RosettaCodeData/Task/Truncatable-primes/Haskell/truncatable-primes-3.hs
Ingy döt Net 68f8f3e56b all tasks
2013-04-11 01:07:29 -07:00

8 lines
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Haskell

digits = [1..9] :: [Integer]
smallPrimes = filter isPrime digits
pow10 = iterate (*10) 1
mul10 = (pow10!!). length. show
righT = (+) . (10 *)
lefT = liftM2 (.) (+) ((*) . mul10)
primesTruncatable f = iterate (concatMap (filter isPrime.flip map digits. f)) smallPrimes