IntersectionParser.cs 1.9 KB

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  1. /// Spart License (zlib/png)
  2. ///
  3. ///
  4. /// Copyright (c) 2003 Jonathan de Halleux
  5. ///
  6. /// This software is provided 'as-is', without any express or implied warranty.
  7. /// In no event will the authors be held liable for any damages arising from
  8. /// the use of this software.
  9. ///
  10. /// Permission is granted to anyone to use this software for any purpose,
  11. /// including commercial applications, and to alter it and redistribute it
  12. /// freely, subject to the following restrictions:
  13. ///
  14. /// 1. The origin of this software must not be misrepresented; you must not
  15. /// claim that you wrote the original software. If you use this software in a
  16. /// product, an acknowledgment in the product documentation would be
  17. /// appreciated but is not required.
  18. ///
  19. /// 2. Altered source versions must be plainly marked as such, and must not be
  20. /// misrepresented as being the original software.
  21. ///
  22. /// 3. This notice may not be removed or altered from any source distribution.
  23. ///
  24. /// Author: Jonathan de Halleuxusing System;
  25. namespace Spart.Parsers.Composite
  26. {
  27. using Spart.Scanners;
  28. public class IntersectionParser : BinaryTerminalParser
  29. {
  30. public IntersectionParser(Parser first, Parser second)
  31. :base(first,second)
  32. {}
  33. public override ParserMatch ParseMain(IScanner scan)
  34. {
  35. long offset = scan.Offset;
  36. ParserMatch m = FirstParser.Parse(scan);
  37. if (m.Success)
  38. {
  39. scan.Seek(offset);
  40. ParserMatch m2 = SecondParser.Parse(scan);
  41. if (m2.Success)
  42. {
  43. if (m.Length >= m2.Length)
  44. {
  45. scan.Seek(m.Offset + m.Length);
  46. return m;
  47. }
  48. else
  49. {
  50. return m2;
  51. }
  52. }
  53. }
  54. scan.Seek(offset);
  55. return scan.NoMatch;
  56. }
  57. public override Parser Clone()
  58. {
  59. return base.Clone();
  60. }
  61. }
  62. }