083: Learn Haskell, Think Less

Hosted byCharles Lowell and Elrick Ryan

September 25th, 2017.

Julie Moronuki: @argumatronic | argumatronic.com

Show Notes:

  • 00:57 - Julie’s Unique Origin Story Into Programming
  • 03:47 - Good Resources vs Bad Resources for Learning Haskell
  • 11:18 - Areas to Look at Before Taking on Haskell and Functional Programming
  • 15:56 - Terminology
  • 17:50 - The Haskell Pyramid
  • 25:51 - Learning Haskell Vocabulary
  • 28:20 - Monoid and Functor
  • 42:06 - Advice for Someone Who May Not Be Interested in Programming



CHARLES: Hello everybody and welcome to The Frontside Podcast, Episode 83. My name is Charles Lowell, a developer here at the Frontside and your podcast host-in-training. With me today on the podcast is Elrick also. Hello Elrick.

ELRICK: Hello. How you doing?

CHARLES: I'm doing well. I'm glad to have you on this one. I'm glad to be doing this podcast in general. We have someone on the podcast today who I've been following for, I guess probably about two years because she published a book that has been very, very helpful to me. It's one that I recommend to a lot of people. It is learning Haskell from first principles. With us on the show is Julie Moronuki, who is co-author of that book. Thank you so much, Julie for coming.

JULIE: Yes, hi! Happy to be here. It's nice to finally get to talk to you.

CHARLES: Yeah. One of the reasons I wanted to have you on the podcast was because I feel as though you have one of the most unique origin stories because of programming and entering in the tech world. Most of us are curious, we either come from video games or maybe we just start fiddling with the web browser. You enter the maze from the entrance that is like hidden from all, I would say. You went straight to writing a book on Haskell, is that --?

JULIE: That is what happened. In 2014 on Twitter, I met my co-author, Chris Allen and he has been trying to figure out better ways to teach people Haskell because the on-ramping, I guess of people to Haskell can be quite difficult. The materials that exist are not always accessible and people felt like they need the advanced math degrees before they can write Haskell.

He was trying to figure out better ways to introduce people to it. Since I was this person who's never programmed before -- I have no background -- and then he thought, "This will be a very different experience, trying to teach Haskell to her." Because I have a linguistics background and stuff he thought, "That would be interesting too and maybe, she'd be interested eventually in doing NLP." I said, I'm not --

CHARLES: What's that? Acronym alert.

JULIE: Oh, yeah. Sorry. Natural Language Processing. I said, "You know, I've never done any programming and I don't play video games and I never have had any desire to learn computer programming. I don't think I'm going to like this. I don't think this is going to last but sure, I will try," and so I did a little bit. I read a little bit of 'Learn You a Haskell for Great Good.' I've read some other things.

CHARLES: This was before you guys had the idea of actually writing a book.

JULIE: Yes. He had the idea of turning some of his thoughts about teaching Haskell into a book and as he would explain things to me, like the questions I had about 'Learn You a Haskell,' I'd be like, "We should write this down," and he would say, "It's so hard to write it though. It's easy when I'm explaining it to you and it's so hard to write it." Initially, it started that I was helping him at things that he was teaching me and then as we got further into the book and I started reading a lot of other Haskell stuff on my own and figuring stuff out, I was writing more and more of it. Then we were kind of equal co-authors after not too long. That's how it happened. I really didn't think that I would stick with Haskell or with programming. I'm still sometimes I'm not sure about programming. I'm not sure about this whole making software thing. But Haskell is so interesting to me that I'm still here.

CHARLES: That is fantastic and it's a great story. I'm curious, when you were doing the proto-research to learning Haskell, coming from really truly first principles and having no experience of programming, what made a good resource versus a bad resource? What are the things that you gravitated towards and say, "This is really instructive." What was the tone there?

JULIE: One of the major problems ahead of most of the Haskell resources that exist is they assume that you've done programming before because nobody learns Haskell as a first language so they all assume that you have done some programming before. They would make references to things that if you were a programmer, you would know what they meant but I didn't. That was one of the hardest things for me. Even 'Learn You a Haskell' does that to some extent.

CHARLES: What's an example of that?

