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”

why flatMapMerge/flatMapConcat are not recommended

Who says they’re not recommended? 🤔 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