Expression helpers

ExpressionHelpers.cs

    using System;
    using System.Linq.Expressions;
    using System.Reflection;

    public static class ExpressionHelpers
    {
        public static T GetValue<T>(this Expression<Func<T>> source)
        {
            T unknownValue = source.Compile().Invoke();

            return unknownValue;
        }

        public static TProp GetValue<T, TProp>(this T source, Expression<Func<T, TProp>> property)
        {
            return property.Compile().Invoke(source);
        }

        public static string Name<T>(this Expression<Func<T>> target)
        {
            return (target.Body as MemberExpression).Member.Name;
        }

        public static string Name<T, TProp>(this T source, Expression<Func<T, TProp>> property)
        {
            return (property.Body as MemberExpression).Member.Name;
        }

        public static void SetValue<T, TProp>(this T target, Expression<Func<T, TProp>> property, TProp value)
        {
            var parms = new[] { property.Parameters[0], Expression.Parameter(typeof(TProp), "value") };

            var expression = Expression.Call(AssignmentHelper<TProp>.MethodInfoSetValue,
                                             new[] { property.Body, parms[1] });

            var lambda = Expression.Lambda<Action<T, TProp>>(expression, parms);

            var action = lambda.Compile();

            action(target, value);
        }

        private class AssignmentHelper<T>
        {
            internal static readonly MethodInfo MethodInfoSetValue =
                typeof(AssignmentHelper<T>).GetMethod("SetValue", BindingFlags.NonPublic | BindingFlags.Static);

            private static void SetValue(ref T target, T value)
            {
                target = value;
            }
        }
    }