#clojure – 2014-11-08

2014-11-08

00:15	rritoch	I'd love to switch to Mac but they're so overpriced, Lenovo Flex 2 (15-Inch) $700, Mac (15-inch) $2000, does Tin Cook really think we're that stupid?
00:16	justin_smith	there's offices full of people with office supplied macbooks saying yes
00:17	rritoch	I've noticed, many of my clients use Mac, I just don't get it
00:18	rritoch	My server with 4 Teraflops of computing power via 2 Radeon 280X's cost me less than that Macbook
00:22	rritoch	It was the first time I've seriously looked at Mac's in 25 years, not because Mac has improved, but because Microsoft has devolved.
00:26	catern	switch to Linux
00:26	catern	holy crap freenode spammers everywhere
00:26	catern	kickban kirloo, is spammer
00:29	rritoch	Well, I am running Ubuntu (rooted) on my server, but Linux still requires a lot of complex maintenance and configuration to set it up properly.
00:30	catern	that's not true
00:30	catern	also what
00:30	catern	Ubuntu (rooted), as in you have root?
00:30	catern	on a server you administrate, it would be highly unusual if you did not
00:30	catern	(have root)
00:30	justin_smith	if it was complex, would we really be using it on servers?
00:32	rritoch	justin_smith: Once it's configured it's stable for the most part, but getting the AMD drivers and OpenCL to work properly is a nightmare
00:32	justin_smith	rritoch: I bought this box with linux pre-installed. Compared to installing windows or mac from scratch it was a breeze to set up (but let's compare apples to apples - pre-installed to pre-installed, install from scratch to install from scratch)
00:32	rritoch	It still isn't working properly
00:32	rritoch	I can't get any video-out on the second video card
00:33	justin_smith	rritoch: as soon as I first powered up this machine I had full accelerated video
00:33	justin_smith	just like with a mac or windows box, the factory set it up for me
00:33	justin_smith	comapre apples to apples
00:33	rritoch	I can run dual screen on the one card, but if I connect screens to the second card they don't display anything
00:33	justin_smith	rritoch: I am using three screens right now, I can potentially use up to five, it just works
00:34	rritoch	From separate AMD cards?
00:34	justin_smith	one card
00:34	justin_smith	like I said, it was pre-configured by the folks who built my laptop
00:34	rritoch	multi-monitor works fine from my first video card, I just can't get any output on the second video card
00:34	justin_smith	just as your windows box was pre-configured by the folks who built your machine
00:35	rritoch	At least not from Linux, I have a dual-boot to windows and both cards function properly from windows
00:35	justin_smith	and who configured that? I expect it worked when you first bought the machine.
00:36	rritoch	It is a problem with the AMD catalyst driver, but I"m not sure what
00:36	rritoch	I configured it myself, it only came with Windows.
00:37	catern	rritoch: yes, but someone configured the Windows for you
00:37	rritoch	No, I just installed the Catalyst driver and it worked out of the box
00:39	catern	yes
00:39	catern	that's what we're saying
00:39	catern	anyway
00:40	rritoch	It worked on windows out of the box
00:40	rritoch	It doesn't work on Ubuntu out of the box
00:40	rritoch	that is what I"m saying
00:41	catern	yes, that's because someone already (mostly) configured it for you on Windows
00:41	catern	anyway
00:41	rritoch	Windows doesn't have any effect on linux in a dual-boot situation
00:41	catern	yes, justin_smith was just being competitive
00:42	justin_smith	catern: I just think it is unfair that people compare the experience installing an OS from scratch, to the experience with an OS that was pre-installed and pre-configured
00:42	catern	you seemed to be bashing Linux and praising Windows, so he was pointing out the seeming superiority of Windows in this regard is just a result of your laptop coming preinstalled and preconfigured with Windows
00:42	catern	justin_smith: i agree
00:43	justin_smith	"I tried to build a mercedes from parts, but just driving my kia is easier"
00:43	justin_smith	(an exageration, of course0
00:44	rritoch	justin_smith: I've installed windows from scratch literally hundreds of times, and linux from scratch dozens of times, windows is always easier to install.
00:44	rritoch	I suppose if you have garbage generic hardware linux is easy to use, but if you have good/modern hardware, linux is a nightmare.
00:45	catern	see justin_smith that's why you don't jump so far ahead in the conversation
00:45	rritoch	I have a 5th gen motherboard and 2X GPU's, so the setup was far from simple.
00:45	justin_smith	rritoch: I have a laptop with a top of the line video card that supports four simulaneous external displays, 32 gigs of ram installed, and 8 cores. The machine is over a year old but it is not trash.
00:46	rritoch	I can't compare any of this to Mac, as I said I haven't used an apple product in over 25 years, unless you count virtual machines, but I just used a prepared VM drive for that so I really don't know what the install is really like.
00:46	catern	well, anyway, on Windows you STILL have to look around for drivers, which is ridiculous, so Linux is superior there at least. you do have an unconventional setup so some configuration is to be expected
00:48	justin_smith	this is all pretty off topic, I'm sorry I went off like that.
00:48	rritoch	Well, clojure needs an OS, and needs a good one
00:49	rritoch	I wish oracle would bring back sparc, I bet clojure would run like a sportscar on a sparc server.
00:51	rritoch	I've been toying with the idea of a clojure OS, but I think that would be a brutal nightmare.
00:51	razum2um	is there any best practice to override map->MyRecord with a function with preconditions? or do I need to stick with another fn name?
00:51	justin_smith	razum2um: why override? just write your own and use it
00:52	justin_smith	don't steal the name, I think that would inevitably lead to confusion
00:52	razum2um	justin_smith: but ideally not about to override it, just add precondition
00:53	razum2um	ok, is there any semantic under fn* names, would it be ok for such cases?
00:54	justin_smith	razum2um: just write a function that validates the arguments and constructs the structure
00:56	razum2um	justin_smith: ok, but I think it good if such cases have traditionaly approved names, e.g. map->Record* means it behaves just like map->Record but may check args and fill in defaults
00:56	razum2um	i think convention over configuration is always good
00:56	justin_smith	there is no such tradition that I know of
00:57	justin_smith	adding a * at the end typically means "don't use this one"
00:57	justin_smith	see fn, let
00:57	razum2um	perhaps adding a bang will be good such in rails it means that fn may raise an exception
00:58	razum2um	but agian, I think absence of convention is very bad for understanding other's people code
00:58	justin_smith	razum2um: in clojure a bangh usually means that a function is not safe in a transaction, or it does some extreme mutation
00:59	razum2um	justin_smith: yeah, naming and cache invalidation are hard :)
00:59	justin_smith	,(clojure.string/join \space (filter (comp #(.endsWith % "!") name) (keys (ns-publics 'clojure.core))))
00:59	clojurebot	"vswap! vreset! set-error-mode! set-agent-send-executor! disj! conj! pop! compare-and-set! reset-meta! set-error-handler! set-agent-send-off-executor! dissoc! assoc! reset! alter-meta! persistent! run! set-validator! swap! volatile! io!"
01:00	razum2um	yes, they deal with mutation
01:01	razum2um	e.g. will you recognize map->>Record without looking into source of fn?
01:03	justin_smith	I would expect construct-Record or make-Record to do something that map->Record does not
01:09	razum2um	justin_smith: ok, but how you think, is there any sense to turn it and perhaps some other similar cases into a survey? just not to invent convention, but collaborately define it
01:16	rritoch	Does clojure provide any means of namespace inheritance? I'm thinking of changing the MVC framework I'm using to be more pure clojure (without the gen-class) but I'd like common functions available, like view-ns/render which can be overridden but have a default functionality "imported".
01:17	rritoch	My issue is that use/require doesn't actually "import" the functions into the current namespace, it just makes them available for use
01:26	akhudek	rritoch: you can refer either some of the symbols or all of the symbols when you require
01:26	razum2um	rritoch: I suggest to wirite a macro generating defn's which call original fn
01:26	akhudek	rritoch: or do you mean you want a copy essentially?
01:27	rritoch	Yes, I want a local copy, or better yet, reference
01:27	rritoch	Probably similar to what akhudek suggested
01:27	rritoch	But some means of bringing in all of the symbols
01:28	akhudek	e.g. you if you import into foo into namespace b, you want to be able to call it as b.foo
01:29	akhudek	I think there was a thread on the clojure list about that
01:29	akhudek	don’t remember any good solutions sadly
01:30	rritoch	Something like (map #(def (second %1)) (ns-publics 'some-other-ns))
01:31	rritoch	But of course it would need to be much cleaner than that, I suppose a macro could be used
01:32	godd2	I have (map #(vector %1 %2) (range 10) (range 10)) but I want to pass that second (range 10) -as the collection itself- to the anonymous function. Is there a way to stop map from sending the individual elements?
01:33	rritoch	I guess ... (map #(def (first %1) (second %1)) (ns-publics 'some-other-ns)) is closer though I don't think that would work... A macro may
01:37	rritoch	,(map #(vector %1 %2) (range 10) (take 5 (repeatedly #(range 10))))
01:37	clojurebot	([0 (0 1 2 3 4 ...)] [1 (0 1 2 3 4 ...)] [2 (0 1 2 3 4 ...)] [3 (0 1 2 3 4 ...)] [4 (0 1 2 3 4 ...)])
01:37	rritoch	godd2: Is that ok with you?
01:37	rritoch	err
01:37	rritoch	,(map #(vector %1 %2) (range 10) (take 10 (repeatedly #(range 10))))
01:37	clojurebot	([0 (0 1 2 3 4 ...)] [1 (0 1 2 3 4 ...)] [2 (0 1 2 3 4 ...)] [3 (0 1 2 3 4 ...)] [4 (0 1 2 3 4 ...)] ...)
01:37	TEttinger	tbaldridge: nice work with https://github.com/pixie-lang/pixie
01:41	godd2	yes! thank you rritoch
01:42	TEttinger	,(map (partial vector (range 10)) (range 10))
01:42	clojurebot	([(0 1 2 3 4 ...) 0] [(0 1 2 3 4 ...) 1] [(0 1 2 3 4 ...) 2] [(0 1 2 3 4 ...) 3] [(0 1 2 3 4 ...) 4] ...)
01:42	TEttinger	that does put it in reverse order though
01:43	godd2	TEttinger that will nicely produce the list rritoch made, but I wanted to pass the collection to the anon function so I could do more work on it
01:43	TEttinger	ah, ok
01:43	TEttinger	you can have it as a variable, or other bound name
01:45	TEttinger	,(let [roll (fn [] (repeatedly 5 #(rand-int 100)))] (map (partial vector (roll)) (range 10))
01:45	clojurebot	#<RuntimeException java.lang.RuntimeException: EOF while reading>
01:45	TEttinger	,(let [roll (fn [] (repeatedly 5 #(rand-int 100)))] (map (partial vector (roll)) (range 10)))
01:45	clojurebot	([(53 29 24 43 64) 0] [(53 29 24 43 64) 1] [(53 29 24 43 64) 2] [(53 29 24 43 64) 3] [(53 29 24 43 64) 4] ...)
01:45	TEttinger	weird
01:46	TEttinger	,(let [roll (fn [] (repeatedly 5 #(rand-int 100)))] (map #(vector % (roll)) (range 10)))
01:46	clojurebot	([0 (51 59 8 71 10)] [1 (45 46 53 29 55)] [2 (60 10 97 46 57)] [3 (67 78 25 26 55)] [4 (80 40 53 14 9)] ...)
01:48	godd2	awww I cant do repeated #() ??
01:48	lazybot	godd2: Uh, no. Why would you even ask?
01:48	rritoch	? It's repeatedly
01:49	godd2	sorry, nested
01:49	godd2	I can't do nested #()
01:50	rritoch	No but #() is just a reader macro, you can resort to an anony function via (fn [...] ....)
01:51	godd2	ah okay awesome
01:51	godd2	yay it worked! (map #(map (fn [x y] (vector x y)) %2 (repeat %1)) (range 10) (repeatedly #(range 10)))
01:51	godd2	I hope that's not an entirely stupid way of making a list of vector pairs of the cartesian product of (range 10) with itself
01:54	TEttinger	kinda
01:55	TEttinger	,(map #(map vector %2 (repeat %1)) (range 10) (repeatedly #(range 10)))
01:55	clojurebot	(([0 0] [1 0] [2 0] [3 0] [4 0] ...) ([0 1] [1 1] [2 1] [3 1] [4 1] ...) ([0 2] [1 2] [2 2] [3 2] [4 2] ...) ([0 3] [1 3] [2 3] [3 3] [4 3] ...) ([0 4] [1 4] [2 4] [3 4] [4 4] ...) ...)
01:56	godd2	I added (apply concat ...) to get rid of the list of lists
01:56	TEttinger	remember, fns are first-class in clojure, so (fn [x y] (vector x y)) is almost the same as vector
01:57	godd2	TEttinger but then I couldn't rely on map passing the elements of the colls from %2 and (repeat %1)
01:58	godd2	are you saying I could just pass (vector)
01:58	TEttinger	no
01:58	TEttinger	the function vector
01:58	TEttinger	like in the example I just posted
01:58	godd2	ahh okay I was making it more complicated than I needed to
01:59	godd2	,(apply concat (map #(map vector (repeat %1) %2) (range 10) (repeatedly #(range 10))))
01:59	clojurebot	([0 0] [0 1] [0 2] [0 3] [0 4] ...)
01:59	TEttinger	vector, instead of an anon fn calling vector, should be ever so slightly faster, and simpler to write
01:59	dbasch	&(for [x (range 10) y (range 10)] [x y])
01:59	lazybot	⇒ ([0 0] [0 1] [0 2] [0 3] [0 4] [0 5] [0 6] [0 7] [0 8] [0 9] [1 0] [1 1] [1 2] [1 3] [1 4] [1 5] [1 6] [1 7] [1 8] [1 9] [2 0] [2 1] [2 2] [2 3] [2 4] [2 5] [2 6] [2 7] [2 8] [2 9] [3 0] [3 1] [3 2] [3 3] [3 4] [3 5] [3 6] [3 7] [3 8] [3 9] [4 0] [4 1] [4 2] [4 3] [4... https://www.refheap.com/92893
01:59	TEttinger	and yeah, for is good for this :P
01:59	dbasch	^ godd2 is that what you want?
02:00	godd2	dbasch that is precisely what I wanted. Ill go look at the docs for for now, thank you!
