// The MIT License (MIT)
//
// Copyright (c) 2013-2019 Khan Academy and other contributors
// Copyright (c) 2020 znjameswu <znjameswu@gmail.com>
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.

import 'lexer.dart';
import 'token.dart';

class SourceLocation {
  final LexerInterface lexer;
  final int start;
  final int end;
  SourceLocation(this.lexer, this.start, this.end);

  static SourceLocation? range(Token first, [Token? second]) {
    if (second == null) {
      return first.loc;
    } else if (first.loc == null ||
        second.loc == null ||
        first.loc!.lexer != second.loc!.lexer) {
      return null;
    } else {
      return SourceLocation(
          first.loc!.lexer, first.loc!.start, second.loc!.end);
    }
  }
}