Remove some unused method on Varargs

src/main/java/org/squiddev/cobalt/LuaValue.java

@@ -156,7 +156,6 @@ public final LuaString luaTypeName() {
 	 * @see Constants#NIL
 	 * @see Constants#NONE
 	 * @see #optValue(LuaValue)
-	 * @see Varargs#isNoneOrNil(int)
 	 * @see Constants#TNIL
 	 */
 	public final boolean isNil() {
@@ -499,7 +498,6 @@ public final LuaThread optThread(LuaThread defval) throws LuaError {
 	 * @see Constants#NIL
 	 * @see Constants#NONE
 	 * @see #isNil()
-	 * @see Varargs#isNoneOrNil(int)
 	 * @see Constants#TNIL
 	 */
 	public final LuaValue optValue(LuaValue defval) {
@@ -700,6 +698,7 @@ public int count() {
 	}
 
 	@Override
+	@Deprecated
 	public LuaValue first() {
 		return this;
 	}

src/main/java/org/squiddev/cobalt/Varargs.java

@@ -41,7 +41,6 @@
  *
  * @see ValueFactory#varargsOf(LuaValue[])
  * @see ValueFactory#varargsOf(LuaValue, Varargs)
- * @see ValueFactory#varargsOf(LuaValue[], Varargs)
  * @see ValueFactory#varargsOf(LuaValue, LuaValue, Varargs)
  * @see ValueFactory#varargsOfCopy(LuaValue[], int, int)
  * @see ValueFactory#varargsOfCopy(LuaValue[], int, int, Varargs)
@@ -79,42 +78,6 @@ public abstract class Varargs {
 
 	public abstract void fill(LuaValue[] array, int offset);
 
-	// -----------------------------------------------------------------------
-	// utilities to get specific arguments and type-check them.
-	// -----------------------------------------------------------------------
-
-	/**
-	 * Gets the type of argument {@code i}
-	 *
-	 * @param i the index of the argument to convert, 1 is the first argument
-	 * @return int value corresponding to one of the LuaValue integer type values
-	 * @see LuaValue#type()
-	 */
-	public int type(int i) {
-		return arg(i).type();
-	}
-
-	/**
-	 * Tests if argument i is nil.
-	 *
-	 * @param i the index of the argument to test, 1 is the first argument
-	 * @return true if the argument is nil or does not exist, false otherwise
-	 * @see Constants#TNIL
-	 */
-	public boolean isNil(int i) {
-		return arg(i).isNil();
-	}
-
-	/**
-	 * Tests if a value exists at argument i.
-	 *
-	 * @param i the index of the argument to test, 1 is the first argument
-	 * @return true if the argument exists, false otherwise
-	 */
-	public boolean exists(int i) {
-		return i > 0 && i <= count();
-	}
-
 	/**
 	 * Return argument i as a LuaValue if it exists, or throw an error.
 	 *
@@ -130,30 +93,6 @@ public LuaValue checkValue(int i) throws LuaError {
 		}
 	}
 
-	/**
-	 * Throw an error if {@code test} fails
-	 *
-	 * @param test user	 supplied assertion to test against
-	 * @param i    the index to report in any error message
-	 * @param msg  the error message to use when the test fails
-	 * @throws LuaError if the the value of {@code test} is {@code false}
-	 */
-	public static void argCheck(boolean test, int i, String msg) throws LuaError {
-		if (!test) {
-			throw ErrorFactory.argError(i, msg);
-		}
-	}
-
-	/**
-	 * Return true if there is no argument or nil at argument i.
-	 *
-	 * @param i the index of the argument to test, 1 is the first argument
-	 * @return true if argument i contains either no argument or nil
-	 */
-	public boolean isNoneOrNil(int i) {
-		return i > count() || arg(i).isNil();
-	}
-
 	/**
 	 * Convert the list of varargs values to a human readable java String.
 	 *

src/main/java/org/squiddev/cobalt/lib/BaseLib.java

@@ -110,10 +110,10 @@ private static LuaValue getfenvobj(LuaState state, LuaValue arg, boolean optiona
 		if (arg instanceof LuaFunction) return arg;
 