02:04	rritoch	,(map-indexed (fn [x y] (map (partial #(vec (list %1 %2)) x) (range 10))) (range 10)
02:04	clojurebot	#<RuntimeException java.lang.RuntimeException: EOF while reading>
02:05	rritoch	,(map-indexed (fn [x y] (map (partial #(vec (list %1 %2)) x) (range 10))) (range 10))
02:05	clojurebot	(([0 0] [0 1] [0 2] [0 3] [0 4] ...) ([1 0] [1 1] [1 2] [1 3] [1 4] ...) ([2 0] [2 1] [2 2] [2 3] [2 4] ...) ([3 0] [3 1] [3 2] [3 3] [3 4] ...) ([4 0] [4 1] [4 2] [4 3] [4 4] ...) ...)
02:06	rritoch	,(map-indexed (fn [x y] (map (partial #(vec (list %1 %2)) x) (range 2))) (range 3))
02:06	clojurebot	(([0 0] [0 1]) ([1 0] [1 1]) ([2 0] [2 1]))
02:20	godd2	Here is the completed problem. Feel free to offer any criticism of the code, including format. https://gist.github.com/nicklink483/a7ad9968a9a58c7ebf0a
02:26	arrdem	Okay. Someone convince me to learn a structural editing mode for emacs
02:29	nonuby	is there a nil loving nth? rather than IOOB exceptipn
02:30	nonuby	ah nevermind 3rd arg is default not found, fits
02:33	rritoch	,(map #(seq (zipmap (range 10) (take 10 (repeatedly (partial identity %))))) (range 10))
02:33	clojurebot	(([0 0] [7 0] [1 0] [4 0] [6 0] ...) ([0 1] [7 1] [1 1] [4 1] [6 1] ...) ([0 2] [7 2] [1 2] [4 2] [6 2] ...) ([0 3] [7 3] [1 3] [4 3] [6 3] ...) ([0 4] [7 4] [1 4] [4 4] [6 4] ...) ...)
02:36	rritoch	Any ideas why that isn't sorted?
02:38	rritoch	,(map #(sort (zipmap (range 10) (take 10 (repeatedly (partial identity %))))) (range 10))
02:38	clojurebot	(([0 0] [1 0] [2 0] [3 0] [4 0] ...) ([0 1] [1 1] [2 1] [3 1] [4 1] ...) ([0 2] [1 2] [2 2] [3 2] [4 2] ...) ([0 3] [1 3] [2 3] [3 3] [4 3] ...) ([0 4] [1 4] [2 4] [3 4] [4 4] ...) ...)
02:40	TEttinger	(doc zipmap)
02:40	clojurebot	"([keys vals]); Returns a map with the keys mapped to the corresponding vals."
02:40	TEttinger	maps aren't sorted
02:42	TEttinger	,(map #(interleave (range 10) (repeat 10 %)) (range 10))
02:42	clojurebot	((0 0 1 0 2 ...) (0 1 1 1 2 ...) (0 2 1 2 2 ...) (0 3 1 3 2 ...) (0 4 1 4 2 ...) ...)
02:42	TEttinger	,(map #(map vector (range 10) (repeat 10 %)) (range 10))
02:42	clojurebot	(([0 0] [1 0] [2 0] [3 0] [4 0] ...) ([0 1] [1 1] [2 1] [3 1] [4 1] ...) ([0 2] [1 2] [2 2] [3 2] [4 2] ...) ([0 3] [1 3] [2 3] [3 3] [4 3] ...) ([0 4] [1 4] [2 4] [3 4] [4 4] ...) ...)
02:43	TEttinger	that closer to what you're after, rritoch?
02:43	rritoch	I see, I just assumed they maintained the order items were added to them. Scary how many bugs may be floating around because of that mistake.
02:43	TEttinger	maps are never sorted by default, you can use the collections in a lib called "ordered" if you want the behavior you describe
02:44	rritoch	I actually don't have use with this code, I was just playing with the different ways of creating a matrix of positional vectors
02:44	godd2	in (reduce conj () "hello") is the 'magic' that reduce is treating "hello" like a sequence of characters?
02:44	TEttinger	there is the sorted-map , and you can also do sorted-map-by
02:44	TEttinger	yes
02:45	TEttinger	strings can be treated as seqs by most core clojure fns
02:45	TEttinger	they aren't actually seqs but they can be used as such
02:46	TEttinger	,(reduce str "hello " "world")
02:46	clojurebot	"hello world"
02:46	TEttinger	##(reductions str "hello " "world") ;; let's see how this works
02:46	lazybot	⇒ ("hello " "hello w" "hello wo" "hello wor" "hello worl" "hello world")
02:49	godd2	okay cool
02:50	TEttinger	godd2, you'll probably enjoy learning about destructuring, if you haven't already
02:50	TEttinger	it's one of the cooler features clojure has in regards to cleaning up code
02:51	godd2	I have learned about destructuring. I haven't tried it out with all the different types and such, but I do know how to, say, pass a vector as if its elements were the parameters
02:52	godd2	I come from a Ruby background, and destructuring seemed similar to passing arrays to methods and having individual params take on the elements themselves by default
02:54	godd2	But I'm trying to learn Clojure without trying to do things the Ruby way
02:58	TEttinger	it does seem like a lot of people come to clojure from the ruby community. both are concise, expressive languages, certainly, with a focus on getting stuff done.
02:59	godd2	Even in Rich's talks you'll see various examples of things which include Ruby in the list
03:07	godd2	ooooh, I like this ->> thingy
03:07	arrdem	-> and ->> are awesome
03:07	arrdem	factor of at least four readability increase once I got used to it
03:13	sam122	Hi, I'd like to contribute to Clojure and hopefully try out for gsoc 2015. Is it too late to start?
03:13	sam122	And how much knowledge of Clojure is required?
03:14	godd2	sam122 when you say "contribute to Clojure" do you mean Clojure itself, or something that happens to be written in Clojure?
03:15	sam122	Clojure, Typed Clojure etc
03:16	godd2	Is this a good way of formatting? https://gist.github.com/nicklink483/65b1801b00e7e0bfb816
03:16	arrdem	Speaking as an ex-gsoc student, getting changes into clojure/core itself is basically impossible unless you are actually Rich
03:16	arrdem	that said anyone can propose changes with no background
03:16	arrdem	it's just that Rich'll take only what he likes
03:16	arrdem	contributing to clojure.* is easy tho
03:17	godd2	Also, is there a go-to format guide for writing Clojure?
03:17	arrdem	ambrosebs, the core.typed maintainer and the other contrib libraries are awesome to a man
03:17	arrdem	godd2: there is a community style guide
03:17	arrdem	$google clojure style guide
03:17	lazybot	[bbatsov/clojure-style-guide · GitHub] https://github.com/bbatsov/clojure-style-guide
03:18	arrdem	there's also Eastwood, which tries to lint for unidiomatic code,
03:18	arrdem	but form the most part formatting isn't standardized
03:18	godd2	alright, thank you
03:19	arrdem	godd2: functions on the same line as arguments, arguments broken by line only when you'd go over 80 or it'd be detrimental to readability.
03:19	arrdem	godd2: the = and seq/reverse here
03:19	arrdem	godd2: otherwise looks fine
03:19	sam122	Would a basic knowledge be sufficient?
03:19	nonuby	i have this in my project.clj https://www.refheap.com/92897 yet running lein with-profile couchexport uberjar still produces project name version (e.g. ncdoffice-0.0.2-snapshot.jar) and not couchexport.jar, any ideas?
03:20	arrdem	sam122: well you have to convince a maintainer or two to support you for GSoC... so prior experience/interest is a huge help
03:20	sam122	Ok :)
03:20	sam122	Thanks!
03:21	sam122	I hope there are more slots in 2015.
03:22	arrdem	shrug. find something to work on and seriously put some time into it ahead of time. I wouldn't say that getting accepted to GSoC is a horribly high bar for Clojure
03:22	arrdem	not that we've had a slack project I know of so... shrug
03:51	wildharvest	I'm stuck on problem #22 on 4clojure, counting a sequence without using count. It's saying I tripped the alarm when I haven't used count.
03:52	wildharvest	I'm assuming its a macro thing, but I'm not sure if its a bug or if my solution is wrong
03:55	TEttinger	,(reduce (fn [c _] (inc c)) 0 [1 2 3])
03:55	clojurebot	3
03:55	TEttinger	what's your solution so far, wildharvest?
03:56	wildharvest	My solution was (fn [s] (let [r 0] (doseq [i s] (swap! r inc)) r))
03:57	TEttinger	well, swap! only works on atoms
03:58	TEttinger	so since r is a number, it wouldn't run anyway
03:58	arrdem	do you really need mutability here?
03:58	arrdem	^ always ask this in Clojure
04:01	wildharvest	I knew I was headed in the wrong direction with swap! but wasn't quite sure how to do it with filter/reduce/map but your solution cleared that up for me
04:03	wildharvest	Thanks TEttinger & arrdem
04:03	TEttinger	no prob
04:03	arrdem	my pleasure
04:04	arrdem	I'll be here, with beer, telling you to do it better all night :P
04:41	ingsoc	anyone use counterclockwise, I am wondering how you can get the saved changes immediately reflected in the integrated REPL - save + load
04:43	amalloy	arrdem: another thing to always reconsider: whether you really need the integer indices of a seq
04:44	ingsoc	CTRLK+ALT+K seems to compile into REPL window
05:15	crocket	Does clojure suffer java's null pointers?
05:17	amalloy	basically
05:18	borkdude	crocket yes, but you can use core.typed to prevent some
05:19	crocket	JAva libraries throw NPEs which clojure can't prevent.
05:19	borkdude	crocket most NPEs will come from interop code. Clojure's composable functions and datastructures cope with nil in a sane way.
05:19	TEttinger	also, many of clojure's core functions handle nil better.
05:19	crocket	Can programmers write clojure codes that throw NPEs not because of java libraries?
05:19	TEttinger	,(map inc nil)
05:19	clojurebot	()
05:20	TEttinger	crocket: of course
05:20	TEttinger	,(+ 1 nil)
05:20	clojurebot	#<NullPointerException java.lang.NullPointerException>
05:20	crocket	nil == null?
05:20	TEttinger	yes, in clojure
05:20	borkdude	,(throw (NullPointerException.))
05:20	clojurebot	#<NullPointerException java.lang.NullPointerException>
05:20	crocket	That's no good
05:20	crocket	null is a mistake.
05:21	borkdude	crocket maybe you can try Haskell then ;)
05:21	TEttinger	not having nil would mean clojure couldn't use any java libs, which would be a worse mistake
05:22	crocket	What about clojurescript?
05:22	borkdude	crocket same thing
05:22	crocket	null in javascript is different from null in java.
05:22	TEttinger	javascript also has the concept of null, yeah
05:23	borkdude	crocket Crockford said that he only uses undefined and not null
05:23	TEttinger	you of course won't get NPE in clojurescript because that's an error defined on the Java VM
05:23	TEttinger	(technically, maybe you could if you mis-wrote a macro, but it would show up at compile time)
05:24	TEttinger	there's probably something similar in JS, though I wouldn't know what it is
05:24	crocket	javascript doesn't have NPE.
05:25	crocket	clojure looks amusing to my eyes.
05:25	crocket	JAva is too verbose.
05:25	crocket	Clojure seems to beat scala on JVM.
05:25	borkdude	crocket it is very amusing and also addicting
05:25	TEttinger	crocket, yeah, agreed about scala
05:25	crocket	Scala is becoming the next C++.
05:25	TEttinger	scala is a very large language that suffers from bloat yes
05:26	crocket	Yet, scala still has some advantages.
05:26	TEttinger	clojurescript's macros are done in clojure in the process of generating the javascript, and the clojure part of the compiler is on the JVM, so that's the only place CLJS can technically throw NPEs, at compile-time
05:27	TEttinger	never in production, which is nice
05:28	TEttinger	clojure is definitely a very succinct language, short code is common where in java it would be many lines
05:28	crocket	A fellow programmer at my company showed how beautiful clojure was compared to javascript and java.
05:29	crocket	Yet, there is one doubt.
05:29	crocket	When coding in nodejs, I needed a lot of documentations.
05:29	crocket	Do I need a lot of documenatations due to dynamic nature?
05:29	crocket	Do I need a lot of documenatations due to dynamic nature in clojure?
05:30	TEttinger	the docs are good, certainly, and there's a lot of effort to improve them further
05:30	TEttinger	once you know the core functions in the standard lib, there's a lot less to look up
05:31	crocket	TEttinger, no
05:31	crocket	I want to know if the dynamic nature of clojure requires me to attach a lot of documentations to my code.
05:31	crocket	ok
05:31	crocket	In nodejs, there was no standardized way to document codes.
05:31	crocket	because static analysis fails.
05:31	TEttinger	well if you're working with other programmers, they would appreciate docs. there is a standard here
05:32	crocket	JSDoc fails to document JS codes.
05:32	crocket	No single document lib documents JS codes well.
05:34	TEttinger	,(defn map-indexed-2 "Runs function f on the first elements of coll1 and coll2, passing the index as the first argument, then the second elements, etc." [f coll1 coll2] (map f (range) coll1 coll2))
05:34	clojurebot	#'sandbox/map-indexed-2
05:34	TEttinger	,(doc map-indexed-2)
05:34	clojurebot	"([f coll1 coll2]); Runs function f on the first elements of coll1 and coll2, passing the index as the first argument, then the second elements, etc."
05:35	ingsoc	my first impressions of clojure (an hour or so) are that the tooling leiningen and counterclockwise(eclipse plugin) are very nice and this is my first lisp and although early days I am findign the whole environment more approachable than Ocaml (which I dipped my toes into yesterday), also I like the python style documentation for functions - dosctrings?
05:35	TEttinger	,(map-indexed-2 + [0 100 200 300] [0 10 20 30])
05:35	clojurebot	(0 111 222 333)
05:36	TEttinger	ingsoc, yep, docstrings are nice
05:36	crocket	OCaml
05:36	crocket	The razor of Ocaml
05:36	crocket	oops
05:36	TEttinger	Occam's razor?
05:36	crocket	It's Ocam's razor.
05:38	TEttinger	OCaml is a strongly typed functional language with a very good, but very strict, compiler. technomancy wrote a faster-starting substitute for part of leiningen in OCaml, called Grenchman IIRC
05:38	TEttinger	one of the cool things OCaml can do is debug in reverse
05:39	TEttinger	not many libs for OCaml though
05:40	rritoch	Does clojure use any classloaders other than the thread's context class loader and Compiler/LOADER ?
05:40	ingsoc	well i haven't abandoned trying Ocaml, I just had a few problems early on. I had shortlisted Ocaml or Clojure to learn as a next language
05:40	TEttinger	clojure has more momentum, I'd say
05:41	TEttinger	it's definitely advancing into some rarely-found features, like the "transducers" being introduced with clojure 1.7
05:41	TEttinger	core.async I have heard good things about
05:44	rritoch	I setup the following function to call methods on OSGi services http://pastebin.com/b7shFxXK but I'm not sure if there are any other classloaders I need to override.
