Updates from PR feedback and added tests

gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/language/grammar/ArgumentVisitor.java

@@ -20,11 +20,9 @@
 
 import org.apache.tinkerpop.gremlin.process.traversal.step.GType;
 import org.apache.tinkerpop.gremlin.process.traversal.step.GValue;
-import org.apache.tinkerpop.gremlin.structure.Vertex;
 import org.apache.tinkerpop.gremlin.util.iterator.IteratorUtils;
 
 import java.lang.reflect.Array;
-import java.time.OffsetDateTime;
 import java.util.Map;
 import java.util.Objects;
 

gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/process/traversal/P.java

@@ -77,15 +77,11 @@ public void setValue(final V value) {
 
     @Override
     public boolean test(final V testValue) {
-        if (this.value instanceof GValue) {
-            return this.biPredicate.test(testValue, ((GValue<V>) this.value).get());
+        // this might be a bunch of GValue that need to be resolved. zomg
+        if (this.value instanceof List) {
+            return this.biPredicate.test(testValue, (V) ((List) this.value).stream().map(GValue::valueOf).collect(Collectors.toList()));
         } else {
-            // this might be a bunch of GValue that need to be resolved. zomg
-            if (this.value instanceof List) {
-                return this.biPredicate.test(testValue, (V) ((List) this.value).stream().map(GValue::valueOf).collect(Collectors.toList()));
-            } else {
-                return this.biPredicate.test(testValue, this.value);
-            }
+            return this.biPredicate.test(testValue, (V) GValue.valueOf(this.value));
         }
     }
 

gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/process/traversal/step/GValue.java

@@ -117,6 +117,11 @@ public int hashCode() {
         return Objects.hash(name, type, value);
     }
 
+    @Override
+    public GValue<V> clone() {
+        return new GValue<>(this.name, this.type, this.value);
+    }
+
     /**
      * Create a new {@code Var} from a particular value but without the specified name. If the argument provide is
      * already a {@code GValue} then it is returned as-is.

gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/process/traversal/step/util/Parameters.java

@@ -189,10 +189,8 @@ public <S> Object[] getKeyValues(final Traverser.Admin<S> traverser, final Objec
     private static <S> Object resolve(final Object object, final Traverser.Admin<S> traverser) {
         if (object instanceof Traversal.Admin) {
             return TraversalUtil.apply(traverser, (Traversal.Admin<S, ?>) object);
-        } else if (object instanceof GValue) {
-            return ((GValue) object).get();
         } else {
-            return object;
+            return GValue.valueOf(object);
         }
     }
 

gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/process/traversal/strategy/decoration/SideEffectStrategy.java

@@ -64,8 +64,10 @@ public static <A> void addSideEffect(final TraversalStrategies traversalStrategi
 
         // don't want the GValue to leak beyond strategy application or else the Supplier will start producing it
         // during execution
-        final ConstantSupplier initialValue = value instanceof GValue ? new ConstantSupplier<>(((GValue) value).get()) : new ConstantSupplier<>(value);
-        strategy.sideEffects.add(new Triplet<>(key, value instanceof Supplier ? (Supplier) value : initialValue, reducer));
+        strategy.sideEffects.add(new Triplet<>(key, () -> {
+            Object initialValue = value instanceof Supplier ? ((Supplier) value).get() : value;
+            return GValue.valueOf(initialValue);
+        }, reducer));
     }
 
     public boolean contains(final String sideEffectKey) {

gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/util/CollectionUtil.java

@@ -102,11 +102,7 @@ public static <K,V> ConcurrentHashMap<K,V> clone(final ConcurrentHashMap<K,V> ma
      * element as a new array with just that item in it.
      */
     public static <T> T[] addFirst(final T[] array, final T element, final Class<T> clazz) {
-        if (null == array && null == element) {
-            final T[] singleElementArray = (T[]) Array.newInstance(clazz, 1);
-            singleElementArray[0] = null;
-            return singleElementArray;
-        } else if (null == array) {
+        if (null == array) {
             final T[] singleElementArray = (T[]) Array.newInstance(clazz, 1);
             singleElementArray[0] = element;
             return singleElementArray;

gremlin-core/src/test/java/org/apache/tinkerpop/gremlin/process/traversal/step/GValueTest.java

@@ -638,4 +638,28 @@ public void numberOfShouldThrowBecauseNullIntegerGType() {
     public void numberOfShouldThrowBecauseNullObject() {
         GValue.numberOf(null);
     }
+
+    @Test
+    public void numberOfShouldAcceptAllNumericTypeLiterals() {
+        assertEquals((byte) 123, GValue.numberOf((byte) 123));
+        assertEquals((short) 123, GValue.numberOf((short) 123));
+        assertEquals(123, GValue.numberOf(123));
+        assertEquals(123l, GValue.numberOf(123l));
+        assertEquals(123.45f, GValue.numberOf(123.45f));
+        assertEquals(123.45, GValue.numberOf(123.45));
+        assertEquals(BigInteger.ONE, GValue.numberOf(BigInteger.ONE));
+        assertEquals(BigDecimal.ONE, GValue.numberOf(BigDecimal.ONE));
+    }
+
+    @Test
+    public void numberOfShouldAcceptAllNumericTypeGValues() {
+        assertEquals((byte) 123, GValue.numberOf(GValue.of((byte) 123)));
+        assertEquals((short) 123, GValue.numberOf((GValue.of((short) 123))));
+        assertEquals(123, GValue.numberOf((GValue.of(123))));
+        assertEquals(123l, GValue.numberOf((GValue.of(123l))));
+        assertEquals(123.45f, GValue.numberOf((GValue.of(123.45f))));
+        assertEquals(123.45, GValue.numberOf((GValue.of(123.45))));
+        assertEquals(BigInteger.ONE, GValue.numberOf((GValue.of(BigInteger.ONE))));
+        assertEquals(BigDecimal.ONE, GValue.numberOf((GValue.of(BigDecimal.ONE))));
+    }
 }