[Haskell-cafe] Simple Parsec example

What other imports must I add to get this to run. I can't seem to get it right. Michael ========= import Text.ParserCombinators.Parsec.Prim main = case (parse numbers "" "11, 2, 43") of         Left err  -> print err         Right xs  -> print (sum xs) numbers = commaSep integer ============== [michael@sabal ~]$ ghc --make parsetest.hs[1 of 1] Compiling Main             ( parsetest.hs, parsetest.o ) parsetest.hs:7:11: Not in scope: `commaSep' parsetest.hs:7:20: Not in scope: `integer'[michael@sabal ~]$