00:08:08 -!- augur has joined. 00:15:02 -!- Slereah has joined. 00:16:09 -!- Slereah_ has quit (Ping timeout: 260 seconds). 00:16:34 -!- augur has quit (Remote host closed the connection). 00:33:21 -!- ais523 has quit (Remote host closed the connection). 00:34:03 Sgeo: upeano spacedoot. 00:34:40 kallisti, my notifier hasn't gone off, therefore I assume you're lying 00:34:58 -!- Jafet has joined. 00:36:17 Sgeo: your loss 00:36:30 -!- Sgeo has left ("Leaving"). 00:36:33 -!- Sgeo has joined. 00:36:49 lordi \m/ 00:36:51 just sayin' 00:36:57 Sgeo: I guess you'll just never know how AWESOME this PUMPKINS are. 00:37:14 actually the video for blood red sandman gave me the boots: \m/ \m/ 00:37:15 `\o/´ 00:37:15 | 00:37:15 /'¯|_) 00:37:15 (_| 00:37:18 kallisti, or, you may in fact be delayed in seeing the latest updates 00:37:29 Sgeo: no I've seen that 00:37:31 Because we saw pumpkins recently, but that was a while ago 00:37:39 THERE ARE MORE PUMPKINS 00:37:40 The pumpkins update 00:43:38 -!- pikhq_ has joined. 00:43:51 -!- pikhq has quit (Ping timeout: 258 seconds). 00:47:41 mmm cornbread. 00:47:42 so 00:47:43 fucking 00:47:44 good 00:48:07 -!- sebbu2 has quit (Ping timeout: 248 seconds). 00:51:12 -!- sebbu2 has joined. 00:51:13 -!- sebbu2 has quit (Changing host). 00:51:13 -!- sebbu2 has joined. 00:55:46 I made so that some Haskell functions can have Show; it works you can type maybe (False, True) (join (,)) in GHCi and it tells you the output Nothing -> (False, True) Just False -> (False, False) Just True -> (True, True) 00:56:01 If the type is ambiguous it assumes you mean () 00:57:01 -!- DCliche has quit (Quit: You are now graced with my absence.). 00:59:37 > succ 01:01:36 -!- copumpkin has joined. 01:02:13 http://upload.wikimedia.org/wikipedia/en/math/a/5/e/a5e707d8d73a8dc420acfb9cb8794622.png 01:02:28 can someone explain this notation? it's a "family of sets" 01:02:42 which, if I understand correctly, is a multiset of sets. 01:07:23 if I understand correctly it's saying that the subsets are basically indexed by an integer or something? 01:09:01 A choice function is a function f, defined on a collection X of nonempty sets, such that for every set s in X, f(s) is an element of s. 01:09:08 The way i read it, there are some sets S for every i in set I, but that's somewhat loose and probably dodgy as an interpretation. Is there any context that would help? 01:09:15 -!- derdon has quit (Remote host closed the connection). 01:09:19 For any set X of nonempty sets, there exists a choice function f defined on X. 01:09:26 oh okay... axiom of choice now makes sense. 01:10:14 http://en.wikipedia.org/wiki/Axiom_of_choice 01:10:24 I see what the subscript i is for now. 01:11:24 ah, cool 01:15:54 I was going to say that restricts the sets to being countable, but I guess "I" could be real numbers here so not necessarily. also the mapping function I -> S is not necessarily bijective I think. 01:16:16 http://en.wikipedia.org/wiki/Indexed_family 01:21:35 -!- copumpkin has quit (Quit: Computer has gone to sleep.). 01:37:53 -!- Jafet has quit (Quit: Leaving.). 01:38:42 > let x = True in not x || x 01:38:56 ....no lambdabot? 01:39:01 NOOOOOOOOOOOOOO 01:39:56 let x = True in not x && x 01:39:57 False 01:40:09 Haskell: not a fan of intuitionism. 01:40:16 (ha ha ha) 01:41:06 of course Maybe Bool gives you a three-valued logic, in which you could probably say that not x || x is unknown (aka Nothing in this construction) 01:41:31 or well, that not x || x /can/ be unknown, depending on x. 01:43:28 on a related note 01:43:33 http://lonelynerdsinfedoras.tumblr.com/ needs more Gregor 01:44:34 kallisti, intuitionism? 01:45:08 yes, a kind of mathematical constructivism 01:45:16 What would the result of not True && True be in intuitionism? 01:45:45 http://en.wikipedia.org/wiki/Intuitionistic_logic 01:46:42 * kallisti is still learning so does not have an answer yet :P 01:49:04 well I think not True && True is False 01:49:17 but not p && p cannot in general be proven (???) 01:51:40 ok quick question, what would be a good scheme standard to implement? 01:52:04 Does R7RS exist? 01:52:17 I've heard bad things about R6RS 01:52:18 i believe so 01:52:21 wait uh 01:52:46 it's got its first draft 01:52:59 but yeah i have heard bad things about versions after R5RS 01:54:06 I've heard bad things about people who hold strong opinions about scheme standards. 01:54:46 "The R6RS standard has caused controversy because it is seen to have departed from the minimalist philosophy." 01:55:34 that is not necessarily a bad thing. But I don't know anything about R6RS 01:56:20 -!- Jafet has joined. 01:56:52 -!- Vorpal has quit (Ping timeout: 244 seconds). 02:01:17 -!- Klisz has joined. 02:01:43 -!- MDude has quit (Ping timeout: 248 seconds). 02:07:26 -!- MSleep has joined. 02:12:44 and i just found a weird bug in wla-dx 02:13:02 if you attempt to include a completely empty file, it crashes 02:13:06 add a newline, it's happy 02:14:12 GreaseMonkey: that doesn't sound too weird. 02:14:45 they probably just overlooked the possibility of the empty file or something? 02:14:55 something like that 02:14:58 -!- zzo38 has quit (Remote host closed the connection). 02:15:33 what about files that contain characters but no trailing newline? 02:15:52 no crash 02:16:04 ah. yeah that's weird. 02:45:07 Hm, I'm pondering this one problem. Implement a binary semaphore. The only atomic operation you're allowed is a swap operation: swap(x,y) atomically swaps the values of *x and *y. 02:45:56 -!- TeruFSX has joined. 02:46:56 Arbitrarily many threads could be running at any time. They can sleep, they can revive each other, and they can interact with each other's memories. 02:47:28 memories? 02:47:42 Yeah. They use shared memory. 02:47:57 Oh, was thinking of the other definition of memory 02:48:12 Which might require Feather to implement? 02:48:17 >:D 02:48:48 * Sgeo is not thinking too clearly right now 02:49:26 My original thought was for the semaphore to be represented with a variable. The variable contains 0 when the semaphore is available, and 1 when it's unavailable. To try to procure the semaphore, a thread prepares a variable containing the number 1, and atomically swaps it with the semaphore variable. 02:51:42 If the thread gets a 0 from this swap, it successfully got the semaphore. If it gets a 1 from the swap, it did not. 02:51:49 What's the problem with that, unless you have a rogue threat deliberately messing with other threads? 02:52:05 *thread 02:52:13 The problem with that is that there's no way to block on a semaphore. If you want to procure the semaphore, and it's unavailable, you have to busy loop. 02:53:29 You want to give out the semaphore in fifo order? 02:54:33 Jafet: well, I want to give it out in *some* order. If thread A procures a semaphore, then thread B tries to procure it, then thread A vacates it, then it should somehow wind up in B's possession. 02:54:36 You could probably implement a queue with atomic swaps 02:54:56 -!- TeruFSX_ has joined. 02:55:00 I've managed to create a queue that goes in the wrong direction. Each thread has a pointer to the thread before it in line. 02:55:01 You don't have a thread notification mechanism; how do you even do that? 02:55:36 Unfortunately, once you're done with a semaphore, what you need to do is give it to the thread *after* you in line. 02:55:52 Jafet: well, they have shared memory. To talk to a sleeping process, you change its variables and wake it up. 02:56:03 Okay, so you do assume a notification mechanism. 02:56:19 Well then, you should turn your queue the right way round, I guess. 02:56:20 -!- TeruFSX_ has quit (Read error: Connection reset by peer). 02:56:38 Yes, quite. 02:57:09 The way the queue is built is... more or less the same as my original thought above. To try to procure the semaphore, you swap your own thread ID into the semaphore variable. 02:57:11 -!- TeruFSX_ has joined. 02:57:24 Either you get a 0, meaning the semaphore is yours, or you get the ID of the guy before you in line. 02:58:30 What you could do is have each thread reserve a location in its memory, then write the memory address to the semaphore. The next thread writes its address to that address. 02:58:31 -!- TeruFSX has quit (Read error: Connection reset by peer). 02:58:51 Er, writes its thread-id to that address. 02:59:27 What if two threads both read the semaphore variable at the same time, and then both write in their addresses at the same time? 03:00:02 I guess right after you swap, you can give guy-before-you your thread ID. But what if guy-before-you tries to use your thread ID right before you give it to him... 03:00:10 Well, you'd need a small busy-loop while each thread atomically acquires its place in the queue. 03:00:43 I don't think there's any way around that. 03:01:53 Suppose that the zero address is invalid. Then a thread can lock the semaphore by swapping it with zero, add itself to the queue, and swap its memory address to the semaphore. 03:03:48 Hm. Suppose that two threads try to swap zero into the semaphore at the same time. 03:04:36 One of the threads will get a zero out. This means it can't proceed, so it has to sleep. Who wakes it up? 03:04:56 tswett: "queue that goes in the wrong direction" like a stack? :> 03:05:19 kallisti: that... yeah, a lot like a stack! 03:05:38 heh heh heh heh 03:05:53 tswett: it busy-loops for the minuscule amount of time it takes for the other thread to do two atomic swaps. 03:06:05 umad? 03:06:13 * kallisti mad 03:06:19 * tswett mad. 03:06:40 Yeah, I guess busy looping may be fine if the thread it's waiting on is guaranteed to finish quickly. 03:06:56 Inelegant but fine. 03:07:57 It's probably theoretically impossible to do this with your primitives and no busy waiting 03:08:04 Also, isn't a binary semaphore only two-valued? 03:09:03 A binary semaphore is what we're implementing; that doesn't mean we have to implement it on top of a Boolean variable. 03:09:19 I do wonder if it is theoretically impossible. If it is, I ought to prove it. 03:09:27 * kallisti briefly imagines an "intuitionistic semaphore" 03:18:03 -!- copumpkin has joined. 03:31:49 -!- augur has joined. 03:49:18 -!- lambdabot has joined. 03:52:13 -!- Klisz has quit (Quit: You are now graced with my absence.). 04:05:28 -!- Jafet has quit (Quit: Leaving.). 04:25:29 HI FRIENDS 04:25:39 @hoogle a -> b -> a -> a 04:25:39 Graphics.Rendering.OpenGL.GL.VertexSpec Color3 :: a -> a -> a -> Color3 a 04:25:40 Graphics.Rendering.OpenGL.GL.VertexSpec Normal3 :: a -> a -> a -> Normal3 a 04:25:40 Graphics.Rendering.OpenGL.GL.VertexSpec TexCoord3 :: a -> a -> a -> TexCoord3 a 04:40:08 -!- augur has quit (Remote host closed the connection). 04:46:32 -!- augur has joined. 05:02:09 -!- kallisti has quit (Ping timeout: 260 seconds). 05:03:45 -!- kallisti has joined. 05:03:45 -!- kallisti has quit (Changing host). 05:03:45 -!- kallisti has joined. 05:05:22 -!- Klisz has joined. 05:18:15 -!- sebbu has joined. 05:18:16 -!- sebbu has quit (Changing host). 05:18:16 -!- sebbu has joined. 05:19:08 -!- sebbu2 has quit (Ping timeout: 244 seconds). 05:23:53 awwww yeah 05:24:02 two monitors. so I can watch starcraft II games and get shit done 05:26:08 -!- zzo38 has joined. 05:32:26 -!- Nisstyre has quit (Quit: Leaving). 05:33:12 -!- Nisstyre has joined. 05:51:47 Can there be barrier monad transformer? 06:00:43 I'm not really sure I understand barrier monads 06:01:04 I am trying to do it; maybe this way I trying can work. 06:02:46 -!- oerjan has joined. 06:04:47 oerjan: let D : C^C \to C^C (let's say C_\infty functions only) be the differentiation operator, does it have a unique set of n periodic points of period n for all n? 06:05:18 ugh help English formatting 06:05:26 a unique subspace of dimension n of periodic points of period | n 06:05:28 I'm supposed to format this as like... 06:05:31 name, title 06:05:37 but the title is like... three parts. 06:05:53 Ph.D., Dean, School of Computing and Software Engineering 06:05:55 or something like that. 06:06:09 should I use semicolons? halp 06:06:15 generated by e^(m*2pi*ix/n) for m=0,...,n-1. 06:06:18 do semicolons exist? 06:06:28 zzo38: can you explain a barrier monad? 06:06:36 @tell oklopol see logs 06:06:37 Consider it noted. 06:06:42 Semicolons exist but I don't know what context the document is 06:07:28 maybe like... 06:07:32 oklopol: er, scratch the formula, thinking too fast 06:07:42 Name, Ph.D.; Dean, School of Computing and Software Engineering 06:07:49 but the semicolon looks weird next to that . 06:07:50 drop the 2pi, i think 06:07:57 oh hm 06:08:16 it's e^(phi*x) where phi^n = 1, of course 06:08:25 kallisti: OK. data Barrier f b t = Unit t | Barrier f (b -> Barrier f b t); It means, there is a front type and a back type. The "yield" operation yields a front value and something else make a back value to continue. Similar to how generator functions in JavaScript are, a bit 06:08:25 of which there are n solutions. 06:09:00 zzo38: how does Unit fit into this? 06:09:18 Unit is the "return" operation: return = Unit; 06:09:26 ah okay. 06:10:13 Of course it is also functor and applicative; all monads are supposed to be also functor and applicative. 06:10:25 the case n=4 gives e^x, e^(-x), e^(ix) and e^(-ix), and the last two can be rearranged as (e^(ix)+e^(-ix))/2 and (e^(ix)-e^(-ix))/(2i), which you may recognize. 06:10:31 ah okay, so then the monadic function is the second field there. (b -> Barrier f b t) 06:10:43 @tell oklopol etc. 06:10:43 Consider it noted. 06:11:01 There is actually a third constructor Fail String which is the "fail" operation and is also used for the Alternative instance 06:11:42 -!- copumpkin has quit (Quit: Computer has gone to sleep.). 06:11:55 zzo38: how does >>= work? is there a >>=? 06:12:21 or is there just a f :: Barrier f b t -> Barrier f b t ? 06:12:32 s/f/func/ 06:12:38 (to differentiate it from the front type) 06:12:39 Yes there is a >>= it is: Unit x >>= f = f x; Fail x >>= f = Fail x; Barrier a c >>= f = Barrier a $ c >=> f; 06:12:57 ah okay. 06:13:32 so the front value is... always the same? 06:13:36 at least when binding/\ 06:13:38 and returning./ 06:14:10 kallisti: Do you know the "yield" command in Javascript? The "yield" command here is similar thing (which is the reason why it is called "yield"). 06:14:22 yield = flip Barrier Unit; 06:14:25 So, what's this Barrier thing? 06:14:41 Sgeo: ... 06:14:50 only one question asker allowed. :P 06:14:55 NOT REPEAT QUESTIONS 06:14:58 * kallisti decrees. 06:15:33 Sgeo: See above; I specified the definitions 06:16:12 actually i sent a text to my colleague and he solved it in 2 minutes, ignore that. 06:16:15 TOO LATE 06:17:24 -!- mtve has quit (Ping timeout: 260 seconds). 06:18:26 -!- yorick has quit (Ping timeout: 252 seconds). 06:19:12 -!- yorick has joined. 06:24:58 -!- Klisz has quit (Quit: You are now graced with my absence.). 06:27:11 kallisti: a system which has "truth values" for propositions is usually non-intuitionistic, because intuitionistic logic does not track truth but (constructive) provability. 06:27:59 well, right/ 06:28:14 It could be possible, of course, to model "justified" or "provable" with boolean values, but then it would be quite clear that two values would not suffice. 06:28:19 but it's a sort of truth-valued logic.. 06:28:47 It is possible to make classical logic in Haskell, too, by making a class of law of excluded middle. 06:29:27 if I understand correctly, it's a three-valued logic? or maybe doesn't work like that and exists only as symbolic transformations.. ? 06:29:27 moreover, it's not impossible to prove x || not x if we already know that x is either provable or disprovable 06:29:38 atehwa: yes, I understand that. 06:29:45 i vaguely recall there's a proof that no number of truth values suffices for intuitionistic logic 06:29:54 it may be no finite number 06:29:57 hmm, okay. 06:30:00 interesting. 06:30:17 kallisti: basically, intuitionistic logic is defined by those symbolic transformations 06:30:27 okay, yes I understand now. 06:30:37 what you're trying to do is to give a "semantics" for those symbolic transformations 06:30:52 And I think it can be done by three-valued logic, but I'm not sure 06:30:52 basically implication, though it acts as a symbolic transformation. 06:31:15 oerjan, so, if I were to do it in Haskell, would I require Integer or something, or is it not so straightforward? 06:31:15 Intuitionistic logic is the same as function types of Haskell (due to Curry-Howard). 06:31:18 Or a recursive data type? 06:31:27 Wait what? 06:31:37 well, there's a whole lot of "rules" that describe transformations which are allowed in intuitionistic logic because they're considered "constructive" 06:31:47 Sgeo: zzo38: I was about to say function type is basically implication due to Curry-Howard. 06:31:57 for one thing, intuitionistic logic satisfiability is PSPACE complete, while any finite truth value operators can have it checked in NP. that's not a proof though since it's still not proved that NP /= PSPACE 06:32:03 I don't quite understand Curry-Howard 06:32:28 (p ||q) && not p => q is _not_ one of the allowed transformations, whereas (p => q) && p => q is. 06:33:09 Sgeo: okay so basically types in programs are like mathematical formula, and the program that the type describes is a proof of that formula. 06:33:38 Sgeo: so when you write the type a -> b you're actually talking about a logical implication. 06:34:34 And when I write a -> b? 06:34:41 (I think I saw something about this) 06:34:46 wat? 06:35:10 The fact that there's no way to write a -> b (without cheating) means a -> b cannot be proved, or something? 06:35:22 Sgeo: i guess that you could use kripke models as your representation for intuitionistic logic. i recall playing around with those. 06:35:30 kripke models? 06:35:49 Sgeo: well there's no proof of -> in intuitionistic logic because it's basically the axiom of intuistionistic logic. 06:37:21 http://en.wikipedia.org/wiki/Kripke_semantics#Semantics_of_intuitionistic_logic seems quite unreadable. 06:38:17 Some proofs are simple: doubleNot = flip id; contrapositive = flip (.); deMorgan x = either (fst x) (snd x); 06:38:19 well, the notation anyway. 06:39:16 identity = id 06:39:18 whew. 06:39:22 * kallisti wipes brow. 06:40:08 :t flip (.) 06:40:09 forall a b (f :: * -> *). (Functor f) => f a -> (a -> b) -> f b 06:40:10 Because I'm lazy 06:40:22 ...wrong . 06:40:27 :t flip (Prelude..) 06:40:28 :t flip (Prelude..) 06:40:28 forall b c a. (a -> b) -> (b -> c) -> a -> c 06:40:29 forall b c a. (a -> b) -> (b -> c) -> a -> c 06:40:34 say you want to show that p || not p is not provable in intuitionistic logic, by finding a kripke model in which it's not true in all frames. 06:41:01 In this case, c is Zero (an uninhabited type) 06:41:16 oerjan: what's the type for not in Haskell? 06:41:37 :t flip id 06:41:38 forall a b. a -> (a -> b) -> b 06:41:59 let frame 1 be one in which p is false, and frame 2 be one in which p is true. that satisfies the condition. but then not p is false in frame 1 because p is true in a later frame. and p || not p is false in frame 1 because both p and not p are false there. 06:42:45 -!- Jafet has joined. 06:44:10 ah I see type Not a = a -> b 06:44:26 kallisti: b should be Void 06:44:28 not :: Not a 06:44:31 not = undefined ????? 06:44:32 er 06:44:50 hmmm 06:44:51 oh 06:45:06 Void is the representation of false. 06:45:18 I called the uninhabited type Zero and defined as: data Zero; type Not x = x -> Zero; 06:45:19 or _|_ 06:46:17 hmmm okay, but then what's the proof? 06:46:21 Note you could represent natural numbers by using Zero as number zero and Maybe as successor. If there is such a thing as types that are only capable of holding bijective functions, you could use that to prove equality of natural numbers. 06:46:52 kallisti: proof of what? 06:46:57 oerjan: negation 06:47:03 is it given? 06:47:28 kallisti: to proven negation of x, you construct a contradiction from x. i.e. you construct an element of Not x. 06:47:32 *prove 06:48:08 oerjan: oh okay. so in Haskell data types with constructors are automatically proven, basically. 06:48:33 if they're made of things that are proven (??) 06:48:37 they're automatically proven if you can find the arguments to their constructors... 06:48:46 yes 06:49:02 constructivism wheeeeee 06:49:05 For example: Not Zero proven by the function id 06:49:41 "prove that booleans are true." "okay here you go I made them" 06:49:56 s/are true/exist/ 06:51:06 but not p && p cannot in general be proven (???) <-- it can be disproven. 06:51:46 :t const (const True) 06:51:47 forall b b1. b1 -> b -> Bool 06:51:48 of course with that one in particular, that's a little circular semantically 06:52:12 :t asTypeOf (const True) 06:52:13 forall b. (b -> Bool) -> b -> Bool 06:52:14 @djinn Not (Not p, p) 06:52:14 f (a, b) = a b 06:52:27 explosion :: (p, Not p) -> q; explosion (x, y) = contradiction $ y x; where contradiction :: forall t. Zero -> t; 06:52:34 :t const (asTypeOf True) 06:52:35 forall b. b -> Bool -> Bool 06:52:39 kallisti: @djinn is an intuitionistic prover 06:52:54 @djinn Void 06:52:54 -- f cannot be realized. 06:52:57 @djinn f :: Void 06:52:57 Cannot parse command 06:53:03 @djinn a -> Void 06:53:03 -- f cannot be realized. 06:53:08 is Void not a thing? 06:53:36 Void is an uninhabited type. you cannot actually construct it, it's a representation of a contradiction. 06:53:44 oh... right. 06:53:55 @djinn Void -> a 06:53:56 f = void 06:54:02 @djinn-env 06:54:02 data () = () 06:54:03 data Either a b = Left a | Right b 06:54:03 data Maybe a = Nothing | Just a 06:54:03 data Bool = False | True 06:54:03 data Void 06:54:05 type Not x = x -> Void 06:54:07 class Monad m where return :: a -> m a; (>>=) :: m a -> (a -> m b) -> m b 06:54:08 class Eq a where (==) :: a -> a -> Bool 06:54:29 ah okay, so then Not Void is the only valid type for a in data Not a = Not (a -> Void)? 06:54:30 hm not sure where that void is defined. 06:54:52 kallisti: recursive types are not allowed in this context. 06:54:59 er hm sorry 06:55:00 misread 06:55:42 @djinn Not Void 06:55:42 f a = a 06:55:54 a = Void 06:56:20 @djinn Not Bool 06:56:20 -- f cannot be realized. 06:56:25 ah okay. 06:56:45 * kallisti gets it, I think. 06:58:05 that Bool definition is somewhat unrelated to the intuitionistic truth values 06:58:13 which are Void and Not Void, really 06:58:16 right. 06:58:35 Bool is a sum type of... unit types? 06:59:27 yeah. @djinn's main purpose is to construct haskell functions with prescribed types, so the intuitionistic part is sort of just underlying. 07:01:22 @djinn a -> b -> a 07:01:22 f a _ = a 07:01:58 @djinn Either a b -> (a -> c) -> (b -> c) -> c 07:01:58 f a b c = 07:01:59 case a of 07:01:59 Left d -> b d 07:01:59 Right e -> c e 07:02:32 oerjan: also, are primitive types kind of just... unproven? 07:02:43 like Int#, State#, etc. 07:03:29 @djinn doesn't deal with those, i think. it's not _really_ haskell, but a fragment without nontermination and without recursive types. 07:03:51 ah, well, the Haskell Report does define Int as a huge number of constructors right? 07:03:56 or something like that. 07:04:00 What does Either a b mean in the context of intuitionistic logic? 07:04:04 and you can define new nonrecursive types. 07:04:09 Sgeo: or 07:04:15 a or b 07:04:20 Ah, ok 07:05:14 also the | in data declarations is also or. 07:05:19 Can I read that as "If I have a proof of a or b, and I have a proof of if a then c, and I have a proof of if b then c, then c? 07:05:20 kallisti: well yeah. it's not expected that implementations actually _use_ that representation. :P 07:05:33 Or do I have to do currying? 07:05:38 Sgeo: that's fine 07:06:16 Partial functions don't count as proofs, right? Otherwise I could prove Either a b -> a 07:06:24 indeed not. 07:06:48 What does Maybe a mean? 07:07:02 And how do I do logical and? 07:07:10 Logical and does (,) 07:07:11 and is (,) 07:07:12 it's isomorphic to Either () a 07:07:15 And logical or does Either 07:07:23 *Maybe is 07:07:45 Maybe makes it always true it is always provable by Nothing 07:07:46 oerjan, I take it that that's essentially useless, since it should always be true 07:07:53 Sgeo: yeah 07:07:54 no that's why it's useful. 07:07:59 in program-land :P 07:08:00 For numbers, you might use Maybe for successor, though 07:08:31 @djinn Maybe a 07:08:32 f = Nothing 07:08:43 @djinn a 07:08:44 -- f cannot be realized. 07:09:32 @djinn Bool 07:09:32 f = False 07:10:09 type Bool = Either () () -- yes? 07:10:10 @djinn (() -> a) -> a 07:10:10 f a = a () 07:10:17 kallisti: essentially :P 07:10:31 and () is useless since you can construct it on the fly 07:10:45 oh hm. 07:11:12 Why have anything other than Either, (,), and ()? 07:11:21 And (->) 07:11:25 i _think_ @djinn makes an attempt to use as many arguments as possible, i.e. it's slightly preference for linear logic. so it's not _entirely_ useless. 07:11:37 @djinn Maybe a -> (a -> b) -> Maybe b 07:11:38 f a b = 07:11:38 case a of 07:11:38 Nothing -> Nothing 07:11:38 Just c -> Just (b c) 07:11:58 Since it is isomorphic to Either () a that is why it can be successor, if Either is addition, if you have a type of bijective functions: Either () a <-> Maybe a { Left () -> Nothing; Right x -> Just x; } if you had a <-> type then you could *prove* it to be isomorphic. 07:12:08 Sgeo: that's basically what intuitionistic type theory is. (don't forget Void) 07:12:53 oerjan: It is: f = flip fmap 07:14:04 Why have anything other than Either, (,), and ()? <-- the others are defined using @djinn's definition mechanism 07:14:10 @list djinn 07:14:11 djinn provides: djinn djinn-add djinn-del djinn-env djinn-names djinn-clr djinn-ver 07:14:32 @djinn Void 07:14:33 -- f cannot be realized. 07:14:36 @djinn-add Fnord a b = Fnord a (b -> a) 07:14:37 Cannot parse command 07:14:37 @djinn Blah 07:14:38 Error: Undefined type Blah 07:14:43 @djinn-add data Fnord a b = Fnord a (b -> a) 07:14:45 If you had bijective function type then the types as numbers can be: uninhabited type for zero, Maybe for successor, Either for addition, (,) for multiplication, -> for exponent, <-> with same type on both sides for factorial 07:14:49 @djinn (a -> b) -> Void 07:14:50 -- f cannot be realized. 