Re: Extensible Records

2007-11-12 Thread Barney Hilken
I've tried to summarise the important differences between the various proposals on the wiki page, but it still needs lots of illustrative examples. Anyone who is interested, please contribute! Barney. ___ Glasgow-haskell-users mailing list Glasgow-

Re: Extensible Records

2007-11-12 Thread Claus Reinke
http://hackage.haskell.org/trac/ghc/wiki/ExtensibleRecords I'm happy to see a Wiki page to summarise and contrast different approaches; that seems like a constructive >thing to do. (Email discussions tend to evaporate and then be repeated.) A useful thing to do would be to >give a series of

RE: Extensible Records

2007-11-12 Thread Simon Peyton-Jones
| There seems to be widespread agreement that the current situation wrt | records is unacceptable, but the official GHC policy is that there are too | many good ideas to choose from - so nothing gets done! I hence humbly | propose that [http://www.cs.uu.nl/~daan/download/papers/scopedlabels.pdf

Re: Extensible Records

2007-11-11 Thread Voldermort
Bulat Ziganshin wrote: > i propose to start "Records project" by composing list of > requirements/applications to fulfill; we can keep it on Wiki page. Wiki page duly created http://hackage.haskell.org/trac/ghc/wiki/ExtensibleRecords ___ Glasgow-haskell

Re: Extensible Records

2007-11-11 Thread Claus Reinke
Hugs.Trex> :t let f opts x = (opt1="default"|opts) in f let {...} in f :: a\opt1 => Rec a -> b -> Rec (opt1 :: [Char] | a) This completely loses the aim of optional arguments: with this type, the argument 'opts' cannot have a field 'opt1' (as shown by the context 'a\opt1'). The type we want

Re: Extensible Records

2007-11-11 Thread Barney Hilken
Hugs.Trex> :t let f opts x = (opt1="default"|opts) in f let {...} in f :: a\opt1 => Rec a -> b -> Rec (opt1 :: [Char] | a) This completely loses the aim of optional arguments: with this type, the argument 'opts' cannot have a field 'opt1' (as shown by the context 'a\opt1'). The type we want

Re: Extensible Records

2007-11-11 Thread Claus Reinke
Whatever system GHC settles on is almost certain to become part of the Haskell standard, and this particular system has some deep limitations which could not be got round without ripping it all out and starting again. i'd like to have "extensible records", but i'd rather like to decompose t

Re: Extensible Records

2007-11-11 Thread Stefan O'Rear
On Sun, Nov 11, 2007 at 03:02:56PM +0300, Bulat Ziganshin wrote: > Hello Barney, > > Sunday, November 11, 2007, 2:34:14 PM, you wrote: > > An important application which is made impossible by this approach is > > i propose to start "Records project" by composing list of > requirements/application

Re: Extensible Records

2007-11-11 Thread Ian Lynagh
On Sat, Nov 10, 2007 at 11:24:24PM +, Voldermort wrote: > > I assume that porting an existing implementation would > be much easier than starting from scratch. I doubt this is true, but even if it is I would prefer to see features chosen based on their merits. (I'm not familiar with the vari

Re: Extensible Records

2007-11-11 Thread Barney Hilken
I think this would be a BIG mistake. Whatever system GHC settles on is almost certain to become part of the Haskell standard, and this particular system has some deep limitations which could not be got round without ripping it all out and starting again. The problem with this (and other "Fl

Re: Extensible Records

2007-11-11 Thread Voldermort
I've entered a feature request for this on Trac http://hackage.haskell.org/trac/ghc/ticket/1866 ___ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users

RE: Extensible Records

2007-11-10 Thread Seth Kurtzberg
I misread it as 6.1. Sorry about that. -Original Message- From: Stefan O'Rear [mailto:[EMAIL PROTECTED] Sent: Saturday, November 10, 2007 6:55 PM To: Seth Kurtzberg Cc: 'Voldermort'; glasgow-haskell-users@haskell.org Subject: Re: Extensible Records On Sat, Nov 10, 200

Re: Extensible Records

2007-11-10 Thread Stefan O'Rear
On Sat, Nov 10, 2007 at 06:35:34PM -0500, Seth Kurtzberg wrote: > Is there any chance of seeing extensible records in GHC 6.10? There seems to > be widespread agreement that the current > situation is unacceptable, but the official GHC policy is that there are too > many good ideas to choose from

