[Haskell-cafe] Convert IO Int to Int

[Iain Barnett]

On 10 Jun 2009, at 12:55 pm, ptrash wrote:

>
>
> Now I have tried to write a Method which gives me a Number of  
> random numbers
> the same way but it doesn't work.
>
> randomList :: Int -> [Integer]
> randomList 0 = []
> randomList n = do
>                              r <- randomRIO (1, 10)
>                              r:randomList(n-1)
>
> It says   Couldn't match expected type `IO t' against inferred type  
> `[t]'
> r <- randomRIO (1,10) causes an error. But why does it work on the  
> console?
> Is there a way to solve it another way?
>

I had the same problem a while back, the thread is here
http://www.mail-archive.com/haskell-cafe@haskell.org/msg46194.html

the console uses IO already, so it's not a problem there. I ended up  
learning about the >>= operator, and that helped a lot. Anyway, lots  
of helpful links in that mail thread.

Iain