future

The future package aims to provide a simple interface for consuming return values and/or errors from a Future.

It provides the SettableFuture struct and a Future interface for consumers. This distinction allows explicit decoupling of value providers and consumers.

The following example demonstrates the interfaces:

settableFuture := future.New()
settableFuture.Set(1, nil)

var f future.Future = settableFuture
<-f.Done()
fmt.Println(f.Value().(int)) // prints 1
fmt.Println(f.Err())         // prints <nil>
fmt.Println(f.Result())      // prints 1 <nil>

fmt.Println(f.Wait(context.Background())) // prints 1 <nil>

f.Then(func(i int) {
    fmt.Println(i) // prints 1
}).Catch(func (e error) {
    fmt.Println(e) // doesn't run
})

See godoc for full package documentation.