[Haskell-beginners] Equivalent of FOOLANGUAGEPATH environment variable?

[Tom Tobin]

Is there an easy way to declare a particular directory as a location
for finding Haskell modules, similar to PYTHONPATH and similar
environment variables for other languages?  The GHC_PACKAGE_PATH
doesn't seem to be quite the same thing.  There's the option of
setting -iSOMEPATH in one's .ghci file, but that doesn't seem to allow
declaring a relative path via ~ or $HOME, making it a bit of a pain to
maintain separate versions of one's .ghci across different machines.