Add getParent method to NBTElement interface

Author: Glavo

src/main/java/org/glavo/nbt/NBTElement.java

@@ -18,6 +18,9 @@
 import org.glavo.nbt.chunk.Chunk;
 import org.glavo.nbt.chunk.ChunkRegion;
 import org.glavo.nbt.tag.Tag;
+import org.jetbrains.annotations.Nullable;
 
 public sealed interface NBTElement permits ChunkRegion, Chunk, Tag, NBTParent {
+    /// Returns the parent of this element, or `null` if this element is not a child of any parent.
+    @Nullable NBTParent<?> getParent();
 }

src/main/java/org/glavo/nbt/chunk/Chunk.java

@@ -43,6 +43,13 @@ public Chunk(@Nullable CompoundTag rootTag) {
         return region;
     }
 
+    /// Return the region of this chunk, or `null` if this chunk is not in any region.
+    @Override
+    @Contract(pure = true)
+    public @Nullable ChunkRegion getParent() {
+        return getRegion();
+    }
+
     void setRegion(@Nullable ChunkRegion region, int localIndex) {
         this.region = region;
         this.localIndex = localIndex;

src/main/java/org/glavo/nbt/chunk/ChunkRegion.java

@@ -117,6 +117,13 @@ public static ChunkRegion readRegion(Path file) throws IOException {
     public ChunkRegion() {
     }
 
+    /// Always returns `null`. A chunk region is the root of the NBT tree, and it has no parent.
+    @Override
+    @Contract(value = "-> null", pure = true)
+    public @Nullable NBTParent<ChunkRegion> getParent() {
+        return null;
+    }
+
     @Contract(pure = true)
     public @Nullable Chunk getChunk(int localIndex) {
         Objects.checkIndex(localIndex, ChunkUtils.CHUNKS_PRE_REGION);

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

@@ -121,6 +121,7 @@ public int getIndex() {
     }
 
     /// If the tag is a child of a [parent][NBTParent], returns the parent; otherwise, returns `null`.
+    @Override
     public @Nullable NBTParent<? extends Tag> getParent() {
         return parent;
     }