Alphashack.Graphdat.Agent.SqlQueryHelper.Parser.Substitute C# (CSharp) Method

        public string Substitute(string subject, string regex, string replace, RegexOption option = DefaultOption, int offset = 0)
        {
            // Special cases, if $N is passed then use the substring as the replacement
            // if #N is passed then use substring, pad with a space on either side
            var group = -1;
            var substituteGroup = replace.Length == 2 && (replace[0] == '$' || replace[0] == '#') &&
                                   int.TryParse(replace[1].ToString(), out group);
            var pad = !substituteGroup ? false : replace[0] == '#';

            var r = new Regex(regex, option);
            var match = r.Execute(subject);

            var replacements = new List<Replacement>();

            while (match.Success)
            {
                if (match.Groups[0].Start >= offset)
                {
                    var doReplace = false;
                    if (substituteGroup)
                    {
                        if (match.Groups.Count > group)
                        {
                            doReplace = true;
                            replace = string.Format("{0}{1}{0}", pad ? " " : "", match.Groups[group].Value);
                        }
                    }
                    else
                    {
                        doReplace = true;
                    }

                    if (doReplace)
                    {
                        replacements.Add(new Replacement
                                             {
                                                 Start = match.Groups[0].Start,
                                                 Length = match.Groups[0].Length,
                                                 Value = replace
                                             });
                    }
                }

                match = match.NextMatch;
            }

            replacements.Reverse();
            foreach (var replacement in replacements)
            {
                subject = subject.Remove(replacement.Start, replacement.Length);
                subject = subject.Insert(replacement.Start, replacement.Value);
            }

            return subject;
        }