mk-update-links.hs

module Main where

import Text.Printf(printf)

pad :: Int -> Char -> String -> String
pad newlength padchar s =
  let extraLength = max 0 (newlength - length s)
      extraChars = take extraLength $ repeat padchar
  in  extraChars ++ s

makeAdress :: (Int, Int) -> Int -> String
makeAdress (startyr, endyr) issue =
  printf "http://hybrida.no/upc/files/updatek/%d-%d/%s-%s.pdf" startyr endyr (mkCompactYrs startyr endyr) (pad 2 '0' (show issue))
  where mkCompactYrs a b = (keep 2 (show a)) ++ (keep 2 (show b))
        keep x s = drop (length s - x) s

includeNext x = (x, x + 1)

adresses :: [String]
adresses = do
  year <- map includeNext [2012, 2014]
  issue <- [0..12]
  return $ makeAdress year issue

main = mapM_ putStrLn adresses