[Haskell-beginners] Decent Haskell REPL?

GHCI seems to require type definitions to be described in a separate file and then loaded into the REPL, which is seriously tedious. Are there any Haskell REPLs that don't have such limitations and, preferably, use JIT compilation instead of an interpreter? -- Dr Jon Harrop, Flying Frog Consultancy Ltd. http://www.ffconsultancy.com/?e