Aside from the issue of no-file-means-nil vs no-file-means-object there is an interestingly tricky thing in that FileMan more explicitly splits file entry objects and directory entry objects. Squeak uses DirectoryEntry and makes an instance of a suitable subclass (which is one of the things making no-file-means-object tricky you can't make the right thing if it isn't there to check) whereas FileMan exposes #asDirectoryEntry such that it makes an object that only works for directories, and a asFileEntry similar for files.
All of which is making it hard to think of nice clean ways to make trunk code that will keep working properly if FileMan is installed.
tim -- tim Rowledge; tim@rowledge.org; http://www.rowledge.org/tim Strange OpCodes: CWB: Carry With Borrow