Core & Other
 	
-	public <T> T arg(ArgReader<T> argReader) throws MassiveException
+	public <T> T arg(AR<T> argReader) throws MassiveException
 	{
 		return this.arg(null, argReader);
 	}
 	
-	public <T> T arg(String str, ArgReader<T> argReader) throws MassiveException
+	public <T> T arg(String str, AR<T> argReader) throws MassiveException
 	{
-		T result = argReader.read(str, this.sender);
-		return result;
+		return argReader.read(str, this.sender);
 	}
 	
-	public <T> T arg(String str, ArgReader<T> argReader, T defaultNotSet) throws MassiveException
+	public <T> T arg(String str, AR<T> argReader, T defaultNotSet) throws MassiveException
 	{
 		if (str == null) return defaultNotSet;
 		return this.arg(str, argReader);

src/com/massivecraft/massivecore/cmd/arg/AMain.java

@@ -0,0 +1,28 @@
+package com.massivecraft.massivecore.cmd.arg;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class AMain
+{
+	// This class is temporarily here for testing.
+	public static void main(String[] args)
+	{
+		try
+		{
+			System.out.println("start");
+			List<String> input = new ArrayList<String>();
+		
+			input.add("1");
+		
+			for(String str : ARAbstract.prepareForSpaces(input))
+				System.out.println("\"" + str + "\"");
+			System.out.println("end");
+		}
+		catch(Throwable t)
+		{
+			t.printStackTrace();
+		}
+	}
+
+}

src/com/massivecraft/massivecore/cmd/arg/AR.java

@@ -0,0 +1,34 @@
+package com.massivecraft.massivecore.cmd.arg;
+
+import java.util.Collection;
+import java.util.List;
+
+import org.bukkit.command.CommandSender;
+
+import com.massivecraft.massivecore.MassiveException;
+
+public interface AR<T>
+{	
+	// Human friendly name
+	public String getTypeName();
+	
+	// Read
+	public T read(String arg, CommandSender sender) throws MassiveException;
+	public T read(CommandSender sender) throws MassiveException;
+	public T read(String arg) throws MassiveException;
+	public T read() throws MassiveException;
+
+	// Valid (used for arbitary argument order)
+	public boolean isValid(String arg, CommandSender sender);
+	
+	// Tab list
+	// The sender is the one that tried to tab complete.
+	// The arg is beginning the word they are trying to tab complete.
+	public Collection<String> getTabList(CommandSender sender, String arg);
+	public List<String> getTabListFiltered(CommandSender sender, String arg);
+	
+	// Sometimes we put a space after a tab completion.
+	// That would however not make sense with all ArgReaders.
+	// Default is true;
+	public boolean allowSpaceAfterTab();
+}

src/com/massivecraft/massivecore/cmd/arg/ARAbstract.java

@@ -0,0 +1,230 @@
+package com.massivecraft.massivecore.cmd.arg;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.List;
+
+import org.bukkit.command.CommandSender;
+
+import com.google.common.collect.Lists;
+import com.massivecraft.massivecore.MassiveException;
+import com.massivecraft.massivecore.util.Txt;
+
+public abstract class ARAbstract<T> implements AR<T>
+{
+	// -------------------------------------------- //
+	// OVERRIDE: READ
+	// -------------------------------------------- //
+	
+	@Override
+	public T read(CommandSender sender) throws MassiveException
+	{
+		return this.read(null, sender);
+	}
+
+	@Override
+	public T read(String arg) throws MassiveException
+	{
+		return this.read(arg, null);
+	}
+
+	@Override
+	public T read() throws MassiveException
+	{
+		return this.read(null, null);
+	}
+	
+	// -------------------------------------------- //
+	// OVERRIDE: VALID
+	// -------------------------------------------- //
+	
+	@Override
+	public boolean isValid(String arg, CommandSender sender)
+	{
+		try
+		{
+			this.read(arg, sender);
+			return true;
+		}
+		catch (MassiveException ex)
+		{
+			return false;
+		}
+	}
+	
+	// -------------------------------------------- //
+	// OVERRIDE: NAME
+	// -------------------------------------------- //
+	
+	@Override
+	public String getTypeName()
+	{
+		int prefixLength = "AR".length();
+		String name = this.getClass().getSimpleName();
+		
+		// We don't want the "AR" part
+		name = name.substring(prefixLength);
+		
+		// We split at uppercase letters, because most class names are camel-case.
+		final String[] words = name.split("(?=[A-Z])");
+		return Txt.implode(words, " ").toLowerCase();
+	}
+	
+	// -------------------------------------------- //
+	// OVERRIDE: TAB
+	// -------------------------------------------- //
+
+	@Override
+	public boolean allowSpaceAfterTab()
+	{
+		return true;
+	}
+	
+	@Override
+	public List<String> getTabListFiltered(CommandSender sender, String arg)
+	{
+		// Filter them to start with what the user typed in.
+		Collection<String> raw = this.getTabList(sender, arg);
+		if (raw == null) return Collections.emptyList();
+		List<String> ret = Txt.getStartsWithIgnoreCase(raw, arg);
+		
+		// Here we do a lot of things related to spaces.
+		// Because spaces and tab completion desn't go well together.
+		// In the future we might be able to do something better,
+		// but MineCraft has its limitations.
+		ret = prepareForSpaces(ret);
+		
+		return ret;
+	}
+	
+	// -------------------------------------------- //
+	// PRIVATE: TAB COMPLETE CALCULATIONS
+	// -------------------------------------------- //
+	
+	// Should be private. But isn't currently for testing purposes.
+	static List<String> prepareForSpaces(List<String> suggestions)
+	{
+		List<List<String>> suggestionParts = getParts(suggestions);
+		
+		// This will get the common prefix for all passed in suggestions.
+		// This will allow us to tab complete somethings with spaces
+		// if we know they all start with the same value,
+		// so we don't have to replace all of it.
+		List<String> prefix = getPrefix(suggestionParts);
+		// This is all the suggetions without the common prefix.
+		List<String> ret = withoutPreAndSuffix(suggestionParts, prefix);
+		// If it isn't empty and there is a prefix...
+		if ( ! ret.isEmpty() && ! prefix.isEmpty())
+		{
+			// ...then we want the first one to have the prefix.
+			// That prefix is not removed automatically,
+			// due to how tab completion works.
+			final String current = ret.get(0);
+			final String prefixStr = Txt.implode(prefix, " ");
+			String result = prefixStr;
+			if ( ! current.isEmpty()) result += " " + current;
+			
+			ret.set(0, result);
+		}
+		
+		return ret;
+	}
+	
+	// This things splits up the arguments at spaces.
+	private static List<List<String>> getParts(List<String> list)
+	{
+		List<List<String>> ret = Lists.newArrayList();
+		
+		for (String str : list)
+		{
+			if (str == null) continue;
+			if (str.isEmpty()) continue;
+			ret.add(Arrays.asList(str.split("\\s+")));
+		}
+		
+		return ret;
+	}
+
+	private static List<String> withoutPreAndSuffix(List<List<String>> suggestionParts, List<String> prefix)
+	{
+		List<String> ret = new ArrayList<String>(suggestionParts.size());
+		boolean includesPrefix = false; // Sometimes a suggestion is equal to the prefix.
+		for (List<String> suggestion : suggestionParts)
+		{
+			if (suggestion.equals(prefix) && !includesPrefix)
+			{
+				ret.add("");
+				includesPrefix = true;
+				continue;
+			}
+			// We remove the prefix because we only want that once.
+			// But we can't keep things after the first part either
+			// because of spaces and stuff.
+			if (suggestion.size() <= prefix.size()) continue;
+			ret.add(suggestion.get(prefix.size()));
+		}
+		
+		return ret;
+	}
+	
+	private static List<String> getPrefix(List<List<String>> suggestionParts)
+	{
+		List<String> prefix = null;
+		
+		for (List<String> suggestion : suggestionParts)
+		{
+			prefix = getOkay(prefix, suggestion);
+		}
+		
+		return prefix;
+	}
+	
+	// This method return a new array only including
+	// the first parts that are equal.
+	private static List<String> getOkay(List<String> original, List<String> compared)
+	{
+		if (original == null) return compared;
+		
+		final int size = Math.min(original.size(), compared.size());
+		List<String> ret = new ArrayList<String>(size);
+		
+		for (int i = 0; i < size; i++)
+		{
+			if (compared.get(i) == null || original.get(i) == null) break;
+			if ( ! compared.get(i).equals(original.get(i))) break;
+			ret.add(original.get(i));
+		}
+
+		return ret;
+	}
+
+	//TODO: Move this code somewhere else.
+	// Currently just kept here.
+	/*
+	private List<String> addSpaceAtEnd(MassiveCommand command, int argNumber, List<String> suggestions)
+	{
+		// This ArgReader must allow space at the end.
+		if ( ! this.allowSpaceAfterTab()) return suggestions;
+		// There must be exactly one suggestion.
+		if (suggestions.size() != 1) return suggestions;
+		
+		// The maximum size of args to pass in.
+		int argsSize = command.getOptionalArgs().size() + command.getRequiredArgs().size();
+		// If it accepts infinite arguments, just make it as high as possible.
+		if (command.getErrorOnToManyArgs()) argsSize = Integer.MAX_VALUE;
+		argsSize--; // It now becomes one smaller, so the size matches index.
+		
+		// So if this was the last arg meaning the user can't to type more in
+		// We will just stop here.
+		if (argNumber >= argsSize) return suggestions;
+		
+		// Get the suggestion.
+		String suggestion = suggestions.get(0);
+		// Add the space at the end.
+		suggestion += " ";
+		return new MassiveCoreSingleValueList<String>(suggestion);
+	}*/
+	
+}

src/com/massivecraft/massivecore/cmd/arg/ARAbstractException.java

@@ -0,0 +1,42 @@
+package com.massivecraft.massivecore.cmd.arg;
+
+import org.bukkit.command.CommandSender;
+
+import com.massivecraft.massivecore.MassiveException;
+import com.massivecraft.massivecore.util.Txt;
+
+public abstract class ARAbstractException<T> extends ARAbstract<T>
+{
+	// -------------------------------------------- //
+	// ABSTRACT
+	// -------------------------------------------- //
+	
+	public abstract T valueOf(String arg, CommandSender sender) throws Exception;
+	
+	// -------------------------------------------- //
+	// OVERRIDE
+	// -------------------------------------------- //
+	
+	@Override
+	public T read(String arg, CommandSender sender) throws MassiveException
+	{
+		try
+		{
+			return this.valueOf(arg, sender);
+		}
+		catch (Exception ex)
+		{
+			throw new MassiveException().addMessage(this.extractErrorMessage(arg, sender, ex));
+		}
+	}
+	
+	// -------------------------------------------- //
+	// MESSAGE (OVERRIDABLE)
+	// -------------------------------------------- //
+
+	public String extractErrorMessage(String arg, CommandSender sender, Exception ex)
+	{
+		return Txt.parse("<b>%s", ex.getMessage());
+	}
+	
+}

src/com/massivecraft/massivecore/cmd/arg/ARAbstractNumber.java

@@ -0,0 +1,27 @@
+package com.massivecraft.massivecore.cmd.arg;
+
+import java.util.Collection;
+import java.util.Collections;
+import java.util.List;
+
+import org.bukkit.command.CommandSender;
+
+public abstract class ARAbstractNumber<T extends Number> extends ARAbstractPrimitive<T>
+{
+	// -------------------------------------------- //
+	// CONSTANTS
+	// -------------------------------------------- //
+	
+	public static final List<String> TAB_LIST = Collections.singletonList("1");
+	
+	// -------------------------------------------- //
+	// OVERRIDE
+	// -------------------------------------------- //
+	
+	@Override
+	public Collection<String> getTabList(CommandSender sender, String arg)
+	{
+		return TAB_LIST;
+	}
+	
+}

src/com/massivecraft/massivecore/cmd/arg/ARAbstractPrimitive.java

@@ -2,36 +2,18 @@ package com.massivecraft.massivecore.cmd.arg;
 
 import org.bukkit.command.CommandSender;
 
