[Haskell-cafe] records proposals list

Ralf Lammel Ralf.Lammel at microsoft.com
Mon Nov 21 11:49:25 EST 2005


I certainly agree with Keean. It's just that the given example is a bit
misleading. As Bulat observed, the example is about a heterogeneous
list, as opposed to a record. But there are of course tons of record
examples to be found, if you follow the HList link.

Ralf

P.S.: The HList paper also has a reasonable related work section, which
might hold more information of the kind that Bulat asked for.


> -----Original Message-----
> From: haskell-cafe-bounces at haskell.org [mailto:haskell-cafe-
> bounces at haskell.org] On Behalf Of Keean Schupke
> Sent: Monday, November 21, 2005 7:56 AM
> To: Bulat Ziganshin
> Cc: Haskell Cafe
> Subject: Re: [Haskell-cafe] records proposals list
> 
> Hi,
> 
>     Haskell already has static records (in H98)
> 
>     Dynamic records are addressed by the HList library, which uses
> extensions already present in GHC and Hugs (namely Multi-parameter
> type-classes and function-dependancies).
> 
>     So you can do this now... with reasonable syntax, for example to
> create an extensible record
> 
>     ("some thing" .*. (27 :: Int) .*. True .*. HNil)
> 
>     is a statically typed anonymous record.
> 
> 
>     In other words there is no need for any more extensions to GHC or
> Hugs to implement Records (although  having a type-level type-equality
> constaint would simplify the internal implementation of the
library)...
> 
>     For details see the HList paper:
http://homepages.cwi.nl/~ralf/HList/
> 
>     Regards,
>     Keean.
> 
> Bulat Ziganshin wrote:
> 
> >Hello Haskell,
> >
> >  can anyone write at least the list of record proposals for Haskell?
> >or, even better, comment about pros and contras for each proposal?
> >
> >
> >
> 
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