WEBVTT 00:00:07.729 --> 00:00:10.219 >> Hello and welcome to the Haskell Weekly podcast. 00:00:10.400 --> 00:00:12.129 I'm your host, taylor Fausak. 00:00:12.290 --> 00:00:15.200 I'm the Director of Software Engineering at ACI Learning. 00:00:15.800 --> 00:00:19.400 With me today is Cameron Gera, one of the engineers on my team. 00:00:19.640 --> 00:00:21.020 Thanks for joining me today, Cam. 00:00:21.650 --> 00:00:22.610 >> Thanks for having me, Taylor. 00:00:22.610 --> 00:00:25.040 I'm excited to get back to some podcasting. 00:00:25.430 --> 00:00:27.110 Uh, today we've got a fun topic. 00:00:27.170 --> 00:00:32.535 I think it's, uh, A little bit on the void side of Haskell. 00:00:32.685 --> 00:00:37.215 Um, actually the, the article was called the voids of Haskell by Alexander 00:00:37.215 --> 00:00:41.895 Granin, uh, who is the author of functional design and architecture. 00:00:42.195 --> 00:00:46.755 Um, and generally to kind of start out this article is very much 00:00:46.755 --> 00:00:49.725 like Haskell is great and it's getting better, but there's still 00:00:49.725 --> 00:00:50.505 something missing. 00:00:50.505 --> 00:00:54.435 And there's this void in Haskell and that's, you know, the big idea of 00:00:54.435 --> 00:00:55.395 what we're going to talk about today. 00:00:56.110 --> 00:00:56.320 >> Yeah. 00:00:56.320 --> 00:01:01.180 So, uh, he says the voids and implying there's more than one, 00:01:01.180 --> 00:01:03.220 but what are the voids that he's talking about? 00:01:04.175 --> 00:01:08.285 >> Um, the voids that he's talking about mostly are the voids 00:01:08.315 --> 00:01:15.274 in the book world related to Haskell and the various design patterns, 00:01:15.274 --> 00:01:19.984 the various thought processes, the various design choices you can make. 00:01:20.374 --> 00:01:21.984 And, uh, I think. 00:01:22.320 --> 00:01:26.220 He actually lays out a really good list of books that would be really nice to have. 00:01:26.550 --> 00:01:30.119 And so I think we're going to cover a couple of those today, uh, and, you know, 00:01:30.840 --> 00:01:35.820 give somebody more of a practical resource instead of, you know, a blog post, which 00:01:35.850 --> 00:01:40.320 blog posts can help you with stuff, but it doesn't give you the big picture of the 00:01:40.320 --> 00:01:47.300 language and how it relates to the larger, you know, intricacy of the language, 00:01:47.330 --> 00:01:49.490 because there's things in Haskell that. 00:01:50.205 --> 00:01:53.804 A lot of languages don't necessarily have, and there's a strong type 00:01:53.804 --> 00:02:00.435 system that allows you to do and program in a way that doesn't 00:02:00.435 --> 00:02:02.085 allow mistakes to happen and stuff. 00:02:02.085 --> 00:02:05.685 So, um, I think pretty excited about the books we're going to talk about 00:02:05.714 --> 00:02:07.695 today as far as possible books. 00:02:07.695 --> 00:02:11.355 So for any of our listeners find any of these really interesting. 00:02:11.955 --> 00:02:15.915 Or you guys read the article yourself, you know, to try to tackle it, see 00:02:15.915 --> 00:02:17.265 what you see if you can make that book. 00:02:17.295 --> 00:02:20.025 Because for me personally, I'm not sure what would, what would it 00:02:20.085 --> 00:02:21.105 take to make a book? 00:02:21.495 --> 00:02:22.655 Um, what would it make? 00:02:22.725 --> 00:02:23.234 What would it 00:02:23.234 --> 00:02:24.185 take for you, Taylor? 00:02:24.204 --> 00:02:24.554 You think? 00:02:24.605 --> 00:02:24.665 Yeah. 00:02:25.120 --> 00:02:29.020 >> uh, for me to write a book, I would need. 00:02:29.855 --> 00:02:33.215 No job, I guess it would take a lot of time. 00:02:34.144 --> 00:02:36.424 Um, but beyond that, I don't know. 00:02:36.424 --> 00:02:37.774 I've never tried to write a book either. 00:02:37.774 --> 00:02:38.975 I've written blog posts. 00:02:39.005 --> 00:02:44.765 And as you mentioned, blog posts, can't go into the same amount of detail as a book. 00:02:45.304 --> 00:02:46.535 And sometimes that's fine. 00:02:46.535 --> 00:02:47.885 You know, you can have a really. 00:02:48.334 --> 00:02:51.755 Precise point you're trying to make or an example. 00:02:52.204 --> 00:02:57.864 Um, but sometimes it's more useful to have the full worked end to end example, 00:02:57.885 --> 00:03:01.595 that good gets into all the little caveats and the things you actually have to 00:03:01.595 --> 00:03:05.554 worry about when you're doing something that's not just a demo or something 00:03:05.554 --> 00:03:06.875 you're showing off for a blog post. 00:03:07.685 --> 00:03:12.545 And, um, one of the things I like about what Alexander did here with his posts, 00:03:12.935 --> 00:03:15.935 It is, he gave a lot of options, right? 00:03:15.935 --> 00:03:19.535 There's like 20 something blog or sorry, book topics. 00:03:20.225 --> 00:03:24.665 So he's casting a wide net and there's lots of different 00:03:24.665 --> 00:03:25.955 people in the Haskell community. 00:03:25.955 --> 00:03:30.935 And I think there is a lot of potential for good stuff to come out of this. 00:03:31.804 --> 00:03:32.225 >> Yeah. 00:03:32.225 --> 00:03:36.575 And I, and I, as you kind of pointed to blog posts being pretty limited in scope. 00:03:36.845 --> 00:03:40.475 When you have a textbook, you can generally reference the previous chapters 00:03:40.475 --> 00:03:45.005 where you said, remember in chapter five, when we talked about this, well, here's. 00:03:45.235 --> 00:03:48.805 Why that was important, um, because it impacts chapter seven. 