Simplify storage of position on nodes

spec/runtime/tree_spec.cc

@@ -91,10 +91,7 @@ describe("Tree", []() {
       AssertThat(children[0].offset.chars, Equals<size_t>(0));
 
       AssertThat(children[1].tree, Equals(tree2));
-      AssertThat(children[1].offset.bytes, Equals<size_t>(
-          tree1->size.bytes + tree2->padding.bytes));
-      AssertThat(children[1].offset.chars, Equals<size_t>(
-          tree1->size.chars + tree2->padding.chars));
+      AssertThat(children[1].offset, Equals(ts_tree_total_size(tree1)));
     });
 
     describe("when one of the child nodes is hidden", [&]() {
@@ -128,16 +125,10 @@ describe("Tree", []() {
         AssertThat(children[0].offset.chars, Equals<size_t>(0));
 
         AssertThat(children[1].tree, Equals(tree2));
-        AssertThat(children[1].offset.bytes, Equals<size_t>(
-          tree1->size.bytes + tree2->padding.bytes));
-        AssertThat(children[1].offset.chars, Equals<size_t>(
-          tree1->size.chars + tree2->padding.chars));
+        AssertThat(children[1].offset, Equals(ts_tree_total_size(tree1)));
 
         AssertThat(children[2].tree, Equals(tree3));
-        AssertThat(children[2].offset.bytes, Equals<size_t>(
-          tree1->size.bytes + tree2->padding.bytes + tree2->size.bytes + tree3->padding.bytes));
-        AssertThat(children[2].offset.chars, Equals<size_t>(
-          tree1->size.chars + tree2->padding.chars + tree2->size.chars + tree3->padding.chars));
+        AssertThat(children[2].offset, Equals(ts_length_add(ts_tree_total_size(tree1), ts_tree_total_size(tree2))));
       });
     });
 
@@ -303,3 +294,7 @@ describe("Tree", []() {
 });
 
 END_TEST
+
+bool operator==(TSLength left, TSLength right) {
+  return ts_length_eq(left, right);
+}

src/runtime/document.c

@@ -63,7 +63,7 @@ void ts_document_set_input_string(TSDocument *document, const char *text) {
 
 TSNode ts_document_root_node(const TSDocument *document) {
   if (document->tree)
-    return ts_node_make(document->tree, document->tree->padding);
+    return ts_node_make(document->tree, ts_length_zero());
   else
     return ts_node_null();
 }

src/runtime/node.c

@@ -13,7 +13,7 @@ static inline const TSTree *get_tree(TSNode this) {
 }
 
 TSLength ts_node_pos(TSNode this) {
-  return this.position;
+  return ts_length_add(this.position, get_tree(this)->padding);
 }
 
 TSLength ts_node_size(TSNode this) {
@@ -41,7 +41,7 @@ typedef struct {
 static inline NodeWithIndex ts_node_parent_with_index(TSNode this) {
   const TSTree *tree = get_tree(this);
   size_t index = 0;
-  TSLength position = ts_length_sub(this.position, tree->padding);
+  TSLength position = this.position;
 
   do {
     TSTree *parent = tree->parent;
@@ -64,9 +64,7 @@ static inline NodeWithIndex ts_node_parent_with_index(TSNode this) {
     tree = parent;
   } while (!ts_tree_is_visible(tree));
 
-  return (NodeWithIndex){
-    ts_node_make(tree, ts_length_add(position, tree->padding)), index
-  };
+  return (NodeWithIndex){ ts_node_make(tree, position), index };
 }
 
 TSNode ts_node_parent(TSNode this) {

src/runtime/tree.c

@@ -101,9 +101,6 @@ TSTree *ts_tree_make_node(TSSymbol symbol, size_t child_count,
     TSTree *child = children[i];
     child->parent = result;
 
-    if (i > 0)
-      offset = ts_length_add(offset, child->padding);
-
     if (ts_tree_is_visible(child)) {
       visible_children[vis_i].tree = child;
       visible_children[vis_i].offset = offset;
@@ -119,7 +116,7 @@ TSTree *ts_tree_make_node(TSSymbol symbol, size_t child_count,
       }
     }
 
-    offset = ts_length_add(offset, child->size);
+    offset = ts_length_add(offset, ts_tree_total_size(child));
   }
 
   return result;