Sample of file system TypeProvider

FileSystemTypeProvider.fs

namespace FilesTypeProvider
open System.Reflection
open Microsoft.FSharp.Core.CompilerServices
open Samples.FSharpPreviewRelease2011.ProvidedTypes
open System.Text.RegularExpressions



[<TypeProvider>]
type public CheckedFilesProvider() as this =
    inherit TypeProviderForNamespaces()
    let baseTy = typeof<obj>
    let rec addMembers (path:string) (ownerTy:ProvidedTypeDefinition) = 
        ownerTy.AddXmlDoc "A strongly typed interface to the directory '%s'"
        let dir = new System.IO.DirectoryInfo(path)
        let pathField = ProvidedLiteralField("Path", typeof<string>, dir.FullName);
        pathField.AddXmlDoc "Full path to fullName"
        ownerTy.AddMember pathField
        for sub in dir.EnumerateDirectories() do
                    let subTy = ProvidedTypeDefinition(
                                    typeName = sub.Name.Replace(' ','_'), 
                                    baseType = Some baseTy, 
                                    HideObjectMethods = true)
                    let pathField = ProvidedLiteralField("Path", typeof<string>, sub.FullName)
                    pathField.AddXmlDoc "Full path to fullName"
                    subTy.AddMember pathField
                    addMembersSafe sub.FullName subTy
                    ownerTy.AddMember subTy
        for file in dir.EnumerateFiles() do
                    let subTy = ProvidedTypeDefinition(
                                    typeName = file.Name.Replace(' ','_'), 
                                    baseType = Some baseTy, 
                                    HideObjectMethods = true)
                    let pathField = ProvidedLiteralField("Path", typeof<string>, file.FullName)
                    pathField.AddXmlDoc "Full path to fullName"
                    subTy.AddMember pathField
                    ownerTy.AddMember subTy
    and addMembersSafe (path:string) (ownerTy:ProvidedTypeDefinition) = 
        try
            addMembers path ownerTy
        with | exn ->
                ()

    let thisAssembly = Assembly.GetExecutingAssembly()
    let rootNamespace = "FilesTypeProvider"
    
    let staticParams = [ProvidedStaticParameter("path", typeof<string>)]

    let fileTy = ProvidedTypeDefinition(thisAssembly, rootNamespace, "FileTyped", Some baseTy)

    do fileTy.DefineStaticParameters(
        parameters=staticParams, 
        instantiationFunction=(fun typeName parameterValues ->

          match parameterValues with 
          | [| :? string as path |] -> 
            let ty = ProvidedTypeDefinition(
                        assembly = thisAssembly, 
                        namespaceName = rootNamespace, 
                        typeName = typeName, 
                        baseType = Some baseTy, 
                        HideObjectMethods = true)
            
            
            addMembersSafe path ty
                    
            ty
          | _ -> failwith "unexpected parameter values")) 
    do this.AddNamespace(rootNamespace, [fileTy])
[<TypeProviderAssembly>]
do ()

To use:

r @"C:\Users\hodza\Documents\Visual Studio 11\Projects\FileSystemTypeProvider\FileSystemTypeProvider\bin\Debug\FileSystemTypeProvider.dll"

open FilesTypeProvider

type T = FileTyped< @"C:\Users\hodza\Documents">

printf "Dir path = %s" T.Visual_Studio_2010.Code_Snippets.Nemerle.My_Code_Snippets.Path
.