05:50	ingsoc	TEttinger: the main thing that puts me off clojure is JVM being a big beast (slow startup), but on the plus side it means it has access to all of the java ecosystem. Ocaml is much lighter weight in this regard and it also has pattern matching which I have really enjoyed in erlang.
05:57	TEttinger	ingsoc, I've been curious about a new project called Pixie that runs a clojure-like lisp on PyPy's VM
05:57	TEttinger	I'm not sure if it can call python code yet https://github.com/pixie-lang/pixie
05:58	TEttinger	but it does get fast startup times from that VM
05:58	TEttinger	tbaldridge is likely asleep, but he's the guy to ask
06:24	massi`	hello *
06:27	annelies	hello
06:51	godd2	is there a way to not print the next return value in lein repl?
06:56	hyPiRion	godd2: I usually do `(do (my-expr) nil)` to print nil instead
06:57	hyPiRion	,(map #(throw (Exception. %)) ["foo"])
06:57	clojurebot	#<Exception java.lang.Exception: foo>
06:57	hyPiRion	,(do (map #(throw (Exception. %)) ["foo"]) nil)
06:57	clojurebot	nil
06:58	godd2	okay cool, thanks
07:09	godd2	Is there a reason that leiningen won't claim more than 4 to 4.5 GB of ram?
07:10	annelies	Running a 32-bit JVM?
07:11	godd2	"Java HotSpot(TM) 64-Bit Server VM 1.7.0-b147" when lein repl starts up
07:12	annelies	What is the value of :jvm-opts in project.clj?
07:13	godd2	That key isn't in the project.clj that boots with that repl
07:13	godd2	its just the default project file from lein new app
07:14	godd2	it's not a big deal, I was just somewhat curious.
07:16	rritoch	,(.maxMemory (Runtime/getRuntime))
07:16	clojurebot	#<CompilerException java.lang.SecurityException: Reference To Runtime is not allowed, compiling:(NO_SOURCE_PATH:0:0)>
07:17	rritoch	godd2: I suspect it has something to do with that, I have 8GB ram, but my max memory is 2GB
07:18	annelies	I have 4GB and maxMemory returns 1GB.
07:20	godd2	ah okay got it. I did the maxMemory thing before and after adding :jvm-opts ["-Xmx12G"] to the project file and got 3.5 GB before and ~10.8 GB after
07:21	annelies	GB vs GiB perhaps.
07:22	godd2	yes /GB/GiB/g
07:22	godd2	I divided by 1024^3
07:23	godd2	awesome, thanks guys. I super promise not to thoughtlessly set max ram higher :P
07:25	annelies	I wish I wrote software where memory limits were actually a thing. :(
07:27	godd2	Oh I was just messing around in Clojure. apparently (reduce + (take 40000000 (range))) takes up around 5 gigs once it's finished
07:27	Bronsa	godd2: (take n (range)) is just (range n) btw
07:28	annelies	There is an O(1) algorithm to do that. :p
07:28	annelies	sum of integer range
07:28	godd2	n * (n+1) / 2 I know
07:28	godd2	I just wanted to see how far Clojure would dutifully be persistent along the way
07:29	hyPiRion	godd2: huh, that shouldn't take 5 gigs
07:31	godd2	hyPiRion You're right, sorry. I did a (def a (take 40000000 (range))) and then (reduce + a) on a new line
07:31	hyPiRion	I'm not able to reproduce that with (reduce + (range 40000000)) actually
07:31	hyPiRion	ah, right
07:31	hyPiRion	yeah, if you retain the head, you're going to have a bad time. But if you don't, then it should either store 1 or 32 elements only
07:32	godd2	because of the lazy eval of range?
07:32	hyPiRion	yup
07:34	ingsoc	TEttinger: "transducers" ?, also i hear protocols are raved about but i don't know much about them are they kinda like interfaces
07:35	godd2	ingsoc: https://www.youtube.com/watch?v=6mTbuzafcII
07:35	hyPiRion	ingsoc: protocols are like interfaces, but unlike interfaces, you can implement the protocol outside the record/class
07:36	hyPiRion	this means if I have a protocol P in lib A, and a record R in lib B, and that I can implement the protocol for R in my app without changing lib B
07:36	ingsoc	Rich Hickey's hair gets wilder
07:37	ingsoc	:D
07:37	SagiCZ1	ingsoc: i just wanted to say that
07:38	godd2	"As time goes on his hair just gets better and better." - top comment from reddit thread of that video
07:38	ingsoc	Brian May
07:39	godd2	It reminds me of Steven Pinker's hair
07:39	ingsoc	Hair proportional to features ?
07:40	godd2	Hickey might be able to join The Luxuriant Flowing Hair Club for Scientists
07:41	ingsoc	Isaac Newton had a fair barnet on him also :)
07:44	ingsoc	how come clojure is so fast even with it appearing to be so dynamic ? Is this just testament to the power of JVM JIT etc. ?
07:46	Lowl3v3l	ingsoc, i believe it is primarily, yes.
07:47	ingsoc	I know you shouldn't choose a language because of the tooling counterclockwise for eclipse and leiningen are just making clojure so much easier to use than Ocaml (I don't use or have the time to invest in learning Emacs)
07:47	Lowl3v3l	ingsoc, you should take the time, it is worth.
07:50	SagiCZ1	ingsoc: but eclipse is so horrible i cant imagine any sane person could use it
07:50	ingsoc	Lowl3v3l: I have heard this a lot
07:50	ingsoc	I have also heard that a lot
07:50	ingsoc	:D
07:50	SagiCZ1	http://www.ihateeclipse.com/
07:51	ingsoc	eclipse appears overwhelmingly complex (considering most people just want to code in an editor)
07:51	ingsoc	but I kinda forced myself to use it (not knowing any better) and I spose now I know my way around it i like it
07:51	ingsoc	:/
07:52	SagiCZ1	ingsoc: i dont think its complex, but its bloated, buggy and incredibly slow
07:52	ingsoc	version 4+ is ridiculously slow on linux atm
07:52	ingsoc	3.7 works fine
07:53	ingsoc	I code in isolation and have never been exposed to Emacs to "see the light"
07:53	ingsoc	maybe I will have a look one day
07:53	SagiCZ1	ingsoc: see intellij if you want a good ide for java and cant cope with emacs
07:54	ingsoc	SagiCZ1: I use intellij (Webstorm) for web dev
07:54	annelies	I once wrote a function that returned whether an editor is good or not.
07:54	ingsoc	and I like it
07:54	ingsoc	I use eclipse for python and erlang - at the time if I wanted an IDE for erlang it was the only resonably mature option
07:54	annelies	It was (partial contains? #{:emacs :vim})
07:55	ingsoc	:)
07:55	SagiCZ1	ingsoc: alright, cant believe you can still go back to eclipse.. its so bad :D
07:55	ingsoc	I would NOT be able to code for the web now without Webstorm
07:56	godd2	never heard of it. what's webstorm?
07:56	annelies	IntelliJ specialised for client-side web dev.
07:57	godd2	ah okay
07:57	ingsoc	godd2: from the intelliJ IDE guys (Jetbrains)
07:57	SagiCZ1	annelies: well i cant say that vim or emacs is bad, but it was just too much to learn new language (clojure) and a completely new editor (emacs)
07:58	ingsoc	It is focussed for web dev and at the time i didn;t want to have all the other features confusing the IDE (like what happens with eclipse with all its different "perspectives")
07:59	ingsoc	not sure if thre is an intelliJ/Webstorm plguin for clojurescript though yet
07:59	ingsoc	plugin*
07:59	SagiCZ1	ingsoc: i still distinctly remember the wtf moment i experienced when trying to turn debugging on in eclipse..
08:00	SagiCZ1	ingsoc: there is Cursive
08:00	SagiCZ1	ingsoc: https://cursiveclojure.com/
08:00	SagiCZ1	it is amazing
08:01	m1dnight	ugh, i've about had it with emacs and cider
08:01	m1dnight	thing randomly "cant find file on classpath"
08:01	ingsoc	anyone using lightable
08:01	Lowl3v3l	SagiCZ1, is cursive ready to use yet?
08:01	ingsoc	light table*
08:02	ingsoc	the demos show some great promise, looks to be implementing Bret Victors demo of an interactive IDE
08:04	SagiCZ1	Lowl3v3l: its not finished, but i use it every day without a problem
08:04	annelies	What'd you call (fn [& fs] (apply comp (reverse fs)))? pmoc?
08:04	ingsoc	http://vimeo.com/36579366 skip to 16:45 and see how he interactively develops binary search
08:04	Lowl3v3l	SagiCZ1, to sad i do not like non-open-source products
08:04	ingsoc	apparently that kind of thing is avaiulable in light table for clojure
08:05	annelies	May be better to use #(-> % ...) though I guess.
08:05	SagiCZ1	Lowl3v3l: yeah... ive seen how open source eclipse is great.. i would rather pay a couple $$ for a good editor than tear my hair
08:06	Lowl3v3l	SagiCZ1, well. Emacs is Open Source and i like it. Vim too.
08:07	SagiCZ1	Lowl3v3l: yeah, but those are decades old.. i guess they are polished now
08:07	Lowl3v3l	SagiCZ1, and they are still good. I just don't like closed source in general^^
08:07	SagiCZ1	Lowl3v3l: i understand
08:13	ingsoc	so what language did you guys use prior to clojure ?, are there a lot of java converts or from totally different environment (non JVM)
08:13	SagiCZ1	ingsoc: for me it was mostly Java
08:14	Lowl3v3l	i use a whole couple of languages upt to now, clojure isn't even my only lisp^^
08:14	SagiCZ1	yeah i actually had a brief episode with Common Lisp before discovering Clojure
08:14	ingsoc	SagiCZ1: it looks WAY more concise than Java so I am guessing for you clojure has been a productivity enhancer
08:14	ingsoc	ok
08:15	ingsoc	a guy at a local tech meetup keeps telling me how clojure changed his views on programming and loves it keeps asking me to try it, I do the same to him but with erlang
08:15	SagiCZ1	ingsoc: definitely, the only gripe with clojure i have, is not understanding it as much as i understand java, so some things which should be quicker and easier to do in clojure are actually harder.. but i am getting there
08:15	ingsoc	:)
08:17	ingsoc	my concern with clojure is do i inevitably have to learn java to become truly competent. I know I am comparing apples and oranges a bit here but I use coffeescript but in the end I had to know javascript to use it effectively
08:17	godd2	same coming from Ruby. everything looks out of order...
08:17	hyPiRion	I started out with Java/Common Lisp. Really hard to understand how to do purely functional programming in the beginning, but with experience that feels superior in many cases.
08:17	hyPiRion	Guess coming from Erlang makes that transition a bit easier
08:17	SagiCZ1	ingsoc: i am not sure you would have to know java, but it might help a lot
08:18	hyPiRion	ingsoc: Can't speak for Clojure/Java, but I don't know JavaScript properly and managed to create rather "sophisticated" ClojureScript programs
08:19	godd2	But I have found a couple amazing Clojure tutorials. http://www.braveclojure.com/getting-started/ for text (you can skip the emacs part if you don't emacs) and for video: https://www.youtube.com/watch?v=9A9qsaZZefw&list=PLAC43CFB134E85266
08:19	hyPiRion	As long as you find non-Java libraries for the things you want to do, life should be easy without Java knowledge.
08:19	ingsoc	hyPiRion: yeah, erlang was originally a bit painful as it was my first ever functional language. No loops (only recursion), single assignment, no objects or global anything etc.
08:20	ingsoc	big shift, but now i find it a better way to structure programs
08:20	ingsoc	seems to force you down the path of divide and conquer with small independent easily understood functional components
08:21	SagiCZ1	ingsoc: i guess thats a common experience with most functional languages.. it is hard at the beginning but you can appreciate it later.. especially testing just seems so easy compared to java mutant world
08:21	ingsoc	hyPiRion: I am hoping to try clojurescript at some point as I still haven't found a nice language for client side web dev yet. Coffeecript is a nicer face to JS but it is still quite fragile
08:23	Lowl3v3l	SagiCZ1, there is a reason why i prefer teaching with functional languages.
08:23	hyPiRion	Leaky abstractions, eh
08:23	Lowl3v3l	i believe in general functional programming is, for someone who didn't program before, easier
08:24	SagiCZ1	Lowl3v3l: i am not sure.. maybe for mathematcians.. imperative programming is easy because it is just a sequence of steps.. the computer follows it like a cooking recipe
08:24	ingsoc	one problem I find people have is recursion, it seems some people have real trouble visualising in their minds eye what is occurring
08:25	SagiCZ1	ingsoc: it is definitely not trivial.. especially trying to visualize the call stack
08:25	godd2	Some otherwise imperative languages offer recursive tools, so it's not all bad depending on the transition
08:25	Lowl3v3l	the problem is that imperative programming allows for constructs like x = x+1; which is kind of absurd if you think about it^^
08:25	ingsoc	actually, do you have to be mindful in clojure of the stack or is there tail call optimisations like in erlang/Ocaml
08:26	Lowl3v3l	ingsoc, there is a possibility for tail calls
08:26	SagiCZ1	there are ONLY tail recursions in clojure, right?
08:26	godd2	SagiCZ1 yes but not all tail recursions are tco'd
08:26	SagiCZ1	godd2: i see
08:27	godd2	at least, that's my understanding
08:27	Lowl3v3l	well no. There is recur.
08:27	ingsoc	tco means that the compiler/runtime knows that to continue next recursion it doesn't need to push anything else onto stack ?
08:27	Lowl3v3l	But in general you could write a non-tail-recursion by directly calling a function generating a stack overflow with enough calls
08:28	SagiCZ1	does functional programming imply immutable data?
08:30	godd2	SagiCZ1 not necessarily. in Clojure you can tap into java data structures which are mutable
08:30	ingsoc	SagiCZ1: my understanding is that immutable data is a key trait of functional language
08:30	Lowl3v3l	SagiCZ1, depends on. There is up to my mind at least the theoretical possibility to do it without by not using the von-neumann-architecture... But practical i believe so.
08:30	godd2	SagiCZ1 there'
08:31	godd2	SagiCZ1 there's also the difference between "pure" functional and functional. a "pure" function never returns anything different given some inputs
08:31	Lowl3v3l	godd2, well, but foing that you leave the functional space, don't you? Functional means side-effect-free which is why clojure isn't strictly functional in the sense haskell, for example, is.