-import com.massivecraft.massivecore.MassiveException;
+import com.massivecraft.massivecore.util.Txt;
 
-public abstract class ARAbstractPrimitive<T> extends ArgReaderAbstract<T>
+public abstract class ARAbstractPrimitive<T> extends ARAbstractException<T>
 {	
-	// -------------------------------------------- //
-	// ABSTRACT
-	// -------------------------------------------- //
-	
-	public abstract String typename();
-	public abstract T convert(String arg) throws Exception;
-	
 	// -------------------------------------------- //
 	// OVERRIDE
 	// -------------------------------------------- //
 	
 	@Override
-	public T read(String arg, CommandSender sender) throws MassiveException
+	public String extractErrorMessage(String arg, CommandSender sender, Exception ex)
 	{
-		T result;
-		
-		try
-		{
-			result = this.convert(arg);
-		}
-		catch (Exception e)
-		{
-			throw new MassiveException().addMsg("<b>Invalid %s \"<h>%s<b>\".", this.typename(), arg);
-		}
-		
-		return result;
+		return Txt.parse("<b>\"<h>%s\"<b> is not a %s.", arg, this.getTypeName());
 	}
 
 }

src/com/massivecraft/massivecore/cmd/arg/ARAbstractSelect.java

@@ -2,6 +2,7 @@ package com.massivecraft.massivecore.cmd.arg;
 
 import java.util.ArrayList;
 import java.util.Collection;
+import java.util.Collections;
 import java.util.List;
 
 import org.apache.commons.lang.StringUtils;
@@ -10,7 +11,7 @@ import org.bukkit.command.CommandSender;
 import com.massivecraft.massivecore.MassiveException;
 import com.massivecraft.massivecore.util.Txt;
 
-public abstract class ARAbstractSelect<T> extends ArgReaderAbstract<T>
+public abstract class ARAbstractSelect<T> extends ARAbstract<T>
 {
 	// -------------------------------------------- //
 	// CONSTANT
@@ -22,7 +23,6 @@ public abstract class ARAbstractSelect<T> extends ArgReaderAbstract<T>
 	// ABSTRACT
 	// -------------------------------------------- //
 	
-	public abstract String typename();
 	public abstract T select(String str, CommandSender sender) throws MassiveException;
 	public abstract Collection<String> altNames(CommandSender sender);
 	public boolean canList(CommandSender sender) { return true; }
@@ -39,7 +39,7 @@ public abstract class ARAbstractSelect<T> extends ArgReaderAbstract<T>
 		if (result != null) return result;
 		
 		MassiveException exception = new MassiveException();
-		exception.addMsg("<b>No %s matches \"<h>%s<b>\".", this.typename(), arg);
+		exception.addMsg("<b>No %s matches \"<h>%s<b>\".", this.getTypeName(), arg);
 		
 		if (this.canList(sender))
 		{			
@@ -50,7 +50,7 @@ public abstract class ARAbstractSelect<T> extends ArgReaderAbstract<T>
 			
 			if (names.isEmpty())
 			{
-				exception.addMsg("<i>Note: There is no %s available.", this.typename());
+				exception.addMsg("<i>Note: There is no %s available.", this.getTypeName());
 			}
 			else if ( ! matches.isEmpty() && matches.size() < LIST_COUNT_MAX)
 			{
@@ -77,6 +77,7 @@ public abstract class ARAbstractSelect<T> extends ArgReaderAbstract<T>
 	
 	public List<String> getMatchingAltNames(String arg, CommandSender sender, int maxLevenshteinDistance)
 	{
+		if (arg == null) return Collections.emptyList(); // For some apparent reason this is required.
 		arg = arg.toLowerCase();
 		
 		// Try Levenshtein
@@ -94,8 +95,9 @@ public abstract class ARAbstractSelect<T> extends ArgReaderAbstract<T>
 	
 	public int getMaxLevenshteinDistanceForArg(String arg)
 	{
+		if (arg == null) return 0; // For some apparent reason this is required.
 		if (arg.length() <= 1) return 0; // When dealing with 1 character aliases, there is way too many options.
-		if (arg.length() < 8) return 1; // 1 is default.
+		if (arg.length() <= 7) return 1; // 1 is default.
 		
 		return 2;  // If it were 8 characters or more, we end up here. Because many characters allow for more typos.
 	}

src/com/massivecraft/massivecore/cmd/arg/ARAll.java

@@ -0,0 +1,64 @@
+package com.massivecraft.massivecore.cmd.arg;
+
+import java.util.Collection;
+import java.util.List;
+
+import org.bukkit.command.CommandSender;
+
+import com.massivecraft.massivecore.MassiveException;
+import com.massivecraft.massivecore.collections.MassiveList;
+
+public class ARAll<T> extends ARAbstract<Collection<T>>
+{
+	// -------------------------------------------- //
+	// FIELDS
+	// -------------------------------------------- //
+	
+	private ARAllAble<T> innerArgReader;
+	
+	// -------------------------------------------- //
+	// CONSTRUCT
+	// -------------------------------------------- //
+	
+	public ARAll(ARAllAble<T> inner)
+	{
+		if (inner == null) throw new IllegalArgumentException("innerArgReader musn't be null");
+		this.innerArgReader = inner;
+	}
+	
+	// -------------------------------------------- //
+	// OVERRIDE
+	// -------------------------------------------- //
+
+	@Override
+	public String getTypeName()
+	{
+		return innerArgReader.getTypeName();
+	}
+	
+	@Override
+	public Collection<T> read(String arg, CommandSender sender) throws MassiveException
+	{
+		if ("all".equalsIgnoreCase(arg)) return innerArgReader.getAll();
+		
+		T innerRet = innerArgReader.read(arg, sender);
+		
+		List<T> ret = new MassiveList<T>();
+		ret.add(innerRet);
+		
+		return ret;
+	}
+
+	@Override
+	public boolean isValid(String arg, CommandSender sender)
+	{
+		return "all".equalsIgnoreCase(arg) || innerArgReader.isValid(arg, sender);
+	}
+
+	@Override
+	public Collection<String> getTabList(CommandSender sender, String arg)
+	{
+		return innerArgReader.getTabList(sender, arg);
+	}
+
+}

src/com/massivecraft/massivecore/cmd/arg/ARAllAble.java

@@ -0,0 +1,8 @@
+package com.massivecraft.massivecore.cmd.arg;
+
+import java.util.Collection;
+
+public interface ARAllAble<T> extends AR<T>
+{
+	public Collection<T> getAll();
+}

src/com/massivecraft/massivecore/cmd/arg/ARAspect.java

@@ -21,12 +21,6 @@ public class ARAspect extends ARAbstractSelect<Aspect>
 	// OVERRIDE
 	// -------------------------------------------- //
 
-	@Override
-	public String typename()
-	{
-		return "aspect";
-	}
-
 	@Override
 	public Aspect select(String arg, CommandSender sender)
 	{
@@ -45,4 +39,10 @@ public class ARAspect extends ARAbstractSelect<Aspect>
 		return AspectColl.get().getIds();
 	}
 	
+	@Override
+	public Collection<String> getTabList(CommandSender sender, String arg)
+	{
+		return this.altNames(sender);
+	}
+	
 }

src/com/massivecraft/massivecore/cmd/arg/ARBiome.java

@@ -20,21 +20,14 @@ public class ARBiome extends ARAbstractSelect<Biome>
 	// OVERRIDE
 	// -------------------------------------------- //
 
-	@Override
-	public String typename()
-	{
-		return "biome";
-	}
-
 	@Override
 	public Biome select(String arg, CommandSender sender)
 	{
 		arg = getComparable(arg);
 		
-		String biomestr;
 		for (Biome biome : Biome.values())
 		{
-			biomestr = getComparable(biome.name());
+			String biomestr = getComparable(biome.name());
 			if (biomestr.equals(arg))
 			{
 				return biome;
@@ -64,16 +57,30 @@ public class ARBiome extends ARAbstractSelect<Biome>
 		return ret;
 	}
 
+	@Override
+	public Collection<String> getTabList(CommandSender sender, String arg)
+	{
+		List<String> ret = new ArrayList<String>();
+		
+		for (Biome biome : Biome.values())
+		{
+			ret.add(getComparable(biome.name()));
+		}
+		
+		return ret;
+	}
+	
 	// -------------------------------------------- //
 	// UTIL
 	// -------------------------------------------- //
 	
-	public static String getComparable(String str)
+	public static String getComparable(String string)
 	{
-		str = str.toLowerCase();
-		str = str.replace("_", "");
-		str = str.replace(" ", "");
-		return str;
+		if (string == null) return null;
+		string = string.toLowerCase();
+		string = string.replace("_", "");
+		string = string.replace(" ", "");
+		return string;
 	}
 	
 }

src/com/massivecraft/massivecore/cmd/arg/ARBoolean.java

@@ -1,7 +1,30 @@
 package com.massivecraft.massivecore.cmd.arg;
 
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.List;
+import java.util.Set;
+
+import org.bukkit.command.CommandSender;
+
+import com.massivecraft.massivecore.util.MUtil;
+
 public class ARBoolean extends ARAbstractPrimitive<Boolean>
 {
+	// -------------------------------------------- //
+	// CONSTANTS
+	// -------------------------------------------- //
+	
+	public static final Set<String> TRUE_OPTIONS = MUtil.set(
+			"y", "ye", "yes",
+			"on",
+			"t", "tr", "tru", "true");
+	
+	public static final Set<String> FALSE_OPTIONS = MUtil.set(
+			"n", "no",
+			"of", "off",
+			"f", "fa", "fal", "fals", "false");
+	
 	// -------------------------------------------- //
 	// INSTANCE & CONSTRUCT
 	// -------------------------------------------- //
@@ -14,20 +37,43 @@ public class ARBoolean extends ARAbstractPrimitive<Boolean>
 	// -------------------------------------------- //
 	
 	@Override
-	public String typename()
+	public String getTypeName()
 	{
-		return "boolean";
+		return "toggle";
 	}
 	
