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2020-10-19 19:15:08 <lambdabot> Maybe you meant: wn v rc pl id do bf @ ? .
2020-10-19 19:15:10 <hyperisco> crestfallen, did you realise that @[] is not a value and not an empty list?
2020-10-19 19:15:17 → cosimone joins (~cosimone@2001:b07:ae5:db26:d849:743b:370b:b3cd)
2020-10-19 19:16:11 → recon_- joins (~quassel@2602:febc:0:b6::6ca2)
2020-10-19 19:16:22 <crestfallen> thanks all, yeah hyperisco it is a setting, so ghci knows what f you want pure to indicate
2020-10-19 19:16:32 <crestfallen> indicate? word choice
2020-10-19 19:17:49 <hyperisco> if you like, all types are passed as parameters, but normally they are passed implicitly by the compiler
2020-10-19 19:18:06 → conal joins (~conal@64.71.133.70)
2020-10-19 19:18:22 <hyperisco> if you want to pass a type explicitly, you can use TypeApplications to do so
2020-10-19 19:18:34 → ystael joins (~ystael@168.sub-174-196-209.myvzw.com)
2020-10-19 19:19:02 <crestfallen> ok yeah so if you set it, and wanted to write a full expression, what would the (shortened) expression look like?
2020-10-19 19:19:24 <crestfallen> I'm assuming it is a more terse expression
2020-10-19 19:19:26 <hyperisco> I am not sure what you are asking for
2020-10-19 19:20:18 → Lycurgus joins (~niemand@98.4.96.235)
2020-10-19 19:20:29 <crestfallen> Like instead of using Just ((:) 2) <*> (pure [])
2020-10-19 19:21:02 × knupfer quits (~Thunderbi@200116b82c450700441c7c862ee5eb73.dip.versatel-1u1.de) (Quit: knupfer)
2020-10-19 19:21:07 <crestfallen> if it were to be already set, could you have a shorter expression?
2020-10-19 19:21:20 → knupfer joins (~Thunderbi@200116b82c45070071699ce90995afec.dip.versatel-1u1.de)
2020-10-19 19:21:26 × knupfer quits (~Thunderbi@200116b82c45070071699ce90995afec.dip.versatel-1u1.de) (Client Quit)
2020-10-19 19:21:39 → knupfer joins (~Thunderbi@200116b82c4507006c8b8e4546ef723c.dip.versatel-1u1.de)
2020-10-19 19:21:39 × knupfer quits (~Thunderbi@200116b82c4507006c8b8e4546ef723c.dip.versatel-1u1.de) (Client Quit)
2020-10-19 19:21:58 <geekosaur> if you had one where it could be inferred
2020-10-19 19:22:21 <geekosaur> have you tried asking ghci the type of the expression with and without the @[] ?
2020-10-19 19:22:24 <hyperisco> types can be inferred, values cannot be (if we ignore ImplicitParams)
2020-10-19 19:22:27 → knupfer joins (~Thunderbi@200116b82c450700f42c1c1a4887d4fe.dip.versatel-1u1.de)
2020-10-19 19:22:27 × knupfer quits (~Thunderbi@200116b82c450700f42c1c1a4887d4fe.dip.versatel-1u1.de) (Client Quit)
2020-10-19 19:22:43 × recon_- quits (~quassel@2602:febc:0:b6::6ca2) (Remote host closed the connection)
2020-10-19 19:23:17 → knupfer joins (~Thunderbi@200116b82c450700018f4d4b438b9de8.dip.versatel-1u1.de)
2020-10-19 19:23:17 × knupfer quits (~Thunderbi@200116b82c450700018f4d4b438b9de8.dip.versatel-1u1.de) (Client Quit)
2020-10-19 19:23:28 → knupfer joins (~Thunderbi@200116b82c450700a035f643f76eb1ae.dip.versatel-1u1.de)
2020-10-19 19:23:32 <crestfallen> let me try that thanks geekosaur