Re: Extensible Records

2007-11-10 Thread Stefan O'Rear
On Sat, Nov 10, 2007 at 06:35:34PM -0500, Seth Kurtzberg wrote: > 6.10? I think that's a typo as the current version is 6.8.1. Or did I > misunderstand what you were saying? 6.8.1 is released, there is abolutely no way new features are going to enter a published version. Hence, 6.10. Stefan s

RE: Extensible Records

2007-11-10 Thread Seth Kurtzberg
6.10? I think that's a typo as the current version is 6.8.1. Or did I misunderstand what you were saying? Seth Kurtzberg Software Engineer Specializing in Security, Reliability, and the Hardware/Software Interface -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] O

Re: Re : Extensible records in Haskell

2002-11-07 Thread John Meacham
Are you sure extensible records are needed, I used to really want them until I developed some idioms which seem to replace most needs for them. (1) Haskell Records just plain old haskell records can be used in an extensible fashion quite easily, just provide an alternate to the constructor which f

Re: Re : Extensible records in Haskell

2002-11-07 Thread Nicolas Oury
I just read your proposal for "lightweight extensible records for Haskell" and find it great. But I just wonder : why not keeping both records systems (Haskell 98 and extensible) with their own syntax, introducing for example [{..}] for extensible records for example. This would resolve perform

Re: Re: Extensible records in Haskell

2002-11-07 Thread Keean Schupke
Thanks, have read the paper, however also saw the paper by Simon Peyton-Jones and Mark Jones on Lightweight Extensible Records for Haskell, which I think Simon refered to in an earlier post... would it not be better to have this instead? Regards, Keean Schupke. Alastair Reid wrote: Actu

Re: Re : Extensible records in Haskell

2002-11-07 Thread Adrian Hey
On Wednesday 06 November 2002 10:48 pm, Nicolas Oury wrote: > I am going to try to persuade you: > > * first of all, it seems to be needed in order to make "first class > modules" (cf your paper) . And I think that a true module system would > be useful. But I may be wrong. > > * As far as I am co

Re: Re : Extensible records in Haskell

2002-11-06 Thread Nicolas Oury
t is easy to understand, safe and avoid to rename with different names some fields that should have the same name. * ... I could try find other reasons tomorrow. Simon | -Original Message- | From: Nicolas Oury [mailto:Nicolas.Oury@;ens-lyon.fr] | Sent: 06 November 2002 08:38 | To: [EMAIL P

Re: Re : Extensible records in Haskell

2002-11-06 Thread Alastair Reid
> Just a quick point, which I'm sure you realise, but static typing > gives you guarantees about the runnability of a program that dynamic > typing breaks... Which, presumably, is why he wants T-Rex which gives strong typing and extensible records and comes from the same great source (MP Jones) t

Re: Re : Extensible records in Haskell

2002-11-06 Thread Nicolas.Oury
On Wed, 6 Nov 2002, Keean Schupke wrote: > Just a quick point, which I'm sure you realise, but static typing gives > you guarantees about the runnability of > a program that dynamic typing breaks... You can do almost anything you > would want to use dynamic types for > using a sufficently broad

Re : Extensible records in Haskell

2002-11-06 Thread Keean Schupke
Just a quick point, which I'm sure you realise, but static typing gives you guarantees about the runnability of a program that dynamic typing breaks... You can do almost anything you would want to use dynamic types for using a sufficently broad algebraic data type. For instance you could create

RE: Re : Extensible records in Haskell

2002-11-06 Thread Simon Peyton-Jones
ded otherwise. Simon | -Original Message- | From: Nicolas Oury [mailto:Nicolas.Oury@;ens-lyon.fr] | Sent: 06 November 2002 08:38 | To: [EMAIL PROTECTED] | Subject: Re : Extensible records in Haskell | | > > Hello, is there something like extensible records in ghc? | | >Are you w

Re : Extensible records in Haskell

2002-11-06 Thread Nicolas Oury
> > Hello, is there something like extensible records in ghc? >Are you wanting something like Hugs' T-Rex or did you have something >else in mind? Hello, For what I understand of T-Rex it is what I wait. I need something that can allow to use records without declaring their type first and th

Re: Extensible records in Haskell

2002-11-05 Thread Alastair Reid
> Hello, is there something like extensible records in ghc? Are you wanting something like Hugs' T-Rex or did you have something else in mind? -- Alastair Reid [EMAIL PROTECTED] Reid Consulting (UK) Limited http://www.reid-consulting-uk.ltd.uk/alastair/ ___