如何在编译的F#程序中执行字符串中的F#代码？

如何从已编译的F#程序中的字符串执行F#代码？

这是一个使用FSharp CodeDom将字符串编译成程序集并将其动态加载到脚本会话中的小脚本.

它使用类型扩展只是为了允许参数有用的默认值(希望绑定函数在不久的将来支持可选,命名和参数参数.)

#r "FSharp.Compiler.dll"
#r "FSharp.Compiler.CodeDom.dll"

open System
open System.IO
open System.CodeDom.Compiler
open Microsoft.FSharp.Compiler.CodeDom

let CompileFSharpString(str, assemblies, output) =
        use pro = new FSharpCodeProvider()
        let opt = CompilerParameters(assemblies, output)
        let res = pro.CompileAssemblyFromSource( opt, [|str|] )
        if res.Errors.Count = 0 then 
             Some(FileInfo(res.PathToAssembly)) 
        else None

let (++) v1 v2   = Path.Combine(v1, v2)    
let defaultAsms  = [|"System.dll"; "FSharp.Core.dll"; "FSharp.Powerpack.dll"|] 
let randomFile() = __SOURCE_DIRECTORY__ ++ Path.GetRandomFileName() + ".dll"   

type System.CodeDom.Compiler.CodeCompiler with 
    static member CompileFSharpString (str, ?assemblies, ?output) =
        let assemblies  = defaultArg assemblies defaultAsms
        let output      = defaultArg output (randomFile())
        CompileFSharpString(str, assemblies, output)     

// Our set of library functions.
let library = "

module Temp.Main
let f(x,y) = sin x + cos y
"
// Create the assembly
let fileinfo = CodeCompiler.CompileFSharpString(library)

// Import metadata into the FSharp typechecker
#r "0lb3lphm.del.dll"

let a = Temp.Main.f(0.5 * Math.PI, 0.0)     // val a : float = 2.0

// Purely reflective invocation of the function.
let asm = Reflection.Assembly.LoadFrom(fileinfo.Value.FullName)
let mth  = asm.GetType("Temp.Main").GetMethod("f")

// Wrap weakly typed function with strong typing.
let f(x,y) = mth.Invoke(null, [|box (x:float); box (y:float)|]) :?> float

let b = f (0.5 * Math.PI, 0.0)              // val b : float = 2.0

要在已编译的程序中使用它,您需要纯粹的反射调用.

当然,与我们社区中许多人迫切要求的完整脚本API相比,这是一个玩具.

祝你好运,

丹尼

您在寻找Eval功能吗？

您可能想尝试查看此博客文章:

http://fsharpnews.blogspot.com/2007/02/symbolic-manipulation.html

如果您将表达式读入这些符号数据结构,它们很容易评估.

或者,也许您正在寻找脚本支持:

http://blogs.msdn.com/chrsmith/archive/2008/09/12/scripting-in-f.aspx

如果您真的想要动态编译,可以使用F#CodeDom提供程序.