compiler/Build/Interface.hs · elk

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elk/compiler/Build/Interface.hs

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1{-# OPTIONS_GHC -W #-}

2module Build.Interface (load,decode,isValid) where

4import qualified Data.ByteString.Lazy as L

5import qualified Data.Binary as Binary

7import qualified Elm.Internal.Version as Version

8import System.Directory (doesFileExist)

10import SourceSyntax.Module

12load :: FilePath -> IO (Either String L.ByteString)

13load filePath = do

14 exists <- doesFileExist filePath

15 if exists

16 then do

17 byteString <- L.readFile filePath

18 return $ Right byteString

20 else

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

22 " for deserialization!"

24decode :: Binary.Binary a => FilePath -> L.ByteString -> Either String a

25decode filePath bytes =

26 case Binary.decodeOrFail bytes of

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

29 Left (_, offset, err) ->

30 Left $ concat $

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

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

33 , " The file was generated by a previous build and may be outdated or corrupt.\n"

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

35 ]

37isValid :: FilePath -> (String, ModuleInterface) -> Either String (String, ModuleInterface)

38isValid filePath (name, interface) =

39 if iVersion interface == Version.elmVersion

40 then Right (name, interface)

41 else Left $ concat

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

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

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

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

46 ]