07:14:53 Oh, come on 07:15:01 @djinn a -> Fnord a b 07:15:02 f a = Fnord a (\ _ -> a) 07:15:14 Fnord? 07:15:21 Sgeo: i just defined it :P 07:15:43 I have no idea what it means 07:15:46 @djinn-names 07:15:47 Either Left Right Maybe Nothing Just Bool False True Void Not Void Monad Eq Bool Fnord Fnord 07:16:01 @djinn Void -> Void 07:16:02 f a = a 07:16:09 there seems to be some duplication there... 07:16:12 @djinn Void -> (a -> b) 07:16:12 f = void 07:16:19 ...huh? 07:16:27 What is void? 07:16:46 It should be: void x = case x of { } but Haskell doesn't accept that 07:16:52 Sgeo: void :: Void -> a 07:16:56 Ah 07:17:09 yeah it may be a special case 07:17:11 So basically, a statement that if you proven void, you can prove anything 07:17:20 yeah 07:18:44 @djinn (Void -> a) -> a -> b 07:18:45 -- f cannot be realized. 07:18:55 In TNT, (exist a. x) is equivalent to (not (forall a. not x)) 07:18:57 Well, that does make sense 07:19:23 @djinn (a -> Void) -> a -> b 07:19:24 f a b = void (a b) 07:19:43 @djinn-del Fnord 07:19:51 @djinn-names 07:19:52 Either Left Right Maybe Nothing Just Bool False True Void Not Void Monad Eq Bool 07:20:04 @djinn Not Void 07:20:04 f a = a 07:20:06 And if you have x{5} or x{anything} then you can make (exist a. x{a}) 07:20:24 Huh? 07:20:51 Sgeo: ? 07:21:18 Is it possible to do this in Haskell? 07:21:39 zzo38: sounds pretty much like dependent typing, so no. 07:22:06 hm maybe on the type level 07:22:29 and who knows with the new type -> kind lifting that's coming up 07:22:34 To be specific, I mean of making (exist a. x{a}) from (x{5}) or whatever 07:22:47 What is type -> kind lifting? 07:24:51 How did it figure out Not Void? 07:25:29 because it's Void -> Void[D 07:25:40 How does Not work 07:25:41 ? 07:26:01 data Not a = Not (a -> Void) 07:26:06 no data 07:26:09 @djinn-env 07:26:10 data () = () 07:26:10 data Either a b = Left a | Right b 07:26:10 data Maybe a = Nothing | Just a 07:26:10 data Bool = False | True 07:26:10 data Void 07:26:12 type Not x = x -> Void 07:26:14 class Monad m where return :: a -> m a; (>>=) :: m a -> (a -> m b) -> m b 07:26:16 class Eq a where (==) :: a -> a -> Bool 07:26:23 ah. 07:26:39 Ah, I'm starting to get an understanding of it now 07:27:05 Does Not need to be a type? 07:27:16 zzo38: http://www.reddit.com/r/haskell/comments/mm68o/ghc_74_branched_whats_in_for_christmas/c328u7i has a small example 07:27:26 well the reply to that 07:27:34 @djinn Either a (Not a) 07:27:35 -- f cannot be realized. 07:27:53 -!- Vorpal has joined. 07:27:56 How would dependent types allow you to make (exist a. x{a}) from (x{5})? GHC does have a existential types extension 07:28:42 zzo38: well it's the part of using the value 5 rather than a type to quantify over, which is problematic. 07:29:01 and which _might_ work with the new extension, i don't know 07:29:12 But I mean for any type in general, not necessarily 5 07:29:18 s/type/value/ 07:29:29 well then i guess ghc can do some of it on the type level. 07:30:16 data Exists x = forall a. Exists (x a) 07:31:36 zzo38: dependent types is when you allow types to depend on values. and ghc does not support it fully, not even with the new extension. 07:32:18 Actually, in the case I given, the 5 *will* be a type, such as (Maybe (Maybe (Maybe (Maybe (Maybe Zero))))) 07:32:40 So it won't depend on a value. 07:33:04 So, it's a bit more that you're doing type-level computation. 07:33:20 well then it should be possible. although there may be further difficulties when you unpack it from the existential again (you cannot compare well things unpacked at different points) 07:33:43 No I mean to prove it by writing functions like how Curry-Howard is 07:41:11 I do have idea of bijective function syntax: A new built-in type "<->" which is like "->" but only bijective functions (a value of this type is allowed to be undefined but can return undefined if and only if the input is undefined), a new keyword "bijective" which introduces layout, and new built-in functions called "inverse" and "runBijective" 07:42:47 inverse :: (a <-> b) -> (b <-> a); runBijective :: (a <-> b) -> a -> b; 07:44:40 The bijective keyword would make a value having a <-> type, and inside would be something similar to a case block (but with some restrictions). 07:45:21 Would this seem to work to you? 07:45:37 i expect finding the right restrictions is the hard part here. 07:48:48 You should also allow bijective functions to be called directly without the use of runBijective (and calling bijective functions directly would be allowed in a bijective case block). I do have some ideas about the restrictions. For example, each variable used on either side must be used exactly once on each side 07:51:19 well my doubt is whether simple restrictions will allow you to write all the bijective functions you want. 07:52:32 Other restriction would be you would be disallowed to write values of recursive types 07:52:40 for example, if f is a halting but otherwise non-bijective function, then g x = x `xor` f x is a bijective function. 07:52:56 er... 07:53:16 *for example, if f is a halting but otherwise non-bijective function, then g (x, y) = (x, y `xor` f x) is a bijective function. 07:54:19 and there are other functions than xor which work that way... any group operation for example. 07:55:13 this is what i thought of when i was pondering reversible computing previously. 07:56:14 You might need to add additional built-in functions 07:57:56 But I don't know if that would make it complete 07:58:18 me neither 07:59:32 I also don't know how you would use it to prove that there is no such bijective function of types (such as: Not (Zero <-> Maybe Zero)) 08:04:38 A proof in intuitionistic or classical logic using Curry-Howard would require all functions written to halt, and that is assumed and the logic still works. Maybe something similar can still work with bijective function type? 08:09:53 linear logic seems somewhat relevant, but not perfectly. 08:10:18 it has the "every argument must be used exactly once" property 08:11:02 but it still allows a function and an argument to combine in a nonreversible way. 08:13:43 I wonder if you could do STM-like stuff without actual repeats (using blocking instead) by using an arrow instead of a monad 08:14:32 That way, all information about what variables may be accessed is known statically, and thus the system can check for conflicting variable access 08:14:47 Before running the thread 08:15:00 hm. 08:15:09 arrows or applicatives, maybe. 08:15:29 Are arrows applicatives? 08:15:41 such prescheduling is supposed to be one of the advantages of arrow/applicative parsers. 08:15:49 Sgeo: technically yes 08:16:07 when you fix the first type argument 08:17:47 http://cdsmith.wordpress.com/2011/07/30/arrow-category-applicative-part-i/ 08:20:31 I need sleep 08:20:34 (btw the answer to the title question is "not quite") 08:20:48 as you need some extras in the other direction. 08:21:25 Could you define applicative in terms of fmap and liftA2 (,) and pure 08:22:37 zzo38: yes. i think that was mentioned in one of the comments to that link. 08:22:48 lax strong monoid something 08:24:14 Can you add something weaker than join or >>= that can still define a monad from an applicative, because join or >>= can be defined from this new thing and the applicative things 08:25:35 -!- monqy has quit (Quit: hello). 08:26:53 -!- GreaseMonkey has quit (Quit: The Other Game). 08:27:42 -!- mtve has joined. 09:15:18 -!- derdon has joined. 09:31:40 -!- oerjan has quit (Quit: leaving). 09:50:49 -!- zzo38 has quit (Remote host closed the connection). 10:05:59 hi 10:49:03 -!- derdon has quit (Remote host closed the connection). 10:54:32 -!- ais523 has joined. 11:57:56 -!- zzo38 has joined. 12:03:22 oerjan: ah, your proof if even nicer than his. 12:03:22 oklopol: You have 2 new messages. '/msg lambdabot @messages' to read them. 12:03:24 *is 12:19:49 The phrase quod erat demonstrandum is a translation into Latin from the Greek ὅπερ ἔδει δεῖξαι (hoper edei deixai; abbreviated as ΟΕΔ). Translating from the Latin into English yields, "what was to be demonstrated"; 12:19:59 that's what all the cool mathematicians say instead. 12:21:34 * Sgeo envisions representing a computable real with a list of tuples, the first number of the tuple being an approximation, and the second being the how far off the approximation is, such that the second number is equal to or larger than the error 12:21:47 Presumably, later values in the list would be better approximations 12:21:54 French people say CQFD 12:22:17 Although I'm pretty sure there's some other infinite list representation of reals somewhere 12:22:29 How do you compute how far off the approximation is from the real value without already having information about the number? 12:23:15 kallisti, the error given in the second number of the tuple may be larger than the actual distance between the approximation and the actual value 12:23:26 I'm presuming there is an actual value, just not easy to represent 12:23:43 I think it makes sense to say that pi is 3 plus or minus .15 12:23:50 For instance 12:24:47 e is kind of like 0 plus or minus infinity. 12:25:02 .. 12:25:37 Most numbers are 12:25:43 Although i isn't 12:25:55 what is a "number"? 12:25:57 If the approximations don't converge, then it doesn't represent an actual number 12:26:11 Can still do comparisons though, in some cases 12:26:59 I should write some code for this 12:29:36 Hey 12:29:38 Sgeo 12:29:43 Hi Slereah 12:29:57 Markov wrote a whole article on writing down definable numbers! 12:30:00 It was neat 12:30:05 Basically, it was like 12:30:22 (f(x) - g(x))/h(x) 12:30:29 Where fgh are recursive functions 12:33:49 Linky? 12:34:04 Although I have a feeling you're referring to a historical source 12:34:07 But still, linky? 12:34:16 Historical indeed 12:34:23 I can give you the reference 12:37:51 Марков, А. А. О конструктивных функциях 12:38:07 Or just Markov, "On Constructive Functions" 12:38:36 I should scan it 12:38:51 No doubt it's already been scanned 12:38:58 Not sure 12:39:02 And sold to universities 12:39:13 http://www.haskell.org/pipermail/haskell-cafe/2011-May/091585.html 12:39:16 I got it from a book that I bought because I could not find an article in it anywhere 12:39:21 infinity = Succ infinity 12:39:31 I find the properties of that fascinating 12:39:44 infinity > any finite natural number 12:39:47 = fix Succ 12:40:05 infinity > infinity = _|_ 12:41:05 data Ordinal = 12:41:08 Hmm, might break on * 12:41:27 Since probably * is defined with Zero on one of the sides as making it = Zero 12:41:34 When the result should probably be _|_ 12:41:48 > 5/0 12:41:49 Infinity 12:41:51 > 5/0 > 6/0 12:41:52 False 12:42:02 Sgeo: IEEE disagrees. :P 12:42:06 > 6/0 > 5/0 12:42:07 False 12:42:27 > 5/0 >= 6/0 12:42:28 True 12:42:31 * kallisti gasps. 12:43:16 But then you break the notion of a == b implying a-b==0 12:43:21 > 6/0 - 5/0 12:43:22 NaN 12:43:45 Oh, no! Extending a field with infinity does not produce a field! 12:43:51 Stop press 12:44:46 :t cycle 12:44:47 forall a. [a] -> [a] 12:45:50 > cycle $ cycle [1,2,3,4,5] 12:45:51 [1,2,3,4,5,1,2,3,4,5,1,2,3,4,5,1,2,3,4,5,1,2,3,4,5,1,2,3,4,5,1,2,3,4,5,1,2,... 12:45:54 Actually, I think 0ω is defined as 0. 12:46:08 > fix cycle [1,2,3,4,5] 12:46:09 Couldn't match expected type `[t1] -> t' 12:46:09 against inferred type `[a]' 12:46:17 So it works out fine, as long as you use unamb. 12:46:21 > fix (cycle.) [1,2,3,4,5] 12:46:22 *Exception: stack overflow 12:46:30 * Sgeo non-arbitrarily decides that a better representation of definable reals is as an infinite list of tuples, but the tuples are a lower and upper bound 12:46:34 Haskell needs to fix this bug. :P 12:46:44 Rather than average and distance 12:46:53 Makes it easier to define sine 12:46:56 etc. 12:47:27 That doesn't really define definability 12:48:02 Are there definable numbers that don't fit the mold? I think I'm fine with some lists that don't represent definable numbers 12:48:04 :t fix (cycle$) 12:48:05 forall a. [a] 12:48:17 > fix (cycle$) 12:48:21 mueval-core: Time limit exceeded 12:48:34 You seem to have described the set of real numbers. 12:50:01 Note: My Haskell library has no intention of making it possible to define undefinable numbers. If you manage to do this with my library, the destruction of the universe is on your hands. 12:52:55 -!- elliott has joined. 12:53:05 elliott: hi 12:53:16 bye 12:53:17 brogerr 12:53:17 elliott: You have 1 new message. '/msg lambdabot @messages' to read it. 12:53:43 ais523 said 15h 26m 2s ago: I didn't delete "why testing is good" and the other one, Keymaker did 12:53:48 ais523: should have protected it! 12:54:00 elliott: protection has no correlation with deletion at all? 12:54:01 in fact, we should just protect all the spam pages... 12:54:11 in fact, nowadays, you can typically even protect a page that doesn't exist 12:54:16 although I'm not sure if Esolang implements that 12:54:31 @tell kallisti something important. 12:54:31 You can tell yourself! 12:54:32 ais523: well, I presume people think twice before deleting a protected page 12:55:37 elliott: not if it was protected because elliott thinks that protecting spam is a good idea 12:55:50 hmm, I wonder if there's a wiki on the Internet whose only purpose is to be edited by spambots 12:55:56 ais523: yes, but you're more reliable than that! :P 12:56:03 and i hope so 12:56:03 and it's just left with registration and anonymous editing open, and left there 12:56:36 the problem is, it'd be basically impossible to find 12:56:37 18:22:35: pikhq_, do you often visit Japan? 12:56:38 18:22:43: Vorpal: No. 12:56:38 18:22:54: Vorpal: In fact, I have never been. 12:56:38 18:23:01: what do you use your Japanese knowledge for then? 12:56:38 world domination 12:56:40 as any sane search engine would sort it to the bottom 12:56:46 ais523: you could advertise it 12:56:49 with spam, even 12:56:50 elliott: Japanese is actually a vaguely useful language to know 12:56:58 then your spambots start editing your own wiki... 12:57:11 I am Wikipedia programmer Brandon Harris. AMA (self.IAmA) 12:57:17 I come across words in languages I don't understand, occasionally 12:57:24 and Japanese is one of those languages 12:57:25 * elliott just stares at that headline for a while. 12:58:50 what's stareworthy about the headline? 12:59:03 elliott: heh 12:59:35 ais523: I have trouble conceiving of Wikipedia programmer Brandon Harris as a real person, he's just that guy in the donation boxes 12:59:38 ais523: like Big Brother 13:00:02 there was no issue for me 13:00:16 in the TV series, Big Brother is a real person too 13:00:19 several, I think, who work in rotation 13:01:33 elliott: Brandon Harris, antagonist to the man. 13:02:04 for twelve years you have been asking, "who is brandon harris?" 13:02:09 this is brandon harris speaking. 13:05:12 "I also work for Wikipedia, and had a rather scary email recently: "Before you edit a banner or update some code, just remember that if our readership was a country it would be the 3rd largest country in the world."" 13:06:29 `log brandon harris 13:07:03 2011-11-28.txt:13:02:04: for twelve years you have been asking, "who is brandon harris?" 13:07:17 `pastelog brandon harris 13:07:28 http://codu.org/projects/hackbot/fshg/index.cgi/raw-file/tip/paste/paste.24786 13:07:54 2011-10-05.txt:19:38:28: "A personal appeal from Wikipedia programmer Brandon Harris." 13:08:41 ais523: haha, wikipedia had to take down the fundraising statistics page because of the traffic from reddit 13:08:59 that sort of thing actually happens occasionally 13:09:20 elliott: I feel like reddit is like this hivemind of horrible internet trend stuff. 13:09:31 it is 13:09:36 when you get up to Admin level, you have to be careful to avoid Wikipedia slashdotting itself 13:09:52 ais523: but how............. 13:09:57 you need to know which bits can handle heavy traffic and which bits can't 13:10:23 (hint: you don't want to hit the toolserver on every page read, or even every edit (more than it's currently hit, that is)) 13:10:37 ais523: hmm, is there only /one/ toolserver? 13:10:39 likewise, you can hit the API on every read, but not really perform more than a few queries 13:10:43 elliott: yes 13:10:51 ais523: "The Wikimedia Toolserver is a collaborative platform providing Unix hosting for various software tools written and used by Wikimedia editors. The service is operated by Wikimedia Deutschland e.V. with assistance from the Wikimedia Foundation. 13:10:51 It consists of thirteen servers as outlined here." 13:10:59 hmm, it looks like one 13:11:01 no it's not, I found the answer before you gave me an incorrect one :P 13:11:02 to users 13:11:12 ais523: so does wikipedia itself :P 13:11:20 so does Facebook. (I think) 13:11:27 (so does everything) 13:11:30 FWIW, there's only one physical server that handles write changes 13:11:34 as in, things that handle the database 13:11:38 the vast majority of them are for reads 13:11:40 https://wiki.toolserver.org/w/images/b/b5/Toolserver-cluster.svg 13:11:51 which makes sense, given Wikipedia's load patterns 13:12:10 ais523: I can't help but feel that Wikipedia could do a lot better than it could if it wasn't tied to its software 13:12:17 (I think they can trivially hot-swap /which/ server handles the writes, though, for redundancy) 13:12:37 yep, MediaWiki is painful 13:12:39 internally 13:12:52 it's excellent in terms of its user-facing behaviour, but behind the scenes it's a mess 13:13:06 there's no need to have a linear history at all, for one thing 13:13:28 "see page as of time X" is a useful operation 13:13:38 ais523: yep, but that's not the same thing 13:13:41 although nonlinear histories can be linearised for that purpose 13:13:55 ais523: I mean, you could easily allow edits to be done on N servers instead of 1 13:13:59 elliott: how do you stalk people with differing viewpoints from your own so you can call them out as deletionists or pushing a POV? 13:14:00 and just merge it afterwards 13:14:09 ais523: although you have to block the confirmation page until the merge happens 13:14:13 so you can notify of conflicts 13:14:27 elliott: well I guess no linear history wouldn't affect the user changes log. 13:14:29 kallisti: with binoculars 13:15:14 I don't think Wikipedia's designed to take Linus' Law into account, either 13:15:22 (note: not actually joking. people do that.) 13:15:26 hmm… MediaWiki's storage model is essentially what git's designed for 13:15:46 kallisti: I've been known to stalk suspected trolls/spammers/vandals before now in order to make sure 13:16:10 and yet it ignores most of the optimisations git's made to handle that 13:16:22 ais523: yes, MediaWiki suffers from being developed before common RCSes 13:16:28 DVCSes, rather 13:16:37 (RCS wouldn't work very well :P) 13:16:38 does SVN use reverse diffs for storage? 13:16:46 dunno anything about SVN's storage 13:17:32 * ais523 frowns at the TDWTF discussion of the twelve weights problem 13:17:43 ais523: mediawiki is only 2 years older than svn, anyway 13:17:52 because it's actually solvable with 13 (at least if you only care about knowing the odd one out, not lighter/heavier), and everyone's missed it so far 13:17:54 sorry, more like one year 13:18:02 so it wasn't really an option at the time, I wouldn't think 13:18:08 elliott: wow, it's hard for me to envisage something revision-control-like being older than SVN 13:18:11 apart from CVS and RCS 13:18:31 ais523: open-source VCS is novel field, really 13:18:38 it only got started around 2001 13:18:45 I mean, anything other than CVS 13:19:34 before VCS closed source developers collaborated via email attachments. 13:19:40 (ha ha ha. but probably true) 13:19:49 ais523: list of VCSes older than SVN: 13:20:10 SCCS (1972) RCS (1982) 13:20:10 PVCS (1985) 13:20:10 CVS (1990) CVSNT (1998) 13:20:12 Software Change Manager (1970s) ClearCase (1992) CMVC (1994) Visual SourceSafe (1994) Perforce (1995) StarTeam (1995) 13:20:16 TeamWare (1990s?) Code Co-op (1997) BitKeeper (1998) 13:20:21 elliott: you can't cure my prejudices with facts! 13:20:41 ais523: no, but I can cause you severe cognitive dissonance! MWAHAHAHAHA 13:21:02 * kallisti 's cognitive dissonance sounds awesome. 13:22:03 gah, my IRC client prints elliott's and kallisti's name in the same color, and I keep reading kallisti's lines as being from elliott and having to do a double-take 13:22:06 even reading the article on cognitive dissonance fills me with anxiety about cognitive dissonance. 13:22:19 also, that line of mine, I typed "color" then spend around 4 seconds wondering whether "colour" would be a better spelling 13:22:20 ais523: this is because we are almost the same person. 13:22:32 ais523: turn off nick colouring, then you just mix people up because of similar names 13:23:40 -!- MSleep has changed nick to MDude. 13:24:01 dude what if we had hair on our palms? 13:24:05 handshakes would be so much weirder. 13:33:33 * ais523 is not entirely convinced that kallisti is not a spambot 13:33:36 just mostly convinced 13:34:08 fungot, can you do handshakes? 13:34:08 Jafet: " who says?" screamed glod. " he was no longer an option. he could hear the sounds of argument coming from the fnord fnord. 13:34:29 ais523: The word douche came to English via French – where today it means shower (from Italian: doccia "conduit pipe" and docciare "pour by drops"). It is thus a notorious false friend encountered by non-native speakers of English. 13:34:53 kallisti: the funny thing is, I actually know its French meaning rather better than its English one 13:39:53 I bet that fizzie is here. 13:41:08 I bet elliott is here. 13:41:15 Wrong! 13:41:17 * kallisti better gambler. 13:43:15 I think elliott would get better odds on his/her bet 13:43:45 I would indeed get better odds on his/her bet. 13:44:40 watg 13:47:16 but my odds are 1 in 1.. 13:47:27 THAT'S ALL THE ODDS 14:01:48 bah, @ has made me unable to be interested in low-level OS news 14:02:29 elliott: oh my god I decided to visit reddit on my own free will what have I done 14:02:39 there's a random button. 14:03:04 there is? 14:03:12 yes you hit random and it /goes to random thingies/ 14:03:14 oh, random subreddit. 14:03:17 boards? uh... 14:03:18 who the hell looks at the top bar 14:03:20 subreddits. 14:03:28 http://www.reddit.com/r/RATS/ rats 14:05:29 http://www.reddit.com/r/somethingimade/ 14:06:52 elliott: show off awesome perl scripts here. 14:06:55 http://www.reddit.com/r/nostalgia/ 14:07:01 elliott: reflect on painful childhood memories. 14:07:05 such as writing perl scripts. 14:08:57 FWIW, there's only one physical server that handles write changes as in, things that handle the database <-- very doubtful that mediawiki wouldn't use a distrubuted database server. Doesn't even mysql support that nowdays? I know postgre supports it well for example. 14:09:11 http://www.reddit.com/r/frugalmalefashion/ 14:09:12 wtf 14:09:44 http://www.reddit.com/r/actuallesbians/ 14:09:47 oh my god it never ends. 14:10:15 http://www.reddit.com/r/Psychonaut/ 14:10:17 I found home. 14:10:23 In the "X is a monad" series: 14:10:34 where's /r/fakelesbians 14:10:36 A certain way of writing BF programs is a monad (I think) 14:10:53 Sgeo: what 14:11:08 * itidus21 laughs 14:11:15 Vorpal: maybe ais523 means "one hostname" like he did with the toolservers:P 14:11:16 State representing locations of variables 14:11:52 Run the monad, which must return something of a certain type, and you get a BF program 14:11:54 elliott: ah help kallisti is always taken how do I make usernames? 14:11:55 Anyways, bye 14:12:21 kallisti: kakeprophet 14:12:28 noooo 14:12:32 cakeprophet is better 14:12:40 I need 14:12:42 ORIGINAL THOUGHT 14:12:43 kallisti: if you do sign up to reddit, i suggest the first thing you do is to unsubscribe from all default subreddits 14:12:46 THAT IS NOT LAME. 14:12:50 elliott: obviously 14:12:55 at least /r/{pics,funny,politics} 14:12:59 oh /r/WTF too 14:13:09 politics might be good 14:13:14 kallisti: /r/politics is actually US politics (is actually US politics circlejerk) 14:13:17 but maybe there are better news sources. 14:13:23 elliott: that's fine I like that . 14:13:29 no you really don't 14:13:33 oh. okay. 14:13:38 elliott, anyway you still need to propagate writes in a consistent order, even with a distrubuted db. At least if you want a consistent history for edits like mediawiki does 14:14:33 hm an obvious solution to load balancing here would be to hash the article identifier and use that to select which database server to use. Don't even need distributed databases for it 14:14:36 Vorpal: only a few things need consistent ordering in MW 14:14:37 Also /r/{atheism,gaming} and maybe /r/{IAmA,todayilearned} and /r/AskReddit 14:14:49 /r/atheism isn't default these days 14:14:51 Nor is gaming 14:15:02 atheism? default? whut. 14:15:03 * elliott checks the default list 14:15:04 They appeared to be, I just logged out to check 14:15:11 Oh, gaming and atheism are 14:15:51 elliott: it's like they want /r/atheism to be full of controversy 14:15:53 kallisti: OK, here's an unsubscribe list: /r/{pics,funny,atheism,politics,WTF,AskReddit,AdviceAnimals} and most likely /r/{gaming,todayilearned} 14:15:54 by putting everyone in it. 14:16:21 You definitely want out of /r/gaming, there are better replacements 14:16:29 Deewiant: Yeah, I'm not subscribed so I didn't feel qualified to say 14:16:29 such as? 14:16:39 kallisti: No, it's not full of controversy at all, /r/atheism is actually the internet's largest circlejerk 14:16:51 /r/{Games,gamernews,truegaming} 14:17:02 truegaming sounds good maybe? 14:17:04 Depending on what you want, you can pick (I'm subbed to all three) 14:17:08 or maybe it's falsegaming acting like truegaming 14:17:08 truegaming is only for discussions 14:17:08 kallisti: Okay, what Deewiant said, except don't subscribe to anything starting with "true" 14:17:18 but true sounds all elitist. 14:17:19 -!- Madoka-Kaname has quit (Remote host closed the connection). 14:17:21 * kallisti elite 14:17:27 Of true* I'm only in TrueReddit and truegaming 14:17:32 I find they have interesting content 14:17:40 -!