That’s cool, I’ve never considered that before.
sodapopcan
sodapopcan
It depends on how structured you want it. Use defstruct for domain entities for sure (ecto returns structs). You general want a struct when you have specific behaviour associated with them which you define in the same module (which makes it feel a little like OO without the state encapsulation). I actually don’t have a great example of when to use bare maps but maybe someone else does? If I don’t care about well structured data, I just simple tuples. I’m also on my phone right now so it’s annoying to type out code 
0
kasvith
I think you have not fully understood what I was looking for.
Yes I’ve read the guide and I know the Let It Crash philosophy.
In The guide, it talks about something completely different than what we were discussing above. I know about try/catch/rescue, just wanted to get some opinions about how to represent errors in a scalable manner and a standard way(currently suggestion is to use {:error, exeception} tuples)
0
sodapopcan
cjbottaro
method signatures
You have been banned from ElixirForum. Hehe, jk.
Function returns are tricky, especially when using with imo. I usually end up making wrapper functions…
defmodule Foo do
def call(config) do
with {:ok, var} <- System.fetch_env("FOO"),
{:ok, blah} <- Keyword.fetch(config, "BLAH")
do
do_something_with(var, blah)
else
:error -> "htf do I know which one failed??"
end
end
end
With wrappers…
defmodule Foo do
def call(config) do
with {:ok, var} <- fetch_env_foo()
{:ok, blah} <- fetch_config_blah()
do
do_something_with(var, blah)
else
{:error, :fetch_env_foo} -> handle_fetch_env_foo_error()
{:error, :fetch_config_blah} -> handle_fetch_config_blah_error()
end
end
defp fetch_env_foo do
case System.fetch_env("FOO") do
:error -> {:error, :fetch_env_foo}
ok -> ok
end
end
defp fetch_config_blah do
case Keyword.fetch(config, "BLAH") do
:error -> {:error, :fetch_config_blah}
ok -> ok
end
end
end
Curious what other people think about this.
0
OndrejValenta
Aren’t you missing : there?
I might do it this way, just so I need just one branch to handle all missing envvars. I’m not that happy that it’s just plain tuple, map could be better, not sure about that..
:error -> {:error, {:fetch_env, "FOO"}}
0
cmo
If the errors matter and I’m handling them in the function, I use nested case statements. If I don’t care about the error I use a with. If I want to return an error sometimes I’ll return an exception struct.
Not a fan of tagged tuples. Put them in the bin 
0
benwilson512
Author of Craft GraphQL APIs in Elixir with Absinthe
cmo
Sorry, that was a bit vague. I am not a fan of creating tagged tuples in a with statement for the sole purpose of matching on them in the else clause.
I’m all for ok/error tuples 
1