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

Pattern matching is one of those lovely features mostly found in functional programming languages like F#. There is a great project going on in codeplex named Functional C#. Consider the following F# code:

let operator x = match x with
                 | ExpressionType.Add -> "+"

let rec toString exp = match exp with
                       | LambdaExpression(args, body) -> toString(body)
                       | ParameterExpression(name) -> name
                       | BinaryExpression(op,l,r) -> sprintf "%s %s %s" (toString l) (operator op) (toString r)

Using the Functional C# library, the C# equivalent would be:

var Op = new Dictionary { { ExpressionType.Add, "+" } };

Expression> add = (x,y) => x + y;

Func toString = null;
 toString = exp =>
 exp.Match()
    .With(l => toString(l.Body))
    .With(p => p.Name)
    .With(b => String.Format("{0} {1} {2}", toString(b.Left), Op[b.NodeType], toString(b.Right)))
    .Return();