private static INode BuildSubNodes(INode lhs, TokenBuffer tokens)
{
var mulDivOp = MulDivOp.Produce(tokens);
if (mulDivOp == null)
return lhs;
var rhs = ExpRoot.Produce(tokens);
if (rhs == null)
{
tokens.RestorePosition();
return lhs;
}
lhs = new MulDiv(lhs, mulDivOp, rhs);
return BuildSubNodes(lhs, tokens);
}
/// <summary>
/// 代理
/// </summary>
private static void testDelegate()
{
AddSub ass = new AddSub();
MulDiv md = new MulDiv();
Calculate add = new Calculate(ass.add);
Calculate sub = new Calculate(ass.sub);
Calculate mul = new Calculate(md.mul);
Calculate div = new Calculate(md.div);
Console.WriteLine("{0} + {1} = {2}", 2, 3, add(2, 3));
Console.WriteLine("{0} - {1} = {2}", 4, 5, sub(4, 5));
Console.WriteLine("{0} * {1} = {2}", 6, 7, mul(6, 7));
Console.WriteLine("{0} / {1} = {2}", 9, 3, div(9, 3));
//组合代理
Calculate cc = ass.add;
cc += ass.sub;//add 和 sub都会执行
Console.WriteLine("{0} // {1} = {2}", 9, 3, cc(9, 3));
cc -= ass.sub;//去掉sub 只执行add方法
Console.WriteLine("{0} // {1} = {2}", 9, 3, cc(9, 3));
}