08:31	SagiCZ1	godd2: i wasnt talking about clojure specifically.. its possible to write a clearly imperative code in clojure.. if you use atoms and mutate states of java objects using interop.. but it is still a functional language
08:32	godd2	SagiCZ1 right, Clojure doesn't restrict you from not being functional, but if you want to be funcitonal, it provides every opportunity
08:32	SagiCZ1	godd2: i see your point
08:52	oskarkv	Hm, what is going on here? https://www.refheap.com/919221bb6a9664a3485c8cb01
08:53	oskarkv	Oh, literals...
08:56	justin_smith	oskarkv: looks like you should just match on PRIMARY / SECONDARY / MIDDLE I guess?
08:56	justin_smith	I haven't tried matching enums in a case before
09:01	justin_smith	,(case java.time.format.FormatStyle/FULL FULL :true LONG nil MEDIUM nil SHORT nil)
09:01	clojurebot	#<CompilerException java.lang.ClassNotFoundException: java.time.format.FormatStyle, compiling:(NO_SOURCE_PATH:0:0)>
09:01	justin_smith	oh, new in 1.8, duh
09:02	justin_smith	anyway, yeah, it seems there is no way to match on an enum (none I could figure out, at least)
09:03	oskarkv	justin_smith "The test-constants are not evaluated." So I guess Class/Something is just a symbol in the case
09:03	justin_smith	hmm
09:03	justin_smith	yeah, I guess so, I thought the reader did that, but OK
09:03	justin_smith	oh right, the reader could not do that
09:10	ingsoc	hmmm, jobs in UK are pretty thin on the ground for clojure devs . Maybe people wanting to use clojure get java jobs and introduce clojure into their workplace
09:10	ingsoc	(not that I care about popularity but it would be interesting to know if clojure IS getting more popular in industry)
09:11	annelies	Where is the transducer library?
09:11	annelies	I cannot find the functions mentioned in the talk on this page: http://clojure.github.io/clojure/
09:12	SagiCZ1	~lazy-logs
09:12	clojurebot	lazy-logs is http://logs.lazybot.org/
09:14	SagiCZ1	ingsoc: if you want a language that is widely used and get a job with it, java is the surest way to go.. there is just so many java jobs its mind boggling.. i was looking for a java job and was employed within 5 days
09:14	Glenjamin	is anyone else seeing all the gravatars missing on github.com?
09:15	AeroNotix	Glenjamin: force refresh
09:15	Glenjamin	seems like github itself is now breaking anyway
09:15	Glenjamin	all the graphs on https://status.github.com/ just shot up
09:16	ingsoc	SagiCZ1: I was just curious as to whether clojure is becoming an employable skill and popularity increasing or has it topped out
09:16	Glenjamin	ingsoc: where in the UK are you looking?
09:17	Glenjamin	i know thoughtworks are pushing Clojure quite a bit, and there's some GDS stuff thats starting to use it
09:18	AeroNotix	uswitch are big clojure users
09:18	AeroNotix	in the UK
09:18	Glenjamin	i think mail online do a bunch of clojure as well
09:19	ingsoc	Glenjamin: currently in Manchester, and I have been to some of the their tech talks. I was just curious as to the general trend of whether companies are seeing the benefits of moving away from traditional languages like java/.net for greenfield projects
09:19	AeroNotix	The Guardian do a bit here n there, though mainly Scala.
09:20	ingsoc	Scala seems overly complicated
09:20	AeroNotix	ingsoc: you should look at the financial sector in London
09:20	Glenjamin	ingsoc: outside of London i mostly see companies playing it safe with PHP/Java/.net/Python/Ruby
09:20	ingsoc	yeah, erlang seems popular in London too in finance
09:20	Glenjamin	and really, who wants to go live in London?
09:20	ingsoc	yeah exactly
09:20	AeroNotix	meh, rough with the smooth
09:21	AeroNotix	I moved from Blackpool to Poland to write Erlang+Clojure
09:21	Glenjamin	if you fancy heading over to Sheffield we're doing some ClojureScript at the functional programming meetup on tuesday
09:21	ingsoc	whatever you extra case you earn will be absorbed by property costs, unless you want shit loads of commuting wasting your life away
09:21	Glenjamin	http://defshef.github.io
09:21	AeroNotix	Sheffield/Leeds is where I am thinking of moving back to
09:21	Glenjamin	There's a lot more jobs in Leeds unfortunately :(
09:21	ingsoc	i meant, whatever extra you earn by working in London will be absorbed by property costs
09:22	AeroNotix	Glenjamin: that's what I've heard as well
09:22	Glenjamin	I think Sheffield is much nicer, but I'm biased
09:22	justin_smith	ingsoc: that's what folks say about SF around here
09:22	AeroNotix	my brother is in Leeds at the moment
09:22	Glenjamin	Where's he working?
09:22	AeroNotix	Just at Uni
09:23	the_frey	ingsoc you looking for a clojure job in manchester?
09:24	SagiCZ1	justin_smith: i mean... living in SF is exactly the same as anywhere else in the US.. except when you open the door outside.. you are in SF, haha
09:24	Glenjamin	the_frey: do some exist?
09:24	the_frey	our company is moving some infrastructure to it, I'm having to learn clojure for work atm :)
09:24	ingsoc	the_frey: no, I was just curious as to where the job market is heading, whether more opportunities are being created over time. I am a complete clojure noob, just started out today pretty much lol, I am an erlang and frontend web dev
09:25	the_frey	though tbf we are tiny
09:25	the_frey	right k
09:25	Glenjamin	oh neat, i could probably do some clojure in manchester
09:25	justin_smith	SagiCZ1: I meant in terms of the money you make / how much you pay for rent
09:25	the_frey	but yeah we are hiring (I think)
09:25	the_frey	lemme find the link
09:25	the_frey	http://www.swirrl.com/jobs
09:26	the_frey	our clojure yoda is the guy who runs lambda lounge in mcr, really really clever dude
09:26	SagiCZ1	justin_smith: you make more, you spend more.. you are living in Cali..
09:26	Glenjamin	is lambda lounge still going? i heard it had fizzled out
09:27	justin_smith	SagiCZ1: it seems like half of Cali is trying to move here
09:27	the_frey	Glenjamin: it became a lot more infrequent for a while because of the difficulty of finding speakers
09:27	the_frey	but it's got a bit more momentum of late
09:27	Glenjamin	oh cool, i should try and head across the pennines then
09:28	SagiCZ1	justin_smith: and half of the world is trying to move to Cali ...
09:28	the_frey	I _believe_ we might be sponsoring beers at the next one because I think we might be doing one of the talks
09:28	Glenjamin	might be able to blag some (def shef) speakers out of it
09:28	the_frey	about the graph data & RDF stuff we're doing in clojure
09:28	the_frey	hence why a rubyist like me is shifting over to it :)
09:29	justin_smith	I hear many stories of folks who get hired at a ruby shop and slowly push everything into clojure
09:29	ingsoc	the_frey: Rick ?
09:30	ingsoc	I did an erlang talk there a while back
09:30	AeroNotix	ingsoc: what're jobs like in the UK for Erlang?
09:30	ingsoc	was my first tech talk so was not as smooth as i wanted
09:30	ingsoc	:)
09:30	AeroNotix	I'm writing Erlang as a dayjob at the moment
09:30	the_frey	ingsoc yeah Rick, really nice guy to work with, gotta say
09:31	ingsoc	AeroNotix: mainly London based work, but there are some companies using it outside of London but it seems to be not widely publicised
09:31	AeroNotix	hmm, ok
09:33	Glenjamin	Someone's doing an Erlang POC at the mo in the company in Leeds I'm working for
09:33	ingsoc	AeroNotix: keyword search on a local jobsite brings back 18 with clojure and 12 with erlang, there are obviously thousands of java and .net and 100's of python/ruby
09:33	Glenjamin	but I suspect hiring concerns will mean it never makes it to production
09:34	AeroNotix	ingsoc: interesting. I write Erlang and Clojure at work but I am based in Poland (blackpool originally). Thinking of coming home soon.
09:34	Glenjamin	we're having enough issues hiring people who are any good at Node.js
09:34	AeroNotix	Glenjamin: then stop using node.js
09:34	AeroNotix	Solved.
09:34	AeroNotix	That'll be my daily fee, thanks
09:34	Glenjamin	hah
09:34	the_frey	Glenjamin to be fair we have trouble hiring rubyists :) there are crap programmers in every lang
09:34	ingsoc	AeroNotix: well I think these technologies are still kinda a technical edge over the competition that use traditional languages
09:35	Glenjamin	it's not so bad really, being JS you can write it functionally
09:35	ingsoc	so maybe their use doesn't get shouted about outside of their respective tech communities
09:35	Glenjamin	supervisord + rabbitMQ + node.js processes = poor man's erlang
09:35	AeroNotix	At that point just use Erlang
09:36	Glenjamin	well yes, but that doesn't really help us deal with the the 3 years-worth of code that's running and works
09:36	annelies	Write a JavaScript-to-BEAM compiler.
09:36	ingsoc	yeah in clojure
09:36	Glenjamin	which is why someone is doing an erlang proof-of-concept
09:37	ingsoc	someone created a javascript project that can interpret beam files in browser
09:37	annelies	Speaking of writing compilers in Clojure, core.logic seems a good fit for implementing type inference.
09:38	ingsoc	AeroNotix: Funny you say you moved from UK to Poland, usually it is the other way around
09:38	AeroNotix	ingsoc: tell me about it
09:38	ingsoc	did you meet a Polish girl in UK then emigrate with her
09:38	AeroNotix	duh
09:38	AeroNotix	:)
09:39	ingsoc	lol
09:39	ingsoc	what's wrong with meeting a nice English girl on a hen do in Blackpool
09:39	ingsoc	:P
09:39	ingsoc	lol
09:40	AeroNotix	yeah and be disgusted 24/7
09:40	ingsoc	tray of fish and chips and a couple of bacardi breezers for her
09:41	ingsoc	and you're in
09:41	AeroNotix	too easy, in my youth I took advantage of this :)
09:42	ingsoc	AeroNotix: what's the salary to living cost ration like in Poland ?
09:42	ingsoc	hoping it is better than what it appears to be for unskilled Polish workers
09:42	ingsoc	(which causes them to move here)
09:43	AeroNotix	ingsoc: I'm in a unique field so it's pretty good for me
09:43	AeroNotix	but for regular folk, it's hard. Of course.
09:43	AeroNotix	but I make 4kGBP a month so I'm not complaining.
09:43	AeroNotix	over here that's extremely good
09:44	ingsoc	how much is a tyskie over there ?
09:44	ingsoc	:)
09:44	AeroNotix	I don't drink piss
09:44	ingsoc	loool
09:44	ingsoc	well i don;t drink it, but I don;t know any other Polish beers
09:44	AeroNotix	Keep an eye out for Pinta or Ale Browar
09:45	ingsoc	i guess you would have to earn a fair bit more than that to live a similar standard in UK
09:46	AeroNotix	What are you getting?
09:46	ingsoc	sounds like you are doing pretty good then
09:48	ingsoc	I am currently taking time out to learn other things (living off investments) but when I was working it would be circa 55-60k per annum although this was not programming, I was working as operations management type role
09:48	ingsoc	I just have an interest in programming
09:48	AeroNotix	ok
09:49	AeroNotix	What're people using to generate documentation/
09:49	AeroNotix	?
09:50	ingsoc	AeroNotix: are you using clojure and erlang on the same system, or are these separate projects
09:51	ingsoc	just interested to how they are being used together
09:52	SagiCZ1	ingsoc: is it rude to ask people how much they make in UK?
09:52	AimHere	It can be, yes
09:52	ingsoc	erm, possibly yeah, but obviously it depends on individual. IRC is anonymous though
09:53	AeroNotix	ingsoc: Erlang is used for maintaining a high number of connections to hardware devices
09:53	AeroNotix	ingsoc: CLojure is used because Erlang isn't a general purpose language
09:53	ingsoc	I wouldn't walk up to someone in person and say oh btw what do you earn
09:53	AeroNotix	AimHere: yes it's rude but we are anonymous
09:54	SagiCZ1	ingsoc: i see, thanks
09:54	AimHere	Well he asked about the UK; on the Internet, the concept of 'rudeness' has long gone out of fashion
09:54	ingsoc	AeroNotix: so are you communicating with clojure over ports or some other mechanism
09:54	ingsoc	(erlang ports)
09:54	AeroNotix	ingsoc: typically HTTP
09:54	ingsoc	ok
09:54	AeroNotix	ingsoc: you could call it a microservices architecture
09:54	AeroNotix	Erlang forms the hub
09:54	AimHere	On the internet, you're a sophisticated gentleman, if you don't call people by racial or offensive epithets, or post pictures of people being beheaded more than once a day or so
09:55	ingsoc	I have used python (for certain libs not available in erlang) and communicated over port (stdio)
09:55	SagiCZ1	off topic, i am using joda time, and i have a date [year month day], and i need to know which week in the month is the day in.. first, second, third or fourth week.. how can i do that?
09:55	AeroNotix	ingsoc: I'd prefer HTTP over ports as a first pass, optimize as necessary
09:56	ingsoc	AeroNotix: i found it useful as you get to have the processes supervised by erlang so you only have to worry about keeping the erlang node running (which is generally bullet proof)
09:56	SagiCZ1	wait.. i could just do (quot 30 day) i guess
09:57	ingsoc	it wasn;t about optimisations
09:57	AeroNotix	ingsoc: meh, just use a proper init system which keeps processes alive
09:57	ingsoc	(OS Process running python/JVM)
09:57	ingsoc	yeah i notice ubuntu has upstart that can do that
09:58	ingsoc	restart mnechanism etc.
09:58	AeroNotix	indeed
09:58	ingsoc	(I am a windows guy originally but switched to linux as the open source ecosystem is much better)
09:59	annelies	SagiCZ1: just (quot day 7)
09:59	annelies	,(map #(quot % 7) (range 31))
09:59	clojurebot	(0 0 0 0 0 ...)
09:59	annelies	lol
10:00	ingsoc	does the "?" in odd? empty? have any special relevance other than it makes it visually appear as a question
10:00	AimHere	No. That's it's sole purpose
10:00	AeroNotix	ingsoc: just makes it a question
10:00	AimHere	There are no side effects
10:00	AeroNotix	some lisps use the -p suffix
10:01	AeroNotix	integerp stringp etc
10:01	AeroNotix	for predicate
10:01	SagiCZ1	zerop?
10:01	AeroNotix	SagiCZ1: just zero? or zerop
10:01	justin_smith	,(defn !? [a] (+ a a))
10:01	clojurebot	#'sandbox/!?
10:02	justin_smith	,(!? 2)
10:02	clojurebot	4
10:02	justin_smith	ingsoc: clojure has very few operators / special symbols. It's usually just part of a name.