- Madoka-Kaname has joined. 14:17:49 Deewiant: Maybe, I just can't stand the implicit elitism :P 14:17:58 http://www.reddit.com/r/TrueTrueReddit 14:17:59 so my brother has skyrim.. watching him play it makes my life feel painfully inadequate. 14:18:01 I'm in it for the links, not the comments :-P 14:18:02 This is actually a real non-joke subreddit. 14:18:10 http://www.reddit.com/r/content/ omg so much content 14:18:11 "As TrueReddit grows, it will become less like TrueReddit. See "Hot Tubbing an Online Community" for thoughts as to why. By virtue of the fact that it is smaller, and will not yet make /r/all, TrueTrueReddit is better equipped to adhere to its own standards." 14:18:12 Oh, it's non-joke these days 14:18:12 itidus21, why don't play it yourself too? 14:18:15 TrueTrueReddit used to be a joke 14:18:20 TruestReddit 14:18:32 Vorpal: do you want the real answer? 14:18:35 itidus21: I don't understand the hype around Skyrim actually. 14:18:38 though it is a good game. 14:18:41 itidus21, why do you ask? 14:18:56 kallisti: it looks like so much freaking fun thouhg 14:18:58 kallisti: Oh, and don't subscribe to /r/programming, though it isn't default 14:18:59 kallisti, not a good game. A fun game sure, but too buggy to be a good game 14:19:05 elliott: well, duh. 14:19:13 elliott: that would be like going to the programming board on 4chan. 14:19:16 /r/AskReddit can be moderately interesting for some things but I think it's best to just take a quick look at the topics once a week or so than have it on your frontpage all the time 14:19:19 kallisti: /r/coding is... "okay", but /r/haskell is the only decent programming subreddit I know of 14:19:22 At least, that I care about 14:19:28 kallisti, somehow after I saved a game I got a non-random quest a second time. 14:19:31 Actually it's one of the only reasons I use reddit still :P 14:19:32 elliott: I am an expert at internetz brah, I've got this. 14:19:33 that annoyed me 14:19:34 elliott: You know that /r/programming is better these days, right? 14:19:47 Deewiant: I read it every day; it really isn't 14:19:52 I think it is 14:19:57 Vorpal: certainly less buggy than previous Bethesda games 14:20:08 Deewiant: OK, the links are usually interesting, but then I check the comments and everything goes downhill 14:20:12 Vorpal: or well, many many many games that people have flooded money into. 14:20:14 Deewiant: Especially if it involves Haskell :) 14:20:25 elliott: The solution to this for you is: don't check the comments 14:20:31 kallisti, well maybe on release. I didn't play oblivion until some fairly late patch 14:20:34 elliott: (For others, it's also "don't care about the comments" but I doubt that works for you) 14:20:34 Deewiant: I can't stop myself 14:20:41 Vorpal: perpetuating a vile industry that encourages rapid deadlines and not good finished products. 14:20:53 VILE 14:20:55 VILE I SAY 14:20:58 heh 14:21:00 yes, evil 14:21:03 like vile 14:21:06 what is deadlines about? 14:21:06 elliott: I wonder if RES or something allows for removing the comment links :-P 14:21:07 but with shit switched around. 14:21:16 Deewiant: I tried RES once and I just got annoyed at all the visual noise :P 14:21:29 elliott: Just configure it, you can remove everything you don't want 14:21:36 Yeah I know, I just also don't have any use for it 14:21:43 i mean, if deadlines are such a problem why are they so important 14:21:54 I use it mostly for its "hide child comments" feature 14:21:56 http://www.reddit.com/r/shrooms/ I am disappointed at the lack of quality post things. 14:22:04 itidus21: What's the real answer, since Vorpal is too boring to ask 14:22:07 kallisti, anyway, I seen quite a few stable games on their release. None of them were open world sandbox games though. 14:22:28 elliott: as with most things it is best understood in a functional sense 14:22:34 /r/starcraft yesssss 14:22:34 :) 14:22:45 /r/starcraft is kind of shitty as well 14:22:47 I think they have an IRC channel as well? 14:23:09 As an anthropologist studying the primitive /r/starcraft natives, I can confirm that it's shitty 14:23:12 It's more about the people than the game 14:23:17 Also they're weird 14:23:24 elliott: but maybe it has like... starcraft games? 14:23:25 and stuff? 14:23:35 elliott: so.. the core explanation is i don't have either 1) the game 2) a PC which could play the game. 14:23:44 itidus21: Riveting 14:23:49 elliott: I bet they use a lot of jargon you don't understand. 14:24:00 For me /r/starcraft is like /r/AskReddit, I check it on occasion but don't subscribe to it or read it actively 14:24:01 but it gets more complex 14:24:06 elliott, my only experience of starcraft is watching a few minutes of a commentated match. It was mostly incomprehensible jargon. 14:24:26 Vorpal: the jargon is actually not that dense. 14:24:28 Surprise: thing you know nothing about is incomprehensible 14:24:36 Deewiant: I don't know why you'd check /r/AskReddit ever, anything actually decent filters through to /r/bestof or whatever (which is admittedly kinda awful itself), and the rest is really awfully inane stuff 14:24:43 I don't read /r/bestof 14:24:45 kallisti, just as dense as for dota/lol/hon. 14:24:46 FoxTrot creator Bill Amend is thinking about doing StarCraft 2 commentaries. Let's encourage him! (twitter.com) 14:24:46 What. 14:24:52 which is also mostly incomprehensible 14:24:52 Deewiant: /r/bestof is default these days :P 14:24:58 Deewiant: http://blog.reddit.com/2011/10/saying-goodbye-to-old-friend-and.html has the current list 14:25:04 elliott: I unsubscribed from it long before it was default :-P 14:25:05 elliott: 6pool, 3rax, 3gate, 1-1-1, etc 14:25:13 1) i don't have a job. 2) i don't have any money 3) i don't have any income. 4) whatever money i got in the last year from gifts such as xmas or birthday or other ended up going to my mom 14:25:15 kallisti: Nope, haven't seen anything like that 14:25:24 kallisti: I think you're expecting too much of them, it seems to mostly be celebrity worship crap 14:25:28 4b) she ended up wasting most of this buying me soft drink and junkfood 14:25:28 ..oh 14:25:30 dumb. 14:25:37 I was expecting like... people who play starcraft 14:25:39 and know things about it. 14:26:41 1) my brother has an explosive anger problem 2) my brother is greedy and selfish for some reason 3) due to (1) and (2) whenever i might acquire anything my brother wants he will just take it rather than waste energy getting his own copy of said thing 14:27:14 when i was about 10, i learned that in my house if i wanted to make a glass of cordial i basically had to pour one for everyone 14:27:18 itidus21, you forgot 2i) There are other ways to get hold of games if you want to. 14:27:20 elliott: As for /r/AskReddit, there's a good question once in a while plus I find reading about amusing real-world stories a significant improvement to e.g. /r/{funny,pics,videos}; it works with RES's "hide all child comments" well, too, so you can only read the top-level replies 14:27:27 itidus21: http://www.reddit.com/r/drugs/ 14:27:51 im trying to express i guess how futile my life is.. 14:28:01 http://i.imgur.com/MvQ9G.jpg 14:28:03 itidus21, unless you use a console rather than a PC for gaming, in which case why on earth? 14:28:05 I'm trying to figure out 14:28:10 what this picture is trying to express 14:28:15 an unrelated problem altogether. 14:28:32 itidus21: this is perhaps the most elaborate learned helplessness ever conveyed over irc 14:28:51 itidus21, just use torrents? *shrug* 14:28:53 Deewiant: "hide all child comments" sounds nice in theory but makes me miss out on e.g. when a high voted comment has an even higher-voted reply proving it's bullshit :P 14:29:08 Vorpal: my pc isn't near good enough to run it 14:29:09 elliott: You can always manually check the replies 14:29:22 well i am not sure how good my pc is though but yeah 14:29:22 elliott: we're all in a state of learned helplessness man. 14:29:23 elliott: (There's a "show child comments" button after hiding) 14:29:34 elliott: what are you gonna do about pollution, dawg? 14:29:36 nothin' 14:29:36 not shit. 14:29:39 elliott: And that's what I usually do when I come across something that might need proving :-P 14:29:48 elliott: But it hides pun threads and such effectively. 14:29:55 Deewiant: Maan, I don't read reddit to think 14:30:02 But yeah, anything that gets rid of pun threads is tempting :P 14:30:15 itidus21, well then I guess you are stuck. Gaming when there are ranged weapons (bows and spells here) on consoles is generally horrible anyway due to lack of any sort of precision in aiming without a mouse. 14:30:17 wow a lot of pill-poppers on /r/drugs 14:30:20 lame. 14:30:58 uh oh, Vorpal is one of those "I can't aim with a thumbstick" people. 14:31:08 Vorpal: im just saying i feel how deprived i am when watching my brother play skyrim on a pc 14:31:19 kallisti, I consider "auto aim" to be cheating. I know a lot of shooters on consoles use them. 14:31:25 But that shouldn't be needed 14:31:27 Vorpal: that's not what I'm talking about. 14:31:29 it's not needed 14:31:40 you can do this neat thing where you turn up the sensitivity on the aiming 14:31:42 and ... i feel how fucked my life is on every level.. 14:31:46 kallisti, it takes much more time to aim with a thumbstick than with a mouse 14:31:53 and it gives you like, control over where you aim things based on how far you tilt the thumbstick 14:31:56 it's pretty neat. 14:32:18 Vorpal: s/$/ for me/ 14:32:22 Vorpal: s/$/ because i'm bad at it/ 14:32:25 i keep myself happy by lying to myself 14:32:28 sweet lies 14:32:41 kallisti, still inferior to a mouse. 14:33:04 kallisti, anyway another problem: current consoles are way behind PCs when it comes to graphical fidelity. 14:33:19 ~graphical fidelity~ 14:33:24 lol 14:33:31 graphical quality then. Whatever you call it 14:33:45 elliott: i have learned that a nation has a similar problem when it feels its borders are too small.. and it has to ask all its neighbors to compromise 14:34:05 like suppose italy wanted to expand itself.. then all of europe might have to shift their borders 14:34:57 i have also learned that revolution tends to lead to a lot of deaths, and that border-renegotiations tends to lead to war 14:35:30 kallisti, just compare a high end PC with the current PS3 or xbox 360 (wii is even further behind it seems). Assuming they all render to the same resolution, which system will be able to provide the best graphics? The PC. 14:35:32 and i know that, inspite all this a majority of the population of the world are screwed 14:36:26 Vorpal: nobody actually gives a shit though because nobody derives fun from standing in front of a texture and admiring how high-resolution it is. 14:36:30 its like helplessness might be part of the system.. like... why are creatuers with learned helplessness surviving natural selection 14:36:43 Vorpal: and consoles are attached to televisions which you sit further away from to play and therefore notice finer details less. 14:37:23 elliott, the second point is true yes. 14:37:25 itidus21: because we don't actually have to fight for our lives/ 14:37:31 itidus21: we've won the game. 14:37:35 collectively 14:37:40 yay 14:37:45 in... this country anyway 14:37:50 and many others. 14:37:50 I prefer games to cover a larger part of my field of view though. 14:38:56 elliott, but you yourself complained about the texture quality in skyrim screenshots. So you obviously do think it matter to some degree. 14:39:01 matters* 14:40:12 one of the cool things about it is so much voice acting in it.. and so much stuff in it.. and the conversation trees (seem a bit contrived at times, but oh well) 14:40:58 its not hte game itself i guess, but realizing that i'm not at that level of society that can play a modern pc game 14:41:00 elliott: oh snaaaapp 14:41:05 its not like owning a car 14:41:14 its merely a pc.. 14:41:18 but.. 14:41:20 >_> 14:41:34 its more than i can fit into my life 14:41:38 dude who needs a car. 14:41:39 just like 14:41:45 order groceries online, do freelance work. 14:42:14 take the bus 14:42:16 or train 14:42:21 Vorpal: ha 14:42:22 clearly if i cannot buy myself a new pc ... a car is not in wildest dreams (even though diabetes is main reason i shouldn't drive.. and problems i suspect in my vestibular system) 14:42:32 kallisti, well if you are in US you are screwed 14:42:48 and.. you can rule out a girlfriend 14:42:55 hm? 14:43:01 but thats kind of implied by the whole geek thing :P 14:43:15 not really. 14:43:54 maybe you're just caring about the wrong things, and letting completely irrational beliefs hold you back. hmmmm? 14:44:28 at this rate, before i die i will face a living hell on earth 14:44:43 as the problems i am describing escalate and close in on me 14:44:48 anyway there are compsci students that are female. Far fewer than half of the students, but they do exist at the university I'm studying at least. 14:45:05 Vorpal: yes I even saw one in one of my classes! 14:45:06 of course 14:45:21 i never planned for the possibility my brother would turn on me 14:45:32 kallisti, I think it is something like two out of 18 in one of the current courses I'm taking. 14:45:43 courses I'm currently taking* 14:45:49 she was even attractive! but, that's no place to pick up women, since... everyone is basically fawning her. 14:46:08 and she was probably like married or something 14:46:26 heh 14:46:52 -!- ais523_ has joined. 14:46:57 -!- nooga has joined. 14:47:10 kallisti, not so much of that here. I usually hang around with a group of around 5 people for stuff like lunch and so on, one of them is in that group. Just plain friends. 14:47:28 so, question I'm asking my students in this marking session: they have to write (in Java) a recursive method that sums a linked list 14:47:32 hi ais523_, run away 14:47:44 and I'm asking them what would happen if they removed the base case 14:47:52 the answers are interesting, sometims 14:47:52 ais523_, speaking of which, does java optimise tail recursion? 14:47:53 *sometimes 14:48:04 Vorpal: I don't know; I think it's allowed to, but generally doesn't in debug mode 14:48:08 but I'm not sure 14:48:09 ah 14:48:42 ais523_, so what sort of interesting answers were there? 14:48:43 linked list, in java, what for? how? 14:48:53 nooga: same way you define a linked list in C 14:48:58 nooga, it is trivial to do with classes? 14:49:11 nooga, since everything but the primitive types are by reference 14:49:22 at least as far as I know 14:49:22 or, fwiw, java.util.LinkedList 14:49:52 but there are no pointers in java 14:49:58 yes there are 14:50:00 everything's a pointer 14:50:04 no need to roll your own when perfectly reasonable doubly-linked lists exist 14:50:11 nooga: Java has references, which are a special case of pointers 14:50:19 nooga, everything except primitive types are references. 14:50:24 (or to look at it another way, pointers are a common way to implement references) 14:50:28 and references are enough for a linked list 14:50:34 oh, okay 14:51:13 I come from a world of pointers 14:51:18 ais523_, so what sort of interesting answers were there? 14:51:23 Vorpal: well, the students who are trying to answer everything by rote assume they'd get a stack overflow, because that's always what happens when you remove the base case of a recursion, right? 14:51:34 so I ask them what'd happen when the end of the list is reached 14:51:35 ais523_, heh 14:51:37 nooga: ruby - world of pointers 14:51:41 funniest answer so far is that it goes back to the start of the list 14:51:57 Yes, java.util.LinkedList, the linked list that lacks an easy of way of retrieving the tail 14:51:57 ais523_, non-ciruclar list I take it? 14:52:01 circular* 14:52:08 Vorpal: singly linked 14:52:19 it's handrolled, and does have an accessor for the tail 14:52:20 ais523_, you can have a singly linked circular list! 14:52:27 but sure 14:52:34 elliott: well, ruby is not my main language ;p 14:52:46 also, it doesn't have a constructor or setter method that would allow creating a circular one without bypassing the security model somehow 14:52:55 Deewiant: Seriously? 14:53:01 * kallisti hasn't figured out his "main language" 14:53:06 I don't think I have one of those. 14:53:13 elliott: seriously; you can mutate it into its tail 14:53:15 ais523_, how can someone fail a simple question like that, I don't get it. 14:53:20 elliott: It's the reason I rolled my own at one time 14:53:23 but not get a reference to the tail without changing it 14:53:38 Oh, right, it's "linked list: the arraylist interface" 14:53:46 AKA the least useful structure, ever 14:53:55 wait 14:53:56 You can do subList(1, list.size()) but that probably copies n-1 elements 14:54:00 btw, about tail-calls in Java, I just looked it up; the JVM doesn't do it because it needs to maintain the stack trace as expected 14:54:13 ais523_, ouch 14:54:15 You can do tail calls with stack traces trivially 14:54:17 but individual JVM languages can optimise tail-recursion (i.e. self-tail-calls) into loops if they want 14:54:20 But that's GvR's excuse too 14:54:29 I thought you don't give a shit about Java and now, suddenly, everybody is talking about Java 14:54:32 how come 14:54:37 because ais523_ brought java up 14:54:40 because ais523_ teaches java 14:54:42 ais523_, is javac able to do that? 14:54:43 "Trivially" is a bit much; simply, maybe :-P 14:54:45 you can get the names of functions trivially 14:54:48 because we talk about the things ais523_ talks about 14:54:50 elliott: you can't inspect the values of params back along the stack, though 14:55:08 ais523_: excuse me, but... begone! 14:55:09 elliott: because I'm marking Java right now, except it's a two-week exercise and the student in this slot did it all last week 14:55:09 :] 14:55:09 ais523_: Sure you can, it just means you leak memory 14:55:12 to get the week off this week 14:55:20 Admittedly, that's almost the same as not optimising tail calls 14:55:22 elliott: wait, is that even a tail-call any more? 14:55:33 the obvious place to store it is the call stack 14:55:41 Store it somewhere bigger 14:55:47 I suppose it'd be a tail-jump; when you actually hit the return of the tail-calls, just pop all the stack elements at once 14:55:57 so you get a speed improvement if not a space improvement 14:56:06 * elliott thinks the tail call argument is rubbish anyway 14:56:09 * ais523_ realises with horror that this is actually a standard idiom in INTERCAL 14:56:12 people just make it up when trying to think of excuses not to implement it 14:56:18 the jvm should have a flag to loop tail recursion and not give a damn about stack data :/ 14:56:33 tail-jumping, that is 14:56:35 I have never heard of anyone failing to debug a Scheme program because they tail-recursed and the stack trace didn't have all the frames 14:57:15 elliott: the typical API to a Prolog debugger (which seems standard among multiple implementations, strangely) tends to have two different operation modes, one which tail-recurses and one which doesn't 14:57:24 I'm not sure if it extends to tail-calls generally 14:57:29 prolog is weird though 14:57:43 also anyone who does tail recursion optimisation as opposed to tail call optimisation 14:57:46 is not my friend, advanced warning 14:58:02 when not debugging, it optimises out the tail-recursions just fine (again, not sure about general tail calls); in the debugger, I imagine being able to see them helps sometimes 14:58:17 meanwhile, Perl has specific syntax for doing a tail-call, and probably doesn't do them if you don't use it 14:58:20 anyway you could just do the optimisation at compile-to-bytecode time. So there is really no obvious reason to not have it there rather than in the jvm 14:58:25 which is an interesting middle ground 14:58:28 unless you can JIT better doing it in the JVM I guess. 14:58:29 didnt prolog come before haskell? 14:58:33 Vorpal: I think the JVM has a concept of methods 14:58:42 quintopia: I'm not sure, they're both earlier-than-you'd-think 14:58:46 and I'm not sure which is more earlier 14:58:47 ah 14:59:38 ais523_, probably. Still there is no obvious reason to not optimise tail calls already in the compiler if the end result (the machine code produced by the JIT) ends up equally good to doing the whole thing in the JIT would have. 14:59:43 gah the grammar of that. 15:00:00 hm 15:00:12 http://blogs.oracle.com/jrose/entry/tail_calls_in_the_vm 15:00:12 prolog predates haskell by over two decades :O 15:00:16 never really thought about TCO before 15:00:23 (proposal to add tail-calls to Java bytecode in a backwards-compatible way) 15:00:48 -!- elliott_ has joined. 15:01:04 didnt prolog come before haskell? 15:01:11 prolog 1972 15:01:24 haskell 1987-1990 15:01:31 wow, Prolog's as old as INTERCAL 15:01:35 * elliott_ doesn't think haskell is "earlier than you'd think", personally 15:01:46 < quintopia> prolog predates haskell by over two decades :O 15:01:49 * elliott_ is surprised that Prolog is that old though 15:01:55 I would have guessed... 1983? 15:02:20 ISO Prolog is 1995, though. 15:02:49 i suspect the syntax that haskell and prolog have in common was extant before 1995 15:02:52 in prolog 15:03:05 that's 15:03:09 not much syntax at all 15:03:14 in fact, I'm having a hard time of thinking of a single piece 15:03:22 well, not exact syntax 15:03:58 but the idea of multiple alternate subcases of a fact/function being built into a syntactical structure 15:04:13 -!- elliott has quit (Ping timeout: 245 seconds). 15:04:25 huh? 15:04:48 its not something languages had before prolog that i can tell 15:05:09 do you just mean writing pattern-matching like 15:05:13 f ... = ... 15:05:14 f ... = ... 15:05:16 rather than like 15:05:18 f x = case x of ... 15:05:27 and not being able to define multiple top-level clauses for "f"? 15:05:35 yeah i guess 15:05:47 otherwise i dunno what you mean 15:05:56 of the idea of patternmatching defs in general 15:06:26 anyways shower time. i'm already running way late. 15:07:19 for shower? 15:08:32 -!- ais523_ has quit (Ping timeout: 265 seconds). 15:13:34 -!- ais523_ has joined. 15:13:54 back 15:14:12 and that was a weird pingout, pinging out from the webclient while on a desktop computer with a wired connection 15:15:05 the way patternmatching defs work in Prolog is entirely different from the way they work in Haskell, though 15:15:14 as in, they do the same thing, but for entirely different reasons 15:16:05 hmm, is it possible to create a reversible language where only the program /state/ needs to be known to compute the previous one, not the state _and_ the program? 15:16:12 I realise that's a kind of vague concept 15:16:23 reversible CAs do that, except they embed the program into the state already, kind of :P 15:18:25 -!- zzo38 has quit (Remote host closed the connection). 15:23:18 ais523_: oh, my name is johny, what the F**K? seems to be forming properly in my head 15:23:29 by which I mean, I'm coming up with a language and it seems good enough to give it the name 15:27:47 yay 15:27:53 capital J on Johny, right? 15:27:55 -!- copumpkin has joined. 15:28:06 ais523_: probably 15:28:16 I can check, if necessary 15:28:41 -!- ais523_ has quit (Quit: Page closed). 15:30:31 the ** in the name of that language, I mentally pronounce as somewhere between öö and üü 15:30:35 but a bit shorter 15:33:48 hmm, the problem with having reversibility based on state alone is that no two different programs can produce the same state 15:34:03 seems like I'm edging close to Rice's theorem if I'm not careful 15:38:39 which one is Rice's theorem? 15:39:04 http://en.wikipedia.org/wiki/Rice's_theorem 15:39:16 in this context, the problem is basically that you can't compute equality for functions 15:40:17 oh right, that one 15:41:53 incidentally, a few days ago, there was a Haskell fan flaming OCaml for accepting = on functions (and throwing an exception if you tried to use it) 15:42:03 also, for defining < and > on absolutely everything that has an =, even if it's arbitrary 15:42:15 (that is, they're consistent with =, but otherwise arbitrary, in some cases) 15:44:39 ais523: where? (and I agree) 15:44:47 although, that thing is a bit hypocritical 15:44:55 Haskell has arbitrary Ord instances too 15:45:04 beacuse our structures like to use them 15:45:09 elliott_: in real life 15:45:38 in real life my structures are giant monsters that eat me. 15:45:41 one advantage of working in a CS department is that you have a nontrivial chance of encountering a Haskell fan 15:45:59 elliott_: remember the Bjorn stories? kallisti reminds me of that, just less extreme 15:46:10 lol 15:46:23 what are those? 15:46:41 `log Bjorn 15:46:47 2011-09-13.txt:18:09:15: `log Bjorn 15:46:52 that wasn't useful… 15:46:54 `log Bjorn 15:47:04 2010-07-24.txt:03:54:13: The merchant tottered away uneasily, and decided to get a job that involved fewer crazy people. Say, telemarketing. Bjorn voyaged on through the dark for maybe three meters before giving up and resting for the night. 15:47:07 past elliott: stop being curious 15:47:14 there we go, it's that sort of thing 15:47:26 `log Bjorn 15:47:31 2011-09-13.txt:18:07:47: oh, I forgot all about the Bjorn thing 15:47:35 `log Bjorn 15:47:41 2010-07-24.txt:03:52:04: As Bjorn woke the next morning, he was, much to his chagrin, reminded of his exploits-to-be by his least favourite region of the brain, which was whatever part stored memories; Bjorn wasn't really sure how the brain operated, apart from that he wished it wouldn't do so in such an efficient and unforgetting manner. So he trundled off again to the pub, and finally got up the energy, 15:47:51 that alise was a weird person 15:47:54 -!- copumpkin has quit (Remote host closed the connection). 15:48:18 -!- copumpkin has joined. 15:49:03 alise was better at Bjorn stories than the rest of us 15:49:24 Sgeo: updersation between itidus21, Vorpal, and kallisdeet 15:49:30 Bjorn, sadly, was better at Bjorn stories than himself, but he wished it was worse 15:49:35 (continuing with the fractal theme) 15:50:07 ais523: hmm, I think I know how to implement addition in My name is Johny, what the F**K? branch 2, but I'm not sure about multiplication 15:50:20 that's always a good sign 15:50:45 ais523: but if what I have is a correct implementation of multiplication, I fear that the language may be fairly boring 15:51:06 is it obvious? 15:51:17 if it's correct but non-obvious given esolang knowledge, you've probably found something new 15:51:24 is what obvious? 15:51:29 the multiplication impl 15:52:30 ais523: I think so 15:52:37 hmm, ah, I think I know what I need 15:52:50 unfortunately, I'm not sure how to make it /mandatory/ 15:52:56 if it's not, you can write programs easily but boringly 15:55:05 -!- Phantom_Hoover has joined. 15:55:23 ais523: 15:55:23 fact(Z) = (S(Z), Z); 15:55:23 fact(S(n)) = 15:55:23 let (r, j) = fact(n); 15:55:23 (r', j') = times(S(n), r) 15:55:23 in discard j' = r; 15:55:25 r = fact(S(j)) 15:55:27 in (r', S(j)); 15:55:52 elliott_: is that MNIJWTF? 15:55:59 ais523: branch 2 branch 1 15:56:34 gah, it looks vaguely like Haskell but trying to interpret it as Haskell makes my head spin 15:56:40 that's also a good sign :) 15:56:56 ais523: try ignoring discard...in 15:57:06 and note that times returns a tuple 15:57:08 nah, I think I know what discard does 15:57:18 it asserts that both values are equal, and then forgets about them 15:57:24 and forgetting about data is otherwise impossible 15:57:25 it only forgets about the LHS 15:57:30 err, right 15:57:32 right 15:57:34 ofc 15:58:04 ais523: the problem is mainly, how do I force people to use discard? rather than just doing something like 15:58:12 fact(Z) = (S(Z), Z); 15:58:12 fact(S(n)) = 15:58:12 let (r, j) = fact(n); 15:58:12 (r', j') = times(S(n), r) 15:58:12 in (r', (r, j', S(j))); 15:58:24 where you basically just thread computations and put all the junk in one value 15:58:40 what about making the language typed? 15:58:46 elliott_: the value is thusly called "the trunk" 15:58:47 (as in, typed lambda calculus)? 15:58:49 ha. ha. 15:59:25 ais523: ooh, that might actually work 15:59:39 ais523: except, ah, no 15:59:49 then you have to invent a monstrously complicated ADT to lump all the junk in one value 16:00:04 err, not ADT 16:00:09 fact(Z) = (S(Z), [Z]); 16:00:09 fact(S(n)) = 16:00:09 let (r, j:js) = fact(n); 16:00:09 (r', j') = times(S(n), r) 16:00:09 in (r', S(j) : r : j' : js); 16:00:12 recursive type 16:00:12 hereafter called "the trunk" plz 16:00:22 ais523: maybe if it was the simply typed lambda calculus 16:00:23 kallisti: but we're trying to get rid of it 16:00:27 ais523: but the STLC can barely /compute/ anything 16:00:32 I'd like this to be TC 16:00:39 ais523: okay then plz name your finished solution "the trunk" 16:00:40 elliott_: what's the difference? no recursive types? 16:01:06 kallisti: elliott_ and I both care deeply about MNIJWTF, we want a truly great language to represent the name 16:01:08 ais523: STLC just has Q and (A -> B) as types 16:01:11 where Q just means "anything" 16:01:28 elliott_: crazy idea: what about bounding memory usage somehow? 16:01:44 although that gets rid of TCness, it still allows the vast majority of practical programs 16:01:54 apart from interps and similar constructs that absolutely need to be TC 16:02:09 hmm, that reminds me, I still need to invent ACK 16:02:23 the esoteric programming language that is not TC, but only barel 16:02:25 *barely 16:03:14 ais523: hmmm, maybe 16:03:47 ais523: what if i made it bounded but infinite? 16:03:48 (the idea is, there are two sorts of entropy; there's minor entropy and major entropy, all operations cost minor entropy, major entropy allows you to ackermann-function your minor entropy but you only have a finite, program-specified, amount) 16:03:52 hey guys we're on topic. 16:03:53 amazing. 16:04:02 kallisti: stop trying to derail us, this channel is even better ontopic than offtopic 16:04:09 I'm... not? 16:04:39 * kallisti was actually just discussing (read: ranting to himself with a witness) an esolang. 16:04:40 ais523: that is to say, like, you have aleph_null ram 16:04:59 ais523: but if you do f(g(x), h(x)), the computations of g(x) and h(x) can only take half of it 16:05:07 and f gets all of it, because it's a tail call 16:05:10 that's, umm, wow 16:05:15 does that even make sense? 16:05:18 please tell me that makes sense 16:05:29 I don't think so, so let's keep thinking about it until it makes even less sense 16:06:04 -!- calamari has joined. 16:06:08 ais523: so the idea would be, make it so that just piling all the junk from multiple calls together ends up using an impossible amount of RAM 16:06:21 yep 16:06:27 ais523: i.e., because you recurse, and then use more than ten times that, or whatever 16:06:36 so the whole function needs RAM n > n for certain inputs 16:06:41 and it's rejected by the RAM checker 16:06:42 hmm, now I'm reminded a bit of Advice 16:06:50 it's one of the ICFP esolangs 16:07:12 and it's basically just Thue-on-trees, except that if the same number of replacements need to be made on both branches of a tree, it doesn't replace on either 16:07:29 which is a restriction that's perfectly gauged to throw a spanner in the works of typical algorithms 16:07:40 wow so I think I've actually figured out my esolang. 16:08:05 (my solution to programming in it was to make sure that only one replacement was possible at any given time, so that it'd always be split 1/0 everywhere that mattered and thus avoiding a balanced situation) 16:08:20 that applies to subtrees, too, obviously, or it'd be trivial 16:09:18 ais523: incidentally, it's meant to be term rewriting, if it isn't obvious 16:09:20 my language, that is 16:09:33 You guys were talking about entropy without me? 16:09:43 Wait no that's stupid entropy. 16:09:55 elliott_: yep, I figured it was some sort of match-and-unmatch thing, like Anarchy 16:10:22 ("unmatch" is a great name for the operation of creating a data structure from a template) 16:13:46 ais523: hmm, I'm quite worried that the junk value always seems to be one of the parameters to the function 16:13:56 I suppose it's because these functions are pretty simple so far 16:14:22 elliott_: hmm, I'm reminded of Unassignable now 16:14:33 finding workable junk values there was really hard 16:14:36 * :≠ 16:14:41 yay, I can finally type its actual name 16:14:50 * elliott_ is trying fib now, which is interesting because it recurses twice 16:17:13 wow, fib is difficult 16:18:39 fib(Z) = (0, Z); 16:18:39 fib(S(Z)) = (S(Z), S(Z)); 16:18:39 fib(S(S(n))) = 16:18:39 let (a, j) = fib(n); 16:18:39 (b, j') = fib(S(n)); 16:18:40 (r, j'') = add(a, b) 16:18:42 in discard j' = S(j) 16:18:44 j'' = a 16:18:46 a = fst(fib(j)) 16:18:48 b = fst(fib(S(j))) 16:18:50 in (r, S(S(j))); 16:18:52 the problem there is that there's no such thing as fst 16:18:58 indeed 16:20:54 hmm, ah 16:20:56 fib(Z) = (0, Z); 16:20:56 fib(S(Z)) = (S(Z), S(Z)); 16:20:56 fib(S(S(n))) = 16:20:56 let (a, j) = fib(n); 16:20:57 (b, j') = fib(S(n)); 16:20:59 (r, j'') = add(a, b) 16:21:01 in discard j'' = a 16:21:03 (a, j) = fib(j)) 16:21:05 (b, j') = fst(fib(S(j))) 16:21:07 in (r, S(S(j))); 16:21:09 wow, that's longer than it looks in my editor 16:21:11 errr 16:21:13 scratch that 16:21:25 http://sprunge.us/TYBY 16:21:31 oh, and I forgot semicolons 16:22:43 ais523: I suppose there's no problem in letting you use a variable after it's discarded 16:22:58 indeed 16:23:16 although, you could just put a discard list at the end of a function 16:23:20 ais523: the main problem is that it's easy to cheat discard 16:23:28 ais523: by giving it a definition that _isn't_ equivalent 16:23:36 but just happens to work in all the cases you try 16:23:50 should be instant runtime crash if they're different at runtime 16:24:00 I don't see why it's a problem if they're always the same at runtime but defined differently 16:24:06 ais523: that's cheating; you can't do that in the "architecture" of the language 16:24:14 ah, OK 16:24:17 ais523: I mean, on real computers, you don't have to do discard at all! you can just throw away the values 16:24:35 the idea is that you can throw away information as long as you can prove you already have it 16:24:43 which isn't the same thing as just happening to have the right bits 16:24:54 you need to prove you've already computed it redundantly, in essence 16:25:04 hmm 16:26:51 -!- olsner has joined. 16:27:21 ais523: I suppose it could try and prove it itself via term rewriting 16:27:26 not sure it would work though 16:27:40 make it ship with a machine-readable proof, Coq/Agda-style? 16:27:42 ais523: sort of, prolog style 16:27:43 like if you do 16:27:45 a = b 16:27:50 it computes b symbolically 16:27:53 and checks that it's a 16:28:07 ais523: that's also cheating, but more importantly it's really boring 16:28:12 heh, I think that's another operation that I'm planning for Anarchy 16:28:12 because proofs are boring to write 16:28:13 quick, someone summarize the last week of #esoteric for me 16:28:16 elliott_: OK 16:28:22 olsner: boring 16:28:24 olsner: is that possible? 16:28:25 except for just now 16:28:36 but yes, today it's been interesting, the rest of the week, not so much 16:28:40 elliott_: ok, I'll just assume I haven't missed anything then :) 16:29:09 elliott_: yes, everything is so much easier when I resist the urge to not make this a term rewriting language. 16:29:27 term rewriting is great 16:29:34 and instead just make it an awesome term rewriting language. 16:29:36 s/term/graph/g 16:29:44 more languages should do term rewriting 16:30:33 ais523: heh! i think i can use this model to do a kind of uniqueness typing 16:30:50 so this is kind of turning into a spatial and temporal logic graph rewriting language, if that's even a thing. 16:32:08 also nondeterministic because why not. 16:35:19 http://sprunge.us/ENjA 16:35:21 I think this works 16:35:33 the main problem is that you could discard the last world and return the second-last world, which is problematic 16:37:51 ais523: heh, then I thought of a solution but it's just a monad 16:38:16 elliott_: monads in general, or a specific monad? 16:38:21 the io monad 16:38:37 right yes, that became obvious when I clicked on the link 16:38:47 er, no 16:38:51 that sprunge isn't the IO monad 16:39:10 nope, but it becomes clear that IO is how you'd fix it 16:39:24 right 16:39:32 that's so boring though, it doesn't use the reversibility at all 16:39:42 the only additional thing you'd need is like 16:39:50 discard X in E -- E has to have type IO t for some t 16:39:54 and X can have any type 16:40:04 so that you can, e.g., read a line from the terminal without having to print it out later or whatever 16:40:16 (discard X in E has the same type as E, ofc) 16:40:49 -!- sebbu2 has joined. 16:41:02 -!- sebbu2 has quit (Changing host). 16:41:02 -!- sebbu2 has joined. 16:41:12 -!- sebbu has quit (Ping timeout: 248 seconds). 16:41:42 ais523: time to see if I can write reverse : [a] -> [a] 16:43:25 append([], ys) = 16:43:25 discard [] = take(Z, ys) 16:43:25 in (ys, Z); 16:43:25 append(x:xs, ys) = 16:43:25 let (xs', j) = append(xs, ys) 16:43:25 in (x:xs', S(j)); 16:43:30 hmm, that can't possibly work, which is a bad sign 16:43:36 because I can't think of another way to do it 16:43:50 and I also can't see how that's invalid 16:45:03 ais523: hmm, I might pop back to branch 1, which is a completely different language 16:45:19 ais523: http://esoteric.voxelperfect.net/wiki/User:AlisonDiaz603 16:45:59 deleted (I assume you didn't want protection instead :P) 16:46:12 I have just noticed a name in a Wikipedia article which is spelt two different ways in two consecutive paragraphs. 16:48:25 -!- copumpkin has quit (Remote host closed the connection). 16:48:32 ais523: btw, though I'm not as annoyed as oerjan, I think you should contact Graue if spam continues at this rate, at least to give you bot privileges so that you can keep the deletions off recentchanges 16:48:57 elliott_: he'd need to give me the option to set/unset bot privs 16:49:09 ais523: why can't he just set bot privileges for all admins? 16:49:10 rather than just to put them on constantly, because then none of my edits would show up in recent changes 16:49:13 ah 16:49:21 is there a way to do that without giving you crat privs? 16:49:25 I'm also not sure what happens to admin actions marked bot actions 16:49:34 elliott_: yes, but it's nontrivial and may require recentish MediaWiki 16:49:39 *sigh* 16:49:43 admins can set/unset all sorts of flags on Wikipedia 16:49:56 (none of the really important ones, but flags like "can use rollback" are routinely toggled by admins) 16:50:07 ais523: well, whatever, I just think you should contact him to get /something/ done if recent changes continues to be completely clogged with spam 16:50:37 what I'd really like is the AbuseFilter extension 16:50:43 it lets admins configure anti-spam rules 16:51:01 that would be preferable to our current (terrible) capthca system. 16:51:04 captcha 16:51:16 but i have a feeling that graue has Strong Opinions on the Right Way to do this 16:51:37 we could at least have a better captcha 16:51:44 admins can create accounts, right? 16:51:54 yes, for other people as well as themselves 16:51:57 then it doesn't matter if we have an image-only captcha 16:52:06 people who can't use it can ask an admin for an account 16:52:09 it requires an email address, though 16:52:22 as the admin doesn't get to see the resulting password, and it has to be sent /somewhere/ 16:52:31 right 16:52:37 (random fact: for a while, I handled quite a large proportion of Wikipedia's manual account creation) 16:53:14 what was that used for? 16:53:27 mostly usernames that hit the blacklist 16:53:41 like being too similar to another user, or containing blacklisted words, that sort of thing 16:53:48 checking to see if the blacklist should be overriden in that case 16:54:05 (being too similar to someone who registered six years ago and has never edited, for instance, typically I'd allow that) 16:55:47 But five years, hell no! 16:56:00 heh 16:59:36 someone help me forget an idea I just had, please 16:59:49 !perl print (("stay in school", "drop out")[int(rand(2))]) 16:59:52 stay in school 16:59:58 EgoBot: thanks egobot 17:00:07 `run perl -e 'print (("stay in school", "drop out")[int(rand(2))])' 17:00:09 drop out 17:00:11 kallisti: HackEgo is cooler. 17:00:15 You should trust HackEgo instead. 17:00:26 I somehow doubt that. 17:00:37 still MY TIME MANAGEMENT SKILLS ARE FUCKING DISAPPEARING AAAAAAH 17:00:40 @die 2 17:00:40 2 => 2 17:00:44 @die 1d2 17:00:44 1d2 => 2 17:00:46 not that I had any in the first place. 17:00:48 but now they're more important. 17:01:06 Majority opinion points to "drop out" 17:02:06 PRNGs is no way to make important life decisions. 17:03:26 -!- copumpkin has joined. 17:03:30 www.random.org says 1 so "stay in school" it is 17:04:06 !perl print ( int rand(6 > 0) ? "continue living" : "kill yourself" ) 17:04:07 kill yourself 17:04:09 lol 17:04:30 I'm bad at Russian roulette 17:04:34 er 17:04:36 except 17:04:36 -!- copumpkin has quit (Remote host closed the connection). 17:04:38 I fucked up the code 17:04:42 so I'm just bad at programming 17:04:46 !perl print(int rand(6 > 0)) 17:04:46 0 17:04:55 !perl print(rand(6 > 0)) 17:04:56 0.262715389094414 17:05:01 -!- copumpkin has joined. 17:05:07 is 6 greater than 0 17:05:12 Yes 17:05:23 !perl print ( (int rand 6) > 0 ? "continue living" : "kill yourself" ) 17:05:24 continue living 17:05:25 thanks 17:05:28 yesssss 17:07:19 !perl print int rand 6 17:07:19 1 17:08:05 !perl print int rand 6 17:08:05 0 17:08:07 !perl print int rand 6 17:08:08 2 17:08:09 !perl print int rand 6 17:08:10 3 17:08:26 you're all being terrible at distracting me. 17:09:37 echo '#!/bin/perl' > bin/russianroulette && echo 'print ( (int rand 6) > 0 ? "continue living" : "kill yourself" )' >> bin/russianroulette && chmod +x bin/russianroulette 17:09:56 `run echo '#!/bin/perl' > bin/russianroulette && echo 'print ( (int rand 6) > 0 ? "continue living" : "kill yourself" )' >> bin/russianroulette && chmod +x bin/russianroulette 17:09:58 No output. 17:10:07 `russianroulette 17:10:07 `rm bin/russianroulette 17:10:10 NOOOOOO 17:10:11 ​/home/hackbot/hackbot.hg/multibot_cmds/lib/limits: /hackenv/bin/russianroulette: /bin/perl: bad interpreter: No such file or directory \ /home/hackbot/hackbot.hg/multibot_cmds/lib/limits: line 5: /hackenv/bin/russianroulette: Success 17:10:27 No output. 17:10:33 Success 17:11:29 -!- monqy has joined. 17:11:52 monqy: success 17:12:00 hi 17:12:19 monqy: monqy :elliott 17:12:29 hi 17:12:32 hey 17:12:46 zah 17:12:55 speaking of success, I finished the python yesterday/lastnight 17:13:37 hopefully that means no more for a while. will likely have to do c++ next quarter though :( why is everything bad 17:13:48 "On the one hand, Java was slow, bloated, and not too portable. On the other hand, Inferno was quick, small, portable*, and marketed by AT&T. So naturally Java became popular." 17:14:14 inferno? that any good? 17:14:39 http://en.wikipedia.org/wiki/Inferno_(operating_system) 17:15:01 tetris excitement 17:26:36 ais523: quick, talk about Feather 17:35:52 ais523: that wasn't quick! 17:52:05 elliott_: obviously he wrote an IRC client in Feather 17:52:08 and discussed in the pass. 17:52:10 t 17:52:11 the passt 17:52:44 using the Feather inerpretre that's written in Feather. 17:52:55 ais523: confirm/deny 17:53:22 ais523: probably too insane to do either. 17:53:25 er 17:53:28 elliott_: ^ 18:06:20 is prototype inheritance in JS a real, built-in language fearture? 18:06:23 -!- zzo38 has joined. 18:06:27 or just a stupid hack? 18:07:34 JavaScript prototype inheritance is a language feature. I'm not sure how that's related to whether it's a stupid hack or not. 18:08:58 kallisti: /all/ Feather interpreters are written in Feather 18:09:04 if they weren't, they wouldn't be Feather interpreters, by definition 18:09:27 this confused me for a bit, before I realised that you could write a Feather interp as a polyglot between Feather and some other language 18:09:33 and as long as everything had the same meaning, it'd work fine 18:10:50 .. 18:10:55 elliott_: But is it in the language itself or just in the runtime that could be altered? How is it different from prototype inheritance implemented in C? Would this make C object oriented? :D 18:11:06 ais523: you realize that doesn't really make any sense at all right? 18:11:16 nooga: (a) it is part of the language itself. it must be implemented in the runtime, of course, like all language features. 18:11:17 I'm asking because I have an argument with guy that states that JS is legit OO language 18:11:27 nooga: (b) C does not have prototypes... 18:11:31 kallisti: there is a reason that Feather drives people who attempt to understand it crazy 18:11:40 I think you're beginning to see the edges of it 18:11:42 nooga: of course JS is an object-oriented language. 18:11:47 nooga: Do you know of Self? 18:11:56 yeah 18:12:06 the reason it's so maddenning is that you're constantly struggling with the issue of whether Feather makes sense or not 18:12:14 nooga: also, you can do OO quite well in C 18:12:21 ais523: i know taht 18:12:31 but it does not make C an OO language 18:12:34 and that's my point 18:12:37 you can even setup vtables by hand and get it working exactly like a saner version of C++ if you like 18:13:08 nooga: JavaScript has language support for objects with self-reference and constructors. JavaScript has built-in language support for prototypes via the .prototype functionality. 18:13:09 ais523: I've read a book about it 18:13:19 It is unquestionably a real object-oriented language based on prototypical inheritance. 18:13:42 It's also not a very good language in general, but that's an orthogonal issue. 18:13:55 elliott_: understood 18:14:00 elliott_: how does JS do delegation, or the equivalent? I seem to remember something like making the prototype a function that looks at the superobject's prototype 18:14:22 ais523: I don't remember exactly how it works; I've tried to forget as much JS as possible. 18:14:27 http://ejohn.org/blog/simple-javascript-inheritance/ 18:14:33 but this is just completely wrong 18:14:51 nooga: That's just syntactic sugar. 18:14:54 i could write OO programs in C with less syntactic clutter 18:14:55 Well. 18:14:57 elliott_: why do you hate JS as much as you do? I don't understand it well enough to truly hate it 18:15:03 Half syntactic sugar for delegation, half attempting to make it look like class-based inheritance. 18:15:28 ais523: I don't really hate it, it's just not very pleasant to use; a large part of that is because browser APIs, especially the DOM, are terrible. 18:15:33 elliott_: well, class-based inheritance is a special case of prototype-based inheritance 18:15:34 ais523: But also its scoping is awful. 18:15:44 elliott_: isn't it block-scoped? 18:15:47 well, sometimes? 18:15:50 oh, I see what you mean 18:16:00 ais523: no 18:16:02 ais523: it's function-scoped 18:16:09 ouch 18:16:13 seriously? 18:16:16 ais523: for (var i = ...; ...; ...) { ... }; /* surprise, i is still in scope! */ 18:16:25 (and any previous "i" in the function overwritten) 18:16:40 what about {for (var i = …; …; …) { … };} /* is i still in scope here? */ 18:16:46 i don't think that's valid 18:16:47 people do 18:16:50 (function() { ... })() 18:16:52 for closures 18:16:54 wow 18:17:03 another thing I dislike about JS is how lax and implicit its coercions are 18:17:06 and conversions, too 18:17:17 hmm, that would be a fun use for C++ lambda syntax: [](){ … }() 18:17:26 although {} works just as well in C++ 18:17:42 elliott_: that's just typical dynamic language typing syndrome 18:17:47 at least, it's endemic to both JS and PHP 18:18:11 ais523: Python and Ruby don't suffer from it 18:18:16 ais523: Perl sort of does, but it's at least consistent about it 18:18:24 Perl uses a different solution to the problem 18:18:28 because it separates its string and number operators strictly 18:18:37 Python and Ruby make sure that values are always clear on their own type 18:18:39 "Some languages, such as Perl, began as scripting languages[3] but were developed into programming languages suitable for broader purposes. Other similar languages – frequently interpreted, memory-managed, or dynamic – have been described as "scripting languages" for these similarities, even if they are more commonly used for applications programming. They are usually not called "scripting languages" by their own users." 18:18:44 err, Perl users don't call it a scripting language? 18:18:44 whereas Perl makes sure that contexts are always clear on their own type 18:18:54 elliott_: I call it a scripting language when I use it for scripting 18:19:03 haha 18:19:03 something like TAEB, it doesn't really feel like I'm using a scripting language, though 18:19:20 it feels like I'm using a not-really-designed-for-scripting subset of a scripting language 18:19:27 * elliott_ thinks Perl is probably okay for scripting, but wouldn't use it for anything non-scripty. /me also considers it a flaw when a language is only good at one 18:19:45 I agree, so I moved it. Not an admin tho so history will look weird. Elfguy 20:37, 16 August 2005 (UTC) 18:19:46 --[[Talk:Scripting language]] 18:19:49 -!- Klisz has joined. 18:19:52 elliott_: perl does have pretty good scoping rules though. 18:19:59 in regard to the above. 18:20:03 about JS scoping 18:20:04 kallisti: nowadays 18:20:13 Perl is one of the few modern languages with proper dynamically-scoped variables 18:20:14 it took multiple tries to get it right 18:20:30 elliott_: Perl did what it usually does, and put every sort of scoping it could think of into the language 18:20:32 also, I believe Python is function-scoped as well for local variables. 18:20:46 it is 18:20:53 good. 18:20:54 .. 18:20:57 but at least variables can't be referenced before definition 18:20:58 package scope, dynamic scope, lexical scope, you can even have truly global scope if you like (this requires you to name your variables starting with a control character) 18:21:00 (in js they're just undefined) 18:21:06 and at least it doesn't /pretend/ to have a declaration keyword (var) 18:21:20 ais523: control character? seriously? 18:21:28 elliott_: yes; there's sugar to write it in ASCII 18:21:36 what sugar? 18:21:42 I like how Python is sometimes less strict than Perl, mainly regarding variable declaration (or lack thereof) 18:21:42 ${^This_starts_with_control_T} 18:21:44 -!- derrik has joined. 18:21:49 awesome 18:21:50 but it's stored as a literal control-T internally 18:21:59 kallisti: nothing's looser than strict/warningsless perl 18:22:23 incidentally, it's 2011; why doesn't perl have a flag to enable both strict and warnings? 18:22:30 and you can put a literal control-T in the source, if you really want to 18:22:52 elliott_: I believe they want it to be module-specific. This is why the -w flag is discouraged. 18:22:56 elliott_: because scripts where you want strict and warnings, which is ones that are longer than oneliners, are scripts where there's no big loss in writing "use strict; use warnings;" 18:23:13 ais523: the loss is that it takes time and annoys me :P 18:23:13 because -w is applied globally. 18:23:15 whereas for the really insane golfing, poetry, etc, you probably want them off 18:23:18 kallisti: it is? seriously? 18:23:23 yes. 18:23:34 kallisti: are you muddling it with -W, which is very very global? 18:23:42 maybe? 18:23:50 I thought -w turned on warnings in the perl interpreter 18:24:06 which is not a module-specific thing. 18:24:14 i hate js fanboys 18:24:17 -w sets the global variable ${^W} 18:24:18 anc C++ fanboys 18:24:23 which turns on warnings 18:24:28 so... yes? 18:24:29 but it can be turned on and off scopely as usual 18:24:33 and, especially, PHP fanboys 18:24:34 it's just that most modules don't start "no warnings;" 18:24:43 right. 18:24:47 so because -w changes the default warning setting from off to on, it affects them too 18:24:59 -W turns on warnings regardless of "use warnings;" or "no warnings;" or ${^W} or anything 18:25:06 ah okay. 18:25:46 (btw, you can golf ${^W} down to $^W because the name's one char long, and further to $ followed by a literal control-W) 18:25:59 -!- Klisz has quit (Quit: You are now graced with my absence.). 18:26:04 Larry -Wall 18:26:23 elliott_: incidentally, aside from it being a requirement for certain uses of Getopt and $_ hacks, I haven't really used dynamic scope much in Perl. 18:26:26 I can't remember what -a does 18:26:34 and why would you turn on automatic line-ending handling twice? 18:26:41 kallisti: it's good for configuration settings, generally 18:26:47 for instance, whatever stdout is 18:26:58 ais523: you know the options for Larry? 18:26:59 common lisp puts it to good use like that 18:27:22 elliott_: in the Crawl codebase, I've seen a class whose objects are dynamically-scoped booleans, using RAII 18:27:34 it really confused the person who asked me for help with it, because they didn't understand it 18:27:44 ais523: ouch 18:27:47 if the code were RAIIing everywhere, it'd probably be fine, but it's the only bit of RAII I've seen in the code 18:27:55 which just makes it more confusing 18:28:01 Awk Traps 18:28:01 Accustomed awk users should take special note of the following: 18:28:01 · A Perl program executes only once, not once for each input line. You can do an implicit loop with "-n" or "-p". 18:28:17 -p is great for golfing 18:28:24 ais523: -a turns on autosplit mode. I'm not sure if someone else has already said this or not. 18:28:27 to the extent that many programs, you actually write #!perl -p at the start 18:28:36 kallisti: nope 18:28:39 kallisti: hmm, I thought that was -s, perhaps I was confused 18:28:46 * ais523 perldoc perlrun 18:28:49 ais523: I just find it funny that it has to be pointed out that lines run once 18:29:04 ah, -a is autospit, -s parses command-line arguments 18:29:07 ais523: why not "man perlrun" 18:29:15 elliott_: plenty of languages have an implicit loop 18:29:32 also, because I'm used to perldoc nowadays for Perl-related things because it has all the manpages and more stuff beyond that 18:29:47 you can use perldoc -f to get a section of perlfunc, you can't do that with man, for instance 18:29:54 and perldoc and man produce identical output for the manpages 18:30:02 not identical 18:30:03 I think; reasonably identical, at least 18:30:14 oh, the wrapping's different 18:30:28 I think I prefer right-ragged to ASCII-justified 18:31:00 the status bar is different, more importantly 18:31:04 anyway, if you prefer that, set man to do that 18:31:28 elliott_: oh right, man's overriding my less settings, perlrun isn't 18:31:28 ais523: err, both are ragged-right here 18:31:36 and, hmm, indeed 18:31:47 man's normally justified, I just assumed it'd be for perl docs too 18:32:06 presumably the manpages are actually generated as manpages, not via nroff 18:32:16 but, hmm 18:32:23 `run echo 'open 0;print<0>' > quine.pl && perl quine.pl 18:32:26 open 0;print<0> 18:32:40 totally pure guys. 18:33:00 $ l `man -w perlrun` 18:33:17 hmm, it looks like nroff 18:33:34 .\" For nroff, turn off justification. Always turn off hyphenation; it makes 18:33:36 .\" way too many mistakes in technical documents. 18:33:39 ah, interesting 18:33:52 it looks like some workaround for nroff specifically in pod2man 18:34:02 it's conditioned on nroff being the implementation used, and wouldn't happen in groff or troff 18:34:08 what's the fastest way to forget how to write assembly code? 18:34:13 `rm quine.pl 18:34:15 No output. 18:34:19 elliott_: in which language? 18:34:27 spanish 18:34:40 I think you'd have to learn how to write asm in spanish first 18:34:44 in order to forget it 18:34:55 indeed 18:35:40 ais523: (what did you actually mean by that question?) 18:36:40 which asm variant, I think I meant 18:36:40 as in, x86 asm, 6502 asm, etc 18:37:09 x86(-64, ostensibly) 18:37:15 I suppose if you wanted to forget asm for a particular platform, you could just learn it for another platform that's much nicer 18:37:20 go work on SPARC asm or something for a while 18:37:28 why do you want to forget x86 asm, incidentally? 18:38:00 ais523: to prevent me from trying to write a horrible thing 18:38:12 it might be easier to fix the reason rather than the immediate problem 18:38:12 elliott_: oh, err, uh-oh 18:38:12 elliott_: you'll fail 18:38:23 (if I demoralize elliott_ enough, that'll have the same effect with less pain) 18:38:44 elliott_: writing a horrible thing will make you a worthless human being, even if you succeed; especially if you succeed, possibly more so if you fail 18:39:05 ais523: see, now what'll happen is I'll end up writing it anyway, and then I'll get all sad because you're mean 18:39:10 LOOK AT WHAT YOU HAVE DONE 18:39:18 elliott_: you don't want to make me mean, do you? 18:39:28 not even retroactively? especially not retroactively? 18:39:42 !feather ais523->mean = true 18:39:51 that looks nothing like Feather 18:40:02 you'd have to <<= me with a slightly modified ais523 18:40:04 you can change Feather's syntax, can't you? 18:40:07 probably through a wrapper function, to prevent a time loop 18:40:18 !feather loads the Alternate Standard Feather Library which is more popular nowadays 18:40:23 that reskins the syntax 18:40:25 elliott_: well, yes, I guess, but at some point it stops being Feather, and starts being a different language with similar semantics but different syntax 18:41:02 ais523: changing <<= to = and adding sugar for record access doesn't seem that drastic 18:41:24 hmm, I guess so 18:41:29 but that'd be negative sugar 18:41:36 as you would need just a space there for record access, typically 18:41:54 ais523: in the future, people like to put spaces in identifiers 18:42:05 so that was added to the ASFL due to popular demand 18:42:06 also, hmm, I wonder if the value of ais523 mean would be shared with other values 18:42:07 retroactively 18:42:34 you could do "ais523 mean <<= true" (and probably get yourself stuck in a time loop), but if it was sharing with other booleans at the time, that'd be equivalent to "false <<= true", which, umm, is probably a bad idea 18:42:46 (this is assuming you have sugar for false and true, which you probably do) 18:43:02 false <<= true looks set to be even more fun than false become: true 18:43:25 what happens if you do, e.g., x <<= [x] where [x] is the singleton list of x? 18:43:33 Feather rapidly allocates memory? 18:43:36 it doesn't recurse 18:43:46 you get a list containing the metaold value of x 18:43:57 however, that point in the code would be evaluated again, unless something stopped it 18:44:07 ais523: hmm, is there any way to make a cyclic structure in Feather? 18:44:21 <<= is incredibly unsafe; if it doesn't change some previous control flow behaviour of the program, you get a time loop 18:44:42 so people will probably normally use sugar around it to use some safer operation, such as "add currently nonexisting method" 18:45:08 elliott_: the trick would probably be to use the arbitrary number 18:45:10 s/people/ais523/ 18:45:28 you can't have a true cyclic structure, but you can have a retroactively cyclic structure 18:45:52 in any case my 4D logical graph rewriting language is going to.. what's the word.. baller. 18:45:56 oh 18:46:09 ais523: Feather concurrency sounds like fun 18:46:14 anyone taking part in ioccc ? 18:46:18 (that is, any test you perform to try to demonstrate it not cyclic, it retroactively becomes just cyclic enough to prevent that test working; if you do something that would be an infinite loop on a cyclic structure, you get an infinite loop) 18:46:21 nooga: Gregor and ais523 18:46:23 nooga: I am, Gregor is 18:46:30 I do feel like writing something in C 18:46:44 just not sure if I want to write obfuscated C, or why I would bother trying to make an entry. 18:46:53 ais523: here's a fun concurrency strategy: if conflicts occur, retroactively use a different ordering of threads instead 18:46:59 OMG I missed Featherchat??? 18:47:04 elliott_: brilliant 18:47:07 kallisti: fame and glory 18:47:12 really, I'm not going to even attempt concurrency in Feather 18:47:15 Just write whatever in C according to the program you want to write specifically 18:47:22 kallisti: May as well not bother, as I'm going to win. 18:47:26 it's sort-of like trying to do concurrency in Haskell, only worse 18:47:29 Gregor: there are multiple winners 18:47:44 ais523: Only one "best in show" (or whatever they call it) 18:47:45 ais523: concurrency in haskell works brilliantly 18:47:49 Gregor: I'm not aiming for best in show 18:47:51 tyvm 18:47:58 but for small program, and rules abuse 18:48:15 elliott_: indeed; but you need external libraries, or else for the compiler to deduce it as an optimisation 18:48:20 ais523: Actually, I want them to invent a category for me. 18:48:24 (external = not writable in Haskell) 18:48:25 But failing that, I'll take best in show X-P 18:48:35 ais523: by "concurrency", I just meant lock-step or whatever 18:48:38 not native threads 18:48:42 hmm, right 18:48:47 you'd have to change the entire execution model of the program 18:48:55 but the worrying thing is, this is Feather, and you can actually /do/ that 18:49:01 in any case my 4D logical graph rewriting language is going to.. what's the word.. baller. 18:49:09 Graphs are nondimensional you eejit. 18:49:28 okay fine well what's a graph except now it has distances in a 4D space. 18:49:46 kallisti: a labeled-edge graph? 18:49:59 (do the positions matter in 4D? or just the distances?) 18:50:07 oh? a labeled-edge GRAPH you say? 18:50:10 kallisti, distances? 18:50:11 What? 18:50:14 ais523: the position I think? 18:50:23 maybe just distances? both? -shrug- 18:50:23 Graphs... don't have distances inherently. 18:50:36 Phantom_Hoover: indeed; but you can certainly define a sort of graph that does 18:50:36 Phantom_Hoover: believe it or not I am actually familiar with graph theory 18:50:45 and they are in fact useful 18:50:47 You're just going to be assigning labels to edges based on some embedding of the graph. 18:50:54 Phantom_Hoover: that's why I said labeled-edge graph 18:51:08 Oh, right. 18:52:13 kallisti, but why 4D? 18:52:17 I'm thinking only distances or relevant, so it may not really have 3 spatial dimensions. 18:52:25 3 = 4 18:53:01 Phantom_Hoover: going for reversability, the 4th dimension would be forward and backward in computation steps. 18:53:05 My guess is that the only thing actually having an embedding somewhere is going to change is the fact that the triangle inequality imposes limits. 18:53:13 kallisti, um... 18:53:52 Phantom_Hoover: nah, if you know nearly all the sides and diagonals of a hyper-n-gon, then that's going to lock in the location of the points, thus restricting the other sides and diagonals 18:54:06 the value of n depends on the number of dimensions involved 18:55:08 in any case whether or not it actually corresponds to a 3 dimensional space is irrelevant. I don't think I'm going to keep track of position but instead just do distance relationships. 18:55:34 But as ais523 says, you need to know position to tell if the distance relationships are meaningful. 18:55:59 meaningful in what sense? can't I just not care? 18:56:15 you possibly can not care 18:56:16 Sure, but then why call them distances at all? 18:56:22 the problem is wondering about whether or not you have reason to care 18:56:24 You're just assigning arbitrary numbers to edges. 18:56:36 ais523: argh, I'm trying to think of how the infinite division memory model works and it's so confusing 18:56:51 as in, do you have a reason for them to act like distances? and if so, is it just triangle inequality, or do you need more than that? 18:57:01 ais523: not really no. 18:57:15 ais523, BtW, your hyper-n-gon thing might just be a special case of the triangle inequality? 18:57:16 no reason for them to be distances. 18:57:21 Phantom_Hoover: *general case? 18:57:32 and it is, sort-of, but can lead to equalities as well as inequalities 18:57:33 f(x) = 1 : f(x) is easy to reject, because f^M(x) = 1 + f^M(x) 18:57:45 No, I think the triangle inequality results in it? 18:57:49 "The worst example of this sort of thing in my lifetime, and arguably in the entire history of science, has been the AGW (anthropogenic global warming) panic. Now that the wheels are falling off that juggernaut, I’m starting to hear ordinary people around me wonder how I knew it was bullshit and hot air so much in advance…" --esr 18:57:54 * elliott_ gets popcorn 18:58:12 ESR is a global warming denialist? 18:58:17 ais523: this surprises you? 18:58:18 hmm, I'm not massively surprised 18:58:25 I wouldn't have been surprised by the opposite either, though 18:58:45 think of an idiotic far-right libertarian position; if esr doesn't have it, you should be surprised 18:58:59 but there are idiotic far-right libertarian positions that contradict each other 18:59:11 ais523: indeed 18:59:43 I've discovered that the idiotic far-right libertarian at my school is a) crazy and b) probably an actual sociopath. 19:00:10 ais523: the nodes corresponding to a physical space was just an interesting idea, but the main proof of concept is the non-deterministic time-based shenanigans (we seem to be doing a lot of those lately) 19:00:23 'Lately'. 19:00:24 "Rhetoric that mixes science with the tropes of eschatological panic." actual quote 19:00:26 yep, especially as I was playing Braid yesterday 19:00:38 Phantom_Hoover: lately? 19:00:44 Feather transcends the timeline; ais has always not being developing it. 19:00:48 oh 19:00:54 hey, I work on it sometimes 19:01:03 I even did NEF just fine without getting very bad 19:01:04 *very mad 19:01:06 ais523: is Braid actually worth playing? I've been put off by how pretentious the developer is 19:01:08 although I'm not sure it's useful 19:01:16 (I think I see '523' as ais' last name now.) 19:01:27 elliott_: it's, umm, reasonably pretentious plotwise, but the graphics are pretty and the puzzles are interesting 19:01:38 the "no filler" rule is really grating, though 19:01:42 after a while you start wishing for filler 19:01:45 heh 19:02:04 it's also very difficult 19:02:18 which is arguably good, as it means you won't reach the ending, which is the most pretentious part 19:02:36 :D 19:02:42 :D 19:03:02 oklopol, come on, you're meant to join in there. 19:03:03 Phantom_Hoover: Can AII be a metaphor for globalisation please. 19:03:25 Like, after you finish the single-player campaign, "IT WAS GLOBALISATION ALL ALONG" pops up and you have to "OH I GET IT" to get back to the menu. 19:03:31 Yes. 19:03:32 ais523: would a 3D space be easier to manage if I restricted the graph from forming cycles with its present edges. (think of present edges as just... normal graph edges) 19:03:42 -!- ais523 has quit (Read error: Connection reset by peer). 19:03:46 Phantom_Hoover: Except clicking "OH I GET IT" just makes it change into "VERY CLEVER". 19:03:48 I fixed another thing in Super ASCII MZX Town game 19:03:54 Phantom_Hoover: And you have to click it again. 19:04:07 -!- ais523 has joined. 19:04:32 < kallisti> ais523: would a 3D space be easier to manage if I restricted the graph from forming cycles with its present edges. (think of present edges as just... normal graph edges) 19:04:35 [error] Closing Link: 147.188.254.189 (No more connections allowed in your connection class) 19:04:36 ? 19:05:00 ais523: get off the internet, low-class scum. 19:05:04 kallisti: yes, in fact you could do it even in a 2D space, but then you basically have a tree, not a graph (it becomes an actual tree if you give it a root) 19:05:38 ais523: wow, so a tree is like... a graph without cycles? 19:05:47 * elliott_ facepalm 19:06:00 kallisti: that is the graph-theoretic definition of "tree", yes 19:06:15 (don't forget it's connected!) 19:06:17 rooting it gives you the programming-language definition of "tree" 19:06:24 well, OK, it's not a tree if it isn't connected 19:06:27 it has to be connected to be a tree 19:06:34 otherwise it's a forest (actual technical term) 19:06:36 "No more connections allowed in your connection class" 19:06:37 In English, this means the server is full for people like you, at least for now. People from different providers might still be able to connect. You might see this sometimes on servers that you were able to connect to just recently. Try a different port on the same server (other than 6667) or try a different server for a while. 19:06:39 how helpful 19:06:39 I made barrier monad transform now. newtype BarrierT f b m t = BarrierT { runBarrierT :: m (Either t (f, b -> BarrierT f b m t)) }; 19:06:50 "people like me" 19:06:52 they exist? 19:06:55 lol 19:07:14 ais523: are you sure a tree has to have a root to be a tree in computer science? seems kind of arbitrary. 19:07:27 I mean, I know they typically do... 19:07:50 kallisti: it's not arbitrary; it's hard to define an ADT without one 19:07:56 kallisti: I'm talking about the usual recursive definition in terms of trees having a possible value (perhaps only if they have no branches), and 0-n branches 19:07:59 that naturally leads to a route 19:08:07 *root 19:08:29 you can imagine a sort of "doubly-linked tree" which wouldn't need one, but it probably wouldn't be very useful given the typical applications of trees in CS 19:08:39 ais523: that doesn't encompass, e.g. data Tree a = Branch (Tree a) (Tree a) | Leaf a 19:08:44 because n is fixed 19:08:53 you can imagine a sort of "doubly-linked tree" which wouldn't need one, but it probably wouldn't be very useful given the typical applications of trees in CS 19:08:58 ais523: the closest thing is a tree zipper 19:09:01 which /is/ very useful 19:09:01 I honestly haven't considered efficiency at all for this language. 19:09:11 list zippers are what we use instead of doubly-linked lists, after all 19:09:34 elliott_: right, indeed; I was talking about not needing a root, rather than not having the links back (which are potentially useful for reasons unrelated to rooting) 19:09:50 rewriting nodes based on whether or not they satisfy logical predicates in a huge graph that never shrinks is probably not going to be fast. 19:10:03 also, the "n is fixed" is a special case; that's a binary tree, which is a case of a tree where n = 0 or 2 19:10:43 fair enough, but the n=2 case has no value 19:10:58 also, what about data Tree a = Branch a (Tree a) (Tree a) | Leaf? that has a value only when n=2 19:11:41 perhaps if I restrict the kinds of predicates that one can use, then I can make the lookup algorithm fairly efficient.. 19:11:57 elliott_: a conditional value is fine as well, I think 19:12:06 conditional on n, or maybe even on something else 19:12:23 kallisti: part of the reason I haven't implemented eodermdrome is that I can't think of an efficient way to do it 19:12:50 ais523: in particular I intend to restrict the rewrite rules so that subgraphs cannot be replaced in one rewrite. 19:13:11 well, single nodes are subgraphs I guess. 19:13:15 ais523: didn't oklopol come up with an efficient way? Phantom_Hoover? 19:13:25 elliott_: I think oklopol was working on it, but I can't remember the outcome 19:13:40 I thought the efficient way has been well-known in here for ages. 19:13:56 ais523: can we delete [[Excela]] so people stop vandalising it? 19:13:58 hmm, come to think of it, indexing by degree, and context degree up to n levels, would be pretty efficient 19:14:03 ais523: you should probably protect it, anyway 19:14:17 elliott_: if it gets spammed much more, I'll put an appropriate protection level on 19:14:20 is it anons or registered users? 19:14:23 ais523: it just got spammed 19:14:26 http://esoteric.voxelperfect.net/w/index.php?title=Excela&action=history 19:14:32 I don't think it's going to stop 19:14:34 and it's registered users 19:14:46 it's every three days, roughly 19:14:47 I'm thinking I could probably make it efficient if I restrict the kinds of rewrite rules and predicates that can be expressed, and by using other data structures besides a graph in the implementation, at the expense of more memory overhead. 19:14:52 elliott_: you just made me revert your revert by mistake! 19:14:53 sometimes more often 19:14:55 * ais523 reverts 19:14:57 for a language that, as far as I can tell, does not ever free memory. 19:15:18 unless a garbage collection or manual memory management scheme can be created... but I have no idea how that would work. 19:15:35 elliott_: with those spambots, in the past, all the spamming they've done has been confined to one article, but moves to a different one if you protect it 19:16:06 kallisti: most modern languages never free memory 19:16:28 ..wha? is this some weird technical distinction I'm missing? 19:16:40 I'm pretty sure they do. 19:16:48 no they don't 19:16:56 Python has no free(), Perl has no free() 19:16:57 elliott_: do you mean "return memory to the OS" by "free"? 19:17:00 Ruby has no free() 19:17:02 Haskell has no free() 19:17:06 Common Lisp and Scheme have no free() 19:17:12 ah, no, you mean "don't have an explicit command to free" 19:17:13 s/language/implementation/ 19:17:18 ais523: no, I mean "don't free" 19:17:27 elliott_: $x = undef; will free the previous thing that $x referred to if it was the only reference 19:17:32 the fact that most implementations optimise things by discarding memory that they can prove won't be referenced in the future is irrelevant tot he language 19:17:38 ais523: no it won't 19:17:45 elliott_: and even run its finalisers 19:17:50 s/language/implementation/ --debate solved 19:17:53 well, finalisers are usually implementation-specific 19:17:58 and unpredictable 19:18:10 for instance, I bet Jython won't run finalisers if you do x = None 19:18:12 elliott_: they're part of the language in Perl 5 and predictable; this sort of thing may be /why/ it only has one impl 19:18:14 because it doesn't use refcounting 19:18:23 does Python even have finalisers? 19:18:30 yes. 19:18:35 __del__ 19:18:40 (also, is "finaliser" or "destructor" the more common name nowadays?) 19:18:49 destructor I believe 19:18:51 is what I see the most. 19:19:01 finaliser 19:19:07 ais523: didn't oklopol come up with an efficient way? Phantom_Hoover? 19:19:17 destructor is Python jargon meaning something else, I think, which is why kallisti might see it more often 19:19:25 certainly I always see "finaliser" in memory-management texts 19:19:39 elliott_: no I see it in my Java and C++ classes as well. 19:19:40 I concluded that implementing Ullman's algorithm with appropriate specialisations would get the match stage (the real time sink) down to polynomial time. 19:19:59 I normally go with Java terminology for javaish-OO stuff, bceause Java's implementation on the javaish-OO world is quite large 19:20:05 Phantom_Hoover: I thought there was something simpler than that 19:20:14 (we really need a name for the Java/C++/C#ish OO to distinguish it from Smalltalky OO) 19:20:18 ais523: well, they're called finalisers in java 19:20:22 elliott_: I know 19:20:29 ais523: anyway, destructors are something subtly different, I believe 19:20:29 that's why I used that name without really thinking 19:20:37 ais523: they're things you run explicitly 19:20:40 cf. C++ 19:20:42 even though you aren't meant to use finalisers in Java ever nowadays 19:20:45 Well, Ullman's algorithm optimises subgraph matching down to polynomial if you have constant subgraphs. 19:20:49 because they're so unpredictable 19:20:54 Which is the case in Eodermdrome. 19:21:04 ais523: I think it's usually called class-based OO 19:21:06 ais523: why unpredictable? just because GC is? 19:21:09 kallisti: smalltalk is class-based 19:21:17 oh.. 19:21:23 right. I was thinking of self and friends. 19:21:28 elliott_: in Java, there's no guarantee that they're ever actually run at all 19:21:37 ais523: sure; that doesn't seem relevant to me 19:21:46 and I'm not sure if it's purely GC-related 19:21:48 GHC's finalisers have the same property and they're used with abandon 19:21:48 although it probably is 19:22:18 also, hmm, what context do GHC finalizers run in? some suitable IO monad that's made to happen at an arbitrary time relative to other events? 19:22:39 http://hackage.haskell.org/packages/archive/base/4.4.1.0/doc/html/Foreign-ForeignPtr-Safe.html 19:22:53 your question is incoherent and contains type errors, so i'll just link you docs instead :P 19:23:01 indeed, it contains type errors 19:23:10 I missed that they aren't Haskell 19:23:21 elliott_: your mouth is a type error 19:23:26 ais523: huh? 19:23:41 well, they're run via the FFI 19:23:42 -!- oerjan has joined. 19:23:43 oh, http://hackage.haskell.org/packages/archive/base/4.4.1.0/doc/html/System-Mem-Weak.html also has finalisers 19:23:45 ais523: no they're not 19:24:11 "A finalizer is represented as a pointer to a foreign function…" 19:24:23 well, OK, but that's not relevant: http://hackage.haskell.org/packages/archive/base/4.4.1.0/doc/html/Foreign-Concurrent.html 19:24:35 and the System.Mem.Weak finalisers are just actions too 19:25:49 so the answer is, they have to return a marshallable type, or an IO of a marshallable type 19:26:01 and making them pure functions is obviously ridiculous, so in practice, they're IO actions 19:27:06 Hey guys if you're libraring can you see if you can find an implementation of that algorithm. 19:27:55 ais523: huh? 19:27:59 so the answer is, they have to return a marshallable type, or an IO of a marshallable type 19:28:03 this is wrong and/or makes no sense 19:28:31 ah, I saw type FinalizerPtr a = FunPtr (Ptr a -> IO ()) 19:28:42 then looked up the definition of FunPtr, and saw its restriction on types it accepted 19:28:53 and missed that FinalizerPtr had a stronger restriction (specificlaly, that it returned IO ()) 19:28:55 ais523: you read wrongly 19:29:13 well, it's true that the types are always used that way in finaliser use 19:29:16 elliott_: look, it's pointless linking me to docs if you're going to disagree with everything that I glean from them 19:29:20 even if I'm wrong 19:29:21 but it's quite irrelevant, since the FinalizerPtr takes a Ptr 19:29:33 so it's irrelevant whether the a being finalised is marshallable or not 19:29:51 I didn't say it was relevant 19:29:55 I was talking merely about the return value 19:29:57 which is IO () 19:29:57 ais523: I link you to documentation because I can't think of any way to answer your question because it doesn't make any sense; I can just ignore false things you deduce from it if you want *shrugs* 19:30:39 the return value is IO (), the argument isn't IO anything, thus the finalizer is an IO action 19:30:43 which is what the question was in the first place 19:30:54 err, "the argument isn't IO anything"? 