Psychic Debugging, Part Two

re: Psychic Debugging, Part Two

Michael Giagnocavo — Thu, 06 Sep 2007 20:46:29 GMT

Yes, please do go into that. Especially how they interact with variable capture and so on. It's not too hard to be a bit careless and accidentally return an iterator that only works once, for instance.

re: Psychic Debugging, Part Two

Alex James — Fri, 07 Sep 2007 00:36:19 GMT

Eric

I understand the point you are making...

but correct me if I am wrong but there is absolutely no guarantee that the method is using yields at all...

i.e.

static public IEnumerable<Bar> GetBars(Foo foo) {

if (foo == null)

throw new ArgumentNullException("foo");

return SomeOtherClass.GetBars(foo);

I which case that means that the ArgumentNullException will get fired?

Alex

re: Psychic Debugging, Part Two

Eric Lippert — Fri, 07 Sep 2007 00:41:49 GMT

Correct.

re: Psychic Debugging, Part Two

Dean Harding — Mon, 10 Sep 2007 02:00:33 GMT

It'd probably be a good idea to do your parameter validation in a helper method that calls the "real" GetBars(). That way, you get the exception ASAP, rather than the first time you call MoveNext...

re: Psychic Debugging, Part Two

Mona — Tue, 18 Sep 2007 11:36:18 GMT

I am working with VB.NET, I have many mathematical equations in my windows application, which differ according to many options I selected from previous form. So I m using thesse equation as strings in database and according to the selected options from the previous form it drag the its equation, which I concatinate to a variable (number) according to the selected age. So this equation doesn't work because it defined as nvchar in the databse and the variable is number, I tried the function eval() which I use in asp to solve this but it didn't work. I want to know if there is a function in VB.NET can solve this problem or what can I do to solve it.

C# 4 idea: Iterator blocks and parameter checking

Jon Skeet: Coding Blog — Sun, 02 Mar 2008 22:54:47 GMT

Iterator blocks have an interesting property: they defer execution. When the method (or property) is