Hello Jean-Philippe, Sunday, October 23, 2005, 7:19:18 PM, you wrote: JPB> http://haskell.org/hawiki/StandardCollectionLibraries i propose the following plan of actions: 1) define list of datastructures which will be included in this infrastructure 2) knowing 1) we can define class hierarchy and list of functions in each class 3) knowing 2) we can define our qiuckcheck and performance tests 4) now we can go to rewrite our modules one more question: standard Haskell98 libraries has two different interfaces for collections - one in Data.List and fully different for arrays. it is likely that we will use List-like interface? btw, are you seen our PackedStrings debates? as part of this project Simon Marlow actually implemented List-like interface to unboxed immutable arrays :) -- Best regards, Bulat mailto:bulatz@HotPOP.com