Based on our discussion here and to create some kind of guide for new players..

What are your guidelines and recommendations on method signatures and return values?

Since everyone can get creative in a dynamic language like Elixir you probably have some guidelines in your companies on how to define new methods and what should they return so you have easier code transfers from one programmer to another.

For example:

• How many parameters is too much for a function? When do you rather create a structure to contain the incoming data?

• Do you rather use single parameters or do you prefer receiving a map that you map and deconstruct?

• What is your ordering of parameters? Do you put the most static parameters to front or back?

• Do you override methods with specific mappings or rather have one method with a case inside?

• What do you return from methods? Are there methods that are returning just plain values in your projects and when do you switch to {:ok, data…} tuples?

• Do you return {:ok} or just plain :ok? For me {:ok} is more consistent with {:ok, data}, for others it’s not.

• How many return values do you put in your return statements? Just one or two? For example, {:ok, data}, {:ok, data1, data2}

• When do you create a return structure?

More questions will come from the discussion.