I want to fix programming • Hacker News Board

Re: I want to fix programming

#101

Post by dmitriy_ko » Wed, Jan 25, 2012, 3:25 AM UTC

munificent wrote: post #85

pfraze wrote: post #71

Earlier quoted context omitted.

What if you created a declarative language which allows you to override the algorithms in a functional/imperative? You could create a public algorithm repo that auto-pulls into your local machine on setup. Could search for algorithms by declarations. That would be a lot of reuse.

> What if you created a declarative language which allows you to override the algorithms in a functional/imperative? We have that. They're called libraries. If I need to sort a collection, I don't write an imperative chunk of code, I just do: sort(myCollection) Looks pretty declarative to me.

The issue here is that function definition doesn't tell what the function does. So you may have hundred implementations of sorting algorithms in different libraries, and neither compiler nor the IDE know that they all do the same thing. So when you write

sort(myCollection)

you are still referring to one particular set of instructions. The system parent poster envisions (the way I understand it) would be along those lines:

* User gives SPECIFICATION of sort, along the lines OP writes about in his blog.

* Other contributors provide various implementations which satisfy the specification. Such system would either have to auto-prove that implementation meets specification or just trust contributors that it does.

* Then in your code you can write sort(myCollection) and the system would pick the best implementation.

Re: I want to fix programming

#102

Post by derekp7 » Wed, Jan 25, 2012, 3:26 AM UTC

jng wrote: post #24

batista wrote: post #21

"Programming is broken. Completely broken." What something starts like this it usually translates to: "I don't understand pragmatic hardware/complexity/market etc constaints and engineering compromises".

Might be. Hopefully not. I have done a huge amount of programming though, so it's not like the reflection comes from ignorance. Under the mess of spaghetti code that anything out there is now, I see a clean structure of code trying to come out. I want to help it come out to the surface.

Generally, what I've found is the reason for the big pile of mess is not that the methodology is wrong, but quite frankly the programmer didn't know what needed to be done until the program was completed. Even with a complete set of requirements, if you are writing anything of any complexity then by definition it hasn't been done before. But you can usually take an existing program, re-define the specification, and re-write the code in a much cleaner and correct fashion (assuming you avoid the temptation to add new features at the same time).

Re: I want to fix programming

#103

Post by rmcclellan » Wed, Jan 25, 2012, 3:52 AM UTC

3pt14159 wrote: post #89

ChristianMarks wrote: post #64

The problems the OP wants to solve are formally undecidable and reducible to the halting problem. 1. Given a formal specification, find a program that meets the specification. 2. The apparently simpler problem of checking whether a given program meets a specification. Both are undecidable. That said, there is an extensive literature on practical approaches to this problem. They generally suffer from intractability. h…

I have a question about this Christian, assume that we can accurately model an atom with a computer and then we uploaded a human into the computer, wouldn't the computer then be able to either solve the problem or report that the problem is unsolvable? I understand the halting problem but isn't there some kind of meta check that a sufficiently complex system could output?

Sure, having a virtual human try to solve the problem would be pretty good. However, even the virtual human would never be able to check the specification correctly for every possible program due to the halting problem. In particular, no matter what the specification was, a malicious user could create a program that mimics the virtual human's response and then does the opposite thing (it's the same basic proof that the halting problem is undecidable). By construction then, the virtual human would answer incorrectly when asked whether or not the program matches the specification.

So, academically, even the "virtual human" approach doesn't work since it doesn't answer correctly for every single program. Practically, you're right, having a virtual human would be good enough for most uses.

That said, I wouldn't want to use a virtual human for this due to ethical concerns :-).

Re: I want to fix programming

#104

Post by bfrs » Wed, Jan 25, 2012, 4:10 AM UTC

Relevant stuff from SICP [1]:

"The contrast between [a mathematical] function and [a computing] procedure is a reﬂection of the general distinction between describing properties of things and describing how to do things, or, as it is sometimes referred to, the distinction between declarative knowledge and imperative knowledge. In mathematics we are usually concerned with declarative (what is) descriptions, whereas in computer science we are usually concerned with imperative (how to) descriptions.

...an important current area in programming-language design is the exploration of so-called very high-level languages, in which one actually programs in terms of declarative statements. The idea is to make interpreters sophisticated enough so that, given “what is” knowledge speciﬁed by the programmer, they can generate “how to” knowledge automatically. This cannot be done in general, but there are important areas where progress has been made."

[1] http://mitpress.mit.edu/sicp/full-text/book/book-Z-H-10.html...