10:04	justin_smith	in fact, the only things other than white space that I can think of that are contiguous with a name, but not part of it, would be () {} # . ^ [] (I may have missed one or two)
10:04	justin_smith	/ of course has special meaning inside a symbol too
10:05	justin_smith	@
10:06	justin_smith	` and '
10:07	annelies	You can have foo'bar as name.
10:07	justin_smith	ahh, and foo@bar too
10:07	justin_smith	,(def foo@bar 0)
10:07	clojurebot	#<CompilerException java.lang.RuntimeException: Too many arguments to def, compiling:(NO_SOURCE_PATH:0:0)>
10:08	justin_smith	or not
10:08	justin_smith	heh
10:08	annelies	you can with #
10:08	justin_smith	yeah, many of those are only special as the first character
10:08	justin_smith	none special as last
10:08	SagiCZ1	clj-time uses system language for the formatter, how can i switch it to english?
10:08	annelies	Here is the exact syntax: http://clojure.org/reader
10:08	SagiCZ1	this should give me the name of the month, but its in my local language:
10:08	SagiCZ1	(f/unparse (f/formatter "MMMMM") (t/date-time 2010 6))
10:08	annelies	Under "Symbols"
10:09	justin_smith	annelies: thanks
10:10	justin_smith	annelies: that's not really accurate, though, because it doesn't indicate that ' can be used (which is commonly used in symbols in practice)
10:11	annelies	SagiCZ1: eww assumptions. Anyway: (with-locale (f/formatter "MMMMM") java.util.Locale/ENGLISH)
10:11	annelies	Or Locale/ENGLAND maybe.
10:12	SagiCZ1	annelies: where is with-locale from? is it clojure.core?
10:12	annelies	in clj-time.format
10:13	SagiCZ1	annelies: thank you so much, works well
10:13	SagiCZ1	(inc annelies)
10:13	lazybot	⇒ 1
10:14	annelies	I wish tools did away with assuming default locales and time zones and stuff like that.
10:14	annelies	s/tools/libraries/
10:14	annelies	Such defaults are only useful in a very small set of programs.
10:15	SagiCZ1	very true
10:16	ingsoc	Ithought clojure was single-assignment so why does the repl allow reassignment ? just for convenience ? or is there something different at work ?
10:16	justin_smith	ingsoc: not single assignment at all
10:16	justin_smith	vars are mutable
10:16	ingsoc	ok it is within a defined namespace it is single assignment
10:16	justin_smith	no, vars are mutable
10:17	justin_smith	the value in the var is usually immutible, a var itself is not
10:17	justin_smith	and every var used in practice is in a namespace (def / defn can only make namespaced global definitions)
10:18	Glenjamin	SagiCZ1: i think you can set the default JVM locale to english, and most libs will use that as their default
10:19	Glenjamin	i've got :jvm-opts ["-Duser.language=en" "-Duser.country=GB"] in my project.clj, which i think is related
10:19	m1dnight	how are macros expanded, from the outside in, or the inside out?
10:19	SagiCZ1	Glenjamin: thanks
10:19	justin_smith	m1dnight: outside in - a macro decides how to handle each of its arguments
10:19	Glenjamin	,(macroexpand-1 '(and (and 1 2) 3))
10:19	clojurebot	(clojure.core/let [and__4069__auto__ (and 1 2)] (if and__4069__auto__ (clojure.core/and 3) and__4069__auto__))
10:20	m1dnight	aha excellent :) thank you
10:20	Glenjamin	forgot about symbol expansion, that's not as clear as i was expecting it to be
10:20	justin_smith	m1dnight: otherwise things like when / and etc. couldn't short circuit
10:20	m1dnight	ah, valid point
10:20	m1dnight	hadn't thought about ti that way
10:21	Wild_Cat	hold on, why is and a macro?
10:22	justin_smith	~source and
10:22	justin_smith	it uses if
10:22	justin_smith	if is the more fundamental
10:22	Wild_Cat	oh, because it does shortcut evaluation
10:23	justin_smith	as does or
10:23	Wild_Cat	right, makes sense.
10:23	gfredericks	if or and when, let not but-last.
10:23	Wild_Cat	I actually wouldn't have expected Clojure's boolean operators to do shortcut eval.
10:23	annelies	Why not?
10:23	gfredericks	new game - make english sentences out of clojure functions.
10:24	justin_smith	hah
10:24	gfredericks	"vector is not list."
10:26	annelies	,is
10:26	clojurebot	#<CompilerException java.lang.RuntimeException: Unable to resolve symbol: is in this context, compiling:(NO_SOURCE_PATH:0:0)>
10:26	justin_smith	,(require 'clojure.test)
10:27	clojurebot	nil
10:27	justin_smith	,#'clojure.test/is
10:27	clojurebot	#'clojure.test/is
10:27	justin_smith	it's a macro though
10:28	justin_smith	,(doc future-cancel)
10:28	clojurebot	"([f]); Cancels the future, if possible."
10:28	justin_smith	my favorite bit of poetry in the clojure codebase
10:28	Glenjamin	when short reductions compare and repeatedly cycle, double key locking
10:28	annelies	Sometimes I wish I were a prn-str.
10:28	Glenjamin	there's not many nouns :(
10:29	m1dnight	not any?
10:29	m1dnight	:D
10:29	justin_smith	the hard part is the lack of articles
10:29	Glenjamin	"do reductions keep rational?"
10:30	justin_smith	haha
10:30	justin_smith	agent prefers locking intersection
10:31	justin_smith	that would be better if I could use "the"
10:31	Glenjamin	"do some parents compare distinct?"
10:32	justin_smith	aha
10:32	annelies	do not take hash
10:32	justin_smith	parernts reverse, locking intersection
10:32	justin_smith	much better
10:34	annelies	Hmm, speaking of rearranging words, I should port my Markov chain library to Clojure.
10:34	justin_smith	I did one - I was amazed how succinct I could do everything in clojure actually
10:35	justin_smith	complete with optional seed and variable memory
10:35	annelies	Here is the existing one in Scala: http://ideone.com/Do2DTU
10:36	m1dnight	oh dear, second time this week i misspell "filter" with "fitler"
10:36	annelies	(def fitler filter) and nobody will notice :)
10:36	justin_smith	annelies: ah, yourse is by word, I did mine by character - which means with a shorter memory it is prone to inventing "words"
10:36	m1dnight	:D
10:37	annelies	Oh I meant just porting MarkovChain, not NonsenseGenerator
10:37	justin_smith	annelies: oh, that will be like a four liner I bet
10:38	annelies	Yeah. :P
10:38	annelies	Well, a protocol and a function transition
10:39	annelies	Mine is bugged actually. It fails if the PRNG returns exactly 0.0.
10:39	annelies	Then it throws a NotImplementedException :v
10:42	justin_smith	annelies: I am not very good at reading scala - does yours use start / stop tokens?
10:42	annelies	No idea what those are. :P
10:42	annelies	The nonsense generator just constructs a map of (current word, set of possible next words) pairs
10:43	annelies	And then it starts at a random word.
10:43	justin_smith	annelies: when analyzing an input, a start token is inserted at the beginning, a stop token appended at the end, then "generate" will start with one of the start tokens (with a weighed probability) and stop if it reaches a stop token.
10:44	ingsoc	AeroNotix :name <- is this kinda like an atom in erlang
10:44	annelies	Oh no it just picks a random word to start with. There is no stop token, it stops when you stop calling transition.
10:45	annelies	So to construct a nonsense paragraph just reduce with transition and string concatenation
10:45	AeroNotix	ingsoc: yeah
10:45	AeroNotix	ingsoc: but there's no atom table
10:45	oskarkv	Say I want to use JavaFX or Swing or some other Java lib. And I have an idea for a new Node/Control (like Label, Image, Button). Then I would like to create a named class, that can extend a class and implement interfaces. What would you guys use for that? It almost seems like the easiest choice would be to forget about the named class thing and make a proxy for each instance.
10:45	justin_smith	annelies: an interesting side effect of using start/stop tokens is that if your input was grammatical, the output will start with a capitalized word, and end with a period / newline
10:45	AeroNotix	ingsoc: so you can make as many as you want
10:45	annelies	justin_smith: a right :p
10:46	justin_smith	oskarkv: yeah, proxy or refiy likely
10:46	justin_smith	*reify
10:46	justin_smith	time for coffee
10:46	grandy	anyone know the best practice for server side session state in compojure ?
10:46	oskarkv	but reiddraper can't extend classes, right?
10:46	oskarkv	ops
10:47	oskarkv	reify*
10:47	justin_smith	I am pretty sure reiddraper has extended quite a few classes :)
10:47	oskarkv	hehe
10:47	oskarkv	Wouldn't it make sense for clojure to be able to make new named classes for interop purposes?
10:47	justin_smith	oskarkv: reify can implement any number of interfaces
10:48	grandy	is it ring-clojure ?
10:48	oskarkv	or maybe that's what genclass does
10:48	oskarkv	justin_smith yeah but not extend classes right?
10:48	justin_smith	oskarkv: right, but swing should only care about interfaces, not classes for the most part, I would hope
10:48	justin_smith	oskarkv: maybe my optimism is misplaced
10:48	oskarkv	hehe
10:49	oskarkv	Sometimes it saves work to extend :p
10:49	justin_smith	anyway, if interfaces are sufficient (hopefully they are), with the help of defprotocol you can extend however you like - unless it actually needs you to inherit specific classes
10:50	annelies	Weighted choice is one of those things I love implementing imperatively rather than functionally.
10:50	justin_smith	heh
10:50	ingsoc	AeroNotix: ok thanks
10:50	AeroNotix	ingsoc: nw
10:51	justin_smith	annelies: my rng is of course imperative, but I actually did the weighted choice as a pure function otherwise
10:51	annelies	You can write pure functions using imperative programming.
10:51	justin_smith	of course
10:51	justin_smith	but I used standard fn / reduce and no state mutation is what I mean
10:53	grandy	ok fine
10:54	justin_smith	grandy: ring-clojure is a session state?
10:54	grandy	it has a session namespace
10:54	justin_smith	yeah - compojure is just a routing lib
10:54	justin_smith	for the other stuff, you want to look at ring middlewares
10:55	grandy	justin_smith: cool that's what i thought but wanted to make sure i hadn't missed something... there have been a few deprecated projects in this area
10:55	justin_smith	it's true
10:56	justin_smith	grandy: I've never even heard of someone using compojure without ring
10:56	justin_smith	though it may be hypothetically possible
10:56	grandy	justin_smith: cool yeah i think there have been some other libs that may do some session stuff too, also on top of ring
10:57	justin_smith	right, and they will all act as a ring middleware
10:57	annelies	Hmm, I guess I can use reductions for it.
10:57	SagiCZ1	,(for [i "abc"] (for [j (range 3)] (str i j)))
10:57	SagiCZ1	i need this to return ("a0" "a1" "a2" "b0"... should i use flatten?
10:57	clojurebot	(("a0" "a1" "a2") ("b0" "b1" "b2") ("c0" "c1" "c2"))
10:58	justin_smith	grandy: I use ring.middleware.session/wrap-session
10:58	grandy	justin_smith: ahh ok perfect that looks useful
10:58	justin_smith	grandy: you can specify what sort of storage you want with that
10:59	grandy	justin_smith: cool
10:59	SagiCZ1	nevermind, got it
11:00	justin_smith	SagiCZ1: you don't need to ever nest for calls
11:00	justin_smith	,(for [i "abc" j (range 3)] (str i j))
11:00	clojurebot	("a0" "a1" "a2" "b0" "b1" ...)
11:01	SagiCZ1	yeah i found that out, thanks
11:01	justin_smith	OK - just making sure you figured out the simple way
11:05	annelies	I think I got it: https://gist.github.com/rightfold/a2394f6d9cd785fcc990
11:05	justin_smith	very nice
11:05	justin_smith	better than mine
11:05	justin_smith	https://github.com/noisesmith/markov-toy/blob/master/src/markov/core.clj#L14
11:08	oskarkv	,(for [i "abc" j (range 3)] (str i j))
11:09	clojurebot	("a0" "a1" "a2" "b0" "b1" ...)
11:09	oskarkv	oh, was scrolled up :p
11:17	m1dnight	guys, I'm having a brainy problem. At runtime I want to add stuff to a list and then return that list.
11:17	m1dnight	The reason is that I need the values of the expression before.
11:17	m1dnight	Is there an idiomatic way?
11:18	m1dnight	since immutability and all ..
11:18	m1dnight	wait a minute
11:19	m1dnight	yeah, still. I have a function that does a message send to a thread. But this send could contain values that are in the current lexical scope. However, I want to do those message sends during a commit. Ergo, I have to get the values out of scope to use them in a differnet one
11:20	m1dnight	So I figured I could 'cons' them to a list (to say it in lisp terms) and then return that list to the other scope
11:20	Glenjamin	m1dnight: can you provide a code sample i'm not clear why (cons) isn't enough here?
11:21	m1dnight	well, I have a meta-circular STM implementation. I also have an implementation of Erlang actors. Now in my state change of my actors (ie the body) I want to send messages to other actors.
11:21	m1dnight	But, i'm experimenting with an actor that has a dosync in his body, and inside that dosync, sends a message to another actor
11:22	m1dnight	I want to hold that message back until commit.
11:22	m1dnight	but, since the commit happens in a different scope, i need to get the values that are sent to an actor in a message out of the scope
11:24	Glenjamin	you might be able to do something with http://clojure.github.io/clojure/clojure.core-api.html#clojure.core/add-watch
11:24	m1dnight	wait a minute, i think you gave me an idea :D
11:24	m1dnight	!è
11:24	Glenjamin	if i'm understanding, you want to queue up message sends until your current actor transaction is finished, then send them
11:24	m1dnight	yes, indeed
11:25	m1dnight	but that's easy, because a message is a keyword (e.g., :message)
11:25	m1dnight	so I can do something like (! actor :message <var> <var>..)
11:25	m1dnight	that sends the message :message to the actor and attaches the values <var>
11:30	cristian	Hi guys. I wonder what's the idiomatic way in clojure to define functions that might fail or that might return null. In Java 8, I'm mostly using Optional. In Haskell I use Maybe and Either.
11:31	cristian	How do you usually implement such functions in Clojure?
11:31	Glenjamin	generally i'd just return null
11:31	ingsoc	AeroNotix: lein repl :connect seems like a it provides some of the remsh stuff of erlang
11:31	Glenjamin	i think core.typed has a way of saying whether a function will or wont return null
11:31	ingsoc	have you sued this ?
