| 2024-10-03 00:01:09 +0200 | <haskellbridge> | <sm> "hell" on HN: https://news.ycombinator.com/item?id=41694767 |
| 2024-10-03 00:01:34 +0200 | <probie> | % let{f x=print x>>pure x;tleft=fmap($ []).foldr(\x k -> liftA2(flip(.))k(fmap(:)x))(pure$id)}in tleft $ map f [1..5] -- Probably worse than two reverses because it spills the list to the stack |
| 2024-10-03 00:01:34 +0200 | <yahb2> | 5 ; 4 ; 3 ; 2 ; 1 ; [1,2,3,4,5] |
| 2024-10-03 00:02:00 +0200 | merijn | (~merijn@204-220-045-062.dynamic.caiway.nl) (Ping timeout: 252 seconds) |
| 2024-10-03 00:05:57 +0200 | peterbecich | (~Thunderbi@syn-047-229-123-186.res.spectrum.com) peterbecich |
| 2024-10-03 00:12:48 +0200 | merijn | (~merijn@204-220-045-062.dynamic.caiway.nl) merijn |
| 2024-10-03 00:17:16 +0200 | codaraxis___ | (~codaraxis@user/codaraxis) (Ping timeout: 244 seconds) |
| 2024-10-03 00:17:24 +0200 | merijn | (~merijn@204-220-045-062.dynamic.caiway.nl) (Ping timeout: 252 seconds) |
| 2024-10-03 00:18:49 +0200 | weary-traveler | (~user@user/user363627) (Remote host closed the connection) |
| 2024-10-03 00:23:16 +0200 | peterbecich | (~Thunderbi@syn-047-229-123-186.res.spectrum.com) (Ping timeout: 252 seconds) |
| 2024-10-03 00:24:27 +0200 | codaraxis | (~codaraxis@user/codaraxis) Codaraxis |
| 2024-10-03 00:28:20 +0200 | merijn | (~merijn@204-220-045-062.dynamic.caiway.nl) merijn |
| 2024-10-03 00:33:04 +0200 | merijn | (~merijn@204-220-045-062.dynamic.caiway.nl) (Ping timeout: 260 seconds) |
| 2024-10-03 00:33:44 +0200 | Sgeo | (~Sgeo@user/sgeo) Sgeo |
| 2024-10-03 00:34:33 +0200 | JuanDaugherty | (~juan@user/JuanDaugherty) JuanDaugherty |
| 2024-10-03 00:37:12 +0200 | ljdarj | (~Thunderbi@user/ljdarj) (Ping timeout: 276 seconds) |
| 2024-10-03 00:39:31 +0200 | athan | (~athan@syn-098-153-145-140.biz.spectrum.com) (Quit: Konversation terminated!) |
| 2024-10-03 00:42:03 +0200 | notzmv | (~daniel@user/notzmv) (Read error: Connection reset by peer) |
| 2024-10-03 00:43:56 +0200 | merijn | (~merijn@204-220-045-062.dynamic.caiway.nl) merijn |
| 2024-10-03 00:45:31 +0200 | neuroevolutus | (~neuroevol@37.19.200.152) (Ping timeout: 256 seconds) |
| 2024-10-03 00:48:47 +0200 | merijn | (~merijn@204-220-045-062.dynamic.caiway.nl) (Ping timeout: 244 seconds) |
| 2024-10-03 00:50:00 +0200 | tromp | (~textual@92-110-219-57.cable.dynamic.v4.ziggo.nl) (Quit: My iMac has gone to sleep. ZZZzzz…) |
| 2024-10-03 00:55:08 +0200 | troojg | (~troojg@user/troojg) troojg |
| 2024-10-03 00:57:53 +0200 | merijn | (~merijn@204-220-045-062.dynamic.caiway.nl) merijn |
| 2024-10-03 01:00:45 +0200 | ash3en | (~Thunderbi@ip1f10cbd6.dynamic.kabel-deutschland.de) ash3en |
| 2024-10-03 01:00:50 +0200 | ash3en | (~Thunderbi@ip1f10cbd6.dynamic.kabel-deutschland.de) (Client Quit) |
| 2024-10-03 01:02:42 +0200 | merijn | (~merijn@204-220-045-062.dynamic.caiway.nl) (Ping timeout: 265 seconds) |
| 2024-10-03 01:12:43 +0200 | <c_wraith> | does STM document its consistency properties anywhere? istr it's the equivalent of read-committed, rather than fully linearizable? |
| 2024-10-03 01:13:15 +0200 | supercode | (~supercode@user/supercode) supercode |
| 2024-10-03 01:13:19 +0200 | merijn | (~merijn@204-220-045-062.dynamic.caiway.nl) merijn |
