public override DynamicMetaObject BindDeleteMember(DeleteMemberBinder binder)
{
ContractUtils.RequiresNotNull(binder, "binder");
int index = Value.Class.GetValueIndex(binder.Name, binder.IgnoreCase, Value);
Expression tryDelete = Expression.Call(
typeof(RuntimeOps).GetMethod("ExpandoTryDeleteValue"),
GetLimitedSelf(),
Expression.Constant(Value.Class, typeof(object)),
Expression.Constant(index),
Expression.Constant(binder.Name),
Expression.Constant(binder.IgnoreCase)
);
DynamicMetaObject fallback = binder.FallbackDeleteMember(this);
DynamicMetaObject target = new DynamicMetaObject(
Expression.IfThen(Expression.Not(tryDelete), fallback.Expression),
fallback.Restrictions
);
return(AddDynamicTestAndDefer(binder, Value.Class, null, target));
}
/// <summary>
/// Provides the implementation of deleting a member. Derived classes can override
/// this method to customize behavior. When not overridden the call site requesting the
/// binder determines the behavior.
/// </summary>
/// <param name="binder">The binder provided by the call site.</param>
/// <returns>true if the operation is complete, false if the call site should determine behavior.</returns>
public virtual bool TryDeleteMember(DeleteMemberBinder binder)
{
return(false);
}
/// <summary>
/// Performs the binding of the dynamic delete member operation.
/// </summary>
/// <param name="binder">An instance of the <see cref="DeleteMemberBinder"/> that represents the details of the dynamic operation.</param>
/// <returns>The new <see cref="DynamicMetaObject"/> representing the result of the binding.</returns>
public virtual DynamicMetaObject BindDeleteMember(DeleteMemberBinder binder)
{
ContractUtils.RequiresNotNull(binder, "binder");
return(binder.FallbackDeleteMember(this));
}
