framework for composing monads?
Sun, 18 Feb 2001 12:59:57 +0100 (CET)
(Moving to haskell cafe...)
On 18-Feb-2001 Manuel M. T. Chakravarty wrote:
>> It is even acceptable for me to manage the state in C -
>> independent of the API design - but then some time there
>> will be the question: Why do I always say that that Haskell
>> is the better programming language, when I'm
>> really doing all the tricky stuff in C?...
> Sure - therefore, I proposed to use `IORef's rather than C
Thanks for the hint!
I took a look at them and now have some questions:
a) It is clear that I need some C-link to access the cli/odbc lib.
Up to now I planned to use Haskell Direct for this. Except of this, I want
to stick to Haskell 98 and seek for maximal portability.
Practically, this raises the question of wether nhc and hbc support hslibs
or else I can provide a substitute for IORef's for these compilers.
Can someone give me hint?
b) What I finally need is "hidden state". My first attempt to get one
using IORefs is:
> import IOExts
> state :: IORef Int
> state = unsafePerformIO $ newIORef 0
> main = seq state $ do
> writeIORef state 1
> currstate <- readIORef state
> putStr (show currstate)
Is this the right way?
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