Comment by pjmlp

And enums,

   type Colours (Red, Blue, Green)

   //....
   c := Colours.Blue
   a := pred(c)
   b := succ(c)
   
   for x := range Colours { 
      //....
   }

1976's Pascal style is unthinkable to ever land in Go, but we have iota and const, lets not complain.