Sha256: 474c79df261c738e28e612aa4c620842e11c13f79b33fed1098000ac77d14676
Contents?: true
Size: 816 Bytes
Versions: 159
Compression:
Stored size: 816 Bytes
Contents
fun rebase (inBase, digits, outBase) = let
fun fromBase base = let
fun f (x, NONE ) = NONE
| f (x, SOME n) =
if x >= 0 andalso x < base then SOME(n * base + x)
else NONE
in
foldl f (SOME 0)
end
fun toBase base = let
infix divMod
fun a divMod b = (a div b, a mod b)
fun swap (a, b) = (b, a)
fun unfold f b =
case f b of
SOME(a, b') => a :: unfold f b'
| NONE => []
fun f 0 = NONE
| f x = SOME (swap (x divMod base))
in
rev o (unfold f)
end
in
if inBase < 2
orelse outBase < 2
orelse (List.length digits) = 0
orelse (List.length digits) = (List.length (List.filter (fn x => x = 0) digits))
then NONE
else case fromBase inBase digits of
SOME v => SOME (toBase outBase v)
| NONE => NONE
end
Version data entries
159 entries across 159 versions & 1 rubygems