Implementing std.log

[Jens Mueller]

Denis Koroskin wrote:
> On Thu, 21 Apr 2011 01:34:29 +0400, so <so at so.com> wrote:
> 
> >>For me, Logger needs to be simple but feature complete. Here is
> >>my ideal syntax:
> >>
> >>Logger log = new Logger();
> >>log.warn("bewarned");
> >>log.error("error code: %d", 42);
> >>log.fatal("Derp");
> >
> >Fine if you remove the first line, switching the output is
> >something we rarely do, so we shouldn't mandate this for each use.
> >
> >note("just a note :", 5);
> >note!warn("bewarned");
> >note!error(c, ", ", d);
> 
> Having different loggers for different parts of programs (e.g.
> separate logger for my rendering, separate one for audio, separate
> for physics, and so on) is a must for me.
> Because when you debug your code by analyzing log output, you want
> to be able to filter out non-relevant stuff. If you only have ONE
> logger, you will start adding stupid prefixes like this:
> 
> error("GAME/GAMEMODE_CHALLENGE/OBJECTIVE_CHECKER: match data frame
> is not valid");
> 
> instead of
> 
> log.error("match data frame is not valid");

This can be solved by taking the compilation unit into account. I.e.
each logging statement is associated with a file, namely the file it was
used in, i.e. __FILE__. Then one only needs the ability to
disable/enable logging per compilation unit. See e.g. glog's
VLOG/--vmodule on http://google-glog.googlecode.com/svn/trunk/doc/glog.html

Jens