added back cached node in TreeCursor

Author: Emmeral

src/main/java/io/github/treesitter/jtreesitter/TreeCursor.java

@@ -15,6 +15,7 @@ public final class TreeCursor implements AutoCloseable, Cloneable {
     private final MemorySegment self;
     private final Arena arena;
     private final Tree tree;
+    private @Nullable Node node;
 
     TreeCursor(Node node, Tree tree) {
         arena = Arena.ofShared();
@@ -33,6 +34,7 @@ private TreeCursor(TreeCursor cursor) {
         arena = Arena.ofShared();
         self = ts_tree_cursor_copy(arena, cursor.self);
         tree = cursor.tree.clone();
+        node = cursor.node;
     }
 
     /**
@@ -41,9 +43,14 @@ private TreeCursor(TreeCursor cursor) {
      * @return the current node
      */
     public Node getCurrentNode() {
-        return getCurrentNode(arena);
+        if (this.node == null) {
+            var node = ts_tree_cursor_current_node(arena, self);
+            this.node = new Node(node, tree);
+        }
+        return this.node;
     }
 
+
     /**
      * Get the current node of the cursor. Its native memory will be managed by the given allocator.
      * @param allocator the allocator to use for managing the native memory of the node
@@ -97,7 +104,9 @@ public Node getCurrentNode(SegmentAllocator allocator) {
      *         {@code false} if there were no children.
      */
     public boolean gotoFirstChild() {
-        return ts_tree_cursor_goto_first_child(self);
+        var result = ts_tree_cursor_goto_first_child(self);
+        if (result) node = null;
+        return result;
     }
 
     /**
@@ -107,7 +116,9 @@ public boolean gotoFirstChild() {
      *         {@code false} if there were no children.
      */
     public boolean gotoLastChild() {
-        return ts_tree_cursor_goto_last_child(self);
+        var result = ts_tree_cursor_goto_last_child(self);
+        if (result) node = null;
+        return result;
     }
 
     /**
@@ -117,7 +128,9 @@ public boolean gotoLastChild() {
      *         {@code false} if there was no parent node.
      */
     public boolean gotoParent() {
-        return ts_tree_cursor_goto_parent(self);
+        var result = ts_tree_cursor_goto_parent(self);
+        if (result) node = null;
+        return result;
     }
 
     /**
@@ -127,7 +140,9 @@ public boolean gotoParent() {
      *         {@code false} if there was no next sibling node.
      */
     public boolean gotoNextSibling() {
-        return ts_tree_cursor_goto_next_sibling(self);
+        var result = ts_tree_cursor_goto_next_sibling(self);
+        if (result) node = null;
+        return result;
     }
 
     /**
@@ -137,7 +152,9 @@ public boolean gotoNextSibling() {
      *         {@code false} if there was no previous sibling node.
      */
     public boolean gotoPreviousSibling() {
-        return ts_tree_cursor_goto_previous_sibling(self);
+        var result = ts_tree_cursor_goto_previous_sibling(self);
+        if (result) node = null;
+        return result;
     }
 
     /**
@@ -148,7 +165,7 @@ public boolean gotoPreviousSibling() {
      */
     public void gotoDescendant(@Unsigned int index) {
         ts_tree_cursor_goto_descendant(self, index);
-
+        node = null;
     }
 
     /**
@@ -160,6 +177,7 @@ public void gotoDescendant(@Unsigned int index) {
     public @Unsigned OptionalInt gotoFirstChildForByte(@Unsigned int offset) {
         var index = ts_tree_cursor_goto_first_child_for_byte(self, offset);
         if (index == -1L) return OptionalInt.empty();
+        node = null;
         return OptionalInt.of((int) index);
     }
 
@@ -174,6 +192,7 @@ public void gotoDescendant(@Unsigned int index) {
             var goal = point.into(arena);
             var index = ts_tree_cursor_goto_first_child_for_point(self, goal);
             if (index == -1L) return OptionalInt.empty();
+            node = null;
             return OptionalInt.of((int) index);
         }
     }
@@ -182,12 +201,15 @@ public void gotoDescendant(@Unsigned int index) {
     public void reset(Node node) {
         try (var arena = Arena.ofConfined()) {
             ts_tree_cursor_reset(self, node.copy(arena));
+        } finally {
+            this.node = null;
         }
     }
 
     /** Reset the cursor to start at the same position as another cursor. */
     public void reset(TreeCursor cursor) {
         ts_tree_cursor_reset_to(self, cursor.self);
+        this.node = null;
     }
 
     /** Create a shallow copy of the tree cursor. */