Monad instance for EvalOption[A] in Scala

Asked Mar 03 '23 at 18:53

Active Mar 04 '23 at 02:18

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Imagine an EvalOption type defined as follows:

type EvalOption = [A] =>> Eval[Option[A]]

Is it possible to create an instance of Monad in such a way that the stack safety of Eval is maintained?

I was able to create an Applicative instance for such type, but I'm having problems implementing the flatMap method. So, if anyone knows way of doing this I would be very grateful .

Thanks, have a nice one!

asked Mar 03 '23 at 18:53

Gabriel Santana Paredes

1

That would just be `OptionT` wouldn't it? – Luis Miguel Mejía Suárez Mar 03 '23 at 21:27
@LuisMiguelMejíaSuárez Indeed! That's what I had in mind, but I wanted to see how it could be implemented without using monad transformers. However, if I can't find a way to implement it, I will definitely use your solution, thank you very much! – Gabriel Santana Paredes Mar 03 '23 at 21:58
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Well you can check how `OptionT` works, you basically have to `flatMap` and then `match` – Luis Miguel Mejía Suárez Mar 03 '23 at 22:23

Monad instance for EvalOption[A] in Scala

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