How can I make a data structure that essentially just stores a list in Haskell

I have written several functions that operate on a list storing keys and values in the same list, e.g. myList = [k1, v1, k2, v2] but instead of operating on a list, I need to make my own data structure called Translator for my functions to operate on.

Here is one of the functions, it simply checks if a key is in the list. (I am a beginner to Haskell and am not allowed to use any functions I haven't written myself so I know there is probably a lot of room for improvement with this function but that's not what I'm looking for)

hasTranslation _ [] = False  hasTranslation k l = hasTranslation' k l 0  hasTranslation' k l@(x:xs) n                           | n `mod` 2 == 1 && xs == [] = False                           | n `mod` 2 == 1 = hasTranslation' k xs (n+1)                           | k == x = True                           | otherwise = hasTranslation' k xs (n+1)  

I need to make a data structure that stores keys and values of the same type in a list type format and then amend my functions to do this.

I have tried several combinations of type Translator a = [a] and data Translator = IntTranslator [Int] deriving (Show, Eq) though have not been able to wrap my head around how to apply these to how I need them to work.

I should note that my data structure NEEDS to work for keys/values of type Int and String and anything else is a bonus.

Any help greatly appreciated

https://stackoverflow.com/questions/66773666/how-can-i-make-a-data-structure-that-essentially-just-stores-a-list-in-haskell March 24, 2021 at 09:50AM