纯Lambda实现斐波那契数列

还需要考虑溢出等问题，闲来无事写了写

Func<float, float, float> a = (arg1, arg2) => 0f;//init

var depth = ;
a = (lastNumber, currentNumber) =>
    {
        if (depth <= ) return currentNumber;
        depth--;
        return a(currentNumber, currentNumber + lastNumber);
    };

var result = a(, );