RosettaCodeData/Task/SEDOLs/Haskell/sedols.hs

50 lines
1.1 KiB
Haskell

import Data.Char (isAsciiUpper, isDigit, ord)
-------------------------- SEDOLS ------------------------
checkSum :: String -> String
checkSum x =
case traverse sedolValue x of
Right xs -> (show . checkSumFromSedolValues) xs
Left annotated -> annotated
checkSumFromSedolValues :: [Int] -> Int
checkSumFromSedolValues xs =
rem
( 10
- rem
( sum $
zipWith
(*)
[1, 3, 1, 7, 3, 9]
xs
)
10
)
10
sedolValue :: Char -> Either String Int
sedolValue c
| c `elem` "AEIOU" = Left " ← Unexpected vowel."
| isDigit c = Right (ord c - ord '0')
| isAsciiUpper c = Right (ord c - ord 'A' + 10)
--------------------------- TEST -------------------------
main :: IO ()
main =
mapM_
(putStrLn . ((<>) <*> checkSum))
[ "710889",
"B0YBKJ",
"406566",
"B0YBLH",
"228276",
"B0YBKL",
"557910",
"B0YBKR",
"585284",
"B0YBKT",
"BOYBKT", -- Ill formed test case - illegal vowel.
"B00030"
]