2011-12-18 Failure of the dynamic keyword

2011-12-18 failure-of-the-dynamic-keyword

# Title: Failure of the dynamic keyword
# Author: Mikael Lundin
# Link: http://blog.mikaellundin.name/2011/12/18/failure-of-the-dynamic-keyword.html

DynamicMatch.cs

public class DynamicMatch : DynamicObject
{
    private readonly Match match;
 
    public DynamicMatch(Match match)
    {
        this.match = match;
    }
 
    public override bool TryGetMember(GetMemberBinder binder, out object result)
    {
        var prop = match.GetType().GetProperty(binder.Name);
 
        // Match instance property
        if (prop != null)
        {
            result = prop.GetValue(match, null);
            return true;
        }
 
        // Group value
        Group group;
        if ((group = this.match.Groups[binder.Name]) != null)
        {
            result = group.Value;
            return true;
        }
 
        result = null;
        return false;
    }
}

DynamicRegex.cs

public class DynamicRegex
{
    private readonly Regex expression;
    public DynamicRegex(string expression)
    {
        this.expression = new Regex(expression);
    }
 
    public dynamic Match(string input)
    {
        return new DynamicMatch(expression.Match(input));
    }
}

GetEmployee1.cs

private static object GetEmployee()
{
    return new { Name = "John", Profession = "Santa" };
}
 
object employee = GetEmployee();

GetEmployee2.cs

private static dynamic GetEmployee()
{
    dynamic employee = new { Name = "John", Profession = "Santa" };
    return employee;
}
 
var employee = GetEmployee();
Console.WriteLine("Employee of the month: {0}, {1}", employee.Name, employee.Profession);

Regex1.cs

string time = "12:00";
var match = Regex.Match(time, @"(?<Hour>\d{2}):(?<Minute>\d{2})");
if (match.Success)
{
    var hour = match.Groups["Hour"].Value;
    var minute = match.Groups["Minute"].Value;
    Console.WriteLine("The time is {0}.{1}", hour, minute);
}

Regex2.cs

string time = "12:00";
var match = new DynamicRegex(@"(?<Hour>\d{2}):(?<Minute>\d{2})").Match(time);
if (match.Success)
{
    Console.WriteLine("The time is {0}.{1}", match.Hour, match.Minute);
}