Sha256: e031f6086de12c4931a6cd5f9cc5fb7611f686a04ffad5772b2b9b14999ffbf4
Contents?: true
Size: 727 Bytes
Versions: 332
Compression:
Stored size: 727 Bytes
Contents
module Luhn
let private digit c = (int)c - (int)'0'
let private digits number = number.ToString() |> Seq.map digit
let private addend index digit =
if (index % 2 = 0) then digit else
if (digit >= 5) then digit * 2 - 9
else digit * 2
let private addends number =
number
|> List.ofSeq
|> List.rev
|> List.mapi addend
|> List.rev
let private checksum number = (number |> digits |> addends |> List.sum) % 10
let valid (number : string) =
let noSpaces = number.Replace(" ", "")
match Seq.length noSpaces with
| 0 | 1 -> false
| _ ->
match Seq.forall (fun c -> c >= '0' && c <= '9') noSpaces with
| false -> false
| true -> checksum noSpaces = 0
Version data entries
332 entries across 332 versions & 1 rubygems