Just for FUN--GO implement the Observer pattern

This is a creation in Article, where the information may have evolved or changed.

Code

Package Mainimport ("FMT") type Subject interface {registerobserver (o Observer) removeobserver (o Observer) No Tifyallobservers ()}type Observer Interface {//temperature, humidity, barometric Update (temp float32, humidity float32, pressure float32)}ty PE weatherdata struct {temperature float32 humidity float32 pressure float32 observers map[observer]b Ool}func Newweathdata () *weatherdata {return &weatherdata{observers:make (Map[observer]bool),}}func (w D *weatherdata) registerobserver (o Observer) {wd. Observers[o] = True}func (wd *weatherdata) removeobserver (o Observer) {if _, OK: = WD. Observers[o]; OK {Delete (wd). Observers, O)}}func (wd *weatherdata) Notifyallobservers () {for O, _: = Range WD. Observers {O.update (WD. Temperature, WD. Humidity, WD. pressure)}}func (wd *weatherdata) setmeasurements (temp float32, humidity float32, pressure float32) {wd. Temperature = temp WD. Humidity = Humidity WD.  pressure = pressure  Wd. Notifyallobservers ()}type currentconditionsdisplay struct {temperature float32 humidity float32 Weathdata S Ubject}func Newcurrentconditionsdisplay (weathdata Subject) *currentconditionsdisplay {CCD: = & currentconditionsdisplay{Weathdata:weathdata,} weathdata.registerobserver (CCD) return Ccd}func (CCD *Cu Rrentconditionsdisplay) Update (temp float32, humidity float32, pressure float32) {CCD. Temperature = temp CCD. Humidity = humidity//pressure no use to CCD. Display ()}func (CCD *currentconditionsdisplay) display () {FMT. PRINTLN ("Current conditions:" + FMT. Sprintf ("%v", CCD. Temperature) + "F degrees and" + FMT. Sprintf ("%v", CCD. Humidity) + "% humidity")}func main () {weathdata: = Newweathdata () _ = Newcurrentconditionsdisplay (Weathdata) we Athdata.setmeasurements (30.4, weathdata.setmeasurements, 29.2) weathdata.setmeasurements (78, 90, 29.2 )}

Test

Output

Current conditions: 80F degrees and 65% humidityCurrent conditions: 82F degrees and 70% humidityCurrent conditions: 78F degrees and 90% humidity