Add Arb.distinct that will terminate

The current distinct is likely to hang if it cannot generate enough unique values. That is why we deprecated it. But the functionality is still useful. I propose we add an alternative, that makes those caveats crystal.

arb.distinct(maxAttempts = 1000, throwOnLimit = true)

Those parameters would not have defaults so it would be obvious what you’re doing.

@myuwono ?

[myuwono]

@aSemy thank you! Quite honestly i was also thinking along similar lines. Because as you’ve rightly highlighted it’s important to have these arbs stateless. Maybe we can introduce such constraint as an additional parameter to checkall.

In a nutshell…

test("my distinct") {
  val myset: MutableSet<B> = mutableSetOf()
  fun isDistinct(a: A, b: B): Boolean = ...
  checkAll(arbA, arbB, constraint = ::isDistinct) { a, b ->
    ...
    
  }
}

I think @aSemy 's idea makes sense.

We have to think about ergonomics but this actually solves a lot of problems, not only distinct.

Wdyt @sksamuel ?

[sksamuel]

Any thoughts on the above ?