Lookup functions before refactoring

example1_4.go

// FindPlayerByID returns the player with the given ID, if exists.
// Otherwise, an empty Player is returned.
func FindPlayerByID(ID uint32) Player {
    if p, ok := playerIDMap[ID]; ok {
        return p
    }
    return Player{}
}

// FindPlayerByHandle returns the player with the given Handle,
// if exists. Otherwise, an empty Player is returned.
func FindPlayerByHandle(handle string) Player {
    if p, ok := playerHandleMap[handle]; ok {
        return p
    }
    return Player{}
}

// FindPlayerByCountry returns all players within the given country,
// if exists. Otherwise, an empty slice is returned.
func FindPlayerByCountry(code string) []Player {
    if ps, ok := playerCountryMap[code]; ok {
        return ps
    }
    return []Player{}
}