Logging function name, line, file...

[Bruno Medeiros]

Bill Baxter wrote:
> Bruno Medeiros wrote:
>> Jaro wrote:
>>> Is it possible to log file name, line, and function name in D like it 
>>> was in C++ when we could hide __FILE__, __LINE__, __FUNCTION__ in a 
>>> new logging macro? That way this information was printed in log file, 
>>> and was extremely useful.
>>
>> You can use mixins to achieve that. Not as direct as C++ macros, but 
>> it's the cleanest you get:
>>
>> -----  -----
>> import std.stdio;
>> import std.string;
>>
>>
>> void log(string msg) {
>>     writefln("LOG: " ~ msg);
>> }
>>
>> string logm(string msg) {
>>     return `log(__FILE__ ~":"~ toString(__LINE__) ~ " `~msg~`");`;
>> }
>>
>> void main()
>> {
>>      mixin(logm("entering main!"));
>>     auto numbers = [4, 8, 15, 16, 23, 42];
>>     mixin(logm("exiting main!"));
>> }
>>
>> -----  -----
>> Outputs:
>>
>> LOG: src\test.d:15 entering main!
>> LOG: src\test.d:17 exiting main!
>>
>> Is this what you intended?
>>
> 
> 
> Maybe this should go in a FAQ before it gets asked & answered another 5 
> times?
> 
> --bb

Guess so, if the FAQ is easily accessible and people remember to check it.

Out of curiosity, where has this been asked before? I do remember seeing 
it asked before and people mentioning mixins as well, and I tried 
searching for such posts before posting this one, but I didn't find 
anything.


-- 
Bruno Medeiros - MSc in CS/E student
http://www.prowiki.org/wiki4d/wiki.cgi?BrunoMedeiros#D