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haskellcategory-theory

Are List Int and List String the same category in Haskell/Category theory?

Are List Int and List String the same category in Haskell/Category theory?

  • List Int
  • List String

Both are List.

Are they considered the same category?

Thanks.

Solution

  • No -- or rather, mu. Without further details about what you intend the objects and arrows to be, neither of them is a category in the first place.

    What you are probably thinking of is the category Hask, which treats Haskell types as objects and Haskell functions as arrows. In this category, [Int] and [String] are distinct objects, with no (natural, in the non-technical sense of the word) isomorphism between them.