 		int level = optional ? arg.optInteger(1) : arg.checkInteger();
-		Varargs.argCheck(level >= 0, 1, "level must be non-negative");
+		if (level < 0) throw ErrorFactory.argError(1, "level must be non-negative");
 		if (level == 0) return state.getCurrentThread();
 		LuaValue f = LuaThread.getCallstackFunction(state, level);
-		Varargs.argCheck(f != null, 1, "invalid level");
+		if (f == null) throw ErrorFactory.argError(1, "invalid level");
 		return f;
 	}
 

src/main/java/org/squiddev/cobalt/lib/TableLib.java

@@ -26,6 +26,7 @@
 
 import cc.tweaked.cobalt.internal.unwind.AutoUnwind;
 import cc.tweaked.cobalt.internal.unwind.SuspendedAction;
+import org.checkerframework.checker.nullness.qual.Nullable;
 import org.squiddev.cobalt.*;
 import org.squiddev.cobalt.debug.DebugFrame;
 import org.squiddev.cobalt.function.Dispatch;
@@ -275,14 +276,14 @@ private static Varargs sort(LuaState state, DebugFrame di, Varargs args) throws
 			return SuspendedAction.run(di, () -> {
 				int n = OperationHelper.intLength(state, table);
 
-				LuaValue compare = args.isNoneOrNil(2) ? NIL : args.arg(2).checkFunction();
+				LuaFunction compare = args.arg(2).optFunction(null);
 				if (n > 1) heapSort(state, table, n, compare);
 				return NONE;
 			});
 		}
 
 		@AutoUnwind
-		private static void heapSort(LuaState state, LuaValue table, int count, LuaValue compare) throws LuaError, UnwindThrowable {
+		private static void heapSort(LuaState state, LuaValue table, int count, @Nullable LuaFunction compare) throws LuaError, UnwindThrowable {
 			for (int start = count / 2 - 1; start >= 0; start--) {
 				siftDown(state, table, start, count - 1, compare);
 			}
@@ -298,7 +299,7 @@ private static void heapSort(LuaState state, LuaValue table, int count, LuaValue
 		}
 
 		@AutoUnwind
-		private static void siftDown(LuaState state, LuaValue table, int start, int end, LuaValue compare) throws LuaError, UnwindThrowable {
+		private static void siftDown(LuaState state, LuaValue table, int start, int end, @Nullable LuaFunction compare) throws LuaError, UnwindThrowable {
 			LuaValue rootValue = OperationHelper.getTable(state, table, start + 1);
 
 			for (int root = start; root * 2 + 1 <= end; ) {
@@ -325,8 +326,8 @@ private static void siftDown(LuaState state, LuaValue table, int start, int end,
 		}
 
 		@AutoUnwind
-		private static boolean compare(LuaState state, LuaValue compare, LuaValue a, LuaValue b) throws LuaError, UnwindThrowable {
-			return compare.isNil()
+		private static boolean compare(LuaState state, @Nullable LuaFunction compare, LuaValue a, LuaValue b) throws LuaError, UnwindThrowable {
+			return compare == null
 				? OperationHelper.lt(state, a, b)
 				: Dispatch.call(state, compare, a, b).toBoolean();
 		}

src/main/java/org/squiddev/cobalt/lib/system/SystemBaseLib.java

@@ -62,17 +62,17 @@ private static LuaValue collectgarbage(LuaState state, LuaValue arg1, LuaValue a
 
 	private Varargs loadfile(LuaState state, Varargs args) throws LuaError {
 		// loadfile( [filename] ) -> chunk | nil, msg
-		return args.isNil(1) ?
+		return args.first().isNil() ?
 			BaseLib.loadStream(state, in, STDIN_STR) :
 			SystemBaseLib.loadFile(state, resources, args.arg(1).checkString());
 	}
 
 	private Varargs dofile(LuaState state, Varargs args) throws LuaError, UnwindThrowable {
 		// dofile( filename ) -> result1, ...
-		Varargs v = args.isNil(1) ?
+		Varargs v = args.first().isNil() ?
 			BaseLib.loadStream(state, in, STDIN_STR) :
 			SystemBaseLib.loadFile(state, resources, args.arg(1).checkString());
-		if (v.isNil(1)) {
+		if (v.first().isNil()) {
 			throw new LuaError(v.arg(2).toString());
 		} else {
 			return Dispatch.invoke(state, v.first(), Constants.NONE);