[erlang-questions] Fourth draft of EEP 44 - Additional preprocessor directives

[Michael Truog]

On 10/29/2015 06:08 AM, Björn Gustavsson wrote:
> Here is the fourth draft with more clarifications.
>
> There is also a minor correction in the reference implementation.
>
> http://www.erlang.org/eeps/eep-0044.html
> https://github.com/erlang/eep/blob/master/eeps/eep-0044.md
>
> /Björn
>
It is unclear if these changes will make it into 19.0.  Will any of EEP44 be available?

The is_deprecated/3 described by EEP44 seems unusable due to being focused on Erlang/OTP deprecated functions.  Could we instead implement it with usage of the module_info function so that anyone can easily use is_deprecated/3?  I don't think it requires checking the exports list (if someone is checking an unexported function, that is their problem that they should discover later in their source code).  I have an example implementation below:

is_deprecated(Module, Function, Arity) ->
     Attributes = Module:module_info(attributes),
     lists:any(fun(Attribute) ->
         case Attribute of
             {deprecated, [_ | _] = Deprecated} ->
                 lists:any(fun(Deprecate) ->
                     case Deprecate of
                         {Function, FunctionArity, _}
                             when FunctionArity == Arity;
                                  FunctionArity == '_' ->
                             true;
                         {Function, FunctionArity}
                             when FunctionArity == Arity;
                                  FunctionArity == '_' ->
                             true;
                         _ ->
                             false
                     end
                 end, Deprecated);
             _ ->
                 false
         end
     end, Attributes).