package game import ( "fmt" ) type Position struct { X int Y int } const POSITION_FMT = "(%d, %d)" func (p Position) String() string { if p == INVALID_POSITION() { return "INVALID_POSITION" } return fmt.Sprintf(POSITION_FMT, p.X, p.Y) } func INVALID_POSITION() Position { return Position{-1, -1} }