00:03:48.835 --> 00:03:54.325 So the relationships between concepts are much easier to represent in a 00:03:54.325 --> 00:03:58.795 textbook rather, or a more verbose book than a blog post, because it doesn't 00:03:58.795 --> 00:04:02.065 necessarily have to be a textbook, but you know, a handbook, you know, we have 00:04:02.095 --> 00:04:06.445 learned you a Haskell, which is just kind of a step-by-step guide basic. 00:04:06.960 --> 00:04:08.310 Principals of high school. 00:04:08.580 --> 00:04:12.450 Um, and they do a lot of like referencing to previous chapters of 00:04:12.450 --> 00:04:13.470 the book and stuff like that. 00:04:13.470 --> 00:04:16.920 So, um, that's another great benefit of books. 00:04:17.404 --> 00:04:18.334 >> That's a really good point. 00:04:18.454 --> 00:04:21.274 And you can pull that off with blog posts, you know, like, 00:04:21.305 --> 00:04:22.685 oh, this is part of a series. 00:04:22.685 --> 00:04:25.325 Go read the previous posts if you want to find out more. 00:04:25.745 --> 00:04:29.344 But more generally I think blog posts are intended to be like 00:04:29.344 --> 00:04:31.205 a drive by resource either. 00:04:31.534 --> 00:04:35.465 It's something that is approachable enough where you can have the whole 00:04:35.465 --> 00:04:40.414 thing self-contained, or it's a deep dive on some really niche topic. 00:04:40.445 --> 00:04:40.955 So. 00:04:41.690 --> 00:04:45.440 Only people that are already interested in that are going to seek it out and they'll 00:04:45.440 --> 00:04:46.970 already have all the requisite knowledge. 00:04:47.725 --> 00:04:48.145 >> right. 00:04:48.205 --> 00:04:48.534 Yeah. 00:04:48.595 --> 00:04:51.625 And you know, back to the point of why he. 00:04:52.100 --> 00:04:56.850 Was kind of saying there's a void here or there's voids here in Haskell is a lot 00:04:56.850 --> 00:05:00.870 of the other mainstream languages have a lot of textbooks and a lot of books 00:05:00.870 --> 00:05:05.160 that reference various concepts, design patterns, and, you know, architecture 00:05:05.160 --> 00:05:08.130 choices that people can use and pick up. 00:05:08.130 --> 00:05:11.280 And, you know, there's some for the functional languages, but a lot of them 00:05:11.280 --> 00:05:13.200 are for the object oriented languages. 00:05:13.200 --> 00:05:18.540 So when Haskell can create these books, it creates an open door 00:05:18.540 --> 00:05:20.220 for the functional paradigm to. 00:05:20.535 --> 00:05:21.375 Kind of move in. 00:05:21.825 --> 00:05:25.635 Um, you know, I know overall the funk programming world is moving 00:05:25.635 --> 00:05:29.595 more functional, you know, there's functional, JavaScript, whatever that is. 00:05:29.955 --> 00:05:33.165 And, you know, there's all kinds of different stuff. 00:05:33.195 --> 00:05:36.345 That's moving, you know, different object oriented programming languages 00:05:36.345 --> 00:05:40.845 that are implementing functional design choices, uh, because it's intuitive. 00:05:40.845 --> 00:05:45.345 It's, you know, Easy for people who have been learning math and it's 00:05:45.345 --> 00:05:48.585 kindergarten, you know, where you learn, you pick up some algebra. 00:05:48.645 --> 00:05:49.125 Oh, okay. 00:05:49.125 --> 00:05:50.565 Here's how these things relate. 00:05:50.595 --> 00:05:54.765 Here's how, you know, I pass my function. 00:05:54.765 --> 00:05:56.115 I'm going to pass to another function. 00:05:56.535 --> 00:05:57.975 Well, it's going to evaluate and give you a 00:05:57.975 --> 00:05:58.395 result. 00:05:58.425 --> 00:05:59.025 That's great. 00:05:59.325 --> 00:06:02.115 Um, and you, and you'll know more or less what's happening. 00:06:03.289 --> 00:06:03.679 >> Yeah. 00:06:03.979 --> 00:06:09.169 And, uh, you know, another, uh, another angle of this, I think that would be 00:06:09.169 --> 00:06:14.090 interesting to explore is how many papers have been written in or about Haskell? 00:06:14.359 --> 00:06:19.039 Cause you know, it has kind of academic roots and a lot of the things that 00:06:19.039 --> 00:06:23.960 people do with GHC to add new stuff to it are part of their PhD thesis. 00:06:23.989 --> 00:06:25.460 So they ended up writing a paper for it. 00:06:25.939 --> 00:06:29.030 I would, I would bet that Haskell has more papers. 00:06:29.359 --> 00:06:31.729 Than most other languages, maybe any other language. 00:06:32.090 --> 00:06:36.409 Um, but clearly those are not as valuable of a resource for what 00:06:36.440 --> 00:06:39.200 Alexander points out in here of like a day to day, you know, 00:06:39.210 --> 00:06:41.359 practitioner more so than a researcher. 00:06:41.810 --> 00:06:44.419 And that's what he seems to have focused on with these topics. 00:06:45.090 --> 00:06:45.450 >> Right. 00:06:45.450 --> 00:06:49.910 And I think to the, some of the people who may have interest in Haskell kind 00:06:49.910 --> 00:06:54.440 of shy away from using it in production, because it's got such a research 00:06:54.440 --> 00:06:58.935 heavy background and, you know, People may feel like, oh, this is only good 00:06:58.935 --> 00:07:04.995 for compiling results and, you know, enhancing minor speed changes or whatever. 00:07:04.995 --> 00:07:09.885 Cause as you get know, as hassle gets more and more contributed to there's 00:07:09.885 --> 00:07:15.935 more of, uh, you know, I guess, or in the academic sense, there's 00:07:15.935 --> 00:07:18.215 less like major changes happening. 