public static void Print(this AdditionExpression ae, StringBuilder sb)
{
sb.Append("(");
ae.Left.Print(sb);
sb.Append("+");
ae.Right.Print(sb);
sb.Append(")");
}
private static void Main(string[] args)
{
var e = new AdditionExpression(
left: new DoubleExpression(1),
right: new AdditionExpression(
left: new DoubleExpression(2),
right: new DoubleExpression(3)));
var sb = new StringBuilder();
e.Print(sb);
WriteLine(sb);
// what is more likely: new type or new operation
}
