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kotlinlang

*newbi question again*
Well, here I go again…
I found pretty good this blog to understand monads and functors, etc.
<https://medium.com/beingprofessional/understanding-functor-and-monad-with-a-bag-of-peanuts-8fa702b3f69e>
But I am not sure if kotlin `map` 6 `flatMap` is just the same as explained there?

Are you talking about these implementations?
```
def map[B](f: A =&gt; B): Bag[B] = Bag(f(content))
def flatMap[B](f: A =&gt; Bag[B]): Bag[B] = f(content)
```

maybe this can help you I think it still a map from Bag[A] to Bag[B] - <https://stackoverflow.com/questions/18531887/explanation-of-scala-map-function-signature>

Those are in arrow `Functor.map` and `Monad.flatMap`

which have concrete implementations in most data types

Typeclassopedia should be the goto reference for understanding monads and functors.

<@UGYM1LGCX> arrow is a collection of data types (classes) and interfaces (behaviors). One of those behaviors is map, the other is flatMap. That behavior is implemented for most classes, including List, Map, IO, Reader, Observable, NonEmptyList, Function0, Day…tens of them.

<https://github.com/arrow-kt/arrow/blob/master/modules/core/arrow-core-data/src/main/kotlin/arrow/core/Id.kt>

once you are confident with it, move to Option

Option is either Some or None, while NEL is a set of values. That’s one of the classifications of data types, those who grow on alternatives and others that grown on size.