 	@Override
-	public Boolean convert(String arg) throws Exception
+	public Boolean valueOf(String arg, CommandSender sender) throws Exception
 	{
 		arg = arg.toLowerCase();
-		if (arg.startsWith("y") || arg.startsWith("t") || arg.startsWith("on") || arg.startsWith("+") || arg.startsWith("1"))
-		{
-			return true;
+		
+		if (TRUE_OPTIONS.contains(arg)) return Boolean.TRUE;
+		if (FALSE_OPTIONS.contains(arg)) return Boolean.FALSE;
+		
+		throw new Exception();
 	}
-		return false;
+
+	@Override
+	public Collection<String> getTabList(CommandSender sender, String arg)
+	{
+		List<String> ret = new ArrayList<String>();
+		
+		// Default yes and no.
+		ret.add("yes");
+		ret.add("no");
+		
+		// If it is empty we just want to show yes and no
+		// else we might want to show other things.
+		// We can safely add them because it is filtered.
+		if ( ! arg.isEmpty())
+		{
+			ret.add("true");
+			ret.add("false");
+			ret.add("on");
+			ret.add("off");
+		}
+		
+		return ret;
 	}
 
 }

src/com/massivecraft/massivecore/cmd/arg/ARByte.java

@@ -1,6 +1,8 @@
 package com.massivecraft.massivecore.cmd.arg;
 
-public class ARByte extends ARAbstractPrimitive<Byte>
+import org.bukkit.command.CommandSender;
+
+public class ARByte extends ARAbstractNumber<Byte>
 {
 	// -------------------------------------------- //
 	// INSTANCE & CONSTRUCT
@@ -14,13 +16,13 @@ public class ARByte extends ARAbstractPrimitive<Byte>
 	// -------------------------------------------- //
 	
 	@Override
-	public String typename()
+	public String getTypeName()
 	{
-		return "byte";
+		return "small number";
 	}
 	
 	@Override
-	public Byte convert(String arg) throws Exception
+	public Byte valueOf(String arg, CommandSender sender) throws Exception
 	{
 		return Byte.parseByte(arg);
 	}

src/com/massivecraft/massivecore/cmd/arg/ARChatColor.java

@@ -20,28 +20,19 @@ public class ARChatColor extends ARAbstractSelect<ChatColor>
 	// OVERRIDE
 	// -------------------------------------------- //
 
-	@Override
-	public String typename()
-	{
-		return "chat color";
-	}
-
 	@Override
 	public ChatColor select(String arg, CommandSender sender)
 	{
-		ChatColor ret = null;
-		
-		arg = getToCompare(arg);
+		arg = getComparable(arg);
 		
 		for (ChatColor cc : ChatColor.values())
 		{
-			String ccstr = getToCompare(cc.name());
+			String ccstr = getComparable(cc.name());
 			if ( ! ccstr.equals(arg)) continue;
-			ret = cc;
-			break;
+			return cc;
 		}
 		
-		return ret;
+		return null;
 	}
 
 	@Override
@@ -51,7 +42,20 @@ public class ARChatColor extends ARAbstractSelect<ChatColor>
 		
 		for (ChatColor cc : ChatColor.values())
 		{
-			ret.add(cc.toString()+getToCompare(cc.name()));
+			ret.add(cc.toString() + getComparable(cc.name()));
+		}
+		
+		return ret;
+	}
+	
+	@Override
+	public Collection<String> getTabList(CommandSender sender, String arg)
+	{
+		List<String> ret = new ArrayList<String>();
+		
+		for (ChatColor cc : ChatColor.values())
+		{
+			ret.add(getComparable(cc.name()));
 		}
 		
 		return ret;
@@ -63,12 +67,12 @@ public class ARChatColor extends ARAbstractSelect<ChatColor>
 	
 	// "DARK_RED" --> "darkred"
 	// "DARK RED" --> "darkred"
-	public static String getToCompare(String str)
+	public static String getComparable(String string)
 	{
-		str = str.toLowerCase();
-		str = str.replace("_", "");
-		str = str.replace(" ", "");
-		return str;
+		string = string.toLowerCase();
+		string = string.replace("_", "");
+		string = string.replace(" ", "");
+		return string;
 	}
 
 }

src/com/massivecraft/massivecore/cmd/arg/ARColl.java

@@ -19,12 +19,6 @@ public class ARColl extends ARAbstractSelect<Coll<?>>
 	// OVERRIDE
 	// -------------------------------------------- //
 
-	@Override
-	public String typename()
-	{
-		return "coll";
-	}
-
 	@Override
 	public Coll<?> select(String arg, CommandSender sender)
 	{
@@ -37,4 +31,10 @@ public class ARColl extends ARAbstractSelect<Coll<?>>
 		return Coll.getNames();
 	}
 
+	@Override
+	public Collection<String> getTabList(CommandSender sender, String arg)
+	{
+		return this.altNames(sender);
+	}
+	
 }

src/com/massivecraft/massivecore/cmd/arg/ARCombined.java

@@ -9,27 +9,27 @@ import org.bukkit.command.CommandSender;
 import com.massivecraft.massivecore.MassiveException;
 import com.massivecraft.massivecore.collections.MassiveList;
 
-public class ARCombined extends ArgReaderAbstract<List<?>>
+public class ARCombined extends ARAbstract<List<?>>
 {
 	// -------------------------------------------- //
 	// FIELDS
 	// -------------------------------------------- //
 	
-	protected List<ArgReader<?>> inners;
-	public List<ArgReader<?>> getInners() { return this.inners; }
+	protected List<AR<?>> inners;
+	public List<AR<?>> getInners() { return this.inners; }
 	
 	// -------------------------------------------- //
 	// INSTANCE & CONSTRUCT
 	// -------------------------------------------- //
 	
-	public static ARCombined get(Collection<ArgReader<?>> inners) { return new ARCombined(inners); }
-	public static ARCombined get(ArgReader<?>... inners) { return new ARCombined(inners); }
+	public static ARCombined get(Collection<AR<?>> inners) { return new ARCombined(inners); }
+	public static ARCombined get(AR<?>... inners) { return new ARCombined(inners); }
 	
-	public ARCombined(Collection<ArgReader<?>> inners)
+	public ARCombined(Collection<AR<?>> inners)
 	{
-		this.inners = new MassiveList<ArgReader<?>>(inners); 
+		this.inners = new MassiveList<AR<?>>(inners); 
 	}
-	public ARCombined(ArgReader<?>... inners)
+	public ARCombined(AR<?>... inners)
 	{
 		this(Arrays.asList(inners));
 	}
@@ -38,6 +38,14 @@ public class ARCombined extends ArgReaderAbstract<List<?>>
 	// OVERRIDE
 	// -------------------------------------------- //
 	
+	
+	//TODO: How to do this?
+	/*@Override
+	public String getTypeName()
+	{
+		
+	}*/
+	
 	@Override
 	public List<?> read(String arg, CommandSender sender) throws MassiveException
 	{
@@ -54,7 +62,7 @@ public class ARCombined extends ArgReaderAbstract<List<?>>
 		for (int i = 0; i < parts.size(); i++)
 		{
 			String part = parts.get(i);
-			ArgReader<?> argReader = this.getInners().get(i);
+			AR<?> argReader = this.getInners().get(i);
 			
 			Object asdf = argReader.read(part, sender);
 			
@@ -65,4 +73,11 @@ public class ARCombined extends ArgReaderAbstract<List<?>>
 		return ret;
 	}
 	
+	//TODO: How to do this?
+	@Override
+	public Collection<String> getTabList(CommandSender sender, String arg)
+	{
+		return null; // ???
+	}
+
 }

src/com/massivecraft/massivecore/cmd/arg/ARDate.java

@@ -2,8 +2,12 @@ package com.massivecraft.massivecore.cmd.arg;
 
 import java.text.DateFormat;
 import java.text.SimpleDateFormat;
+import java.util.Collection;
+import java.util.Collections;
 import java.util.Date;
 
+import org.bukkit.command.CommandSender;
+
 public class ARDate extends ARAbstractPrimitive<Date>
 {
 	// -------------------------------------------- //
@@ -24,15 +28,21 @@ public class ARDate extends ARAbstractPrimitive<Date>
 	// -------------------------------------------- //
 	
 	@Override
-	public String typename()
+	public String getTypeName()
 	{
 		return "YYYY-MM-DD date";
 	}
 	
 	@Override
-	public Date convert(String arg) throws Exception
+	public Date valueOf(String arg, CommandSender sender) throws Exception
 	{
 		return DATE_FORMAT.parse(arg);
 	}
 
+	@Override
+	public Collection<String> getTabList(CommandSender sender, String arg)
+	{
+		return Collections.emptySet();
+	}
+
 }

src/com/massivecraft/massivecore/cmd/arg/ARDestination.java

@@ -1,12 +1,14 @@
 package com.massivecraft.massivecore.cmd.arg;
 
+import java.util.Collection;
+
 import org.bukkit.command.CommandSender;
 
 import com.massivecraft.massivecore.MassiveException;
 import com.massivecraft.massivecore.event.EventMassiveCoreDestination;
 import com.massivecraft.massivecore.teleport.Destination;
 
-public class ARDestination extends ArgReaderAbstract<Destination>
+public class ARDestination extends ARAbstract<Destination>
 {
 	// -------------------------------------------- //
 	// INSTANCE & CONSTRUCT
@@ -36,4 +38,10 @@ public class ARDestination extends ArgReaderAbstract<Destination>
 		return ret;
 	}
 
+	@Override
+	public Collection<String> getTabList(CommandSender sender, String arg)
+	{
+		return null;
+	}
+	
 }

src/com/massivecraft/massivecore/cmd/arg/ARDifficulty.java

@@ -1,6 +1,8 @@
 package com.massivecraft.massivecore.cmd.arg;
 
 import java.util.Collection;
+import java.util.Collections;
+import java.util.List;
 
 import org.bukkit.Difficulty;
 import org.bukkit.command.CommandSender;
@@ -9,6 +11,12 @@ import com.massivecraft.massivecore.util.MUtil;
 
 public class ARDifficulty extends ARAbstractSelect<Difficulty>
 {
+	// -------------------------------------------- //
+	// CONSTANTS
+	// -------------------------------------------- //
+	
+	public static final List<String> ALT_NAMES = Collections.unmodifiableList(MUtil.list("peaceful", "easy", "normal", "hard"));
+	
 	// -------------------------------------------- //
 	// INSTANCE & CONSTRUCT
 	// -------------------------------------------- //
@@ -20,43 +28,41 @@ public class ARDifficulty extends ARAbstractSelect<Difficulty>
 	// OVERRIDE
 	// -------------------------------------------- //
 
-	@Override
-	public String typename()
-	{
-		return "difficulty";
-	}
-
 	@Override
 	public Difficulty select(String arg, CommandSender sender)
 	{
-		Difficulty ret = null;
-		
 		arg = arg.toLowerCase();
 
 		if (arg.startsWith("p"))
 		{
-			ret = Difficulty.PEACEFUL;
+			return Difficulty.PEACEFUL;
 		}
 		else if (arg.startsWith("e"))
 		{
-			ret = Difficulty.EASY;
+			return Difficulty.EASY;
 		}
 		else if (arg.startsWith("n"))
 		{
-			ret = Difficulty.NORMAL;
+			return Difficulty.NORMAL;
 		}
 		else if (arg.startsWith("h"))
 		{
-			ret = Difficulty.HARD;
+			return Difficulty.HARD;
 		}
 		
-		return ret;
+		return null;
 	}
 
 	@Override
 	public Collection<String> altNames(CommandSender sender)
 	{
-		return MUtil.list("peaceful", "easy", "normal", "hard");
+		return ALT_NAMES;
+	}
+
+	@Override
+	public Collection<String> getTabList(CommandSender sender, String arg)
+	{
+		return this.altNames(sender);
 	}
 
