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kotlinlang

Is there an unfold equivalent in Kotlin?
F# definition:
```val unfold: 
   generator: 'State -&gt; option&lt;'T * 'State&gt; -&gt;
   state    : 'State 
           -&gt; seq&lt;'T&gt;```

I'm not very familiar with F#. but I guess you're looking for <https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.sequences/generate-sequence.html|generateSequence>

can you be more specific? l - like Tobias - can't read F#. It's too for me foreign to make sense of it.
```val x = 1```
is already a state, but your `unfold` seems way more elaborate.

<@U013AL4M0TF> I'm also not sure what you mean with state? Is it about having the last value available in the lambda for creating the next value? `generateSequence` can do that, just look at the second example on the page I linked above. If you mean something else, please elaborate.

or maybe `sequence` <https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.sequences/sequence.html>

```Unfolding

the opposite of a fold; taking a single value and turning it into a list, or "unfolding" it.```
definititly sounds like generating a sequence to me.

so something like so?
```fun countDown(n: Int) = generateSequence(n) { n -&gt;
  if(n &gt; 0) n-1 else null
}```
