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kotlinlang

Hi! Is there any blog post/other that explains why flatMapMerge/flatMapConcat are not recommended? It says “most likely, suspending operations in map will be sufficient”, but that doesn't explain how to handle “I have a Flow, and I want to map each element to another flow”

&gt;  why flatMapMerge/flatMapConcat are not recommended
Who says they’re not recommended? :thinking_face: Perhaps they meant that they’re often not exactly what you want: if you use `flatMapMerge`, then all of the flows you emitted are active at the same time, and their emissions are merged.
That is if you have `fn(x) = flowOf(x1, x2, x3, …)` and do `flow.flatMapMerge { fn(it) }` then if `flow` emits `a, b, c, d, e` then after flat map you’l be getting `a1, b1, a2, c1, c2, b2, a3, b3` etc. Previously emitted flows don’t get cancelled

With `flatMapConcat`, the all the flows you emit wait until the previous one _finishes._

So it’s just that their use cases are pretty rare and most of the time when converting an element to flow you’d want use `flatMapLatest`, because you’d not be interested in items emitted from flows created for previous value than the latest