相关疑难解决方法(0)

可能重复:
你能在haskell中超载吗？

你能实现一个可以在两个矩阵上工作的Matrix类和*运算符吗？:

scala> val x = Matrix(3, 1,2,3,4,5,6)  
x: Matrix =   
[1.0, 2.0, 3.0]  
[4.0, 5.0, 6.0]  

scala> x*x.transpose  
res0: Matrix =   
[14.0, 32.0]  
[32.0, 77.0]  

所以人们不会说这很难,这就是Scala的实现(由Jonathan Merritt提供):

class Matrix(els: List[List[Double]]) {  

    /** elements of the matrix, stored as a list of  
      its rows */  
    val elements: List[List[Double]] = els  
    def nRows: Int = elements.length  
    def nCols: Int = if (elements.isEmpty) 0   
                     else elements.head.length  

    /** all rows of the matrix must have the same  
        number of columns …