19:32:01 elliott_: a function of type IO a -> IO a isn't really an IO action 19:32:09 functions aren't IO actions 19:32:15 IO actions look like IO a for some a 19:32:28 ah, aha 19:32:29 (id m :: IO a) for some m, a is certainly an IO action 19:32:33 terminology clash? 19:32:37 and (IO a -> IO a) is certainly a function from an IO action to an IO action 19:32:53 the IO /value/ is what's referred to as the action 19:32:56 ais523: no, just the typical non-Haskeller mistake of assuming something like (IO a) is a "function of 0 arguments" 19:33:07 thus assuming that if (IO a) is an action then (... -> IO a) must be too 19:33:13 at least, that's how I usually see that mistake being made 19:33:22 hmm, I think I might have made it based on different reasoning 19:33:27 it's because of the whole do-sugar thing 19:33:43 it's because you can >>= onto a function of type x -> IO a 19:33:51 well, OK 19:33:54 and that's a behaviour of >>= rather than of IO 19:34:00 but it feels like a behaviour of IO unless you concentrate 19:34:07 anyway, can anyone here get behind ACM paywalls who isn't too legalistic to share the spoils? 19:34:29 ais523: I think "join :: IO (IO a) -> IO a" may be clarifying, then, since you can use fmap/return/join instead of return/(>>=) 19:34:35 But of course there is more than >>= since there is also fmap, join, <$>, <*>, and so on 19:34:44 elliott_: even people who can get behind the paywalls, it's heavily DRMed 19:34:56 so I'm not entirely sure copying the resulting file would work, although it probably would to some extent 19:34:59 ais523: i.e., "if you have an IO program that produces another IO program that produces an a, then you can turn that into an IO program that produces an a (by just executing the program you get out of it)" 19:35:14 ais523: also, I'm pretty sure it would, since people regularly get pdfs behind paywalls for others... 19:35:24 oh, never mind, foudn it 19:35:25 found it 19:35:33 my guess is you'd be able to read it, but need a hacked PDF reader to be able to do anything but read it 19:35:42 perhaps it'd allow printing, if you were lucky 19:35:46 ais523: "hacked"? lol! 19:35:51 ais523: you realise that no pdf reader apart from like 19:35:53 acrobat and xpdf 19:36:00 actually obey the drm bullshit 19:36:00 respects the DRM? 19:36:14 Retype it if you need to... 19:36:18 elliott_: in that case, they're illegal in the US, or some such nonsense 19:36:29 ais523: I doubt that very much 19:37:08 the DMCA is kind-of ridiculous 19:37:15 it's much the same thing as libdvdcss, just on a smaller scale 19:37:39 (in that instead of heavy encryption, it's just a note saying "please") 19:37:39 anyway, can anyone here get behind ACM paywalls who isn't too legalistic to share the spoils? 19:37:59 I have several friends in university who probably have access. 19:38:03 Sgeo: updersation between itidus21, Vorpal, and kallisdeet <-- what? 19:38:05 ais523: you should delete evince, it's clearly illegal :) 19:38:09 Phantom_Hoover: Dude, I just linked you to the pdf. 19:38:18 Yes, it was a general thing. 19:38:22 elliott_: this sort of thing is why I refuse to go to the US :) 19:38:42 ais523: I'm sure we have something draconian enough to outlaw it 19:38:42 also, why I didn't take any sort of computer with me to Canada, although that was at least just as much a distrust of airports 19:39:22 I spent a week without Internet access there (except for a few minutes when I sneaked onto one of the computers the lecture hall used for projecting stuff on the screen; an old trick) 19:39:31 heh 19:39:42 without even usable phone, either, mobile or landline 19:40:09 (there were payphones, but they took around 5 minutes to calculate the cost of a call to the UK, and then quoted an amount so large it'd have been really awkward to pay using coins) 19:42:28 OK, ais523 has to hear my terrible idea now because it'll either help me forget about it, or reassure me that I'm not the only one suffering 19:42:44 elliott_: you have found your own Feather :) 19:43:16 ais523: a simple POSIX-alike where everything is run in ring 0 with @-style techniques; memory access requires checking that it's owned by the process 19:43:34 enforced how? 19:43:41 a ring 0 process could trivially change the perms 19:43:48 I /think/ it would end up more efficient than traditional implementations, because a branch per RAM access is cheaper than the syscall overhead 19:43:49 oh, statically 19:44:02 ais523: yep; although I was also considering if hardware virtualisation stuff could do it 19:44:03 you verify that the program is itself doing access checks on itself 19:44:05 since that's ubiquitous nowadays 19:44:08 and don't run it if it doesn't 19:44:13 that feels strangely evil 19:44:18 ais523: well, I was just going to make a C compiler do it 19:44:24 and have it be trusted 19:44:29 but checking the binary would be viable, too 19:44:32 yes, but what it does to the poor binary is beautifully ridiculous 19:44:47 it'd be the age of lawful programs 19:44:56 don't do anything without checking it's legal first, even though they /could/ 19:45:01 ais523: oh, and if the compiler is trusted that lets it optimise out certain checks 19:45:09 indeed 19:45:18 e.g. a = malloc(...); if (a) { ... *a ... } -- you don't need to check a afterwards 19:45:21 in the block 19:45:23 that sounds like a recipe for exploiting compiler bugs 19:45:28 ais523: yes, indeed 19:45:35 ais523: compiler bugs can already lead to exploits, though 19:45:42 if a daemon running as root is miscompiled 19:45:44 again, indeed 19:46:04 probably less likely to be exploitable on average, but it's still a qualititative difference 19:46:14 anyway, I'm tempted to do this because it sounds easier than @, and would be a neat proof-of-concept that some of its low-level details do increase efficiency 19:46:36 hmm, I remember the paper that found that if a processor got even a single multiplication wrong, it would be possible to crack some sort of encryption (I forget what) done on it 19:46:36 and ofc with @ the risk for compiler bugs is reduced since it's not based on "checks" for safety, but safety-by-design using the object capability model and the type system 19:46:42 heh, neat 19:46:43 brb 19:46:44 There is no statement of there ever being any male Sheikah since the true gender of Sheik is debated by many fans. 19:46:47 assuming you can get it to encrypt arbitrary text for you, or something like that 19:46:50 s/fans/slash fiction writers/ 19:47:14 kallisti: I think it's mostly an issue of semantics 19:47:21 -!- zzo38 has quit (Quit: zzo38). 19:47:43 this reminds me of the argument over Metroid Prime's gender (he, she, it are all viable options with plausible arguments makeable for them; plot-wise, it doesn't matter in the least) 19:47:55 the thing about Sheik though 19:47:59 is that Sheik is Zelda 19:48:00 and, by extension, Dark Samus' 19:48:13 and it doesn't explicitly mention anything about Sheik actually being male 19:48:14 so 19:48:18 kallisti: I'd be very surprised if that prevented people writing Sheik/Zelda slashfic 19:48:19 I would just kind of assume 19:48:32 that Sheik is a female, like Zelda, since they're the same person 19:48:37 Sheik was deliberately made with a male 3D model 19:48:46 but that was to keep the Sheik=Zelda thing secret from the player until right at the end of the game 19:48:48 sure MAGICAL GENDER CHANGING is possible but... not mentioned so not canon. 19:49:11 I think the most plausible argument is that Zelda is just very good at disguising herself, even if it includes cross-dressing 19:49:25 basically I think some people just want Sheik to have a penis. 19:49:39 * kallisti nods. 19:50:21 or like, they played the game thinking Sheik was a male and then when it was revealed they.... resisted changing their mind or something? 19:50:38 perhaps 19:51:29 though you could argue that there may be magic involved, since sheik has different eye color (red, like a Sheikah) 19:51:41 maybe Zelda just has some awesome contacts though. 19:51:50 you know what's fun? speculation about video game characters. 19:51:54 so fun. 19:55:17 kallisti, magic being involved is uncontroversial. 19:55:51 Conservation of volume is presumably still conserved under normal circumstances, no matter how many bandages you use. 19:56:14 -!- calamari has quit (Quit: Leaving). 20:01:27 back; disappointed not to see "biarb" from ais523 20:02:10 kallisti: I find it odd to posit that magic is used for changing eye-colour but to consider it unreasonable to posit that magic was used to change a far more drastic change in bodily structure (note: I have never played a Zelda game for long) 20:02:26 ofc, this is unrelated to the question of gender 20:03:41 does anyone know much about AMD-V / Intel VT-x? 20:12:43 elliott_: in Zelda games, magic exists but mostly only has a few defined effects 20:12:53 ais523: is changing eye-colour one of them? 20:12:56 no 20:13:07 but Zelda seems capable of unusual magical abilities 20:13:16 then my point stands :P 20:13:22 so who knows what magic she can do 20:13:32 I'm wondering if she was just using coloured contact lenses, though 20:14:37 thing it's hard to find information on: whether you can do hardware virtualisation in ring 0 20:14:42 as in, the code being virtualised runs in ring 0 20:15:30 ah, yes 20:15:34 that's what hardware virtualisation is for, it seems 20:20:29 ais523: hmm, I think what I'm doing is something like Xen, but where each program is an OS 20:20:40 and runs without a kernel 20:21:16 this sounds like decent practice for @ 20:21:55 ais523: yes, the only problem is that (a) I don't have a machine with the virtualisation stuff I need (b) it's literally all about low-level hardware details :) 20:23:01 elliott_: I'm not sure if I should advise you to put @ off, or complete it now before you end up getting a job and not having time for that sort of large project 20:23:29 ais523: clearly the only solution is to have someone pay me to work on @ 20:23:51 actually, I should write all but one line of @ while it's still in my head, and then write the last line whenever I need a Ph.D. handy :D 20:24:42 elliott_: you can actually get a PhD entirely on work you've already done 20:24:49 just, you're unlikely to get funded in that situation 20:25:03 heh 20:25:17 I think the main problem is that I'd have to write a book justifying @ 20:25:23 actually, I've probably already done that in here 20:25:59 the main problem is finding all the previous work on mildly related things 20:26:07 to show how a) you were inspired by it, and b) it's different from what you're doing 20:26:33 ais523: I'm kind of already doing that by digging up everything related I can find to take inspiration from it :P 20:26:46 elliott_: keep a record of it, then 20:26:53 that's the boring part :( 20:26:53 citation details, at least 20:27:02 but I probably should at least have a bookmark folder or something 20:27:06 nah, less boring doing it at the time when it's easy, then later when it takes a lot longer 20:27:07 since I keep losing things 20:27:14 ais523: s/then/than/, presumably 20:27:17 err, yes 20:27:22 grabbing citation details is quick and easy 20:27:33 formatting them for consistency is the boring part, but that can easily be done much later 20:28:06 ais523: ooh, I know, I'll just do @ now, and then my Ph.D. can be /naming/ it 20:28:22 lots of graphs and statistics on the emotional response to various potential names 20:28:22 hahahaha 20:28:33 then it'd, umm, be a PhD in marketing 20:28:45 which would be a bizarre thing for you to have 20:28:58 ais523: no, I'd, er, develop a New Kind of Name Generation Algorithm 20:29:04 that only works on @, for some reason 20:29:28 elliott_: spambot-based naming? 20:29:39 perfect @ name generator algorithm that only works on @: get_current_os_name() 20:31:02 but it only works on @ /after it's named/ 20:31:13 ais523: it's not @ until it's named! 20:31:38 wow, will this conversation look weird once @ /is/ named and we search-and-replace the logs 20:33:08 -!- GreaseMonkey has joined. 20:33:39 ais523: ooh, now i really hope Gregor does tha 20:33:39 t 20:33:53 and clog's owners too? 20:34:09 ais523: clog will probably turn to rust before then 20:34:22 but the logs will probably be backed up 20:34:24 also, can IRC bots rust? 20:34:40 if any IRC bot can, clog can 20:35:28 it'll just eventually clog up 20:35:33 /kick oerjan 20:36:33 how rude 20:37:06 @ elliott_ You can't rewrite history! 20:37:19 My name is indeed @ elliott_. 20:37:21 @ ais523 I'm just going to start Twitter-addressing everybody. 20:37:24 I changed it after the completion of @ to honour it. 20:37:38 shachaf: that's not twitter-addressing, you need to omit the space, and also replace @ with an at sign 20:37:52 elliott_: With a what? 20:38:06 I don't know if I have it on my keyboard; you should type it so I can copy it. 20:38:33 ＠ 20:39:07 shachaf: \@ 20:39:13 (thankfully, the regexp will take escapes into account) 20:39:54 You could've picked a less common character... 20:41:14 shachaf: 20:41:15 [elliott@dinky esoteric]$ fgrep '\@' ????-??-??.txt | wc -l 20:41:15 26 20:41:50 I mean, less common than '@'. 20:42:01 `run fgrep '\@' ????-??-??.txt | wc -l 20:42:04 fgrep: ????-??-??.txt: No such file or directory \ 0 20:42:08 shachaf: @ is the only thing that's right for it 20:42:09 wait, I need to change the directory 20:42:11 everything else looks wrong 20:42:13 `run fgrep '\@' logs/????-??-??.txt | wc -l 20:42:16 fgrep: logs/????-??-??.txt: No such file or directory \ 0 20:42:20 `run fgrep '\@' /var/irclogs/_esoteric/????-??-??.txt | wc -l 20:42:20 `ls 20:42:25 aha, that's where it is? 20:42:39 31 20:42:44 bin \ canary \ karma \ lib \ paste \ quotes \ share \ wisdom 20:42:59 `ls -F 20:43:01 bin/ \ canary \ karma \ lib/ \ paste/ \ quotes \ share/ \ wisdom/ 20:43:48 `? shachaf 20:43:50 shachaf? ¯\(°_o)/¯ 20:43:56 NOOOOOOO 20:43:57 `help 20:43:58 Runs arbitrary code in GNU/Linux. Type "`", or "`run " for full shell commands. "`fetch " downloads files. Files saved to $PWD are persistent, and $PWD/bin is in $PATH. $PWD is a mercurial repository, "`revert " can be used to revert to a revision. See http://codu.org/projects/hackbot/fshg/ 20:44:20 `run hg diff 1170 1171 20:44:24 1170: No such file or directory \ 1171: No such file or directory 20:44:28 `run hg diff -r 1170 -r 1171 20:44:31 diff -r 0d97b97d3636 -r 1cc5d9c44760 wisdom/shachaf \ --- a/wisdom/shachaf.Sat Nov 26 18:17:45 2011 +0000 \ +++ /dev/null.Thu Jan 01 00:00:00 1970 +0000 \ @@ -1,1 +0,0 @@ \ -shachaf mad 20:44:42 `run hg diff -r 1170 -r 1171 | patch 20:44:45 The next patch would delete the file shachaf, \ which does not exist! Assume -R? [n] \ Apply anyway? [n] \ Skipping patch. \ 1 out of 1 hunk ignored 20:44:49 `run hg diff -r 1170 -r 1171 | patch -R 20:44:52 patching file shachaf 20:44:59 `ls wisdom 20:45:01 `run mv shachaf wisdom 20:45:02 ​? \ ais523 \ augur \ banach-tarski \ c \ cakeprophet \ category \ elliott \ everyone \ finland \ finns \ fizzie \ flower \ friendship \ functor \ fungot \ gregor \ hackego \ haskell \ ievan \ intercal \ itidus20 \ kallisti \ mad \ monad \ monads \ monoid \ monqy \ nooga \ oerjan \ oklopol \ phantom__hoover \ phantom_hoover \ php \ qdb \ qdbformat \ quine \ sgeo \ u \ vorpal \ welcome \ wiki \ you 20:45:03 No output. 20:45:11 `? shachaf 20:45:14 shachaf mad 20:45:21 Well. 20:45:33 * shachaf is flattered that you went to all that trouble. 20:45:34 `rm wisdom/shachaf 20:45:36 No output. 20:45:37 why not just re-add it by hand? 20:45:51 it'd probably have been simpler 20:45:56 `? banach-tarski 20:45:58 ​"Banach-Tarski" is an anagram of "Banach-Tarski Banach-Tarski". 20:46:07 oerjan added that 20:46:09 I cannot be blamed 20:46:12 `revert 20:46:13 Done. 20:46:14 it's a good one 20:46:31 elliott_: don't you need to revert 2? or does it just revert the last side-effecting command? 20:46:34 `? shachaf 20:46:36 shachaf mad 20:46:40 ah, the latter 20:46:43 ais523: only mutating commands commit 20:46:52 `? c 20:46:54 C is the language of��V�>WIד�.��Segmentation fault 20:46:54 elliott_, like `quote ? 20:47:03 Vorpal: not any more 20:47:09 `rm wisdom/shachaf 20:47:11 No output. 20:47:12 `hg commit 20:47:12 `revert 20:47:13 elliott_, oh? Why did you remove that feature? 20:47:15 abort: could not lock working directory of /hackenv: Read-only file system 20:47:19 `? you 20:47:22 Vorpal: because it'd mess up transactional hackego :) 20:47:22 you a haskell 20:47:26 * shachaf has no idea how to use hg. 20:47:29 Done. 20:47:41 `rm wisdom/shachaf 20:47:41 `? u 20:47:43 No output. 20:47:45 `revert 20:47:45 shachaf, stop it 20:47:47 Done. 20:47:56 You stop it! 20:47:56 u monad? 20:48:07 `cat bin/revert 20:48:09 cat: bin/revert: No such file or directory 20:48:13 How is HackEgo talking withotu commands? 20:48:13 `rm wisdom/shachaf 20:48:15 No output. 20:48:24 shachaf, at least two people want to keep it. Me and elliott. That means a majority of us three. 20:48:36 It's okay, he can have it deleted. 20:48:40 Vorpal: I have extra votes because I'm me. 20:48:53 elliott_, you just did that to annoy me. Good job :P 20:49:03 shachaf: but kallisti has extra votes because he's Bjorn 20:49:26 `help 20:49:28 Runs arbitrary code in GNU/Linux. Type "`", or "`run " for full shell commands. "`fetch " downloads files. Files saved to $PWD are persistent, and $PWD/bin is in $PATH. $PWD is a mercurial repository, "`revert " can be used to revert to a revision. See http://codu.org/projects/hackbot/fshg/ 20:49:32 Vorpal: The only reason you wanted to keep it was that elliott_ wanted it. 20:49:39 elliott_: You should get rid of the _. 20:49:45 It's grating on the fingers, you know. 20:49:45 shachaf, come on. We two usually never agree on /anything/ 20:49:58 Vorpal: Unless annoying a third party is at stake! 20:50:10 shachaf, not really no 20:50:27 shachaf: wait, you're annoying? I hadn't realised 20:50:35 X-D 20:50:41 Yes, shachaf is super annoy(ing|ed). 20:50:59 I hadn't either. 20:52:08 Yeah, I was buying cell-batteries the other day and the retailer wanted me to enter a facebook user and password so it could automatically insert a facebook comment that I had purchased batteries from them. 20:52:37 gah, my mind cannot comprehend the amount of stupidity in existence implied by that comment 20:52:44 (not from the author, he clearly couldn't either) 20:53:23 ais523: if it makes money, it's not stupidity 20:53:29 wow 20:53:40 elliott_: I'm not convinced it's stupid from the retailers' point of view either 20:53:55 but for it to be sensible from their point of view, implies a sufficient number of stupid people around that it actually makes a profit 20:54:59 ais523, it could be an experiment to find out if that is the case? 20:55:00 ais523: well, it's not necessarily stupid to prioritise not being bothered by a retailer over very minorly annoying some people, considering how much noise facebook has anyway 20:55:05 hopefully it is not the case 20:55:32 elliott_: it /is/ stupid to give a username and password that you probably use for everything to a random retailer, though 20:56:15 ais523: well, OK, but I'd rather blame (a) the username/password model to start with and (b) the lack of proper computer security education, although (b) is massively impaired by the fact that the current systems are unusable (see (a)) 20:56:39 what model would be better than username/password, and also that people could be persuaded to use? 20:56:44 and there are situations where you have to give away your password; for instance, when trying to get my MacBook replaced, Apple demanded my password 20:56:53 which doesn't exactly educate people not to give their passwords away 20:57:11 elliott_: err, what? that seems like a bizarre thing for them to want 20:57:22 is that the login password to unlock the computer for the main user? 20:57:24 ais523: I tried notto think too much about it 20:57:29 and no, my Apple ID password 20:57:31 over the phone 20:57:35 ... 20:57:37 what 20:57:42 ah, OK, probably to verify that you're an actual customer of theirs 20:57:53 yes, something like that 20:57:58 a password to log in to the person at the other end of the phone is reasonable 20:58:07 no obvious reason why they should be restricted to computers 20:58:15 yes, but it's still giving your password to someone else, so it's hardly surprising that people aren't averse to doing that 20:58:20 other than salting/hashing being hard to do mentally 20:58:33 ais523, hardware certificates + password entered on the hardware certificate device use to sign a response code. That should be better than classical user/password. Major PITA for anything except bank transactions and other high security stuff 20:58:35 (actually, salting is easy) 20:58:49 a password existing for the purpose of giving to specific other people is reasonable to give to those people 20:58:55 ais523: anyway, I don't know which model is necessarily better than passwords, but things like OpenID are a start, even if they have a password at the base of it; public key crypto is also promising 20:59:32 elliott_, hardware certificates :P 20:59:42 Vorpal: a GPG key on a USB key integrated into your browser that asks for the passphrase when it's plugged in doesn't seem that bad to me 20:59:54 especially if the USB key doesn't expose the GPG key but just signs things as it 20:59:58 elliott_, I was thinking along the lines of smartcard but sure 21:00:11 elliott_: in that case, you can put a fingerprint reader on the USB device 21:00:25 ais523: everything i've read suggests fingerprint readers are completely insecure 21:00:27 probably saves time over password memorisation, and you still have two factors 21:00:42 elliott_: right, the problem is that they're too easily brute-forced 21:00:47 fingerprint readers are insecure yeah 21:00:49 ais523: and copiable, I believe? 21:00:53 but someone would probably notice brute-forcing in a shop 21:00:58 you want an iris scanner! 21:01:12 ais523: true, but nobody wants an authentication mechanism that only works in shops 21:01:18 ah, OK 21:01:31 all biometrics are copiable for the same reason that all videos are copiable 21:01:38 they have to be translated to data at some point, and you can copy that 21:01:51 ais523, fingerprints are easy to copy however iirc 21:01:51 ais523: in a shop, something like logging in on a smartphone and passing an authentication to post a status update wirelessly seems like the most reasonable way to do something like this (not that it /should/ be done) 21:01:53 and just use it directly rather than scanning it in 21:02:12 that way, the shop can't do anything at all apart from post one status update right then 21:02:15 elliott_: hmm, perhaps the shop should have a QR code, and the smartphone scans that 21:02:23 it probably knows the Facebook username/password already 21:02:25 ais523, like if you have a laser printer + some stuff that is easy to get your hands on for not a lot of money you can copy a fingerprint 21:02:30 heh; I gather that QR codes aren't gaining traction because they're really ugly,t hough 21:02:33 *, though 21:02:34 forgot the exact details 21:02:37 you'd probably have to accept an authorisation popup first time 21:02:42 elliott_: also, because they seem to have too much computational power 21:02:47 really? 21:02:49 I heard a rumour of QR code trojans a while back 21:02:50 elliott_, they are gaining traction here in Sweden, slowly. 21:02:57 but I have no idea what level of social engineering that required to work 21:03:06 Vorpal: they might be a growing fad, but that doesn't mean they're gaining long-term traction 21:03:09 ais523: wow 21:03:12 well sure 21:03:19 ais523: they only encode a small bit of textual data to my knowledge, so that's surprising 21:03:24 it might have been as simple as "QR code points at website containing malicious software download" 21:03:55 probably was, actually, and the media went crazy about it as usual 21:04:06 definitely the former 21:04:11 qr codes just encode data 21:04:28 don't listen to mainstream media wrt viruses. They are bloody useless. 21:05:04 Vorpal: s/viruses/computers/ 21:05:16 s/computers/anything/ (per Knoll's Law) 21:05:25 *Law of Media Accuracy 21:05:41 Vorpal: well, this was tech media 21:05:45 but they can be just as bad sometimes 21:05:51 they just sound more like they know what they were doing 21:06:21 elliott_, true 21:06:30 ais523, heh 21:06:36 ais523: that's why you stick to respected institutions like The Register! 21:06:53 elliott_: at least the Register is reasonably consistently biased 21:07:02 (it has a strong pro-Paris-Hiltion bias) 21:07:02 heh 21:07:18 wat 21:07:37 -!- oerjan has quit (Quit: Good night). 21:07:43 Vorpal: do you know anything about x86 hardware virtualisation 21:08:20 elliott_, yes 21:08:25 elliott_, not much though 21:08:31 elliott_, why? 21:08:52 Vorpal: well, I know it can be used to virtualise code running in ring 0 21:08:59 presumably it can be used to remap memory accesses by that code? 21:08:59 yes and? 21:09:04 hm 21:09:06 I know it can remap memory accesses by virtualised stuff in ring-3 21:09:33 elliott_, no idea. Probably depends on if it is hardware stuff, in which case you need an IOMMU, which is not yet common on consumer (read: non-server) hardware 21:09:43 hmm 21:09:45 as in DMA or such 21:09:45 http://en.wikipedia.org/wiki/Extended_Page_Table 21:09:48 I think this will work 21:09:55 "A separate set of page tables (the EPT tables) translate from guest-physical addresses to the host-physical addresses that are used to access memory." 21:10:03 elliott_, sure 21:10:07 elliott_, what about it? 21:10:11 and why do you want it 21:10:13 well, it'll let me remap the memory 21:10:17 of ring-0 stuff being virtualised 21:10:26 why are you virtualizing ring-0 stuff? 