如何在Haskell中生成具有自己的数据类型的列表

Question

I am trying to create an infinite list with my own data type in haskell

data Color = Black | White       deriving (Show, Eq)
data Cell  = Empty | Stone Color deriving (Show, Eq)

makeRow :: Int -> Row
makeRow 0 = []
makeRow n = take n (repeat Cell Empty)

And it gives me the error :

Data constructor not in scope: Cell

Answer 1

You get this error because Cell is - indeed - not a value constructor. Just use plain Empty instead (note that you don't write Bool True or Bool False - you just write True or False ).