[Haskell-cafe] Re: The state of Hugs

[wren ng thornton]

Ketil Malde wrote:
> wren ng thornton <wren at freegeek.org> writes:
> 
>>> A bit more seriously: is there any listing anywhere of which extensions
>>> Hugs supports?
> 
>> Cabal has a partial listing embedded in its code, though I can't seem
>> to find a textual version at the moment. In general, Hugs has all the
>> features of GHC 6.6: FFI, CPP, MPTCs, FunDeps,
>> OverlappingInstances,... I'm forgetting off-hand whether it has
>> Rank2Types/RankNTypes, but I think so.

Indeed Rank2Types are supported.


>> Of course, since it's GHC6.6-era that means it doesn't support
>> LANGUAGE pragma to enable these features.
> 
> I'm not entirely up to speed on Hugs nor Haskell 2010, but it seems that
> it's fairly close to compliance?  

Well here's the list of accepted proposals for 2010:

http://hackage.haskell.org/trac/haskell-prime/query?state=accepted&milestone=Haskell+2010

So far these ones are already implemented:

     HierarchicalModules
     FixityResolution
     ForeignFunctionInterface
     RelaxedDependencyAnalysis

Which leaves the following (seemingly simple) syntactic changes:

     DoAndIfThenElse
     LineCommentSyntax
     NoNPlusKPatterns

And the following more significant changes:

     EmptyDataDeclarations
     PatternGuards
     LanguagePragma

How significant these last three actually are would depend on the code 
base. They shouldn't be too difficult I wouldn't think, but then I don't 
know much about Hugs' code nor what sorts of implementation details the 
extensions might run into.

-- 
Live well,
~wren