| 2024-10-03 01:18:45 +0200 | merijn | (~merijn@204-220-045-062.dynamic.caiway.nl) (Ping timeout: 248 seconds) |
| 2024-10-03 01:20:05 +0200 | <mauke> | what's the difference? |
| 2024-10-03 01:23:36 +0200 | <geekosaur> | I think it might be only by reference (there's a paper from Intel Research describing it) |
| 2024-10-03 01:24:38 +0200 | Katarushisu | (~Katarushi@finc-20-b2-v4wan-169598-cust1799.vm7.cable.virginm.net) (Quit: Ping timeout (120 seconds)) |
| 2024-10-03 01:24:56 +0200 | Katarushisu | (~Katarushi@finc-20-b2-v4wan-169598-cust1799.vm7.cable.virginm.net) Katarushisu |
| 2024-10-03 01:29:39 +0200 | merijn | (~merijn@204-220-045-062.dynamic.caiway.nl) merijn |
| 2024-10-03 01:30:07 +0200 | sawilagar | (~sawilagar@user/sawilagar) (Ping timeout: 244 seconds) |
| 2024-10-03 01:30:56 +0200 | <c_wraith> | mauke: with read-committed you can read a set of values that never would have existed together if all transactions were serialized. |
| 2024-10-03 01:32:30 +0200 | <geekosaur> | I don't think you can get into that situation with STM; the only such sets wouldn't be observable, because anything that could observe them would be forced to `retry` and end up with a consistent set? |
| 2024-10-03 01:32:34 +0200 | xff0x | (~xff0x@2405:6580:b080:900:409b:fd54:4c14:6dc) (Ping timeout: 260 seconds) |
| 2024-10-03 01:33:15 +0200 | <c_wraith> | hmm. possibly so. I tried a few traces that typically show that, and they did all retry with STM semantics. |
| 2024-10-03 01:33:18 +0200 | <geekosaur> | something observing program state from outside could potentially see such states |
| 2024-10-03 01:33:47 +0200 | <c_wraith> | well, something observing from the outside can see all kinds of stuff with STM |
| 2024-10-03 01:33:52 +0200 | <geekosaur> | yep |
| 2024-10-03 01:34:11 +0200 | <geekosaur> | this should all be covered in the Intel paper |
| 2024-10-03 01:34:19 +0200 | merijn | (~merijn@204-220-045-062.dynamic.caiway.nl) (Ping timeout: 260 seconds) |
| 2024-10-03 01:40:21 +0200 | neuroevolutus | (~neuroevol@37.19.200.152) neuroevolutus |
| 2024-10-03 01:45:04 +0200 | merijn | (~merijn@204-220-045-062.dynamic.caiway.nl) merijn |
| 2024-10-03 01:45:13 +0200 | xff0x | (~xff0x@2405:6580:b080:900:409b:fd54:4c14:6dc) |
| 2024-10-03 01:46:43 +0200 | neuroevolutus | (~neuroevol@37.19.200.152) (Ping timeout: 256 seconds) |
| 2024-10-03 01:49:32 +0200 | Smiles | (uid551636@id-551636.lymington.irccloud.com) (Quit: Connection closed for inactivity) |
| 2024-10-03 01:49:41 +0200 | merijn | (~merijn@204-220-045-062.dynamic.caiway.nl) (Ping timeout: 248 seconds) |
| 2024-10-03 01:55:28 +0200 | <Lears> | c_wraith: <https://www.microsoft.com/en-us/research/wp-content/uploads/2005/01/2005-ppopp-composable.pdf> (linked indirectly from Control.Concurrent.STM) is /the/ STM paper if GHC's particular form/extension of STM is what you're interested in. I imagine it has the answer you're looking for, though I'd be very surprised if such states were observable. |
| 2024-10-03 01:55:48 +0200 | <dolio> | c_wraith: Yeah, that's true. |
| 2024-10-03 01:56:06 +0200 | <c_wraith> | ugh, why did my irc client think the > is part of the link? bad client! |
| 2024-10-03 01:56:26 +0200 | <dolio> | This is discussed in Revisting Software Transactional Memory in Haskell. |