 }

src/com/massivecraft/massivecore/cmd/arg/ARDouble.java

@@ -1,6 +1,8 @@
 package com.massivecraft.massivecore.cmd.arg;
 
-public class ARDouble extends ARAbstractPrimitive<Double>
+import org.bukkit.command.CommandSender;
+
+public class ARDouble extends ARAbstractNumber<Double>
 {
 	// -------------------------------------------- //
 	// INSTANCE & CONSTRUCT
@@ -14,13 +16,13 @@ public class ARDouble extends ARAbstractPrimitive<Double>
 	// -------------------------------------------- //
 	
 	@Override
-	public String typename()
+	public String getTypeName()
 	{
-		return "double";
+		return "number with decimals";
 	}
 	
 	@Override
-	public Double convert(String arg) throws Exception
+	public Double valueOf(String arg, CommandSender sender) throws Exception
 	{
 		return Double.parseDouble(arg);
 	}

src/com/massivecraft/massivecore/cmd/arg/AREntityType.java

@@ -20,24 +20,19 @@ public class AREntityType extends ARAbstractSelect<EntityType>
 	// OVERRIDE
 	// -------------------------------------------- //
 
-	@Override
-	public String typename()
-	{
-		return "entity type";
-	}
-
 	@Override
 	public EntityType select(String arg, CommandSender sender)
 	{
 		arg = getComparable(arg);
 		
 		// Custom Detection
-		if (arg.contains("pig") && (arg.contains("man") || arg.contains("zombie"))) return EntityType.PIG_ZOMBIE;
+		if (arg.contains("pig") && ((arg.contains("man") || arg.contains("zombie")))) return EntityType.PIG_ZOMBIE;
 		
 		// Algorithmic General Detection
 		for (EntityType entityType : EntityType.values())
 		{
-			if (getComparable(entityType.toString()).equals(arg)) return entityType;
+			String compare = getComparable(entityType);
+			if (compare.equals(arg)) return entityType;
 		}
 		
 		// Nothing found
@@ -50,13 +45,30 @@ public class AREntityType extends ARAbstractSelect<EntityType>
 		List<String> ret = new ArrayList<String>();
 		for (EntityType entityType : EntityType.values())
 		{
-			ret.add(getComparable(entityType.toString()));
+			ret.add(getComparable(entityType));
 		}
 		return ret;
 	}
 	
+	@Override
+	public Collection<String> getTabList(CommandSender sender, String arg)
+	{
+		return this.altNames(sender);
+	}
+	
+	// -------------------------------------------- //
+	// UTIL
+	// -------------------------------------------- //
+	
+	public static String getComparable(EntityType entityType)
+	{
+		if (entityType == null) return null;
+		return getComparable(entityType.toString());
+	}
+	
 	public static String getComparable(String string)
 	{
+		if (string == null) return null;
 		return string.toLowerCase().replaceAll("[_\\-\\s]+", "");
 	}
 	

src/com/massivecraft/massivecore/cmd/arg/AREnum.java

@@ -1,6 +1,5 @@
 package com.massivecraft.massivecore.cmd.arg;
 
-import java.lang.reflect.Method;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.List;
@@ -28,6 +27,7 @@ public class AREnum<T> extends ARAbstractSelect<T>
 	
 	public AREnum(Class<T> clazz)
 	{
+		if ( ! clazz.isEnum()) throw new IllegalArgumentException("passed clazz param must be an enum");
 		this.clazz = clazz;
 	}
 			
@@ -36,7 +36,7 @@ public class AREnum<T> extends ARAbstractSelect<T>
 	// -------------------------------------------- //
 	
 	@Override
-	public String typename()
+	public String getTypeName()
 	{
 		return Txt.getNicedEnumString(clazz.getSimpleName());
 	}
@@ -50,63 +50,67 @@ public class AREnum<T> extends ARAbstractSelect<T>
 		
 		// Algorithmic General Detection
 		
-		int startswithCount = 0;
-		T startswith = null;
-		for (T value : getEnumValues(this.clazz))
+		T startsWith = null;
+		for (T value : getEnumValues(clazz))
 		{
-			String comparable = getComparable(value.toString());
+			String comparable = getComparable(value);
 			if (comparable.equals(arg)) return value;
 			if (comparable.startsWith(arg))
 			{
-				startswith = value;
-				startswithCount++;
-			}
-		}
+				// If there already were a result
+				// we have multiple results and stop.
+				if (startsWith != null) return null;
 				
-		if (startswithCount == 1)
-		{
-			return startswith;
+				// Else we set the result.
+				startsWith = value;
+			}
 		}
 		
 		// Nothing found
-		return null;
+		return startsWith;
 	}
 
 	@Override
 	public Collection<String> altNames(CommandSender sender)
 	{
 		List<String> ret = new ArrayList<String>();
-		for (T value : getEnumValues(this.clazz))
+		for (T value : getEnumValues(clazz))
 		{
-			ret.add(getComparable(value.toString()));
+			ret.add(getComparable(value));
 		}
 		return ret;
 	}
 
+	@Override
+	public Collection<String> getTabList(CommandSender sender, String arg)
+	{
+		return this.altNames(sender);
+	}
+	
 	// -------------------------------------------- //
 	// UTIL
 	// -------------------------------------------- //
 	
+	public static <T> T[] getEnumValues(Class<T> clazz)
+	{
+		if ( ! clazz.isEnum()) throw new IllegalArgumentException("passed clazz param must be an enum");
+		
+		T[] ret = clazz.getEnumConstants();
+		if (ret == null) throw new RuntimeException("failed to retrieve enum constants");
+		
+		return ret;
+	}
+	
+	public static String getComparable(Object value)
+	{
+		if (value == null) return null;
+		return getComparable(value.toString());
+	}
+	
 	public static String getComparable(String string)
 	{
+		if (string == null) return null;
 		return string.toLowerCase().replaceAll("[_\\-\\s]+", "");
 	}
 
-	@SuppressWarnings("unchecked")
-	public static <T> T[] getEnumValues(Class<T> clazz)
-	{
-		try
-		{
-			Method method = clazz.getMethod("values");
-			Object o = method.invoke(null);
-			return (T[]) o;
-		}
-		catch (Exception e)
-		{
-			// TODO Auto-generated catch block
-			e.printStackTrace();
-			return null;
-		}
-	}
-	
 }

src/com/massivecraft/massivecore/cmd/arg/AREnvironment.java

@@ -1,7 +1,10 @@
 package com.massivecraft.massivecore.cmd.arg;
 
 import java.util.Collection;
+import java.util.Collections;
+import java.util.List;
 
+import org.apache.commons.lang.StringUtils;
 import org.bukkit.World.Environment;
 import org.bukkit.command.CommandSender;
 
@@ -9,6 +12,12 @@ import com.massivecraft.massivecore.util.MUtil;
 
 public class AREnvironment extends ARAbstractSelect<Environment>
 {
+	// -------------------------------------------- //
+	// CONSTANTS
+	// -------------------------------------------- //
+	
+	public static final List<String> ALT_NAMES = Collections.unmodifiableList(MUtil.list("normal", "end", "nether"));
+	
 	// -------------------------------------------- //
 	// INSTANCE & CONSTRUCT
 	// -------------------------------------------- //
@@ -20,45 +29,64 @@ public class AREnvironment extends ARAbstractSelect<Environment>
 	// OVERRIDE
 	// -------------------------------------------- //
 
-	@Override
-	public String typename()
-	{
-		return "environment";
-	}
-
 	@Override
 	public Environment select(String arg, CommandSender sender)
 	{
-		Environment ret = null;
-		
 		// "THE_END" --> "end"
-		arg = arg.toLowerCase();
-		arg = arg.replace("_", "");
-		arg = arg.replace("the", "");
+		arg = getComparable(arg);
 		
 		if (arg.startsWith("no") || arg.startsWith("d"))
 		{
 			// "normal" or "default"
-			ret = Environment.NORMAL;
+			return Environment.NORMAL;
 		}
 		else if (arg.startsWith("ne"))
 		{
 			// "nether"
-			ret = Environment.NETHER;
+			return Environment.NETHER;
 		}
 		else if (arg.startsWith("e"))
 		{
 			// "end"
-			ret = Environment.THE_END;
+			return Environment.THE_END;
 		}
 		
-		return ret;
+		return null;
 	}
 
 	@Override
 	public Collection<String> altNames(CommandSender sender)
 	{
-		return MUtil.list("normal", "end", "nether");
+		return ALT_NAMES;
+	}
+	
+	@Override
+	public Collection<String> getTabList(CommandSender sender, String arg)
+	{
+		Collection<String> ret = this.altNames(sender);
+		
+		// The_end or the_nether
+		if (StringUtils.startsWithIgnoreCase(arg, "t"))
+		{
+			ret.add("the_end");
+			ret.add("the_nether");
+		}
+		
+		return ret;
+	}
+	
+	// -------------------------------------------- //
+	// UTIL
+	// -------------------------------------------- //
+	
+	public static String getComparable(String str)
+	{
+		str = str.toLowerCase();
+		str = str.replace(" ", "");
+		str = str.replace("_", "");
+		str = str.replace("the", "");
+		
+		return str;
 	}
 	
 }

src/com/massivecraft/massivecore/cmd/arg/ARFloat.java

@@ -1,6 +1,8 @@
 package com.massivecraft.massivecore.cmd.arg;
 
-public class ARFloat extends ARAbstractPrimitive<Float>
+import org.bukkit.command.CommandSender;
+
+public class ARFloat extends ARAbstractNumber<Float>
 {
 	// -------------------------------------------- //
 	// INSTANCE & CONSTRUCT
@@ -14,13 +16,13 @@ public class ARFloat extends ARAbstractPrimitive<Float>
 	// -------------------------------------------- //
 	
 	@Override
-	public String typename()
+	public String getTypeName()
 	{
-		return "integer";
+		return "number with decimals";
 	}
 	
 	@Override
-	public Float convert(String arg) throws Exception
+	public Float valueOf(String arg, CommandSender sender) throws Exception
 	{
 		return Float.parseFloat(arg);
 	}

src/com/massivecraft/massivecore/cmd/arg/ARGameMode.java

@@ -1,11 +1,13 @@
 package com.massivecraft.massivecore.cmd.arg;
 
+import java.util.ArrayList;
 import java.util.Collection;
+import java.util.List;
 
 import org.bukkit.GameMode;
 import org.bukkit.command.CommandSender;
 
-import com.massivecraft.massivecore.util.MUtil;
+import com.massivecraft.massivecore.util.Txt;
 
 public class ARGameMode extends ARAbstractSelect<GameMode>
 {
@@ -20,39 +22,55 @@ public class ARGameMode extends ARAbstractSelect<GameMode>
 	// OVERRIDE
 	// -------------------------------------------- //
 
-	@Override
-	public String typename()
-	{
-		return "game mode";
-	}
-
 	@Override
 	public GameMode select(String arg, CommandSender sender)
 	{
-		GameMode ret = null;
+		arg = getComparable(arg);
 		
-		arg = arg.toLowerCase();
+		if (arg.length() < 2) return null; // Some gamemodes have the same beginning character. So we need atleast 2 characters.
 		
