void ts_subtree_set_children()

in lib/src/subtree.c [362:474]

• 95 lines of code
• 33 McCabe index (conditional complexity)

void ts_subtree_set_children(
  MutableSubtree self, Subtree *children, uint32_t child_count, const TSLanguage *language
) {
  assert(!self.data.is_inline);

  if (self.ptr->child_count > 0 && children != self.ptr->children) {
    ts_free(self.ptr->children);
  }

  self.ptr->child_count = child_count;
  self.ptr->children = children;
  self.ptr->named_child_count = 0;
  self.ptr->visible_child_count = 0;
  self.ptr->error_cost = 0;
  self.ptr->repeat_depth = 0;
  self.ptr->node_count = 1;
  self.ptr->has_external_tokens = false;
  self.ptr->dynamic_precedence = 0;

  uint32_t non_extra_index = 0;
  const TSSymbol *alias_sequence = ts_language_alias_sequence(language, self.ptr->production_id);
  uint32_t lookahead_end_byte = 0;

  for (uint32_t i = 0; i < self.ptr->child_count; i++) {
    Subtree child = self.ptr->children[i];

    if (i == 0) {
      self.ptr->padding = ts_subtree_padding(child);
      self.ptr->size = ts_subtree_size(child);
    } else {
      self.ptr->size = length_add(self.ptr->size, ts_subtree_total_size(child));
    }

    uint32_t child_lookahead_end_byte =
      self.ptr->padding.bytes +
      self.ptr->size.bytes +
      ts_subtree_lookahead_bytes(child);
    if (child_lookahead_end_byte > lookahead_end_byte) lookahead_end_byte = child_lookahead_end_byte;

    if (ts_subtree_symbol(child) != ts_builtin_sym_error_repeat) {
      self.ptr->error_cost += ts_subtree_error_cost(child);
    }

    self.ptr->dynamic_precedence += ts_subtree_dynamic_precedence(child);
    self.ptr->node_count += ts_subtree_node_count(child);

    if (alias_sequence && alias_sequence[non_extra_index] != 0 && !ts_subtree_extra(child)) {
      self.ptr->visible_child_count++;
      if (ts_language_symbol_metadata(language, alias_sequence[non_extra_index]).named) {
        self.ptr->named_child_count++;
      }
    } else if (ts_subtree_visible(child)) {
      self.ptr->visible_child_count++;
      if (ts_subtree_named(child)) self.ptr->named_child_count++;
    } else if (ts_subtree_child_count(child) > 0) {
      self.ptr->visible_child_count += child.ptr->visible_child_count;
      self.ptr->named_child_count += child.ptr->named_child_count;
    }

    if (ts_subtree_has_external_tokens(child)) self.ptr->has_external_tokens = true;

    if (ts_subtree_is_error(child)) {
      self.ptr->fragile_left = self.ptr->fragile_right = true;
      self.ptr->parse_state = TS_TREE_STATE_NONE;
    }

    if (!ts_subtree_extra(child)) non_extra_index++;
  }

  self.ptr->lookahead_bytes = lookahead_end_byte - self.ptr->size.bytes - self.ptr->padding.bytes;

  if (self.ptr->symbol == ts_builtin_sym_error || self.ptr->symbol == ts_builtin_sym_error_repeat) {
    self.ptr->error_cost +=
      ERROR_COST_PER_RECOVERY +
      ERROR_COST_PER_SKIPPED_CHAR * self.ptr->size.bytes +
      ERROR_COST_PER_SKIPPED_LINE * self.ptr->size.extent.row;
    for (uint32_t i = 0; i < self.ptr->child_count; i++) {
      Subtree child = self.ptr->children[i];
      uint32_t grandchild_count = ts_subtree_child_count(child);
      if (ts_subtree_extra(child)) continue;
      if (ts_subtree_is_error(child) && grandchild_count == 0) continue;
      if (ts_subtree_visible(child)) {
        self.ptr->error_cost += ERROR_COST_PER_SKIPPED_TREE;
      } else if (grandchild_count > 0) {
        self.ptr->error_cost += ERROR_COST_PER_SKIPPED_TREE * child.ptr->visible_child_count;
      }
    }
  }

  if (self.ptr->child_count > 0) {
    Subtree first_child = self.ptr->children[0];
    Subtree last_child = self.ptr->children[self.ptr->child_count - 1];

    self.ptr->first_leaf.symbol = ts_subtree_leaf_symbol(first_child);
    self.ptr->first_leaf.parse_state = ts_subtree_leaf_parse_state(first_child);

    if (ts_subtree_fragile_left(first_child)) self.ptr->fragile_left = true;
    if (ts_subtree_fragile_right(last_child)) self.ptr->fragile_right = true;

    if (
      self.ptr->child_count >= 2 &&
      !self.ptr->visible &&
      !self.ptr->named &&
      ts_subtree_symbol(first_child) == self.ptr->symbol
    ) {
      if (ts_subtree_repeat_depth(first_child) > ts_subtree_repeat_depth(last_child)) {
        self.ptr->repeat_depth = ts_subtree_repeat_depth(first_child) + 1;
      } else {
        self.ptr->repeat_depth = ts_subtree_repeat_depth(last_child) + 1;
      }
    }
  }
}