Return a list of maps in records:get_definition/2

[josevalim]

Today the type signature is:

-spec get_definition(Module :: module(), RecordName :: atom()) ->
                        {create_options(),
                         [{FieldName :: atom(), Default :: dynamic()} | (FieldName :: atom())]}.

However, if in the future, we want to add more properties to fields, the signature above won't support it. My suggestion is for it to return maps with default as an optional field:

                        {create_options(),
                         [#{field := FieldName :: atom(), default => Default :: dynamic()}]}.

Possible new properties could be private fields (only visible with the current module), user metadata, or anything unforeseen. Maybe this will never be added but this should be more forwards compatible.

If you don't beleive this is a good suggestion, feel free to close this issue. :)

[bjorng]

Yes, this is probably a good idea. We don't have time to include it in RC2, but we will consider including it in RC3.

[garazdawi]

I was going to suggest using a native record for it, but as a record cannot have unset fields that is not possible without having to wrap the default key in a tuple or something :(