LayoutFarm.TextBreak.WordGroup.GetWordSpans C# (CSharp) Method

        internal WordSpan[] GetWordSpans() { return wordSpans; }
        internal WordGroup[] GetSubGroups() { return subGroups; }

        int FindInWordSpans(WordVisitor visitor, WordGroup wordGroup)
        {
            WordSpan[] wordSpans = wordGroup.GetWordSpans();
            if (wordSpans == null)
            {
                throw new NotSupportedException();
            }

            //at this wordgroup
            //no subground anymore
            //so we should find the word one by one
            //start at prefix
            //and select the one that 

            int readLen = visitor.CurrentIndex - visitor.LatestBreakAt;
            int nwords = wordSpans.Length;
            //only 1 that match 

            TextBuffer currentTextBuffer = CurrentCustomDic.TextBuffer;

            //we sort unindex string ***
            //so we find from longest one( last) to begin 
            for (int i = nwords - 1; i >= 0; --i)
            {
                //loop test on each word
                WordSpan w = wordSpans[i];
#if DEBUG
                //string dbugstr = w.GetString(currentTextBuffer);
#endif

                int savedIndex = visitor.CurrentIndex;
                char c = visitor.Char;
                int wordLen = w.len;
                int matchCharCount = 0;
                if (wordLen > readLen)
                {
                    for (int p = readLen; p < wordLen; ++p)
                    {
                        char c2 = w.GetChar(p, currentTextBuffer);
                        if (c2 == c)
                        {
                            matchCharCount++;
                            //match 
                            //read next
                            if (!visitor.IsEnd)
                            {
                                visitor.SetCurrentIndex(visitor.CurrentIndex + 1);
                                c = visitor.Char;
                            }
                            else
                            {
                                //no more data in visitor

                                break;
                            }
                        }
                        else
                        {
                            break;
                        }
                    }
                }
                //reset
                if (readLen + matchCharCount == wordLen)
                {
                    int newBreakAt = visitor.LatestBreakAt + wordLen;
                    visitor.SetCurrentIndex(newBreakAt);
                    //-------------------------------------------- 
                    if (visitor.State == VisitorState.End)
                    {
                        return newBreakAt;
                    }
                    //check next char can be the char of new word or not
                    //this depends on each lang 
                    char canBeStartChar = visitor.Char;
                    if (CanHandle(canBeStartChar))
                    {
                        if (CanBeStartChar(canBeStartChar))
                        {
                            return newBreakAt;
                        }
                        else
                        {
                            //back to savedIndex
                            visitor.SetCurrentIndex(savedIndex);
                            return savedIndex;
                        }
                    }
                    else
                    {
                        visitor.State = VisitorState.OutOfRangeChar;
                        return newBreakAt;
                    }
                }
                visitor.SetCurrentIndex(savedIndex);
            }
            return 0;
        }