Generic Haskell version 1.42 (Coral) ==================================== We are happy to announce the third release of Generic Haskell, an extension of Haskell that facilitates generic programming. Generic Haskell includes the following features: * type-indexed values -- generic functions that can be instantiated on all Haskell data types. * type-indexed types -- types which are indexed over the type constructors underlying Haskell datatypes. The Generic Haskell compiler takes Generic Haskell source and produces Haskell code. Changes since 1.23 (Beryl) -------------------------- * Dependency-style Generic Haskell [1] is supported, i.e., generic functions can be written in a simpler and more natural style. In particular, type signatures of generic functions have become simpler -- there is no need to define kind-indexed types any longer. * Local redefinition, generic abstraction, and default cases are now implemented as described in "Exploring Generic Haskell" [2]. Download -------- The Generic Haskell compiler is available in source and binary distributions. Binaries for Linux, Windows, and MacOSX are available. These are available from: http://www.generic-haskell.org/compiler.html The documentation is also available separately from that page. For more general information, point your browser to: http://www.generic-haskell.org Why Generic Haskell? -------------------- Software development often consists of designing datatypes, around which functionality is added. Some functionality is datatype specific, whereas other functionality is defined on almost all datatypes in such a way that it depends only on the structure of the datatype. A function that works on many datatypes in this way is called a generic function. Examples of generic functionality include editing, pretty-printing or storing a value in a database, and comparing two values for equality. Since datatypes often change and new datatypes are introduced, we have developed Generic Haskell, an extension of the functional programming language Haskell that supports generic definitions, to save the programmer from (re)writing instances of generic functions. The original design of Generic Haskell is based on work by Ralf Hinze. Pleasant programming, The Generic Haskell Team at Utrecht University info@generic-haskell.org [1] A. Loeh, D. Clarke, and J. Jeuring. Dependency-style Generic Haskell. In O. Shivers, editor, Proceedings of the International Conference on Functional Programming, ICFP'03, pages 141--152. ACM Press, August 2003. [2] A. Loeh. Exploring Generic Haskell. PhD thesis, Utrecht University, September 2004.