[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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