You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: vim.go
    path of file: ./repos/podman/vendor/github.com/chzyer/readline
    
    the code of the file until where you have to start completion: package readline

const (
	VIM_NORMAL = iota
	VIM_INSERT
	VIM_VISUAL
)

type opVim struct {
	cfg     *Config
	op  
    
func (o *opVim) handleVimNormalEnterInsert(r rune, readNext func() rune) (t rune, handled bool) {
	rb := o.op.buf
	handled = true
	switch r {
	case 'i':
	case 'I':
		rb.MoveToLineStart()
	case 'a':
		rb.MoveForward()
	case 'A':
		rb.MoveToLineEnd()
	case 's':
		rb.Delete()
	case 'S':
		rb.Erase()
	case 'c':
		next := readNext()
		switch next {
		case 'c':
			rb.Erase()
		case 'w':
			rb.DeleteWord()
		case 'h':
			rb.Backspace()
		case 'l':
			rb.Delete()
		}
	default:
		return r, false
	}

	o.EnterVimInsertMode()
	return
}