Module System

Bulat Ziganshin bulat.ziganshin at
Thu Feb 23 07:26:01 EST 2006

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 at

More information about the Haskell-prime mailing list