diskio

type File[A ~int64] interface {
	Name() string
	Size() A
	io.Closer
	ReaderAt[A]
	WriteAt(p []byte, off A) (n int, err error)
}

type OSFile[A ~int64] struct {
	*os.File
}

type ReaderAt[A ~int64] interface {
	ReadAt(p []byte, off A) (n int, err error)
}

type Ref[A ~int64, T any] struct {
	File File[A]
	Addr A
	Data T
}

type Sequence[K ~int64 | ~int, V any] interface {
	SeqLen() K
	// Get the value at 'pos' in the sequence.  Positions start at
	// 0 and increment naturally.  It is invalid to call
	// SeqGet(pos) with a pos that is >= SeqLen().
	SeqGet(pos K) V
}

type SliceSequence[K ~int64 | ~int, V any] []V

type StringSequence[K ~int64 | ~int] string