00:07:18.615 --> 00:07:21.885 On the academic side, it's just like one little thing or one. 00:07:22.095 --> 00:07:22.485 And so 00:07:23.505 --> 00:07:24.675 I'm curious if commercial 00:07:24.675 --> 00:07:28.845 Haskell's really kind of shut conventional Haskell uses shied 00:07:28.845 --> 00:07:29.805 away from because of that. 00:07:30.775 --> 00:07:33.655 >> Would be, um, and you know, major changes I think are 00:07:33.655 --> 00:07:35.155 still happening, like linear 00:07:35.155 --> 00:07:38.185 Haskell, or even dependent types making its way in. 00:07:38.735 --> 00:07:44.284 Um, and I just want to point out that like, for us at it pro slash 00:07:44.344 --> 00:07:50.165 ACI, um, we are, we shy away from the research heavy stuff, but we still 00:07:50.165 --> 00:07:53.795 use Haskell and it's been a boon for our engineering organization. 00:07:54.005 --> 00:07:59.195 So even if you're just doing normal, you know, HTTP, API stuff, 00:07:59.285 --> 00:08:00.455 Haskell works great for that. 00:08:01.325 --> 00:08:02.315 >> Yeah, it really does. 00:08:02.315 --> 00:08:05.285 And I think, you know, he points to that in his kind of introduction 00:08:05.285 --> 00:08:10.175 to this post of, you know, Haskell is a really good tool. 00:08:10.775 --> 00:08:11.075 Yes. 00:08:11.075 --> 00:08:14.555 It may have higher overhead to learn in the beginning, 00:08:14.675 --> 00:08:18.185 but the velocity you gain at the end of the day is much greater 00:08:18.185 --> 00:08:20.195 than the time lost in learning it. 00:08:21.805 --> 00:08:24.354 >> So I think we've set the table pretty well here. 00:08:24.445 --> 00:08:26.484 Uh, do you want to dig into some of these book 00:08:26.484 --> 00:08:27.145 topics? 00:08:27.650 --> 00:08:27.920 >> Yeah. 00:08:27.920 --> 00:08:30.830 I mean, we've got a whole entire, a feast 00:08:30.830 --> 00:08:32.990 hero of topics to choose from as well. 00:08:32.990 --> 00:08:37.820 You know, I think it's, I mean, we have more options and Thanksgiving day, you 00:08:37.940 --> 00:08:38.330 >> Yeah. 00:08:38.330 --> 00:08:39.380 So where should we start? 00:08:39.440 --> 00:08:40.310 What's our appetizer. 00:08:40.670 --> 00:08:43.310 >> um, well, I I'd like to touch on one that. 00:08:44.055 --> 00:08:48.675 I think it's a very interesting one and something that's a little more hidden. 00:08:48.675 --> 00:08:51.555 We've actually talked about it on the Haskell weekly podcast before. 00:08:51.975 --> 00:08:56.415 Um, but it's a book called gain development in Haskell. 00:08:56.655 --> 00:08:58.125 Wouldn't that be a nice thing to have? 00:08:58.515 --> 00:09:00.885 You know, you can take it, you can see, oh, Hey, I can 00:09:00.885 --> 00:09:03.675 make a, you know, a 2d game. 00:09:03.705 --> 00:09:05.025 This is how this works. 00:09:05.055 --> 00:09:05.535 Okay. 00:09:05.535 --> 00:09:07.065 Well, you know, cause. 00:09:07.755 --> 00:09:09.015 I mean, those are kind of fun. 00:09:09.015 --> 00:09:10.965 They're, they're an easy way to get in. 00:09:10.995 --> 00:09:11.355 Right. 00:09:11.355 --> 00:09:16.725 So like, you know, it's a perfect way for a teenage person to be like, oh 00:09:16.725 --> 00:09:18.315 yeah, I want to make a game for myself 00:09:18.315 --> 00:09:18.495 that I 00:09:18.495 --> 00:09:19.035 can play. 00:09:19.485 --> 00:09:20.205 Well, okay. 00:09:20.205 --> 00:09:20.685 Hey, here's 00:09:20.685 --> 00:09:22.605 this game development Haskell. 00:09:22.965 --> 00:09:23.985 Everybody loves games. 00:09:24.015 --> 00:09:24.675 So why not? 00:09:25.705 --> 00:09:26.665 >> Yeah, I agree. 00:09:26.665 --> 00:09:29.425 I think this would be a great kind of starter topic. 00:09:29.425 --> 00:09:31.105 And one of the reasons I think that is that. 00:09:31.595 --> 00:09:39.035 For a library like gloss or, um, even SDL, but more so gloss, uh, you can start with 00:09:39.064 --> 00:09:43.865 nothing and pretty quickly have something interactive up on your screen, like 00:09:43.895 --> 00:09:47.944 visually interactive, where you can click on stuff with your mouse and see it react. 00:09:48.515 --> 00:09:54.485 And that to me, I think is a lot more, um, motivating then like 00:09:54.485 --> 00:09:56.035 writing a command line program that. 00:09:57.035 --> 00:10:01.055 I don't know, does something, but a game with it's instant feedback 00:10:01.085 --> 00:10:04.325 is really rewarding to see the progress you made were like, oh, I 00:10:04.325 --> 00:10:05.615 want to change how that thing looks. 00:10:05.615 --> 00:10:07.535 I'll make the change over here and then bring it up and, 00:10:07.565 --> 00:10:08.465 oh, look, it's different now. 00:10:08.495 --> 00:10:09.875 I made that change happen. 00:10:09.995 --> 00:10:10.655 That feels good. 00:10:11.465 --> 00:10:12.905 >> Yeah, that's what I liked to do. 00:10:13.045 --> 00:10:17.135 And with Alan, cause it's that front end language that allows you to see 00:10:17.135 --> 00:10:19.535 the result of your change quickly. 00:10:19.745 --> 00:10:22.145 Um, it interacts with the code you 00:10:22.145 --> 00:10:26.975 wrote rather than be like, it's doing something back there, um, in the 00:10:26.975 --> 00:10:28.775 back end, but I'm not really sure. 00:10:29.735 --> 00:10:30.095 >> Yeah. 00:10:30.895 --> 00:10:32.365 Um, so unfortunately neither 00:10:32.365 --> 00:10:34.405 of us are game developers. 00:10:34.465 --> 00:10:39.235 Uh, last time on the podcast when this was a topic, Dustin and Cody 00:10:39.235 --> 00:10:41.995 were talking about it, and Dustin has some experience with game development. 00:10:41.995 --> 00:10:45.535 So I'd be curious, uh, you know, he may be a good candidate for writing 00:10:45.895 --> 00:10:47.575 a book about game development. 00:10:47.575 --> 00:10:48.835 Haskell we'll have to bug him about that. 00:10:50.045 --> 00:10:50.225 >> yeah, 00:10:50.225 --> 00:10:53.075 I'll make it part of his, uh, annual review process. 00:10:54.005 --> 00:10:55.775 Hey man, I got this great goal for you, 00:10:55.775 --> 00:10:56.105 man. 00:10:56.105 --> 00:10:58.745 I think you should write a book called game day. 00:10:58.845 --> 00:11:03.435 Well in Haskell, you'll make hundreds, 00:11:03.635 --> 00:11:05.225 >> You'll make hundreds of dollars. 