cli

type App struct {
	Commands []Command
	Flags    []Flag

	// UserOut logs messages to end-users
	UserOut io.Writer
	// UserErr logs errors to end-users
	UserErr io.Writer
	// InternalOut logs messages to ops
	InternalOut io.Writer

	Before func(c *Context) error

	Exit <-chan struct{}
}

type BoolFlag struct {
	Name  string
	Usage string
}

type Command struct {
	Name  string
	Flags []Flag

	Run func(context *Context) (exitStatus int, err error)
}

type Context struct {
	App         *App
	CommandName string
	Command     *Command
	Flags       *FlagSet
	Args        []string
	Exit        <-chan struct{}
}

type Flag interface {
	Apply(*flag.FlagSet)
}

type FlagSet struct {
	*flag.FlagSet
}

type IntFlag struct {
	Name  string
	Value int
	Usage string
}

type StringFlag struct {
	Name  string
	Value string
	Usage string
}

type StringSliceFlag struct {
	Name  string
	Value *stringSlice
	Usage string
}