AsyncBuilder.While Method (F#)

Implements the while keyword in asynchronous computation expressions.

Namespace/Module Path: Microsoft.FSharp.Control

Assembly: FSharp.Core (in FSharp.Core.dll)

// Signature:
member this.While : (unit -> bool) * Async<unit> -> Async<unit>

// Usage:
asyncBuilder.While (guard, computation)

Parameters

• guard
  Type: unit -> bool

  The function to determine when to stop executing computation.

• computation
  Type: Async<unit>

  The function to be executed. Equivalent to the body of a while expression.

Return Value

An asynchronous computation that behaves similarly to a while loop when run.

Remarks

Creates an asynchronous computation that runs computation repeatedly until guard evaluates to false.

A cancellation check is performed whenever the computation is executed. The existence of this method permits the use of while in the async { ... } computation expression syntax.

Platforms

Windows 7, Windows Vista SP2, Windows XP SP3, Windows XP x64 SP2, Windows Server 2008 R2, Windows Server 2008 SP2, Windows Server 2003 SP2

Version Information

F# Runtime

Supported in: 2.0, 4.0

Silverlight

Supported in: 3

See Also

Reference

Control.AsyncBuilder Class (F#)

Microsoft.FSharp.Control Namespace (F#)