-		if (arg.startsWith("s") || arg.equals("0"))
+		for (GameMode gm : GameMode.values())
 		{
-			ret = GameMode.SURVIVAL;
-		}
-		else if (arg.startsWith("c") || arg.equals("1"))
-		{
-			ret = GameMode.CREATIVE;
-		}
-		else if (arg.startsWith("a") || arg.equals("2"))
-		{
-			ret = GameMode.ADVENTURE;
+			// Comparable
+			String compare = getComparable(gm);
+			
+			if (compare.startsWith(arg)) return gm;
 		}
 
-		return ret;
+		return null;
 	}
 	
 	@Override
 	public Collection<String> altNames(CommandSender sender)
 	{
-		return MUtil.list("survival", "creative", "adventure");
+		List<String> ret = new ArrayList<String>();
+		for (GameMode gm : GameMode.values())
+		{
+			ret.add(Txt.getNicedEnum(gm));
+		}
+		return ret;
+	}
+	
+	@Override
+	public Collection<String> getTabList(CommandSender sender, String arg)
+	{
+		return this.altNames(sender);
+	}
+	
+	// -------------------------------------------- //
+	// UTIL
+	// -------------------------------------------- //
+
+	public static String getComparable(GameMode gamemode)
+	{
+		if (gamemode == null) return null;
+		return getComparable(gamemode.name());
+	}
+	
+	public static String getComparable(String string)
+	{
+		if (string == null) return null;
+		return string.toLowerCase();
 	}
 
 }

src/com/massivecraft/massivecore/cmd/arg/ARInteger.java

@@ -1,6 +1,8 @@
 package com.massivecraft.massivecore.cmd.arg;
 
-public class ARInteger extends ARAbstractPrimitive<Integer>
+import org.bukkit.command.CommandSender;
+
+public class ARInteger extends ARAbstractNumber<Integer>
 {
 	// -------------------------------------------- //
 	// INSTANCE & CONSTRUCT
@@ -14,13 +16,13 @@ public class ARInteger extends ARAbstractPrimitive<Integer>
 	// -------------------------------------------- //
 	
 	@Override
-	public String typename()
+	public String getTypeName()
 	{
-		return "integer";
+		return "number";
 	}
 
 	@Override
-	public Integer convert(String arg) throws Exception
+	public Integer valueOf(String arg, CommandSender sender) throws Exception
 	{
 		return Integer.parseInt(arg);
 	}

src/com/massivecraft/massivecore/cmd/arg/ARList.java

@@ -1,31 +1,32 @@
 package com.massivecraft.massivecore.cmd.arg;
 
 import java.util.ArrayList;
+import java.util.Collection;
 import java.util.List;
 
 import org.bukkit.command.CommandSender;
 
 import com.massivecraft.massivecore.MassiveException;
 
-public class ARList<T> extends ArgReaderAbstract<List<T>>
+public class ARList<T> extends ARAbstract<List<T>>
 {
 	// -------------------------------------------- //
 	// FIELDS
 	// -------------------------------------------- //
 	
-	protected ArgReader<T> innerArgReader;
-	public ArgReader<T> getInnerArgReader() { return this.innerArgReader; }
+	protected AR<T> innerArgReader;
+	public AR<T> getInnerArgReader() { return this.innerArgReader; }
 	
 	// -------------------------------------------- //
 	// INSTANCE & CONSTRUCT
 	// -------------------------------------------- //
 	
-	public static <T> ARList<T> get(ArgReader<T> innerArgReader)
+	public static <T> ARList<T> get(AR<T> innerArgReader)
 	{
 		return new ARList<T>(innerArgReader);
 	}
 	
-	public ARList(ArgReader<T> innerArgReader)
+	public ARList(AR<T> innerArgReader)
 	{
 		this.innerArgReader = innerArgReader;
 	}
@@ -34,6 +35,12 @@ public class ARList<T> extends ArgReaderAbstract<List<T>>
 	// OVERRIDE
 	// -------------------------------------------- //
 	
+	@Override
+	public String getTypeName()
+	{
+		return innerArgReader.getTypeName();
+	}
+
 	// NOTE: Must be used with argConcatFrom and setErrorOnTooManyArgs(false).
 	@Override
 	public List<T> read(String arg, CommandSender sender) throws MassiveException
@@ -56,4 +63,10 @@ public class ARList<T> extends ArgReaderAbstract<List<T>>
 		return ret;
 	}
 
+	@Override
+	public Collection<String> getTabList(CommandSender sender, String arg)
+	{
+		return this.getInnerArgReader().getTabList(sender, arg);
+	}
+
 }

src/com/massivecraft/massivecore/cmd/arg/ARLong.java

@@ -1,6 +1,8 @@
 package com.massivecraft.massivecore.cmd.arg;
 
-public class ARLong extends ARAbstractPrimitive<Long>
+import org.bukkit.command.CommandSender;
+
+public class ARLong extends ARAbstractNumber<Long>
 {
 	// -------------------------------------------- //
 	// INSTANCE & CONSTRUCT
@@ -14,13 +16,13 @@ public class ARLong extends ARAbstractPrimitive<Long>
 	// -------------------------------------------- //
 	
 	@Override
-	public String typename()
+	public String getTypeName()
 	{
-		return "long";
+		return "number";
 	}
 
 	@Override
-	public Long convert(String arg) throws Exception
+	public Long valueOf(String arg, CommandSender sender) throws Exception
 	{
 		return Long.parseLong(arg);
 	}

src/com/massivecraft/massivecore/cmd/arg/ARMaterial.java

@@ -1,11 +1,15 @@
 package com.massivecraft.massivecore.cmd.arg;
 
+import java.util.Collection;
+import java.util.Set;
+import java.util.TreeSet;
+
 import org.bukkit.Material;
 import org.bukkit.command.CommandSender;
 
 import com.massivecraft.massivecore.MassiveException;
 
-public class ARMaterial extends ArgReaderAbstract<Material>
+public class ARMaterial extends ARAbstract<Material>
 {
 	// -------------------------------------------- //
 	// INSTANCE & CONSTRUCT
@@ -24,10 +28,22 @@ public class ARMaterial extends ArgReaderAbstract<Material>
 		Material ret = Material.matchMaterial(arg);
 		if (ret == null)
 		{
-			MassiveException exception = new MassiveException();
-			exception.addMsg("<b>No material matches <h>%s<b>.", arg);
-			exception.addMsg("<i>Suggestion: <aqua>http://www.minecraftwiki.net/wiki/Data_values");
-			throw exception;
+			throw new MassiveException()
+			.addMsg("<b>No material matches <h>%s<b>.", arg)
+			.addMsg("<i>https://hub.spigotmc.org/stash/projects/SPIGOT/repos/bukkit/browse/src/main/java/org/bukkit/Material.java");
+		}
+		
+		return ret;
+	}
+	
+	@Override
+	public Collection<String> getTabList(CommandSender sender, String arg)
+	{
+		Set<String> ret = new TreeSet<String>(String.CASE_INSENSITIVE_ORDER);
+		
+		for (Material material : Material.values())
+		{
+			ret.add(material.name());
 		}
 		
 		return ret;

src/com/massivecraft/massivecore/cmd/arg/ARMillisDiff.java

@@ -1,11 +1,13 @@
 package com.massivecraft.massivecore.cmd.arg;
 
+import java.util.Collection;
+import java.util.Collections;
+
 import org.bukkit.command.CommandSender;
 
-import com.massivecraft.massivecore.MassiveException;
 import com.massivecraft.massivecore.util.TimeDiffUtil;
 
-public class ARMillisDiff extends ArgReaderAbstract<Long>
+public class ARMillisDiff extends ARAbstractException<Long>
 {
 	// -------------------------------------------- //
 	// INSTANCE & CONSTRUCT
@@ -19,19 +21,21 @@ public class ARMillisDiff extends ArgReaderAbstract<Long>
 	// -------------------------------------------- //
 	
 	@Override
-	public Long read(String arg, CommandSender sender) throws MassiveException
+	public String getTypeName()
 	{
-		Long ret;
-		try
-		{
-			ret = TimeDiffUtil.millis(arg);
-		}
-		catch (Exception e)
-		{
-			throw new MassiveException().addMsg("<b>%s", e.getMessage());
+		return "time amount";
 	}
 	
-		return ret;
+	@Override
+	public Long valueOf(String arg, CommandSender sender) throws Exception
+	{
+		return TimeDiffUtil.millis(arg);
+	}
+
+	@Override
+	public Collection<String> getTabList(CommandSender sender, String arg)
+	{
+		return Collections.emptySet();
 	}
 
 }

src/com/massivecraft/massivecore/cmd/arg/ARMultiverse.java

@@ -21,12 +21,6 @@ public class ARMultiverse extends ARAbstractSelect<Multiverse>
 	// OVERRIDE
 	// -------------------------------------------- //
 
-	@Override
-	public String typename()
-	{
-		return "multiverse";
-	}
-
 	@Override
 	public Multiverse select(String arg, CommandSender sender)
 	{
@@ -45,4 +39,10 @@ public class ARMultiverse extends ARAbstractSelect<Multiverse>
 		return MultiverseColl.get().getIds();
 	}
 	
+	@Override
+	public Collection<String> getTabList(CommandSender sender, String arg)
+	{
+		return this.altNames(sender);
+	}
+
 }

src/com/massivecraft/massivecore/cmd/arg/ARNullable.java

@@ -1,23 +1,26 @@
 package com.massivecraft.massivecore.cmd.arg;
 
+import java.util.Collection;
+
 import org.bukkit.command.CommandSender;
 
 import com.massivecraft.massivecore.MassiveCore;
 import com.massivecraft.massivecore.MassiveException;
 
-public class ARNullable<T> extends ArgReaderAbstract<T>
+public class ARNullable<T> extends ARAbstract<T>
 {
 	// -------------------------------------------- //
 	// INSTANCE & CONSTRUCT
 	// -------------------------------------------- //
 	
-	public static <T> ARNullable<T> get(ArgReader<T> inner)
+	public static <T> ARNullable<T> get(AR<T> inner)
 	{
 		return new ARNullable<T>(inner);
 	}
 	
-	public ARNullable(ArgReader<T> inner)
+	public ARNullable(AR<T> inner)
 	{
+		if (inner == null) throw new IllegalArgumentException("inner param is null");
 		this.inner = inner;
 	}
 	
@@ -25,13 +28,19 @@ public class ARNullable<T> extends ArgReaderAbstract<T>
 	// FIELDS
 	// -------------------------------------------- //
 	
-	protected ArgReader<T> inner;
-	public ArgReader<T> getInner() { return this.inner; }
+	protected AR<T> inner;
+	public AR<T> getInner() { return this.inner; }
 	
 	// -------------------------------------------- //
 	// OVERRIDE
 	// -------------------------------------------- //
 
+	@Override
+	public String getTypeName()
+	{
+		return this.getInner().getTypeName();
+	}
+	
 	@Override
 	public T read(String arg, CommandSender sender) throws MassiveException
 	{
@@ -40,4 +49,10 @@ public class ARNullable<T> extends ArgReaderAbstract<T>
 		return this.getInner().read(arg, sender);
 	}
 
