unison/unison-src/base58.u
2018-06-27 17:12:17 -04:00

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-- TODO: Characters
-- TODO: Bytes
type Optional a = Some a | None
type Words = Words (Sequence UInt64)
type Integer = Integer
Integer.zero : Integer
Integer.zero = _
shiftLeft : UInt64 -> Integer -> Integer
shiftLeft x y = _
(+) : Integer -> Integer -> Integer
(+) x y = _
unfoldRight : ∀ a b . (a -> Optional (a, b)) -> a -> Sequence b
unfoldRight f z = _
foldLeft : ∀ a b . a -> (a -> b -> a) -> Sequence b -> a
foldLeft z f s = _
toInteger : UInt64 -> Integer
toInteger x = _
bigEndian : Words -> Integer
bigEndian ws = case ws of
Words.Words s ->
foldLeft Integer.zero (acc w -> shiftLeft 8 acc + toInteger w) s
-- TODO: Need some conversions between integers and machine integers
divmod : Integer -> UInt64 -> (Integer, UInt64)
divmod x y = _
(|>) : ∀ a b c . (a -> b) -> (b -> c) -> a -> c
(|>) g f x = f (g x)
(==) : Integer -> UInt64 -> Boolean
(==) a b = _
charAt : UInt64 -> Text -> Text
charAt n = Text.drop n |> Text.take 1
codeString : Text
codeString = "123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz"
base58Encode : Words -> Text
base58Encode ws =
x = bigEndian ws
base58 : Integer -> Optional (Integer, Text)
base58 a =
if a == 0
then Optional.None
else case divmod a 58 of
(d, m) -> Optional.Some (d, charAt m codeString)
foldLeft "" Text.concatenate (unfoldRight base58 x)
base58Decode : Text -> Words
base58Decode txt = _
()