Add generic type parameters to ArrayTag and ParentTag

Author: Glavo

src/main/java/org/glavo/nbt/tag/ArrayTag.java

@@ -16,7 +16,7 @@
 package org.glavo.nbt.tag;
 
 /// An abstract tag that contains an ordered list of values.
-public sealed abstract class ArrayTag extends Tag
+public sealed abstract class ArrayTag<E extends Number> extends Tag implements Iterable<E>
         permits ByteArrayTag, IntArrayTag, LongArrayTag {
 
     protected ArrayTag(String name) {

src/main/java/org/glavo/nbt/tag/ByteArrayTag.java

@@ -19,9 +19,11 @@
 
 import java.io.IOException;
 import java.util.Arrays;
+import java.util.Iterator;
+import java.util.NoSuchElementException;
 
 /// An ordered list of 8-bit integers.
-public final class ByteArrayTag extends ArrayTag {
+public final class ByteArrayTag extends ArrayTag<Byte> {
     private static final byte[] EMPTY = new byte[0];
 
     byte[] value;
@@ -74,6 +76,27 @@ public int size() {
         return value.length;
     }
 
+    @Override
+    public Iterator<Byte> iterator() {
+        final byte[] array = this.value;
+        return new Iterator<>() {
+            private int cursor;
+
+            @Override
+            public boolean hasNext() {
+                return cursor < array.length;
+            }
+
+            @Override
+            public Byte next() {
+                if (cursor >= array.length) {
+                    throw new NoSuchElementException();
+                }
+                return array[cursor++];
+            }
+        };
+    }
+
     @Override
     protected void readContent(NBTReader reader) throws IOException {
         value = reader.readByteArray();

src/main/java/org/glavo/nbt/tag/IntArrayTag.java

@@ -16,13 +16,14 @@
 package org.glavo.nbt.tag;
 
 import org.glavo.nbt.internal.input.NBTReader;
+import org.jetbrains.annotations.NotNull;
 
 import java.io.IOException;
-import java.util.Arrays;
+import java.util.*;
 import java.util.stream.IntStream;
 
 /// An ordered list of 32-bit integers.
-public final class IntArrayTag extends ArrayTag {
+public final class IntArrayTag extends ArrayTag<Integer> {
     private static final int[] EMPTY = new int[0];
 
     int[] value;
@@ -75,6 +76,27 @@ public int size() {
         return value.length;
     }
 
+    @Override
+    public PrimitiveIterator.OfInt iterator() {
+        final int[] array = this.value;
+        return new PrimitiveIterator.OfInt() {
+            private int cursor;
+
+            @Override
+            public boolean hasNext() {
+                return cursor < array.length;
+            }
+
+            @Override
+            public int nextInt() {
+                if (cursor >= array.length) {
+                    throw new NoSuchElementException();
+                }
+                return array[cursor++];
+            }
+        };
+    }
+
     /// Returns a sequential [IntStream] with this value as its source.
     public IntStream stream() {
         return Arrays.stream(value);

src/main/java/org/glavo/nbt/tag/LongArrayTag.java

@@ -19,10 +19,12 @@
 
 import java.io.IOException;
 import java.util.Arrays;
+import java.util.NoSuchElementException;
+import java.util.PrimitiveIterator;
 import java.util.stream.LongStream;
 
 /// An ordered list of 64-bit integers.
-public final class LongArrayTag extends ArrayTag {
+public final class LongArrayTag extends ArrayTag<Long> {
     private static final long[] EMPTY = new long[0];
 
     long[] value;
@@ -75,6 +77,27 @@ public int size() {
         return value.length;
     }
 
+    @Override
+    public PrimitiveIterator.OfLong iterator() {
+        final long[] array = this.value;
+        return new PrimitiveIterator.OfLong() {
+            private int cursor;
+
+            @Override
+            public boolean hasNext() {
+                return cursor < array.length;
+            }
+
+            @Override
+            public long nextLong() {
+                if (cursor >= array.length) {
+                    throw new NoSuchElementException();
+                }
+                return array[cursor++];
+            }
+        };
+    }
+
     /// Returns a sequential [LongStream] with this value as its source.
     public LongStream stream() {
         return Arrays.stream(value);
@@ -94,6 +117,7 @@ protected int contentHashCode() {
     protected boolean contentEquals(Tag other) {
         return other instanceof LongArrayTag that && Arrays.equals(value, that.value);
     }
+
     @Override
     protected void contentToString(StringBuilder builder) {
         if (value.length > 0) {

src/main/java/org/glavo/nbt/tag/ParentTag.java

@@ -20,11 +20,11 @@
 import java.util.List;
 
 /// An abstract tag that contains other tags.
-public sealed abstract class ParentTag<T extends Tag> extends Tag
-        implements Iterable<T>
+public sealed abstract class ParentTag<E extends Tag> extends Tag
+        implements Iterable<E>
         permits CompoundTag, ListTag {
 
-    final List<T> subTags = new ArrayList<>();
+    final List<E> subTags = new ArrayList<>();
 
     protected ParentTag(String name) {
         super(name);
@@ -61,7 +61,7 @@ public final int size() {
     /// Returns the subtag at the given index.
     ///
     /// @throws IndexOutOfBoundsException if the index is out of bounds.
-    public final T get(int index) throws IndexOutOfBoundsException {
+    public final E get(int index) throws IndexOutOfBoundsException {
         return subTags.get(index);
     }
 
@@ -70,7 +70,7 @@ public final T get(int index) throws IndexOutOfBoundsException {
     /// If the `tag` is already a child of this tag, does nothing.
     ///
     /// If the `tag` is already a child of another tag, removes it from old parent and adds it to this tag.
-    public abstract void add(T tag) throws IllegalArgumentException;
+    public abstract void add(E tag) throws IllegalArgumentException;
 
     /// Removes the `tag` from this tag.
     ///
@@ -80,8 +80,8 @@ public final T get(int index) throws IndexOutOfBoundsException {
     // Iterable implementation
 
     @Override
-    public final Iterator<T> iterator() {
-        Iterator<T> iterator = subTags.iterator();
+    public final Iterator<E> iterator() {
+        Iterator<E> iterator = subTags.iterator();
 
         // Prevent calling Iterator#remove()
         return new Iterator<>() {
@@ -91,7 +91,7 @@ public boolean hasNext() {
             }
 
             @Override
-            public T next() {
+            public E next() {
                 return iterator.next();
             }
         };

src/main/java/org/glavo/nbt/tag/Tag.java

@@ -174,7 +174,7 @@ protected void toString(StringBuilder builder) {
             builder.append(')');
         }
 
-        if (this instanceof ArrayTag || this instanceof ParentTag<?>) {
+        if (this instanceof ArrayTag<?> || this instanceof ParentTag<?>) {
             this.contentToString(builder);
         } else {
             builder.append('[');