From a2119cb6914d62e626fcc40684ef900d7fa90d86 Mon Sep 17 00:00:00 2001
From: Max Brunsfeld <maxbrunsfeld@gmail.com>
Date: Mon, 12 Jun 2023 11:50:44 -0700
Subject: [PATCH] Add APIs for retrieving tree cursor's depth and descendant
 index

---
 lib/binding_rust/bindings.rs  |  7 +++++-
 lib/binding_rust/lib.rs       | 15 +++++++++++++
 lib/binding_web/README.md     |  2 +-
 lib/include/tree_sitter/api.h |  8 ++++++-
 lib/src/tree_cursor.c         | 42 ++++++++++++++---------------------
 script/generate-bindings      |  1 +
 6 files changed, 47 insertions(+), 28 deletions(-)

diff --git a/lib/binding_rust/bindings.rs b/lib/binding_rust/bindings.rs
index 1d3b6a30..b584a509 100644
--- a/lib/binding_rust/bindings.rs
+++ b/lib/binding_rust/bindings.rs
@@ -615,7 +615,12 @@ extern "C" {
 extern "C" {
     #[doc = " Get the index of the cursor's current node out of all of the"]
     #[doc = " descendants of the original node that the cursor was constructed with."]
-    pub fn ts_tree_cursor_descendant_index(arg1: *mut TSTreeCursor) -> u32;
+    pub fn ts_tree_cursor_current_descendant_index(arg1: *const TSTreeCursor) -> u32;
+}
+extern "C" {
+    #[doc = " Get the depth of the cursor's current node relative to the original"]
+    #[doc = " node that the cursor was constructed with."]
+    pub fn ts_tree_cursor_current_depth(arg1: *const TSTreeCursor) -> u32;
 }
 extern "C" {
     #[doc = " Move the cursor to the first child of its current node that extends beyond"]
diff --git a/lib/binding_rust/lib.rs b/lib/binding_rust/lib.rs
index b717a161..b6255085 100644
--- a/lib/binding_rust/lib.rs
+++ b/lib/binding_rust/lib.rs
@@ -1266,6 +1266,21 @@ impl<'a> TreeCursor<'a> {
         }
     }
 
