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 =>

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

31interfaceDecode filePath bytes = do

32 case Binary.decodeOrFail bytes of

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

35 Left (_, offset, err) ->

36 Left $ concat [ "Got an error, '" ++ err ++ "' at offset "

37 , show offset ++ " of " ++ filePath ++ ".\n\n"

38 , "This error may be due to an outdated or corrupt "

39 , "artifact from a previous build. Please rebuild "

40 , filePath ++ " and try again."

41 ]

43validVersion :: FilePath -> (String, ModuleInterface) ->

44 Either String (String, ModuleInterface)

45validVersion filePath (name, interface) =

46 if iVersion interface == showVersion version then

47 Right (name, interface)

48 else

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

50 "Elm compiler version. Please rebuild " ++

51 filePath ++ " and try again."