in haskell, you can dynamicall add or unload modules in the ghci interactive command prompt.
Load module
Prelude> import Data.Map Prelude Data.Map>
or
Prelude> :m +Data.Map Prelude Data.Map>
or simpliy you can remove the '+' symbol
Prelude> :m Data.Map Prelude Data.Map>
unload module
to unload module, you can simply do the following.
Prelude Data.Map> :m -Data.Map Prelude>