Macro would also be possible, but in that case you would have to require 
the module to use its constants. I agree however that being useable in 
guards is a good point. PRs are always welcome. 

Regarding allowing non-integer values, I do not know if it makes much 
sense. The entire point of defining constants this way is to be able to 
interface with external services/serialization. If you can use Elixir terms 
then you probably do not need this. Or am I missing something?

On Tuesday, August 30, 2016 at 5:14:19 PM UTC+3, OvermindDL1 wrote:
>
> I actually do use a lot of `defmacro something, do: 42` for enums 
> operating with a remote system, this would be convenient.  :-)
>
> Have you thought about making it a macro (be sure to escape the return in 
> case they want the value to be a tuple or so), that way it can be used in 
> more areas and in matching?
>
> On Monday, August 29, 2016 at 11:52:44 PM UTC-6, Michele Balistreri wrote:
>>
>> Hi all,
>>
>> after reading the topic at 
>> http://stackoverflow.com/questions/33851536/how-do-you-define-constants-in-elixir-modules
>>  
>> I decided to use the approach taken by wxErlang. I found this to be a 
>> little verbose, especially since I also needed a list of all constants and 
>> an easy way to convert from the integer value to the associated atom.
>>
>> So I created the const package, which allows you to write this:
>>
>> defmodule Status do
>>   use Const, [:queued, :processed, :sent]
>> end
>>
>> and obtain this
>>
>> defmodule Status do
>>   def queued, do: 0
>>   def processed, do: 1
>>   def sent, do: 2
>>   def all, do: [queued: 0, processed: 1, sent: 2]
>>   def by_value(val) do
>>     # returns the atom from the integer value. In case of duplicated 
>> values, the fist
>>     # associated atom is returned
>>   end
>> end
>>
>> You can also give a keyword list if you need specific values, and even a 
>> list where some elements are just atoms and some are tuples. The behavior 
>> in this case will be like for C enums.
>>
>> More details at: https://github.com/bitgamma/const
>>
>> Hope it can be useful!
>>
>> Regards,
>> Michele Balistreri
>> Bitgamma OÜ
>>
>

-- 
You received this message because you are subscribed to the Google Groups 
"elixir-lang-talk" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to [email protected].
To view this discussion on the web visit 
https://groups.google.com/d/msgid/elixir-lang-talk/9ff0db4b-6181-421d-8ed4-f5da8b5910d4%40googlegroups.com.
For more options, visit https://groups.google.com/d/optout.

Reply via email to