urbit/pkg/king/lib/Noun.hs
2019-08-21 16:49:08 -07:00

51 lines
1.1 KiB
Haskell

module Noun
( module Noun.Atom
, module Data.Word
, module Noun.Conversions
, module Noun.Convert
, module Noun.Core
, module Noun.Cue
, module Noun.Jam
, module Noun.Tank
, module Noun.TH
, _Cue
, LoadErr(..)
, loadFile
) where
import ClassyPrelude
import Control.Lens
import Data.Word
import Noun.Atom
import Noun.Conversions
import Noun.Convert
import Noun.Core
import Noun.Cue
import Noun.Jam
import Noun.Tank
import Noun.TH
--------------------------------------------------------------------------------
_Cue :: Prism' ByteString Noun
_Cue = prism' jamBS (eitherToMaybe . cueBS)
where
eitherToMaybe (Left _) = Nothing
eitherToMaybe (Right x) = Just x
data LoadErr
= FileErr IOException
| CueErr DecodeErr
| ParseErr [Text] Text
deriving (Show)
instance Exception LoadErr
loadFile :: a. FromNoun a => FilePath -> IO (Either LoadErr a)
loadFile pax = try $ do
byt <- try (readFile pax) >>= either (throwIO . FileErr) pure
non <- cueBS byt & either (throwIO . CueErr) pure
res <- fromNounErr non & either (throwIO . uncurry ParseErr) pure
pure res