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| 2025-02-11 21:22:58 +0100 | <mauke> | which is why you can partially apply a type constructor like (->) and make a Functor instance for it |
| 2025-02-11 21:22:04 +0100 | <mauke> | perhaps non-obvious: you can curry type applications |
| 2025-02-11 21:22:03 +0100 | <monochrom> | BTW [a] = [] a |
| 2025-02-11 21:21:58 +0100 | <justsomeguy> | (By the way, I'm on 7% batter right now.) |
| 2025-02-11 21:21:49 +0100 | <mauke> | a -> b = (->) a b = ((->) a) b |
| 2025-02-11 21:21:47 +0100 | <monochrom> | Precisely why all of the above is correct. |
| 2025-02-11 21:21:29 +0100 | merijn | (~merijn@host-vr.cgnat-g.v4.dfn.nl) merijn |
| 2025-02-11 21:21:29 +0100 | <mauke> | yes |
| 2025-02-11 21:21:21 +0100 | <monochrom> | All true. |
| 2025-02-11 21:21:12 +0100 | <justsomeguy> | I'm not sure. Isn't (->) the type of a function, and e is the type of its first argument? |
| 2025-02-11 21:21:01 +0100 | JuanDaugherty | (~juan@user/JuanDaugherty) JuanDaugherty |
| 2025-02-11 21:20:07 +0100 | <mauke> | for example, do you know what (->) e means as a type? |
| 2025-02-11 21:19:56 +0100 | <mauke> | what's the first thing that makes no sense? |
| 2025-02-11 21:19:54 +0100 | <monochrom> | Write your own Functor instance for (->)e, and discover that its fmap is exactly (.) |
| 2025-02-11 21:19:50 +0100 | <mauke> | it wasn't very thoughtful :-) |
| 2025-02-11 21:19:17 +0100 | <justsomeguy> | Honestly, I wish I could say that I understood your thoughtful explanation, but I'm so confused. |
| 2025-02-11 21:15:51 +0100 | tromp | (~textual@92-110-219-57.cable.dynamic.v4.ziggo.nl) |
| 2025-02-11 21:14:23 +0100 | <mauke> | = (a -> b) -> (e -> a) -> (e -> b) |
| 2025-02-11 21:14:01 +0100 | <mauke> | let f = ((->) e) in (a -> b) -> f a -> f b ==> (a -> b) -> (->) e a -> (->) e b |
| 2025-02-11 21:12:57 +0100 | pavonia | (~user@user/siracusa) siracusa |
| 2025-02-11 21:12:53 +0100 | <lambdabot> | Functor f => (a -> b) -> f a -> f b |
| 2025-02-11 21:12:52 +0100 | <mauke> | :t fmap |
| 2025-02-11 21:10:52 +0100 | <mauke> | instance Functor ((->) e) where fmap = (.) |
| 2025-02-11 21:10:35 +0100 | merijn | (~merijn@host-vr.cgnat-g.v4.dfn.nl) (Ping timeout: 244 seconds) |
| 2025-02-11 21:10:28 +0100 | <mauke> | because fmap = (.) |
| 2025-02-11 21:10:23 +0100 | <justsomeguy> | How does fmap f Just = f . Just? |
| 2025-02-11 21:10:19 +0100 | <lambdabot> | Just 6 |
| 2025-02-11 21:10:18 +0100 | <mauke> | > fmap fmap fmap sum Just [1,2,3] |
| 2025-02-11 21:09:13 +0100 | <mauke> | the middle thing is where it gets funky |
| 2025-02-11 21:09:08 +0100 | <mauke> | the 1st/3rd things I said are just the definition of (.) |
| 2025-02-11 21:08:32 +0100 | <mauke> | (fmap sum . Just) [1,2,3] = fmap sum (Just [1,2,3]) |
| 2025-02-11 21:08:27 +0100 | <justsomeguy> | Wait wait wait... |
| 2025-02-11 21:08:04 +0100 | Katarushisu3 | Katarushisu |
| 2025-02-11 21:08:04 +0100 | Katarushisu | (~Katarushi@finc-20-b2-v4wan-169598-cust1799.vm7.cable.virginm.net) (Read error: Connection reset by peer) |
| 2025-02-11 21:08:01 +0100 | Katarushisu3 | (~Katarushi@finc-20-b2-v4wan-169598-cust1799.vm7.cable.virginm.net) Katarushisu |
| 2025-02-11 21:07:58 +0100 | <mauke> | because of the naked reader instance |
| 2025-02-11 21:07:52 +0100 | <mauke> | fmap f Just = f . Just |
| 2025-02-11 21:07:21 +0100 | <Rembane> | \o/ Functor laws \o/ |
| 2025-02-11 21:07:09 +0100 | <mauke> | (fmap . fmap) sum = fmap (fmap sum) |
| 2025-02-11 21:06:33 +0100 | <justsomeguy> | How does this evaluate: (fmap . fmap) sum Just [1,2,3]? Why does (fmap . fmap) sum Just [1,2,3] == (fmap sum) (Just [1,2,3])? |
| 2025-02-11 21:06:07 +0100 | merijn | (~merijn@host-vr.cgnat-g.v4.dfn.nl) merijn |
| 2025-02-11 21:04:17 +0100 | ljdarj1 | ljdarj |
| 2025-02-11 21:04:17 +0100 | ljdarj | (~Thunderbi@user/ljdarj) (Ping timeout: 252 seconds) |
| 2025-02-11 21:01:36 +0100 | <ash3en> | what is Fortan like, from the Haskell perspective? |
| 2025-02-11 21:00:45 +0100 | caconym | (~caconym@user/caconym) caconym |
| 2025-02-11 21:00:28 +0100 | ljdarj1 | (~Thunderbi@user/ljdarj) ljdarj |
| 2025-02-11 21:00:02 +0100 | caconym | (~caconym@user/caconym) (Quit: bye) |
| 2025-02-11 20:55:30 +0100 | merijn | (~merijn@host-vr.cgnat-g.v4.dfn.nl) (Ping timeout: 276 seconds) |
| 2025-02-11 20:55:00 +0100 | Katarushisu | (~Katarushi@finc-20-b2-v4wan-169598-cust1799.vm7.cable.virginm.net) Katarushisu |
| 2025-02-11 20:54:59 +0100 | ash3en | (~Thunderbi@2a03:7846:b6eb:101:93ac:a90a:da67:f207) ash3en |