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Call/CC for Async
An implementation of call-with-current-continuation for Async.
Async.callcc
1: let callcc (f: ('a -> Async<'b>) -> Async<'a>) : Async<'a> = 2: Async.FromContinuations(fun (cont, econt, ccont) -> 3: Async.StartWithContinuations(f (fun a -> Async.FromContinuations(fun (_, _, _) -> cont a)), cont, econt, ccont))
Test sample
1: (* Test callcc *) 2: let sum l = 3: let rec sum l = async { 4: let! result = callcc (fun exit1 -> async { 5: match l with 6: | [] -> return 0 7: | h::t when h = 2 -> return! exit1 42 8: | h::t -> let! r = sum t 9: return h + r }) 10: return result } 11: Async.RunSynchronously(sum l) 12: 13: [<Test>] 14: let ``When summing a list without a 2 via callcc it should return 8``() = 15: sum [1;1;3;3] |> should equal 8 16: 17: [<Test>] 18: let ``When summing a list containing 2 via callcc it should return 43``() = 19: sum [1;2;3] |> should equal 43
val callcc : (('a -> Async<'b>) -> Async<'a>) -> Async<'a>
Full name: Snippet.callcc
Full name: Snippet.callcc
val f : (('a -> Async<'b>) -> Async<'a>)
Multiple items
type Async<'T>
Full name: Microsoft.FSharp.Control.Async<_>
--------------------
type Async
with
static member AsBeginEnd : computation:('Arg -> Async<'T>) -> ('Arg * System.AsyncCallback * obj -> System.IAsyncResult) * (System.IAsyncResult -> 'T) * (System.IAsyncResult -> unit)
static member AwaitEvent : event:IEvent<'Del,'T> * ?cancelAction:(unit -> unit) -> Async<'T> (requires delegate and 'Del :> System.Delegate)
static member AwaitIAsyncResult : iar:System.IAsyncResult * ?millisecondsTimeout:int -> Async<bool>
static member AwaitTask : task:System.Threading.Tasks.Task<'T> -> Async<'T>
static member AwaitWaitHandle : waitHandle:System.Threading.WaitHandle * ?millisecondsTimeout:int -> Async<bool>
static member CancelDefaultToken : unit -> unit
static member Catch : computation:Async<'T> -> Async<Choice<'T,exn>>
static member FromBeginEnd : beginAction:(System.AsyncCallback * obj -> System.IAsyncResult) * endAction:(System.IAsyncResult -> 'T) * ?cancelAction:(unit -> unit) -> Async<'T>
static member FromBeginEnd : arg:'Arg1 * beginAction:('Arg1 * System.AsyncCallback * obj -> System.IAsyncResult) * endAction:(System.IAsyncResult -> 'T) * ?cancelAction:(unit -> unit) -> Async<'T>
static member FromBeginEnd : arg1:'Arg1 * arg2:'Arg2 * beginAction:('Arg1 * 'Arg2 * System.AsyncCallback * obj -> System.IAsyncResult) * endAction:(System.IAsyncResult -> 'T) * ?cancelAction:(unit -> unit) -> Async<'T>
static member FromBeginEnd : arg1:'Arg1 * arg2:'Arg2 * arg3:'Arg3 * beginAction:('Arg1 * 'Arg2 * 'Arg3 * System.AsyncCallback * obj -> System.IAsyncResult) * endAction:(System.IAsyncResult -> 'T) * ?cancelAction:(unit -> unit) -> Async<'T>
static member FromContinuations : callback:(('T -> unit) * (exn -> unit) * (System.OperationCanceledException -> unit) -> unit) -> Async<'T>
static member Ignore : computation:Async<'T> -> Async<unit>
static member OnCancel : interruption:(unit -> unit) -> Async<System.IDisposable>
static member Parallel : computations:seq<Async<'T>> -> Async<'T []>
static member RunSynchronously : computation:Async<'T> * ?timeout:int * ?cancellationToken:System.Threading.CancellationToken -> 'T
static member Sleep : millisecondsDueTime:int -> Async<unit>
static member Start : computation:Async<unit> * ?cancellationToken:System.Threading.CancellationToken -> unit
static member StartAsTask : computation:Async<'T> * ?taskCreationOptions:System.Threading.Tasks.TaskCreationOptions * ?cancellationToken:System.Threading.CancellationToken -> System.Threading.Tasks.Task<'T>
static member StartChild : computation:Async<'T> * ?millisecondsTimeout:int -> Async<Async<'T>>
static member StartChildAsTask : computation:Async<'T> * ?taskCreationOptions:System.Threading.Tasks.TaskCreationOptions -> Async<System.Threading.Tasks.Task<'T>>
static member StartImmediate : computation:Async<unit> * ?cancellationToken:System.Threading.CancellationToken -> unit
static member StartWithContinuations : computation:Async<'T> * continuation:('T -> unit) * exceptionContinuation:(exn -> unit) * cancellationContinuation:(System.OperationCanceledException -> unit) * ?cancellationToken:System.Threading.CancellationToken -> unit
