Well, here is your problem:
map :: (a -> b) -> [a] -> [b]
putStrLn :: String -> IO ()
qlist :: [String]
map putStrLn :: [String] -> [IO ()]
map putStrLn qlist :: [IO ()]
The type of (map putStrLn qlist) is not of the form IO a, so it's not
an action which can be run. There are some useful prelude
I have a simple list like this:
qlist = ["ll", "kkk", "d"]
Why is it OK to do this:
qwrap [] = putStrLn ":"
qwrap (a:as) = do
putStrLn a
qwrap as
qwap qlist
but not this:
map putStrLn qlist
What is going on in the map function?
McQueen
__
Keean Schupke wrote:
Well, I'll put my hand up, I use Haskell with databases and web
stuff... Unfortunately when I started the common tools were not
available. I have a home-grown Haskell-Servlet server, with monadic
continuation based HTML composition and a HaskellDB like database
layer. It
Bayley, Alistair wrote:
From: Brian Strand [mailto:[EMAIL PROTECTED]
So far Takusen is working great (once I figured out the
proper incantations
for getting "select * from dual" working, things went much
faster...). We
don't currently use LOBs, and very rarely call stored
procedures, so th
Well, I'll put my hand up, I use Haskell with databases and web stuff...
Unfortunately when I started the common tools were not available. I have
a home-grown Haskell-Servlet server, with monadic continuation based
HTML composition and a HaskellDB like database layer. It all works very
well, bu
> From: Brian Strand [mailto:[EMAIL PROTECTED]
>
> So far Takusen is working great (once I figured out the
> proper incantations
> for getting "select * from dual" working, things went much
> faster...). We
> don't currently use LOBs, and very rarely call stored
> procedures, so there's a
John Goerzen wrote:
On 2005-08-18, Brian Strand <[EMAIL PROTECTED]> wrote:
I'm thinking about (re)writing some perl code in Haskell (for performance and
correctness reasons). Has anyone done much with Oracle and Haskell? So far
Not Oracle specifically, but other databases, both free and pro
Bayley, Alistair wrote:
From: Brian Strand [mailto:[EMAIL PROTECTED]
I've gotten takusen
(http://cvs.sf.net/viewcvs.py/haskell-libs/libs/takusen/)
to compile and run on my Suse 9.3 x86-64 box against Oracle
10.1.
Cool. I'm keen for feedback. I can also give general advice as far as
interfac
