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2020-10-20 06:54:26 → danvet joins (~danvet@2a02:168:57f4:0:5f80:650d:c6e6:3453)
2020-10-20 06:54:45 × isovector1 quits (~isovector@172.103.216.166) (Ping timeout: 240 seconds)
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2020-10-20 06:59:33 → fryguybob joins (~fryguybob@cpe-74-65-31-113.rochester.res.rr.com)
2020-10-20 06:59:33 <asheshambasta> Hi everyone, reflex-platform (?) related question. How does one override packages when using reflex-platform.project? I so far have: https://gist.github.com/asheshambasta/b18f21bc0bdf78b33b02cb846f4b83fe (based off https://github.com/srid/reflex-stone) where I'm trying to add the bulmex package.
2020-10-20 06:59:39 <asheshambasta> (I'm also using niv here)
2020-10-20 07:00:37 <asheshambasta> I can enter a nix-shell; but I get a "called without default argument "bulmex-custom"" error.
2020-10-20 07:01:48 <asheshambasta> (when firing up cabal; which has bulmex-custom as one of its dependencies.)
2020-10-20 07:03:17 → Echosolace joins (~Echosolac@p790105-ipngn4101hiraide.tochigi.ocn.ne.jp)
2020-10-20 07:03:48 × heatsink quits (~heatsink@107-136-5-69.lightspeed.sntcca.sbcglobal.net) (Remote host closed the connection)
2020-10-20 07:04:50 <Echosolace> Hey, newb here looking at sum . replicate 5 . max 6.7 $ 8.9
2020-10-20 07:05:00 <Echosolace> Can someone tell me if my understanding is correct?
2020-10-20 07:05:05 <Echosolace> It goes like this -
2020-10-20 07:05:07 → heatsink joins (~heatsink@107-136-5-69.lightspeed.sntcca.sbcglobal.net)
2020-10-20 07:05:23 × heatsink quits (~heatsink@107-136-5-69.lightspeed.sntcca.sbcglobal.net) (Remote host closed the connection)
2020-10-20 07:07:33 <Echosolace> max calls two parameters, so we are left with max 6.7 and a variable, let's call it a. It's a partial function, which is then called by replicate, which leaves us with a list that looks like this: [max 6.7 a, max 6.7 a, max 6.7 a, max 6.7 a, max 6.7 a]. Sum is called on that list, but now since a is undefined, it finally reaches out and replaces a with 8.9 and sums 5 x 8.9.
2020-10-20 07:08:47 × jedws quits (~jedws@121.209.161.98) (Quit: My MacBook has gone to sleep. ZZZzzz…)
2020-10-20 07:10:05 <merijn> Echosolace: Not really
2020-10-20 07:10:12 <Echosolace> Sigh*
2020-10-20 07:10:13 <suzu_> you have it backwards
2020-10-20 07:10:14 × Sgeo quits (~Sgeo@ool-18b982ad.dyn.optonline.net) (Read error: Connection reset by peer)
2020-10-20 07:10:22 <merijn> Echosolace: You are overthinking the partial application thing
2020-10-20 07:10:49 <merijn> Echosolace: Let's work backwards rewriting things
2020-10-20 07:10:54 <Echosolace> Ok
2020-10-20 07:11:00 <merijn> $ has the lowest precedence, so we start there
2020-10-20 07:11:08 <merijn> f $ x = f x
2020-10-20 07:11:09 <Echosolace> Yep. Everything to the left first.
2020-10-20 07:11:10 <merijn> So
2020-10-20 07:11:26 <merijn> (sum . replicate 5 . max 6.7) 8.9
2020-10-20 07:11:39 <Echosolace> Yes.
2020-10-20 07:11:40 × Plantain quits (~mdomin45@cpe-24-211-129-187.nc.res.rr.com) (Ping timeout: 272 seconds)
2020-10-20 07:11:51 <merijn> f . g = \x -> f (g x)
2020-10-20 07:12:15 <suzu_> the stuff in the braces is a function that gets called with 8.9
2020-10-20 07:12:19 <Echosolace> f of g
2020-10-20 07:12:23 <merijn> SO you get ((\x -> sum (replicate 5 x)) . max 6.7) 8.9
2020-10-20 07:13:07 <merijn> (\y -> (\x -> sum (replicate 5 x)) (max 6.7 y)) 8.9
2020-10-20 07:13:21 <merijn> Then we can simplify
2020-10-20 07:13:26 → Plantain joins (~mdomin45@cpe-24-211-129-187.nc.res.rr.com)
2020-10-20 07:13:43 <merijn> (\y -> sum (replicate 5 (max 6.7 y))) 8.9
2020-10-20 07:13:46 <merijn> And finally
2020-10-20 07:13:59 <merijn> sum (replicate 5 (max 6.7 8.9))
2020-10-20 07:15:17 → heatsink joins (~heatsink@107-136-5-69.lightspeed.sntcca.sbcglobal.net)
2020-10-20 07:15:18 <Echosolace> Ok ok I think that helped... The stuff in the braces is a function that gets called with the outside parameter... got it.
