Thread

1. snackbroken · 1789450953 · focus · HN ↗

   Map and Filter are nice because they let you reason locally about a single element in isolation. Reduce(Fold) forces you to reason globally about intermediate results. Reduce also forces you to conjure up a "zero" value of the relevant type, which isn't usually difficult but it does constitute some extra mental overhead.

   1. sigbottle · 1789585712 · focus · HN ↗

      Isn't reduce usually used for monoidal operations? Or do people implicitly absue ordering?

      If the algortihm doesn't work the same forward, backwards, and with a tree scan, it ain't reduce (as a first approximation not IFF)

      1. txhwind · 1789609350 · focus · HN ↗

         If the contraint is not in the signature, and cannot trigger a test failure with typical implementation, it doesn't exist.

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