在Haskell中将列表拆分为列表列表

decodeText

应该

split'

将每个单词的代码分成更小的列表

code

。然后将单词中每个字符的

code

列表拆分为更小的

code

decodeText :: Table -> Code -> String
decodeText table code=  map (split' shortGap) (split' mediumGap code)

当我加载程序时，此代码给出以下错误：

Summative2-test.hs:92:25: error:
    • Couldn't match type ‘[[Atom]]’ with ‘Char’
      Expected type: String
        Actual type: [[[Atom]]]
    • In the expression: map (split' shortGap) (split' mediumGap code)
      In an equation for ‘decodeText’:
          decodeText table code
            = map (split' shortGap) (split' mediumGap code)
   |
92 | decodeText table code=  map (split' shortGap)(split' mediumGap code)
   |                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Failed, one module loaded.

我不明白我在这里哪里犯了错误

我只是想在这个项目的一小部分上寻求帮助

以下是一个例子：

encodeText morseTable "THIS IS A TEST" = [Beep,Beep,Beep,Silence,Silence,Silence,Beep,Silence,Beep,Silence,Beep,Silence,Beep,Silence,Silence,Silence,Beep,Silence,Beep,Silence,Silence,Silence,Beep,Silence,Beep,Silence,Beep,Silence,Silence,Silence,Silence,Silence,Silence,Silence,Beep,Silence,Beep,Silence,Silence,Silence,Beep,Silence,Beep,Silence,Beep,Silence,Silence,Silence,Silence,Silence,Silence,Silence,Beep,Silence,Beep,Beep,Beep,Silence,Silence,Silence,Silence,Silence,Silence,Silence,Beep,Beep,Beep,Silence,Silence,Silence,Beep,Silence,Silence,Silence,Beep,Silence,Beep,Silence,Beep,Silence,Silence,Silence,Beep,Beep,Beep,Silence]

我的计划方法是首先用delimeter

[静默，静默，静默，静默，静默]

拆分

code

这将使：

[[Beep,Beep,Beep,Silence,Silence,Silence,Beep,Silence,Beep,Silence,Beep,Silence,Beep,Silence,Silence,Silence,Beep,Silence,Beep,Silence,Silence,Silence,Beep,Silence,Beep,Silence,Beep],[Silence,Beep,Silence,Beep,Silence,Silence,Silence,Beep,Silence,Beep,Silence,Beep],
[Silence,Beep,Silence,Beep,Beep,Beep],[Silence,Beep,Beep,Beep,Silence,Silence,Silence,Beep,Silence,Silence,Silence,Beep,Silence,Beep,Silence,Beep,Silence,Silence,Silence,Beep,Beep,Beep,Silence]]

然后，我尝试使用

[静默，静默]

作为delimeter来拆分每个列表

[[[Beep,Beep,Beep],[Silence,Beep,Silence,Beep,Silence,Beep,Silence,Beep],[Silence,Beep,Silence,Beep],[Silence,Beep,Silence,Beep,Silence,Beep]],[[Silence,Beep,Silence,Beep],[Silence,Beep,Silence,Beep,Silence,Beep]],
[Silence,Beep,Silence,Beep,Beep,Beep],[[Silence,Beep,Beep,Beep],[Silence,Beep],[Silence,Beep,Silence,Beep,Silence,Beep],[Silence,Beep,Beep,Beep,Silence]]]

此代码已导入：

module Types where

data Atom = Beep | Silence
  deriving (Eq, Show)

type Code = [Atom]

dit, dah, shortGap, mediumGap :: Code
dit       = [Beep, Silence]
dah       = [Beep, Beep, Beep, Silence]
shortGap  = replicate (3-1) Silence
mediumGap = replicate (7-1) Silence

type Table = [(Char, Code)]

morseTable :: Table
morseTable = [ (c , morseCode c) | c <- ['A'..'Z']++['0'..'9'] ]

---

解码文本的正确类型为：

decodeText :: Table -> Code -> [[[Atom]]]
decodeText table code =  map (split' shortGap) (split' mediumGap code)

您编写的类型使用
String
作为返回类型。由于
String
等于
[Char]
，编译器试图使
[[[Atom]]]]]
等于
[Char]
，因此错误
[[Atom]]
与
Char
不匹配。
`
“请为我编写代码”不是一个有效的堆栈溢出问题。我只是在函数的一小部分上寻求帮助。那么，除了那一部分之外，所有问题都无关紧要。
decodeText :: Table -> Code -> [[[Atom]]]
decodeText table code =  map (split' shortGap) (split' mediumGap code)