Compile-time safety for enumerations in Go

Re:Compile-time safety for enumerations in Go by hamdouni on Saturday September 30, 2023 @06:09AM (#37714077)

It's the game of the mouse and the cat :-D We can change the package color like this :

  package color

  type Color interface {
    void()
  }

  type color struct {
    v string
  }

  func (c color) void() {}
  func (c color) String() string {
    return c.v
  }

  var (
    Red   color = color{"red"}
    Green color = color{"green"}
    Blue  color = color{"blue"}
  )

[ Parent | on HN ]

Re:Compile-time safety for enumerations in Go by kiitos on Sunday October 01, 2023 @10:37PM (#37733330)

    func fn(c color.Color) {
     switch c {
     case color.Red, color.Green, color.Blue:
      log.Printf("c=%#+v -- OK", c)
     default:
      log.Printf("c=%#+v -- should not be possible", c)
     }
    }
    
    func main() {
     var c color.Color
     fn(c)
    }

Output:

    c=<nil> -- should not be possible

:shrug:

[ Parent | on HN ]