Writing a suspend function, and I'm wondering if there's any meaningful difference between these two...

# coroutines

[Joshua Hansen]

Writing a suspend function, and I'm wondering if there's any meaningful difference between these two options. I think either 1) there isn't, or 2) I've got a gap in my understanding of coroutines. For context: transformResultRow() is an expensive operation.
Option 1:

suspend fun transformData(): List<MyData> {
    val results: List<ResultRow> = queryForData() // queryForData() is a suspend fun querying the db

    return withContext(Dispatchers.Default) {
        results.map { resultRow ->
            async {
                transformResultRow(resultRow) // fun transformResultRow(row: ResultRow): MyData
            }
        }.awaitAll()
    }
}

Option 2: (What's the difference? They both seem to be doing the same thing)

suspend fun transformData(): List<MyData> {
    val results: List<ResultRow> = queryForData() // queryForData() is a suspend fun querying the db

    return coroutineScope {
        results.map { resultRow ->
            async(Dispatchers.Default) {
                transformResultRow(resultRow) // fun transformResultRow(row: ResultRow): MyData
            }
        }.awaitAll()
    }
}

[Joshua Hansen]

I found a great answer here:
https://stackoverflow.com/questions/56858624/kotlin-coroutines-what-is-the-difference-between-coroutinescope-and-withcontext

[Joshua Hansen]

It seems that coroutineScope is preferred here conventionally.

[Daniel Pitts]

Yeah, the biggest difference is that you're explicitly setting the dispatcher in the first, where the second one will inherit whatever dispatcher was in scope when the transformData() was called.

[uli]

Is transformResultRow blocking? Or suspend?