How to best add logging/debugging code?

[Iavor S. Diatchki]

hello,

Ben Escoto wrote:

>Maybe eventually I will see a need for mapWriter.  As a passing
>thought, I wonder how many programmers can read the mapWriterT
>documentation:
>
>mapWriterT :: (m (a, w) -> n (b, w')) -> WriterT w m a -> WriterT w' n b
>
>and start pounding the code out?  Anyway, once I get this all sorted
>out, I figure my program will have really nice logging, better than
>fprintf(stderr, ...) even.
>  
>
you should not use mapWriterT, usually  you can get the same behaviour 
in a different way
(i think it should not be exported by the module).  by the way once you 
learn how the tranformers work,
you'll be able to guess what that does from its type.  however i think 
it is nice if you can use the transformers
witout knowing how they are implemented.  if you have access to cvs you 
might want to look at
the revamped monad transformer library in  the haskell cvs 
(fptools/libraries/monads). 
it is more docuemnted then the current one, but otherwise it is very 
similar.
bye
iavor








-- 
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| Iavor S. Diatchki, Ph.D. student               | 
| Department of Computer Science and Engineering |
| School of OGI at OHSU                          |
| http://www.cse.ogi.edu/~diatchki               |
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