jrw4 wrote:
I wrote this function as I am just learning Haskell. What it does is it generates a list of all rational numbers between 0 and 1, but I only have it show the first 20.
rationals n :: Integer -> String rationals n = (putStr . unlines . map show) (take n (nub [x % y | y <- [1..], x <- [1..y], x < y]))
Now my problem is the type declaration, the first line. I get the error "Invalid type signature". I googled this error and I was not able to find out why it is giving it to me. I have also tried:
rationals n :: Integer -> [Ratio]
but it gives me the same error.
Please someone point me in the right direction. Thanks.
Just rationals :: Integer -> String suffices. (Without the argument 'n'.) This makes sense, since "rationals" has type Integer. "rationals n" has type String. (But you still cannot declare that in toplevel that way.) Regards, -- Jochem Berndsen | jochem@functor.nl GPG: 0xE6FABFAB