Question

我正在调试我的霍夫曼解码功能

decode :: (Tree a, [Bit]) -> [a]
decode (tree, list) = case list of
 [] -> case tree of
   Leaf pos a -> replicate_Pos pos a
 _  -> (num_only (follow_bit_path_to_one_value tree list)): huffman_decode (tree, (list_only (follow_bit_path_to_one_value tree list))
   where 
    num_only :: (a, [Bit]) -> a
    num_only (a, _) -> a
    list_only:: (a, [Bit]) -> [Bit]
    list_only (_, list) -> list

它在输入时出现了解析错误＆＃34;其中＆＃34;？我哪里做错了？

Answer 1

这段代码的真正问题实际上是不匹配的括号 - 而不是case表达式中的缩进。此外，辅助函数中还有箭头而不是=符号。

以下代码解析得很好。

decode :: (Tree a, [Bit]) -> [a]
decode (tree, list) = case list of
 [] -> case tree of
   Leaf pos a -> replicate_Pos pos a
 _  -> (num_only (follow_bit_path_to_one_value tree list)): huffman_decode (tree, (list_only (follow_bit_path_to_one_value tree list)))
   where 
    num_only :: (a, [Bit]) -> a
    num_only (a, _) = a
    list_only:: (a, [Bit]) -> [Bit]
    list_only (_, list) = list

调试霍夫曼解码

1 个答案: