Search found 46 matches

by Porges
Sun Oct 12, 2008 5:12 am UTC
Forum: Computer Science
Topic: Reconciling side effects with lazy (non-strict) evaluation?
Replies: 12
Views: 4365

Re: Reconciling side effects with lazy (non-strict) evaluation?

A few days ago, I set out to write a prolog interpreter in Haskell (we're learning Prolog in my compsci class). Everything went swimmingly well until I realized I had to (statefully!) generate unique atoms at times. The solution was ugly: I passed around a "variable counter" in each frame...
by Porges
Sat Oct 11, 2008 12:32 am UTC
Forum: Coding
Topic: Generating an unknown number of units
Replies: 9
Views: 1813

Re: Generating an unknown number of units

If you're going to try to write something in XNA without knowing what subclassing is you're going to have issues. I suggest that you get out a couple of good books on C# and study up first :)
by Porges
Fri Oct 10, 2008 9:33 am UTC
Forum: Coding
Topic: Enumerate in LaTeX
Replies: 1
Views: 2173

Re: Enumerate in LaTeX

See this TeX FAQ: http://www.tex.ac.uk/cgi-bin/texfaq2htm ... erruptlist

You could try using the first method?
by Porges
Fri Oct 10, 2008 7:54 am UTC
Forum: Coding
Topic: How to approach difficult problems?
Replies: 25
Views: 3254

Re: How to approach difficult problems?

How to approach difficult problems? WITH HASKELL!
by Porges
Mon Sep 01, 2008 5:01 am UTC
Forum: Coding
Topic: Good programming music
Replies: 93
Views: 15915

Re: Good programming music

by Porges
Tue Aug 12, 2008 1:16 am UTC
Forum: Computer Science
Topic: Math related research in computer science
Replies: 7
Views: 2892

Re: Math related research in computer science

Category theory :D
by Porges
Sun Jun 29, 2008 1:18 am UTC
Forum: Coding
Topic: Absurd regular expressions
Replies: 37
Views: 6629

Re: Absurd regular expressions

Berengal wrote:Yeah, emails are balancing neatly on the edge of what is regular languages and what isn't.


No, they’re most definitely not regular; the nested-comments abilities see to that :)
by Porges
Sun Jun 29, 2008 1:15 am UTC
Forum: Mathematics
Topic: Your Axiom of Choice is SILLY
Replies: 60
Views: 8975

Re: Your Axiom of Choice is SILLY

What’s with all this ‘The AoC is intuitive’ crap :P I find it to be completely the opposite. :/
by Porges
Tue Jun 03, 2008 9:32 am UTC
Forum: Computer Science
Topic: XOR crypting
Replies: 22
Views: 12807

Re: XOR crypting

Locke1689 wrote:there are other methods that are more secure that use smaller key sizes


No, a one-time pad is perfect security, assuming the key is completely random, the key is as long as the data, and the key is never compromised :)
by Porges
Tue Jun 03, 2008 9:28 am UTC
Forum: Coding
Topic: Reading Filenames and etc.
Replies: 13
Views: 2152

Re: Reading Filenames and etc.

Code: Select all

find -iname "*.mp3" | sed -nre 's/^.*\/\[([^]]+)\]-([^.]+)\.[mM][pP]3$/insert into my_table values ("\1","\2")/p' > script.sql
by Porges
Mon May 26, 2008 2:41 am UTC
Forum: Computer Science
Topic: Intelligent random word generation
Replies: 7
Views: 6502

Re: Intelligent random word generation

Markov chains are popular for doing this kind of generation... see, for example, this part of the Markov chain article on Wikipedia . I did recently read a nice article on this topic; http://blog.plover.com/lang/finnpar-2.html . But of course, what you’re talking about is enforcing some kind of exte...
by Porges
Mon Apr 21, 2008 3:10 pm UTC
Forum: Coding
Topic: Computers in raptorland.
Replies: 11
Views: 2061

Re: Computers in raptorland.

What laranzu says, check out the window font; it’s Chicago.

Also a small "MPW" conveniently revealed in the top-left of the screen :)
by Porges
Mon Apr 21, 2008 5:04 am UTC
Forum: Mathematics
Topic: Do the surreal numbers provide a well-ordering for R?
Replies: 16
Views: 2641

Re: Do the surreal numbers provide a well-ordering for R?

you can't construct a well-ordering of the reals without invoking the Axiom of Choice in one of its guises. When I was thinking about it, it was from the other point of view; what is the well-ordering? Yes, given two sign-expansions, you can create a lexicographic order, and that is a total order. ...
by Porges
Sun Apr 20, 2008 9:15 am UTC
Forum: Mathematics
Topic: Do the surreal numbers provide a well-ordering for R?
Replies: 16
Views: 2641

Re: Do the surreal numbers provide a well-ordering for R?

Ah yes, so it’s only lexicographic when the items have the same number of +/-. You need to take length into consideration as well, so that x<y if the number of of +/-s in x is < that in y, or {insert lexicographic ordering rules}. Equivalently you could left-pad the shortest one with a third charact...
by Porges
Sun Apr 20, 2008 1:15 am UTC
Forum: Mathematics
Topic: Do the surreal numbers provide a well-ordering for R?
Replies: 16
Views: 2641

Re: Do the surreal numbers provide a well-ordering for R?

Yes, by trivial I meant lexicographic. I originally wrote that but reverted to the word ‘trivial’ for some reason. It made the sentence flow better :P

Anyway, thanks Token/Antononfire, that cleared it up for me :)
by Porges
Sat Apr 19, 2008 1:16 pm UTC
Forum: Mathematics
Topic: Do the surreal numbers provide a well-ordering for R?
Replies: 16
Views: 2641

Do the surreal numbers provide a well-ordering for R?

I was just doing some random reading on the Axiom of Choice and its implications, and the various comments on how the well-ordering principle doesn’t seem to have been effected on R... and I thought of this; Since surreal numbers contain R, and can be written in sign-expanded form (e.g. +++--), and ...
by Porges
Thu Apr 17, 2008 7:17 am UTC
Forum: Coding
Topic: Physical units as a type?
Replies: 15
Views: 1738

Re: Physical units as a type?

Haskell has the Dimensional library. It’s completely statically checked :)
by Porges
Wed Apr 16, 2008 11:54 am UTC
Forum: Coding
Topic: Arbitrary length parametrization
Replies: 24
Views: 2772

Re: Arbitrary length parametrization

If you just want Futures you could take a look at the .NET parallel extensions library :)
by Porges
Wed Apr 16, 2008 11:47 am UTC
Forum: Coding
Topic: Is there a language that does a < (b & c & d)?
Replies: 40
Views: 5373

Re: Is there a language that does a < (b & c & d)?

you can do this in factor: { 4 8 10 } [ 3 > ] all? and this in javascript: [4,8,10].every(function(n){return 3<n}) and this in c#: (new List<int>(new int[3]{4,8,10})).TrueForAll(new Predicate<int>(delegate(int i){return 3<i;})) and something similar in a lot of other languages... Make that C# examp...
by Porges
Wed Apr 16, 2008 6:09 am UTC
Forum: Coding
Topic: Is there a language that does a < (b & c & d)?
Replies: 40
Views: 5373

Re: Is there a language that does a < (b & c & d)?

Perl has Superposition which allows:

Code: Select all

3 < 4 & 8 & 10


There are several superposition-style modules for Haskell, or you could just do:

Code: Select all

all (3<) [4,8,10]
by Porges
Wed Apr 16, 2008 6:02 am UTC
Forum: Individual XKCD Comic Threads
Topic: 0411: "Techno"
Replies: 150
Views: 37587

Re: "Techno" Discussion

I assume he was referring to this http://gizmodo.com/gadgets/announcements/hard-drive-dying-dance-track-winner-151666.php contest with the crashed hard drive. Listen to the runners up, too; they are actually pretty good. Techno tech-tech-tech-echno-echno-techno ftw. Where can I find a mirror? Odeo ...
by Porges
Mon Apr 07, 2008 8:40 am UTC
Forum: Coding
Topic: "Mission: learn socket programming" going.... not so good
Replies: 8
Views: 1869

Re: "Mission: learn socket programming" going.... not so good

TBH you’d be better off starting in C# :)
by Porges
Sun Apr 06, 2008 9:35 pm UTC
Forum: Computer Science
Topic: Compiler Book?
Replies: 16
Views: 3801

Re: Compiler Book?

I own "Modern Compiler Design" published by Wiley, written by {Dick Grune, Henri Bal, Ceriel Jacobs, Koen Langendoen}.

It covers a whole bunch of stuff, including compiling Prolog & Haskell, along with modern techniques like attribute grammars.
by Porges
Mon Oct 15, 2007 7:20 pm UTC
Forum: Coding
Topic: How should I exit this loop? Java style question.
Replies: 14
Views: 4229

Re: How should I exit this loop? Java style question.

This:

Code: Select all

return Bricktype.valueOf("TYPE_" + keyboard.nextInt());

is yucky. Can’t you cast integers to enums in java? I haven’t used it for a while...

As to your original question:
Why not have your method return a valid BrickType, or NULL if one doesn’t match?
by Porges
Thu Oct 11, 2007 12:25 am UTC
Forum: Mathematics
Topic: Favorite Mathematical Equation
Replies: 87
Views: 21621

Re: Favorite Mathematical Equation

e^{i\pi}+1=0

This question is obvious to anyone with even the smallest sense of beauty ;)

It has:
- exponentiation
- multiplication
- addition
- equality
- e
- pi
- zero
- one

... which is more than enough to do any true mathematics ;)
by Porges
Wed Oct 10, 2007 6:17 am UTC
Forum: Coding
Topic: Fizzbuzz!
Replies: 81
Views: 233338

Re:

Drostie wrote:the type of (A ? i : "stuff") is simply Object, since that's the lowest class which has both of those as subclasses


If you want to get technical, it's the join, or least upper bound. Since Java doesn't have a particularly rich type system this is always Object :p
by Porges
Fri Aug 24, 2007 11:02 pm UTC
Forum: Computer Science
Topic: Computer Science in High School
Replies: 78
Views: 12727

Magitek wrote:Is Turing even a language besides what's formalized as a Turing Machine? What would you learn in that class besides Turing machines for proving algorithms?


Yes :)

...and I'm guessing they wouldn't even have approached the second question.
by Porges
Fri Aug 24, 2007 11:00 pm UTC
Forum: Mathematics
Topic: I wonder know how interesting these formulas are
Replies: 7
Views: 2122

Re: I wonder know how interesting these formulas are

[quote="~J-@Ã
by Porges
Tue Aug 21, 2007 10:00 pm UTC
Forum: Science
Topic: Physics of Muscles
Replies: 32
Views: 4505

Well, the above work would show (to some approximation, good or bad) how much power is actually put into the movement. But I can't imagine that the muscles are 100% efficient (and of course the 2nd law of Thermodynamics would agree), so my question is how efficient is a real muscle? Google gives Wi...
by Porges
Tue Aug 21, 2007 8:18 am UTC
Forum: Mathematics
Topic: What level of mathematics do people know on this forum?
Replies: 63
Views: 9612

SpitValve wrote:You at Massey Wellington then?


Yup. :)
by Porges
Tue Aug 21, 2007 5:55 am UTC
Forum: Mathematics
Topic: What level of mathematics do people know on this forum?
Replies: 63
Views: 9612

NZ +1. :D I'm doing an engineering degree, so the mathematics is more based along the lines of "This is what you need to do That". That said, I'm finding myself more and more interested in the theoretical side -- which I like, despite my hatred of the subject at college (high school for y...
by Porges
Sun Aug 12, 2007 12:19 am UTC
Forum: Mathematics
Topic: Natural complements - C and S
Replies: 29
Views: 4165

In category theory, for every s--- there's a co-s--- :)
by Porges
Sat Aug 11, 2007 10:29 pm UTC
Forum: Computer Science
Topic: Building logic gates
Replies: 30
Views: 11766

You could try starting here and clicking around: http://en.wikipedia.org/wiki/AND Most of the logic gate pages have circuit diagrams. :) I can also recommend the book "Code: The Hidden Language of Computer Hardware and Software". ( link [shortened] ) It starts off with simple relays/trans...
by Porges
Sat Aug 11, 2007 10:25 pm UTC
Forum: Mathematics
Topic: Other kinds of math
Replies: 17
Views: 3567

I'm not sure exactly what you mean by "other kinds". I'm going to assume you mean "different from ZFC", even if you don't know what ZFC is :wink: An interesting alternative is 'constructive' or 'intuitionistic'* mathematics, in which we don't have the 'law of the excluded middle'...
by Porges
Sat Aug 11, 2007 10:04 am UTC
Forum: Computer Science
Topic: Building logic gates
Replies: 30
Views: 11766

You could try starting here and clicking around: http://en.wikipedia.org/wiki/AND Most of the logic gate pages have circuit diagrams. :) I can also recommend the book "Code: The Hidden Language of Computer Hardware and Software". ( amazon ) It starts off with simple relays/transistors, bui...
by Porges
Fri Aug 10, 2007 2:02 am UTC
Forum: Coding
Topic: Couple Java programs.
Replies: 23
Views: 3512

Caesar> main My secret is more secret than yours. hv uJFrJI bu zCrJ uJFrJI ItpL vCXru. Key: fromList [('A','Z'),('B','Y'),('C','o'),('D','d'),('E','q'),...] Can you break that? Or cut some out? It's not like we don't get the idea, and you broke the width of the thread, requiring horizontal scrollin...
by Porges
Thu Aug 09, 2007 7:20 am UTC
Forum: Coding
Topic: Ideas on improving security for my program?
Replies: 22
Views: 3632

It's pretty much impossible to prevent, and I'd say that the bit-twiddling attack is much more likely to be carried out than the first (because of the hassle involved).
by Porges
Thu Aug 09, 2007 2:20 am UTC
Forum: Coding
Topic: Couple Java programs.
Replies: 23
Views: 3512

I'm trying to get to know haskell better, so here's the Caesar one: import Data.Map hiding (map) import MyPrelude (translate, shuffle) main = do let alphabet = ['a'..'z'] ++ ['A'..'Z'] shuffled <- shuffle alphabet let translationKey = fromList $ zip alphabet shuffled message <- getLi...
by Porges
Thu Aug 09, 2007 1:47 am UTC
Forum: Coding
Topic: Random Linux stuffs, comparisons to Windows, and other ...
Replies: 26
Views: 4706

or you could compress this to: find . -name "*.c" -exec grep foo {} \; this should take care of weird chars in filenames, although I didn't check. I can't check (computer down at the moment), but I think the {} need to be quoted: "{}" for spaces and suchlike.
by Porges
Wed Aug 08, 2007 8:36 pm UTC
Forum: Coding
Topic: Couple Java programs.
Replies: 23
Views: 3512

Hench wrote:Porges: It will enter the center loop iff key[random] is already taken; it's a protection against changing a key that was already set. In fact, it will enter it every time the for() iterates, except the first time.


Doh. That's what I get for reading code before my morning coffee ;p

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