Sha256: 7baf495af0718c2f23da45b02d5c5e1dc51a49638562d85405c9e225c05febf4
Contents?: true
Size: 705 Bytes
Versions: 64
Compression:
Stored size: 705 Bytes
Contents
module Luhn
let digit c = (int)c - (int)'0'
let digits number = number.ToString() |> Seq.map digit
let addend index digit =
if (index % 2 = 0) then digit else
if (digit >= 5) then digit * 2 - 9
else digit * 2
let checkDigit (number:int64) = number % 10L
let addends (number:int64) =
number
|> digits
|> List.ofSeq
|> List.rev
|> List.mapi addend
|> List.rev
let checksum (number:int64) = (number |> addends |> List.sum) % 10
let valid (number:int64) = checksum number = 0
let create (target:int64) =
let targetNumber = target * 10L
if valid targetNumber then targetNumber
else targetNumber + 10L - (int64)(checksum targetNumber)
Version data entries
64 entries across 64 versions & 1 rubygems