[Haskell-beginners] Using GHCi, import submodule that needs to import another submodule?

[James Toll]

Hi,

I am trying to figure out how to import one submodule from a hierarchical module in GHCi.  For example, at the end of Chapter 6 of LYAHFGG (page 106-107), there's an example of a hierarchical module.  Or at the bottom of this page, http://learnyouahaskell.com/modules

If I recreate that module on my system and try to import, this is the output:

[~/Geometry]$ ls
Cube.hs    Cuboid.hs  Sphere.hs
[~/Geometry]$ ghci
GHCi, version 7.6.3: http://www.haskell.org/ghc/  :? for help
Loading package ghc-prim ... linking ... done.
Loading package integer-gmp ... linking ... done.
Loading package base ... linking ... done.
Prelude> import Geometry.Sphere

<no location info>:
    Could not find module `Geometry.Sphere'
    It is not a module in the current program, or in any known package.
Prelude> :set -iGeometry
Prelude> import Geometry.Sphere

<no location info>:
    Could not find module `Geometry.Sphere'
    It is not a module in the current program, or in any known package.
Prelude> :load Sphere
[1 of 1] Compiling Geometry.Sphere  ( Sphere.hs, interpreted )
Ok, modules loaded: Geometry.Sphere.
*Geometry.Sphere> :load Cube

Cube.hs:6:18:
    Could not find module `Geometry.Cuboid'
    Use -v to see a list of the files searched for.
Failed, modules loaded: none.
Prelude> :load Cuboid
[1 of 1] Compiling Geometry.Cuboid  ( Cuboid.hs, interpreted )
Ok, modules loaded: Geometry.Cuboid.
*Geometry.Cuboid> :load Cube

Cube.hs:6:18:
    Could not find module `Geometry.Cuboid'
    Use -v to see a list of the files searched for.
Failed, modules loaded: none.
Prelude> 


So I can't just "import Geometry.Sphere", and I tried setting -i, but that doesn't seem to help.  Instead I have to ":load Sphere".  Fine, but then when I try to ":load Cube", it fails because of the line in Cube.hs that imports Geometry.Cuboid.  Even if I load Geometry.Cuboid first and then try to load Geometry.Cube, it still fails.

So, in GHCi, how do I successfully import a submodule that needs to import some other submodule in the module?

Thanks,


James