Even if I don't feel completely enlightened, I'm quite pleased that this has crystalized for me exactly why I struggle to understand these concepts.

Firstly, I often don't know if a particular statement is to be accepted axiomatically, or whether I should be able to deduce it myself based on information presented earlier together with my own logic and intuition. For example the bit about [paraphrasing] "...if there is a demand for an 'A' and with resources 'R' we can satisfy the demand, we can transform it so that there is now an 'I.O.U(A)' together with the resource 'R' and now there is no longer a demand for 'A'...". And the bit about it going back the other way. Are such statements axioms or logical conclusions (or other).

Second, and to a lesser degree, when it gets down to the very fundamental stuff, I sometimes struggle to understand what I have 'in hand'.

• Truth: Is set 'A' equal in size to set 'B'?
• Me: Sure, I count 3 elements in set 'A' and 3 elements in set 'B'. They're the same size.
• Truth:You can't count them.
• Me: What? Why?
• Truth:Because you don't have numbers.
• Me: Huh?
• Truth:See, it's easy, there's this function 'f' defined 'blah blah blah' that is a bijection between set 'A' and set 'B', so...
• Me: So I have sets and functions, but not numbers?
• Truth:Right.
• Me: Oh.

Even if I didn't completely understand it, I did quite enjoy it. I like the feeling that enlightenment is within reach. Thanks, and looking forward to part 4.

posted by dpratt71

Otherwise, the lecture was great.  Thanks!

P.S. Greg could only make it up to me if for part 4 of the series, the same laptop goes through a grinder in the background

posted by s0ftimage

First of all, Greg is not a Microsoft employee. Second, this technical series is not a product advertisement.... Spend time watching and listening to what Greg is saying. You can get over the fact that he uses a Mac (he also uses a PC running Windows 7) since it has nothing to do with the topics being introduced and explained to you. We're lucky to have Greg Meredith take the time to teach us about monadic design principles. Please don't detract from what really matters here.

Channel 9 should be a place that welcomes diversity in all of its forms. We are not an advertisement channel. We want to provide a welcoming place for folks who aren't part of the MS community and ensure that they too can get some real value from our technical content and engage with fellow developers/enthusiasts in the C9 forums.

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posted by Charles

Great series so far, I like it very much. Greg really has a way of making this stuff enjoyable and I hope there will be more Monty Python references in the future talks.

I have a question on the intuition behind the 'redeem'-rule: The way I understand it, an IOU(A) can be understood as a 'promise' for an A. We do not know if we can keep this promise, so it's treated as not(A) by default. Now what the redeem rule says is, that if I can wrap a A inside IOU, I can do the same thing with IOU(A), creating IOU(IOU(A)) in the process. What I don't understand is how it is enforced that I can only redeem this IOU(IOU(A)) if I have an A? In the end, a plain IOU(A) is practically worth nothing. Since there is no Gold-Standard to back it up, it does not make sense that I am able to redeem it for an A just like that, does it?

I'd be glad if you could elaborate on that a little more.

Thanks!

posted by ComicSansMS

I just had to mention this because seeing your previous videos, and seeing how clear you could have made this, you are far better than this for teaching people.  
Maybe you shoud try to bite-size the reproduction methods and therory into a prelude to the examples you intend to give.  
I just feel bad for the person above (and future others) admitting defeat to these as well as giving up on even attempting to understand the rationale, don't you?

posted by HeavensRevenge

Also I notice Greg use the word "cool" a lot, to me this suggest they are thinking and trying too hard to be cool. 

SeaJUG June 2009: Monads

posted by AdamSpeight2008

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posted by Charles

On this occasion maybe Brian Beckman should have sat in on this one, as I think Greg would have more confident. They seem to have a good chemistry together.

posted by AdamSpeight2008

7 hours ago, Adam​Speight2008 wrote

No problem @Charles: you still the thinking man's idiot...

Hmm. Not sure I like the terminology... Only I can call myself an idiot in any context. Certainly, this is true when I am in the same room with the likes of Bill Gates, Erik Meijer, Brian Beckman, Greg Meredith, Mark Russinovich, Wolfram Schulte, Anders Hejlsberg, Patrick Dussud, etc.

No worries. I understand what you were trying to say. I am a generalist and as such will always ask general questions of the experts in frame. In this case, a lecture, I asked no questions. Just listened and learned(and maybe screwed up the lecture flow before the camera rolled...).

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posted by Charles

The last thing which I remembered just now is that Greg always had this habit of checking his time, and not just "what time is it" time, but the "omg i need to go faster or ill never finish" time.  
I don't know if thats just something specific to his character or some other reason, but he might have a more passionate explination of content if he wasn't stressing out on trying to keep the lecture on good caidance.
Just wanted to bring this to his attention, as it is noticable and might be pulling him off his refined professor groove a little.

posted by HeavensRevenge

In the future, I will book more time and Greg will just do his thing. If I can get Beckman in the room, then there will be great questions along the way as Adam suggested (great idea and I would love to do this, but Brian is cranking code and doesn't have time right now. This will not always be the case, of course. Erik? He's found yet another categorical gem and is actively writing the math that defines it in such a way as to make it useful for developers. You know, what he does for a living.)

Thanks for the kind words (though I am not working behind enemy lines... I am inside the machine showing you how the sausage is made and introducing you to the passionate and capable humans behind our software - Microsoft has a caramel sweet center and I hope this is made clear in the work we do on Channel 9).

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posted by Charles

Thanks Charles

posted by s0ftimage

I agree with the comments that this version seemed to make things much more confusing than they actually were.  I kept thinking I must be missing the important part.  But by the end I was pretty sure it was just a really complicated way of presenting a logically simple (to me) concept.  I admit though that there may be more to it that I thought, since I don't know where this is headed yet (it becomes more clear once the pieces start to come together a little).  Maybe more preview of where we are headed in the beginning would have helped.

In any case, i'm looking forward to the upcoming part(s). Thanks again to Greg and Charles for doing these shows.

(I'm sure you have your reasons for the episode timing, but having episodes closer together would help understanding as well, since you would forget less of what happened last time.)

posted by ryanb

Two comments:

a) I think it would help to have a touch screen or something so that when the presenter 'points' to the screen, the pointer can be recorded in the screen capture as well.

b) Greg looks like he has been working way too hard. My suggestion is the have him in check into the nearest day spa for a full day of pamering. Go ahead Greg you have our permission.

posted by fwaris

Sounds like this key-value database algorithm to go back in time to resolve transactions is NP-complete, so I wonder if it really works in a large bank.

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That A => IOU(IOU(A)) will not guarantee IOU(IOU(A)) => A, can be seen with the type system: The input and output types of the function "=>" will be different.

Speaking of types... Lecture's description of programming language hits some pain points of C#:

interface ProgrammingLanguage 
{  
 IEnumerable<Command> Keywords<Command>() where Command : Func<Command, Command>;
}

where the actual Command should be an option type of Func, Action or a Type, right?

posted by Thorium

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