| 2024-10-03 01:56:31 +0200 | alexherbo2 | (~alexherbo@2a02-8440-3118-adab-ad64-111d-10db-8d9d.rev.sfr.net) (Remote host closed the connection) |
| 2024-10-03 01:57:42 +0200 | alexherbo2 | (~alexherbo@2a02-8440-3118-adab-f186-fae0-9a30-1276.rev.sfr.net) alexherbo2 |
| 2024-10-03 02:00:09 +0200 | <dolio> | Oh, I guess unless the implementation in that paper has since replaced the original implementation in GHC, because the one in that paper does ensure every transaction sees a consistent memory state (I think). |
| 2024-10-03 02:00:29 +0200 | merijn | (~merijn@204-220-045-062.dynamic.caiway.nl) merijn |
| 2024-10-03 02:01:14 +0200 | alexherbo2 | (~alexherbo@2a02-8440-3118-adab-f186-fae0-9a30-1276.rev.sfr.net) (Remote host closed the connection) |
| 2024-10-03 02:01:46 +0200 | <dolio> | They call the property that ensures that, 'opacity.' |
| 2024-10-03 02:03:57 +0200 | <c_wraith> | I'm just getting there in the paper... |
| 2024-10-03 02:04:50 +0200 | merijn | (~merijn@204-220-045-062.dynamic.caiway.nl) (Ping timeout: 252 seconds) |
| 2024-10-03 02:04:55 +0200 | <c_wraith> | it would be nice to know if GHC switched inplemrntations |
| 2024-10-03 02:05:04 +0200 | <dolio> | Yeah. That I don't know. |
| 2024-10-03 02:08:51 +0200 | troojg | (~troojg@user/troojg) (Ping timeout: 276 seconds) |
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| 2024-10-03 03:42:24 +0200 | shailangsa | (~shailangs@host86-182-139-82.range86-182.btcentralplus.com) shailangsa |
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| 2024-10-03 03:54:11 +0200 | merijn | (~merijn@204-220-045-062.dynamic.caiway.nl) merijn |
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| 2024-10-03 04:26:46 +0200 | codaraxis__ | (~codaraxis@user/codaraxis) Codaraxis |
| 2024-10-03 04:29:40 +0200 | Digitteknohippie | (~user@user/digit) Digit |
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| 2024-10-03 04:31:17 +0200 | lambdabot | (~lambdabot@haskell/bot/lambdabot) lambdabot |
| 2024-10-03 04:31:17 +0200 | ChanServ | +v lambdabot |
| 2024-10-03 04:34:48 +0200 | identity | (~identity@user/ZharMeny) (Quit: ERC 5.5.0.29.1 (IRC client for GNU Emacs 29.4)) |
| 2024-10-03 04:36:07 +0200 | Digitteknohippie | Digit |
| 2024-10-03 04:40:50 +0200 | merijn | (~merijn@204-220-045-062.dynamic.caiway.nl) merijn |
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| 2024-10-03 04:49:26 +0200 | Smiles | (uid551636@id-551636.lymington.irccloud.com) Smiles |
| 2024-10-03 04:51:07 +0200 | neuroevolutus | (~neuroevol@37.19.200.152) neuroevolutus |
| 2024-10-03 04:51:29 +0200 | komikat | (~user@218.185.248.66) (Ping timeout: 260 seconds) |
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| 2024-10-03 04:56:46 +0200 | neuroevolutus | (~neuroevol@146.70.211.46) neuroevolutus |
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| 2024-10-03 05:06:13 +0200 | zmt01 | (~zmt00@user/zmt00) zmt00 |
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| 2024-10-03 05:19:32 +0200 | aforemny_ | (~aforemny@i59F4C77A.versanet.de) aforemny |
| 2024-10-03 05:20:48 +0200 | aforemny | (~aforemny@2001:9e8:6cd7:c200:342e:20f9:8752:4727) (Ping timeout: 265 seconds) |