11:31	ingsoc	used*
11:31	AeroNotix	ingsoc: it does
11:32	Glenjamin	a lot of core functions do something useful if you pass null
11:32	Glenjamin	,(assoc nil :a 1)
11:32	clojurebot	{:a 1}
11:33	ingsoc	AeroNotix: can you reload new version of code ?
11:33	ambrosebs	cristian: do you want to know how to define such functions or use their outputs?
11:33	AeroNotix	ingsoc: yes, much better than the way Erlang does it, too.
11:33	AeroNotix	ingsoc: because you don't have supervision trees to tear down as a whole, you can just redefine whatever you need in-place and the running code picks it up.
11:34	Glenjamin	AeroNotix: as long as there's no state :D
11:34	justin_smith	ingsoc: as I mentioned before, vars are mutable, so to the extent that your code is all vars, yes - the tricky thing is of course any closed over state, sometimes to get a good reload you need to define a restart of some sort
11:34	Glenjamin	see also, the "component" library
11:34	AeroNotix	Yeah component is really good
11:34	justin_smith	Glenjamin: yes, component was what I was getting at :)
11:34	ingsoc	hmmm, to get this straight in my mind, does the Java VM when running clojure listen on the nrepl port all the time
11:35	ingsoc	so you can connect at any time or do you have to enable something in the project ?
11:35	Glenjamin	ingsoc: when you run "lein repl", it starts a client+server
11:35	justin_smith	ingsoc: only if you open an nrepl listener
11:35	justin_smith	lein opens one for you
11:35	justin_smith	or you can do so yourself in production code if you wish
11:35	justin_smith	but you should not use lein in production
11:35	AeroNotix	In production code I have nrepl spawning a listener as part of main
11:36	ingsoc	ok i see. I was doing this in counterclockwise. I spose when you run your project in counterclockwise it does plumbing for you
11:36	annelies	I wish I wrote production code.
11:36	AeroNotix	annelies: Why don't you?
11:36	ingsoc	(it runs lein)
11:37	justin_smith	ingsoc: the code to start your own nrepl server is clojure.tools.nrepl package
11:37	justin_smith	it's pretty easy
11:38	cristian	ambrosebs: I want to know how you define such functions. For instance, you can define a function that returns Either in Scala (or haskell), and the client of the function knows that it has to pattern match the result to know if the computation succeeded or not (and if not, you get useful data about what went wrong). How do you guys handle such cases in clojure? I don't want to just emulate what I do in
11:38	cristian	imperative languages... I want something more Clojure-idiomatic
11:38	annelies	AeroNotix: I mean in Clojure.
11:39	annelies	I write it in Python though.
11:39	ambrosebs	cristian: in Clojure you just return null in the function and document it in the docstring or contract.
11:39	cristian	Ok
11:39	cristian	Thanks
11:40	Glenjamin	ambrosebs: does core.typed let you annotate as "will not return null" ?
11:40	ambrosebs	Glenjamin: yes, references are non-nullable
11:40	annelies	cristian: it's better to use \/ than Either for that in Scala. Either isn't designed for failure vs. success, but just as a utility union type.
11:40	Glenjamin	and presumably with anything that can return null i have to handle it to type check?
11:40	ambrosebs	cristian: check out some->, when for some macros to help use nullable values
11:41	cristian	annelies: pardon my ignorance... what do you mean by \/
11:41	ingsoc	i need to learn how this works then. I thought this wasn't possible on JVM and afaict all clojure code is compiled into java classes / byte code ? so what's the deal there ? Or could you also do this with java code ?
11:41	ambrosebs	Glenjamin: yes, just in the same way you'd do it in clojure. (fn [a :- (U nil Int)] (when a (inc a)))
11:42	Glenjamin	i think mostly i forget to check for nil :) i should really find an excuse to play with core.typed
11:42	justin_smith	ingsoc: it's the opposite - every object in the jvm is nullable, and we just adapt to that
11:42	annelies	cristian: http://docs.typelevel.org/api/scalaz/nightly/#scalaz.$bslash$div has a right-bias (right indicates success) for map, filter etc... which is far more useful than Either's left and right projections when dealing with failure vs. success
11:44	ingsoc	just looking at jetty, looksamazingly easy to providew a simple http api
11:44	justin_smith	ingsoc: in clojure, use ring
11:44	ingsoc	fun stuff :)
11:44	ingsoc	ring ?
11:44	ingsoc	oh ok
11:44	justin_smith	there are very few reasons not to use the ring abstraction
11:45	cristian	annelies: thanks. That's interesting. Why doesn't clojure have something like that? Is it not need ti?
11:45	ambrosebs	Glenjamin: a good excuse, but my advice is to become comfortable with some-> and the like.
11:45	justin_smith	it turns mutating code on streams into pure functions of request-map / response-map
11:45	annelies	cristian: No idea. I always throw exceptions when something goes wrong.
11:46	ambrosebs	Glenjamin: or least use contracts to be explicit about what values you think are allowed at certain points.
11:46	justin_smith	correct me if I am wrong, but my gist is that as opposed to the scala approach where they try to define a more sane semantics (and all the work that goes into that...) clojure takes the lazier approach of taking the java semantics as a given and dealing with it in a way that tries to minimize complexity
11:46	Glenjamin	ambrosebs: i suspect the greater benefit to me would be the tool reminding me i forgot to use some/when/if/or etc
11:46	ambrosebs	Glenjamin: sure, core.typed is the perfect tool for that.
11:46	ambrosebs	it will find all the cases you forget in typed code.
11:48	ambrosebs	the only time I've described core.typed as the perfect tool for anything.
11:49	Glenjamin	haha
11:49	ambrosebs	but you exactly described the reasons for core.typed's existence
11:49	justin_smith	ambrosebs: your humility is appreciated
11:49	ambrosebs	:)
11:54	ingsoc	AeroNotix: last question for the day (hopefully :P). Overall what are your impressions of clojure as a compliment to erlang and how it compares on productivity to alternatives ?
11:57	annelies	Heh, clojure as a compliment to erlang. "Hey erlang, you've got a nice clojure there!"
11:57	ingsoc	:)
11:57	ingsoc	:P
11:57	justin_smith	"hey erlang, love those actors, mind if I borrow a few ideas?"
11:58	annelies	such as lightweight processes ;_;
11:58	justin_smith	annelies: isn't this what core.async was going for?
11:59	annelies	Never looked into core.async.
11:59	ingsoc	well erlang = (robustness, concurrency, stability) clojure = (speed, libraries, deployability, lisps - so worth learning to expand programming knowledge)
11:59	ingsoc	this is how i am viewing it
12:00	annelies	Elixir runs on the Erlang VM and borrows many ideas from Clojure.
12:00	pdk	it's got...
12:00	pdk	a promising future
12:00	annelies	Such as macros and protocols.
12:00	justin_smith	ingsoc: clojure is no slouch on concurrency eitehr, if you compare it to anything but erlang :)
12:00	annelies	If you are into that stuff.
12:03	andyf	ambrosebs: core.typed is also the perfect tool to break Eastwood, and/or stretch it to its limits :)
12:03	ambrosebs	andyf: glad to be of service
12:03	andyf	I think I?ll declare it done when it gives correct warnings for core.typed :)
12:04	ambrosebs	hehe
12:04	andyf	That reminds me, there is a pretty darn big function generated via macro in one namespace I wanted to note to you. Let me find its name.
12:05	justin_smith	andyf: I've wondered, is eastwood named after the actor?
12:05	andyf	justin_smith: Clojure LINT :)
12:05	justin_smith	omg it's worse than I imagined
12:05	justin_smith	thanks
12:06	andyf	Jonas Enlund came up with the name, so I can't take credit. I wish I would have thought of it.
12:07	Glenjamin	thats genius
12:09	andyf	ambrosebs: Also, I have to ask, what do you use to navigate your 150+ namespaces? :)
12:09	ambrosebs	andyf: is it that many?! vim's Command-T
12:10	andyf	Counting test namespaces, definitely. I don't recall if non-test namespaces exceed that on their own.
12:12	ambrosebs	well that's a great success. I had a few 8000 liners a few years ago.
12:14	andyf	ambrosebs: Namespace clojure.core.typed.base-env-clj-rclass, the delay-and-cache-env call. It is only too large for Eastwood, not Clojure, I think because of extra tools.reader metadata and the way syntaxquote works. That means it is probably within a factor of 2 of being too large for Clojure, though.
12:15	ambrosebs	andyf: oh that's a stupid hack. I can fix that for you.
12:15	ambrosebs	andyf: it should really be reading those forms from a separate file, the code should be minimal.
12:16	andyf	No need to fix it for me, but I certainly won't stop you if you wish ;)
12:16	ambrosebs	sure
12:17	andyf	You aren't the first to auto-generate huge Clojure functions, and you won't be the last. 64KB max method size seems strangely small for the JVM bytecode, but I understand there has to be a limit somewhere.
12:17	annelies	After being here for a few hours I can say I like this chatroom.
12:18	ambrosebs	the other delay-and-cache-env calls hit the method limit all the time.
12:22	andyf	core.typed: 161 non-test namespaces, 143 test namespaces. 304 total. Not counting cljs
12:22	ambrosebs	wow!
12:23	justin_smith	I have libraries with fewer lines than that
12:24	Glenjamin	does that include all the clojure.core annotations?
12:24	ambrosebs	Glenjamin: that's just one file
12:26	andyf	Glenjamin: If you were asking me regarding core.typed namespaces, I don't know which ones contain those annotations.
12:26	ambrosebs	https://github.com/clojure/core.typed/blob/master/module-check/src/main/clojure/clojure/core/typed/base_env.clj
12:26	ambrosebs	it's a big un
12:27	Glenjamin	i love how a "big" clojure file is < 2k lines
12:27	Glenjamin	i've had similar "this is getting a bit big" feelings, then looked to note the file is ~250 lines
12:27	justin_smith	Glenjamin: yeah, seriously
12:28	justin_smith	Glenjamin: I propose that the platonic ideal of a clojure namespace is a perfect square: longest line is 80 chars, 80 lines long.
12:29	Glenjamin	otoh, a huge flat namespace of non-interacting pure functions is probably still quite tidy
12:29	justin_smith	of course
12:29	Glenjamin	did you see the joe armstrong post about namespaces recently?
12:30	ambrosebs	if anyone needs a big ns form for some reason: https://github.com/clojure/core.typed/blob/master/module-check/src/main/clojure/clojure/core/typed/check.clj
12:30	Glenjamin	http://erlang.org/pipermail/erlang-questions/2011-May/058768.html
12:30	Glenjamin	read that this week - only just noticed it's > 3 years old
12:30	justin_smith	Glenjamin: the one where he digressed to talk about letrec, yeah
12:31	justin_smith	I think technomancy brought it up recently
12:31	Glenjamin	aha
12:32	Glenjamin	i have occasionally thought to build to "lein util" plugin, that lets you build your util.clj namespace by pulling functions from a remote repo w/ metadata into one file
12:33	andyf	Glenjamin: To avoid the extra dependency for utils only?
12:34	Glenjamin	andyf: yeah, and flatten it a bit
12:34	Glenjamin	core.experimental, useful, medley etc could all just be functions in a util-function repository
12:35	andyf	I've got a pre-alpha 'dolly' lib that helps me copy code into Eastwood source and rename its namespaces, to avoid namespace version conflicts with projects being linted.
12:35	Glenjamin	similar sort of idea i guess, but for fns
12:35	andyf	I wouldn't recommend it for general use: https://github.com/jafingerhut/dolly
12:35	Glenjamin	that sounds like it'd be very useful for lein itself too
12:36	andyf	Glenjamin: Are there often conflicts between Leiningen namespaces and namespaces of projects managed by Leiningen?
12:36	Glenjamin	i've had issues between lein and speclj before
12:37	Glenjamin	only affects plugins, not app code
12:37	Glenjamin	unless the app pulls in lein for some reason
12:41	andyf	Yes, my guess was that something like dolly would be useful for some plugins, but not a lot else.
12:49	m1dnight	Hmm, I get "can not embed object in code" when I try to build a macro
12:49	m1dnight	I want to grab a variable defined in the scope of macro expansion, is that not possible? (a macro to be specific)
12:50	m1dnight	I.e., create a variable in your macro function, and make the expanded code use it
12:50	m1dnight	I'll build a minimal testcase, to make things clear perhaps
12:50	AeroNotix	show the code
12:51	m1dnight	okay, but it might be confusing :p
12:51	m1dnight	hold on
12:52	AeroNotix	because it sounds like you just want a gensym
12:52	AeroNotix	unless you're making an anaphoric macro, of which I am not going to help anyone make one of those.
12:52	justin_smith	AeroNotix: how principled of you
12:53	AeroNotix	justin_smith: I find anaphoric macros incredibly annoying
12:53	justin_smith	AeroNotix: does #(= x %) count?
12:54	AeroNotix	justin_smith: no
12:54	AeroNotix	justin_smith: you provide the symbol, technically
12:55	m1dnight	https://www.refheap.com/92918
12:55	justin_smith	oh, so as-> would be anaphoric
12:55	m1dnight	what is an anaphoric macro? :p
12:55	justin_smith	http://en.wikipedia.org/wiki/Anaphoric_macro
12:56	m1dnight	I have a list of expressions, but I want to modify them, such that they instead of execute, put their parameters in an atom
12:56	m1dnight	afterwards, I'll execute another function that will do something with those parameters
12:56	ingsoc	Macros scare me. Well, I mean maintaining code that someone had gone macro crazy with would be scary
12:56	m1dnight	in a different lexical scope
12:56	hyPiRion	m1dnight: imagine if-let worked like this: (if-let (get my-map :foo) (+ 2 it) 1) – where it is the result of the if-let expression
12:57	AeroNotix	ingsoc: it's all about using them judiciously
12:57	justin_smith	ingsoc: to be fair, things like ->, ->>, or, and, when, def, defn are indespensible - but making new macros definitely demands a compelling reason
12:57	m1dnight	I'm just trying to make a proof of concept here, not production code :p
12:58	AeroNotix	m1dnight: what are you actually trying to accomplish
12:58	m1dnight	well, I have a list of expressions that I execute in a dosync block. One of those expressions can be "(! actor message [values])"
12:58	m1dnight	but, in a dosync block we can retry, so I have to make sure to send those messages only once.