JULIE: I had learned a little bit about recursion from linguistics because that's a thing in human language so I really understood recursion but most of the Haskell resources explain it to you primarily in terms of, "This will be like your loops in other languages." I'm going to be like, "I don't know what a loop is. This isn't helpful for me." There are a lot of things that I didn't understand so when people talk about Haskell as being a pure functional language, neither pure nor functional necessarily, I didn't have anything to contrast them with so they didn't necessarily make sense to me as things that make Haskell different from other languages.

I didn't know what imperative programming was and people would say, "In contrast to imperative programming, functional programming does this," and I'd be like, "Okay, but I don't understand what the imperative programming way is so this contrast isn't making any sense to me and same thing with purity." There were a lot of things I had to learn, in fact about mutable state because I didn't know anything about it. I had some understanding of how computer memory works but still some of the ways that people talk about it were not obvious to me.

CHARLES: Do you find that seeking out that contrast actually wasn't helpful? Is it noise since at least at the beginning, it's something you'll never do. It's like saying, "Over in France, they wear these kind of socks." Since I'm going out into the street in front of my house, I don't really care.

JULIE: Right. In the beginning, it was a lot of noise and I understand why they do that because they are making the assumption that everybody who is learning Haskell has come from some other programming language, probably an imperative one so I understand why that happens but in the beginning, it was very much noise for me. I noticed a lot of Haskell resources, one of the first things they tell you is that in Haskell you can't do 'x = x + 1'. I was like, "If I'm reading this like it's mathematics, why would I think I could do that." If you come from a different programming language, you might well think that you can do that but in Haskell, we can't so making that contrast, when I didn't have that background was really just confusing for me.

Now, because I teach people and most of them do have some background in an imperative language, understanding the contrast is more helpful to me but in the beginning it was just confusing and noise. When we wrote Haskell book, we tried not to make those kinds of references and like, "Let's assume that everybody is just like Julie, doesn't know a different programming language that we can contrast it with and let's try to write a book like that."

CHARLES: Right. I think that's a key insight because some people would say there's a lot missing or that difference might stand out. Now, that you pointed out, I can see it but I don't think I noticed it while I was reading it. But one of the things that I like is because I also tried to learn Haskell through 'Learn You a Haskell,' and I didn't find it very helpful. I found it entertaining and it's not a knock against the authors. Some of the sketches were really cute but it was still more explaining... I don't know. It was explaining more of the how, than the why, if that makes any sense where I felt as though in your book, there were a lot more analogies to actual human experiences, using the visceral language saying, "A mono is something you can mash together or squeezed together." That really connected for me. Whereas, explaining it in terms of concatenation and laws and stuff like that. Those things seem cited to the secondary resources to the primary resource.

JULIE: Yeah. I think that's kind of helpful for me too. There are different Haskell books that have, I think different things about them that are good. I forget the name of the book but Graham Hutton's book, the way he talks about recursion was really helpful to me. The way he explains recursion and of course, folds but folds are things that he's known for so those parts of that book are helpful for me. But really the best book other than my own of course, for me is Simon Thompson's. I think it's called ‘The Craft of Functional Programming’ and I think it does better at explaining things just in terms of Haskell. Real World Haskell, I guess is really good. It was harder for me because I hadn't been a programmer before. I think it's got so many practical exercises that --

CHARLES: Was that the O'Reilly book by Irish gentleman whose name eludes me?

JULIE: Yes, Brian O'Sullivan. It makes more sense to me now but there were things in it that are sort of programmer things. Because I'd never made software before, that were really confusing for me. But Simon Thompson's, because his book does have exercises and they were ones that I could understand and do. They were fairly self-contained. My first experience actually in writing a program that does IO was from his book and I was just so thrilled. I was like, "I got it. I did it." That was really helpful book for me but I don't see people recommend that one as often but that was probably the best one for me.

CHARLES: Yeah, it's always a balance because the Real World Haskell didn't really worked for me, almost because the examples were too pragmatic or too complex and I picked this up when I was 10 years into my programming career and I struggled to follow the JSON parser example, which is parsing JSON is something that I've actually done several times in multiple languages and I still struggled with it.