+	@Override
+	public Collection<String> getTabList(CommandSender sender, String arg)
+	{
+		return this.getInner().getTabList(sender, arg);
+	}
+
 }

src/com/massivecraft/massivecore/cmd/arg/ARPS.java

@@ -1,6 +1,7 @@
 package com.massivecraft.massivecore.cmd.arg;
 
 import java.util.Arrays;
+import java.util.Collection;
 import java.util.List;
 
 import org.bukkit.command.CommandSender;
@@ -11,7 +12,7 @@ import com.massivecraft.massivecore.ps.PS;
 import com.massivecraft.massivecore.ps.PSBuilder;
 import com.mysql.jdbc.StringUtils;
 
-public class ARPS extends ArgReaderAbstract<PS>
+public class ARPS extends ARAbstract<PS>
 {
 	// -------------------------------------------- //
 	// INSTANCE & CONSTRUCT
@@ -203,6 +204,12 @@ public class ARPS extends ArgReaderAbstract<PS>
 		return ret.build();
 	}
 
+	@Override
+	public Collection<String> getTabList(CommandSender sender, String arg)
+	{
+		return null;
+	}
+	
 	public static String getValue(String entry, String... prefixes)
 	{
 		for (String prefix : prefixes)

src/com/massivecraft/massivecore/cmd/arg/ARPermission.java

@@ -1,12 +1,16 @@
 package com.massivecraft.massivecore.cmd.arg;
 
+import java.util.Collection;
+import java.util.Set;
+import java.util.TreeSet;
+
 import org.bukkit.Bukkit;
 import org.bukkit.command.CommandSender;
 import org.bukkit.permissions.Permission;
 
 import com.massivecraft.massivecore.MassiveException;
 
-public class ARPermission extends ArgReaderAbstract<Permission>
+public class ARPermission extends ARAbstract<Permission>
 {
 	// -------------------------------------------- //
 	// INSTANCE & CONSTRUCT
@@ -22,20 +26,25 @@ public class ARPermission extends ArgReaderAbstract<Permission>
 	@Override
 	public Permission read(String arg, CommandSender sender) throws MassiveException
 	{
-		Permission ret = null;
-		
 		for (Permission permission : Bukkit.getPluginManager().getPermissions())
 		{
 			if ( ! permission.getName().equals(arg)) continue;
-			ret = permission;
-			break;
+			return permission;
 		}
 		
-		if (ret == null)
-		{
 		throw new MassiveException().addMsg("<b>No permission with the name \"<h>%s<b>\" was found.", arg);
 	}
 	
+	@Override
+	public Collection<String> getTabList(CommandSender sender, String arg)
+	{
+		Set<String> ret = new TreeSet<String>(String.CASE_INSENSITIVE_ORDER);
+		
+		for (Permission perm : Bukkit.getPluginManager().getPermissions())
+		{
+			ret.add(perm.getName());
+		}
+		
 		return ret;
 	}
 

src/com/massivecraft/massivecore/cmd/arg/ARPlayer.java

@@ -1,9 +1,16 @@
 package com.massivecraft.massivecore.cmd.arg;
 
+import java.util.Collection;
+import java.util.Set;
+import java.util.TreeSet;
+
+import org.bukkit.command.CommandSender;
 import org.bukkit.entity.Player;
 
+import com.massivecraft.massivecore.mixin.Mixin;
 import com.massivecraft.massivecore.store.SenderIdSourceMixinAllSenderIds;
 import com.massivecraft.massivecore.util.IdUtil;
+import com.massivecraft.massivecore.util.MUtil;
 
 public class ARPlayer extends ARSenderIdAbstract<Player>
 {
@@ -25,8 +32,23 @@ public class ARPlayer extends ARSenderIdAbstract<Player>
 	@Override
 	public Player getResultForSenderId(String senderId)
 	{
-		if (senderId == null) return null;
+		// Null check is done in IdUtil :)
 		return IdUtil.getPlayer(senderId);
 	}
 
+	@Override
+	public Collection<String> getTabList(CommandSender sender, String arg)
+	{
+		Set<String> ret = new TreeSet<String>(String.CASE_INSENSITIVE_ORDER);
+		
+		for (String name : IdUtil.getOnlineNames())
+		{
+			if ( ! MUtil.isValidPlayerName(name)) continue;
+			if ( ! Mixin.canSee(sender, name)) continue;
+			ret.add(name);
+		}
+		
+		return ret;
+	}
+
 }

src/com/massivecraft/massivecore/cmd/arg/ARPotionEffectType.java

@@ -22,12 +22,6 @@ public class ARPotionEffectType extends ARAbstractSelect<PotionEffectType>
 	// OVERRIDE
 	// -------------------------------------------- //
 
-	@Override
-	public String typename()
-	{
-		return "potion effect type";
-	}
-
 	@Override
 	public PotionEffectType select(String str, CommandSender sender) throws MassiveException
 	{
@@ -65,6 +59,16 @@ public class ARPotionEffectType extends ARAbstractSelect<PotionEffectType>
 		return ret;
 	}
 
+	@Override
+	public Collection<String> getTabList(CommandSender sender, String arg)
+	{
+		return this.altNames(sender);
+	}
+	
+	// -------------------------------------------- //
+	// UTIL
+	// -------------------------------------------- //
+	
 	public static String getComparable(PotionEffectType potionEffectType)
 	{
 		if (potionEffectType == null) return null;

src/com/massivecraft/massivecore/cmd/arg/ARPotionEffectWrap.java

@@ -1,5 +1,6 @@
 package com.massivecraft.massivecore.cmd.arg;
 
+import java.util.Collection;
 import java.util.List;
 
 import org.bukkit.command.CommandSender;
@@ -8,7 +9,7 @@ import org.bukkit.potion.PotionEffectType;
 import com.massivecraft.massivecore.MassiveException;
 import com.massivecraft.massivecore.PotionEffectWrap;
 
-public class ARPotionEffectWrap extends ArgReaderAbstract<PotionEffectWrap>
+public class ARPotionEffectWrap extends ARAbstract<PotionEffectWrap>
 {
 	// -------------------------------------------- //
 	// INSTANCE & CONSTRUCT
@@ -77,4 +78,10 @@ public class ARPotionEffectWrap extends ArgReaderAbstract<PotionEffectWrap>
 		return ret;
 	}
 
+	@Override
+	public Collection<String> getTabList(CommandSender sender, String arg)
+	{
+		return ARPotionEffectType.get().getTabList(sender, arg);
+	}
+	
 }

src/com/massivecraft/massivecore/cmd/arg/ARSender.java

@@ -1,7 +1,12 @@
 package com.massivecraft.massivecore.cmd.arg;
 
+import java.util.Collection;
+import java.util.Set;
+import java.util.TreeSet;
+
 import org.bukkit.command.CommandSender;
 
+import com.massivecraft.massivecore.mixin.Mixin;
 import com.massivecraft.massivecore.store.SenderIdSourceMixinAllSenderIds;
 import com.massivecraft.massivecore.util.IdUtil;
 
@@ -25,8 +30,22 @@ public class ARSender extends ARSenderIdAbstract<CommandSender>
 	@Override
 	public CommandSender getResultForSenderId(String senderId)
 	{
-		if (senderId == null) return null;
+		//Null check is done in IdUtil
 		return IdUtil.getSender(senderId);
 	}
 	
+	@Override
+	public Collection<String> getTabList(CommandSender sender, String arg)
+	{
+		Set<String> ret = new TreeSet<String>(String.CASE_INSENSITIVE_ORDER);
+		
+		for (String name : IdUtil.getOnlineNames())
+		{
+			if ( ! Mixin.canSee(sender, name)) continue;
+			ret.add(name);
+		}
+		
+		return ret;
+	}
+
 }

src/com/massivecraft/massivecore/cmd/arg/ARSenderEntity.java

@@ -1,7 +1,15 @@
 package com.massivecraft.massivecore.cmd.arg;
 
+import java.util.Collection;
+import java.util.Set;
+import java.util.TreeSet;
+
+import org.bukkit.command.CommandSender;
+
+import com.massivecraft.massivecore.mixin.Mixin;
 import com.massivecraft.massivecore.store.SenderColl;
 import com.massivecraft.massivecore.store.SenderEntity;
+import com.massivecraft.massivecore.util.IdUtil;
 
 public class ARSenderEntity<T extends SenderEntity<T>> extends ARSenderIdAbstract<T>
 {
@@ -41,8 +49,22 @@ public class ARSenderEntity<T extends SenderEntity<T>> extends ARSenderIdAbstrac
 	@Override
 	public T getResultForSenderId(String senderId)
 	{
-		if (senderId == null) return null;
+		// Null check is done in SenderColl & IdUtil :)
 		return this.coll.get(senderId);
 	}
 
+	@Override
+	public Collection<String> getTabList(CommandSender sender, String arg)
+	{
+		Set<String> ret = new TreeSet<String>(String.CASE_INSENSITIVE_ORDER);
+		
+		for (String name : IdUtil.getOnlineNames())
+		{
+			if ( ! Mixin.canSee(sender, name)) continue;
+			ret.add(name);
+		}
+		
+		return ret;
+	}
+
 }

src/com/massivecraft/massivecore/cmd/arg/ARSenderId.java

@@ -1,7 +1,15 @@
 package com.massivecraft.massivecore.cmd.arg;
 
+import java.util.Collection;
+import java.util.Set;
+import java.util.TreeSet;
+
+import org.bukkit.command.CommandSender;
+
+import com.massivecraft.massivecore.mixin.Mixin;
 import com.massivecraft.massivecore.store.SenderIdSource;
 import com.massivecraft.massivecore.store.SenderIdSourceMixinAllSenderIds;
+import com.massivecraft.massivecore.util.IdUtil;
 
 public class ARSenderId extends ARSenderIdAbstract<String>
 {
@@ -43,4 +51,18 @@ public class ARSenderId extends ARSenderIdAbstract<String>
 		return senderId;
 	}
 
+	@Override
+	public Collection<String> getTabList(CommandSender sender, String arg)
+	{
+		Set<String> ret = new TreeSet<String>(String.CASE_INSENSITIVE_ORDER);
+		
+		for (String id : IdUtil.getOnlineIds())
+		{
+			if ( ! Mixin.canSee(sender, id)) continue;
+			ret.add(id);
+		}
+		
+		return ret;
+	}
+
 }

src/com/massivecraft/massivecore/cmd/arg/ARSenderIdAbstract.java

@@ -9,7 +9,7 @@ import com.massivecraft.massivecore.mixin.Mixin;
 import com.massivecraft.massivecore.store.SenderIdSource;
 import com.massivecraft.massivecore.util.IdUtil;
 
-public abstract class ARSenderIdAbstract<T> extends ArgReaderAbstract<T>
+public abstract class ARSenderIdAbstract<T> extends ARAbstract<T>
 {
 	// -------------------------------------------- //
 	// FIELDS
@@ -43,6 +43,13 @@ public abstract class ARSenderIdAbstract<T> extends ArgReaderAbstract<T>
 	// OVERRIDE
 	// -------------------------------------------- //
 	
+	@Override
+	public String getTypeName()
+	{
+		if (online) return "online player";
+		else return "player";
+	}
+	
 	@Override
 	public T read(String arg, CommandSender sender) throws MassiveException
 	{
@@ -60,7 +67,7 @@ public abstract class ARSenderIdAbstract<T> extends ArgReaderAbstract<T>
 		if (ret == null)
 		{
 			// No alternatives found
-			throw new MassiveException().addMsg("<b>No player matches \"<h>%s<b>\".", arg);
+			throw new MassiveException().addMsg("<b>No %s matches \"<h>%s<b>\".", this.getTypeName(), arg);
 		}
 	
