55 lines
915 B
Go
55 lines
915 B
Go
package emitter
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import "git.maximhutz.com/max/lambda/pkg/set"
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type Observer struct {
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fn func()
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message string
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emitter *Emitter
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}
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type Emitter struct {
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listeners map[string]*set.Set[*Observer]
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}
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func Ignore[T any](fn func()) func(T) {
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return func(T) { fn() }
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}
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func (e *Emitter) On(message string, fn func()) *Observer {
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observer := &Observer{
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fn: fn,
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message: message,
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emitter: e,
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}
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if e.listeners == nil {
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e.listeners = map[string]*set.Set[*Observer]{}
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}
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if e.listeners[message] == nil {
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e.listeners[message] = set.New[*Observer]()
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}
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e.listeners[message].Add(observer)
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return observer
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}
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func (o *Observer) Off() {
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if o.emitter.listeners[o.message] == nil {
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return
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}
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o.emitter.listeners[o.message].Remove(o)
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}
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func (e *Emitter) Emit(message string) {
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if e.listeners[message] == nil {
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return
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}
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for listener := range *e.listeners[message] {
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listener.fn()
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}
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}
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