static member SwitchToContext : syncContext:System.Threading.SynchronizationContext -> Async<unit>
static member SwitchToNewThread : unit -> Async<unit>
static member SwitchToThreadPool : unit -> Async<unit>
static member TryCancelled : computation:Async<'T> * compensation:(System.OperationCanceledException -> unit) -> Async<'T>
static member CancellationToken : Async<System.Threading.CancellationToken>
static member DefaultCancellationToken : System.Threading.CancellationToken
end
Full name: Microsoft.FSharp.Control.Async
type Async<'T>
Full name: Microsoft.FSharp.Control.Async<_>
--------------------
type Async
with
static member AsBeginEnd : computation:('Arg -> Async<'T>) -> ('Arg * System.AsyncCallback * obj -> System.IAsyncResult) * (System.IAsyncResult -> 'T) * (System.IAsyncResult -> unit)
static member AwaitEvent : event:IEvent<'Del,'T> * ?cancelAction:(unit -> unit) -> Async<'T> (requires delegate and 'Del :> System.Delegate)
static member AwaitIAsyncResult : iar:System.IAsyncResult * ?millisecondsTimeout:int -> Async<bool>
static member AwaitTask : task:System.Threading.Tasks.Task<'T> -> Async<'T>
static member AwaitWaitHandle : waitHandle:System.Threading.WaitHandle * ?millisecondsTimeout:int -> Async<bool>
static member CancelDefaultToken : unit -> unit
static member Catch : computation:Async<'T> -> Async<Choice<'T,exn>>
static member FromBeginEnd : beginAction:(System.AsyncCallback * obj -> System.IAsyncResult) * endAction:(System.IAsyncResult -> 'T) * ?cancelAction:(unit -> unit) -> Async<'T>
static member FromBeginEnd : arg:'Arg1 * beginAction:('Arg1 * System.AsyncCallback * obj -> System.IAsyncResult) * endAction:(System.IAsyncResult -> 'T) * ?cancelAction:(unit -> unit) -> Async<'T>
static member FromBeginEnd : arg1:'Arg1 * arg2:'Arg2 * beginAction:('Arg1 * 'Arg2 * System.AsyncCallback * obj -> System.IAsyncResult) * endAction:(System.IAsyncResult -> 'T) * ?cancelAction:(unit -> unit) -> Async<'T>
static member FromBeginEnd : arg1:'Arg1 * arg2:'Arg2 * arg3:'Arg3 * beginAction:('Arg1 * 'Arg2 * 'Arg3 * System.AsyncCallback * obj -> System.IAsyncResult) * endAction:(System.IAsyncResult -> 'T) * ?cancelAction:(unit -> unit) -> Async<'T>
static member FromContinuations : callback:(('T -> unit) * (exn -> unit) * (System.OperationCanceledException -> unit) -> unit) -> Async<'T>
static member Ignore : computation:Async<'T> -> Async<unit>
static member OnCancel : interruption:(unit -> unit) -> Async<System.IDisposable>
static member Parallel : computations:seq<Async<'T>> -> Async<'T []>
static member RunSynchronously : computation:Async<'T> * ?timeout:int * ?cancellationToken:System.Threading.CancellationToken -> 'T
static member Sleep : millisecondsDueTime:int -> Async<unit>
static member Start : computation:Async<unit> * ?cancellationToken:System.Threading.CancellationToken -> unit
static member StartAsTask : computation:Async<'T> * ?taskCreationOptions:System.Threading.Tasks.TaskCreationOptions * ?cancellationToken:System.Threading.CancellationToken -> System.Threading.Tasks.Task<'T>
static member StartChild : computation:Async<'T> * ?millisecondsTimeout:int -> Async<Async<'T>>
static member StartChildAsTask : computation:Async<'T> * ?taskCreationOptions:System.Threading.Tasks.TaskCreationOptions -> Async<System.Threading.Tasks.Task<'T>>
static member StartImmediate : computation:Async<unit> * ?cancellationToken:System.Threading.CancellationToken -> unit
static member StartWithContinuations : computation:Async<'T> * continuation:('T -> unit) * exceptionContinuation:(exn -> unit) * cancellationContinuation:(System.OperationCanceledException -> unit) * ?cancellationToken:System.Threading.CancellationToken -> unit
static member SwitchToContext : syncContext:System.Threading.SynchronizationContext -> Async<unit>
static member SwitchToNewThread : unit -> Async<unit>
static member SwitchToThreadPool : unit -> Async<unit>
static member TryCancelled : computation:Async<'T> * compensation:(System.OperationCanceledException -> unit) -> Async<'T>
static member CancellationToken : Async<System.Threading.CancellationToken>
