Hi, I am pleased to announce HLint, a tool for making suggestions to improve your Haskell code. Previously this tool was called Dr Haskell and depended on a working installation of Yhc - both of those have now changed. HLint requires GHC 6.10*, and to install simply type: cabal update && cabal install hlint If you haven't yet installed the cabal command, instructions are here: http://ghcmutterings.wordpress.com/2008/11/10/bootstrapping-cabal-install/ As an example of what HLint does, running "hlint darcs-2.1.2" over the latest stable release of darcs gives 385 suggestions, including: darcs-2.1.2\src\CommandLine.lhs:46:1: Use a string literal Found: [' ', '\t', '"', '%'] Why not: " \t\"%" darcs-2.1.2\src\CommandLine.lhs:49:1: Eta reduce Found: quotedArg ftable = between (char '"') (char '"') $ quoteContent ftable Why not: quotedArg = between (char '"') (char '"') . quoteContent darcs-2.1.2\src\CommandLine.lhs:94:1: Use concatMap Found: concat $ map escapeC s Why not: concatMap escapeC s To see all the hints in a nice interactive document visit http://www-users.cs.york.ac.uk/~ndm/hlint/hlint-report.htm (recommended if you are thinking of trying out hlint) All necessary links, including a manual, hackage links, bug tracker and source code can be found from the tool website: http://www-users.cs.york.ac.uk/~ndm/hlint/ Acknowledgements: Niklas Broberg and the haskell-src-exts package have both been very helpful. The darcs users mailing list gave many good suggestions which I've incorportated. Please direct any follow up conversations to haskell-cafe@ Thanks Neil * Why GHC 6.10? View patterns.