F＃-Array.Parallel模块不可访问

Question

I can access the Array.Parallel module in F# Interactive but not when compiling. What might be wrong ? (VS 2010)

namespace X  // not sent to interactive
open Microsoft.FSharp.Collections
module M = 
  let square  (a _[]) = Array.map          (fun a ->  a*a ) // OK        
  let squareP (a:_[]) = Array.Parallel.map (fun a ->  a*a ) // Error: "Parallel" not defined

This code compiles fine in FSI but when part of a project fails:

------ Erstellen gestartet: Projekt: DELETE TEST, Konfiguration: Debug Any CPU ------ C:\\Program Files (x86)\\Microsoft F#\\v4.0\\fsc.exe -o:obj\\Debug\\DELETE_TEST.dll -g --debug:full --noframework --define:DEBUG --define:TRACE --doc:bin\\Debug\\DELETE_TEST.XML --optimize- --tailcalls- -r:"C:\\Program Files (x86)\\Reference Assemblies\\Microsoft\\FSharp\\2.0\\Runtime\\v2.0\\FSharp.Core.dll" -r:C:\\Windows\\Microsoft.NET\\Framework\\v2.0.50727\\mscorlib.dll -r:"C:\\Program Files (x86)\\Reference Assemblies\\Microsoft\\Framework\\v3.5\\System.Core.dll" -r:C:\\Windows\\Microsoft.NET\\Framework\\v2.0.50727\\System.dll --target:library --warn:3 --warnaserror:76 --vserrors --LCID:1031 --utf8output --fullpaths --flaterrors Module1.fs C:\\work\\Goswin\\30_F#\\16-135_LAD\\DELETE TEST\\Module1.fs(7,37): Fehler FS0039: Der Wert, Konstruktor, Namespace oder Typ "Parallel" ist nicht definiert.

Answer 1

You are targeting .NET 2.0: -r:"C:\\Program Files (x86)\\Reference Assemblies\\Microsoft\\FSharp\\2.0\\Runtime\\v2.0\\FSharp.Core.dll"

The Parallel module is implemented via System.Threading.Tasks , which were not introduced until .NET 4.0. Thus the Parallel module doesn't exist on Array in the .NET 2.0 version of FSharp.Core.dll. If you re-target to 4.0 it will work.

It works in FSI because FSI runs in a .NET 4 environment.