static member DefaultCancellationToken : System.Threading.CancellationToken
end
Full name: Microsoft.FSharp.Control.Async
static member Async.FromContinuations : callback:(('T -> unit) * (exn -> unit) * (System.OperationCanceledException -> unit) -> unit) -> Async<'T>
val cont : ('a -> unit)
val econt : (exn -> unit)
val ccont : (System.OperationCanceledException -> unit)
static member Async.StartWithContinuations : computation:Async<'T> * continuation:('T -> unit) * exceptionContinuation:(exn -> unit) * cancellationContinuation:(System.OperationCanceledException -> unit) * ?cancellationToken:System.Threading.CancellationToken -> unit
val a : 'a
val sum : int list -> int
Full name: Snippet.sum
Full name: Snippet.sum
val l : int list
type: int list
implements: System.Collections.IStructuralEquatable
implements: System.IComparable<List<int>>
implements: System.IComparable
implements: System.Collections.IStructuralComparable
implements: System.Collections.Generic.IEnumerable<int>
implements: System.Collections.IEnumerable
type: int list
implements: System.Collections.IStructuralEquatable
implements: System.IComparable<List<int>>
implements: System.IComparable
implements: System.Collections.IStructuralComparable
implements: System.Collections.Generic.IEnumerable<int>
implements: System.Collections.IEnumerable
val sum : (int list -> Async<int>)
val async : AsyncBuilder
Full name: Microsoft.FSharp.Core.ExtraTopLevelOperators.async
Full name: Microsoft.FSharp.Core.ExtraTopLevelOperators.async
val result : int
type: int
implements: System.IComparable
implements: System.IFormattable
implements: System.IConvertible
implements: System.IComparable<int>
implements: System.IEquatable<int>
inherits: System.ValueType
type: int
implements: System.IComparable
implements: System.IFormattable
implements: System.IConvertible
implements: System.IComparable<int>
implements: System.IEquatable<int>
inherits: System.ValueType
val exit1 : (int -> Async<int>)
val h : int
type: int
implements: System.IComparable
implements: System.IFormattable
implements: System.IConvertible
implements: System.IComparable<int>
implements: System.IEquatable<int>
inherits: System.ValueType
type: int
implements: System.IComparable
implements: System.IFormattable
implements: System.IConvertible
implements: System.IComparable<int>
implements: System.IEquatable<int>
inherits: System.ValueType
val t : int list
type: int list
implements: System.Collections.IStructuralEquatable
implements: System.IComparable<List<int>>
implements: System.IComparable
implements: System.Collections.IStructuralComparable
implements: System.Collections.Generic.IEnumerable<int>
implements: System.Collections.IEnumerable
type: int list
implements: System.Collections.IStructuralEquatable
implements: System.IComparable<List<int>>
implements: System.IComparable
implements: System.Collections.IStructuralComparable
implements: System.Collections.Generic.IEnumerable<int>
implements: System.Collections.IEnumerable
val r : int
type: int
implements: System.IComparable
implements: System.IFormattable
implements: System.IConvertible
implements: System.IComparable<int>
implements: System.IEquatable<int>
inherits: System.ValueType
type: int
implements: System.IComparable
implements: System.IFormattable
implements: System.IConvertible
implements: System.IComparable<int>
implements: System.IEquatable<int>
inherits: System.ValueType
static member Async.RunSynchronously : computation:Async<'T> * ?timeout:int * ?cancellationToken:System.Threading.CancellationToken -> 'T
type TestAttribute =
class
inherit System.Attribute
new : unit -> NUnit.Framework.TestAttribute
member Description : string with get, set
end
Full name: NUnit.Framework.TestAttribute
type: TestAttribute
implements: System.Runtime.InteropServices._Attribute
inherits: System.Attribute
class
inherit System.Attribute
new : unit -> NUnit.Framework.TestAttribute
member Description : string with get, set
end
Full name: NUnit.Framework.TestAttribute
type: TestAttribute
implements: System.Runtime.InteropServices._Attribute
inherits: System.Attribute
More information
| Link: | http://fssnip.net/7U |
| Posted: | 1 years ago |
| Author: | Ryan Riley (website) |
| Tags: | async, continuation, callcc |