Implementing pattern matching in C#

Question

In Scala, you can use pattern matching to produce a result depending on the type of the input. For instance:

val title = content match {
    case blogPost: BlogP         


        

Answer 1

In order to ensure total pattern matching, you would need to build the function into the type itself. Here's how I'd do it:

public abstract class Content
{
    private Content() { }

    public abstract T Match(Func convertBlog, Func convertPost);

    public class Blog : Content
    {
        public Blog(string title)
        {
            Title = title;
        }
        public string Title { get; private set; }

        public override T Match(Func convertBlog, Func convertPost)
        {
            return convertBlog(this);
        }
    }

    public class BlogPost : Content
    {
        public BlogPost(string title, Blog blog)
        {
            Title = title;
            Blog = blog;
        }
        public string Title { get; private set; }
        public Blog Blog { get; private set; }

        public override T Match(Func convertBlog, Func convertPost)
        {
            return convertPost(this);
        }
    }

}

public static class Example
{
    public static string GetTitle(Content content)
    {
        return content.Match(blog => blog.Title, post => post.Blog.Title + ": " + post.Title);
    }
}