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At this point in my learning journey, I simply accepted that this function is called pure (both in Haskell and in PureScript), but it would have helped a lot if I had known the reasoning behind thi...
#1: Initial revision
by
toraritte
·
2024-06-01T12:06:04Z (7 months ago)
Where does the name of the `pure` function in the `Applicative` type class come from?
At this point in my learning journey, I simply accepted that this function is called `pure` (both [in Haskell][1] and [in PureScript][2]), but it would have helped a lot if I had known the reasoning behind this name. Both the Haskell reference and the PureScript docs use the word "_lift_", > <sup>[Haskell][1]</sup> Lift a value into the Structure. > > --- > > <sup>[PureScript][2]</sup> `pure` can be seen as the function which lifts functions of zero arguments but `lift` is already in use (e.g., for monad transformers<sup>[Haskell][3], [Purescript][4]</sup>). The [PureScript reference for `pure`][2] also uses the word "_wrap_", but I understand now why the functor explanations along the lines of "_wrap value in a box_" can be misleading or miss the point entirely. For these reasons, I do like the name `pure` as it has no "baggage" and I can focus on understanding the topic without preconceptions. Books and tutorials using the word "_context_" helped me understand the more abstract constructs, so I sometimes wondered if using "_embed_" would make sense here, but then I let it go. --- Anyway, I still research from time to time to figure out `pure`'s etymology, but did not get any closer yet. [1]: https://hackage.haskell.org/package/base-4.20.0.1/docs/Prelude.html#v:pure [2]: https://pursuit.purescript.org/packages/purescript-prelude/6.0.1/docs/Control.Applicative#t:Applicative [3]: https://hackage.haskell.org/package/transformers-0.6.1.1/docs/Control-Monad-Trans-Class.html#v:lift [4]: https://pursuit.purescript.org/packages/purescript-transformers/6.0.0/docs/Control.Monad.Trans.Class#v:lift