context

type Context struct {
	Context context.Context
	Stdin   io.Reader
	Stdout  io.Writer
	Stderr  io.Writer
	Value   cue.Value
	Error   error

	// Global lock around CUE evaluator
	CUELock *sync.Mutex

	// map of cue.Values
	ValStore *sync.Map

	// map of chan?
	Mailbox *sync.Map
}

type Runner interface {
	// Runner runs given the current value and returns a new value which is to
	// be unified with the original result.
	Run(ctx *Context) (results interface{}, err error)
}

type RunnerFunc func(v cue.Value) (Runner, error)