Validate International Securities Identification Number: Difference between revisions
Validate International Securities Identification Number (view source)
Revision as of 13:25, 31 May 2021
, 2 years ago→{{header|Haskell}}: (Tidied)
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Line 1,485:
Or, making alternative choices from the standard libraries:
<lang haskell>import
import qualified Data.
import Data.Maybe (fromMaybe)
-------------------- VALID ISIN STRING -------------------
validISIN, isinPattern, luhn :: String -> Bool▼
validISIN = (&&) . isinPattern <*> (luhn . (show =<<) . stringInts)▼
validISIN :: String -> Bool
validISIN =
(&&) . isinPattern
isinPattern s =
12 == length s
&& all (`elem` capitals) l
&& all (`elem` (capitals ++ digits)) m
&& head r `elem` digits
where
[l, m, r] = bites [2, 9, 1] s
luhn :: String -> Bool
luhn x = 0 == rem (s1 + s2) 10
where
odds = [(: []), const []]
evens = reverse odds
stream f =
stream f = concat $ zipWith ($) (cycle f) (stringInts $ reverse x)▼
concat $
zipWith
($)
(cycle f)
s1 = sum (stream odds)
s2 =
s2 = sum $ sum . stringInts . show . (2 *) <$> stream evens▼
sum $
sum . stringInts . show
charMap :: M.Map Char Int
charMap = M.fromList $ zip (digits
stringInts :: String -> [Int]
Line 1,516 ⟶ 1,531:
bites ns xs =
(reverse . fst) $
foldr
([], xs)
(reverse ns)
capitals, digits :: String
capitals = ['A' .. 'Z']
digits = ['0' .. '9']
--------------------------- TEST -------------------------
main :: IO ()
main =
mapM_
(print . ((,) <*> validISIN))
[ "US0378331005",
]</lang>
{{Out}}
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