f#

问题 I' m using JetBrains Rider on MacOS and experimenting with code from Scott Wlaschin Domain Modelling Made Functional Here are my module definition and it dependencies: module internal DomainModeling.Domain.PlaceOrderWorkflow.Internal open DomainModeling.Domain.Api open DomainModeling.Domain.Primitives open DomainModeling.Domain.Utils I want to generate signature file from this module. But I'm confused of using dotnet builder or fsharp compiler. If I use dotnet command I can't pass flag --sig

问题 I' m using JetBrains Rider on MacOS and experimenting with code from Scott Wlaschin Domain Modelling Made Functional Here are my module definition and it dependencies: module internal DomainModeling.Domain.PlaceOrderWorkflow.Internal open DomainModeling.Domain.Api open DomainModeling.Domain.Primitives open DomainModeling.Domain.Utils I want to generate signature file from this module. But I'm confused of using dotnet builder or fsharp compiler. If I use dotnet command I can't pass flag --sig

问题 I need to call a function that takes System.Array [] as one parameter in F#. (The function is in a library). I need to pass an argument of type float [] [] [] but the compiler refuses to compile. To replicate the problem, I wrote the following code let x : float [] [] = Array.init 2 (fun x -> Array.zeroCreate 3) x :> System.Array;; // This is OK val x : float [] [] = [|[|0.0; 0.0; 0.0|]; [|0.0; 0.0; 0.0|]|] > x :> System.Array [];; //Error x :> System.Array [];; ^^^^^^^^^^^^^^^^^^^^ stdin(14

问题 I need to call a function that takes System.Array [] as one parameter in F#. (The function is in a library). I need to pass an argument of type float [] [] [] but the compiler refuses to compile. To replicate the problem, I wrote the following code let x : float [] [] = Array.init 2 (fun x -> Array.zeroCreate 3) x :> System.Array;; // This is OK val x : float [] [] = [|[|0.0; 0.0; 0.0|]; [|0.0; 0.0; 0.0|]|] > x :> System.Array [];; //Error x :> System.Array [];; ^^^^^^^^^^^^^^^^^^^^ stdin(14

问题 Just curious why I can't do this: let myFn (data : obj) = match data with | :? (string * string) as (s1, s2) -> sprintf "(%s, %s)" s1 s2 |> Some | :? (string * string * int) as (s1, s2, i) -> sprintf "(%s, %s, %d)" s1 s2 i |> Some | _ -> None How come? 回答1: See F# spec, section 7.3 "As patterns" An as pattern is of the form pat as ident Which means you need to use an identifier after as : let myFn (data : obj) = match data with | :? (string * string) as s1s2 -> let (s1, s2) = s1s2 in sprintf

问题 I can't compile the following code, which has been translated from C#. The compiler produced this error: error FS0010: Incomplete structured construct at or before this point in implementation file. Expected incomplete structured construct at or before this point or other token. // Assemblies open System open System.Linq open System.Data open System.Windows open DocumentFormat.OpenXml // Also install DocumentFormat.OpenXml from nuget open DocumentFormat.OpenXml.Packaging open DocumentFormat

问题 I can't compile the following code, which has been translated from C#. The compiler produced this error: error FS0010: Incomplete structured construct at or before this point in implementation file. Expected incomplete structured construct at or before this point or other token. // Assemblies open System open System.Linq open System.Data open System.Windows open DocumentFormat.OpenXml // Also install DocumentFormat.OpenXml from nuget open DocumentFormat.OpenXml.Packaging open DocumentFormat

问题 So I'm getting the "This construct causes code to be less generic than indicated by the type annotations. The type variable 'a has been constrained to be type 'CountType'." warning, and the constraint is causing a problem in other bits of the code. I've tried making the type explicitly generic, but it's not working. I've put this code on tryfsharp to make it easier to play with. Apologies for the mound of code, I tried cutting it down and simplifying some types. module Stuff type CountType =

问题 So I'm getting the "This construct causes code to be less generic than indicated by the type annotations. The type variable 'a has been constrained to be type 'CountType'." warning, and the constraint is causing a problem in other bits of the code. I've tried making the type explicitly generic, but it's not working. I've put this code on tryfsharp to make it easier to play with. Apologies for the mound of code, I tried cutting it down and simplifying some types. module Stuff type CountType =

问题 So I'm getting the "This construct causes code to be less generic than indicated by the type annotations. The type variable 'a has been constrained to be type 'CountType'." warning, and the constraint is causing a problem in other bits of the code. I've tried making the type explicitly generic, but it's not working. I've put this code on tryfsharp to make it easier to play with. Apologies for the mound of code, I tried cutting it down and simplifying some types. module Stuff type CountType =