Re: I want to fix programming

#105

Post by arohner » Wed, Jan 25, 2012, 5:09 AM UTC

gruseom wrote: post #60

Ygor wrote: post #18

For those who haven't read it yet, this paper has a lot to say about the cause of programming complexity, Out of The Tarpit: http://web.mac.com/ben_moseley/frp/paper-v1_01.pdf They say that the only essential complexity is the one inherent to the problem the program is trying to solve. Everything else is just here because we haven't yet found the methodology or invented the tools to battle it. They also describe an i…

this paper has a lot to say about the cause of programming complexity, Out of The Tarpit This paper is highly regarded by some smart people, but every time I've tried to read it I've seen nothing of much value - only some obvious platitudes about complexity (including the bit about complexity being intrinsic to the problem vs. just the implementation), a lot of architectural gobbledygook (complete with boxes-and-line…

Clojure.

Clojure's lispy (simple implementation, syntax), FP (reduced state), easier concurrency, agents + stm are all influenced by this paper.

Re: I want to fix programming

#106

Post by jowiar » Wed, Jan 25, 2012, 5:13 AM UTC

Two quick things jump out at me: (1) This is TDD, without the implementation part of it. (2) There have to be some halting problem issues in here. It's actual realm of usefulness is constrained somewhere, though I'm not exactly sure where.

That said, I've worked with modeling languages along the lines of GAMS that work in this sort of manner. Define a problem - a set of constraints - equations, inequalities, parameters, and the like - push a button, and out pops a solution. Damn useful.

Re: I want to fix programming

#107

Post by gruseom » Wed, Jan 25, 2012, 5:23 AM UTC

arohner wrote: post #105

gruseom wrote: post #60

Earlier quoted context omitted.

this paper has a lot to say about the cause of programming complexity, Out of The Tarpit This paper is highly regarded by some smart people, but every time I've tried to read it I've seen nothing of much value - only some obvious platitudes about complexity (including the bit about complexity being intrinsic to the problem vs. just the implementation), a lot of architectural gobbledygook (complete with boxes-and-line…

Clojure. Clojure's lispy (simple implementation, syntax), FP (reduced state), easier concurrency, agents + stm are all influenced by this paper.

That seems like a huge stretch. Lisp has nothing to do with that paper, and minimizing state and complexity could hardly be more obvious design concerns. The concurrency aspect I can't comment on, but it's not a major theme there either.

Perhaps I just don't get it, but I'm a little miffed at having tried several times to absorb the gems of wisdom in that paper and come up with nothing that isn't obvious (even the idea of functional programming over relational data is obvious) and that couldn't have been said less pretentiously in easily a tenth of the space - ironically, for a paper about minimizing complexity.

Re: I want to fix programming

#108

Post by chj » Wed, Jan 25, 2012, 5:55 AM UTC

Sorting is not a good subject for discussing an advanced/intelligent programming language. Try to solve hard problems which are difficult to solve with current languages.

Declarative programming can be very helpful in domain specific tasks. You start with a set of constraints that the computer can understand, and then the core AI will automatically give you the answer. Perhaps then a lot of common people can start to tell computer to do things for them without writing a single line of code, but they need to talk in the languages that computer can understand.

Re: I want to fix programming

#109

Post by ryanmolden » Wed, Jan 25, 2012, 6:36 AM UTC

Have you read Elements of Programming by Alexander Stepanov (he of STL fame) and Paul McJones? They take a similar approach as your examples except instead of declarative generation of code they break things down to very rudimentary mathematical definitions of operations and concepts and then build more complexity by bolting them together. Not terribly different than normal programmatic problem decomposition, but they tend to take it a little lower (or perhaps to a higher level of abstraction).

Re: I want to fix programming

#110

Post by nandemo » Wed, Jan 25, 2012, 6:59 AM UTC

jerf wrote: post #55

So, over the years I've played with many things that claim to be "declarative", and here's why I now shy away from them like the plague. There's no such thing as "declarative". No matter what you type into the computer, at some point it's going to turn into instructions that do the thing you want done. Trying to create a declarative language is a way of making it extraordinarily opaque as to what the machine is actua…

> Trying to create a declarative language is a way of making it extraordinarily opaque as to what the machine is actually going to do. It looks great in four lines, it crashes and burn on any real sized problem,

Erlang, Haskell and Ocaml are examples of declarative languages, and they all have been used to solve very real-sized problems: telecommunication switches, compilers, trading systems, a window manager, etc.

It amazes me how the argument above is still repeated (often followed by "but those systems don't count, give me an example of X".)