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 qualified Elm.Internal.Version as Version

10import System.Directory (doesFileExist)

11import System.IO (hPutStrLn, stderr)

12import System.Exit (exitFailure)

14import SourceSyntax.Module

16loadInterface :: FilePath -> IO (Either String L.ByteString)

17loadInterface filePath = do

18 exists <- doesFileExist filePath

19 if exists

20 then do

21 byteString <- L.readFile filePath

22 return $ Right byteString

24 else

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

26 " for deserialization!"

28interfaceDecode :: Binary.Binary a =>

29 FilePath -> L.ByteString -> Either String a

30interfaceDecode filePath bytes = do

31 case Binary.decodeOrFail bytes of

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

34 Left (_, offset, err) ->

35 Left $ concat [ "Error reading build artifact: ", filePath, "\n"

36 , " The exact error was '", err, "' at offset ", show offset, ".\n"

37 , " The file was generated by a previous build and may be outdated or corrupt.\n"

38 , " Please remove the file and try again."

39 ]

41validVersion :: FilePath -> (String, ModuleInterface) ->

42 Either String (String, ModuleInterface)

43validVersion filePath (name, interface) =

44 if iVersion interface == Version.elmVersion then

45 Right (name, interface)

46 else

47 Left $ concat

48 [ "Error reading build artifact: ", filePath, "\n"

49 , " It was generated by a different version of the compiler: "

50 , show (iVersion interface), "\n"

51 , " Please remove the file and try again.\n"

52 ]