JULIE: Whereas for me, I don't even know what JSON is. This is not something I've ever dealt with. I know what it is now sort of, but it's still not something that I deal with very much. I was just like, "What is this? I don't even know what to do here." It wasn't quite as helpful for me. I've heard a lot of people have success with that one but I think they don't share quite the same richness of programming experience with Brian O'Sullivan. I think it's a little bit more difficult.

ELRICK: These are a lot of amazing resources that I wish I knew about when I try to learn Haskell. I took an online course with, I think it's like Eric Meijer and that class was very intense. Looking back, what would you say are some areas that someone should, either start to look into before they step into the Haskell world, being that you didn't come from a programming background but connecting to dots backwards now? What would you say are some areas that people can slowly ramp up into to get into Haskell and functional programming?

JULIE: When I teach people Haskell, the people who have the easiest time are people who have been writing Scala for a while and they've moved over to the FP in Scala side. When I first started Haskell, I heard a lot of people make jokes about how Scala is a gateway drug to Haskell. I think there's actually might be so truth in that because I certainly have a lot of students that were Java programmers, then they got interested in Scala because maybe Scala is better for some things than Java and then they start moving more and more over to the FP in Scala side. Those are probably the students that have, I think the easiest time making the transition to Haskell that I've had anyway.

But you know, I think even JavaScript, trying to write in a more functional style and there are some resources for that and really, there's a very good tutorial about monads that uses all the code examples in JavaScript. I think a lot of the concepts that you can start to approach them from other languages. Haskell is still going to be weird in a lot of ways and another thing that works for a lot of people is going to Elm. Elm is similar to Haskell but different. I think that that has worked also for a lot of people getting them into understanding more functional programming concepts but with the much easier... The word easy is so --

ELRICK: It's like a relative term like, "Oh, this is easy."

JULIE: It is.

CHARLES: Easy to say, right.

ELRICK: That's what I thought when I step into learning Haskell and functional programming. I was like, "How bad could it be?"

JULIE: Right. Learning Haskell can be very bad. I'm not going to kid around about that. It's a shame because I don't think that it needs to be that bad but the way it's presented oftentimes, for various reasons, I think why Haskell gets presented the way it does but I don't think it needs to have it like that. The designer of Elm, whose name I'm not going to try to pronounce because I don't know how you say his last name, he really made an effort to for example, the error messages in Haskell can be very intimidating. The situation there has improved since I started learning Haskell but they can be quite intimidating and he really made an effort to make very friendly error messages, very helpful error messages.

I think that it shows and then it makes a difference for people who are learning. If you start with Elm and then you do want to see what Haskell or PureScript, which is also frontend language, mostly. It compose of JavaScript but it's very Haskell-like, then from Elm, let's see if we can get a little more hardcore Haskell. I think the transition to Haskell or PureScript is easier from there.

I think it does help to move in the functional direction from whatever language you're in, if you do FP in Scala or try moving to more functional JavaScript or even Elm. Then Haskell will make it more sense from there or be a little easier to approach.

CHARLES: Yeah, and I definitely think that for, at least from my perspective, I've been able to take a lot of those concepts that I've learned from Haskell and then apply them, even inside Vanilla JavaScript. There are things that have become indispensable like mapping and folding and they exist in JavaScript. You can reduce arrays, which is a similar to a fold and then you can map arrays but understanding that map, the key insight for me that I got from learning Haskell is that there's a whole class of values that you can map, not just arrays.

The standard JavaScript object is essentially a Functor and will get a little bit to that because for people listening what that word even means and the meta around the fact that they're all these weird words and how do I go about something I want to ask you about. But the trees can be mapped and the objects can be mapped and all of the sudden, it's like this one concept that I use so much for lists, it's available on all these different data structures and it's get me thinking like, "What other data structures can I use this operation? What are the things are Functors that I'm working with?" Really, it's changed my perspective to think about the type of the data structure, in terms of the operations.

