12 Sep
2003
12 Sep
'03
6:25 p.m.
Alle 00:08, sabato 13 settembre 2003, kuq32tr02@sneakemail.com ha scritto:
ERROR "./mailalias.lhs":5 - Type error in final generator *** Term : map putStrLn strs *** Type : [IO ()] *** Does not match : IO a
Can someone please explain what I'm doing wrong?
This is a type error. You have to "mapM_", not map, see the types in the documentation and try to convince yourself that you need an IO list and not a list of IO, then that you really need an IO () and not an IO list (wich would be returned by mapM). The syntax for a list of t in haskell is [t], in case you didn't notice. V.