Haskell Weekly News: March 06, 2006

Greetings, and thanks for reading issue 27 of HWN, a weekly newsletter covering developments in the Haskell community. Each Monday, new editions are posted to the Haskell mailing list and to The Haskell Sequence. RSS is also available.

Announcements

• Haskell as a markup language. Oleg Kiselyov writes on using Haskell to represent semi-structured documents and the rules of their processing. SXML is embedded directly in Haskell, with an open and extensible set of `tags'. The benefit of this is of course in static type guarantees, such as prohibiting an H1 element to appear in the character content of other elements.

• hmp3 1.0. Don Stewart released hmp3 version 1. hmp3 is a curses-based mp3 player written in Haskell, designed to be fast, small and stable.

• Edison 1.2rc2. Robert Dockins announced the second release candidate for Edison 1.2 is now ready for comments.

Haskell'

• Overlapping instances and constraints
• realToFrac
• instance Functor Set
• Keep the present Haskell record system!
• Relaxed instance rules spec
• Collections
• Partial type signatures/annotations/declarations..
• How to create a proposal

Discussion

• Library Reorganisation. Simon Marlow opened up a discussion on library reorganisation, in the light of the oncoming Haskell'.

• Deprecating FunctorM. Ross Paterson proposes to replace FunctorM with Data.Traversable.

• cabal-setup. Simon Marlow posted a patch to wrap the Setup.hs Cabal script with a generic cabal-setup interface.

Code Watch

• Make -split-objs work with --make.

  Thu Mar  2 09:05:05 PST 2006  Simon Marlow
    * Make -split-objs work with --make
  
    This turned out to be a lot easier than I thought.  Just moving a few
    bits of -split-objs support from the build system into the compiler
    was enough.  The only thing that Cabal needs to do in order to support
    -split-objs now is to pass the names of the split objects rather than
    the monolithic ones to 'ar'.
  

Quotes of the Week

[OConnor's Law]
roconnor :: As an online discussion of static types vs dynamic types grows longer, the 
            probability of mentioning heterogenous lists approaches 1.

[Lemmih's Law]
Lemmih :: Every 18 months, compilers will make their warnings and error messages twice as cryptic

Claus Reinke :: The point about overlapping instances is that they shouldn't.

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