JULIE: I'm in favor of keeping the terminology that we have but just explaining it much better. That's the approach that I take but it can be very hard, especially it was your first learning Haskell. I don't know if you've seen the Haskell pyramid but to get sort of productive where you can write programs in Haskell is not a very high bar. It feels like it is when you first start but it's not really very high bar but Haskell just keeps growing and growing and getting deeper and deeper so you're always approaching new libraries that you've never seen before and you feel then you've been learning Haskell all over again because they're written in a very different style of Haskell or they have even more terminology, even more kinds of Functors that you've never heard of before or something like that so you're always approaching these things over again.

It can be a very intimidating feeling and it makes a lot of people very uncomfortable and I'd say, if you like Haskell and that does make you feel uncomfortable, then you don't actually need to do that because a lot of people write Haskell very happily every day in their jobs even and don't do that. They don't mess with some of the newer, super cool libraries that have all this funky terminology and stuff. Some of them don't mess with them at all.

CHARLES: But certainly, there is some concepts that are core. I'm thinking of like applicative and Functor and all these things that I'm learning about and I'm curious to hear about your experience as you climb that pyramid. What is the pyramid entailed? First of all, I'd love to hear more about it because this is actually the first time I heard about the Haskell pyramid.

JULIE: Say you understand monads, then you can write really a lot of Haskell programs. Probably at some point, you will need to understand monads transformers but if you just get to the point where you understand monads pretty decently, you can write a lot of software so after that, then learning more is maybe going to improve your Haskell, maybe let you write some things that you couldn't write before but a lot of it above, not that these things are necessarily in an hierarchical progression. We cover monad transformers in a fair bit of detail in Haskell book but if you get anything beyond what's in Haskell book, one of those things that some of them are very interesting, some of them can make you much more productive but some of them are also people do them for fun to explore the space and some people love them and some people hate them. Haskell lets you do a lot of things for fun and exploring mathematics in ways that are interesting and exciting and may influence and in fact, have influenced other languages like [inaudible] in PureScript but not really necessary for basic Haskell programming.

A nice thing happened while we're writing Haskell book. I was writing, I think it's chapter six, which is about type classes. I was writing that chapter and at the same time, my co-author had started writing the Monoid chapter. The type classes chapter comes in chapter six and we introduce a lot of the basic type classes: num and eq and some of those in that chapter because I do think it's important. Type classes are very special thing about Haskell so I think it's important to, at least start coming to groups at them early. Some people disagree with me about that and think they can ignore them for much longer. But at any rate, it is where it is and I felt that that was important.

Maybe the real motivation for type classes, really until we started writing the Monoid chapter so he started writing that while I was working on type classes chapter and he sent me the beginnings of the Monoid chapter to look at. At first I thought, "We've got addition and multiplication and list concatenation and this just doesn't seem interesting. What is this generalization of a Monoid that I'm supposed to get from these three things? And why bother making it a type class," because additional and multiplication are already in the num type class and then list concatenation is just for list so why make this into a type class and what's that motivation there. With eq, we want a quality --

CHARLES: Is that how you pronounce 'eq?'

JULIE: That's how I pronounce it because 'equal' or equality.

CHARLES: Okay, so this is a type class for doing what? Making sure to being able to compare two values on the same value.

JULIE: Yes and it's a weird one because for most data types, you can have an eq instance and you want probably, in a lot of cases to have that but we don't want because function is a data type in Haskell so you don't want to have an eq instance for functions and that's why equality is not implemented generally for everything. That's why it's a type class so there's no instance for functions because that's not decidable. You can't decide if two functions are equal, generally. Some functions you can but in the general terms, for datatype, you can't.

CHARLES: That's actually a pretty profound statement. Proof of which is left as an exercise for the listener.

JULIE: We got to the Monoid and I was like, "What is the [inaudible]," or something. It turns out that there are Monoids everywhere. There's all kinds of things that you want to, either concatenate or make a product of. Then having this as a type class and thinking of it in terms of like, "We've got this abstraction. We've got this category. We've got this algebraic structure. Now, we can look for in all these other places," because once you've named the thing, then you can talk about it and think about it in a little bit of the different way. It's like, "Now, we've got this group of addition, multiplication, list concatenation." Now, we've got an abstraction of that and we can think, "Where else can I see this pattern?" and it turns out it's all over the place.