12:59	arrdem	for those of you who hanve't tried it, I highly reccomend core.logic+pldb if you want to play with a smallish dataset
12:59	justin_smith	m1dnight: what about using a delay for that? a delay will only be realized once
12:59	m1dnight	euhm
12:59	m1dnight	holy beep beep beep
12:59	justin_smith	,(def d (delay (do (println "realized") 1)))
12:59	clojurebot	#'sandbox/d
12:59	justin_smith	,@d
12:59	clojurebot	realized\n1
13:00	justin_smith	,@d
13:00	clojurebot	1
13:00	m1dnight	that could work as well
13:00	m1dnight	but what I was trying to accomplish was
13:01	m1dnight	transform any expression in the dosync of form (send actor message [vars]) to (swap! storage (fn [msgs] (cons {:msg message :actor actor :vars vars} msgs))
13:01	m1dnight	this way, I can send the messages during commit phase
13:02	m1dnight	but since that commit phase happens in a different lexical scope I have to figure out something such that I can write to an atom or something outside the scope of my actual dosync body
13:02	m1dnight	which I can then access in the scope present during committing
13:02	m1dnight	hence, I tried putting my code in a let as yo ucan see
13:03	AeroNotix	m1dnight: your juxt function doesn't seem right
13:03	m1dnight	oh, it is
13:03	m1dnight	output is right, is what i mean by that :p
13:03	justin_smith	AeroNotix: what's wrong with that juxt?
13:04	AeroNotix	justin_smith: looks like they wanted to split the expressions into things which begin with #'! and those which don't
13:04	justin_smith	,((juxt filter remove) even? (range 10))
13:04	clojurebot	[(0 2 4 6 8) (1 3 5 7 9)]
13:04	justin_smith	and that's what it does
13:04	m1dnight	AeroNotix: yes so I can then transform those to the form I showed above
13:04	AeroNotix	Right yeah I expected that to remove them altogheter
13:05	justin_smith	m1dnight: I can't prove it, but this almost smells like a hand rolled monad
13:05	m1dnight	hahaha
13:06	m1dnight	spare me monads, please
13:06	m1dnight	:'(
13:06	arrdem	hahaha
13:06	arrdem	don't fear the state monad :P
13:06	m1dnight	I don't fear it, if I can keep it at a safe distance in a cage
13:06	m1dnight	\o/
13:07	justin_smith	your problem is that you are using ~ on delayed-msgs
13:07	justin_smith	that doesn't really make sense
13:07	m1dnight	yeah, when i remove it I get what I want, but then it says it cant find the variable
13:07	justin_smith	remember that your macro should build the form to compile, not run the code you want run directly
13:07	m1dnight	no such var: meta-clojure.stm.actor-friendly/delayed-msgs
13:08	justin_smith	m1dnight: right, because it is not bound in that scope - I think you want to return a binding form that captures the atom
13:08	m1dnight	oh
13:08	justin_smith	`(let [delayed-msgs# (atom {})] ...)
13:09	AeroNotix	>>> because it sounds like you just want a gensym
13:09	justin_smith	AeroNotix: right, some of us were a bit slower connecting the dots
13:09	AeroNotix	No, I just called it. I didn't look too hard at the code! :)
13:09	AeroNotix	justin_smith: good job on figuring it out :)
13:10	justin_smith	but the gensym isn't the crux of it, the need to capture the binding is - the gensym is just one tool in doing that
13:11	madscientist`	0
13:11	madscientist`	doh
13:11	m1dnight	yeah, I was too focused on capturing the atom and forgot about just putting it in the macro as well
13:11	m1dnight	thanks a bunch :) really
13:12	justin_smith	m1dnight: yeah a macro body can capture a literal form to be embedded, but cannot capture a value
13:12	m1dnight	my head is de-hurting at the moment :D
13:12	m1dnight	I get it \o/
13:12	justin_smith	awesome
13:19	m1dnight	what does wrong number of args (-1) mean, actually?
13:19	m1dnight	0+ would be more logical, no? :p
13:25	justin_smith	yes, that is weird
13:25	andyf	m1dnight: There is a bug in Clojure for wrong arity errors for macros that subtracts 2 because macros have &form &env hidden args.
13:25	justin_smith	m1dnight: but macros get two invisible arguments
13:25	andyf	I've seen a CLJ ticket for it.
13:25	andyf	I think
13:25	m1dnight	oh that might explain :D
13:25	justin_smith	yeah, that is about it
13:26	justin_smith	clojure, the land of leaky abstractions
13:30	andyf	http://dev.clojure.org/jira/browse/CLJ-1279 Vote early, vote often.
13:34	arrdem	justin_smith: eh could leak worse
13:34	justin_smith	arrdem: sure, but we do have a lot of them if you go looking
13:35	arrdem	I guess
13:38	justin_smith	arrdem: I never really got the impression that seamlessness in abstractions was even a goal with clojure. I mean we don't really make much effort to hide implementation details in general.
13:38	justin_smith	not a dig or a complaint, just an observation of the design style
13:39	bbloom_	i think that if an abstraction is well designed, you don't have to bother hiding the implementation details: people simply won't go looking for them
13:40	justin_smith	bbloom_: right, so we let them leak, they are useful regardless
13:40	bbloom_	,(.tail []) ; whoops!
13:40	clojurebot	#<Object[] [Ljava.lang.Object;@189f393>
13:41	AeroNotix	Yeah the JVM leaks through everywhere
13:41	bbloom_	,clojure.lang.PersistentVector/EMPTY_NODE
13:41	clojurebot	#<Node clojure.lang.PersistentVector$Node@537a5a>
13:41	bbloom_	,(.tail clojure.lang.PersistentVector/EMPTY_NODE)
13:41	clojurebot	#<IllegalArgumentException java.lang.IllegalArgumentException: No matching field found: tail for class clojure.lang.PersistentVector$Node>
13:42	bbloom_	,(.tail (clojure.lang.PersistentVector/EMPTY_NODE))
13:42	clojurebot	#<IllegalArgumentException java.lang.IllegalArgumentException: No matching field found: tail for class clojure.lang.PersistentVector$Node>
13:42	bbloom_	,(.array (clojure.lang.PersistentVector/EMPTY_NODE)) ; ah of course
13:42	clojurebot	#<Object[] [Ljava.lang.Object;@8ded54>
13:43	bbloom_	,(.shift [])
13:43	clojurebot	5
13:43	bbloom_	,(set! (.shift []) 0)
13:43	clojurebot	#<IllegalAccessException java.lang.IllegalAccessException: Can not set final int field clojure.lang.PersistentVector.shift to java.lang.Integer>
13:43	bbloom_	aw, final
13:44	bbloom_	oh well, still
13:44	AeroNotix	bbloom_: yes Clojure is on the JVM :)
13:44	bbloom_	AeroNotix: i was trying to break all vectors w/o reflection :-P
13:45	bbloom_	well, w/o nefarious reflection
13:46	andyf	bbloom_: You can break their immutability without much effort by aset'ing .tail
13:46	bbloom_	andyf: that i know / have done in this very channel before :-) i was trying to break ALL vectors
13:47	andyf	You mean, one Java interop call that would cause every instance of a vector to behave incorrectly from that point forward?
13:47	bbloom_	yes
13:47	justin_smith	bbloom_: we played with a similar trick for breaking the number 5
13:47	justin_smith	it was amusing
13:47	bbloom_	justin_smith: do share
13:48	justin_smith	finding it in my notes
13:48	gfredericks	(.tail [1 2 3])
13:48	gfredericks	,(.tail [1 2 3])
13:48	clojurebot	#<Object[] [Ljava.lang.Object;@1ba146b>
13:48	justin_smith	,(let [field (nth (.getDeclaredFields Long) 3)] (.setAccessible field true) (.set field 5 2))
13:48	clojurebot	nil
13:48	justin_smith	,(inc 5)
13:48	clojurebot	3
13:48	andyf	You can break the JVM's 5, but Plato's 5 is safe in the world of forms
13:49	justin_smith	haha
13:49	gfredericks	~5 is the set of all sets with 5 elements
13:49	clojurebot	Ik begrijp
13:49	bbloom_	, (.getDeclaredFields Long) 3)
13:49	clojurebot	#<Field[] [Ljava.lang.reflect.Field;@5753b0>
13:49	bbloom_	,(.getName (.getDeclaredFields Long) 3))
13:49	clojurebot	#<IllegalArgumentException java.lang.IllegalArgumentException: No matching method found: getName for class [Ljava.lang.reflect.Field;>
13:49	bbloom_	,(.name (.getDeclaredFields Long) 3))
13:49	clojurebot	#<IllegalArgumentException java.lang.IllegalArgumentException: No matching method found: name for class [Ljava.lang.reflect.Field;>
13:49	bbloom_	,(clojure.reflect/reflect (.getDeclaredFields Long) 3))
13:49	clojurebot	#<ClassNotFoundException java.lang.ClassNotFoundException: clojure.reflect>
13:49	bbloom_	,(require 'clojure.reflect)
13:49	clojurebot	nil
13:49	bbloom_	eh wahtever... how do i get the name of a field?
13:50	gfredericks	.getName?
13:50	bbloom_	i tried that
13:50	bbloom_	oh dur it's an array
13:50	gfredericks	with 3?
13:50	bbloom_	,(.name (nth (.getDeclaredFields Long) 3))
13:50	clojurebot	#<IllegalArgumentException java.lang.IllegalArgumentException: No matching field found: name for class java.lang.reflect.Field>
13:50	bbloom_	i suck
13:50	bbloom_	,(.getName (nth (.getDeclaredFields Long) 3))
13:50	clojurebot	"value"
13:51	andyf	The world of forms: Bringing you real immutability since 348 BC
13:51	bbloom_	ah ok i gotcha. boxed small numbers are interned
13:51	justin_smith	, (nth (.getDeclaredFields Long) 3)
13:51	clojurebot	#<Field private final long java.lang.Long.value>
13:51	justin_smith	,(.getName (nth (.getDeclaredFields Long) 3))
13:51	clojurebot	"value"
13:51	bbloom_	andyf: https://en.wikipedia.org/wiki/348_BC <- i was hoping you knew the actual year
13:51	justin_smith	bbloom_: ^
13:52	bbloom_	justin_smith: i got there eventually :-P
13:52	justin_smith	bbloom_: aha, I missed it while I was finding it in my own repl
13:52	andyf	Sorry, I don't know when he wrote about it first, so I approximated by the year Plato died.
13:53	justin_smith	,(= 5 3)
13:53	clojurebot	false
13:53	justin_smith	,(= 5 2)
13:53	clojurebot	true
13:54	justin_smith	,(let [field (nth (.getDeclaredFields Long) 3)] (.setAccessible field true) (.set field 5 (inc 4)))
13:54	clojurebot	nil
13:54	justin_smith	,(= 5 2)
13:54	clojurebot	true
13:54	justin_smith	I thought I fixed that...
13:54	justin_smith	,(let [field (nth (.getDeclaredFields Long) 3)] (.setAccessible field true) (.set field (inc 4) (inc 4)))
13:54	clojurebot	nil
13:54	justin_smith	,(= 5 2)
13:54	clojurebot	true
13:54	justin_smith	,(inc 2)
13:54	clojurebot	3
13:54	justin_smith	,(inc 5)
13:54	clojurebot	3
13:54	mearnsh	this is why we can't have nice things
13:55	AeroNotix	,(inc (+ 3 2))
13:55	clojurebot	6
13:55	justin_smith	:( I forgot how to fix it
13:55	AeroNotix	,(inc 5)
13:55	clojurebot	3
13:55	AeroNotix	5
13:55	AeroNotix	,5
13:55	clojurebot	2
13:55	justin_smith	,(let [five (long (int (+ (int 1) (int 4)))), field (nth (.getDeclaredFields Long) 3)] (.setAccessible field true) (.set field five (int (+ (int 1) (int 4)))))
13:55	clojurebot	nil
13:55	andyf	Once you make 5 equal to something else, the JVM extrapolates and is able to prove that all numbers are simultaneously equal to, and not equal to, all others.
13:55	justin_smith	,5
13:55	clojurebot	5
13:55	justin_smith	ok, found the fix
13:55	justin_smith	andyf: if only
13:55	andyf	It's downhill from there
13:56	bbloom_	this statement is false.
13:56	andyf	and simultaneously not downhill from there
13:56	justin_smith	I can't take credit for the trick, I just made a note of it to study, amalloy_ was who I saw do it
14:00	AeroNotix	,(inc [])
14:00	clojurebot	#<ClassCastException java.lang.ClassCastException: clojure.lang.PersistentVector cannot be cast to java.lang.Number>
14:08	m1dnight	What function do I have to map over a list of functions to execute all of them?
14:09	justin_smith	#(%)
14:09	justin_smith	equivalently (fn [f] (f))
14:09	m1dnight	riiight!
14:09	m1dnight	thanks justin_smith
14:09	justin_smith	np
14:10	justin_smith	if you want to get way into semantic overload, (fn [fn] (fn)) actually works
14:10	m1dnight	hahaha
14:10	arrdem	hehe
14:10	justin_smith	but that shadows fn which is weird so don't do that
14:11	m1dnight	:D
14:11	andyf	justin_smith: Please, no. Zach Tellman's Manifold library defines a function called 'catch' that uses try/catch in its definition.
14:11	justin_smith	,(take 42 (map (fn [fn] (fn)) (repeat (constantly 42))))
14:11	clojurebot	(42 42 42 42 42 ...)
14:11	justin_smith	andyf: ouch
14:12	andyf	It all works, where the catch occurrences inside try are try/catch, and the ones not inside try are the function, but yeah, weird.
14:13	justin_smith	yeah, that seems gratuitously clever
14:13	gfredericks	,((fn [fn] (fn fn fn fn fn fn fn)) list)
14:13	clojurebot	(#<clojure.lang.PersistentList$1@f90a8b> #<clojure.lang.PersistentList$1@f90a8b> #<clojure.lang.PersistentList$1@f90a8b> #<clojure.lang.PersistentList$1@f90a8b> #<clojure.lang.PersistentList$1@f90a8b> ...)
14:13	justin_smith	haha
14:13	justin_smith	gfredericks: it's now reminding me of "Being John Malkovich"
14:14	justin_smith	but instead of crawling in to be Malkovich, you crawl into the weird little door and suddenly you are an anonymous function...
14:14	justin_smith	https://www.youtube.com/watch?v=Q6Fuxkinhug
14:14	andyf	self reference isn't what i used to be
14:15	justin_smith	classic scene
14:15	justin_smith	nor is semantic satiation
14:52	ghadishayban	about to release this tiny library of clojure 1.7 "helpers" https://github.com/ghadishayban/reducers
14:52	ghadishayban	more reducible sources, reduce-based ops and a couple other novel things
14:53	ghadishayban	would love to get some eyes on it
14:54	ghadishayban	inspired by some an musing from hiredman
14:55	ghadishayban	the implementation of select-keys with transducers becomes super nice (and fast):
14:56	ghadishayban	(defn select-keys
14:56	ghadishayban	[map keyseq]
14:56	ghadishayban	(into {} (keep #(find map %)) keyseq))
14:57	justin_smith	,(doc find)
14:57	clojurebot	"([map key]); Returns the map entry for key, or nil if key not present."