00:11:06.015 --> 00:11:10.605 >> I can't guarantee thousands or millions, but you know, hundreds, 00:11:10.640 --> 00:11:10.940 >> Yeah. 00:11:11.925 --> 00:11:12.315 >> you know, 00:11:12.560 --> 00:11:13.670 >> but yeah, I don't have much else to 00:11:13.670 --> 00:11:15.020 say about game development. 00:11:15.020 --> 00:11:15.950 I think it would be great. 00:11:15.980 --> 00:11:16.940 And I would love to see it. 00:11:16.970 --> 00:11:19.310 And I've tried to write some tiny games in high school. 00:11:19.310 --> 00:11:22.010 So, I mean, maybe I should write the book, but I think I wrote 00:11:22.010 --> 00:11:23.150 blog posts about them at the time. 00:11:23.150 --> 00:11:24.440 So I'm doing my part. 00:11:26.040 --> 00:11:26.220 >> Yeah. 00:11:26.670 --> 00:11:28.260 It's not enough to tell her we need more. 00:11:29.660 --> 00:11:30.050 Yeah. 00:11:30.080 --> 00:11:33.350 I mean, we don't want you to quit, so you, you're not allowed to write a book. 00:11:34.490 --> 00:11:36.860 You already said you have to quit your job and that's not okay. 00:11:38.330 --> 00:11:38.750 We'd be. 00:11:39.005 --> 00:11:40.315 >> I protected myself there. 00:11:40.945 --> 00:11:46.045 So, so the ne the next potential book topic we could talk about, uh, it's 00:11:46.045 --> 00:11:49.915 a little closer to home for us is test-driven development in Haskell. 00:11:50.425 --> 00:11:52.315 And I think we probably talked about testing before. 00:11:52.315 --> 00:11:55.885 I don't think we've had an entire episode devoted to it, but it comes up 00:11:55.885 --> 00:11:57.475 a lot as a topic here on the podcast. 00:11:58.765 --> 00:11:59.125 >> Yeah. 00:11:59.235 --> 00:11:59.565 Yeah. 00:11:59.565 --> 00:12:02.895 I mean, test driven development is a big. 00:12:04.035 --> 00:12:06.255 Big thing around the software industry. 00:12:06.255 --> 00:12:06.675 Right. 00:12:06.735 --> 00:12:11.535 You know, anytime you go for a coding interview or you read a job posting 00:12:11.535 --> 00:12:14.175 it's oh, are you familiar with TDD? 00:12:14.565 --> 00:12:18.195 Um, and generally they're meaning test driven development. 00:12:18.225 --> 00:12:20.865 There's other TBDs that we'll get to later actually. 00:12:21.285 --> 00:12:26.755 Um, but they're talking about this concept of, you know, red, green refactoring and, 00:12:26.755 --> 00:12:30.675 and you know, the big names in Haskell or in the programming world, you know, 00:12:30.705 --> 00:12:32.925 Martin Fowler, all those guys have. 00:12:33.570 --> 00:12:36.900 Written and talked about why test driven fellow it's important. 00:12:37.620 --> 00:12:43.950 And, you know, with Haskell being, you know, quote unquote academic, 00:12:44.430 --> 00:12:47.640 I think people tend to not really worry about test driven development. 00:12:47.640 --> 00:12:49.860 They're more worried about the results. 00:12:49.950 --> 00:12:52.980 And so we haven't seen that from the academic side. 00:12:53.040 --> 00:12:54.960 Maybe I could be wrong, but. 00:12:55.845 --> 00:12:59.615 You know, when you're writing a day-to-day application and something that you're 00:12:59.615 --> 00:13:04.805 supposed to maintain longterm, um, you know, having a book for test different 00:13:04.805 --> 00:13:08.525 development Haskell would be really helpful to, you know, understand 00:13:08.945 --> 00:13:13.445 first of all, like the semantics of testing and at school, uh, really kind 00:13:13.445 --> 00:13:19.175 of understanding and clarifying the types of tests within Haswell, right. 00:13:19.175 --> 00:13:20.885 Property unit. 00:13:21.185 --> 00:13:23.405 Uh, integration, all those kinds of things. 00:13:23.405 --> 00:13:25.955 You know, you want to kind of expand upon those and how they relate. 00:13:26.285 --> 00:13:30.815 Um, and also it'd be nice to kind of know how, you know, test driven 00:13:30.815 --> 00:13:34.535 development works for various like 00:13:35.675 --> 00:13:37.115 frameworks or, 00:13:37.475 --> 00:13:43.145 you know, um, things we'll just say libraries. 00:13:44.680 --> 00:13:45.010 >> Yeah. 00:13:45.010 --> 00:13:49.150 I think there's a huge breadth of topics that could be addressed in a 00:13:49.150 --> 00:13:49.900 book like this. 00:13:49.900 --> 00:13:53.560 Like you mentioned, just the different types of testing. 00:13:53.925 --> 00:13:55.175 Would be interesting to cover. 00:13:55.385 --> 00:13:59.405 And then from there you can springboard into, these are the libraries that can 00:13:59.405 --> 00:14:03.845 provide, you know, frameworks to write tests of this type in, or that type. 00:14:03.875 --> 00:14:07.265 And here's why you may prefer this library over that library. 00:14:07.745 --> 00:14:11.345 Um, I think most people reach for like H spec, but as a 00:14:11.345 --> 00:14:12.815 beginner, you may not know that. 00:14:12.905 --> 00:14:15.935 And as an intermediate person, you may not know. 00:14:16.655 --> 00:14:19.475 What alternatives are there and why may you want to use one of them? 00:14:20.195 --> 00:14:23.855 Um, and similarly touching on like integration testing in particular, 00:14:24.005 --> 00:14:28.925 um, you know, if you follow the reader, Tio or Rio, um, kind of 00:14:28.925 --> 00:14:31.235 framework, how do you test that? 00:14:31.565 --> 00:14:36.835 And that could also, you know, touch on maybe some of the benefits of effects 00:14:36.835 --> 00:14:38.765 systems and how that impacts testing. 00:14:39.230 --> 00:14:42.680 Um, but also focus on, okay, if you're doing IO, how do you 00:14:42.680 --> 00:14:44.000 actually test that effectively? 