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Dijkstra on Haskell and Java (2001)

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Re: Dijkstra on Haskell and Java (2001)

#161

Post by xradionut »

chongli wrote: post #154
kabouseng wrote: post #14

I would guess Haskell would be perfect if the goal is to produce academics. But if most of your students are destined for industry, Haskell is in my opinion the absolute worst language. - You'll probably get a high drop out rate because of the complexity (recursion, pure / first class functions etc). - You rely that your students already have experience at high school with imperative languages - The industry by far s…

- The industry by far still don't use functional languages. Flat-out wrong. The world's most popular language (in terms of lines of code, number of programmers and companies using it) is a functional language: JavaScript.

Cheap crappy beer and junk food are popular too.

Re: Dijkstra on Haskell and Java (2001)

#162

Post by angersock »

616c wrote: post #105
stiff wrote: post #33

To me there seems to be something wrong with using as the first language something that depends on a very, very complicated runtime and execution model to run on the hardware we currently are using. This way people end up viewing programming languages as some God-given black box and not just something another computer program written by another person provides for you. I think CS students should instead start by lear…

Your idea about going from architecture to programming in the other way of traditional curricula, in my opinion, has a lot of merit. Other seem to agree. An Israeli professor, Noam Nisan, created a course specifically for this purpose, now branded even more popularly as Nand2Tetris course and book.[0] Why did he teach something obvious like this? From the site: "Why Bother? Because many CS students don't understand h…

One of the best books I've seen takes this approach:

http://www.amazon.com/Code-Language-Computer-Hardware-Softwa...

~

Starting from either extreme (pure maths or pure electrical engineering) is quite healthy--starting in the middle, though, does a disservice.

Re: Dijkstra on Haskell and Java (2001)

#163

Post by macspoofing »

stiff wrote: post #136
macspoofing wrote: post #134

Earlier quoted context omitted.

>To me there seems to be something wrong with using as the first language something that depends on a very, very complicated runtime and execution model to run on the hardware we currently are using. Computer Science is more than just programming. There is a lot of formal theory underpinning this area that has nothing to do with circuits, transistors and microprocessors. CS departments shouldn't just be concerned wit…

The bulk of the formal CS theory is much more related to the imperative model than it is to the functional one, see https://news.ycombinator.com/item?id=7024731

So what. What does that have to do with anything? We're not talking about imperative models vs functional ones. And even if we did, imperative programming has nothing to with what you're suggesting. For example, it is always preferable to explore and study algorithms and data structures in higher-order languages so that you don't get bogged down in irrelevant details.

CS departments are going to structure their programs in multitudes of ways. My point is, there's nothing wrong with not being concerned about teaching first-year undergrads microprocessor architecture and the nitty-gritty of memory management and OS design, but instead starting at another end of the Computer Science spectrum. Being exposed to lambda calculus and functional programming early and even viewing the Haskell run-time as some 'God-given black box' is not a bad idea.

Re: Dijkstra on Haskell and Java (2001)

#164

Post by johmacindu »

jadyoyster wrote: post #90
mseebach wrote: post #81

Earlier quoted context omitted.

> might leave behind students that have not yet been exposed to any programming And good riddance. If you make it to university without exposing yourself to your subject as a matter of passion (and few subjects are more easily approached by hobbyists than programming) you're going to waste your time there. University is a not a "school" you attend for learning a subject. You can't show up for English Literature if yo…

Plenty of computer science students at my (SICP-using) university had never programmed before attending, yet they're great at it. Your attitude is especially damaging to female students, who are even less likely to lack programming experience. Computer science isn't even about programming all that much. > You can't study Economics if you've never heard of Keynes. Have you ever even been to a university?

Surely you won't get onto an Economics degree course if you haven't already studied economics in high school? I'm from the UK and there you can study Economics from 15.

Also, surely the interview will ask you about your background knowledge of economics, and if you didn't know who Keynes was you're unlikely to get an offer.

Re: Dijkstra on Haskell and Java (2001)

#165

Post by angersock »

btian wrote: post #42
stiff wrote: post #33

To me there seems to be something wrong with using as the first language something that depends on a very, very complicated runtime and execution model to run on the hardware we currently are using. This way people end up viewing programming languages as some God-given black box and not just something another computer program written by another person provides for you. I think CS students should instead start by lear…

I disagree. The whole point of abstraction is that you don't have to care about the underlying mechanisms (although most non-trivial abstractions are leaky as Joel Spolsky has written about). For instance, someone who writes assembly should not have to know how a transistor works. A course in introductory programming similarly should not be about how a processor works.

In theory, there's no difference between theory and practice--in practice, there is.

All abstractions in computers and software engineering are leaky, and you either learn enough to overcome the limitations of real machines or you learn to regret your ignorance.

Re: Dijkstra on Haskell and Java (2001)

#166

Post by AnimalMuppet »

scott_s wrote: post #120
roskilli wrote: post #104

Earlier quoted context omitted.

