iterateN

[matthewleon]

Create an Unfoldable by repeated application of a function to a seed value.

[JordanMartinez]

Hm... CI is failing because Unfoldable1, which already defines its version of singleton and range, is also exported from the Unfoldable module. So, it exports two members with the same name twice.

Merging this would require a breaking change.

iterateN should be updated to use Unfoldable1 and be re-exported by Unfoldable

[JordanMartinez]

Since Unfoldable1 is a super class of Unfoldable, all types that implement Unfoldable (e.g. Array) also implement Unfoldable1. However, the reverse (e.g. NonEmptyArray) is not the case.

iterateN can be redefined to use Unfoldable1 and get the same behavior. See this gist: https://try.purescript.org/?gist=8b4cd9f94df2189ea0ec15c55309911e

[JordanMartinez]

This also explains why singleton and range are re-exported from Data.Unfoldable1 and do not have a separate definition using Unfoldable.

[JordanMartinez]

🏓 @thomashoneyman

[thomashoneyman]

Is there a reason or precedent for the *N suffix, as opposed to just naming this iterate?

[JordanMartinez]

I think iterateN is similar to Haskell. Consider:

• iterate: https://hoogle.haskell.org/?hoogle=iterate&scope=set%3Astackage
• iterateN: https://hoogle.haskell.org/?hoogle=iterateN&scope=set%3Astackage