For me, that was one of our thought like, "Type classes are actually really cool and powerful and interesting thing." For me, that was when it seemed like, "The terminology is worth it because, now I want to think about finding these algebraic structures and in all these other places."

CHARLES: Right and like a Monoid, it could essentially be called, if you're using a Java interface, like 'mashable togetherable' or 'concatenatable' or something like that. But there's a kind of one-to-one correspondence but it is a vocabulary that just needs to be learned.

JULIE: I don't know much about category theory or anything but the other cool thing about Monoid for me was that there are almost always two because there's almost always one that's destructive or additive or concatenative and there's almost always one that is conjunctive or a product or multiplicative. It's often across product that would be the zipless Monoid that exist in base and it's a cross product of the two lists.

There’s almost always two, whereas when you think of Monoids in the very abstract looking category theory, it doesn't matter if it's addition or multiplication. The operation doesn't matter, whether it's addition or multiplication or concatenation or cross product because you generalize the actual operation to the extent where what it's going to produce. It doesn't matter anymore. For me, I still think of Monoids in terms of like set theory or Boolean Algebra, then that's one of the things that I think is difficult with Haskell where people talk about Monoids in terms of category theory but I think that's not very helpful for the actual programmer who has to actually deal with the two different instances like sum and products or concatenation and zipping are going to actually act different in a program.

CHARLES: Right, they're going to yield a different set of values.


CHARLES: Is there a baseline vocabulary? I kind of think of it like learning a new language, right?


CHARLES: When you're learning Haskell, you're not just learning a new language. You're literally learning a new language. I could go and I could learn Japanese but it's going to be a struggle at some point. People say certain languages are hard and certain language are easy. I don't generally subscribe to that. I think that most of it is just going about and living in a place where they speak this language and you'll absorb it and it's the decision to go and live there -- that's kind of the primary one.

But let's say, you're a foreigner and you're travelling to this country called Haskell that's got this strange language. Like other human languages, it's just got different names associated with different concepts and some of the concepts might even just be unique to that country. Just like when you're travelling and acquiring a human language, there's a certain level of vocabulary that you need to achieve before you can do things like buy groceries and be able to transact financial exchanges or have a conversation about the weather. What are the kind of the levels of vocabulary that you need to acquire to be operational in Haskell or I would say, even in functional programming because now that I've been exposed to this, I see it in Clojure. I actually see people doing this JavaScript and in Erlang, in Elixir and what have you.

JULIE: Yeah, I don't really know how to answer this question. How to buy groceries in Haskell?

CHARLES: Let me let scale that down because I had this horrible tendency to spend five minutes asking what I say is going to be single question but it's actually like 30. Let's take down the scope. When you were learning this vocabulary, at what point did you feel like you're really gaining traction? We're you really starting to connect the dots?

JULIE: For me, I think when I got through Functor. It was when I felt like --

CHARLES: Functor and what comes before Functor?

JULIE: Monoid. I think once you understand Monoid and Functor, then a lot of other concepts in Haskell will start falling into place because this is not obvious to everyone but I think once you really understand Monoid and once you really understand Functor, then applicatives are monoidal Functors and that's not obvious to everyone. Like I said, it's not obvious at first certainly, and monads have characteristics of both Monoid and Functor as well. Then you start saying, "There's all these other Functors. There's profunctors and bifunctors. I think once you really understand Monoid and Functor, a lot of the rest of Haskell starts falling into place and then type classes like alternative. Alternative is another kind of Monoid.

We have all these other names that if you can see the general pattern of Monoids and Functors, I think to me anyway, a lot of it then just started falling into place. Applicatives to me seemed, I don't want to say obvious or simple but in traverse, it's same sort of thing so we have these other names for it -- traversable -- and I was like, "Why was it called traverse. I don't understand this word at all." But once I saw the type signature and what actually happens with what the function traverse does, I was like, "Okay, I see what's happening here." For me, those were the two big hills. Once I got through Monoid and Functor and really understood them well, then a lot of other stuff just come and fell into place for me.

ELRICK: This is really interesting. How was a Monoid explained to you when you were first starting to learn Haskell? Then now, how do you explain what a Monoid is to someone that's learning Haskell?

