public LazyBinaryOp(OP _x, String _Op, OP _y)
{
x = _x;
Op = _Op;
y = _y;
if (funcs == null)
{
funcs = new Dictionary <String, Func <OP, OP, Tuple <int, string> > >();
funcs.Add("{", (x, y) =>
{
var count = x.eval();
var acc = 0;
var msg = count.Item2 + "{";
for (int i = 0; i < count.Item1; i++)
{
var res = y.eval();
acc += res.Item1;
if (i > 0)
{
msg += " + " + res.Item2;
}
else
{
msg += res.Item2;
}
}
msg += "}";
return(Tuple.Create(acc, msg));
}
);
}
}
public override Tuple <int, string> eval()
{
return(funcs[Op](x.eval()));
}