Remove @FlowPreview on (() ->T).asFlow() and (suspend () -> T).asFlow()

[hoc081098]

I notice @FlowPreview has been removed on all extensions ###.asFlow() except () -> T and suspend () -> T. Can we remove it on them?

[qwwdfsad]

We can gradually promote them to experimental.

Our original concern was top-level scope pollution, but it seems like it doesn't bother anyone.

Could you please elaborate on your usages of these extensions?

[martymiller]

We can gradually promote them to experimental.

Our original concern was top-level scope pollution, but it seems like it doesn't bother anyone.

What does this answer mean? Can we remove FlowPreview?

[hoc081098]

Can v1.7 remove it?

[ryanholden8]

Yeah, can we remove it?

[martymiller]

Just wanted to share that I added this to my app level build.gradle.kts (inside of android { })

  tasks.withType<org.jetbrains.kotlin.gradle.tasks.KotlinCompile>().all {
    kotlinOptions.freeCompilerArgs += listOf(
      "-Xopt-in=kotlin.RequiresOptIn",
      "-Xopt-in=kotlin.OptIn",
      "-Xopt-in=kotlinx.coroutines.ExperimentalCoroutinesApi",
      "-Xopt-in=kotlinx.coroutines.ObsoleteCoroutinesApi",
      "-Xopt-in=kotlinx.coroutines.FlowPreview"
    )
  }

This allowed me to remove all the annotations in my code without any complaints or warnings from the IDE. When FlowPreview is eventually removed, I can just remove it from here.

[albertocavalcante]

It's not clear to me, without the compiler flags... can/should it be removed?

[fvasco]

Can someone write some motivation to remove @FlowPreview?
What is the use case?

[JakeWharton]

With annotations like @FlowPreview you actually need to make a justification in the reverse. What is the reason to continue preventing this API from being stable? Ideally every API annotated with it would be revisited at a regular cadence to ensure that each one needs to remain unstable for some valid reason.

[hoc081098]

It is useful to convert a lambda to Flow, without flow { emit(...) }`.

suspend fun fetchApi(): Response

fetcherFlow
  .flatMapLatest { ::fetchApi.asFlow() }
  .collect { ... }

[mhernand40]

It is useful to convert a lambda to Flow, without flow { emit(...) }`.

suspend fun fetchApi(): Response

fetcherFlow
  .flatMapLatest { ::fetchApi.asFlow() }
  .collect { ... }

For this particular snippet, I'd argue that you can use mapLatest which accepts a suspend lambda rather than converting the suspend lambda into a one-shot Flow. 🤷‍♂️

[hoc081098]

@mhernand40 of course, since it is a simple demo. When we use flatMapXXX, we usually transform the input flow to another flow...

suspend fun fetchApi(): Response

fetcherFlow
  .flatMapLatest {
    ::fetchApi.asFlow()
      .map { LCE.Success(it) }
      .onStart { emit(LCE.Loading) }
      .catch { emit(LCE.Error(it)) }
  }
  .collect { ... }