 		// Return Ret
@@ -83,7 +90,7 @@ public abstract class ARSenderIdAbstract<T> extends ArgReaderAbstract<T>
 		for (Collection<String> coll : this.source.getSenderIdCollections())
 		{
 			// If the senderId exists ...
-			if (!coll.contains(senderId)) continue;
+			if ( ! coll.contains(senderId)) continue;
 			
 			// ... and the online check passes ...
 			if (this.online && !Mixin.isOnline(senderId)) continue;

src/com/massivecraft/massivecore/cmd/arg/ARSet.java

@@ -1,35 +1,36 @@
 package com.massivecraft.massivecore.cmd.arg;
 
+import java.util.Collection;
 import java.util.LinkedHashSet;
 import java.util.Set;
 
 import org.bukkit.command.CommandSender;
 
 import com.massivecraft.massivecore.MassiveException;
-import com.massivecraft.massivecore.util.Txt;
+import com.massivecraft.massivecore.mixin.Mixin;
 
-public class ARSet<T> extends ArgReaderAbstract<Set<T>>
+public class ARSet<T> extends ARAbstract<Set<T>>
 {
 	// -------------------------------------------- //
 	// FIELDS
 	// -------------------------------------------- //
 	
-	protected ArgReader<T> innerArgReader;
-	public ArgReader<T> getInnerArgReader() { return this.innerArgReader; }
+	private final AR<T> innerArgReader;
+	public AR<T> getInnerArgReader() { return this.innerArgReader; }
 	
-	protected boolean warnOnDuplicates;
+	private final boolean warnOnDuplicates;
 	public boolean getWarnOnDuplicate() { return warnOnDuplicates; }
 	
 	// -------------------------------------------- //
 	// INSTANCE & CONSTRUCT
 	// -------------------------------------------- //
 	
-	public static <T> ARSet<T> get(ArgReader<T> innerArgReader, boolean warnOnDuplicates)
+	public static <T> ARSet<T> get(AR<T> innerArgReader, boolean warnOnDuplicates)
 	{
 		return new ARSet<T>(innerArgReader, warnOnDuplicates);
 	}
 	
-	public ARSet(ArgReader<T> innerArgReader, boolean warnOnDuplicates)
+	public ARSet(AR<T> innerArgReader, boolean warnOnDuplicates)
 	{
 		this.innerArgReader = innerArgReader;
 		this.warnOnDuplicates = warnOnDuplicates;
@@ -39,6 +40,12 @@ public class ARSet<T> extends ArgReaderAbstract<Set<T>>
 	// OVERRIDE
 	// -------------------------------------------- //
 	
+	@Override
+	public String getTypeName()
+	{
+		return innerArgReader.getTypeName();
+	}
+
 	// NOTE: Must be used with argConcatFrom and setErrorOnTooManyArgs(false).
 	@Override
 	public Set<T> read(String arg, CommandSender sender) throws MassiveException
@@ -61,11 +68,17 @@ public class ARSet<T> extends ArgReaderAbstract<Set<T>>
 		
 		if (warnOnDuplicates && duplicates)
 		{
-			sender.sendMessage(Txt.parse("<i>Some duplicate arguments were removed"));
+			Mixin.msgOne(sender, "<i>Some duplicate command input were removed.");
 		}
 		
 		// Return Ret
 		return ret;
 	}
 
+	@Override
+	public Collection<String> getTabList(CommandSender sender, String arg)
+	{
+		return innerArgReader.getTabList(sender, arg);
+	}
+
 }

src/com/massivecraft/massivecore/cmd/arg/ARSound.java

@@ -1,11 +1,15 @@
 package com.massivecraft.massivecore.cmd.arg;
 
+import java.util.Collection;
+import java.util.Set;
+import java.util.TreeSet;
+
 import org.bukkit.Sound;
 import org.bukkit.command.CommandSender;
 
 import com.massivecraft.massivecore.MassiveException;
 
-public class ARSound extends ArgReaderAbstract<Sound>
+public class ARSound extends ARAbstract<Sound>
 {
 	// -------------------------------------------- //
 	// INSTANCE & CONSTRUCT
@@ -24,31 +28,52 @@ public class ARSound extends ArgReaderAbstract<Sound>
 		Sound result = getSoundFromString(arg);
 		if (result == null)
 		{
-			MassiveException errors = new MassiveException();
-			errors.addMsg("<b>No sound matches \"<h>%s<b>\".", arg);
-			errors.addMsg("<aqua>https://hub.spigotmc.org/stash/projects/SPIGOT/repos/bukkit/browse/src/main/java/org/bukkit/Sound.java");
-			throw errors;
+			throw new MassiveException()
+			.addMsg("<b>No sound matches \"<h>%s<b>\".", arg)
+			.addMsg("<aqua>https://hub.spigotmc.org/stash/projects/SPIGOT/repos/bukkit/browse/src/main/java/org/bukkit/Sound.java");
 		}
 		return result;
 	}
 	
+	@Override
+	public Collection<String> getTabList(CommandSender sender, String arg)
+	{
+		Set<String> ret = new TreeSet<String>(String.CASE_INSENSITIVE_ORDER);
+		
+		for (Sound sound : Sound.values())
+		{
+			String name = getComparable(sound);
+			ret.add(name);
+		}
+		
+		return ret;
+	}
+	
 	// -------------------------------------------- //
 	// UTIL
 	// -------------------------------------------- //
 	
-	public static Sound getSoundFromString(String string)
+	public static Sound getSoundFromString(String str)
 	{
-		String string1 = getCompareString(string);
+		if (str == null) return null;
+		String string1 = getComparable(str);
 		for (Sound sound : Sound.values())
 		{
-			String string2 = getCompareString(sound.name());
-			if (string1.equals(string2)) return sound;
+			String compare = getComparable(sound);
+			if (string1.equals(compare)) return sound;
 		}
 		return null;
 	}
 	
-	public static String getCompareString(String string)
+	public static String getComparable(Sound sound)
 	{
+		if (sound == null) return null;
+		return getComparable(sound.name());
+	}
+	
+	public static String getComparable(String string)
+	{
+		if (string == null) return null;
 		string = string.toLowerCase();
 		string = string.replaceAll("[^a-zA-Z0-9]", "");
 		return string;

src/com/massivecraft/massivecore/cmd/arg/ARSoundEffect.java

@@ -1,11 +1,14 @@
 package com.massivecraft.massivecore.cmd.arg;
 
+import java.util.Collection;
+import java.util.Set;
+
 import org.bukkit.command.CommandSender;
 
-import com.massivecraft.massivecore.MassiveException;
 import com.massivecraft.massivecore.SoundEffect;
+import com.massivecraft.massivecore.collections.MassiveSet;
 
-public class ARSoundEffect extends ArgReaderAbstract<SoundEffect>
+public class ARSoundEffect extends ARAbstractException<SoundEffect>
 {
 	// -------------------------------------------- //
 	// INSTANCE & CONSTRUCT
@@ -19,19 +22,28 @@ public class ARSoundEffect extends ArgReaderAbstract<SoundEffect>
 	// -------------------------------------------- //
 	
 	@Override
-	public SoundEffect read(String arg, CommandSender sender) throws MassiveException
+	public SoundEffect valueOf(String arg, CommandSender sender) throws Exception
 	{
-		SoundEffect ret;
+		return SoundEffect.valueOf(arg);
+	}
 	
-		try
+	@Override
+	public Collection<String> getTabList(CommandSender sender, String arg)
 	{
-			ret = SoundEffect.valueOf(arg);
-		}
-		catch (Exception e)
+		Set<String> ret = new MassiveSet<String>();
+		
+		for (String str : ARSound.get().getTabList(sender, arg))
 		{
-			throw new MassiveException().addMsg("<b>%s", e.getMessage());
+			ret.add(str + "-");
 		}
+		
 		return ret;
 	}
 	
+	@Override
+	public boolean allowSpaceAfterTab()
+	{
+		return false;
+	}
+
 }

src/com/massivecraft/massivecore/cmd/arg/ARSoundEffects.java

@@ -1,53 +0,0 @@
-package com.massivecraft.massivecore.cmd.arg;
-
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.List;
-
-import org.bukkit.command.CommandSender;
-
-import com.massivecraft.massivecore.MassiveException;
-import com.massivecraft.massivecore.SoundEffect;
-
-/**
- * @deprecated use ARList
- */
-@Deprecated
-public class ARSoundEffects extends ArgReaderAbstract<List<SoundEffect>>
-{
-	// -------------------------------------------- //
-	// INSTANCE & CONSTRUCT
-	// -------------------------------------------- //
-	
-	private static ARSoundEffects i = new ARSoundEffects();
-	public static ARSoundEffects get() { return i; }
-	
-	// -------------------------------------------- //
-	// OVERRIDE
-	// -------------------------------------------- //
-	
-	@Override
-	public List<SoundEffect> read(String arg, CommandSender sender) throws MassiveException
-	{
-		List<SoundEffect> ret = new ArrayList<SoundEffect>();
-		List<SoundEffect> result = new ArrayList<SoundEffect>();
-		
-		arg = arg.trim();
-		List<String> soundStrings = Arrays.asList(arg.split("\\s+"));
-		
-		try
-		{
-			for (String soundString : soundStrings)
-			{
-				result.add(SoundEffect.valueOf(soundString));
-			}
-			ret = result;
-		}
-		catch (Exception e)
-		{
-			throw new MassiveException().addMsg("<b>%s", e.getMessage());
-		}
-		return ret;
-	}
-	
-}

src/com/massivecraft/massivecore/cmd/arg/ARString.java

@@ -1,8 +1,11 @@
 package com.massivecraft.massivecore.cmd.arg;
 
+import java.util.Collection;
+import java.util.Collections;
+
 import org.bukkit.command.CommandSender;
 
-public class ARString extends ArgReaderAbstract<String>
+public class ARString extends ARAbstract<String>
 {
 	// -------------------------------------------- //
 	// INSTANCE & CONSTRUCT
@@ -15,10 +18,22 @@ public class ARString extends ArgReaderAbstract<String>
 	// OVERRIDE
 	// -------------------------------------------- //
 
+	@Override
+	public String getTypeName()
+	{
+		return "text";
+	}
+	
 	@Override
 	public String read(String arg, CommandSender sender)
 	{
 		return arg;
 	}
 	
+	@Override
+	public Collection<String> getTabList(CommandSender sender, String arg)
+	{
+		return Collections.emptySet();
+	}
+
 }

src/com/massivecraft/massivecore/cmd/arg/ARUniverse.java

@@ -7,9 +7,10 @@ import org.bukkit.command.CommandSender;
 
 import com.massivecraft.massivecore.MassiveException;
 import com.massivecraft.massivecore.Multiverse;
+import com.massivecraft.massivecore.collections.MassiveSet;
 import com.massivecraft.massivecore.util.Txt;
 
-public class ARUniverse extends ArgReaderAbstract<String>
+public class ARUniverse extends ARAbstract<String>
 {
 	// -------------------------------------------- //
 	// INSTANCE & CONSTRUCT
@@ -25,7 +26,7 @@ public class ARUniverse extends ArgReaderAbstract<String>
 	// -------------------------------------------- //
 	
 	protected Multiverse multiverse;
-	public Multiverse multiverse() { return this.multiverse; }
+	public Multiverse getMultiverse() { return this.multiverse; }
 	
