SubtitileEdit: FixCommonWordErrorsQuick

public string FixCommonWordErrorsQuick(string originalWord)
        {
            var word = originalWord;

            // always replace list
            foreach (var replacementKey in _partialWordAlwaysReplaceList.Keys)
            {
                // ensure replacement can be in word
                if (word.Length >= replacementKey.Length)
                {
                    word = word.Replace(replacementKey, _partialWordAlwaysReplaceList[replacementKey]);
                }
            }

            int l = 0;
            var prefixSymbols = new HashSet<char> { '-', '.', '"', '(', '\r', '\n' };
            var knownOpenTags = new HashSet<string> {"<i>", "<u>", "<b>"};

            for (int r = 0; r < word.Length; r++)
            {
                var c = word[r];
                if (c == '<')
                {
                    l = r;
                }
                else if (c == '>' && word[l] == '<') // tag
                {
                    var tag = word.Substring(l, r - l + 1);
                    if (knownOpenTags.Contains(tag) || tag.StartsWith("<font ", StringComparison.Ordinal))
                    {
                        l = r + 1; // jump tag
                    }
                    else
                    {
                        l = r; // stay in tag and break the loop
                        break;
                    }
                }
                else if (!prefixSymbols.Contains(c))
                {
                    l = r;
                    break;
                }
            }

            // create new word without prefixes
            word = word.Substring(l);

            var suffixSymbols = new HashSet<char> { '"', '.', ',', '?', '!', ')' };
            var knownClosingTags = new HashSet<string> { "</i>", "</b>", "</u>", "</font>" };

            int k = word.Length - 1;
            for (int i = word.Length - 1; i >= 0; i--)
            {
                var c = word[i];
                if (c == '>')
                {
                    k = i;
                }
                else if (c == '<' && word[k] == '>')
                {
                    if (knownClosingTags.Contains(word.Substring(i, k - i - 1)))
                    {
                        k = i; // move k to the beginning of closing tag
                    }
                    // else k doesn't change anything after k is a suffix
                }
                else if (!suffixSymbols.Contains(c))
                {
                    k = i;
                    break;
                }
            }


            // create a word without prefix and suffix
            word = word.Substring(0, k + 1);
            var prefix = originalWord.Substring(0, l);
            var suffix = originalWord.Substring(k + 1);

            if (word.Length == 0)
            {
                return prefix + suffix;
            }

            if (GetReplaceWord(prefix, word, suffix, out var res))
            {
                return res;
            }

            return prefix + word + suffix;
        }