21:10:28 only Nehalem-onwards, but oh well 21:10:32 and looks like AMD implements the same thing 21:10:42 elliott_, you want to use kvm. Because AMD and Intel use different models for it 21:10:45 kvm abstracts that 21:10:49 Vorpal: no, I don't 21:10:55 oh? 21:11:16 it's an OS ide I've had that is both significantly easier to do than @, and demonstrates/tests some of its low-level performance benefits 21:11:17 *idea 21:11:32 basically, it's a POSIX-ish kernel that runs everything in ring 0 that virtualises every process 21:11:36 (for security) 21:11:44 heh 21:11:49 but yeah 21:11:53 my desktop can run that 21:12:03 elliott_, I think virtualbox has it as a "nested page table" thingy 21:12:05 hmm, although, I'm not sure how expensive ring 0 stuff talking to the virtualisation code is 21:12:22 elliott_, without that feature you just handle those page tables in you hypervisor software 21:12:24 if it's as expensive as a syscall, then my adventage is lost 21:12:39 elliott_, might be more expensive 21:12:39 so if anyone knows the answer... let me know 21:12:47 wouldn't surprise me 21:12:55 Vorpal: well, not much more expensive, at least, or Xen would be really slow 21:13:03 Vorpal: ISTR that running Linux under Xen is actually faster than running it natively 21:13:05 in certain scenarios 21:13:13 heh 21:13:24 I really want to see a citation on that 21:13:36 don't have one, I'm afraid 21:13:51 elliott_, anyway linux has special code to run better as a guest 21:13:52 Vorpal: anyway, even if virtualisation isn't possible the OS idea will still work... I'll just go back to my original idea of building the checks into the compiled code 21:14:21 because I think a branch on every memory access will pay itself off by the vastly reduced syscall overhead 21:16:11 ais523: OK, your new job (changed from discouraging me to write this) is to make sure I continue writing it after I get a bootloader 21:16:18 I really like writing bootloaders 21:16:28 haha 21:17:37 one of the main problems with @ is that it's not at all clear where it actually starts running 21:18:36 presumably you have some outside-@ bootloader that just sets up for bits of disk to be swapped into memory so they can start running again 21:20:32 ais523: and then jumps where? 21:20:52 to where the IP was the last time stuff got flushed to disk 21:20:53 -!- sebbu2 has changed nick to sebbu. 21:20:55 which should be very recent 21:21:15 in fact, it's going to be in the disk-flushing routines, which makes life rather easier 21:21:19 ais523: there's more than one IP, and there's more machine state than just RAM + registers 21:21:40 ais523: anyway, that doesn't work, because you need to set up more than that 21:21:44 timers, interrupts, and so on 21:21:47 elliott_: well, it jumps to stuff to restore that, then to where stuff was 21:21:56 the problem may be difficult, but it's easy to describe 21:21:56 (the IP of the disk-flushing stuff won't be stored) 21:22:06 (because it's run from a timer, and doesn't block anything) 21:22:13 (well, it does blockt hings, but not /everything/) 21:22:18 (it just causes a switch to another thread, mostly) 21:22:39 ais523: right, but where is that stuff? :) 21:22:52 for proper orthogonal persistence, it has to be persisted 21:23:28 alternatively, you could decide that some of it can't meaningfully be persisted (network driver state, for instance), in which case it'd be the driver's job to initialise it 21:23:44 basically, look at what Linux does on hibernate/unhibernate; it's basically that 21:23:57 I know that much, but Linux unhibernate is too specialised 21:24:03 because it assumes all the structures and the like are the same 21:24:09 because I think a branch on every memory access will pay itself off by the vastly reduced syscall overhead <-- depends on how IO-bound the code is. 21:24:11 @ can't assume that, it needs to have a completely generic bootloader 21:24:19 for IO you traditionally need lots of syscalls 21:24:21 Vorpal: I disagree 21:24:36 Vorpal: even CPU-bound tasks that do, e.g. concurrency of any sort, have to do communication 21:24:49 elliott_: it's not the bootloader's job to do most of the unhibernate 21:25:02 ais523: then whose job /is/ it, and how does the bootloader get to it? 21:25:22 also, wrt the other conversation, concurrency primitives don't touch the kernel except when there's contention, nowadays 21:25:31 elliott_, I'm considering the sort of heavy task I personally do a lot of. Which is stuff like optimising non-linear equations over thousands of data points for best fit. 21:25:37 elliott_: it's the init scripts' job, IIRC 21:25:39 also, wrt the other conversation, concurrency primitives don't touch the kernel except when there's contention, nowadays 21:25:41 pure number crunching 21:25:44 ais523: yes, because syscalls are slow 21:25:45 I can't remember if they're run by init directly during unhibernate, or some other way 21:25:49 and so removing syscall overhead sped things up 21:25:50 elliott_: exactly 21:26:04 but the point is, there isn't currently syscall overhead in that because it was removed a different way 21:26:16 elliott_, avoiding checks on memory access by being smart in the compiler will certainly pay off for some tasks though 21:26:17 Vorpal: "tight loop of number crunching with a data set that fits into RAM and absolutely no concurrency whatsoever" is rare and becoming even rarer as multicore gets more and more ubiquitous 21:26:25 so the issue is about how syscall-bound the program is 21:26:37 Vorpal: for a job like that, anyway, a /scheduler/ is a bottleneck 21:26:39 Web of Lies gives you a really good idea of how syscall-bound a program is 21:26:46 and if you're not calling any syscalls, why not run it directly on bare hardware? 21:26:48 as it has no timing effect on anything but syscalls 21:26:52 elliott_, well yes. 21:26:53 so OSes are already working against tasks like that 21:27:00 nobody will care if they work against them a bit more 21:27:13 elliott_: I've actually been wondering how @'s scheduler works, or if it has one, and if it doesn't have one what it does instead 21:27:25 and if you're not calling any syscalls, why not run it directly on bare hardware? <-- because it is less convenient when debugging :P 21:27:55 and usually you do some syscalls even in those cases. Load initial data set, write out final result 21:28:00 at the very least 21:28:04 indeed 21:28:15 so reducing sysccall overhead helps there 21:28:18 so that is like 3 syscalls minimum, one read, one write, one exit 21:28:22 probably a few more 21:28:26 probably not as much as you lose, but it's likely that you do a bunch of read and writes 21:28:33 because a lot of datasets can't fit into RAM 21:28:40 at least, the datasets where you /really/ care about performance do 21:28:51 because a small change in constant factors has a large change on the end result due to the size of the data 21:28:56 elliott_, the thing about those syscalls in this case is that they are one-time. They don't really vary that much between data sets of different sizes either. It is still a single read and a single write 21:29:02 Vorpal: see above 21:29:02 ais523: that's something I've been thinking about a lot recently 21:29:10 ais523: it definitely does have a scheduler 21:29:21 elliott_, if your data set can't fit into your ram things are going to be horribly slow anyway 21:29:23 -!- Patashu has joined. 21:29:39 elliott_, even without considering IO overhead disks are way slower than ram 21:29:47 Vorpal: Most data sets don't fit in RAM. 21:29:50 Vorpal: not really, if you can do it in chunks of 8 gigs or so at a time... 21:29:56 At least, most data sets you give a shit about. 21:29:59 assuming there's not too much interdependency 21:30:05 pikhq_, indeed. 21:30:19 ais523: and, problematically, it needs a /really good/ scheduler 21:30:36 In a land where heavy computing jobs go through a terabyte drive in a day, everything is IO bound. 21:30:37 elliott_: with the caps to do anything 21:30:39 anyway my /personal/ use case here is mostly stuff that fits into ram. Like 5-6 GB of data. 21:30:41 ais523: and it needs to handle millions of tasks (= processes/threads) running 21:30:54 ais523: oh, it's not a problem for such low-level code to have all permissions 21:30:58 well, OK 21:31:00 although it doesn't need quite that many 21:31:22 elliott_: it needs to be able to stick the IP in the middle of arbitrary code 21:31:28 ais523: basically I need tasks to be as cheap as lightweight threads in GHC(/Erlang/whatever) 21:31:57 there's no real problem with a million-task scheduler with current technology; the issue is more adapting for various patterns of blocked/nonblocked 21:31:59 yeah erlang have really light weight processes 21:32:08 iirc ~300 words per thread + stack 21:32:08 Vorpal: not as lightweight as GHC, to my knowledge 21:32:21 at least speed-wise 21:32:22 for handling operations like sleep, etc, you aren't going to do better than n log n (possible with a heap-like priority queue) 21:32:28 is that going to be good enough? 21:32:30 elliott_, quite possible 21:32:32 ais523: well, the problem is more memory usage 21:32:48 ais523: I need some subdivision of the massive heap to do effective GC 21:32:52 just throw in more RAM. that is where computers are heading anyway 21:32:57 ais523: I want to be able to do copying, incremental GC 21:33:04 elliott_: is the scheduler doing that? 21:33:05 ais523: tasks seem a reasonable unit to do that at 21:33:07 elliott_, can't you have per-process heap for stuff not likely to be sent between threads? 21:33:07 ais523: no 21:33:10 ais523: but the point is, how do you divide it? 21:33:16 there's no concept of "process" 21:33:19 Vorpal: there's no concept of "process" 21:33:20 elliott_, per task then 21:33:24 Vorpal: that's the problem 21:33:31 I assume there is a concept of "unlikely to be sent to a different task", but it'd be quite hard to determine 21:33:42 elliott_, or per unit that can be stopped independently from other units for GC tasks 21:33:43 my memory management strategy involved 2 mebioctets + 4 kibioctets per pool 21:33:47 in pages 21:33:50 I suppose you could just use the generational GC approach, treating all data as that until it's actually sent to another task 21:33:51 that's not viable for millions of threads 21:34:01 hm 21:34:03 2 megs * 1 million = 2 terabytes 21:34:05 whoopsie! 21:34:12 elliott_, do you need to split on whole pages? 21:34:13 (and this has to be in /RAM/, not on disk) 21:34:14 elliott_: why not? just use a system where the address space is way bigger than the actual amount of memory 21:34:20 ais523: in /pages/ 21:34:23 although, x64 probably doesn't meet that requirement 21:34:25 that map to /physical RAM/ 21:34:27 elliott_, afaik erlang does not use a whole page per process 21:34:32 elliott_: oh, physical, ouch 21:34:39 Vorpal: well, that was my memory management trick, to make an allocation take 2 cycles 21:34:43 and no branches 21:34:51 for allocations of less than 4 kilobytes 21:34:53 elliott_, ... that might not be a good tradeoff 21:34:54 (= almost all of them) 21:35:06 Vorpal: it's an excellent tradeoff, it just means I can't have a pool per task 21:35:18 which brings up the question, how /do/ I divide pools? 21:35:18 hm 21:35:31 note: two CPUs cannot allocate from the same pool at once 21:35:34 and I don't want to use locks 21:35:43 so I can't just say "oh, divide it between 100 tasks" 21:35:56 because those tasks will have vastly reduced concurrency 21:36:00 a pool per cpu? 21:36:18 or core or whatever 21:36:25 Vorpal: a CPU isn't really anything; this has to be of the real heap, which is of ~a terabyte in size 21:36:27 not RAM itself 21:36:31 because GC is done on the real heap 21:36:41 elliott_, I don't see any reason why all the allocations of a single task have to come from the same pool 21:36:44 also 21:36:46 if it is moved to a different CPU 21:36:49 that would tie tasks to CPUs permanently 21:36:53 hm wait 21:36:55 cache lines 21:37:01 okay I see reasons 21:37:04 Vorpal: it's nothing to do with cache lines, but that's not what I said 21:37:13 the reason two CPUs can't use a pool is because there's a really nasty race condition 21:37:20 elliott_, you don't want to share a page between two CPUs unless it is actually shared data :P 21:37:22 that could only be solved with a lock or slower CAS shit 21:37:27 which defeats my 2 cycle allocation strategy 21:37:38 elliott_, when allocating yes. But not when /using/ said pages 21:37:48 that's what I said 21:37:50 if you allocated offset 40-57 in the page 21:37:51 but 21:37:55 you can use that freely 21:37:56 a program can allocate from its pool at any time 21:38:01 and a program only uses one pool at a time 21:38:05 (it's expanded when necessary) 21:38:08 (and is the unit of GC) 21:38:17 elliott_, I suggest tying the pool to the cpu instead. 21:38:21 but whatever 21:38:22 elliott_: hmm, how common are allocations? and how common would they be if they were very cheap? 21:38:24 Vorpal: I just told you that doesn't work at all 21:38:28 Vorpal: _there is no CPU_ 21:38:32 elliott_, I don't think your GC design is viable. 21:38:35 it is 21:38:42 you just don't understand it 21:38:44 not with millions of tasks 21:38:49 because you keep making references to "CPUs" and other things that don't exist 21:38:55 also, hmm, how do you verify that a process doesn't access out-of-address-space when it's allocating memory dynamically 21:39:02 Vorpal: I never said I want a pool per task 21:39:04 elliott_, what the fuck do you execute the damn code on then? 21:39:05 that's what I'm trying to avoid right now 21:39:08 pink creepers? 21:39:14 Vorpal: lol, you're an idiot 21:39:23 Vorpal: you cannot make reference to CPU in the distribution of pools 21:39:32 elliott_: CPU affinity is only meaningful wrt per-CPU cache, AFAICT 21:39:36 elliott_: Then your memory model does not handle NUMA. 21:39:39 elliott_, why? 21:39:43 pikhq_: w h a t 21:39:45 and possibly, in the future, per-CPU RAM that isn't cache, but that's not standard yet 21:39:50 and yes pikhq_ has a point 21:39:59 however, I'm not convinced that per-CPU cache is unimportant here 21:39:59 Vorpal: I've decided explaining to you won't make you any less stupid, so I'm just going to answer ais523 instead 21:40:00 NUMA? 21:40:05 elliott_: hmm, how common are allocations? and how common would they be if they were very cheap? 21:40:07 Non-Uniform Memory Access. 21:40:09 ais523: exceedingly common 21:40:11 Phantom_Hoover, Non-uniform memory access 21:40:13 like core i7 21:40:19 also, hmm, how do you verify that a process doesn't access out-of-address-space when it's allocating memory dynamically 21:40:21 ais523: hm? 21:40:22 at least with dual cpus (not cores) 21:40:44 elliott_: say a process writes the equivalent of char* a = malloc(5); putc(a[7]); 21:40:54 Wherein each CPU has its own memory (but can access that of others, though more slowly) 21:40:57 hmm, that's not a huge problem, you could just insist on bounds checks everywhere 21:41:03 and I think that'd be enough 21:41:11 ais523: it can't, and bounds checks aren't necessary 21:41:18 pikhq_, I believe nehalem and after is that, rihght? 21:41:20 right* 21:41:22 elliott_: umm, I mean char[], not char* 21:41:24 ais523: the whole point of @ is that it doesn't run untrusted code 21:41:36 Vorpal: For Intel, yeah. 21:41:38 elliott_: I know; the question is, how do you determine whether such code is trustworthy 21:41:40 pikhq_, yeah 21:41:45 ais523: umm, the capability model? come on 21:41:48 and the answer, AFAICT, involves bounds checks, either runtime or statically 21:41:52 pikhq_, I believe amd have on-cpu MMUs too? 21:41:55 ais523: if you can prove to the @lang compiler that you never access out of bounds, bounds checks can be omitted 21:41:56 pikhq_, since even longer 21:41:59 ais523: for instance, length-carrying vectors 21:42:02 didn't k8 introduce that? 21:42:05 elliott_: yep, indeed 21:42:09 that's what I meant by static bounds checks 21:42:09 there's no "checks" there, your program just doesn't type if it accesses things wrong 21:42:10 Yeah, AMD's been doing NUMA a long freaking time. 21:42:15 ais523: I typed that before you said it 21:42:16 I thought it was a problem, just realised it wasn't one 21:42:23 pikhq_, and elliott_ has no clue about it... 21:42:28 Vorpal: lol 21:42:39 8 years now. 21:42:42 Vorpal: stop being a fucking moron and assuming that because you don't understand how @'s GC works, I know nothing about NUMA 21:42:45 AMD Dragostea Din Tei? 21:42:55 copumpkin: lol 21:43:12 elliott_, well pikhq_ had a point about you needing to use a local pool if possible or suffer bad speed. 21:44:00 that's irrelevant, since processes point to the abstract memory space. 21:44:13 if necessary, the pool can be loaded into the RAM of the CPU it's running on. 21:44:17 hm 21:44:31 elliott_, but you said there was no such thing as a CPU :P 21:44:50 Vorpal: Insofar as virtual memory is concerned, there is no meaningful notion of "CPU". 21:44:56 Vorpal: because you kept trying to define pool allocation in terms of CPUs after I repeatedly told you that made no sense 21:45:01 pikhq_, well obviously 21:45:02 As the virtual memory space would be identical with 1 CPU or 1000. 21:45:03 summary of elliott_'s arguments: CPUs are not a program-visible concept, in the cases where they're relevant that's handled by the memory allocator or pager 21:45:12 ais523: not exactly 21:45:18 you can't tie pools to CPUs because 21:45:24 (a) that'd mean tasks would be permanently tied to one CPU 21:45:24 elliott_, I'm suggesting that as a way to avoid having as many pools *and avoid the race conditions* 21:45:32 (b) what the hell do you do for tasks on disk? 21:45:33 elliott_, it means a completely different GC model though 21:45:35 you GC disk too 21:45:37 in units of pools 21:45:45 it makes no sense at all 21:45:59 Vorpal: well thanks, that's a really unuseful suggestion and also not what you actually said? 21:46:10 (a) that'd mean tasks would be permanently tied to one CPU <-- no, the pool of the current cpu would be transparently used when allocating. 21:46:17 and you could access any pool 21:46:25 for stuff you already allocated 21:46:33 (b) what the hell do you do for tasks on disk? <-- hm? 21:46:34 my GC model works perfectly fine with a decent way to allocate tasks, which you have so far not offered a single idea for, so I'm going to assume that you just don't understand the model, since you haven't asked for it or demonstrated any knowledge of it 21:47:11 Vorpal: well thanks, that's a really unuseful suggestion and also not what you actually said? <-- it was exactly what I said 21:47:20 elliott_: I vote you have a certain number of pools (based on RAM or disk size?), and when a thread starts it gets assigned the least used pool. 21:47:28 "pool per cpu durrr" != " elliott_, I'm suggesting that as a way to avoid having as many pools *and avoid the race conditions*" 21:47:48 elliott_, then you misunderstood me 21:47:55 sigh 21:47:58 this is pointless 21:48:02 hmm, what's the reason for having more than one pool? I know it's a good one, but it'd probably make this clearer to have it spelt out 21:48:06 elliott_, pikhq_'s idea makes sense 21:48:12 elliott_, but you are likely going to ignore it 21:48:16 ais523: you can't do copying GC on a terabyte if you don't have another terabyte 21:48:34 Vorpal: i'm working on a response to him because he's not an insufferable shithead; you, on the other hand, are going on /ignore 21:48:42 fun fact: I can't type infinitely fast 21:49:00 ais523: Incremental GC. 21:49:09 pikhq_: that's not viable, since GC of a pool pauses every task using that pool, and two tasks on the same pool cannot ever be run at the same time (= on different SMP CPUs) 21:49:13 elliott_: hmm, OK; what's stopping you having half the memory as one pool, and the other half as the place it gets copied to? other than the wastefulness? 21:49:20 ais523: and you can hardly pause the entire OS while you GC an entire terabyte, either 21:49:24 that'd take an awfully long time 21:49:31 ah, right 21:49:42 ais523: well, that's wasteful, but even then, doing a single atomic copying-GC on a terabyte pool -- on disk! -- would be insanely slow 21:49:55 so, hmm, are you planning to go on a stop-and-copy architecture specifically? or some other sort of copying GC? 21:50:14 ais523: well, it'll be generational (pools will contain multiple generations, I think) 21:50:30 (and past a certain generation, they'll be dissociated from a pool entirely) 21:50:42 (so that really long-lived objects just sort of hang around on disk and are basically never touched by the GC) 21:50:59 elliott_: That sounds like the limits of having multiple tasks per pool. 21:51:13 pikhq_: hm? 21:51:14 And you already agreed that one pool per task isn't viable, so. 21:51:19 ais523: stop-and-copy seems the most viable strategy 21:51:32 ais523: although, it would be nice if you could have a tight loop with allocation that was guaranteed to never pause for long at all 21:51:51 ais523: so you could write things that really have to be realtimeish, e.g. small-buffer video/audio code 21:51:59 without having to avoid allocations (nearly impossible in @lang) 21:52:06 What you need is a scheme for assigning task to pool, and so I gave you a simple one and claimed it was impractical because, basically, it would involve multiple tasks in a pool. 21:52:42 Though: if you want to limit the stoppage, there's no reason for the pool assignment for a task to be *permanent*. 21:52:51 pikhq_, I gave him another scheme for the same thing and he claimed it was impractical too. This discussion is being pretty pointless 21:52:52 pikhq_: well, you need to assign them with some intelligence 21:53:12 pikhq_: e.g., a cluster of 10 threads that "work together" in some sense to serve some larger task that started them, are probably OK to put on the same pool 21:53:22 That's a fairly 'mundane' scheduling problem. 21:53:31 because they're "related", and so it doesn't matter if they don't run at the same time SMPly 21:53:41 You get similar issues with trying to stick related tasks in the same NUMA group. 21:53:45 mm 21:54:02 It's not exactly an *easy* problem, but it's at least a rather well-understood one, and not at all @-specific. 21:54:31 pikhq_: I wonder how fast I could get a concurrent allocator 21:54:47 I basically need an atomic form of {*y += n; x = *y;} 21:54:58 where x is a register and y is a memory location 21:56:18 Definitely CMPXCHG. 21:56:35 (x86's primary atomic instruction) 21:56:36 pikhq_, that might need retrying if it fails 21:56:46 isn't there an atomic increment? 21:56:52 Not sure if it returns the old value 21:56:55 pikhq_: I have a feeling it's not going to be quite as fast as MOV + ADD 21:56:57 or any value even 21:57:31 elliott_: It is if there's no contention. 21:57:58 hmm, I'm not sure how cmpxchg would work, because you need to do an increment, not just a swap with some predetermined value 21:58:02 so it'll need some lock layering on top 21:58:48 pikhq_, I presume elliott_ is actually ignoring me. But lock xadd might do the job 21:59:26 unless I misunderstood the docs 21:59:35 which definitely won't be as fast 21:59:44 elliott_: What you do is blithly fetch the value, increment it, and attempt the cmpxchg. If it fails, you restart. 21:59:45 elliott_, oh lock xadd will be 21:59:54 oh, ah 21:59:56 The thing is, you pass cmpxchg what the old value should be. 22:00:03 how cheap is cmpxchg with no contention? 22:00:11 pikhq_, I'm /pretty/ sure lock xadd will do this even cheaper. 22:00:12 pikhq_: oh, that's a problem 22:00:20 presumably, you branch to determine whether the cmpxchg worked or not? 22:00:21 pikhq_, you might want to inform elliott_ 22:00:29 the whole idea with my 2-cycle allocator is to avoid branches 22:00:57 Having a single branch that'll be predicted correctly almost always is not going to be notably worse. :) 22:01:09 oh looks like pikhq_ is ignoring as well 22:01:13 pikhq_: it is when it's something as common as this :P 22:01:24 pikhq_: and I'm not so sure it'll always be predicted correctly 22:01:38 ^say elliott I know the solution to this. There is a better atomic instruction. I told you above. 22:01:50 ^help 22:01:50 ^ ; ^def ; ^show [command]; lang=bf/ul, code=text/str:N; ^str 0-9 get/set/add [text]; ^style [style]; ^bool 22:01:50 allocation is really common, and probably follows very predictable patterns in @lang's generated code, so I would not be surprised if the contention rate was high for a pool 22:01:52 Vorpal: Is xadd atomic? 22:01:59 pikhq_, with the lock prefix 22:02:20 pikhq_, but you need that for anything to be atomic 22:02:34 Hmm, sure enough, that works better. 22:02:53 hmm, xadd? this looks like the right thing 22:02:53 pikhq_, don't tell elliott_ since he doesn't want to know what I have to say :P 22:03:21 the question is how much slower LOCK XADD is compared to ADD + MOV in a uniprocessor situation 22:03:34 probably not noticeably, but it'd be interesting to know exactly 22:03:53 you can trivially specialise the code on the fly 22:03:55 In a uniprocessor situation, it's "ADD + MOV + MOV". 22:04:03 and uniprocessors are kind of outdated anyway 22:04:36 pikhq_, isn't it xchg,add even? 22:04:39 pikhq_: hmm, I don't think xadd can do memory 22:04:42 0F C1/r XADD r/m32, r32 Exchange r32 and r/m32; load sum into r/m32. 22:04:46 oh, hmm, yes it can 22:04:55 If it couldn't it would be worthless. 22:04:58 right :) 22:05:15 "It's atomic because it accesses a per-thread resource!" 22:05:17 the fact that xadd has sparse google results is worrying, though 22:05:27 is it one of those CISCy instructions that nobody generates any more and so has really badly optimised microcode? :p 22:05:48 No, it's one of the basic atomic primitives. 22:06:14 http://www.xadd.net/ Why did someone buy a domain for this 22:06:16 what do you do when a pool is full anyway 22:06:31 Collect. 22:06:51 pikhq_, yeah but you need to reset the counter to be able to use this simple allocation stratergy 22:06:54 or even move data 22:06:59 Vorpal: accesses to it will go into the 4k barrier page space and thus cause a page fault 22:07:05 pikhq_, this simple scheme can't handle skipping holes after all 22:07:19 Vorpal: Moving GCs are not magic. 