Simple F# Type Provider for Mutable Records

RecordProvider.fs

namespace TestProvider.Provided

open System.Reflection
open FSharp.Core.CompilerServices
open ProviderImplementation.ProvidedTypes
open System.Collections.Generic
open Microsoft.FSharp.Quotations

[<TypeProvider>]
type SampleProvider(config) as this =
    inherit TypeProviderForNamespaces(config)

    let ns = "SampleProvider.Provided"

    let asm = Assembly.GetExecutingAssembly()


    let addProperty (name: string) (_: 'T) (baseType: ProvidedTypeDefinition) =

        let getter (args: Quotations.Expr list) = <@@ ((%%args.[0]:obj) :?> Dictionary<string,obj>).[name] :?> 'T @@>
        let setter (args: Quotations.Expr list) = <@@ ((%%args.[0]:obj) :?> Dictionary<string,obj>).[name] <- (%%args.[1]:'T) @@>

        let myInstanceProperty =
            ProvidedProperty(name,
                typeof<'T>,
                isStatic = false,
                getterCode = getter,
                setterCode = setter)


        baseType.AddMember myInstanceProperty
        baseType

    let addMethod (method: ProvidedMethod) (baseType: ProvidedTypeDefinition) =
        baseType.AddMember method
        baseType

    let createType name (parameters: obj[]) =

        let aString = parameters.[0] :?> string

        let myType = ProvidedTypeDefinition(asm, ns, name, Some typeof<obj>, isErased = true)

        let props = [
            "FirstName"
            "LastName"
            "Date"
        ]

        let propExpr = Expr.NewArray(typeof<string>, props |> List.map (Expr.Value))

        let constructor =
            <@@
                let items = %%propExpr:string[]
                let d = Dictionary<string, obj>()
                for item in items do
                    d.Add(item, null)
                d
            @@>

        let ctor = ProvidedConstructor([], invokeCode = fun args -> constructor)
        myType.AddMember(ctor)

        let greetMethod (args: Expr list) =
            <@@
                let state = (%%args.[0]:obj) :?> Dictionary<string,obj>
                let firstName = state.["FirstName"]:?> string
                let lastName = state.["LastName"] :?> string
                let date = state.["Date"] :?> System.DateTime
                sprintf "Hello my name is %s %s, The time is %O" firstName lastName date
            @@>

        let greet = ProvidedMethod("Greet",[],typeof<string>,isStatic = false, invokeCode = greetMethod)

        myType
        |> addProperty props.[0] Unchecked.defaultof<string>
        |> addProperty props.[1] Unchecked.defaultof<string>
        |> addProperty props.[2] Unchecked.defaultof<System.DateTime>
        |> addMethod greet


    let provider =
        ProvidedTypeDefinition(asm,ns, "RecordProvider", Some typeof<obj>)



    let parameters =
        [ ProvidedStaticParameter("Name", typeof<string>) ]

    do
        provider.DefineStaticParameters(parameters, createType)
        this.AddNamespace(ns, [ provider ])

[<assembly: TypeProviderAssembly>]
do()