+    /// Get the numerical field id of this tree cursor's current node.
+    ///
+    /// See also [field_name](TreeCursor::field_name).
+    #[doc(alias = "ts_tree_cursor_current_depth")]
+    pub fn depth(&self) -> u32 {
+        unsafe { ffi::ts_tree_cursor_current_depth(&self.0) }
+    }
+
+    /// Get the index of the cursor's current node out of all of the
+    /// descendants of the original node that the cursor was constructed with
+    #[doc(alias = "ts_tree_cursor_current_descendant_index")]
+    pub fn descendant_index(&self) -> usize {
+        unsafe { ffi::ts_tree_cursor_current_descendant_index(&self.0) as usize }
+    }
+
     /// Move this cursor to the first child of its current node.
     ///
     /// This returns `true` if the cursor successfully moved, and returns `false`
diff --git a/lib/binding_web/README.md b/lib/binding_web/README.md
index b0ffc3ef..bfddd9ef 100644
--- a/lib/binding_web/README.md
+++ b/lib/binding_web/README.md
@@ -12,7 +12,7 @@ WebAssembly bindings to the [Tree-sitter](https://github.com/tree-sitter/tree-si
 You can download the `tree-sitter.js` and `tree-sitter.wasm` files from [the latest GitHub release](https://github.com/tree-sitter/tree-sitter/releases/latest) and load them using a standalone script:
 
 ```html
-<script src="/the/path/to/tree-sitter.js"/>
+<script src="/the/path/to/tree-sitter.js"></script>
 
 <script>
   const Parser = window.TreeSitter;
diff --git a/lib/include/tree_sitter/api.h b/lib/include/tree_sitter/api.h
index 04aafb84..e455e81d 100644
--- a/lib/include/tree_sitter/api.h
+++ b/lib/include/tree_sitter/api.h
@@ -689,7 +689,13 @@ void ts_tree_cursor_goto_descendant(TSTreeCursor *, uint32_t);
  * Get the index of the cursor's current node out of all of the
  * descendants of the original node that the cursor was constructed with.
  */
-uint32_t ts_tree_cursor_descendant_index(TSTreeCursor *);
+uint32_t ts_tree_cursor_current_descendant_index(const TSTreeCursor *);
+
+/**
+ * Get the depth of the cursor's current node relative to the original
+ * node that the cursor was constructed with.
+ */
+uint32_t ts_tree_cursor_current_depth(const TSTreeCursor *);
 
 /**
  * Move the cursor to the first child of its current node that extends beyond
diff --git a/lib/src/tree_cursor.c b/lib/src/tree_cursor.c
index 18ee023d..5c102fcc 100644
--- a/lib/src/tree_cursor.c
+++ b/lib/src/tree_cursor.c
@@ -261,22 +261,10 @@ bool ts_tree_cursor_goto_next_sibling(TSTreeCursor *self) {
 bool ts_tree_cursor_goto_parent(TSTreeCursor *_self) {
   TreeCursor *self = (TreeCursor *)_self;
   for (unsigned i = self->stack.size - 2; i + 1 > 0; i--) {
-    TreeCursorEntry *entry = &self->stack.contents[i];
-    if (ts_subtree_visible(*entry->subtree)) {
+    if (ts_tree_cursor_is_entry_visible(self, i)) {
       self->stack.size = i + 1;
       return true;
     }
-    if (i > 0 && !ts_subtree_extra(*entry->subtree)) {
-      TreeCursorEntry *parent_entry = &self->stack.contents[i - 1];
-      if (ts_language_alias_at(
-        self->tree->language,
-        parent_entry->subtree->ptr->production_id,
-        entry->structural_child_index
-      )) {
-        self->stack.size = i + 1;
-        return true;
-      }
-    }
   }
   return false;
 }
@@ -331,7 +319,7 @@ void ts_tree_cursor_goto_descendant(
   } while (did_descend);
 }
 
-uint32_t ts_tree_cursor_descendant_index(TSTreeCursor *_self) {
+uint32_t ts_tree_cursor_current_descendant_index(const TSTreeCursor *_self) {
   const TreeCursor *self = (const TreeCursor *)_self;
   TreeCursorEntry *last_entry = array_back(&self->stack);
   return last_entry->descendant_index;
@@ -479,6 +467,17 @@ void ts_tree_cursor_current_status(
   }
 }
 
+uint32_t ts_tree_cursor_current_depth(const TSTreeCursor *_self) {
+  const TreeCursor *self = (const TreeCursor *)_self;
+  uint32_t depth = 0;
+  for (unsigned i = 1; i < self->stack.size; i++) {
+    if (ts_tree_cursor_is_entry_visible(self, i)) {
+      depth++;
+    }
+  }
+  return depth;
+}
+
 TSNode ts_tree_cursor_parent_node(const TSTreeCursor *_self) {
   const TreeCursor *self = (const TreeCursor *)_self;
   for (int i = (int)self->stack.size - 2; i >= 0; i--) {
@@ -515,17 +514,10 @@ TSFieldId ts_tree_cursor_current_field_id(const TSTreeCursor *_self) {
     TreeCursorEntry *parent_entry = &self->stack.contents[i - 1];
 
     // Stop walking up when another visible node is found.
-    if (i != self->stack.size - 1) {
-      if (ts_subtree_visible(*entry->subtree)) break;
-      if (
-        !ts_subtree_extra(*entry->subtree) &&
-        ts_language_alias_at(
-          self->tree->language,
-          parent_entry->subtree->ptr->production_id,
-          entry->structural_child_index
-        )
-      ) break;
-    }
+    if (
+      i != self->stack.size - 1 &&
+      ts_tree_cursor_is_entry_visible(self, i)
+    ) break;
 
     if (ts_subtree_extra(*entry->subtree)) break;
 
diff --git a/script/generate-bindings b/script/generate-bindings
index 25499c0e..8757aaeb 100755
--- a/script/generate-bindings
+++ b/script/generate-bindings
@@ -4,6 +4,7 @@ output_path=lib/binding_rust/bindings.rs
 header_path='lib/include/tree_sitter/api.h'
 
 bindgen                                        \
+  --size_t-is-usize                            \
   --no-layout-tests                            \
   --allowlist-type '^TS.*'                     \
   --allowlist-function '^ts_.*'                \