compiler/InterfaceSerialization.hs · elk

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elk/compiler/InterfaceSerialization.hs

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1module InterfaceSerialization ( loadInterface

2 , interfaceDecode

3 , validVersion

4 ) where

6import qualified Data.ByteString.Lazy as L

7import qualified Data.Binary as Binary

9import Paths_Elm (version)

10import Data.Version (showVersion)

11import System.Directory (doesFileExist)

12import System.IO (hPutStrLn, stderr)

13import System.Exit (exitFailure)

15import SourceSyntax.Module

17loadInterface :: FilePath -> IO (Either String L.ByteString)

18loadInterface filePath = do

19 exists <- doesFileExist filePath

20 if exists

21 then do

22 byteString <- L.readFile filePath

23 return $ Right byteString

25 else

26 return $ Left $ "Unable to find file " ++ filePath ++

27 " for deserialization!"

29interfaceDecode :: Binary.Binary a => FilePath -> L.ByteString ->

30 Either String a

31interfaceDecode filePath bytes = do

32 case Binary.decodeOrFail bytes of

33 Left (_, offset, err) -> do

34 Left $ "Got an error, '" ++ err ++ "' at offset " ++

35 show offset ++ " of " ++ filePath ++ ".\n\n" ++

36 "This error may be due to an outdated or corrupt " ++

37 "artifact from a previous build. Please rebuild " ++

38 filePath ++ " and try again."

40 Right (_, _, binaryInfo) -> Right binaryInfo

42validVersion :: FilePath -> (String, ModuleInterface) ->

43 Either String (String, ModuleInterface)

44validVersion filePath (name, interface) =

45 if (iVersion interface) == showVersion version then

46 Right (name, interface)

47 else

48 Left $ "Found build artifacts created by a different " ++

49 "Elm compiler version. Please rebuild " ++

50 filePath ++ " and try again."