| 2024-10-03 05:26:03 +0200 | weary-traveler | (~user@user/user363627) (Remote host closed the connection) |
| 2024-10-03 05:28:11 +0200 | merijn | (~merijn@204-220-045-062.dynamic.caiway.nl) merijn |
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| 2024-10-03 05:41:39 +0200 | billchenchina- | (~billchenc@2a0d:2580:ff0c:1:e3c9:c52b:a429:5bfe) billchenchina |
| 2024-10-03 05:43:18 +0200 | Lord_of_Life | (~Lord@user/lord-of-life/x-2819915) (Ping timeout: 246 seconds) |
| 2024-10-03 05:43:44 +0200 | merijn | (~merijn@204-220-045-062.dynamic.caiway.nl) merijn |
| 2024-10-03 05:44:18 +0200 | Lord_of_Life | (~Lord@user/lord-of-life/x-2819915) Lord_of_Life |
| 2024-10-03 05:45:47 +0200 | <haskellbridge> | <thirdofmay18081814goya> can all problems regarding whether or not a computable function terminates be reduced to a logic program? |
| 2024-10-03 05:47:00 +0200 | <EvanR> | is it even a computable function if it doesn't terminate |
| 2024-10-03 05:47:09 +0200 | <EvanR> | for some inputs |
| 2024-10-03 05:47:39 +0200 | <EvanR> | if not, that makes some undecidable problems computable |
| 2024-10-03 05:48:27 +0200 | merijn | (~merijn@204-220-045-062.dynamic.caiway.nl) (Ping timeout: 244 seconds) |
| 2024-10-03 05:49:49 +0200 | <haskellbridge> | <thirdofmay18081814goya> EvanR: yeah I think termination and computability are distinct things |
| 2024-10-03 05:50:00 +0200 | <EvanR> | :thonk: |
| 2024-10-03 05:50:13 +0200 | <EvanR> | not saying they are the same |
| 2024-10-03 05:51:54 +0200 | pavonia | (~user@user/siracusa) siracusa |
| 2024-10-03 05:51:59 +0200 | <haskellbridge> | <thirdofmay18081814goya> i mean i think they are independent from one another, and termination or non-termination is a property of computable functions |
| 2024-10-03 05:52:56 +0200 | <EvanR> | a mathematical function from integers to integers is computable if there's an algorithm which can implement this function, so non-termination wouldn't come up here because of the codomain in the premise |
| 2024-10-03 05:53:16 +0200 | <EvanR> | these functions wouldn't be missing any answers, and so an non-termination would be a failure to implement |
| 2024-10-03 05:53:42 +0200 | <EvanR> | any* non-termination |
| 2024-10-03 05:54:21 +0200 | <Lears> | thirdofmay: Computable functions are mathematical functions; they have no inherent notion of implementation or termination; they're defined at every argument. |
| 2024-10-03 05:54:34 +0200 | <Lears> | You probably want the "general recursive functions". |
| 2024-10-03 05:55:50 +0200 | <Lears> | "reduced to a logic program" is also unclear. |
| 2024-10-03 05:55:54 +0200 | <EvanR> | you could posit a mathematical function into a space that includes an additional bottom value |
| 2024-10-03 05:56:07 +0200 | <EvanR> | but I figured that'd be weird |
| 2024-10-03 05:56:48 +0200 | <EvanR> | and use a convention that "computing the bottom" means the algorithm provably freezes up xD |
| 2024-10-03 05:57:12 +0200 | <EvanR> | haskell maths |
| 2024-10-03 05:58:30 +0200 | <haskellbridge> | <thirdofmay18081814goya> ty for ref |
| 2024-10-03 05:58:50 +0200 | mud | (~mud@user/kadoban) (Quit: quit) |
| 2024-10-03 05:59:09 +0200 | merijn | (~merijn@204-220-045-062.dynamic.caiway.nl) merijn |
