[clean-list] [ standards design ] StdEnv StdList ( instance toString [x] ) -- possibly superfluous behavior

Arjen van Weelden A.vanWeelden at cs.ru.nl
Fri Aug 25 11:20:17 MEST 2006


TK wrote:
> Hey, Arjen!
> 
> 
> 
> 
>     Clean doesn't really
>     support things like `instance toString [Char]', and this definition
>     does
>     get in the way of other toString instances for lists.
> 
> 
> You are right. For instance, I find myself commenting it out from StdEnv.
> 
> 
>     The StdEnv is `set
>     in stone' as to provide backwards compatibility, and it's very difficult
>     to get the CleanTeam to change anything. For instance, making the
>     behavior of take or drop more logical is also not done for this reason. 
> 
> 
> I see :( By the way, You know that saying...
> 
> # /Always go for a change should it bring at least a small improvement! 
> ...seemingly negligible advances accumulate over time bringing rewards 
> //greater //than the cost of any initial change that was made, no matter 
> its scale. However, never change anything just for the sake of it.
> /
> ( http://www.freewebs.com/improving/ )
> 
> In our case, something like a LegacyEnv could be provided. And compiling 
> with a newer version could mean changes to existing code anyway, be it 
> caused by something like a better way of prioritizing type instance 
> selection or just new ways for code optimization which can also rise 
> without syntax changes.
> 
Yes, your right. Still, I have found it next to impossible to get the 
CleanTeam to change the StdEnv.
Another option is to make a NewEnv/NewString that selectively imports 
everything except that instance.

regards,
	Arjen


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