RE: Records in Haskell

2012-01-16 Thread Simon Peyton-Jones
Yitz: very helpful. Can you turn your proposal into a Wiki page? It's different to Johan's. Could you add examples? I don't fully understand your design. | [This has the additional advantage of giving SPJ | motivation to remain engaged, because he seems | to prefer B. :)] True: but that's b

Re: DefaultSignatures and MultiParamTypeClasses

2012-01-16 Thread Reiner Pope
I thought that might be the case. Thanks for that! Cheers, Reiner On 17/01/2012, at 1:15 AM, Simon Peyton-Jones wrote: > | /tmp/Test.hs:4:1: > | The multi-parameter class `C' cannot have generic methods > | In the class declaration for `C' > > Aha. Trawling the commit logs, this tes

Re: Records in Haskell

2012-01-16 Thread Yitzchak Gale
Simon Peyton-Jones wrote: > Johan, if you are serious, do add a new wiki page to > describe the design. > You say it's simple, but I don't think it really is. I'll support Johan by presenting the proposal for A below. I believe that it really is very simple, both in concept and implementation, but

RE: DefaultSignatures and MultiParamTypeClasses

2012-01-16 Thread Simon Peyton-Jones
| /tmp/Test.hs:4:1: | The multi-parameter class `C' cannot have generic methods | In the class declaration for `C' Aha. Trawling the commit logs, this test is simply a vestige of the PREVIOUS generic-class story, now long gone. So we can lift the restriction easily. I'll commit a

Re: DefaultSignatures and MultiParamTypeClasses

2012-01-16 Thread José Pedro Magalhães
Hello Reiner, On Mon, Jan 16, 2012 at 06:32, Reiner Pope wrote: > Hi all, > > I just tried, and it appears that the new DefaultSignatures extension > doesn't work with multi parameter type classes. > > Is there a reason for this restriction, or is it merely an accident? > I don't think the orig

RE: Records in Haskell

2012-01-16 Thread Simon Peyton-Jones
Johan, if you are serious, do add a new wiki page to describe the design. You say it's simple, but I don't think it really is. The whole qualified name story is *already* pretty complicated: see http://ogi.altocumulus.org/~hallgren/hsmod/Description.pdf Particular issues I can think of immedia

RE: Records in Haskell

2012-01-16 Thread Simon Peyton-Jones
| > But note what has happened: we have simply re-invented SORF.  So the | > conclusion is this: | > | >   the only sensible way to implement FDR is using SORF. | | An obvious question at this point: can records have unboxed fields? | I'm worried a bit about the kinds that can appear in a has cons