f#-interactive

问题 Here is the scenario: Open Visual Studio. This was done in VS2010 Pro. Open F# Interactive within Visual Studio Open project with fsx file Note: Project and fsx file are in E:\<directories>\fsharp-tapl\arith Send commands to F# Interactive from fsx file > System.Environment.CurrentDirectory;; val it : string = "C:\Users\Eric\AppData\Local\Temp" I was not expecting a Temp directory but it makes sense. > #r @"arith.exe" Examples.fsx(7,1): error FS0082: Could not resolve this reference. Could

问题 According to the MSDN documentaion: When set to false, disables the display of declaration values in the output of the interactive session. However, the following sample interactive session seems to contradict that summary. > let x = 42;; val x : int = 42 > fsi.ShowDeclarationValues <- false;; val it : unit = () > let y = 42;; val y : int I was not expecting the last line above. Have I misunderstood something? Can anyone confirm if this is a bug? Thanks. 回答1: Daniel is correct - this disables

问题 I want to replace GetPixel and SetPixel using LockBits method, so I came across this F# lazy pixels reading open System.Drawing open System.Drawing.Imaging let pixels (image:Bitmap) = let Width = image.Width let Height = image.Height let rect = new Rectangle(0,0,Width,Height) // Lock the image for access let data = image.LockBits(rect, ImageLockMode.ReadOnly, image.PixelFormat) // Copy the data let ptr = data.Scan0 let stride = data.Stride let bytes = stride * data.Height let values : byte[]

问题 Somewhat of a F# beginner. I'm trying to test out some of my XmlTypeProvider code in the interactive window by first entering it in a script (fsx) file. The script file won't recognize the following open FSharp.Data // gives "The namespace or module 'FSharp' is not defined" Everything has been added to reference, and .fs files seem to not have any problems finding the XmlTypeProvider reference but for some reason, a script in the same project does not. I even got the code to work in a .fs

问题 If one uses the F# Interactive Shell (FSI), the inferred expression type (signature) is printed to the console along with its value: val it : int * string * float = (42, "Hello F#", 42.0) How can I mimick the same behaviour in my own code, e.g. to get the inferred types as string for a F# expression? I don't need to dynamically evaluate any F# expressions, the expressions are known in compile time and are part of my (static) F# code. I need this feature to be able to mimick the FSI output in

问题 I'm sure this must be something really easy, but I can't seem to make it work. Let's say I have an .fsx script file and want to cause it to be executed programmatically. I'm guessing someone must have blogged about this at some point, but I can't seem to find an example that performs my simple scenario. Basically, I want to programmatically duplicate what happens when you right click on an .fsx file and choose "Run with F# Interactive..." 回答1: As asked in a comment, you can set

问题 What kind of strategy do I have for the following problem. I want to use a simple class inside a dll, which has link to various dlls, of various versions etc. As a fsx file, my script show no error. but upon running it in fsharp interactive, it tells me error FS0074: The type referenced through 'theTypeIWantToUse' is defined in an assembly that is not referenced. You must add a reference to assembly 'Assembly'. Of course the assembly is referenced, so I imagine I need to add references to

问题 I have a need to capture the input and output of F# functions when using F# Interactive. I am able to get NLog to work just fine when the program is run under Visual Studio using F5 or Ctrl-F5. Also the same methods that contain statements to output to the log work just fine and are called when invoked via F# Interactive; just nothing in the log file. I also tried the following with F# Interactive to setup references to NLog and still nothing in the log when run from F# Interactive. #I @"..

问题 I'd like to write some code that runs a sequence of F# scripts (.fsx). The thing is that I could have literally hundreds of scripts and if I do that: let shellExecute program args = let startInfo = new ProcessStartInfo() do startInfo.FileName <- program do startInfo.Arguments <- args do startInfo.UseShellExecute <- true do startInfo.WindowStyle <- ProcessWindowStyle.Hidden //do printfn "%s" startInfo.Arguments let proc = Process.Start(startInfo) () scripts |> Seq.iter (shellExecute "fsi") it

问题 I've read through a good chunk of Expert F# and am working on building an actual application. While debugging, I've grown accustomed to passing fsi commands like this to make things legible in the repl window: fsi.AddPrinter(fun (x : myType) -> myType.ToString()) I would like to extend this to work with the printf formatter, so I could type e.g. printf "%A" instanceOfMyType and control the output for a custom type. The book implies that this can be done (p 93, "Generic structural formatting