00:14:44.690 --> 00:14:48.770 Um, and that's just scratching the surface of the topics that could be covered here. 00:14:48.770 --> 00:14:51.200 And there's so much, but yeah, I would love to see, 00:14:52.245 --> 00:14:55.185 >> yeah, this could easily turn it into a 500 page book. 00:14:55.570 --> 00:14:55.870 >> yeah. 00:14:56.355 --> 00:15:00.015 >> maybe we should start with a couple hundred page books to get people. 00:15:00.564 --> 00:15:00.834 Yeah. 00:15:01.165 --> 00:15:03.365 A little bit more prepared and geared up for 00:15:03.700 --> 00:15:04.870 >> Like some magazines. 00:15:05.444 --> 00:15:06.555 >> yeah, yeah. 00:15:07.215 --> 00:15:07.395 Yeah. 00:15:07.395 --> 00:15:11.084 I was going to say like, uh, catalogs, you know, like, you know, how like 00:15:11.084 --> 00:15:14.655 series back in the day would just mail you a catalog with all the 00:15:14.655 --> 00:15:18.405 things you could buy, you know, maybe we do that for testing Haskell. 00:15:19.415 --> 00:15:19.925 >> I like it. 00:15:20.324 --> 00:15:20.655 >> Yeah. 00:15:21.105 --> 00:15:26.625 Well, I was mentioning earlier at the other TDD, um, and this is type 00:15:26.625 --> 00:15:28.185 driven development with Haskell, which. 00:15:29.130 --> 00:15:36.390 Is one of the strengths of Haskell is its type system and, uh, really 00:15:36.480 --> 00:15:42.510 kind of understanding and, and yeah, I guess understanding and grokking 00:15:42.510 --> 00:15:47.790 are the same thing, but, uh, really getting a deeper knowledge base of how 00:15:49.230 --> 00:15:51.720 the type system works, how, you know, 00:15:51.720 --> 00:15:56.685 the type there's tight families there's type, uh, Applications 00:15:56.685 --> 00:15:58.785 there's type all kinds of type. 00:15:59.110 --> 00:15:59.890 >> Pretty much type. 00:15:59.980 --> 00:16:01.390 It can be a prefix on anything. 00:16:01.715 --> 00:16:02.495 >> Right, right. 00:16:02.855 --> 00:16:07.355 And so why don't we, why don't we take some time and create 00:16:08.645 --> 00:16:13.565 a verbose book on the type type system and type driven development in a Haskell. 00:16:14.050 --> 00:16:14.350 >> Yeah. 00:16:14.770 --> 00:16:17.020 and not only covering the. 00:16:17.915 --> 00:16:20.495 Different things you can do with the type system. 00:16:20.495 --> 00:16:23.555 Like what is the type family, what does it allow you to do? 00:16:23.615 --> 00:16:25.955 And then also, why might you want to do that? 00:16:25.955 --> 00:16:30.485 So like I touched on earlier with like affect systems and how they affect, pardon 00:16:30.485 --> 00:16:35.795 the pun, how they influenced testing, um, you know, for type different development. 00:16:35.885 --> 00:16:41.555 Like I know about type families, but why might I want to use them? 00:16:41.555 --> 00:16:43.025 What problems do they solve? 00:16:43.055 --> 00:16:46.205 What things you know, which states are then. 00:16:46.550 --> 00:16:51.260 On representable because I've chosen to use type families or J DTS or, you know, 00:16:51.530 --> 00:16:58.250 uh, functional dependencies or any number of the type based, um, language extensions 00:16:58.310 --> 00:17:02.270 in GHC and it could be shenanigans yeah. 00:17:02.420 --> 00:17:04.010 Type based shenanigans. 00:17:04.640 --> 00:17:06.860 Um, he doesn't list. 00:17:06.860 --> 00:17:10.220 So in these kind of, uh, hypothetical books that we've 00:17:10.220 --> 00:17:11.720 been talking about, he lists. 00:17:12.140 --> 00:17:15.920 Some other books from other programming languages that touch on these topics. 00:17:16.430 --> 00:17:22.160 And one that I think could be brought up here is not a printed book, but the 00:17:22.160 --> 00:17:29.270 servant, um, both their like documentation for the servant library and the kind of 00:17:29.270 --> 00:17:34.280 rationale for why they built it and how they built it and how you might build your 00:17:34.280 --> 00:17:36.740 own kind of minimal servant style library. 00:17:37.340 --> 00:17:39.410 Um, because that is some very advanced. 00:17:39.709 --> 00:17:44.989 Type level stuff, and they do a very good job of motivating why you need 00:17:45.049 --> 00:17:48.080 each step along the way, like, oh, wouldn't it be nice if you could write 00:17:48.169 --> 00:17:50.509 something like this, it turns out you can't, unless you turn on this 00:17:50.509 --> 00:17:51.979 extension, what does that extension do? 00:17:51.979 --> 00:17:54.679 It does this and here's how it changes the code. 00:17:55.570 --> 00:17:55.840 >> all right. 00:17:55.840 --> 00:17:59.169 So we're just pawning this book off the serpents in the law library, 00:17:59.169 --> 00:18:01.330 maintainers of that library. 00:18:01.360 --> 00:18:02.110 Okay, cool. 00:18:02.189 --> 00:18:02.860 I'm down. 00:18:02.919 --> 00:18:03.249 Yeah. 00:18:03.549 --> 00:18:08.350 And I like that he makes a good point too, here in his little, kind of a synopsis 00:18:08.350 --> 00:18:12.669 of what this book would be about where, you know, there's a lot of languages that 00:18:13.029 --> 00:18:16.090 have kind of taken bits and pieces of. 00:18:16.800 --> 00:18:19.800 Haskell's type system and implement engine at their own language. 00:18:19.889 --> 00:18:25.620 And so it could be nice to kind of show, Hey, this has been in Haskell all along. 00:18:25.649 --> 00:18:29.429 Here's all the things that Haskell's allows you to do that. 00:18:29.429 --> 00:18:32.970 Yes, you may be able to do now in other languages, but Haskell's been 00:18:32.970 --> 00:18:36.540 doing it longer and they're trying to make it better every step of the way. 00:18:36.929 --> 00:18:41.970 Um, you know, and as we start to come out with newer iterations of the Haskell 00:18:41.970 --> 00:18:45.179 language, um, right, we've got GA she. 00:18:45.540 --> 00:18:49.170 2020, which is a group of language extensions that probably help a 00:18:49.170 --> 00:18:50.880 lot with the type level of stuff. 