Method PreVisitComprehension

eval/compiler/flat_expr_builder.cc:1290–1382

  }

  void PreVisitComprehension(
      const cel::Expr& expr,
      const cel::ComprehensionExpr& comprehension) override {
    if (!progress_status_.ok()) {
      return;
    }
    if (!ValidateOrError(options_.enable_comprehension,
                         "Comprehension support is disabled")) {
      return;
    }
    const auto& accu_var = comprehension.accu_var();
    const auto& iter_var = comprehension.iter_var();
    const auto& iter_var2 = comprehension.iter_var2();
    ValidateOrError(!accu_var.empty(),
                    "Invalid comprehension: 'accu_var' must not be empty");
    ValidateOrError(!iter_var.empty(),
                    "Invalid comprehension: 'iter_var' must not be empty");
    ValidateOrError(
        accu_var != iter_var,
        "Invalid comprehension: 'accu_var' must not be the same as 'iter_var'");
    ValidateOrError(accu_var != iter_var2,
                    "Invalid comprehension: 'accu_var' must not be the same as "
                    "'iter_var2'");
    ValidateOrError(iter_var2 != iter_var,
                    "Invalid comprehension: 'iter_var2' must not be the same "
                    "as 'iter_var'");
    ValidateOrError(comprehension.has_accu_init(),
                    "Invalid comprehension: 'accu_init' must be set");
    ValidateOrError(comprehension.has_loop_condition(),
                    "Invalid comprehension: 'loop_condition' must be set");
    ValidateOrError(comprehension.has_loop_step(),
                    "Invalid comprehension: 'loop_step' must be set");
    ValidateOrError(comprehension.has_result(),
                    "Invalid comprehension: 'result' must be set");

    size_t iter_slot, iter2_slot, accu_slot, slot_count;
    bool is_bind = IsBind(&comprehension);

    if (is_bind) {
      accu_slot = iter_slot = iter2_slot = index_manager_.ReserveSlots(1);
      slot_count = 1;
    } else if (comprehension.iter_var2().empty()) {
      iter_slot = iter2_slot = index_manager_.ReserveSlots(2);
      accu_slot = iter_slot + 1;
      slot_count = 2;
    } else {
      iter_slot = index_manager_.ReserveSlots(3);
      iter2_slot = iter_slot + 1;
      accu_slot = iter2_slot + 1;
      slot_count = 3;
    }

    if (block_.has_value()) {
      BlockInfo& block = *block_;
      if (block.in) {
        block.slot_count += slot_count;
        slot_count = 0;
      }