[erlang-questions] eep: multiple patterns

Mats Cronqvist <>
Fri May 16 11:39:19 CEST 2008


Andras Georgy Bekes wrote:
> Hi,
>
> I am trying to end this discussion with some usable result.
>
> First let me state that
> - I am now convinced that ~= is not a good idea, therefore I am not 
> going to submit it in an eep.
> - I am convinced that multiple patterns is a good idea (many of you 
> stated that you like it). I am about to send it as an eep, we just have 
> to agree on the right notation.
>
>   
>> Yes, but Virding's proposal uses ";" for the *SAME* meaning
>> ("or") that it normally has.
>>     
>
> My problem with ; is that it's ambiguous.
> I can write at least one pattern that could be parsed into two different 
> ASTs.
>
>    Pattern when Guard; true ->
> now is this a single pattern: Pattern when (Guard; true) ?
> or is it multiple patterns: (Pattern when Guard); true ?
 i was reading virding's proposal as;

case bla of
  Pat when true ->;
  Pat when false->;
  Pat ->
    code()
end.

  but that's not what he wrote... 

  in that case i propose the above. currently gives syntax error.

  mats




More information about the erlang-questions mailing list