text: /*
   * Copyright (c) 2019 Google LLC.
   *
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements.  See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership.  The ASF licenses this file
   * to you under the Apache License, Version 2.0 (the
   * "License"); you may not use this file except in compliance
   * with the License.  You may obtain a copy of the License at
   *
   *   http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing,
   * software distributed under the License is distributed on an
   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
   * KIND, either express or implied.  See the License for the
   * specific language governing permissions and limitations
   * under the License.
   *
   */
  #ifndef SFDB_ENGINE_INFER_RESULT_TYPES_H_
  #define SFDB_ENGINE_INFER_RESULT_TYPES_H_
  
  #include <memory>
  
  #include "absl/base/thread_annotations.h"
  #include "sfdb/base/ast.h"
  #include "sfdb/base/ast_type.h"
  #include "sfdb/base/db.h"
  #include "sfdb/proto/pool.h"
  #include "util/task/statusor.h"
  
  namespace sfdb {
  
  ::util::StatusOr<std::unique_ptr<Ast>> ExpandAst(
      std::unique_ptr<Ast> &&ast, ProtoPool *pool, const Db *db, const Vars *vars)
      SHARED_LOCKS_REQUIRED(db->mu);
  
  // Computes the result type for the given AST and its descendants, recursively.
  // Uses |vars| as the var context; set it to db->vars for ASTs executed in |db|.
  //
  // Destroys the given Ast object and uses its spare parts to build a TypedAst.
  ::util::StatusOr<std::unique_ptr<TypedAst>> InferResultTypes(
      std::unique_ptr<Ast> &&ast, ProtoPool *pool, const Db *db, const Vars *vars)
      SHARED_LOCKS_REQUIRED(db->mu);
  
  }  // namespace sfdb
  
  #endif  // SFDB_ENGINE_INFER_RESULT_TYPES_H_
  