小编Hun*_*jos的帖子

我试图覆盖+符号,以学习如何定义自己的类型.我是Haskell的新手,我似乎无法克服这个错误.

这是我简单的新类型:

newtype Matrix x = Matrix x
(+):: (Num a, Num b, Num c) => Matrix [[a]] -> Matrix [[b]] -> Matrix [[c]]
x + y = Matrix zipWith (\ a b -> zipWith (+) a b) x y

当我尝试将其加载到ghci时,我收到错误

linear_algebra.hs:9:42:
    Ambiguous occurrence ‘+’
    It could refer to either ‘Main.+’, defined at linear_algebra.hs:9:3
                          or ‘Prelude.+’,
                             imported from ‘Prelude’ at linear_algebra.hs:1:1
                             (and originally defined in ‘GHC.Num’)
Failed, modules loaded: none.

用我的代码替换我的最后一行代码

x + y = Matrix zipWith (\ a b …