[erlang-questions] Line numbers for logging/errors.

[Eider Silva de Oliveira]

I use this:

-define(d(Format, Args),
         io:format("~s" ++ Format,  
[string:left(lists:flatten(io_lib:format("~p~p(~p):", [self(),? 
MODULE, ?LINE])), 35, $ ) | Args])).


On 12/03/2008, at 12:08, Richard Kelsall wrote:

> Nohl Attila Rajmund wrote:
>> Yes, erlang has excellent trace facilities, it shows me that the  
>> 'rfmm'
>> function was called - unfortunately it doesn't show that which of  
>> the 10
>> rfmm functions was called.
>
> Breaking a small subject off the main thread. I haven't written much
> Erlang yet so maybe I'm just missing something, but I get the  
> impression
> Erlang won't tell me the line number when something goes wrong. I feel
> it would be useful to know this and very in keeping with the Erlang
> approach of making bugs nice and visible. So my vote while we're all
> requesting changes to Erlang :) is for more line number visibility.
>
> On a related subject I've played around with the LINE macro to tag
> my own logging/error messages with line numbers and the best I could
> produce was something like this :
>
>   -define(log(Line, Message, Var), log_message(?MODULE, Line, Message,
>           ??Var, Var)).  % LINE macro always gives '1' if I put it  
> here.
>
>   log_message(Module, Line, Message, VarName, Var) ->
>      io:format("log: {~p, ~p} ~s ~s = ~p~n", [Module, Line, Message,
>                VarName, Var]).
>
> and then in my code I can do things like
>
>     ?log(?LINE, "Unexpected post", Other),
>
> This works fine, but it would be nice to just write
>
>     ?log("Unexpected post", Other),
>
> and get the line number somehow. Can this be done?
>
>
> Richard.
>
> _______________________________________________
> erlang-questions mailing list
> erlang-questions@REDACTED
> http://www.erlang.org/mailman/listinfo/erlang-questions