00:18:50.970 --> 00:18:56.130 Um, and getting more examples of how that affects, you know, the 00:18:56.130 --> 00:19:00.960 day-to-day code, writing of Haskell and what it allows you to do. 00:19:01.440 --> 00:19:03.540 Cause I think we're missing that and you know, sure. 00:19:03.540 --> 00:19:08.340 You can read blog post, or you could read the specs for every language 00:19:08.340 --> 00:19:12.570 extension and how this works, but unless you can see like, uh, end to 00:19:12.570 --> 00:19:16.679 end example, And something that's walking you through and motivating 00:19:16.679 --> 00:19:21.000 you, like, like the servant library does and the documentation around it. 00:19:21.449 --> 00:19:25.590 You know, people aren't going to really dive in and take that direction 00:19:25.590 --> 00:19:30.510 unless you have a desire to know that, which is if you do that's awesome. 00:19:30.510 --> 00:19:32.909 Like explore it, take the time, learn it. 00:19:32.939 --> 00:19:33.510 It's awesome. 00:19:33.510 --> 00:19:34.110 It's great. 00:19:34.110 --> 00:19:36.600 We'd ha have you servant here? 00:19:37.740 --> 00:19:38.399 And we. 00:19:39.074 --> 00:19:42.225 You know, yes, it was a little bit of a headache at first, but now that we have 00:19:42.225 --> 00:19:46.635 that type safety, we are grateful and we've really become accustomed to it. 00:19:46.635 --> 00:19:48.225 And we've kind of forced our hand at 00:19:48.225 --> 00:19:50.895 learning the type system a little bit deeper. 00:19:51.375 --> 00:19:54.105 Um, so if we had books like this would be helpful. 00:19:54.605 --> 00:19:54.865 >> it would. 00:19:54.865 --> 00:19:56.915 And, uh, you know, you mentioned like, 00:19:57.905 --> 00:20:01.024 These, some of these things are already available as blog posts and for the 00:20:01.024 --> 00:20:05.375 people that are interested in pushing the boundaries of the type system, that 00:20:05.495 --> 00:20:08.284 material is already out there, they can go read the papers they came from. 00:20:08.284 --> 00:20:12.695 They can read the GFC documentation, but that motivating example to bring you 00:20:12.695 --> 00:20:15.875 from why should I care about this at all? 00:20:16.115 --> 00:20:17.105 All the way to. 00:20:17.435 --> 00:20:18.425 Man, this is awesome. 00:20:18.425 --> 00:20:20.014 I'm so glad that Haskell does it. 00:20:20.375 --> 00:20:25.504 We don't have a resource or even a path of resources that can do that for somebody 00:20:25.504 --> 00:20:27.395 that isn't already steeped in this stuff. 00:20:29.555 --> 00:20:33.095 Um, so at this point we've talked about test driven development 00:20:33.455 --> 00:20:34.655 type driven development. 00:20:34.895 --> 00:20:39.125 I think there's a third one in this list of domain driven design. 00:20:39.215 --> 00:20:42.725 So we got TDD, TDD and DDD. 00:20:43.475 --> 00:20:44.315 So what's DDD. 00:20:47.929 --> 00:20:56.774 >> um, So domain-driven design is really the concept that your code and 00:20:57.615 --> 00:21:03.344 what you write, describe like the complex domains that you're applying it to. 00:21:03.705 --> 00:21:07.635 Um, so, you know, when you're writing functional programming 00:21:07.945 --> 00:21:11.774 in functional programming, it tends to be easier to do this. 00:21:11.804 --> 00:21:12.645 And so, yeah. 00:21:13.139 --> 00:21:13.429 Yeah. 00:21:13.499 --> 00:21:18.029 People try to use domain driven design in object oriented languages. 00:21:18.529 --> 00:21:22.999 It is possible, but they also have a crap ton of resources for it. 00:21:23.090 --> 00:21:27.019 And there's a lot more examples of things going on out there. 00:21:27.379 --> 00:21:27.919 And so. 00:21:28.710 --> 00:21:32.640 We could show improve to the outside world and those other mainstream 00:21:32.640 --> 00:21:36.030 languages, that high school is the best. 00:21:36.120 --> 00:21:42.060 Is it one of the best languages to be able to use domain driven design? 00:21:42.570 --> 00:21:45.600 Um, I keep wanting to say development, but I know it's not. 00:21:45.600 --> 00:21:53.190 So I somehow keep correcting myself, but you know, those are, you know, because 00:21:53.190 --> 00:21:55.860 there's no real book out there right now. 00:21:55.860 --> 00:21:56.640 Not everybody. 00:21:57.314 --> 00:21:59.385 You know, Nasser's blog posts, and we've talked about 00:21:59.385 --> 00:22:02.735 those a lot, but it'd be nice to have the full picture. 00:22:03.334 --> 00:22:06.274 And I feel like a book on it would help. 00:22:06.844 --> 00:22:10.175 >> Yeah, I would really like to read a book like this. 00:22:10.624 --> 00:22:14.314 I have a passing familiarity with domain-driven design. 00:22:14.465 --> 00:22:17.884 I'm kind of aware of the concept, but I don't think I could explain 00:22:17.884 --> 00:22:23.495 it that well, um, that being said, I feel like Haskell is an exceptionally 00:22:23.495 --> 00:22:27.034 good language for modeling domains. 00:22:27.094 --> 00:22:30.784 So if that's what domain-driven design is about, then I think Haskell excels at it 00:22:30.814 --> 00:22:32.914 and having a book that kind of lays out. 00:22:33.319 --> 00:22:37.939 Why that's the case and how to use Haskell's features to effectively 00:22:37.939 --> 00:22:39.679 model domains would be amazing. 