2020-10-20 07:15:31 <merijn> Although in practice you normally read "f . g . h" sorta like a pipeline where a values goes into 'h', it's result goes into 'g', and that result goes into 'f' (which, as you can see is exactly what happens in the elaborate version I wrote out
2020-10-20 07:16:08 <merijn> Without constructing all the lambda's in your head, because that's a load of bookkeeping
2020-10-20 07:16:15 <ghoulguy> I think it might help to rewrite (f.g.h) to (f.(g.h)) as an explicit step
2020-10-20 07:17:03 <merijn> Possibly, but I had was too lazy to figure out the brace and (fortunately) "f.(g.h)" and "(f.g).h" are the same ;)
2020-10-20 07:18:09 <ghoulguy> They end up being the same. I suppose it's convenient to collapse that all at once to \x->f(g(h x))
2020-10-20 07:18:48 → raichoo joins (~raichoo@213.240.178.58)
2020-10-20 07:18:58 <dminuoso> Mmm, can a generic function to provide isomorphisms between arbitrary tuples (that is `f :: (S,T,U) -> ((S,T),U)`, `f :: (S,T,U) -> (S,(T,U))`, `f :: ((S,T),U) -> (S,T,U)` exist at all?
2020-10-20 07:18:59 <merijn> Yeah, that's what my brain does, but that feels too much like "voodoo" for beginners, I think :)
2020-10-20 07:19:19 <merijn> I like dumb, mechanical rewrite rules, because anyone get understand them and they work really well in Haskell :)
2020-10-20 07:19:45 × heatsink quits (~heatsink@107-136-5-69.lightspeed.sntcca.sbcglobal.net) (Ping timeout: 240 seconds)
2020-10-20 07:19:54 × lpsmith quits (~lpsmith@unaffiliated/lpsmith) (Quit: ZNC 1.6.5 - http://znc.in)
2020-10-20 07:21:13 × Plantain quits (~mdomin45@cpe-24-211-129-187.nc.res.rr.com) (Ping timeout: 265 seconds)
2020-10-20 07:21:37 → lpsmith joins (~lpsmith@unaffiliated/lpsmith)
2020-10-20 07:22:15 → Plantain joins (~mdomin45@cpe-24-211-129-187.nc.res.rr.com)
2020-10-20 07:23:33 × tzh quits (~tzh@2601:448:c500:5300::e74c) (Quit: zzz)
2020-10-20 07:24:38 → SanchayanM joins (~Sanchayan@122.167.98.111)
2020-10-20 07:25:27 <Echosolace> Ok this one has been doing my head in for a couple of days. It seems so similiar to the previous one - replicate 100 . product . map (*3) . zipWith max [1,2,3,4,5] $ [4,5,6,7,8]
2020-10-20 07:25:49 × Sanchayan quits (~Sanchayan@106.200.207.22) (Ping timeout: 260 seconds)
2020-10-20 07:25:54 <Echosolace> So a lengthy function is being called on 4,5..8
2020-10-20 07:25:57 → heatsink joins (~heatsink@107-136-5-69.lightspeed.sntcca.sbcglobal.net)
2020-10-20 07:26:10 <Echosolace> max determines that 4,5..8 is bigger.
2020-10-20 07:26:20 <Echosolace> it's the zipWith that has me confused.
2020-10-20 07:26:27 <Echosolace> There's nothing to zipWith...
2020-10-20 07:26:42 <merijn> :t zipWith
2020-10-20 07:26:43 <lambdabot> (a -> b -> c) -> [a] -> [b] -> [c]
2020-10-20 07:26:53 <Echosolace> What...
2020-10-20 07:26:57 <Echosolace> :t zipWith
2020-10-20 07:26:57 <opqdonut> Echosolace: zipWith max [1,2,3,4] [4,5,6,7] ==> [max 1 4, max 2 5, max 3 6, max 4 7]
2020-10-20 07:26:59 <lambdabot> (a -> b -> c) -> [a] -> [b] -> [c]
2020-10-20 07:27:04 <Echosolace> Holy shit you can do that here?
2020-10-20 07:27:11 <merijn> Yes? :p
2020-10-20 07:27:17 <merijn> :t zipWith max
2020-10-20 07:27:18 <lambdabot> Ord c => [c] -> [c] -> [c]
2020-10-20 07:27:24 → thir joins (~thir@p200300f27f0b040039cda3b6fce8e5af.dip0.t-ipconnect.de)
2020-10-20 07:27:26 <Echosolace> wtf you can type multiples?
2020-10-20 07:27:36 <Echosolace> Yo.
2020-10-20 07:27:39 <merijn> Echosolace: The flaw in your reasoning is that max isn't being applied to those lists
2020-10-20 07:27:47 <merijn> zipWith is being applied to max
2020-10-20 07:28:14 <merijn> And then "zipWith max" is applied first to one list and then "zipWith max [1,2,3,4]" is applied to the final list
2020-10-20 07:29:02 <merijn> Echosolace: In general "foo bar baz quux" is parenthesised as "(((foo bar) baz) quux)"
2020-10-20 07:29:16 × howdoi quits (uid224@gateway/web/irccloud.com/x-ejhfdvhwhujhpzoz) (Quit: Connection closed for inactivity)
2020-10-20 07:29:26 <merijn> The exception is operator which are binary and *always* have lower precedence then function application
2020-10-20 07:30:12 <merijn> So "replicate 100 . product . map (*3) . zipWith max [1,2,3,4,5]" is "(replicate 100) . product . (map (*3)) . (zipWith max [1,2,3,4,5])"
2020-10-20 07:30:27 → avoandmayo joins (~textual@122-58-158-238-adsl.sparkbb.co.nz)
2020-10-20 07:30:34 × heatsink quits (~heatsink@107-136-5-69.lightspeed.sntcca.sbcglobal.net) (Ping timeout: 260 seconds)
2020-10-20 07:31:16 <merijn> > zipWith f [1,2,3,4] [5,6,7,8]
2020-10-20 07:31:18 <lambdabot> error:
2020-10-20 07:31:19 <lambdabot> • Ambiguous type variable ‘c0’ arising from a use of ‘show_M201622632345...
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