There’s no such a thing as a for loop in Haskell. To apply a function to each element in a list, you can either use map or a list comprehension. Since you already have a list comprehension (which currently does not do anything), let’s just use that: mainfun xs = [helpfun 2 x | x … Read more
The fundamental algorithm is the same as your vertical shift function, since String is also a list of characters, [Char]. You can generalize your algorithm to a move function since the code for moveVer really only requires a list and has no dependency on Img: move :: Int -> [a] -> [a] move n xs … Read more
I think you may be confusing type variables which are used in type annotations, and the actual values being passed to the function. In your definition of mygcd: mygcd c = a + b Unless a and b are defined elsewhere, this will be an error. In other words, these a, b, and c are … Read more
We can start by generating ranges required, and then map count function onto ranges to get list of partial functions, which finally can be applied on the given list. ranges lim n = takeWhile (\(x,y) -> x < lim) [(k*n, (k+1)*n – 1) | k <- [0..]] count (l,r) = length.filter (\x -> l <= … Read more
You can implement it using mapM_/traverse_ or the flipped argument versions: forM_/for_. I prefer for_ since it looks more like the “enhanced for-loop” from languages like Java. import Data.Foldable (for_) myPutStr :: [(Double,String)] -> IO () myPutStr vals = do for_ vals $ \(num, str) -> do putStr str putStr “: ” print (num * … Read more
\p -> square p <= n It’s an unnamed (anonymous) function that accepts variable p, squares it and compares result with n. all (\p -> not $ divideBy p n) testingSlice checks that anonymous function returns true value for each element in testingSlice. Read about lambdas.
It works like a foreach loop, so foreach (x in [1..3]) { foreach (y in [x .. x * 2]) { yield y; } } First x is 1, so y in [1 .. 2] Then x is 2, so y in [2 .. 4] Then x is 3, so y in [3 .. 6] … Read more
I would give you some hints to get you started up: Use filter function to get the odd members of the given list. Cube the resultant list using map function. Find the mean of them by summing the list and dividing it by the length of the list.
Making a guess at what your current code does, here’s a proposal for an algorithm: nondeterministically pick a permutation of the vowels assign indices to the permutation use the standard tails trick to nondeterministically choose the appropriate number of elements from this list In code: import Data.List choose :: Int -> [a] -> [[a]] choose … Read more
You need to transform the input grid into the output grid by mapping a function over each cell of the grid. The mapping function is going to need the coordinates of the cell and the content of the cell. The coordinates are needed to see if the other player fired at that location, and the … Read more