F# Class Library Template

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So, in my last post I said that the template would be the last for a while, but here is one more.

This template creates a Windows Library with a simple class definition. The template can be found on the Visual Studio Gallery:

https://visualstudiogallery.msdn.microsoft.com/a3f39bd9-9fd2-4465-a931-2163758a1447

When the template is installed you get the following template added to your F# folder when creating a new F# project:

image

This template also defines several Item Templates for creating the following project items:

  • F# Class – The definition of a simple F# class
  • F# Interface – The definition of a simple F# interface
  • F# Disposable Class – The definition of a F# class that implements IDisposable

The simple F# class generated code is as follows:

namespace FSharp.Library

open System;
open System.Xml;

type MyClass() as self =

    // https://msdn.microsoft.com/en-us/library/dd233205.aspx
    // TODO define your variables

    // TODO perform initialization code
    do
        ()

The F# interface definition is as follows:

namespace FSharp.Library

open System;

type MyInterface =

    // https://msdn.microsoft.com/en-us/library/dd233207.aspx
    // TODO define your abstract members

    abstract member MyMember: unit -> unit

The more interesting Item Template is the F# Class that implements the IDisposable Interface. This template provides the core code for dealing with both managed and unmanaged resources:

namespace FSharp.Library

open System;
open System.Xml;

type MyClass() as self =

    let mutable disposed = false;

    // https://msdn.microsoft.com/en-us/library/dd233205.aspx
    // TODO define your variables including disposable objects

    // TODO perform initialization code
    do
        ()

    // internal method to cleanup resources
    let cleanup(disposing:bool) =
        if not disposed then
            disposed <- true
            
            if disposing then
                // TODO dispose of managed resources
                ()

            // TODO cleanup unmanaged resources
            ()

    // implementation of IDisposable
    interface IDisposable with
        member self.Dispose() =
            cleanup(true)
            GC.SuppressFinalize(self)

    // override of finalizer
    override self.Finalize() =
        cleanup(false)

Using a class defined in this manner allows one to clean-up the class resources with a use binding.

Once again, hopefully you will find this template useful.

Written by Carl Nolan