using uCalcSoftware;

var uc = new uCalc();
var t = uc.NewTransformer();
// Define the data
uc.DefineVariable("user_name = 'Alice'");

// Define the placeholder rule
// '{' is a special character and must be escaped
t.FromTo("'{' '{' {expr} '}' '}'", "{@@Eval: expr}");

// Process the template
Console.WriteLine(t.Transform("Hello, {{ user_name }}!"));