I have a function that gets a List and has to return the smallest Element of it.
Unfortunately I keep getting the issue:
Parse error in pattern: minim
What could I have done wrong?
minim :: [Int] -> Int
minim [] = 0
minim [x] = x
minim x:xs = min x (minim xs)
min :: Int -> Int -> Int
min a b
| a > b = b
| a < b = a
If you want to solve it the most Haskell way. I would solve it as such:
-- Does not work for empty lists (so maybe needs to be wrapped in some logic)
foldr1 min [-3,1,2,3]
-- Works for empty but needs a "default value" (in this case 0)
foldr min 0 [-3,1,2,3]
If you want to learn by implementing it yourself, then this works for me
minim :: [Int] -> Int
minim [] = 0
minim [x] = x
minim (x:xs) = min x (minim xs)
min :: Int -> Int -> Int
min a b
| a > b = b
| a < b = a
| a == b = a
I would however make it a bit more safe, because is really 0 the smallest int in the list if it is empty? I think you should use Nothing as the result.
import Data.Maybe
import Prelude hiding (min)
main = print $ minim [1,3,4, 6,6,-9]
minim :: [Int] -> Maybe Int
minim [] = Nothing
minim [x] = Just x
minim (x:xs) = min x <$> minim xs
min :: Int -> Int -> Int
min a b
| a > b = b
| a < b = a
| a == b = a