 	// -------------------------------------------- //
 	// OVERRIDE
@@ -34,28 +35,29 @@ public class ARUniverse extends ArgReaderAbstract<String>
 	@Override
 	public String read(String arg, CommandSender sender) throws MassiveException
 	{
-		String result = new String();
-		
 		if (multiverse.containsUniverse(arg))
 		{
-			result = arg;
+			return arg;
 		}
 		else
 		{
-			MassiveException exception = new MassiveException();
-			exception.addMsg("<b>No universe \"<h>%s<b>\" exists in multiverse <h>%s<b>.", arg, this.multiverse.getId());
-			
 			Collection<String> names = new ArrayList<String>(multiverse.getUniverses());
 			String format = Txt.parse("<h>%s");
 			String comma = Txt.parse("<i>, ");
 			String and = Txt.parse(" <i>or ");
 			String dot = Txt.parse("<i>.");
-			exception.addMsg("<i>Use %s", Txt.implodeCommaAndDot(names, format, comma, and, dot));
 			
-			throw exception;
+			throw new MassiveException()
+			.addMsg("<b>No universe \"<h>%s<b>\" exists in multiverse <h>%s<b>.", arg, this.multiverse.getId())
+			.addMsg("<i>Use %s", Txt.implodeCommaAndDot(names, format, comma, and, dot));
+		}
 	}
 	
-		return result;
+	@Override
+	public Collection<String> getTabList(CommandSender sender, String arg)
+	{
+		// MassiveSet is linked.
+		return new MassiveSet<String>(multiverse.getUniverses());
 	}
 
 }

src/com/massivecraft/massivecore/cmd/arg/ARWorld.java

@@ -1,12 +1,14 @@
 package com.massivecraft.massivecore.cmd.arg;
 
+import java.util.Collection;
+
 import org.bukkit.Bukkit;
 import org.bukkit.World;
 import org.bukkit.command.CommandSender;
 
 import com.massivecraft.massivecore.MassiveException;
 
-public class ARWorld extends ArgReaderAbstract<World>
+public class ARWorld extends ARAbstract<World>
 {
 	// -------------------------------------------- //
 	// INSTANCE & CONSTRUCT
@@ -24,9 +26,7 @@ public class ARWorld extends ArgReaderAbstract<World>
 	{
 		World ret;
 		
-		String inner = ARWorldId.get().read(arg, sender);
-		
-		String worldId = inner;
+		String worldId = ARWorldId.get().read(arg, sender);
 		
 		ret = Bukkit.getWorld(worldId);
 		
@@ -38,4 +38,10 @@ public class ARWorld extends ArgReaderAbstract<World>
 		return ret;
 	}
 	
+	@Override
+	public Collection<String> getTabList(CommandSender sender, String arg)
+	{
+		return ARWorldId.get().getTabList(sender, arg);
+	}
+
 }

src/com/massivecraft/massivecore/cmd/arg/ARWorldId.java

@@ -1,6 +1,7 @@
 package com.massivecraft.massivecore.cmd.arg;
 
 import java.util.ArrayList;
+import java.util.Collection;
 import java.util.List;
 
 import org.bukkit.command.CommandSender;
@@ -21,7 +22,7 @@ public class ARWorldId extends ARAbstractSelect<String>
 	// -------------------------------------------- //
 	
 	@Override
-	public String typename()
+	public String getTypeName()
 	{
 		return "world";
 	}
@@ -33,13 +34,15 @@ public class ARWorldId extends ARAbstractSelect<String>
 		
 		for (String worldId : visibleWorldIds)
 		{
-			if ( ! Mixin.canSeeWorld(sender, worldId)) continue;
+			// This was already done above in Mixin.getVisibleWorldIds(sender);
+			// if ( ! Mixin.canSeeWorld(sender, worldId)) continue;
 			if (arg.equalsIgnoreCase(worldId)) return worldId;
 		}
 		
 		for (String worldId : visibleWorldIds)
 		{
-			if ( ! Mixin.canSeeWorld(sender, worldId)) continue;
+			// This was already done above in Mixin.getVisibleWorldIds(sender);
+			// if ( ! Mixin.canSeeWorld(sender, worldId)) continue;
 			for (String worldAlias : Mixin.getWorldAliases(worldId))
 			{
 				if (arg.equalsIgnoreCase(worldAlias)) return worldId;
@@ -61,4 +64,10 @@ public class ARWorldId extends ARAbstractSelect<String>
 		return ret;
 	}
 
+	@Override
+	public Collection<String> getTabList(CommandSender sender, String arg)
+	{
+		return Mixin.getVisibleWorldIds(sender);
+	}
+	
 }

src/com/massivecraft/massivecore/cmd/arg/ARWorldType.java

@@ -1,6 +1,8 @@
 package com.massivecraft.massivecore.cmd.arg;
 
 import java.util.Collection;
+import java.util.Collections;
+import java.util.List;
 
 import org.bukkit.WorldType;
 import org.bukkit.command.CommandSender;
@@ -9,6 +11,12 @@ import com.massivecraft.massivecore.util.MUtil;
 
 public class ARWorldType extends ARAbstractSelect<WorldType>
 {
+	// -------------------------------------------- //
+	// CONSTANTS
+	// -------------------------------------------- //
+	
+	public static final List<String> ALT_NAMES = Collections.unmodifiableList(MUtil.list("normal", "flat", "1.1", "largebiomes"));
+	
 	// -------------------------------------------- //
 	// INSTANCE & CONSTRUCT
 	// -------------------------------------------- //
@@ -20,55 +28,64 @@ public class ARWorldType extends ARAbstractSelect<WorldType>
 	// OVERRIDE
 	// -------------------------------------------- //
 
-	@Override
-	public String typename()
-	{
-		return "world type";
-	}
-
 	@Override
 	public WorldType select(String arg, CommandSender sender)
 	{	
-		WorldType ret = null;
-		
-		// "DEFAULT_1_1" --> "11"
-		// "LARGE_BIOMES" --> "large"
-		// "Default" --> ""
-		arg = arg.toLowerCase();
-		arg = arg.replace("_", "");
-		arg = arg.replace(".", "");
-		arg = arg.replace("normal", "");
-		arg = arg.replace("default", "");
-		arg = arg.replace("biomes", "");
+		arg = getComparable(arg);
 		
 		if (arg.equals(""))
 		{
 			// "normal" or "default"
-			ret = WorldType.NORMAL;
+			return WorldType.NORMAL;
 		}
 		else if (arg.startsWith("flat"))
 		{
 			// "flat"
-			ret = WorldType.FLAT;
+			return WorldType.FLAT;
 		}
 		else if (arg.contains("11"))
 		{
 			// "VERSION_1_1"
-			ret = WorldType.VERSION_1_1;
+			return WorldType.VERSION_1_1;
 		}
 		else if (arg.contains("large"))
 		{
 			// "LARGE_BIOMES"
-			ret = WorldType.LARGE_BIOMES;
+			return WorldType.LARGE_BIOMES;
 		}
 		
-		return ret;
+		return null;
 	}
 
 	@Override
 	public Collection<String> altNames(CommandSender sender)
 	{
-		return MUtil.list("normal", "flat", "1.1", "largebiomes");
+		return ALT_NAMES;
+	}
+
+	@Override
+	public Collection<String> getTabList(CommandSender sender, String arg)
+	{
+		return this.altNames(sender);
+	}
+	
+	// -------------------------------------------- //
+	// UTIL
+	// -------------------------------------------- //
+	
+	public static String getComparable(String string)
+	{
+		// "DEFAULT_1_1" --> "11"
+		// "LARGE_BIOMES" --> "large"
+		// "Default" --> ""
+		string = string.toLowerCase();
+		string = string.replace("_", "");
+		string = string.replace(".", "");
+		string = string.replace("normal", "");
+		string = string.replace("default", "");
+		string = string.replace("biomes", "");
+		
+		return string;
 	}
 	
 }

src/com/massivecraft/massivecore/cmd/arg/ArgReader.java

@@ -1,13 +0,0 @@
-package com.massivecraft.massivecore.cmd.arg;
-
-import org.bukkit.command.CommandSender;
-
-import com.massivecraft.massivecore.MassiveException;
-
-public interface ArgReader<T>
-{
-	public T read(String arg, CommandSender sender) throws MassiveException;
-	public T read(CommandSender sender) throws MassiveException;
-	public T read(String arg) throws MassiveException;
-	public T readArg() throws MassiveException;
-}

src/com/massivecraft/massivecore/cmd/arg/ArgReaderAbstract.java

@@ -1,31 +0,0 @@
-package com.massivecraft.massivecore.cmd.arg;
-
-import org.bukkit.command.CommandSender;
-
-import com.massivecraft.massivecore.MassiveException;
-
-public abstract class ArgReaderAbstract<T> implements ArgReader<T>
-{
-	// -------------------------------------------- //
-	// OVERRIDE
-	// -------------------------------------------- //
-	
-	@Override
-	public T read(CommandSender sender) throws MassiveException
-	{
-		return this.read(null, sender);
-	}
-
-	@Override
-	public T read(String arg) throws MassiveException
-	{
-		return this.read(arg, null);
-	}
-
-	@Override
-	public T readArg() throws MassiveException
-	{
-		return this.read(null, null);
-	}
-	
-}

src/com/massivecraft/massivecore/util/Txt.java

@@ -1,8 +1,14 @@
 package com.massivecraft.massivecore.util;
 
-import java.util.*;
 import java.util.AbstractMap.SimpleEntry;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
 import java.util.Map.Entry;
+import java.util.Set;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
@@ -11,6 +17,9 @@ import org.bukkit.Material;
 import org.bukkit.command.CommandSender;
 import org.bukkit.entity.Player;
 
+import com.massivecraft.massivecore.Predictate;
+import com.massivecraft.massivecore.PredictateStartsWithIgnoreCase;
+
 public class Txt
 {
 	// -------------------------------------------- //
@@ -567,6 +576,38 @@ public class Txt
 		return ret;
 	}
 	
+	// -------------------------------------------- //
+	// FILTER
+	// -------------------------------------------- //
+	
+	public static <T> List<T> getFiltered(Collection<T> elements, Predictate<T> predictate)
+	{
+		List<T> ret = new ArrayList<T>();
+		
+		for (T element : elements)
+		{
+			if ( ! predictate.apply(element)) continue;
+			ret.add(element);
+		}
+		
+		return ret;
+	}
+	
+	public static <T> List<T> getFiltered(T[] elements, Predictate<T> predictate)
+	{
+		return getFiltered(Arrays.asList(elements), predictate);
+	}
+	
+	public static List<String> getStartsWithIgnoreCase(Collection<String> elements, String prefix)
+	{
+		return getFiltered(elements, PredictateStartsWithIgnoreCase.get(prefix));
+	}
+	
+	public static List<String> getStartsWithIgnoreCase(String[] elements, String prefix)
+	{
+		return getStartsWithIgnoreCase(Arrays.asList(elements), prefix);
+	}
+	
 	// -------------------------------------------- //
 	// Tokenization
 	// -------------------------------------------- //