2020-10-19 19:23:33 × knupfer quits (~Thunderbi@200116b82c450700a035f643f76eb1ae.dip.versatel-1u1.de) (Read error: Connection reset by peer)
2020-10-19 19:23:33 <hyperisco> you can golf your code there but it isn't going to be helped by a type application
2020-10-19 19:23:38 → coot_ joins (~coot@37.30.52.239.nat.umts.dynamic.t-mobile.pl)
2020-10-19 19:23:43 → knupfer joins (~Thunderbi@200116b82c4507005d2376b981a68d64.dip.versatel-1u1.de)
2020-10-19 19:23:51 → recon_- joins (~quassel@2602:febc:0:b6::6ca2)
2020-10-19 19:23:52 <crestfallen> thanks one moment
2020-10-19 19:24:45 × coot quits (~coot@37.30.52.68.nat.umts.dynamic.t-mobile.pl) (Ping timeout: 240 seconds)
2020-10-19 19:24:45 coot_ is now known as coot
2020-10-19 19:25:37 → ggainey joins (~ggainey@185.204.1.185)
2020-10-19 19:25:50 <hyperisco> going on a tangent… you need more sophisticated types than Haskell has (conveniently) on offer to have useful value inference
2020-10-19 19:26:36 × geowiesnot quits (~user@87-89-181-157.abo.bbox.fr) (Ping timeout: 256 seconds)
2020-10-19 19:26:37 × tomboy64 quits (~tomboy64@gateway/tor-sasl/tomboy64) (Remote host closed the connection)
2020-10-19 19:26:48 <monochrom> You know how people prefer following tangents than following direct relevant productive answers.
2020-10-19 19:27:17 → sfvm joins (~sfvm@37.228.215.148)
2020-10-19 19:27:25 × AceNovo quits (~chris@184.101.162.142) (Remote host closed the connection)
2020-10-19 19:28:04 <monochrom> The excitement of maximizing mysterious, uncertainty, adventures, and procrastinating actually solving the problem at hand.
2020-10-19 19:28:09 <hyperisco> well I am not sure what the thinking is, but if it is wondering why we have to still state values when the type is already known, it is a relevant point
2020-10-19 19:28:41 <monochrom> No, the question is why or when to state types.
2020-10-19 19:28:51 <hyperisco> there is no reason to assume Haskell's asymmetry of values and types if you have a fresh perspective
2020-10-19 19:29:39 <monochrom> phrased very unclearly, but it is still asking about when to omit types
2020-10-19 19:29:59 <monochrom> or when to legally omit types
2020-10-19 19:30:32 × ystael quits (~ystael@168.sub-174-196-209.myvzw.com) (Read error: Connection reset by peer)
2020-10-19 19:30:47 → thir joins (~thir@p200300f27f0b040039cda3b6fce8e5af.dip0.t-ipconnect.de)
2020-10-19 19:32:07 × conal quits (~conal@64.71.133.70) (Quit: Computer has gone to sleep.)
2020-10-19 19:33:43 → tomboy64 joins (~tomboy64@gateway/tor-sasl/tomboy64)
2020-10-19 19:33:54 → conal joins (~conal@64.71.133.70)
2020-10-19 19:35:54 → Pitaya joins (~mdomin45@cpe-24-211-129-187.nc.res.rr.com)
2020-10-19 19:36:22 × nineonine quits (~nineonine@216.81.48.202) (Remote host closed the connection)
2020-10-19 19:36:44 <crestfallen> very sorry, I don't know how to set @[] so the inference is known by ghci if pure is used
2020-10-19 19:37:30 <hyperisco> :t pure @[] -- what does ghci tell you when you do this?
2020-10-19 19:37:31 <lambdabot> error:
2020-10-19 19:37:32 <lambdabot> Pattern syntax in expression context: pure@[]
2020-10-19 19:37:32 <lambdabot> Did you mean to enable TypeApplications?
