ghc --make would be wonderful for UniForM, which at the moment consists of a large selection of libraries, were it not for the restriction that ghc --make insists on only having one module as an argument. Er why? At this rate I shall be driven to writing an otherwise useless module which imports all the modules in each directory, since ghc --make does indeed look a lot faster than compiling each module individually. (In particular, we win big here, I think because the NFS system is very inefficient and makes reading all the .hi files very expensive.)
Actually I'd like to just give ghc --make a list of ALL the source files and let it figure out the dependencies. This could also include object files (compiled from C) which were to be linked in, for example.
It's something we'd like to do, but haven't got around to yet. Perhaps for 5.01. Cheers, Simon