• velox_vulnus@lemmy.ml
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    2 months ago

    I’ve read about faux-mutability via use of monads to manage state. Obviously, being a Reddit post and not a well-written article, it does not go into depth about the topic. Would that be performant for a unstable-but-stable quick-sort operation?

    • ☆ Yσɠƚԋσʂ ☆@lemmy.mlOPM
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      2 months ago

      Monads are mostly a popular pattern in Haskell because encapsulating side effects within monads allows the type system to enforce their proper usage. They’re not necessary for immutability or state management in general. It’s just a way to enforce discipline more than anything.

      The way immutability is implemented is using persistent data structures. The idea is that you do structural sharing for the common data when creating changes, so you don’t have to pay the price of a full copy of the data structure. In terms of performance, this approach works pretty well in most cases. It’s more expensive than direct mutation, but far cheaper than a deep copy making it a good compromise for the general case.