Async file I/O operations with Exception-based error handling.

Wraps a file descriptor with typed async I/O operations. Uses the Exception effect for error handling.

Example

{ File, read_string, write_file, OpenMode } :: import "std/fs/file";

main :: (fn(io : Io, exn : Exception) -> unit)({
  // Write a file
  io.await(write_file(Path.new(`test.txt`), `hello world`, io), { io, exn });

  // Read it back
  content := io.await(read_string(Path.new(`test.txt`), io), { io, exn });
  println(content);

  // Open with OpenMode
  f := io.await(File.open(Path.new(`test.txt`), .Read, io), { io, exn });
});