/// <summary>
/// Inner parse method
/// </summary>
/// <param name="scanner">scanner</param>
/// <returns>the match</returns>
protected override ParserMatch ParseMain(Scanners.IScanner scanner)
{
ParserMatch m = FirstParser.TryAccept(scanner);
if (!m.Success)
{
return(m);
}
// doing difference
ParserMatch d = SecondParser.TryAccept(scanner);
if (d.Success)
{
if (d.Length >= m.Length)
{
return(ParserMatch.CreateFailureMatch(scanner, m.Offset, 0));
}
}
// ok
FirstParser.Parse(scanner);
return(m);
}
/// <summary>
/// Inner parse method
/// match (first but not second) or (second but not first)
/// </summary>
/// <param name="scanner">scanner</param>
/// <returns>the match</returns>
protected override ParserMatch ParseMain(Scanners.IScanner scanner)
{
long startOffset = scanner.Offset;
ParserMatch m1 = FirstParser.Parse(scanner);
long offset1 = scanner.Offset;
scanner.Seek(startOffset);
ParserMatch m2 = SecondParser.Parse(scanner);
if (m1.Success && !m2.Success)
{
scanner.Seek(offset1);
return(m1);
}
if (m2.Success && !m1.Success)
{
return(m2);
}
scanner.Seek(startOffset);
return(ParserMatch.CreateFailureMatch(scanner));
}
