Idris2-boot/libs/base/System/File.idr
2019-06-15 11:54:22 +01:00

135 lines
3.7 KiB
Idris

module System.File
import Data.List
import Data.Strings
public export
data Mode = Read | WriteTruncate | Append | ReadWrite | ReadWriteTruncate | ReadAppend
public export
data FilePtr : Type where
%extern prim__open : String -> String -> Int ->
(1 x : %World) -> IORes (Either Int FilePtr)
%extern prim__close : FilePtr -> (1 x : %World) -> IORes ()
%extern prim__readLine : FilePtr -> (1 x : %World) -> IORes (Either Int String)
%extern prim__writeLine : FilePtr -> String -> (1 x : %World) -> IORes (Either Int ())
%extern prim__eof : FilePtr -> (1 x : %World) -> IORes Int
modeStr : Mode -> String
modeStr Read = "r"
modeStr WriteTruncate = "w"
modeStr Append = "a"
modeStr ReadWrite = "r+"
modeStr ReadWriteTruncate = "w+"
modeStr ReadAppend = "a+"
public export
data FileError = GenericFileError Int -- errno
| FileReadError
| FileWriteError
| FileNotFound
| PermissionDenied
export
Show FileError where
show FileReadError = "File Read Error"
show FileWriteError = "File Write Error"
show FileNotFound = "File Not Found"
show PermissionDenied = "Permission Denied"
show (GenericFileError errno) = "File error: " ++ show errno
toFileError : Int -> FileError
toFileError 1 = FileReadError
toFileError 2 = FileWriteError
toFileError 3 = FileNotFound
toFileError 4 = PermissionDenied
toFileError x = GenericFileError x
fpure : Either Int a -> IO (Either FileError a)
fpure (Left err) = pure (Left (toFileError err))
fpure (Right x) = pure (Right x)
public export
data FileT : Bool -> Type where
FHandle : FilePtr -> FileT bin
public export
File : Type
File = FileT False
public export
BinaryFile : Type
BinaryFile = FileT True
export
openFile : String -> Mode -> IO (Either FileError File)
openFile f m
= do res <- primIO (prim__open f (modeStr m) 0)
fpure (map FHandle res)
export
openBinaryFile : String -> Mode -> IO (Either FileError BinaryFile)
openBinaryFile f m
= do res <- primIO (prim__open f (modeStr m) 1)
fpure (map FHandle res)
export
closeFile : FileT t -> IO ()
closeFile (FHandle f) = primIO (prim__close f)
export
fGetLine : (h : File) -> IO (Either FileError String)
fGetLine (FHandle f)
= do res <- primIO (prim__readLine f)
fpure res
export
fPutStr : (h : File) -> String -> IO (Either FileError ())
fPutStr (FHandle f) str
= do res <- primIO (prim__writeLine f str)
fpure res
export
fPutStrLn : (h : File) -> String -> IO (Either FileError ())
fPutStrLn f str = fPutStr f (str ++ "\n")
export
fEOF : (h : File) -> IO Bool
fEOF (FHandle f)
= do res <- primIO (prim__eof f)
pure (res /= 0)
-- %logging 10
-- read : List String -> File -> IO (Either FileError (List String))
-- read acc h
-- = do eof <- fEOF h
-- if eof
-- then pure (Right (List.reverse acc))
-- else ?whee
-- -- do Right str <- fGetLine h
-- -- | Left err => pure (Left err)
-- -- read (str :: acc) h
-- %logging 0
export
readFile : String -> IO (Either FileError String)
readFile file
= do Right h <- openFile file Read
| Left err => pure (Left err)
Right content <- read [] h
| Left err => do closeFile h
pure (Left err)
closeFile h
pure (Right (fastAppend content))
where
read : List String -> File -> IO (Either FileError (List String))
read acc h
= do eof <- fEOF h
if eof
then pure (Right (reverse acc))
else
do Right str <- fGetLine h
| Left err => pure (Left err)
read (str :: acc) h