/// <summary>
/// Incrementally lexes and parses the specified string.
/// </summary>
private IncrementalResult ParseIncremental <TSource>(TSource input, Int32 start, Int32 count, TextParserTokenStream output, TextParserOptions options = TextParserOptions.None)
where TSource : ISegmentableStringSource
{
var inputLengthOld = output.SourceText.Length;
var inputLengthNew = input.Length;
var inputLengthDiff = inputLengthNew - inputLengthOld;
Int32 ix1, ix2;
FindTokensInfluencedBySubstring(output, start, count - inputLengthDiff, out ix1, out ix2);
var token1 = output[ix1];
var token2 = output[ix2];
var invalidatedTokenCount = 1 + (ix2 - ix1);
output.RemoveRange(ix1, invalidatedTokenCount);
var lexStart = token1.SourceOffset;
var lexCount = inputLengthDiff + (token2.SourceOffset + token2.SourceLength) - lexStart;
var parserBuffer = incrementalParserBuffer.Value;
Parse(input, parserBuffer, lexStart, lexCount);
output.SourceText = input.CreateStringSegment();
output.InsertRange(ix1, parserBuffer);
var affectedOffset = ix1;
var affectedCount = parserBuffer.Count;
parserBuffer.Clear();
return(new IncrementalResult(affectedOffset, affectedCount));
}