JULIE: When Monoid was first explained to me, it was the pattern of there's addition and multiplication and list concatenation so it generalize out that pattern and that was really hard for me to understand at first because list concatenation and addition are similar but multiplication is different. I was like, "What do these three things have in common?" What they have in common is that they take two values of a certain type and return another value of that type and that's the type signature of the main function, that's in the Monoid type class. But that doesn't really tell you very much. A lot of functions could do that, in theory at least. How you combine them is really what's interesting about Monoid and also what makes concatenation and addition different from multiplication.

Fortunately in college, I had had a fair bit of exposure to Boolean Algebra so figuring out that like, "There's actually two basic genres or varieties of Monoid and they are disjunctive or additive or they are conjunctive or multiplicative," and figuring that out, to me I always think that Monoid should really be, maybe two different type classes, one for the additive Monoid like list concatenation and addition and things where you are adding two things like a set union.

Then conjunctive, which would be this intersections or multiplication or cross products. I always think there's maybe should be two different type classes but there's not a good way to do that really in Haskell. Instead, we have this one type class and then we do this ugly business of wrapping them in different type names.

CHARLES: Is that why you'll have a constructor for some so it's just a wrapper for an integer?

JULIE: Yeah.

CHARLES: I don't know if that's so bad.

JULIE: I don't like it but --

CHARLES: Yeah. You know what? You do a lot more than I do so I'm going to take your word for it.

JULIE: Yeah, that's exactly why. Sum and product are the wrappers for integers because integer doesn't have a Monoid. It has two Monoids over it.

CHARLES: I see. There's lots of ways to combine integers.

JULIE: Yeah and those are the two basic ones. Then because Monoids also have an identity so with semi-groups, then you get even more semi-groups for integers because you get max and min, because they don't have an identity so there's semi-groups.

CHARLES: There's always risk getting down into the weeds with the vocabulary but I think that there's a message here because your answer to the question is really, "When I understood Monoid and I understood Functor," from that point on, the overhead that you had to expend to get other things was lower than the overhead that you had to expend to get those initial two things. For anyone listening, Monoid and Functor are probably opaque terms. You have no idea what the hell they mean. We've been talking about in things like that a little bit but then it's okay because they're a finite set of opaque terms and they're very achievable and once you can achieve those, then you've done 90% of the work and now, you're just combining them into interesting and novel ways.

JULIE: Yes. I will say it that a lot of people do tell us about Haskell book that applicative is actually the hardest chapter in the book, not monad but applicative.

CHARLES: Really?

JULIE: Yeah. A lot of people do tell us that. Because that's the first time that you've taken the concept of Monoid and the concept of Functor and combining them into a new thing so then, once you've done that with applicative, then after that, really it's all downhill.

CHARLES: Right. It seems like there's a couple of key insights. As you're climbing that hill, I like that analogy is like one, just understanding that there things like type classes so you've through attacking Monoid and through attacking Functor, you realize, "There is such a thing." By recognizing there is such a thing as a Functor, you recognize that there is the potential for other type classes like it. Then through combining it with Monoid, to get applicative, you can see, "I can actually compose these things into new instances of those things," and then that's either the crest of the hill or the Pandora's box, depending on which way you look at it. I think there's a hopeful message in there that if you can invest the time to learn these opaque terms and making them transparent to you, you can really, really, really lean heavily on that knowledge in going forward.

JULIE: Yeah. I'm writing a new book now called 'The Joy of Haskell.' The idea of The Joy of Haskell is meant to be an intermediate book. For people who already know some Haskell but we want to make words like Functor more general, like in Haskell book we really focused on the type class called Functor when it's actually a concept from mathematics or actually originally from linguistics oddly enough but we really focused on the type class in there, rather than trying to explain what a Functors are generally.

In the new book, in The Joy of Haskell, we're going to try to take a lot of these terms like Monoids and Functors and catamorphisms and all these other words that Haskell has used all the time and try to explain them generally. Then also give examples like interesting uses from different libraries and stuff like that. It'll service both, hopefully a guide to the vocabulary of the Haskell ecosystem and also some documentation and examples for libraries and things like that that are useful because these things do have uses. They do get used in interesting and exciting or terrifying -- maybe those are related -- ways. That's the goal of the new book is to try to make a guide to all of this vocabulary that Haskell use all the time. We're trying to do that.

