int InternalFindNext(ITextIterator textIterator, int offset, int length)
 {
     while (textIterator.MoveAhead(1) && TextSelection.IsInsideRange(textIterator.Position, offset, length))
     {
         if (SearchOptions.MatchCase ? MatchCaseSensitive(textIterator.TextBuffer, textIterator.Position, searchPattern) : MatchCaseInsensitive(textIterator.TextBuffer, textIterator.Position, searchPattern))
         {
             if (!SearchOptions.MatchWholeWord || IsWholeWordAt(textIterator.TextBuffer, textIterator.Position, searchPattern.Length))
             {
                 if (TextSelection.IsInsideRange(textIterator.Position + searchPattern.Length - 1, offset, length))
                 {
                     return(textIterator.Position);
                 }
                 else
                 {
                     return(-1);
                 }
             }
         }
     }
     return(-1);
 }
        public SearchResultMatch FindNext(ITextIterator textIterator, int offset, int length)
        {
            string document = textIterator.TextBuffer.GetText(0, textIterator.TextBuffer.Length);

            while (textIterator.MoveAhead(1) && TextSelection.IsInsideRange(textIterator.Position, offset, length))
            {
                Match m = regex.Match(document, textIterator.Position);
                if (m == null || !m.Success)
                {
                    while (textIterator.Position < document.Length - 1)
                    {
                        if (!textIterator.MoveAhead(1))
                        {
                            return(null);
                        }
                    }
                }
                else
                {
                    int delta = m.Index - textIterator.Position;
                    if (delta <= 0 || textIterator.MoveAhead(delta))
                    {
                        if (TextSelection.IsInsideRange(m.Index + m.Length - 1, offset, length))
                        {
                            return(new RegexSearchResult(m));
                        }
                        else
                        {
                            return(null);
                        }
                    }
                    else
                    {
                        return(null);
                    }
                }
            }

            return(null);
        }