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这里是我的代码:大小的树,而不是在范围
data Binary_Tree a = Null
|Node {element :: a, left_tree, right_tree :: Binary_Tree a}
deriving (Show, Eq)
--depth_of_tree
dot :: Integral b => Binary_Tree a -> b
dot Null = 0
dot Node (a left right) = 1 + (dot Node (a left right)) + (dot Node (a left right))
然而,当我加载它在ghci中它,并输入
dot Node (2 (Node 3 Null Null) Null)
它出来一个错误:
<interactive>:13:1:
Not in scope: `dot'
Perhaps you meant `not' (imported from Prelude)
任何人都喜欢告诉我我的代码有什么问题吗?
感谢任何人谁可以很好我一些建议XD