How do I explain Monoids, you asked. You've got two values of whatever type. It doesn't matter the type and in general, there would be two ways you can think of to combine them, either making a sum or a union of all the values in them or making some product of those values, if they contain multiple values or even if they only contain one. That's how I explain them now. I'm not certain that addition and multiplication are actually the best ways to start with that because addition and multiplication don't act quite like set union and intersection do. I'm actually thinking of them in terms of and this is how I explain monoids to the people now, I start from set theory and that sounds really heavy but it doesn't have to be because I think a lot of things about sets are --

CHARLES: They're very intuitive, especially if you have visuals.

JULIE: They're very intuitive, for people to think about. Yes, exactly. I explain Monoid now more in terms of set union and intersection. I'm actually giving a talk in October. It's coming up in just a couple weeks at Haskell eXchange in October 12th and 13th in London and I'm giving a talk there called 'A Monoid For All Seasons' and I'm going to try to explain the theoretic motivation for Monoids and try to explain them in those terms. Semi-group is a little bit different because lacks the identity but I'll try to explain the alternative type class and monad plus this really the same thing as alternative. These things are also just Monoids so we have these different names because it's a different type class alternative but it's really just another kind of Monoid. I'm giving that talk about set theory in Monoids in October, in a couple of weeks. People keep asking me on Twitter, "What's your obsession with Monoids," because my name on Twitter is Monoid Mary so I try to explain why I love them so much.

CHARLES: Actually, it's an awesome point, which I've just gotten to experience it is what you see like, "Oh, there are these abstract things," you start searching for them. A lot of times, you'll uncover them and it'd be a real timesaver. There's the thrill of unearthing it in the first place and then when you could say, "Now that I've identified this thing as a Monoid, there's so much less that I have to write." There's like less work that I have to do. It's the same reason that we write frameworks for ourselves in software. It's like, "We love Ruby on Rails because of all the work we don't have to do." Now, you have to expend a lot of energy to work with it, using Rails an example but there's lots of software frameworks.

It's like, "If you can find a good persistence framework or you can find a good thing for making a library for handling HTTP requests and responses, why would you write it all by hand in the first place?" I think the thing that's exciting for me as a developer is being able to see, "Monoid is a thing. Functor is a thing and I can now actually use this and I can use it almost as a looking glass to explore the world around me. When I see something in the landscape that just leaps out through that lens is another great one." I've been on a big kick lately but being able to say, "This is going to save me so much time because of the thoughts that I don't have to think and the code that I don't have to write." I think connecting it back to the pragmatic, I certainly have become really obsessed, maybe not about Monoids but having a type class large in your mind.

JULIE: I think it's a really powerful thing. Sometimes that jargon is really useful. It's useful in a sense that it like compresses a bunch of information into a single word to remember. It's like teaching my eight-year old multiplication and we were talking about like, "It's like addition," and for us adult, I'll just go ahead say, "It's associative and commutative," but showing him that you can do those things and that addition is like that too and we're talking about that and he was so excited to learn that there's this word 'commutative' that encapsulates this idea for both concepts so he doesn't have to think like, "Addition does this thing. Multiplication does this thing." He doesn't have to remember both of those things, like he just remembers, "Commutative and they're both like this." It kind of compresses that information and what you have to remember and think about.

Then it does make it easier to see that pattern in other things, then we can find commutativity in other things because now we have this pattern that we can look for and we got a name for it. We can talk about it and really, there's a lot of stuff like that in Haskell where we find some pattern that we find useful or we want to be able to talk about or easily translate to a bunch of different types, not translate is quite the right word but you know what I mean, I think. Then we give it a name and we make type class for it and then it's, "Now, we find it even more place for us."

CHARLES: Right. It's about thinking less, right?

JULIE: Yeah.

CHARLES: That's a big misconception is that it's not about thinking more, it's about thinking less.

JULIE: It really is. I think it's because there's so much kind of upfront work, where you have to learn all this new stuff upfront, then people mistake that for how much work we're always doing but in Haskell it's like, "We did all this work upfront and now we're now we're not going to think about these things anymore."