2020-10-19 19:37:46 <hyperisco> if it says that then you need to :set -XTypeApplications
2020-10-19 19:38:38 <crestfallen> that I get: it's a -> [a], which is a -> f a
2020-10-19 19:39:06 <hyperisco> those are not the same type
2020-10-19 19:39:06 <koz_> Do Vectors have something like itraverse?
2020-10-19 19:39:09 × Iwawa quits (~mdomin45@cpe-24-211-129-187.nc.res.rr.com) (Ping timeout: 258 seconds)
2020-10-19 19:39:24 <koz_> Like, something of type (Applicative f) => (Int -> a -> f b) -> Vector a -> f (Vector b)
2020-10-19 19:39:42 <crestfallen> sorry I meant pure :: Applicative f => a -> f a
2020-10-19 19:39:55 <crestfallen> the f is []
2020-10-19 19:40:18 <hyperisco> what is the problem?
2020-10-19 19:40:40 <hyperisco> are we having a confusion of variable scope
2020-10-19 19:41:06 <crestfallen> well I also read where ghci defaults to the f being IO or something
2020-10-19 19:41:09 <hyperisco> every use of pure has its own f
2020-10-19 19:41:21 → p-core joins (~Thunderbi@2001:718:1e03:5128:2ab7:7f35:48a1:8515)
2020-10-19 19:41:34 <hyperisco> in Haskell source you're used to seeing type variables not explicitly bound
2020-10-19 19:41:40 <hyperisco> pure :: Applicative f => a -> f a
2020-10-19 19:41:49 <hyperisco> what this means though is pure :: forall f a. Applicative f => a -> f a
2020-10-19 19:42:02 <hyperisco> every use of pure has its own f and a variables, they are bound by it
2020-10-19 19:42:19 <solonarv> koz_: if nothing else, lens has a typeclass for that indexed traversal and Vector is certainly an instance of it
2020-10-19 19:42:31 <hyperisco> :t (pure @[], pure @Maybe) -- for example
2020-10-19 19:42:32 <lambdabot> error:
2020-10-19 19:42:32 <lambdabot> Pattern syntax in expression context: pure@[]
2020-10-19 19:42:32 <lambdabot> Did you mean to enable TypeApplications?
2020-10-19 19:42:44 × kuribas quits (~user@ptr-25vy0i8tnjeny9qrt7n.18120a2.ip6.access.telenet.be) (Quit: ERC (IRC client for Emacs 26.3))
2020-10-19 19:42:55 <crestfallen> very sorry hyperisco but what about where we have the ((*),(+)). that is also part of what is being ascribed?
2020-10-19 19:43:06 <solonarv> koz_: oh! there is Data.Vector.imapM if you're okay with a Monad constraint rather than Applicativ
2020-10-19 19:43:16 <hyperisco> I don't know the discussion about that
2020-10-19 19:43:18 → nineonine joins (~nineonine@216-19-190-182.dyn.novuscom.net)
2020-10-19 19:43:31 × nineonine quits (~nineonine@216-19-190-182.dyn.novuscom.net) (Read error: Connection reset by peer)
2020-10-19 19:43:43 → nineonine joins (~nineonine@216-19-190-182.dyn.novuscom.net)
2020-10-19 19:44:04 <crestfallen> hyperisco: it's here, thanks http://ix.io/2BhD
2020-10-19 19:44:15 <koz_> solo
2020-10-19 19:44:21 <koz_> solonarv: That's fine.
2020-10-19 19:44:22 <hyperisco> saying pure @[] is like saying subtract 3 … you wouldn't expect that because you use subtract 3 once that everywhere then on that the first argument to subtract is set to 3
2020-10-19 19:44:46 <hyperisco> so is the same for pure @[] it isn't the case that f is set to [] then on for every use of pure, it only applies to the one use of pure
2020-10-19 19:46:36 × heatsink quits (~heatsink@107-136-5-69.lightspeed.sntcca.sbcglobal.net) (Remote host closed the connection)
2020-10-19 19:47:04 × nineonine quits (~nineonine@216-19-190-182.dyn.novuscom.net) (Remote host closed the connection)
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