[Haskell-cafe] How to get Haddock to generate docs for a directory tree of modules

Hi - I've been looking at the docs for Haddock at http://haskell.org/haddock/haddock-html-0.7/index.html but I can't seem to find any option to recursively traverse a directory generating hyperlinked docs for all modules anywhere in the directory or any sub directory etc. Is there a simple undocumented flag I'm missing? Thanks, Brian.