shrub/pkg/hs/urbit-atom/lib/Urbit/Atom.hs
2020-01-23 01:45:30 -08:00

62 lines
1.7 KiB
Haskell

{-|
Atom implementation with fast conversions between bytestrings
and atoms.
-}
module Urbit.Atom
( Atom
, atomBytes, bytesAtom
, atomWords, wordsAtom
, utf8Atom, atomUtf8, atomUtf8Exn, atomUtf8Lenient
) where
import Prelude
import Data.ByteString (ByteString)
import Data.Vector.Primitive (Vector)
import GHC.Natural (Natural)
import qualified Data.Text as T
import qualified Data.Text.Encoding as T
import qualified Data.Text.Encoding.Error as T
import qualified Urbit.Atom.Internal as I
--------------------------------------------------------------------------------
type Atom = Natural
--------------------------------------------------------------------------------
-- | Cast an atom to a vector. Does not copy.
atomWords :: Atom Vector Word
atomWords = I.natWords
-- | Cast a vector to an atom. Does not copy unless given a slice.
wordsAtom :: Vector Word Atom
wordsAtom = I.wordsNat
-- | Dump an atom to a bytestring.
atomBytes Atom ByteString
atomBytes = I.pillBytes . I.natPill
-- | Load a bytestring into an atom.
bytesAtom ByteString Atom
bytesAtom = I.pillNat . I.bytesPill
-- | Encode a utf8-encoded atom from text.
utf8Atom T.Text Atom
utf8Atom = bytesAtom . T.encodeUtf8
-- | Interpret an atom as utf8 text.
atomUtf8 Atom Either T.UnicodeException T.Text
atomUtf8 = T.decodeUtf8' . atomBytes
-- | Interpret an atom as utf8 text, throwing an exception on bad unicode.
atomUtf8Exn Atom T.Text
atomUtf8Exn = T.decodeUtf8 . atomBytes
-- | Interpret an atom as utf8 text, replacing bad unicode characters.
atomUtf8Lenient Atom T.Text
atomUtf8Lenient = T.decodeUtf8With T.lenientDecode . atomBytes