我想制作从对列表中返回每对中的乘法元素列表的函数.例如:
>product [1,2] [3,4]
[3,8]
我想用这个来做list comprehension.我试过这样的事情:
product :: Num a => [a] -> [a] -> [a]
product xs ys = [x*y | z<-zip xs ys, (x, _)<-z, (_, y)<-z]
但它不起作用.应该改变什么？