Welcome to issue 59 of HWN, a weekly newsletter covering developments in the Haskell community.

This week we see the 2007 Haskell Workshop announcement, Haskell.org's participation in the Google Summer of Code gets underway, and of course, new libraries!


Google Summer of Code and Haskell.org. Malcolm Wallace announced that Haskell.org has once again applied to be a mentoring organisation for the Google Summer of Code. If you are a student who would like to earn money hacking in Haskell, or you are a non-student who has a cool idea for a coding project but no time to do it yourself, then visit the SoC wiki to gather ideas, and add yourself to the list of interested people! Add new ideas for projects!

Haskell Workshop Call for Papers. Gabriele Keller announced the initial call for papers for the Haskell Workshop 2007, part of the 2007 International Conference on Functional Programming (ICFP). The purpose of the Haskell Workshop is to discuss experience with Haskell, and possible future developments for the language. The scope of the workshop includes all aspects of the design, semantics, theory, application, implementation, and teaching of Haskell.

Data.CompactString 0.3: Unicode ByteString. Twan van Laarhoven announced version 0.3 of the Data.CompactString library. Data.CompactString is a wrapper around Data.ByteString supporting Unicode strings.

harchive-0.2: backup and restore software in Haskell. David Brown announced release 0.2 of harchive, a program for backing up and restoring data. The package is available from Hackage.

New release of regex packages. Chris Kuklewicz announced new versions of the regex-* packages (base,compat,dfa,parsec,pcre,posix,tdfa,tre). There is a new wiki page with documentation relating to these packages. All packages are available from Hackage, under the Text Category.

StaticDTD: type safe markup combinators from DTDs. Marcel Manthe announced a tool that transforms a Document Type Definition to a library. The resulting library contains combinators that assure proper nesting of elements. The plan is to add more constraints that will also take care of the order of occurrence of children. The parsing of the DTD is done with HaXml. The code is available via darcs.

IPv6 support for network package. Bryan O'Sullivan announced that he'd added IPv6 support to the network package.

Type-level binary arithmetic library. Oleg Kiselyov and Chung-chieh Shan announced a new library for arbitrary precision binary arithmetic over natural kinds. The library supports addition/subtraction, predecessor/successor, multiplication/division, exp2, full comparisons, GCD, and the maximum. At the core of the library are multi-mode ternary relations Add and Mul where any two arguments determine the third. Such relations are especially suitable for specifying static arithmetic constraints on computations. The type-level numerals have no run-time representation; correspondingly, all arithmetic operations are done at compile time and have no effect on run-time.


This section covers the Haskell' standardisation process.


This week's proposals and extensions to the standard libraries.


Avoiding intermediate data structures. David Roundy opened discussion on techniques for avoiding intermediate data structures in Haskell code

Maybe a different Maybe. Joachim Breitner wondered about avoiding intermediate Maybe constructs

Blog noise

Haskell news from the blogosphere.

Quotes of the Week

Code Watch

Tue Mar 6 06:31:12 PST 2007. Simon Marlow. add noDuplicate#. This primop ensures that the current computation is not being duplicated, by calling threadPaused(). The idea is to use it inside unsafePerformIO/unsafeInterleaveIO (see #986).

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