// Copyright 2018 Google Inc. All Rights Reserved.

//

// Licensed 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 NINJA_PARSER_H_

#define NINJA_PARSER_H_

#include <string>

#include "lexer.h"

struct FileReader;

struct State;

/// Base class for parsers.

struct Parser {

  Parser(State* state, FileReader* file_reader)

      : state_(state), file_reader_(file_reader) {}

  virtual ~Parser() {}

  /// Load and parse a file.

  bool Load(const std::string& filename, std::string* err, Lexer* parent = NULL);

protected:

  /// If the next token is not \a expected, produce an error string

  /// saying "expected foo, got bar".

  bool ExpectToken(Lexer::Token expected, std::string* err);

  State* state_;

  FileReader* file_reader_;

  Lexer lexer_;

private:

  /// Parse a file, given its contents as a string.

  virtual bool Parse(const std::string& filename, const std::string& input,

                     std::string* err) = 0;

};

#endif  // NINJA_PARSER_H_