Sure, sorry! I’m thinking something like
defmodule Result do
def tap(result, tapper) do
case result do
{:ok, value} = ok ->
tapper.(value)
ok
{:error, _} = error ->
error
end
end
end
# Usage
|> Repo.transaction()
|> Result.tap(fn %{goal: goal} -> PubSub.broadcast_goal_created(user, goal) end)
I realized my earlier message was wrong because i thought you were mapping the current value but it looks you are only interested in “doing something with the value but keeping it as is”? That’s why i named it tap now like in the standard library.
Now this module should be able to handle every data in the shape {:ok, data} | {:error, info} and allow you to run some sideeffects in the case of {:ok, _} via Result.tap/2.
To be honest: If that is now better than your macro? Not really sure. But it’s a function (and definitively very functional, see lots of other languages 
). And also there might be libraries definining something like the Result module for you and it’s a bit more “standard”.
(Also: I wasn’t able to test this code, i hope i didn’t do a really stupid mistake somewhere…)
