Hello Simon, Thursday, February 23, 2006, 2:21:22 PM, you wrote: SM> ghc --make My.Dotted.Module.hs Main.hs SM> works fine. Similarly with GHCi. i don't known that. we should add this to faq SM> It's only when GHC has to actually *find* a source file for a module SM> that the hierarchical naming convention comes into play. There are two SM> reasons we don't allow the dotted convention: one is simplicity (the SM> description of where GHC looks for files is already a bit complex), and SM> the other is performance - GHC does a lot of looking for interface SM> files, and looking in more places might slow things down (I haven't SM> measureed it, though). 1) ghc's startup speed (before it compiles any module) is good enough at this moment 2) that will slower search only for modules that use this advantage. modules that don't use new naming scheme (including all std library modules) will be found in just the same time -- Best regards, Bulat mailto:Bulat.Ziganshin@gmail.com