static void Main(string[] args)
{
var text = "Use expression trees";
Expression <Func <Cat, string> > sayMewExpression = cat => cat.SayMew(text);
List <string> list = new List <string>();
Stopwatch stopwatch = Stopwatch.StartNew();
for (int i = 0; i < OperationsCount; i++)
{
MethodCallExpression body = sayMewExpression.Body as MethodCallExpression;
Expression argument = body.Arguments[0];
// () => (object)test;
UnaryExpression converted = Expression.Convert(argument, typeof(object));
Expression <Func <object> > lambda = Expression.Lambda <Func <object> >(converted);
Func <object> func = lambda.Compile();
string value = func() as string;
list.Add(value);
}
Console.WriteLine($"{stopwatch.Elapsed} - Extracting using normal expression compiler");
list = new List <string>();
stopwatch = Stopwatch.StartNew();
for (int i = 0; i < OperationsCount; i++)
{
MethodCallExpression body = sayMewExpression.Body as MethodCallExpression;
Expression argument = body.Arguments[0];
// () => (object)test;
UnaryExpression converted = Expression.Convert(argument, typeof(object));
Expression <Func <object> > lambda = Expression.Lambda <Func <object> >(converted);
Func <object> func = lambda.CompileFast();
string value = func() as string;
list.Add(value);
}
Console.WriteLine($"{stopwatch.Elapsed} - Extracting using fast expression compiler");
list = new List <string>();
stopwatch = Stopwatch.StartNew();
for (int i = 0; i < OperationsCount; i++)
{
MethodCallExpression body = sayMewExpression.Body as MethodCallExpression;
Expression argument = body.Arguments[0];
MemberExpression arguemntMemeber = argument as MemberExpression;
ConstantExpression closureClassExpression = arguemntMemeber.Expression as ConstantExpression;
object closureClass = closureClassExpression.Value;
FieldInfo clasureClassFieldInfo = arguemntMemeber.Member as FieldInfo;
string value = (string)clasureClassFieldInfo.GetValue(closureClass);
list.Add(value);
}
Console.WriteLine($"{stopwatch.Elapsed} - Extracting with reflection");
list = new List <string>();
stopwatch = Stopwatch.StartNew();
for (int i = 0; i < OperationsCount; i++)
{
string value = NormalExpression.BuildExpression();
list.Add(value);
}
Console.WriteLine($"{stopwatch.Elapsed} - Building with normal expression");
list = new List <string>();
stopwatch = Stopwatch.StartNew();
for (int i = 0; i < OperationsCount; i++)
{
string value = FastExpression.BuildExpression();
list.Add(value);
}
Console.WriteLine($"{stopwatch.Elapsed} - Building with normal expression and using fast compile");
}
