//@NO-IMPLICIT-PRELUDE
//! Functions for working with I/O

let io_prim @ { IO, File } = import! std.io.prim
let { Read } = import! std.io.read
let { Write } = import! std.io.write
let { Disposable } = import! std.disposable
let { functor, applicative, monad } = import! std.io.base

/// Opens the file at `path` in read-only mode. Fails if the file does not
/// exist.
let open_file path : String -> IO File =
    let { OpenOptions } = io_prim
    io_prim.open_file_with path [Read]

/// Opens a file in write-only mode. If the file already exists, it will be
/// truncated. If the file does not exist, it will be created.
let create_file path : String -> IO File =
    let { OpenOptions } = io_prim
    io_prim.open_file_with path [Create, Write, Truncate]

let read : Read File = {
    read = io_prim.read_file,
    read_to_end = io_prim.read_file_to_end,
}

let write : Write File = {
    write_slice = io_prim.write_slice_file,
    flush = io_prim.flush_file,
}

let disposable : Disposable File = {
    dispose = io_prim.close_file,
    is_disposed = io_prim.is_file_closed,
}

{
    open_file,
    create_file,

    functor,
    applicative,
    monad,
    read,
    write,
    disposable,
    ..
    io_prim
}