CodingSeb.ExpressionEvaluator Functions

The CodingSeb.ExpressionEvaluator library provides many functions from System.Math which you can use directly in your expression or script.

The following example shows built-in functions which you can use directly.

public static void Example1()
{
    ExpressionEvaluator evaluator = new ExpressionEvaluator();

    List<string> expressions = new List<string>()
    {
        "Abs(-3.2d)",
        "Acos(-0.5d)",
        "Avg(1, 2.5, -4, 6.2)",
        "Floor(4.23d)",
        "IEEERemainder(9, 8)",
        "Log10(1000d)",
    };

    foreach (var expr in expressions)
    {
        var result = evaluator.Evaluate(expr);
        Console.WriteLine($"{expr} \n\t {result}\n");
    }
}

Let's execute the above code, and you will see the following output.

Abs(-3.2d)
         3.2

Acos(-0.5d)
         2.0943951023931957

Avg(1, 2.5, -4, 6.2)
         1.425

Floor(4.23d)
         4

IEEERemainder(9, 8)
         1

Log10(1000d)
         3

You can also add an extension method for the evaluation. For example, let's suppose we have a simple string extension method as shown below.

public static class StringExtendedMethods
    {
        public static string AddExtended(this string str)
        {
            return str + " extended";
        }
    }

To use extension methods Expression Evaluator need to know which classes implement extension methods.

• Expression Evaluator do not find extension methods by itself because depending on the size of your assembly, it can be very slow.
• But if you want, you can use StaticTypesForExtensionsMethods list as shown below.

public static void Example2()
{

    ExpressionEvaluator evaluator = new ExpressionEvaluator(new Dictionary<string, object>()
    {
        { "str", "Samle string" }
    });

    evaluator.StaticTypesForExtensionsMethods.Add(typeof(StringExtendedMethods));

    List<string> expressions = new List<string>()
    {
        "str.AddExtended()",
    };

    foreach (var expr in expressions)
    {
        var result = evaluator.Evaluate(expr);
        Console.WriteLine($"{expr} \n\t {result}\n");
    }
}

Let's execute the above code, and you will see the following output.

str.AddExtended()
         Samle string extended