[Haskell-cafe] Fwd: [Haskell] ANN: global-variables-1.0

[Jean-Marie Gaillourdet]

Begin forwarded message:

> From: Jean-Marie Gaillourdet <jmg at gaillourdet.net>
> Subject: Re: [Haskell] ANN: global-variables-1.0
> Date: 12. Oktober 2011 20:27:16 MESZ
> To: Henning Thielemann <lemming at henning-thielemann.de>
> 
> Hi,
> 
> On 12.10.2011, at 20:20, Henning Thielemann wrote:
> 
>> 
>> On Wed, 12 Oct 2011, Jean-Marie Gaillourdet wrote:
>> 
>>> * Simplify the "configuration problem" - at least for code in the
>>> IO monad.
>>> 
>>> Note, that this library does not encourage sloppy software design by
>>> re-introducing all bad effects of global variables.
>> 
>> But isn't this kind of solution for the "configuration problem" an example for sloppy software design? If a global configuration would be passed around, then you could easily use the program functions with different configurations simultaneously. In contrast to that, with the global IORef this is not possible.
> 
> Well, the question whether using a  carefully documented set of global configuration variables which, e.g. only affect the verbosity of logging, is sloppy or not is a question I don't want to answer. But I am convinced there are good reasons to use global-variables *sometimes*. If only for a temporary debugging aid. In any case, an additional possibility to express design intents never hurts. 
> 
> Note, that I wrote "simplify" not solve "the configuration problem"  :-)
> 
> Cheers,
>   Jean