Question

I have a problem with Regular Expressions. I want to replace

$[…..] to ${…..}. Only where there is a ‘$’ before ‘{‘.

The following code do almost what I want :

Regex myRegex = new Regex(@"\$\[[^\]]+", RegexOptions.Multiline);

        string myString = "voici le [contenu] de $[ma chaine de caractères] dans un contexte précis $[pour faire des essais] de remplacement";

        while (myRegex.Match(myString).Success)
        {
            Console.WriteLine(myString);
            Console.WriteLine("");
            string myOudString = myRegex.Match(myString).Value+"]";
            Console.WriteLine("myOudString is " + myOudString);

            string myNewString = myOudString.Replace("[", "{");
            myNewString = myNewString.Replace("]", "}");

            myString = myString.Replace(myOudString, myNewString);
        }

But I have a problem with certain string. For example :

string myString = "Here is $[a sample [of] code] to $[replace different] character"

My code will return :

“Here is ${a sample {of} code} to ${replace different} character”.

But I want to return :

“Here is ${a sample [of] code} to ${replace different} character

I hope that anybody can help me.

Thanks!

Answer 1

It is tricky to contrust a “regular” expression for nested parentheses.

If you can assume that there is a maximum one level of nesting then this should work for you:

myString = Regex.Replace(myString, @"\$\[((?:\[.*?\]|.)*?)\]", "${$1}");