static void Main(string[] args)
{
var e = new AdditionExpression(
left: new DoubleExpression(1),
right: new AdditionExpression(
left: new DoubleExpression(2),
right: new DoubleExpression(3)
)
);
// INTRUSIVE EXPRESSION PRINTING - NOT VISITOR PATTERN
//var sb = new StringBuilder();
//e.Print(sb);
//Console.WriteLine(sb);
// what is more likely: new type or new operation
// REFLECTION BASED PRINTING - STILL NOT USING VISITOR PATTERN
//var sb = new StringBuilder();
//ExpressionPrinter.Print2(e, sb);
//Console.WriteLine(sb);
// CLASSIC VISITOR
//var ep = new ExpressionPrinter();
//ep.Visit(e);
//Console.WriteLine(ep.ToString());
//var calc = new ExpressionCalculator();
//calc.Visit(e);
//Console.WriteLine($"{ep} = {calc.Result}");
// DYNAMIC VISITOR
var ep = new ExpressionPrinter();
var sb = new StringBuilder();
ep.Print((dynamic)e, sb);
Console.WriteLine(sb);
// disadvantages:
// 1) Performance penalty
// 2) Runtime error on missing visitor
// 3) Problematic w.r.t. inheritance
Console.ReadLine();
}
void Main(string[] args)
{
Expression e = new AdditionExpression(
new DoubleExpression(1),
new AdditionExpression(
new DoubleExpression(2),
new DoubleExpression(3)));
var ep = new ExpressionPrinter();
var sb = new StringBuilder();
ep.Print((dynamic)e, sb);
Console.WriteLine(sb);
}