public static YieldExpression MakeYield(LabelTarget target, Expression value, int yieldMarker)
{
ContractUtils.RequiresNotNull(target, "target");
ContractUtils.Requires(target.Type != typeof(void), "target", "generator label must have a non-void type");
if (value != null)
{
if (!TypeUtils.AreReferenceAssignable(target.Type, value.Type))
{
// C# autoquotes generator return values
if (target.Type.IsSubclassOf(typeof(Expression)) &&
TypeUtils.AreAssignable(target.Type, value.GetType()))
{
value = Expression.Quote(value);
}
throw new ArgumentException(string.Format("Expression of type '{0}' cannot be yielded to a generator label of type '{1}'", value.Type, target.Type));
}
}
return(new YieldExpression(target, value, yieldMarker));
}
public static NewArrayExpression NewArrayHelper(Type type, IEnumerable <Expression> initializers)
{
ContractUtils.RequiresNotNull(type, nameof(type));
ContractUtils.RequiresNotNull(initializers, nameof(initializers));
if (type.Equals(typeof(void)))
{
throw new ArgumentException("Argument type cannot be System.Void.");
}
ReadOnlyCollection <Expression> initializerList = initializers.ToReadOnly();
Expression[] clone = null;
for (int i = 0; i < initializerList.Count; i++)
{
Expression initializer = initializerList[i];
ContractUtils.RequiresNotNull(initializer, nameof(initializers));
if (!TypeUtils.AreReferenceAssignable(type, initializer.Type))
{
if (clone == null)
{
clone = new Expression[initializerList.Count];
for (int j = 0; j < i; j++)
{
clone[j] = initializerList[j];
}
}
if (type.IsSubclassOf(typeof(Expression)) && TypeUtils.AreAssignable(type, initializer.GetType()))
{
initializer = Expression.Quote(initializer);
}
else
{
initializer = Convert(initializer, type);
}
}
if (clone != null)
{
clone[i] = initializer;
}
}
if (clone != null)
{
initializerList = new ReadOnlyCollection <Expression>(clone);
}
return(Expression.NewArrayInit(type, initializerList));
}
