Haskell Weekly News: January 30, 2006

Greetings, and thanks for reading the 22nd issue of HWN, a weekly newsletter for the Haskell community. Each Monday, new editions are posted to the Haskell mailing list and to The Haskell Sequence. RSS is also available.

New Releases

• C-- Frontend. Robert Dockins announced the initial alpha release of a C-- frontend (parser, pretty printer, and semantic checker) written in Haskell. The goal when beginning this project was to create a modular frontend that could be used both by people writing and by those targeting C-- compilers. This implementation attempts to follow the C-- spec as exactly as possible.
• Type level arithmetic. Robert Dockins also released a library for arithmetic on the type level. This library uses a binary representation and can handle numbers at the order of 10^15 (at least). It also contains a test suite to help validate the somewhat unintuitive algorithms.

Haskell'

• Wildcard type annotations
• Reworking the Numeric class
• Partial application ideas
• A more flexible hierarchical module namespace
• Record updates
• On the importance of libraries
• Syntactic support for existentials
• Module system/namespace management
• Fixing the monomorphism restriction
• k patterns
• ~ patterns
• Kind annotations
• Class method types
• A Match class
• Scoped type variables in class instances
• Inline comment syntax

Discussion

• Adding Impredicative Types to GHC. Simon Peyton-Jones pushed a patch into GHC to handle impredicative polymorphism (see Boxy types: type inference for higher-rank types and impredicativity). Secondly, GHC now supports GADTs in the more simplified way described in Simple unification-based type inference for GADTs
• New IO library. Bulat Ziganshin sought information on the low-level IO mechanisms used in GHC's IO libraries, in the context of his work on a high-performance IO lib. Some interesting points relating to IO primitives were raised.

Darcs Corner

Darcs is popular. Isaac Jones brought to our attention the results of the Debian package popularity contest. For the first time a program written in Haskell is more popular than the Haskell toolchain itself. Congratulations to the darcs developers!

Quote of the Week

<araujo> Haskell is bad, it makes you hate other programming languages.

Contributing to HWN

You can help us create new editions of this newsletter. Please see the contributing information, send stories to dons -at- cse.unsw.edu.au. The darcs repository is available at darcs get http://www.cse.unsw.edu.au/~dons/code/hwn