00:22:40.189 --> 00:22:43.969 Um, but to kind of bolster my own point here, one of the reasons why I think 00:22:43.969 --> 00:22:49.129 Haskell is so good at modeling domains is that the combination of product and 00:22:49.129 --> 00:22:53.959 some types along with pattern matching, which other languages have these days 00:22:53.989 --> 00:23:00.395 swift and rest are, are getting that or have that, um, Those relatively 00:23:00.395 --> 00:23:08.814 simple tools, make it so easy to exclude impossible states from your program or 00:23:08.814 --> 00:23:10.314 push them all the way to the boundary. 00:23:10.345 --> 00:23:12.955 So like when you talk to the database, something could go wrong 00:23:12.955 --> 00:23:14.064 and you'll handle the error there. 00:23:14.095 --> 00:23:17.665 But then once it gets into the system, you know that you have a 00:23:17.665 --> 00:23:23.605 bonafide user or, you know, episode or whatever your domain object is. 00:23:23.605 --> 00:23:25.735 You actually have one of those things on hand and you don't have 00:23:25.735 --> 00:23:27.054 to worry about it becoming invalid. 00:23:28.820 --> 00:23:29.300 >> Right. 00:23:29.390 --> 00:23:29.690 Yeah. 00:23:30.350 --> 00:23:31.760 It's provides a lot of safety. 00:23:32.240 --> 00:23:32.600 >> Yeah. 00:23:33.220 --> 00:23:37.810 And that means peace of mind for people like me, who, uh, came from, you know, 00:23:37.810 --> 00:23:41.949 I used to program in Ruby doing a lot of object oriented stuff and you Taishan, 00:23:41.980 --> 00:23:47.350 and it was always, uh, a challenge to know, okay, I have one of these 00:23:47.350 --> 00:23:52.149 things on hand that says it's a user, but it doesn't have this field set. 00:23:52.149 --> 00:23:54.310 And this, you know, other fields is supposed to mean this thing, 00:23:54.310 --> 00:23:55.240 but it means this other thing. 00:23:55.240 --> 00:23:58.144 And it's like, okay, well, What am I supposed to do with this? 00:23:58.204 --> 00:23:58.594 I don't know. 00:23:59.270 --> 00:23:59.570 >> Yup. 00:23:59.600 --> 00:23:59.899 Yup. 00:24:00.110 --> 00:24:01.879 That's the world of JavaScript as well. 00:24:02.480 --> 00:24:02.540 Yeah. 00:24:03.030 --> 00:24:06.090 It makes me cry every night. 00:24:07.290 --> 00:24:07.679 When I 00:24:07.679 --> 00:24:08.879 think about the past. 00:24:10.139 --> 00:24:11.550 Sorry, I'm coming back. 00:24:11.850 --> 00:24:12.510 Let me come back. 00:24:13.080 --> 00:24:14.070 Oh, okay. 00:24:14.245 --> 00:24:14.334 >> it. 00:24:15.024 --> 00:24:15.294 Yeah. 00:24:15.654 --> 00:24:18.414 Uh, so should we move on to the next, uh, hypothetical 00:24:18.414 --> 00:24:18.954 book topic? 00:24:19.409 --> 00:24:19.620 >> Yeah. 00:24:19.620 --> 00:24:20.879 I think, I think this will be the last one. 00:24:20.879 --> 00:24:21.750 We'll probably cover and we're 00:24:22.110 --> 00:24:26.040 getting there on time, but, uh, what's the next one there to 00:24:26.395 --> 00:24:31.254 >> So the next one is one that I'm excited about, which is event sourcing 00:24:31.495 --> 00:24:34.824 CQRS and reliable systems in Haskell. 00:24:35.034 --> 00:24:41.965 And for those that don't know, C, Q, R S stands for a command query responsibility, 00:24:41.965 --> 00:24:48.145 segregation, and effectively, what that means is you segregate or separate. 00:24:48.485 --> 00:24:52.835 Your commands, things that change your system and your queries, things 00:24:52.835 --> 00:24:56.075 that ask the system for information. 00:24:56.615 --> 00:25:01.475 Um, and this is, uh, well and backing up even further in the title two event 00:25:01.475 --> 00:25:06.215 sourcing, what does that, uh, event sourcing is like instead of having 00:25:06.215 --> 00:25:11.735 a database that you update in place, you have a stream of events and as 00:25:11.735 --> 00:25:16.475 new events come in your view of the current state of your database changes. 00:25:16.940 --> 00:25:20.660 But your actual source of truth is that stream of events. 00:25:20.960 --> 00:25:26.450 So a good example of this I think is like instead of a user changing 00:25:26.450 --> 00:25:30.889 their name and you say, okay, update table users, set name, equal new 00:25:30.889 --> 00:25:33.470 name, where ID equals one, two, three. 00:25:34.160 --> 00:25:37.760 Um, that's kind of the traditional way of doing it with event sourcing. 00:25:38.000 --> 00:25:42.590 Uh, you would say we have a new event that came in that says user one, two, 00:25:42.590 --> 00:25:44.240 three, changed their name to new name. 00:25:44.780 --> 00:25:45.320 And that's it. 00:25:45.560 --> 00:25:50.240 And it's up to you to kind of, uh, collapse all of your events down into 00:25:50.240 --> 00:25:54.320 one thing that you can look at and deal with like a normal database. 00:25:56.889 --> 00:26:00.490 So this is kind of an advanced topic, but I think it would be a really 00:26:00.490 --> 00:26:01.840 fun one to explore and Haskell. 00:26:02.590 --> 00:26:02.860 >> Yeah. 00:26:02.860 --> 00:26:05.860 I think it would mean just from your explanation. 00:26:05.860 --> 00:26:08.469 It's something that I haven't really heard of or dealt with. 00:26:08.469 --> 00:26:09.560 So I think. 00:26:09.990 --> 00:26:14.399 Having a book, maybe I'll, um, I may look into some blog post after this 00:26:14.580 --> 00:26:20.250 conversation, but, um, you know, trying to have a book that explains this and 00:26:20.250 --> 00:26:25.800 helps relate it to, you know, really how to implement this in Haskell and how that 00:26:25.800 --> 00:26:27.929 would work, uh, seemed super interesting. 00:26:28.320 --> 00:26:31.199 Um, I know we have some, I know they have like ones for some 00:26:31.320 --> 00:26:33.959 Azure stuff and stuff like that. 00:26:33.959 --> 00:26:36.959 So they have something along those lines, but it's not, 00:26:38.070 --> 00:26:42.915 you know, Exactly what we'd like, like it to be, um, especially for Haskell, which. 