Reverse.jar

http://blog.tmorris.net/reversejar/

by henning • 16 years ago

50 39 16 years ago

blog.tmorris.net

nailer• 16 years ago

This happens, but sometimes the academic doesn't make the breadth of immediate utility for their intentions clear.

The article seems almost a direct response to the ``A statically typed language I'd actually want to use'' article: http://news.ycombinator.com/item?id=1872501

I agree wholeheartedly with the general sentiment. Even if it is a bit outdated. Type polymorphism (generics) is now well accepted.

silentbicycle4• 16 years ago

Part of the problem is that people using said languages may not see that those problems have anything in common. When somebody comes along and says, "Dude, you can automatically handle all of those edge cases at once, with one general rule!" it sounds like a bunch of mathematical jibber-jabber.

(The fact that it often is mathematical jibber-jabber doesn't help their cause, though.)

_delirium• 16 years ago

Early implementations in research languages often don't actually simplify programming, even if in principle they're a good idea, which may contribute to resistance. A and B might really both be instances of some more general abstraction C, but that does you no good if specifying abstraction C is a pain in the ass, and instantiating it to make A and B each happen is tedious and complex as well.

8ren2• 16 years ago

IMHO the difficult part is seeing the commonality of those edge cases. That requires firstly knowing about the edge cases, and secondly seeing the problem (the commonality of those cases). The final step is a solution, which is where the maths comes in (or might).

Anecdotally, it seems fairly common that maths is independently re-invented by people applying it - famously for relativity, IIRC. That's because the maths guys don't actually know about the applications.

It's a truism for our industry that if a new approach really is significantly better (eg. x10) in practice, it will be adopted. You don't need to convince people; you just beat them. OTOH, there's a common wish to over-automate: to spend a week saving a second, and then it turns out to not handle the very next case. So, some people don't like to use frameworks because they are too constricting (don't handle all the cases in practice); and some (Alan Kay) even say if you can build your own infrastructure, you should.

Mathematical ideas usually only work on their own assumptions - a difficult part is matching those assumptions to an application. Though maybe this isn't a problem for the generics example.

There's also incidental practical issues, like the need to ship, then of back-compatibility, resulting in a current Java implementation that can't express List<Circle|Rect> (you need an explicit Shape interface/superclass). Although *ML has proper algebraic data types, does C# do it properly? I don't know.

bhiggins6• 16 years ago

You know, a lot of non-academic languages are pretty crappy... like Ruby, or PHP. But I'm not impressed with languages out of academia either. I don't care about your -morphisms or fancy type systems...

alextgordon2• 16 years ago

I disagree. It's true that a lot of programming language research is impractical in the real world, but occasionally it produces gems. I'd rather have the gems than nothing at all.

The real danger is not the languages, but their proponents. Academia can't make you use Haskell, but other people can.

strlen2• 16 years ago

You know, creationism and demon possession are both quite crappy. But I'm not impressed with biology out of academia either. I don't care about your evolution or fancy germ theory...

bhiggins6• 16 years ago

Your argument is so compelling. Now I see how wrong I've been. I'll just accept everything the ivory tower says from now on, on any topic, unconditionally. Brilliant.

chc2• 16 years ago

If you've taken the time to learn Lisp and it hasn't impressed you even a little bit, you're made of more stubborn stuff than most programmers.

But most of the "non-academic" languages wind up cribbing from the academic languages anyway. For example, Python is very much a Working Man's language, but it pervasively uses not only garbage collection (from Lisp), but also list comprehensions borrowed directly from Haskell!

bhiggins6• 16 years ago

I'm impressed with lambda calculus as a mathematical formalisms and its equivalence with TMs, and I am impressed but not overly enamored with homoiconicity & metaprogramming/macros. I like conditionals. Not a fan of marketing minimal syntax but having special forms. Not a fan of cons as a a building block for everything. Not a big believer in garbage collection. And certainly not a believer that Lisp is a practical programming language for much of anything these days.

But don't let me stop you from caaaaadring away!

silentbicycle4• 16 years ago

It seems to be overwhelmed. Google cache: http://webcache.googleusercontent.com/search?q=cache:16XHnrP...

8ren2• 16 years ago

Text-only version of cache (Full version also isn't loading) http://webcache.googleusercontent.com/search?q=cache:16XHnrP...

mjw• 16 years ago

[only tangentially related to the sentiment here but:]

There is this tendency (which I can sympathise with but only to an extent) in mathematics and to an extent computer science.

"Let me solve the problem once, in as general and as abstract terms as possible. Leave the lesser minds to prove the corollaries, to apply the work. Let them take on the cognitive load of rephrasing their problems into my abstracted vocubulary in order to benefit from my vast insights and my generalised theorems."

But, crucially in software development, formal systems are designed for the human brain -- and not just individual brains but whole teams of them. Programs become as much a medium of communication between humans and other humans (of varying skillsets) as between humans and computers.

You can't escape UI work and UI considerations, I guess is the point :)

brehaut2• 16 years ago

I think this line of reasoning is why the C# team avoided the M word and introduced Linq for a range of things (sequence comprehensions, reactive programming etc) and is introducing the async syntax for more stuff in 5, even though they could all be implemented with the same more general model.

[edit] the M word is Monad

alextgordon2• 16 years ago

I don't think there's anything inherently wrong with monads, it's just that nobody's figured out how to explain them yet :) This is somewhat compounded by the awful name and Haskell's less than practical character. My guess is that they'll turn up in a new language in a few years and everyone will wonder what they did without them.

jacobolus• 16 years ago

You can’t escape UI work in math, either. The comprehensibility of the notation system is crucial to forward progress. Which makes it unfortunate that a lot of mathematical notation ends up being unnecessarily arcane, taking ideas that make perfectly clear sense graphically or intuitively and mangling them into an impenetrable tangle. And I don’t think there are enough serious challenges to bad notation: if a notation has worked for a few people trying to prove things, others too often accept it and move on.

Some of the complexity may be necessary in the name of precision, but a lot of the time it’s simply a design failure. Part of the problem may be that it doesn’t seem like mathematicians get any real training in notation design or abstraction communication. Theorem proving exercises in school almost always stress rigor over clarity of explanation: proofs in homework are always either correct or not correct, and what is tested by them is students’ comprehension of existing notation and previously developed abstractions, but there is no exercise which tests students ability to invent good new abstractions or notations.

highlander• 16 years ago

It's a balance. With overly simplistic languages, one ends up with too much code and repetition. However, when languages get more, well, 'advanced', it just gets harder to hire people who can work with it. Sure you need fewer people, but they're harder to find.

kazuya• 16 years ago

In reality, the obstacle is in realizing the need of list.reverse library, rather than in making it decent.

Reverse.jar

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