I agree with both of these comments wholeheartedly. This is why I use with statements prodigiously in my code, but I think OK really shines 
in the builder use case as I mentioned above.
ibgib
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OvermindDL1
- Have you looked at the exceptional library on hex.pm? It includes the functionality of ‘OK’ here as well as more to handle different shapes (handles
:ok/:error2-tuples, however you can integrate in more shape handlers, handles exceptions, handles raw values, and can convert between them all)) and has support for a new error handling paradigm (which I think is ingeniously simple/wonderful, but that is the story for another thread, but it is returning raw values or returning (not raising) exceptions).
For just ‘ok’ 2-tuple handling I think this library handles its purpose wonderfully. 
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Crowdhailer
Creator of Raxx
All interesting points. I’ve run across a some of them but not all.
@brainbag
some of the Elixir functions I needed didn’t return an error tuple.Map.fetch/2for example just returns:error.
This one annoys me the most. I would happily petition away to have this changed to {:error, :not_found} to match convention. In reality if I care enough I just wrap any functions like that.
@brainbag
one of my own functions that returned{:ok, :name, %metadata{}}which wouldn’t fit.
why not create something like response = %{name: :name, meta: %metadata{}. If you have more than one extra thing in the tuple it wouldn’t be clear which is to pass to the next function. and the one that was not passed would be lost for ever.
Interesting point about handling errors out of context which is essential the goal of many error handling strategies.
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Crowdhailer
Creator of Raxx
. I should probably tag a 1.0 release and move on to another project.
Crowdhailer
Creator of Raxx
Just pushed up a possible extension to OK which gives if result blocks inspired by scala for comprehensions.
It allows you to match within the value so you could possibly solve the metadata problem by writing the following.
requires first function to return {:ok, {data, metadata}}
OK.try do
{data, metadata} <- first_function_with_errors
_ <- second_function_with_errors(data)
end
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