| 2024-10-03 06:00:48 +0200 | cyphase | (~cyphase@user/cyphase) (Ping timeout: 246 seconds) |
| 2024-10-03 06:01:10 +0200 | cyphase | (~cyphase@user/cyphase) cyphase |
| 2024-10-03 06:02:30 +0200 | mud | (~mud@user/kadoban) kadoban |
| 2024-10-03 06:03:33 +0200 | merijn | (~merijn@204-220-045-062.dynamic.caiway.nl) (Ping timeout: 248 seconds) |
| 2024-10-03 06:06:56 +0200 | mud | (~mud@user/kadoban) (Client Quit) |
| 2024-10-03 06:08:21 +0200 | peterbecich | (~Thunderbi@syn-047-229-123-186.res.spectrum.com) peterbecich |
| 2024-10-03 06:10:07 +0200 | merijn | (~merijn@204-220-045-062.dynamic.caiway.nl) merijn |
| 2024-10-03 06:10:25 +0200 | mud | (~mud@user/kadoban) kadoban |
| 2024-10-03 06:12:45 +0200 | Tisoxin | (~Ikosit@user/ikosit) Ikosit |
| 2024-10-03 06:14:48 +0200 | merijn | (~merijn@204-220-045-062.dynamic.caiway.nl) (Ping timeout: 246 seconds) |
| 2024-10-03 06:15:59 +0200 | amano | (amano@gateway/vpn/airvpn/amano) amano |
| 2024-10-03 06:16:36 +0200 | <amano> | Let's assume StateT (DataType a) m a. Can StateT replace DataType a with DataType b? |
| 2024-10-03 06:17:10 +0200 | <amano> | I mean StateT (DataType a) m () |
| 2024-10-03 06:20:37 +0200 | <Lears> | :t StateT |
| 2024-10-03 06:20:38 +0200 | <lambdabot> | (s -> m (a, s)) -> StateT s m a |
| 2024-10-03 06:20:41 +0200 | <c_wraith> | nothing in mtl/transformers provides that. mmorph doesn't seem to provide that. lens *does*, as part of the Zoom interface. |
| 2024-10-03 06:21:20 +0200 | <c_wraith> | the trick, and why it appears in lens, is that the transformation needs to be bidirectional |
| 2024-10-03 06:21:51 +0200 | <amano> | Then, I have to use existential typeclass in a data type? |
| 2024-10-03 06:22:19 +0200 | <c_wraith> | uh, not sure what you mean by that. |
| 2024-10-03 06:22:32 +0200 | <Lears> | StateT uses the same type for the input state as the output state; so not unless you change both. If you lift this restriction with your own StateT', then you cannot make it a Monad, though you can make it an indexed monad. |
| 2024-10-03 06:23:01 +0200 | <Lears> | If the type parameter to `DataType` is recoverable, then yes, it's simplest just to hide it with `Some DataType`. |
| 2024-10-03 06:23:23 +0200 | <c_wraith> | I just mean that in (s -> m (a, s)), s appears in both positive and negative position. This means it's not covariant or contravariant - you can't map it simply. |
| 2024-10-03 06:23:42 +0200 | <c_wraith> | Lens is all about bidirectional mapping, so it handles that case relatively easily. |
| 2024-10-03 06:25:54 +0200 | merijn | (~merijn@204-220-045-062.dynamic.caiway.nl) merijn |
| 2024-10-03 06:26:29 +0200 | <amano> | I mean data SomeType = forall a. TypeClass a => SomeType a |
| 2024-10-03 06:26:33 +0200 | <amano> | This is existential typeclass |
| 2024-10-03 06:27:11 +0200 | <c_wraith> | and it's kinda useless. |
| 2024-10-03 06:27:16 +0200 | <amano> | Why? |
| 2024-10-03 06:27:41 +0200 | <amano> | This is the only way I know to use multiple typeclass instances in StateT. |
| 2024-10-03 06:27:44 +0200 | <c_wraith> | it's no different from just passing around a function, or a record of them. |
| 2024-10-03 06:28:03 +0200 | <amano> | I know it can be represented as a record of functions.... |