Equal now recognizes tree-sitter nodes (bug#60659)

Now equal uses ts_node_eq to check equality between nodes.

* doc/lispref/parsing.texi:
(Accessing Node Information): Update manual.
* src/fns.c (internal_equal): Handle tree-sitter nodes.
* src/treesit.c (treesit_node_eq): New function.
(Ftreesit_node_eq): Factor out.  Update docstring.
* src/treesit.h (treesit_node_eq): Declare new function.

3 files changed, 22 insertions, 7 deletions

diff --git a/src/fns.c b/src/fns.c
index 1aaf17914a2..d5f7565d3d7 100644
--- a/src/fns.c
+++ b/src/fns.c
@@ -38,6 +38,10 @@ along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.  */
 #include "puresize.h"
 #include "gnutls.h"
 
+#ifdef HAVE_TREE_SITTER
+#include "treesit.h"
+#endif
+
 enum equal_kind { EQUAL_NO_QUIT, EQUAL_PLAIN, EQUAL_INCLUDING_PROPERTIES };
 static bool internal_equal (Lisp_Object, Lisp_Object,
                             enum equal_kind, int, Lisp_Object);
@@ -2822,6 +2826,10 @@ internal_equal (Lisp_Object o1, Lisp_Object o2, enum equal_kind equal_kind,
                     && !memcmp (bool_vector_data (o1), bool_vector_data (o2),
                                 bool_vector_bytes (size)));
           }
+        if (TS_NODEP (o1))
+          {
+            return treesit_node_eq (o1, o2);
+          }
 
         /* Aside from them, only true vectors, char-tables, compiled
            functions, and fonts (font-spec, font-entity, font-object)
diff --git a/src/treesit.c b/src/treesit.c
index 55463122d14..d2db91604ab 100644
--- a/src/treesit.c
+++ b/src/treesit.c
@@ -2154,11 +2154,22 @@ If NODE is nil, return nil.  */)
   return make_treesit_node (XTS_NODE (node)->parser, child);
 }
 
+/* Return true if NODE1 and NODE2 are the same node.  Assumes they are
+   TS_NODE type.  */
+bool treesit_node_eq (Lisp_Object node1, Lisp_Object node2)
+{
+  treesit_initialize ();
+  TSNode treesit_node_1 = XTS_NODE (node1)->node;
+  TSNode treesit_node_2 = XTS_NODE (node2)->node;
+  return ts_node_eq (treesit_node_1, treesit_node_2);
+}
+
 DEFUN ("treesit-node-eq",
        Ftreesit_node_eq,
        Streesit_node_eq, 2, 2, 0,
        doc: /* Return non-nil if NODE1 and NODE2 are the same node.
-If any one of NODE1 and NODE2 is nil, return nil.  */)
+If any one of NODE1 and NODE2 is nil, return nil.
+This function uses the same equivalence metric as `equal'.  */)
   (Lisp_Object node1, Lisp_Object node2)
 {
   if (NILP (node1) || NILP (node2))
@@ -2166,12 +2177,7 @@ If any one of NODE1 and NODE2 is nil, return nil.  */)
   CHECK_TS_NODE (node1);
   CHECK_TS_NODE (node2);
 
-  treesit_initialize ();
-
-  TSNode treesit_node_1 = XTS_NODE (node1)->node;
-  TSNode treesit_node_2 = XTS_NODE (node2)->node;
-
-  bool same_node = ts_node_eq (treesit_node_1, treesit_node_2);
+  bool same_node = treesit_node_eq (node1, node2);
   return same_node ? Qt : Qnil;
 }
 
diff --git a/src/treesit.h b/src/treesit.h
index 909609737d3..5382bc58817 100644
--- a/src/treesit.h
+++ b/src/treesit.h
@@ -191,6 +191,7 @@ extern bool treesit_node_uptodate_p (Lisp_Object);
 extern void treesit_delete_parser (struct Lisp_TS_Parser *);
 extern void treesit_delete_query (struct Lisp_TS_Query *);
 extern bool treesit_named_node_p (TSNode);
+extern bool treesit_node_eq (Lisp_Object, Lisp_Object);
 
 #endif  /* HAVE_TREE_SITTER */