[Haskell-cafe] RFC: Extendable and Easy-To-Use Logger (HLogger)

[Antoine Latter]

On Tue, Apr 12, 2011 at 11:40 AM, Jon Kristensen
<technology at jonkristensen.com> wrote:
> Hello Haskellers!
>
> I have developed a very simple logging library to be extendable and
> easy-to-use. You can see the current release at
> http://hackage.haskell.org/package/hlogger/. The SimpleHLogger module is an
> example of what a HLogger implementation could look like. It could be used
> like this:
>
> import System.Log.SimpleHLogger
>
> main = do
>
>   logger <- simpleLogger "test"
>
>   loggerLog logger (Just ("LoggerTest", "main")) Debug "Test"
>
>   loggerStop logger
>
> As I have now implemented everything that I could think of, I would like to
> ask the Haskell community to give some feedback on HLogger so that I can
> continuing improving it. Some questions:
>

It looks very simple, which is nice.

Just about the only things I would add:

* A standard-out/standard-error logger
* A monoid instance for the Logger type
* Convinience functions for logging without context and logging at a
specific error level:

> logError myLogger "Oh no!"
> logDebug myLogger "a thing happened"

These might be in a separate module, so I can define them for myslef
based on some logContext function, so that in my module I can define:

> logError msg = logContext "Module.Name" LogLevelError msg

You might even be able to offer a separate package with
TemplateHaskell splices to build these helpers. Maybe I'm going off
the deep-end it terms of complexity.


Have you looked into HsLogger at all? This project has a confusingly
similar name - so much so I thought that your email was about
HsLogger!


Take care,
Antoine

> Do you have any general/architectural thoughts on things I might be doing
> wrong?
> Is the ease-of-use goal contradicting making this library useful in more
> complex applications?
> Do I want to redesign HLogger to allow loggers to have a mutable state, and
> if so, how can I do that?
> Is there a nice way to provide the module and the function than using (Just
> ("LoggerTest, "main)) (shortening it somehow, I guess)?
>
> Thanks!
>
> Warm regards,
> Jon Kristensen
>
> _______________________________________________
> Haskell-Cafe mailing list
> Haskell-Cafe at haskell.org
> http://www.haskell.org/mailman/listinfo/haskell-cafe
>
>