That may be true, but it will not be until you descend the stack you start to code like someone who understands what they are doing. For instance I started off with PHP in high school and was using arrays with each entry as a string with a colin in it to split a key and value apart. So essentially I created the worlds worst hashmap and each lookup was O(N) - not to mention the actual string splitting I was doing on e…

What's the bottom? You clearly have something in mind, but why not starting with logic gates and work up to assembly? That is also a valid approach, and it works up to what you consider the bottom of the stack. I do computer systems research. I am a big proponent of knowing how computer systems work. But I think people have an unhealthy fetish for how we start learning. You start once. You learn the rest of your life…

Bah. The bottom of the stack is quantum mechanics and solid state physics. From there, you learn how individual transistors work. From that, you build up to logic gates.

I actually know something about those levels. But in 25 years as a professional programmer, the lowest level I've ever actually needed to use was at the gate level (PAL equations to generate chip selects by decoding addresses - if it wasn't in a PAL, it would be just equations).

Re: Dijkstra on Haskell and Java (2001)

#167

Post by twic »

tel wrote: post #152
dded wrote: post #118

Earlier quoted context omitted.

> The bottom-up people [...] only add abstractions [later] I don't think bottom-up verses top-down are like political camps. I think it's more innate, like right-brained vs. left-brained. I can't understand abstractions till I first understand the lower level. I could never learn algebra without first learning arithmetic. (BTW, I'm old enough to have lived through the New Math philosophy which insisted that every gra…

As someone who's strongly in the "top down" camp by observation, I'm about to refute an interpretation of what that means. Everyone who's learned Haskell really well understands exactly that you learn monads by example, not abstraction. Abstractions need both motivation and "point samples" which describe good reasons for their particular brand of abstract behavior to be meaningful. I don't think at all that the "top…

Same thing happens with design patterns. It probably happens with all sorts of non-obvious but powerful ideas. Hmm. Any sufficiently advanced learning is indistinguishable from madness?

Re: Dijkstra on Haskell and Java (2001)

#168

Post by yongjik »

RyanZAG wrote: post #144
danielweber wrote: post #128

Earlier quoted context omitted.

That might (might) explain a tiny college, but it's not a reasonable explanation for universities with huge endowments to switch from Haskell to Java.

Yet they swapped - which is either explained by some love for java (unlikely) or that "more money is more good" even with a huge endowment.

Well yes it is easily explained by some love for java, why would that be so unlikely?

Computer Science is a diverse field, and not every CS professor considers mutable global variable an evil to be purged. (In fact, the majority of CS professors can't be bothered to think about such matter. They're busy tuning their neural networks, photorealistic simulation of snowflakes, improvements to TCP or whatever their particular research interest is. The answer to "Java or Haskell?" for them is "whatever that suits my need.")

Re: Dijkstra on Haskell and Java (2001)

#169

Post by angersock »

jimktrains2 wrote: post #94
stiff wrote: post #33

To me there seems to be something wrong with using as the first language something that depends on a very, very complicated runtime and execution model to run on the hardware we currently are using. This way people end up viewing programming languages as some God-given black box and not just something another computer program written by another person provides for you. I think CS students should instead start by lear…

> CS students I think CS students should be taught computer science, not software engineering.

Pure theoretical computer science is just a weird offshoot of discrete mathematics, mostly, right?

The central concession of Computer Science as correctly taught is that a purely theoretical approach will not enable you to do anything of use--while you're still finishing your existence proof, some asshole with Ruby and AWS has already gotten it working "good enough" to get funding and make people happy through trial and error.

Software Engineering is too limited a discipline itself, because it is mostly project management, architecture, and planning--mostly vocational skills learned through (hard-earned) experience.

Computer Engineering is too focused on electrical engineering problems: you can guarantee how data is transferred between registers and how fast signals fan out and whatnot, but what the data is or how it is being transformed matters not.

Computer Science as taught combines both of these things in hopes of producing students that can reason about what they're doing (like mathematicians) and plan projects to execute on that (like software engineers) and to appreciate when actual hardware will choke on it (like computer engineers).

It's a blended subject for a bloody good reason.

Re: Dijkstra on Haskell and Java (2001)

#170

Post by AnimalMuppet »

angersock wrote: post #165
btian wrote: post #42

Earlier quoted context omitted.

I disagree. The whole point of abstraction is that you don't have to care about the underlying mechanisms (although most non-trivial abstractions are leaky as Joel Spolsky has written about). For instance, someone who writes assembly should not have to know how a transistor works. A course in introductory programming similarly should not be about how a processor works.

In theory, there's no difference between theory and practice--in practice, there is. All abstractions in computers and software engineering are leaky, and you either learn enough to overcome the limitations of real machines or you learn to regret your ignorance.

Or you learn to claim that you don't actually care about the difference, because you're a theorist. That means that most of the world ignores you as irrelevant, though.
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