Haskell 代数数据类型的派生显示
我有以下几种:Haskell 代数数据类型的派生显示,haskell,types,Haskell,Types,我有以下几种: data Suit = Club | Diamond | Heart | Spade deriving Show data Rank = R2 | R3 | R4 | R5 | R6 | R7 | R8 | R9 | R10 | Jack | Queen | King | Ace deriving Show data JokerColor = Red | Black deriving Show data JCard = NormalCard Suit Rank | JokerCa
data Suit = Club | Diamond | Heart | Spade deriving Show
data Rank = R2 | R3 | R4 | R5 | R6 | R7 | R8 | R9 | R10 | Jack | Queen | King | Ace deriving Show
data JokerColor = Red | Black deriving Show
data JCard = NormalCard Suit Rank | JokerCard JokerColor
我怎样才能展示JCard?目前,我没有(Show JCard)的实例。只需像对
JokerColor
那样派生JCard的Show
data JokerColor = Red | Black deriving Show
data JCard = NormalCard Suit Rank | JokerCard JokerColor deriving Show
对于大多数类型,人们通常会导出Eq、Ord和Show。谢谢!我以前遇到过不相关的错误,我认为这个语法不正确。。。