22:07:20 Vorpal: nor do modern GCs 22:07:27 everyone uses a pointer-bumping allocator these days 22:07:32 heh 22:07:33 they just do it with a branch 22:07:34 really? 22:07:39 interesting 22:07:42 Yeah, basically everyone but Boehm. 22:07:46 Vorpal: yes, which is why you allocate a new pool and compact as you move it there 22:07:51 And Boehm only doesn't because it needs to work with C. 22:07:52 by copying contiguously. 22:07:53 I thought the glibc allocator for example was extent based 22:07:56 http://www.xadd.net/ Why did someone buy a domain for this <-- I thought you were in favour of foldl.whatever? 22:08:00 Vorpal: glibc: "a garbage collector" 22:08:01 Vorpal: That's *not* a GC. 22:08:06 elliott_, well true, not the case 22:08:09 ais523: those were cute, this is just silly 22:08:27 also, TLDs are getting increasingly obnoxious to remember 22:08:34 if they were used for their original purposes, there wouldn't be a problem 22:08:41 but there isn't really a TLD for "novelty website" 22:08:46 heh 22:08:56 ais523: hey, I have a .net that's actually an internet service provider! 22:08:57 The TLD system is just very poorly suited to the modern 'net. 22:09:04 elliott_: wow 22:09:17 arguably something like Freenode can plausibly correctly be .net too 22:09:26 pikhq_, the ccTLDs kind of work still. Except for US. 22:09:34 ais523: admittedly, the service we provide is mainly a minecraft server 22:09:40 but that's an internet service that we're providing 22:09:42 haha 22:09:47 heh 22:09:48 and web hosts are considered ISPs, so I don't see why that shouldn't be 22:09:58 elliott_, they are!? 22:10:13 Vorpal: In a sense. They provide a service on the Internet. 22:10:13 http://en.wikipedia.org/wiki/Internet_service_provider 22:10:19 the technical meaning differs from the colloquial meaning 22:10:24 (which only means "an actual internet link provider") 22:10:29 pikhq_, well, that is not what people /usually/ mean by ISP 22:10:33 elliott_, quite 22:10:36 bah, that page has the wrong definition 22:10:36 Or "a provider of Internet service". 22:10:42 prescriptivists :) 22:10:46 but .net was originally meant for the technical meaning 22:10:51 not just the colloquial one 22:10:52 I know that 22:10:57 oh wait 22:11:01 misread you 22:11:16 but .net was originally meant for the technical meaning <-- that would include pretty much everything then 22:11:17 elliott_: I think nowadays, I conclude that "internet service provider" and "ISP" actually have somewhat different meanings 22:11:40 Vorpal: not really; a corporation not in the business of selling internet services wouldn't 22:11:56 a web server isn't really "providing" anything 22:12:01 IMO 22:12:31 hm x68/x87 really doesn't have that many general purpose instructions. It just have a lot of variants of each one. It *does* have a lot of floating point and SIMD instructions though. 22:12:39 x68 22:12:39 x68? 22:12:45 err x86 22:12:45 typo 22:12:48 the only algol 68 coprocessor 22:12:51 obviously :P 22:12:56 elliott_: well, m68k is an arch 22:13:31 it is still CISC obviously due to that nearly everything can do memory accesses. 22:13:41 pikhq_: I don't suppose there's a LOCK XADD AND ALSO JUMP HERE IF IT EXCEEDS A CERTAIN VALUE :) 22:13:49 or, to phrase that another way: 22:13:52 how do I do atomic allocations of >4k? 22:14:14 pikhq_: ouch, there's a nasty race condition even with atomic <4k allocations 22:14:29 what if you have exactly 1 byte left in the pool, and two processes do 4k allocations at once? 22:14:34 one of them gets an address /beyond/ the barrier page 22:14:38 elliott_, I doubt there is. Possibly you could optimise if you know the allocation is larger/smaller than the size and do a slow path when you don't know. 22:14:41 that might even be in some other task's valid memory 22:14:47 and it can access it freely 22:14:47 hm 22:14:55 -!- Slereah has quit (Ping timeout: 244 seconds). 22:15:14 if you restrict pools to non-concurrent access you can solve that easily, by checking the pool pointer for overflow on context switch 22:15:22 oh, hmm 22:15:24 that's actually a general flaw 22:15:31 if you allocate twice without actually accessing the RAM 22:15:33 -!- Slereah_ has joined. 22:15:40 I suppose the solution is to just ban allocating before you access a previous allocation 22:15:46 not a big deal 22:16:08 * ais523 works out how to mark a question where one of the requirements is "efficiently" 22:16:10 elliott_, you could allocate numtask*largest barrier memory? 22:16:25 luckily, this is easier than the mergesort issue, because I can populate the caches with invalid data and then see if the algo blindly trusts it 22:16:27 Vorpal: huh? 22:16:32 if it doesn't, it's not efficient 22:16:41 ais523, if applicable look for complexity? 22:16:57 Vorpal: I thought of that first, and it is possibly applicable 22:17:25 the average-case performance is probably the same, but I could make the worst-case performance for the most obvious unwanted method blow up 22:17:30 but that's probably harder to write 22:17:45 (the same in terms of complexity, that is, not in overall performance) 22:17:49 elliott_, well if you can allocate at most n bytes if you have n*tasks_in_pool barrier memory it would be safe 22:17:59 assuming you access all before next allocation 22:18:08 Vorpal: no, you would have to allocate n*tasks 22:18:20 so = millions 22:18:24 because you can have 22:18:26 hm okay 22:18:34 {2M pool page}, {4k barrier page}, {2M pool page of another task entirely} 22:18:40 if you're 1 byte from the end of the first pool page 22:18:43 increment 4k, increment 4k 22:18:46 you're in someone else's memory 22:18:51 and it won't page fault when you access it 22:19:18 -!- kmc has joined. 22:19:18 elliott_, is that 2M huge page? 22:19:24 yes 22:19:33 elliott_, x86 can do unaligned ones? 22:19:36 I'm surprised 22:19:40 well, probably not 22:19:42 it was a simplified example 22:19:49 I would expect them to have to be aligned on 2 MB boundaries 22:20:04 even if I used a 2M barrier page 22:20:07 which means your scheme would kind of not work very well, though beautiful 22:20:12 you just need to increase the number of allocations 22:20:17 well yeah 22:20:18 to show that it's still a problem 22:20:21 Vorpal: well, it'll work fine 22:20:25 2 megs is about as big as 4 megs 22:20:32 heh 22:20:34 I only need to wait a few years for everybody's memory to double 22:21:24 elliott_, I don't think I will be getting 32 GB in a hurry :P 22:22:14 actually, one problem with this allocator style is that you have to calloc pools 22:22:27 or, hmm, perhaps not 22:23:03 elliott_: you definitely don't want processes reading privileged data from leftover pools, so you have to statically ensure it's not used before alloc, or else zero it on the alloc 22:23:16 elliott_, hm why would the code be allowed to read uninitialised memory? After all isn't the system generating the machine code from @lang? 22:23:25 which could ensure that didn't happen 22:23:33 ais523: @lang programs aren't allowed to just arbitrarily read from their pool, ofc 22:23:38 elliott_: right, indeed 22:23:42 elliott_, then it shouldn't be a problem 22:23:46 they're only allowed to interpret it in ways they're allowed to 22:23:46 ais523: a Haskell compiler won't spit out code looking like that, so an @lang compiler won't either 22:23:51 Vorpal: the problem was: 22:23:59 the GC has to look at the bytes in the heap to determine object structure 22:24:06 hm 22:24:07 right 22:24:11 how does it know it's looking at a real, fully-allocated object, instead of just the garbage at the end? 22:24:14 but I think it's easy 22:24:14 elliott_: bleh, no typed GC? 22:24:21 ais523: of course it's "typed"... 22:24:23 but I think it's easy 22:24:25 because the GC is only called on overflow 22:24:30 elliott_, typed allocations. 22:24:31 so you /know/ the last object wasn't fully allocated 22:24:42 Vorpal: yes, of course; how do you think that solves the problem? 22:25:35 well the GC could see how far we allocated. And we might write a bit in a header of the allocation to indicate that we have allocated it but not yet used it 22:25:45 hm, probably rather awkward way of doing it 22:26:17 Vorpal: doesn't help 22:26:24 hm true 22:26:27 Vorpal: what happens when another CPU overflows the pool after incrementing pointer 22:26:30 but before setting the bit 22:26:39 as in 22:26:42 before _this_ cpu sets the bit 22:26:47 oh good point 22:26:47 these are all problems caused by concurrent pool access 22:26:58 why don't CPUs have transactional memory ffs 22:27:11 elliott_, iirc powerpc does 22:27:13 ! 22:27:24 that would surprise me 22:27:28 oh wait, it was load-store barriers 22:27:30 nevermind 22:27:41 still, they are considerably more powerful iirc 22:28:26 i'm tempted to just forbid concurrent access again and think of another way to do things 22:28:50 hm 22:28:58 elliott_, concurrent access has another problem anyway 22:29:06 maybe I could use small pools by default without the fancy barrier stuff and expand that on first gc 22:29:15 and that is that of cache line ownership moving between CPUs 22:29:35 Vorpal: well. that will happen anyway 22:29:36 cache lines are iirc about 64 bytes or such 22:29:51 Vorpal: since another task on the same pool will run on another CPU while other tasks on the same pool are stopped 22:30:06 I suppose I could tie pools to CPUs but that sounds like a pain on e.g. 4-core systems 22:30:11 where you just don't have many CPUs 22:30:22 (where by "CPU" i mean "core") 22:30:25 elliott_, yes but you don't want that to happen for no good reason. Sure it will happen when rescheduling. And when sharing a lock for something (and you will need locks for some stuff I bet, hardware access at the very least) 22:30:39 (like a lock for "accessing ethernet card memory mapped registers") 22:30:42 Vorpal: what happens when another CPU overflows the pool after incrementing pointer 22:30:42 but before setting the bit 22:30:42 as in 22:30:42 before _this_ cpu sets the bit 22:30:44 i thought of a solution to this 22:30:50 oh? 22:31:00 i could make the GC wait until every process on the pool allocates again 22:31:04 and thus causes another pagefault 22:31:06 heh 22:31:12 which would ensure that no partial allocations have been done 22:32:12 elliott_, actually no you can't. Segfault is a *nix term. The x86 term is general protection fault or page fault depending on what exactly you are doing 22:32:16 ;P 22:32:26 i never said segfault? 22:32:34 huh I misread 22:32:36 :( 22:32:39 twice 22:32:46 I did a double take on seeing "segfault" 22:32:48 yet it wasn't there 22:32:51 oh well 22:33:31 elliott_, anyway wouldn't that go into the next page anyway? 22:33:37 hmm, even if i don't use this fancy barrier page strategy 22:33:51 I don't see any way to avoid allocating one page per task if I'm going the "really lightweight, no concurrent access model" 22:33:55 elliott_, do you plan to have much of a stack btw? 22:34:02 or hmm yes i could 22:34:10 because allocation on a task local stack would be /way/ cheaper. 22:34:51 of course that means at least two pages anyway... with the barrier page 22:36:38 -!- ais523 has quit (Remote host closed the connection). 22:37:02 Vorpal: no it wouldn't 22:37:05 stack allocation is pointer-bumping 22:38:27 pikhq_: hmm, xadd (/without/ lock) will probably be slower than mov + add, right? thinking about a non-concurrent access scenario 22:41:44 Vorpal: stacks are basically thought to be faster because people use simpler allocators with them 22:41:52 namely, pointer-bumping 22:43:06 -!- Jafet has quit (Quit: Leaving.). 22:43:30 back 22:43:42 stack allocation is pointer-bumping <-- yes 22:43:50 elliott_, but you still need to detect stack overflow 22:44:06 yes. so it is more expensive than my allocator 22:44:30 so i don't see how a stack would help 22:44:32 elliott_, what is your GC root btw? 22:44:48 Vorpal: the continuation 22:44:51 ah 22:45:50 stack allocators have one advantage: no need to GC. Because returning just bumps the pointer the other way 22:46:01 elliott_: xadd without lock is not much more than mov+add. 22:46:08 pikhq_: right. but it is more :) 22:46:22 Vorpal: they also require a traditional notion of stack 22:46:29 well yes 22:47:29 I have to say that the rep prefix of x86 is quite curious 22:48:34 useful for boot sector golfing 22:48:39 sure 22:48:43 but not much else 22:49:05 it is truly a CISC left over 22:49:29 so is x86 22:50:57 -!- derrik has quit (Quit: nights). 22:51:28 elliott_, touche 22:53:39 "Any VEX-encoded instruction with a LOCK prefix preceding VEX will #UD." <-- it doesn't say anything else under "VEX and the LOCK prefix". Like it would be useful to say if it works in the other order. 22:53:43 fuck you intel 22:54:00 hm it doesn't 22:54:08 because VEX isn't a prefix anyway 22:54:14 so why no LOCK on VEX? 23:03:51 hmm, looks like my tasks have to take up at least 144 bytes 23:04:01 elliott_, impressive 23:04:10 _at least_ :P 23:04:17 that's just the number of registers on x86-64, including IP 23:04:28 ofc if i don't use all registers for computation then they can take less... 23:04:41 or if certain registers are always used as like scratch space before being put into memory 23:04:46 then I can avoid storing them 23:04:52 elliott_, "A newly spawned Erlang process uses 309 words of memory in the non-SMP emulator without HiPE support. (SMP support and HiPE support will both add to this size.)" 23:04:59 so far you beat erlang 23:05:10 hmm, why do they need that much? 23:05:14 2.4 kilobytes is quite a lot 23:05:17 don't know 23:05:35 elliott_, it may include the default stack 23:05:36 perhaps 23:05:41 gah, i just thought of a response to something ais said, but he's left 23:05:54 use @tell? 23:06:09 that doesn't have immediate payoff :) but fine! 23:06:18 elliott_, "The size includes 233 words for the heap area (which includes the stack). The garbage collector will increase the heap as needed." 23:06:22 elliott_, that is why it is so large 23:06:33 @tell ais523 there's no real problem with a million-task scheduler with current technology; the issue is more adapting for various patterns of blocked/nonblocked 23:06:33 Consider it noted. 23:07:08 @tell ais523 in @, there's no such thing as a "blocked task"; a blocked task's data (not necessarily including its pool data, just the pointer) is moved into whatever's being /blocked on/ 23:07:09 Consider it noted. 23:07:16 @tell ais523 and then removed from the scheduler's list of tasks 23:07:17 Consider it noted. 23:07:18 elliott_, anyway so the real overhead is 76 words 23:07:35 @tell ais523 that is, sockets know which threads are blocked on them, and resume those threads when they receive data or whatever 23:07:35 Consider it noted. 23:07:37 elliott_, which is far smaller 23:07:42 Vorpal: right, 608 bytes 23:08:03 elliott_, 304 on 32-bit 23:08:27 irrelevant 23:08:32 oh? 23:08:36 32-bit systems still exist 23:08:41 not for long 23:08:51 not in the pc market anyway 23:08:54 well yeah 23:09:08 elliott_, but globally most processors are likely 16-bit or 8-bit still 23:09:14 yeah, but they don't run erlang 23:09:17 true 23:09:25 also, i think 32-bit is the most common nowadays actually, because of ARM in the embedded space 23:09:26 and things like that 23:09:34 elliott_, still erlang can run on vxworks. Which opens up a whole embedded market 23:09:37 full CPUs in embedded stuff is becomming more common 23:09:49 unfortunately I don't think @ will work very well on 32-bit 23:09:53 maybe in the embedded space 23:09:58 heh 23:10:04 not kidding 23:10:14 what kind of disks do vxworks devices have :P 23:10:16 elliott_, 64-bit in embedded is rare. it is mostly consoles and PCs that are 64-bit 23:11:03 elliott_, hm... the ones I used at university had either flash with some weird connector or plain CF cards. 23:11:08 i mean, size 23:11:23 elliott_, well I have a CF card somewhere. Let me find a ruler ;) 23:11:32 elliott_, anyway it was a dev system. Kind of high end. 23:11:43 like x86, pentium, 500 MHz 23:11:50 or something absurdly overpowered like that 23:11:57 1 or 2 GB flash probably 23:12:08 basically, a 32-bit @ system can address 4 gigabytes, total, including disk 23:12:10 elliott_, but it varies depending on applications :P 23:12:16 elliott_, ouch 23:12:25 so it works fine in like most embedded scenarios i guess 23:12:28 but not on a desktop 23:12:42 i can think of workarounds, but they're all sloooooooow 23:12:52 anyway there is large file system support on other systems. Obviously not on @ 23:13:07 elliott_, wait, x86-64 systems actually have 48 bits virtual address space right? 23:13:10 Vorpal: well it doesn't really work because of the uniform address space 23:13:18 Vorpal: Currently. 23:13:22 pikhq_, indeed 23:13:23 basically you'd need to store all pointers as large filesystem addresses 23:13:30 dereferencing those would be slow as shit 23:13:30 That's a limit of the MMU, not the ISA. 23:13:44 that means 35.18 TB 23:14:12 Vorpal: and? :P 23:14:24 elliott_, that is kind of close to modern storage size. 23:15:00 Vorpal: when single machines start addressing 35 terabytes, AMD and Intel will start releasing CPUs with MMUs that can address 64 bits. 23:15:04 or 54 bits or whatever :P 23:15:06 elliott_: Better/worse: you could use segmentation. 23:15:21 elliott_, I have like slightly more than 1/17th of that in disks in my computer 23:15:29 pikhq_: I don't see how that would work; pointers would have to store the segment they're in 23:15:35 Vorpal: moore's law doesn't work _that_ fast. 23:15:36 elliott_, I meant for disks, Not for ram 23:15:48 elliott_, since you do uniform address space 23:15:53 the disk size matters for you 23:15:57 Did I contradict that? 23:16:02 nope 23:16:21 elliott_, I was just finishing my line of thought before reading further. I use blocking IO 23:16:26 Vorpal: I'm pretty sure that the MMU bit width will increase when we're living in the space age and people have 35 terabytes of disk. 23:16:26 in my brain 23:16:36 elliott_: Segments map to physical space. Recent x86 has 36-bit address space. :P 23:16:38 Even if it doesn't, 35 terabytes is a lot of storage. 23:16:54 I doubt you, as a person, will need >35 terabytes of personal storage before @ takes over the world. 23:17:05 pikhq_: that's still tiny :P 23:17:24 elliott_: Also, alternately you *could* make it so that far pointer dereferencing is the expensive operation. 23:17:31 Which nets you a potentially 46-bit address space. 23:17:40 This would be an *insane* hack, though. 23:18:07 elliott_, 35 TB is ~1501 blueray disc 23:18:25 Vorpal: I will consider your concerns if you personally buy 1501 blu-ray discs. 23:18:39 nah I'll torrent them 23:18:49 elliott_, I wonder how much traffic I download in a year 23:18:51 Vorpal: If you use sane encodings, chop a order of magnitude off that. 23:18:55 (x264 is awesome shit) 23:18:56 err how much traffic downstream I mean 23:19:09 pikhq_, who said movies 23:19:18 * elliott_ attempts to find a blank blu-ray on Amazon. 23:19:20 pikhq_, games on blueray happens nowdays 23:19:31 pikhq_, I downloaded a 25 GB game at one point 23:19:33 Vorpal: Technically, yes. They're generally empty. 23:19:44 pikhq_, nope. Rage was 25 GB download 23:19:50 Due to targetting DVD platforms as well, and nobody likes multiple disks. 23:19:52 or 24 or so 23:20:09 Jesus, what did they include, the genomes of all sequenced species? 23:20:18 pikhq_, really bad texture quality 23:20:22 pikhq_, the install size was 27 GB iirc 23:20:49 pikhq_, iirc they said the raw data of the game they had on their development servers was over 1 TB 23:21:15 pikhq_, and Rage is a really bad game. Boring, uninspired story, mediocre gameplay 23:21:22 and quite uneven texture quality 23:21:32 everything from state of the art to something utterly jagged. 23:21:43 -!- kmc has quit (Quit: Leaving). 23:22:19 "Higher res is better. Derp, scale!"? 23:22:39 pikhq_, it feels like a tech demo for the engine to tell the truth :P 23:23:26 pikhq_, the skydome was truly impressive though 23:24:58 pikhq_, anyway there are many games that come on dual layer DVDs these days 23:25:19 iirc witcher 2 was about 7 GB large download. Somewhat more when installed on disk 23:25:35 and that game has high texture quality and good gameplay and everything :P 23:26:02 hm system requirements is 16 GB free disk 23:27:17 pikhq_, speaking of which... that is a rare game these days. Witcher 2 is completely DRM free. 23:27:39 (except when bought from steam iirc) 23:29:56 Steam has DRM? 23:30:07 elliott_, where have you been? 23:30:12 Not using Steam. 23:30:18 right 23:30:39 That sucks. 23:30:42 elliott_, steam has DRM that is fairly easy to work around by replacing a few dll files 23:30:57 Easier to pirate, no? 23:31:00 replacement ones are kind of well developed already 23:31:05 elliott_, pretty much. 23:31:46 not all steam games use the drm of course 23:32:10 generally you know when a game refuses to run without steam running, then it uses the drm 23:32:13 elliott_, like skyrim does 23:32:22 (note: easy to work around :P) 23:32:25 Gross. 23:32:51 elliott_, yes we are talking about steam indeed :P 23:33:07 Why do people like Steam again? 23:33:49 elliott_, because it was first and it is convenient. And there are far worse DRM examples. 23:34:13 Vorpal: But I've actually seen people rejoice when games they already own became available on Steam. 23:34:18 elliott_, and because it has all the games (pretty much). Which it does because it is popular with the users. 23:34:25 elliott_, really? 23:34:27 why? 23:34:35 elliott_, is it for the steam achievements? 23:34:44 maybe... 23:34:47 Vorpal: The only reasons I've heard are because of the "social" features of it and the achievements and crap. Which I find completely incomprehensible. 23:35:08 I mean, I'd prefer to just ask people if they want a game rather than cyberstalking them for the purpose. 23:35:11 elliott_, oh yeah you can use it for easy invites to friends for multiplayer games iirc. 23:35:14 which is kind of nice 23:35:16 And achievements are a scourge. 23:35:31 Achievements are what happen when you can't think of a decent in-game way to reward players for doing things. 23:35:37 So you decide to annoy them instead 23:35:40 s/$/./ 23:35:48 elliott_, it is easier to click a friend's name in a list than to ask them to provide a port number and so on 23:36:23 * elliott_ is used to playing multiplayer games with decent lobby systems. 23:36:33 Admittedly skipping the lobby entirely would be preferable. 23:36:35 Achievements are what happen when you can't think of a decent in-game way to reward players for doing things. <-- I like stuff that are kind of like achievements but are for the current game only and have an in game effect 23:36:50 So, not achievements. 23:37:24 elliott_, like, in witcher 2, if you stay within a protective spell bubble during a part of the introduction of chapter 1 you get a +5 or something bonus to something 23:37:29 stuff like that 23:37:57 or following a certain path doing a certain mission within certain parameters grants you 100 extra carrying capacity 23:38:41 elliott_, anyway you might want to reward a player who went through the entire game without killing any enemy, using sneaking and such instead. 23:38:46 how would you do that? 23:38:53 achievement is the usual answer 23:38:57 Well, badges at the end are OK 23:39:04 hm 23:39:06 Achievements that happen mid-game not so much 23:39:10 I mean 23:39:10 true 23:39:13 If it's just for things like easter eggs sure 23:39:17 But if it's like "100 kills" fuck that 23:40:04 elliott_, what about stuff like "navigated down a steep hill without taking fall damage". Yogscast suggested that should be an achievement in skyrim (it isn't, it has the boring type of achievements, mostly "did questline x") 23:40:25 of course it would be hard to measure that 23:40:36 -!- pumpkin has joined. 23:40:57 elliott_, but yes, I seen pretty bad achievements. And I seen less bad ones. 23:41:03 The achievement comes from managing that in the first place :P 23:41:08 heh 23:41:16 If it's obvious that you've done something hard, you don't need to yell at players that they've done it 23:41:22 elliott_, but you want something you can brag about on your steam profile! 23:41:25 ;P 23:42:25 pikhq_: Do you know much about hardware virtualisation 23:43:02 elliott_, anyway I remember reading about some game where the devs put in achievements for stuff they thought were so improbable that they were for all practical purposes impossible. Just to see how long it took for players to figure out a way to do them. 23:43:09 -!- Jafet has joined. 23:43:19 all were done within a year iirc 23:43:23 forgot which game it was 23:43:28 heh 23:43:37 -!- copumpkin has quit (Ping timeout: 248 seconds). 23:44:39 elliott_, anyway gamersgate is a better online store than steam really. No silly client crap. 23:46:09 elliott_, another one I heard was good but which I never used myself is desura. Mostly focused on indie stuff iirc 23:46:21 elliott_, so there are alternatives to steam that are less shitty 23:46:25 just not as popular 23:46:34 Desura has a client thing. 23:46:50 elliott_, yes, but a less obnoxious one 23:46:52 by far 23:47:06 What ever happened to just delivering binaries. 23:47:35 elliott_, that is gamersgate. They let you download a downloader program basically. And then that downloads the binary. 23:47:37 so almost :P 23:47:51 I guess a downloader makes sense on windows because I doubt IE can resume a broken download 23:47:57 Nobody uses IE 23:48:02 But Firefox sucks at resuming downloads 23:48:05 Probably Chrome too 23:48:05 that too 23:48:14 elliott_, so that is why they use a downloader 23:48:18 I use wget for such stuff 23:48:23 wget -c works wonders 23:49:54 * Phantom_Hoover → sleep 23:49:55 -!- Phantom_Hoover has quit (Quit: Leaving). 23:50:04 heh gamersgate is a Swedish company? Didn't know that 23:50:25 -!- nooga has quit (Ping timeout: 244 seconds). 23:51:39 Why does scan.co.uk have to be so unusable. 23:53:28 elliott_: Not much. 23:53:32 pikhq_: Damn 23:53:56 pikhq_: So you wouldn't know how expensive something in ring 0 calling on the hypervisor would be?