void TextBufferChanged(int position, int newLength, int dif)
{
int startLex = Math.Max(position - _lookahead, 0);
EnsureLexed(Buffer.CurrentSnapshot, startLex);
if (dif > 0)
{
_tokens.InsertSpace(position, dif);
}
else if (_tokens.Count > position)
{
_tokens.RemoveRange(position, Math.Min(-dif, _tokens.Count - position));
}
int endLex = position + newLength + _lookahead;
endLex = _tokens.NextHigherIndex(endLex - 1) ?? _tokens.Count;
startLex = _tokens.NextLowerIndex(startLex + 1) ?? 0;
_lexer = PrepareLexer(_lexer, _wrappedBuffer, startLex);
int stoppedAt = RunLexerUntil(endLex);
if (ClassificationChanged != null)
{
var span = new SnapshotSpan(Buffer.CurrentSnapshot, new Span(startLex, stoppedAt - startLex));
ClassificationChanged(this, new ClassificationChangedEventArgs(span));
}
}