I have yet another question 🙂 Having a flow , I’d like to reduce it (e.g. with + ) and then call a function whenever the reduced flow emitted a new value (or maybe even only if the resulting reduced value changed)

reductions ?

@leonoel yeah that looks promising. reductions also returns a flow does it? How would I consume each item from the flow with a callback function or similar? And could I somehow filter reductions that don’t yield new/different values? (e.g. + 0)

it returns a flow and you may e.g pass it to eduction with dedupe

the callback function can be called in a map or anywhere really

if the business logic is really hairy, you could also consider writing a custom transducer

Gotcha, eduction + dedupe makes sense

And as to map — I would then use eduction with map to trigger the side effect?

yes

Cool. Feels a little strange to do side effects inside map but I guess I can get used to that 😄

in general, user-provided functions are side-effect friendly (`relieve` is the only exception, it can retry). I don't quite follow the cult of purity prevailing in the statically typed FP world 🙂