[Haskell-cafe] Useful IDE features -

[peterv]

> (which just states that record type and field label type together uniquely
determine the field value type)

That's nice. When will a new Haskell standard become official? It seems so
many new extensions exist, that one cannot judge the language by looking at
"Haskell98" anymore.

> in practice, overloading introduces overhead that might hamper
performance.

You mean overloading in general, so using type classes? Is this comparable
to the Java/C#/C++ overhead with virtual methods, so one extra level of
indirection before the function gets called? Or is it much worse?

-----Original Message-----
From: haskell-cafe-bounces at haskell.org
[mailto:haskell-cafe-bounces at haskell.org] On Behalf Of Claus Reinke
Sent: Wednesday, June 20, 2007 01:28
To: haskell-cafe at haskell.org
Subject: Re: [Haskell-cafe] Useful IDE features - 

> That looks nice, just unfortunate you need to cast to ::Float in
homer2?Age::Float. I don't see 
> why this is needed, but I must say I don't understand your code completely
yet, working on that :)

that annotation is not needed if you keep the functional dependency
(which just states that record type and field label type together uniquely
 determine the field value type)

>>class Has field value record | field record -> value where
>>    (?)  :: record -> field -> value
>>    (<:) :: (field,value) -> record -> record

> Also, wouldn't this approach be less performant? Or is GHC that good that
ist compiles away all 
> the overhead?

in principle, there is no need for this to be less performant.
in practice, overloading introduces overhead that might hamper
performance.

claus

_______________________________________________
Haskell-Cafe mailing list
Haskell-Cafe at haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe

No virus found in this incoming message.
Checked by AVG Free Edition. 
Version: 7.5.472 / Virus Database: 269.9.1/854 - Release Date: 19/06/2007
13:12
 

No virus found in this outgoing message.
Checked by AVG Free Edition. 
Version: 7.5.472 / Virus Database: 269.9.1/854 - Release Date: 19/06/2007
13:12