Hi,

Christophe Raffalli wrote:
> --------------------------------
> let f b l = match l with
>   [] | [_] -> 1
> | [a;_] | [_;a] when a = b-> 2
> | _ -> 3
> 
> let _ =
>   print_int (f 1 [1;2]);
>   print_int (f 1 [2;1]);
>   print_newline ()
> --------------------------------
> 
> Do you think this code should have a useless pattern warning and print
> "23" instead of "22" ?
> 
> If someone tell me this is a bug then I fill a bug report ...

I guess that the priorities says that you should "read" the third line as

| [a;_] | ( [_;a] when a = b ) -> 2

This would justify the warning and explain the behaviour...

Cheers,

Samuel.