compiler/InterfaceSerialization.hs · elk

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elk/compiler/InterfaceSerialization.hs

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1{-# OPTIONS_GHC -W #-}

2module InterfaceSerialization ( loadInterface

3 , interfaceDecode

4 , validVersion

5 ) where

7import qualified Data.ByteString.Lazy as L

8import qualified Data.Binary as Binary

10import qualified Elm.Internal.Version as Version

11import System.Directory (doesFileExist)

13import SourceSyntax.Module

15loadInterface :: FilePath -> IO (Either String L.ByteString)

16loadInterface filePath = do

17 exists <- doesFileExist filePath

18 if exists

19 then do

20 byteString <- L.readFile filePath

21 return $ Right byteString

23 else

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

25 " for deserialization!"

27interfaceDecode :: Binary.Binary a =>

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

29interfaceDecode filePath bytes = do

30 case Binary.decodeOrFail bytes of

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

33 Left (_, offset, err) ->

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

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

36 , " The file was generated by a previous build and may be outdated or corrupt.\n"

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

38 ]

40validVersion :: FilePath -> (String, ModuleInterface) ->

41 Either String (String, ModuleInterface)

42validVersion filePath (name, interface) =

43 if iVersion interface == Version.elmVersion then

44 Right (name, interface)

45 else

46 Left $ concat

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

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

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

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

51 ]