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Create an Observable from an F# Async.
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module AsyncEx | |
open System | |
type Async<'a> with | |
member this.ToObservable() = | |
{ new IObservable<_> with | |
member x.Subscribe(o) = | |
if o = null then nullArg "observer" | |
let cts = new System.Threading.CancellationTokenSource() | |
let invoked = ref 0 | |
let cancelOrDispose cancel = | |
if System.Threading.Interlocked.CompareExchange(invoked, 1, 0) = 0 then | |
if cancel then cts.Cancel() else cts.Dispose() | |
let wrapper = async { | |
try | |
try | |
let! r = this | |
o.OnNext(r) | |
o.OnCompleted() | |
with e -> o.OnError(e) | |
finally cancelOrDispose false } | |
Async.StartImmediate(wrapper, cts.Token) | |
{ new IDisposable with member x.Dispose() = cancelOrDispose true } } |
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