I'm having some problem with one of the functions which I'm new at, it's the fromIntegral function.
Basically I need to take in two Int arguments and return the percentage of the numbers but when I run my code, it keeps giving me this error:
Code:
percent :: Int -> Int -> Float
percent x y = 100 * ( a `div` b )
where a = fromIntegral x :: Float
b = fromIntegral y :: Float
Error:
No instance for (Integral Float)
arising from a use of `div'
Possible fix: add an instance declaration for (Integral Float)
In the second argument of `(*)', namely `(a `div` b)'
In the expression: 100 * (a `div` b)
In an equation for `percent':
percent x y
= 100 * (a `div` b)
where
a = fromIntegral x :: Float
b = fromIntegral y :: Float
I read the '98 Haskell prelude and it says there is such a function called fromInt but it never worked so I had to go with this but it's still not working. Help!
Look at the type of div
:
div :: Integral a => a -> a -> a
You cannot transform your input to a Float
and then use div
.
Use (/)
instead:
(/) :: Fractional a => a -> a -> a
The following code works:
percent :: Int -> Int -> Float
percent x y = 100 * ( a / b )
where a = fromIntegral x :: Float
b = fromIntegral y :: Float