private static Expression CreateTupleSelector(
Expression body,
Expression[] memberSelectors)
{
Type[] memberTypes = memberSelectors.Select(e => e.Type).ToArray();
Type tupleType = TupleTypeHelper.CreateTupleType(memberTypes);
var helper = new TupleKeyInfoHelper(tupleType);
body = helper.CreateKeyFactoryExpression(memberSelectors);
return(body);
}
public void TupleKeyInfoHelper_KeyFactory()
{
TupleKeyInfoHelper builder = new TupleKeyInfoHelper(typeof(Tuple <int, string>));
Expression factory = builder.CreateKeyFactoryExpression(
Expression.Constant(1, typeof(int)),
Expression.Constant("2", typeof(string)));
var result = Expression.Lambda(factory).Compile().DynamicInvoke() as Tuple <int, string>;
Assert.IsNotNull(result);
Assert.AreEqual(1, result.Item1);
Assert.AreEqual("2", result.Item2);
}
public static LambdaExpression CreateMemberSelectorLambdaExpression(
Expression[] members,
params ParameterExpression[] parameters)
{
if (members.Length == 1)
{
return(Expression.Lambda(members[0], parameters));
}
else
{
Type[] tupleTypes = members.Select(m => m.Type).ToArray();
Type tuple = TupleTypeHelper.CreateTupleType(tupleTypes);
var helper = new TupleKeyInfoHelper(tuple);
return(Expression.Lambda(
helper.CreateKeyFactoryExpression(members),
parameters));
}
}
public void TupleKeyInfoHelper_KeyFactoryLarge()
{
TupleKeyInfoHelper builder =
new TupleKeyInfoHelper(typeof(Tuple <int, int, int, int, int, int, int, Tuple <int, int> >));
Expression factory = builder.CreateKeyFactoryExpression(
Enumerable
.Range(1, 9)
.Select(x => Expression.Constant(x, typeof(int)))
.ToArray());
var result = Expression.Lambda(factory).Compile().DynamicInvoke()
as Tuple <int, int, int, int, int, int, int, Tuple <int, int> >;
Assert.IsNotNull(result);
Assert.AreEqual(1, result.Item1);
Assert.AreEqual(2, result.Item2);
Assert.AreEqual(8, result.Rest.Item1);
Assert.AreEqual(9, result.Rest.Item2);
}