31 lines
572 B
Go
31 lines
572 B
Go
package observation
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// Compose copies and synchronously invokes non-nil observers in order.
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func Compose[T any, F ~func(T)](observers ...F) F {
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count := 0
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var single F
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for _, observer := range observers {
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if observer != nil {
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count++
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single = observer
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}
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}
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if count == 0 {
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return nil
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}
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if count == 1 {
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return single
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}
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selected := make([]F, 0, count)
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for _, observer := range observers {
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if observer != nil {
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selected = append(selected, observer)
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}
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}
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return func(event T) {
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for _, observer := range selected {
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observer(event)
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}
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}
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}
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