Doobie transact over a list of ConnectionIO programs

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Doobie transact over a list of ConnectionIO programs



Let's say I have a list of Doobie programs (all with Unit type parameters, fwiw):


Unit


val progList: List[ConnectionIO[Unit]] = prog1 :: prog2 :: ... :: Nil



Is there any way I can run them in one transaction? A for-comprehension won't work here, because I only know the precise composition of the program list at runtime. Essentially, I suppose I need to fold them together, I guess.



I suppose this question applies to Free Monads in Cats in general, so I'll tag Cats as well. Thanks.





You want to traverse List[ConnectionIO[Unit]] into ConnectionIO[List[Unit]]? If so, that won't work: github.com/tpolecat/doobie/issues/465
– Yuval Itzchakov
2 hours ago




List[ConnectionIO[Unit]]


ConnectionIO[List[Unit]]





@YuvalItzchakov Isn't that ticket about the reverse operation?
– Alvaro Carrasco
9 secs ago




1 Answer
1



You can do that with .sequence from cats:


.sequence


import doobie.implicits._
import cats.implicits

...

val res = progList.sequence // ConnectionIO[List[Unit]]






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