import System.Filedata FileErrorioError : String -> FileErrorclassify : Path -> String -> FileErrorreadFile : Path -> Result FileError String with FileReadwriteFile : Path -> String -> Result FileError () with FileWriteappendFile : Path -> String -> Result FileError () with FileWriteexists : Path -> Bool with FileReadisFile : Path -> Bool with FileReadisDir : Path -> Bool with FileReadfileSize : Path -> Result FileError Nat with FileReadreadLines : Path -> Result FileError (List String) with FileReadwriteLines : Path -> List String -> Result FileError () with FileWritereadFileOr : String -> Path -> String with FileReaddata FileError
= NotFound Path
| PermissionDenied Path
| AlreadyExists Path
| NotAFile Path
| IOError StringWhat can go wrong with a file operation.
NotFoundthe path does not exist
PermissionDeniednot allowed to read/write it
AlreadyExistsit already exists (e.g. createDir)
NotAFileexpected a file, found something else
IOErrorany other failure, with a message
ioError : String -> FileErrorA plain IO error from a message (no path), for handle-based operations.
classify : Path -> String -> FileErrorreadFile : Path -> Result FileError String with FileReadRead a whole file as a string. readFile (path "notes.txt") is Ok "<contents>", or Error (NotFound …).
writeFile : Path -> String -> Result FileError () with FileWriteWrite a string to a file, replacing any existing contents.
appendFile : Path -> String -> Result FileError () with FileWriteAppend a string to the end of a file (creating it if needed).
exists : Path -> Bool with FileReadDoes this path exist?
isFile : Path -> Bool with FileReadDoes this path exist and is it a regular file?
isDir : Path -> Bool with FileReadDoes this path exist and is it a directory?
fileSize : Path -> Result FileError Nat with FileReadThe size of a file in bytes.
readLines : Path -> Result FileError (List String) with FileReadRead a file and split it into lines.
writeLines : Path -> List String -> Result FileError () with FileWriteWrite a list of lines to a file, one per line (each followed by a newline).
readFileOr : String -> Path -> String with FileReadRead a file, falling back to a default string if it can't be read. A convenience for when you don't want to handle the error explicitly.