Modeling the Internet from the scratch: Link-layer, LAN, Switch - Code snippet: Network Topology

host.go

package link

type Link struct {
    cost uint
    ep1  EndPoint
    ep2  EndPoint
}

func (l *Link) AttachEndpoint(ep EndPoint) error {
    ...
}

// Opposite returns other endpoint of given id. If other endpoint does not exist,
// then return error
func (l *Link) Opposite(id Id) (EndPoint, error) {
    ...
}

// EndPoint represents point of link. Link is the channel to pass data to end-point
// either side to the opposite
type EndPoint interface {
    Id() Id
    GetLink() *Link
    AttachLink(link *Link) error
}