00:26:44.530 --> 00:26:47.020 >> to give a couple more kind of footholds into 00:26:47.020 --> 00:26:49.360 this area to explore for you. 00:26:49.360 --> 00:26:54.190 And for other listeners that may be interested event sourcing is also 00:26:54.310 --> 00:26:56.590 often called Kappa architecture. 00:26:56.650 --> 00:26:57.070 I think. 00:26:57.665 --> 00:27:02.255 Um, and that's kind of where the stream of events is your source of truth. 00:27:02.765 --> 00:27:08.795 Um, and in Haskell, there is a library called acid state that actually implements 00:27:08.795 --> 00:27:12.965 things like this behind the scenes where you can kind of interact with it 00:27:12.965 --> 00:27:14.555 like a normal database, if you want to. 00:27:14.645 --> 00:27:16.595 But the way that it works is by storing. 00:27:17.045 --> 00:27:17.735 Events. 00:27:17.795 --> 00:27:20.945 And then checkpointing every so often so that it doesn't have to 00:27:20.945 --> 00:27:22.475 roll up all the events every time. 00:27:23.014 --> 00:27:26.254 And it's kind of a crazy way to think about things. 00:27:26.285 --> 00:27:31.445 Um, but it's actually used in production hacking the official 00:27:31.445 --> 00:27:35.764 package repository for Haskell actually uses acid state as its primary. 00:27:37.460 --> 00:27:40.100 >> you're going to say, ask this date was a song by disturbed, 00:27:40.100 --> 00:27:42.830 you know, cause I've got down with the sickness and the other guy. 00:27:43.260 --> 00:27:43.680 State. 00:27:43.690 --> 00:27:44.010 So, 00:27:44.035 --> 00:27:44.514 >> Yeah, 00:27:44.605 --> 00:27:45.145 it could be. 00:27:45.750 --> 00:27:46.080 >> I don't know. 00:27:46.440 --> 00:27:47.430 Anyways, that's cool. 00:27:47.970 --> 00:27:52.260 I'll have to check out acid state and stay away from actual acid 00:27:52.750 --> 00:27:52.959 >> Yeah. 00:27:52.990 --> 00:27:54.730 Don't take that as an endorsement. 00:27:54.850 --> 00:28:00.459 Um, I'm not a huge fan of acid state, but it is a mind-bending concept. 00:28:00.459 --> 00:28:01.720 So check it out for that reason. 00:28:03.260 --> 00:28:06.710 >> so if you want to have your mind bend, go to ass state. 00:28:07.100 --> 00:28:07.370 Hmm. 00:28:07.490 --> 00:28:08.600 Now I see why it's named that. 00:28:08.980 --> 00:28:09.580 >> Exactly. 00:28:09.750 --> 00:28:10.080 >> right. 00:28:10.620 --> 00:28:10.830 There. 00:28:10.830 --> 00:28:11.370 It is. 00:28:11.970 --> 00:28:12.450 Awesome. 00:28:12.450 --> 00:28:17.040 Well, uh, yeah, I think that does it, I mean, this is a great post by Alexander. 00:28:17.670 --> 00:28:18.330 Go check it out. 00:28:18.330 --> 00:28:21.030 There's going to be a link in the show notes. 00:28:21.030 --> 00:28:22.740 So check that out. 00:28:22.830 --> 00:28:27.750 Uh, and you know, if you find any interest in any of these or have experience with 00:28:27.750 --> 00:28:29.940 these, you'll start writing a book. 00:28:30.660 --> 00:28:31.290 Well, thank you. 00:28:31.620 --> 00:28:32.430 Just go on. 00:28:32.430 --> 00:28:35.370 Leanpub charge 50 bucks for it. 00:28:35.550 --> 00:28:35.670 You 00:28:35.670 --> 00:28:37.620 know, you'll make 40 bucks a pop. 00:28:37.680 --> 00:28:38.250 It'll be good. 00:28:38.945 --> 00:28:39.574 >> Yeah, I was going to 00:28:39.574 --> 00:28:43.385 say, it seems like Haskell books have a pretty good track record 00:28:43.415 --> 00:28:44.284 on Leanpub. 00:28:44.705 --> 00:28:49.985 So we've talked on this show with Marco, Sam Pellegrini, author of the simple Ascal 00:28:49.985 --> 00:28:55.445 handbook, which was recently number one on Leanpub and also, uh, Matt Parsons. 00:28:55.955 --> 00:28:58.385 Uh, and his book I think was at number one as well. 00:28:58.385 --> 00:29:01.594 So it seems like a good way to distribute Haskell books. 00:29:03.585 --> 00:29:05.655 >> go Haskell, go lean pub. 00:29:06.585 --> 00:29:08.835 I think the Haskell foundation may partner with lean 00:29:08.835 --> 00:29:12.225 pub to help create more content. 00:29:12.790 --> 00:29:14.590 >> Yeah, that sounds like a good idea to me. 00:29:14.955 --> 00:29:15.254 >> Yeah. 00:29:15.909 --> 00:29:16.090 >> All right. 00:29:16.090 --> 00:29:16.360 Gamble. 00:29:16.360 --> 00:29:17.229 You got anything else? 00:29:17.895 --> 00:29:19.275 >> Uh, I think That's about it for me. 00:29:20.179 --> 00:29:21.229 >> That's all I got to. 00:29:22.009 --> 00:29:25.879 Well, listeners, thank you so much for listening to the Haskell weekly podcast. 00:29:26.029 --> 00:29:28.050 I've been your host Taylor Fausak. 00:29:28.159 --> 00:29:30.679 And with me today, as usual was Cameron Gera. 00:29:31.340 --> 00:29:34.850 If you'd like to find out more about us, you can visit our website, 00:29:34.939 --> 00:29:37.019 which is HaskellWeekly.News. 00:29:37.825 --> 00:29:37.945 >> Yeah. 00:29:38.115 --> 00:29:42.225 Yeah, I know you say as usual, but I feel like it's been like every other 00:29:42.225 --> 00:29:46.125 time nowadays, cause you've been doing all these cool interviews, but anyways, 00:29:46.125 --> 00:29:51.254 Haskell weekly is brought to you by it pro TV, the e-learning platform for it 00:29:51.254 --> 00:29:53.565 professionals and also our employer. 00:29:53.775 --> 00:29:56.985 They would love to extend an offer of 30% off the lifetime of your 00:29:56.985 --> 00:30:03.585 subscription using the promo code Haskell weekly 30 at checkout, all one word. 00:30:04.245 --> 00:30:05.145 I'm pretty sure. 00:30:05.145 --> 00:30:07.545 All lowercase, if not, 00:30:07.570 --> 00:30:07.870 >> do. 00:30:09.375 --> 00:30:12.225 >> did we ever fix that bug anyways?