public static string Match(string regExp, string inputString)
{
StringBuilder sb = new StringBuilder();
bool ignoreOnMatch = regExp.ToLower().Contains("(?#ignore");
try
{
//extract the function definitions from the expression
ProcessedData pd = ExtractFunctions(regExp);
Regex re = new Regex(pd.regExp);
string[] groupNames = re.GetGroupNames();
//process the expression
MatchCollection collections = Regex.Matches(inputString, pd.regExp);
//apply function expressions to matching groups
//concatinate all the results
foreach (Match match in collections)
{
GroupCollection gc = match.Groups;
for (int x = 1; x < gc.Count; x++)
{
string groupName = groupNames[x];
//see if the group name refers to a defined function
RegExFunction functionRegEx = null;
if (pd.functionList != null)
{
foreach (RegExFunction fncInfo in pd.functionList)
{
if (Regex.IsMatch(groupName, fncInfo.name + @"\d+")) //we have a match, save the function
{
functionRegEx = fncInfo;
break;
}
}
}
if (functionRegEx != null) //we have a function, apply the function expression and use the result
{
if (functionRegEx.literalText)
{
sb.Append(functionRegEx.regExp);
}
else
{
sb.Append(Match(functionRegEx.regExp, gc[x].Value));
}
}
else //no function used
{
sb.Append(gc[x].Value);
}
}
}
}
catch (System.Exception)
{
sb.Length = 0;
}
if (ignoreOnMatch && sb.Length != 0)
{
sb.Clear();
sb.Append("Ignore");
}
return(sb.ToString());
}
private static ProcessedData ExtractFunctions(string regExp)
{
ProcessedData pd = new ProcessedData();
//look for literal text functions first
while (regExp.Contains("(???<")) //while we have a function
{
int nameEnd = -1, depth = 0, start = regExp.IndexOf("(???<"), end = start;
//find the end of the function
do //look for ) matching the starting (
{
if (nameEnd == -1 && regExp[end] == '>')
{
nameEnd = end;
}
if (regExp[end] == '(')
{
depth++;
}
if (regExp[end] == ')' && regExp[end - 1] != '\\')
{
depth--;
}
end++;
} while (!(regExp[end - 1] == ')' && depth == 0));
if (pd.functionList == null)
{
pd.functionList = new List <RegExFunction>();
}
RegExFunction rxf = new RegExFunction();
rxf.name = regExp.Substring(start + 5, nameEnd - (start + 5));
rxf.regExp = regExp.Substring(nameEnd + 2, (end - 2) - (nameEnd + 2));
rxf.literalText = true;
pd.functionList.Add(rxf);
regExp = regExp.Substring(0, start) + regExp.Substring(end); //remove the function definition
}
while (regExp.Contains("(??<")) //while we have a function
{
int nameEnd = -1, depth = 0, start = regExp.IndexOf("(??<"), end = start;
//find the end of the function
do //look for ) matching the starting (
{
if (nameEnd == -1 && regExp[end] == '>')
{
nameEnd = end;
}
if (regExp[end] == '(')
{
depth++;
}
if (regExp[end] == ')')
{
depth--;
}
end++;
} while(!(regExp[end - 1] == ')' && depth == 0));
if (pd.functionList == null)
{
pd.functionList = new List <RegExFunction>();
}
RegExFunction rxf = new RegExFunction();
rxf.name = regExp.Substring(start + 4, nameEnd - (start + 4));
rxf.regExp = regExp.Substring(nameEnd + 1, (end - 1) - (nameEnd + 1));
pd.functionList.Add(rxf);
regExp = regExp.Substring(0, start) + regExp.Substring(end); //remove the function definition
}
pd.regExp = regExp; //the regex with the function definitions removed
return(pd);
}
