I m trying my hand at Euler Problem 4 in Haskell. It asks for that largest palindrome formed by multiplying two three-digit numbers. The problem was simple enough, and I thought my Haskell-fu was up ...

Can anybody explain how does foldr work? Take these examples: Prelude> foldr (-) 54 [10, 11] 53 Prelude> foldr (x y -> (x+y)/2) 54 [12, 4, 10, 6] 12.0 I am confused about these executions....

How can I efficiently implement a list data structure where I can have 2 views to the head and end of the list, that always point to a head a tail of a list without expensive calls to reverse. i.e: ...

I am doing problem 61 at project Euler and came up with the following code (to test the case they give): p3 n = n*(n+1) `div` 2 p4 n = n*n p5 n = n*(3*n -1) `div` 2 p6 n = n*(2*n -1) p7 n = n*(5*n -3)...

I ve just started learning about Functional Programming, using Haskel. I m slowly getting through Erik Meijer s lectures on Channel 9 (I ve watched the first 4 so far) and in the 4th video Erik ...

The type of the Prelude function flip is: flip :: (a -> b -> c) -> b -> a -> c I.e., it takes one binary function and two arguments. The type of the Prelude function id is: id :: a -...

group :: Ord a => [(a, [b])] -> [(a, [b])] I want to look up all pairs that have the same fst, and merge them, by appending all the list of bs together where they have the same a and discarding ...

I want to do a popen() / python s subprocess.communicate from Haskell - start a program, give it stdin, and get its stdout/stderr. What s the most direct / Haskellish way to do this?