ELRICK: That sounds like a good title for a book, 'Learn Haskell and you will think less," but it's true. When I struggled through that online class, I came out of that just being able to pick up any functional programming language and just hit the ground running. It is definitely a plus and you will think less.

JULIE: Yeah, in the long term, I think that you do. Haskell is not a perfect language. There are things that probably can be improved.

CHARLES: Now, before we go, I wanted to ask you, having had this very unique on-ramp into programming, which apparently you're still not convinced about. I'm curious what it would take to actually convince you but the real question that I have is there any advice that you have for someone who does not have a stereotypical background in programming who may not think that they would find programming interesting, who might have any number of roadblocks in terms of their own conceptions about the path forward. What advice would you have for them?

JULIE: I am a bit joking when I say that I'm still not sure about writing software. I don't feel like I'm good at it and I think this is really the key. There are a bunch of domains in programming that I don't personally care about. I don't want to make web apps and I have nothing but respect and admiration for people who do. To me, it's very, very hard.

CHARLES: Mostly because our tools aren't the same.

JULIE: Yeah and there's just so many things outside your own program, there are just so many things that you have to think about and deal with because there's the network and there's other people's computers and they might be doing in other people software and what it might be doing. It is insane so for me it's very hard. There's a lot of domains of programming that I don't care about and when I thought about programming, that's the kind of thing I would think about. I certainly knew a lot of people who are web developers or the common programming jobs, I guess. Some of them just weren't that appealing to me and I'm not interested in making games or graphics so those are the kinds of things that I thought about for programming.

There are things though that I am interested in doing. I'm very interested in natural language processing and I guess that's related to machine learning. I've recently taken up an interest in things like the raft protocol, the consensus protocol. Those kinds of things interest me a lot and there's a lot of the theory that interests me. I'm reading a dissertation right now about implementing a non-strict lambda calculus, which is what Haskell is. It's a non-strict lambda calculus and this guy's dissertations are theoretically implementing a non-strict lambda calculus.

To me, the theoretical side is really interesting but then I am also interested in certain kinds of software. For some reason, I have developed quite an interest in making Twitter bots. I think that the advice I would give -- I'm rambling a little bit -- to people who think they're not interested in programming so why should they learn or whatever, is just find the thing that you are interested in and there's probably a way you can make software for that and maybe that will be the thing that will get you interested. It might not be Haskell, maybe you are interested in making web apps, in which case I would say go for Elm or PureScript, obviously because I like functional programs but Haskell might not be the best first language for you in that case but find the thing that you're interested in and there probably is a way to write software to do that. There's probably something in programming that will interest you. It's such a vast field.

CHARLES: All right. I really, really like that answer.

ELRICK: Yeah, that's a beautiful advice. Find your domain.

CHARLES: Yeah, it's bigger than you think.

JULIE: It's much bigger than you think.

CHARLES: And there is a place for you. Thank you so much for coming on the show, Julie. I really, really, really enjoyed our conversation.

JULIE: Yes, so did I. This is a lot of fun.

CHARLES: Thank you. Now, before we go, I understand that you are going to be in London, was it roughly very, very soon, you said you were giving a talk.

JULIE: Yes, the 12th and 13th of October. It will be recorded for people who can't get in. It will be recorded, I believe.

CHARLES: You will be talking on 'A Monoid For All Seasons.'


CHARLES: And then you've also got The Joy of Haskell book, which you're hacking away right now, right?


CHARLES: With that, thank you so much for both of you. Thank you all for listening. What's a good place for people to reach out for you?

JULIE: If they're on Twitter, I'm very active on Twitter so I'm @argumatronic on Twitter and my blog is also Argumatronic and that has more contact information.

CHARLES: Fantastic. We'll link to those in the show notes. For everybody else, thank you for listening. You can get in contact with us at @TheFrontside on Twitter and Contact@Frontside.io over email. We'd love to hear from you. This just in, we're running a special. If you go to our website and enter the promo code 'ELRICK20,' you can get that 20% discount on your next custom developed web application. Go check that out. Take it easy, everybody. Bye-bye.

JULIE: Bye-bye.

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