using uCalcSoftware;

var uc = new uCalc();
// 1. Create a uCalc.String with a parent uCalc instance
using (var s = new uCalc.String(uc, "The user is <admin>.")) {
   // 2. Use the fluent, token-aware API
   s.After("is").Between("<", ">").ToUpper();

   // 3. The original string is modified in-place
   Console.WriteLine(s);
};