Re: [Haskell-beginners] Expose every Function of a wrapped type

Hi, Have you considered using `Control.Lens.Wrapped` or `Control.Newtype`? You'd have to move the wrapping/unwrapping bits to the sites in your code at which you use underlying `Map` functions (quite repetitive), but it could be easier than redefining all the functions you want (and definitely easier than having to redefine a new one when you think of needing it?). There's probably a canonical way to handle this sort of thing, but I can't find it ATM. Good luck! On Fri, Nov 15, 2019 at 5:00 AM wrote:

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1. Expose every Function of a wrapped type (Leonhard Applis)

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Message: 1 Date: Fri, 15 Nov 2019 11:36:03 +0000 From: Leonhard Applis To: "beginners@haskell.org" Subject: [Haskell-beginners] Expose every Function of a wrapped type Message-ID:

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Hi,

I currently have a newtype definition of a typed Data.Map.

newtype G = G Data.Map String Values

I have done this because for my specific use-case, I can define G as a monoid and get some nice benefits.

However, I find myself often just re-declaring functions of Data.Map and wrap/unwrap them in my Constructor G, such as

singleton :: String -> Value -> G singleton s v = G $ (Data.Map.singleton s v)

I think I do not need to limit the scope of G's functionality, I basically want everything from Data.Map + Bonus , like my Monoid. Also I want G to be a specific Data.Map, there is never any other case where it's not a Map String Values.

However, if I have

type G2 = Data.Map String Values

I cannot instance Monoid.

So, I am very sure that I'm not the first person ever doing this. Is there a language extension providing what I want? Or is what i want "bad"? Am I just missing a higher-order base function which does what I want?

best regards & thanks Leonhard