I use GHC 5.00.2 on Solaris 2.6 at the university and am unable to use hierarchical module names --- with and without the -fglasgow-exts switch. GHCi notifies me of parse errors on the module name. What is interesting is that if my module with hierarchical name imports a module which cannot be found GHC tells me that it cannot find the latter module instead of first recognizing that the name of the former module is in its opinion illegal and complaining about this. Aren't hierarchical module names supported yet in GHC 5.00.2? At home with GHC 5.02 under Linux everything works fine. By the way, I couldn't find anything about hierarchical module names in the documentation.

5.00.2 didn't support hierarchical module names, but 5.02 does have the extension. We're not making a lot of noise about it right now because the full switchover is slated for the 5.04 release, when we'll move all the libraries over to use the hierarchical module system. Cheers, Simon