RosettaCodeData/Task/SEDOLs/Standard-ML/sedols.ml

27 lines
654 B
Standard ML

fun char2value c =
if List.exists (fn x => x = c) (explode "AEIOU") then raise Fail "no vowels"
else if Char.isDigit c then ord c - ord #"0"
else if Char.isUpper c then ord c - ord #"A" + 10
else raise Match
val sedolweight = [1,3,1,7,3,9]
fun checksum sedol = let
val tmp = ListPair.foldlEq (fn (ch, weight, sum) => sum + char2value ch * weight)
0 (explode sedol, sedolweight)
in
Int.toString ((10 - (tmp mod 10)) mod 10)
end
app (fn sedol => print (sedol ^ checksum sedol ^ "\n"))
[ "710889",
"B0YBKJ",
"406566",
"B0YBLH",
"228276",
"B0YBKL",
"557910",
"B0YBKR",
"585284",
"B0YBKT" ];