14:57	justin_smith	is that an optimization for get?
14:58	ghadishayban	it returns the whole MapEntry. sister function to get
14:58	justin_smith	oh, interesting
14:59	justin_smith	,(find [:a] 0)
14:59	clojurebot	[0 :a]
14:59	ghadishayban	,(conj {} [:a :b])
14:59	justin_smith	assuming that's odd
14:59	clojurebot	{:a :b}
14:59	gfredericks	useful for implementing plumbing.core/safe-get
14:59	gfredericks	or more generally, for doing both contains? and get in one lookup
15:01	ghadishayban	,(class (find {:a :b} :a))
15:01	clojurebot	clojure.lang.MapEntry
15:01	justin_smith	,(type (find [:a] 0))
15:01	clojurebot	clojure.lang.MapEntry
15:02	gfredericks	lifehack: to protect yourself against accidentally evaling a scratch file, put (don't load this) on the first line
15:02	gfredericks	I guess it works just as well without the parens
15:02	gfredericks	could even be englishified as "Don't load this."
15:02	justin_smith	alternatively (why did you load this file? you shouldn't have tried)
15:03	justin_smith	gfredericks: the bonus with the parens I think is that you would get the whole thing, not just the first invalid symbol
15:03	ghadishayban	,filter-key
15:03	clojurebot	#<CompilerException java.lang.RuntimeException: Unable to resolve symbol: filter-key in this context, compiling:(NO_SOURCE_PATH:0:0)>
15:03	ghadishayban	,clojure-version
15:03	clojurebot	{:interim true, :major 1, :minor 7, :incremental 0, :qualifier "master"}
15:03	justin_smith	gfredericks: err... I guess not
15:05	ghadishayban	(defn filter-key [keyfn pred coll] (into (empty coll) (filter (comp pred keyfn)) coll))
15:05	ghadishayban	,(defn filter-key [keyfn pred coll] (into (empty coll) (filter (comp pred keyfn)) coll))
15:05	clojurebot	#'sandbox/filter-key
15:06	ghadishayban	(filter-key val even? {:a 2 :b 1 :c 4 :d 5})
15:06	ghadishayban	,(filter-key val even? {:a 2 :b 1 :c 4 :d 5})
15:06	clojurebot	{:c 4, :a 2}
15:06	ghadishayban	,(filter-key key string? {:a 2 :b 1 "HI" 4 :d 5})
15:06	clojurebot	{"HI" 4}
15:06	justin_smith	oh, that's very nice
15:07	ghadishayban	transducers are the shit
15:07	ghadishayban	that's all using transients
15:07	justin_smith	so I am seeing
15:08	ghadishayban	similarly,
15:09	ghadishayban	,(filter-key :a string? [{:a 3} {:a "foo"}])
15:09	clojurebot	#<CompilerException java.lang.RuntimeException: Unable to resolve symbol: filter-key in this context, compiling:(NO_SOURCE_PATH:0:0)>
15:09	ghadishayban	guess that var expired?
15:09	justin_smith	clojurebot protects us from ourselves with periodic automatic resets
15:09	gfredericks	~transducers \|are\| the shit
15:09	clojurebot	Ack. Ack.
15:20	ghadishayban	what do people normally call the find-first function:
15:20	ghadishayban	(first (filter pred coll))
15:21	bbloom_	ghadishayban: i usually just do (let [[x] (filter pred coll)] ...
15:21	ghadishayban	slick
15:22	ghadishayban	i called it any...and i hate it
15:22	ghadishayban	https://github.com/ghadishayban/reducers/blob/master/src/ghadi/reducers.clj#L66-L80
15:22	bbloom_	ghadishayban: i've seen it called "one" in ORMs ಠ_ಠ
15:23	ghadishayban	let's call it some!
15:23	ghadishayban	jk
15:25	SagiCZ1	if i have a custom loop in which i am building a list (adding an element to it in each iteration) is there any way to make this lazy?
15:25	justin_smith	cinderella (like how the prince lines up all the women and takes the first one that can wear the shoe)
15:25	ghadishayban	nice
15:26	justin_smith	SagiCZ1: use a function that self calls within lazy-seq
15:26	bbloom_	SagiCZ1: just use a recursive call and lazy-seq
15:26	bbloom_	justin_smith: heh
15:26	SagiCZ1	(doc lazy-seq)
15:26	clojurebot	"([& body]); Takes a body of expressions that returns an ISeq or nil, and yields a Seqable object that will invoke the body only the first time seq is called, and will cache the result and return it on all subsequent seq calls. See also - realized?"
15:26	SagiCZ1	this one right?
15:26	justin_smith	right
15:26	justin_smith	@grim lazy-seq
15:26	SagiCZ1	k thanks
15:26	justin_smith	$grim lazy-seq
15:26	justin_smith	not in yet, OK
15:27	SagiCZ1	what is grim?
15:27	justin_smith	it would have found this http://grimoire.arrdem.com/1.6.0/clojure.core/lazy-seq/
15:27	ghadishayban	SagiCZ1: depending on what you're doing, look at iterate
15:27	justin_smith	has some examples
15:27	justin_smith	oh yeah, iterate sometimes works - depends
15:28	ghadishayban	i added a reducible iterate that little reducers lib: https://github.com/ghadishayban/reducers/blob/master/src/ghadi/reducers.clj#L43-L50
15:28	SagiCZ1	and is it generally a good idea to make your functions return lazy seqs? i mean i just end up rewriting it to use lazy seq..
15:28	justin_smith	SagiCZ1: in some cases lazy-seqs are very handy
15:30	ghadishayban	SagiCZ1: though i will say, almost in 100% of cases there a way using clojure seq functions (like iterate, map, mapcat, filter) without having to call lazy-seq manually
15:30	ghadishayban	i mean, to express a loop
15:30	ghadishayban	if you can paste your loop to refheap...
15:31	SagiCZ1	ghadishayban: but loop is specifically for cases where you cant express it another way
15:32	ghadishayban	unless you can't see that there is another way to express it :)
15:32	SagiCZ1	ghadishayban: which might be very possible.. i have no problem pasting it on refheap, maybe you can take a look if you want
15:32	ghadishayban	usually if you're iterating simultaneously through two collections, then loop is your only option
15:33	amalloy	ghadishayban: in many of those cases, map is fine
15:33	amalloy	i definitely wouldn't say "usually"
15:33	SagiCZ1	i guess i am doing all kinds of weird stuff https://www.refheap.com/92926
15:35	justin_smith	as-is, that could be a reduce on ticks
15:35	justin_smith	where events is the accumulator
15:36	SagiCZ1	justin_smith: is reduce lazy?
15:36	justin_smith	and uncompleted bars is also an accumulator
15:36	justin_smith	no
15:37	SagiCZ1	you are just saying i dont necessarily need loop
15:37	justin_smith	it could also be a (:events (last (take-while pred (iterate f [ticks bars]))))
15:37	justin_smith	or something like that
15:37	justin_smith	definitely don't need loop
15:38	ghadishayban	justin_smith: that's kinda hard to grok
15:38	justin_smith	there may be a more straightforward way to use iterate there actually
15:38	justin_smith	ghadishayban: yeah, it's a mess, sorry
15:39	SagiCZ1	i just need to make it lazy..
15:40	justin_smith	SagiCZ1: it would be fairly straightforward to make it lazy with reductions, where you would have completed-bars and uncomplete-bars for each step
15:41	SagiCZ1	i thought reduce is not lazy?
15:41	SagiCZ1	reductions not= reduce
15:42	SagiCZ1	(doc reductions)
15:42	clojurebot	"([f coll] [f init coll]); Returns a lazy seq of the intermediate values of the reduction (as per reduce) of coll by f, starting with init."
15:43	SagiCZ1	i need to learn this stuff.. i will probably head to 4clojure, before i tackle this big loop
15:45	justin_smith	SagiCZ1: something like this I think https://www.refheap.com/92929
15:46	justin_smith	no wait...
15:46	SagiCZ1	wow, thanks for taking the time to write that.. i will look into it
15:46	justin_smith	I just saw a mistake in that actually
15:48	justin_smith	SagiCZ1: updated, I am sure it is still imperfect https://www.refheap.com/92929
15:48	justin_smith	but may be a good starting point
15:49	justin_smith	SagiCZ1: the big picture is that at each step it generates a two element vector of the events (completed bars) and the bars (the ones still being used) and you get a lazy-seq with one pair of these generated from each tick
15:49	justin_smith	(or that is what it does if it isn't still buggy)
15:50	amalloy	SagiCZ1's loop looked a lot like a filter and/or a mapcat to me; i don't have time to write it up atm, but i don't see any steps depending on the results of previous steps
15:50	justin_smith	amalloy: it moves things between completed / uncompleted
15:50	justin_smith	well, one way
15:50	amalloy	okay
15:51	justin_smith	it does an update of the previous "completed" bars at each step
15:51	justin_smith	that's why I think it need accumulators
15:52	justin_smith	but I have been known to use reduce / reductions when a filter or mapcat would do, so it's worth a second check on that
15:53	justin_smith	SagiCZ1: one trivial change I did is replace #(:complete %) with :complete in a couple places - in that context it was identical
15:54	justin_smith	but I tried to keep each of the steps of the core logic the same as your version, so the adaptation is clear
15:55	justin_smith	*should be clear, barring more mistakes on my part
15:58	SagiCZ1	amalloy: in one iteration some bars get completed (and they get replaced by new bars) but others have to be past to the next step
15:58	SagiCZ1	justin_smith: thanks again, i will try it out once i get back to it
15:59	justin_smith	np, I was just spinning my wheels before trying a big db migration on my scratch db, that I am procrastinating on because it will probably fail and I will need to reset the db again...
15:59	justin_smith	:)
16:11	SagiCZ1	:)
16:19	justin_smith	well, I sure did call that one, time to wipe the test db again!
16:58	donbonifacio	I have a hash, with a lazy-seq somewhere, how can I find it
17:00	justin_smith	so it's a hash map with a lazy-seq inside it?
17:00	justin_smith	do you have a handle to that hash-map?
17:01	justin_smith	or maybe the better question is - where did this hash map and lazy seq come from, and what do you expect to find in them?
17:03	donbonifacio	I have a hash that I'm passing to monger, and it's complaining clojure.lang.LazySeq cannot be cast to java.lang.String
17:04	donbonifacio	I do have a key that's an array, I'm gessing that it can't convert that to a string and maybe it's calling it a LazySeq
17:04	justin_smith	I doubt it
17:05	justin_smith	you could use clojure.walk/postwalk
17:09	justin_smith	,(clojure.walk/postwalk (fn [el] (when (isa? (type el) clojure.lang.LazySeq) (println el)) el) {:a 0 :b 1 :c {:d (range 10)}})
17:09	clojurebot	#<ClassNotFoundException java.lang.ClassNotFoundException: clojure.walk>
17:10	justin_smith	maybe something like that? but there is probably a more elegant way to do it
17:10	justin_smith	,(require 'clojure.walk)
17:10	clojurebot	nil
17:10	justin_smith	,(clojure.walk/postwalk (fn [el] (when (isa? (type el) clojure.lang.LazySeq) (println el)) el) {:a 0 :b 1 :c {:d (range 10)}})
17:10	clojurebot	(0 1 2 3 4 ...)\n{:a 0, :b 1, :c {:d (0 1 2 3 4 ...)}}
17:18	justin_smith	,(do (clojure.walk/postwalk (fn [el] (when (isa? (type el) clojure.lang.LazySeq) (println el)) el) {:a 0 :b 1 :c {:d (range 10)}}) nil) ; a little more clear maybe?
17:18	clojurebot	(0 1 2 3 4 ...)\n
17:27	irctc	Would anyone have any idea why my tiny Clojure server will not read from a Socket before the Python Client closes its own socket. -> gist https://gist.github.com/KristoKoert/3d1aa3ccd90a8bfcc341
17:30	justin_smith	irctc: how do you know the clojure code is not reading?
17:32	justin_smith	are you developing inside an editor by any chance? because your defns are in the wrong order
17:33	irctc	I had a load of printlns in between every step, The server executed till the comment i left. At the same time the python server continued sending its message until I exit the python script and once I exit it all the messages are recieved and the Clojure program continues as expected (will read every time), but will not hear the client if I try reconnecting.
17:34	irctc	It might be that my python script is wrong as well..
17:34	irctc	Inside emacs, I am just trying it out, so evaling :)
17:35	justin_smith	irctc: using cider?
17:35	justin_smith	look for an nrepl-connection buffer - that should get your .println output
17:36	irctc	Yes, cider.
17:36	justin_smith	yeah, the way emacs/cider/clojure handle stdout is way weird, some things from threads go in the wrong buffer due to dynamic binding and how that works when spawning threads
17:37	irctc	Actually I DO get all the messages and I have the cider repl open and see them in there. But the problem is that the messages only come through AFTER I stop the Python script. For whatever reason..
17:37	irctc	And all of them at the same time.
17:39	justin_smith	oh, sorry, yeah
17:39	justin_smith	is that python code sending full lines?
17:40	justin_smith	because .readLine might be waiting for a newline
17:40	justin_smith	maybe socket.send does not insert newlines?
17:40	irctc	Oh? I will try that right now!
17:40	justin_smith	actually I would be surprised if it did
17:45	irctc	Nice, it worked! Great, a really simple mistake... Thanks guys :)
17:49	justin_smith	np
18:22	justin_smith	is there a paredit command that is like C-t but for list elements and not characters?
18:22	justin_smith	so if I have [a b \|c d] and I run that command, it should become [a c b \|d]
18:23	Bronsa	justin_smith: isn't that transpose-sexps?
18:24	justin_smith	Bronsa: probably, I didn't find it on my paredit cheat-sheet
18:24	Bronsa	justin_smith: don't think it's a paredit function
18:25	justin_smith	Bronsa: yeah, it kind-of works, but totally doesn't respect hash-map structure
18:25	justin_smith	but better than nothing
18:25	Bronsa	justin_smith: yeah looks like it's in emacs and bound to C-M-t
18:25	justin_smith	yeah
18:27	annelies	oh the joy of writing code in Java
18:49	amalloy	justin_smith: doesn't respect hash-map structure how?
18:49	justin_smith	it transposes keys and values separately, not as a pair
18:49	justin_smith	not that it would be reasonable to expect that I guess
18:50	justin_smith	maybe I will write a nice dwim that moves key value pairs forward and back in hashmap literals
18:50	justin_smith	and otherwise acts just like transpose-sexps
19:38	annelies	I am going to sleep ladies and gentlemen.
19:38	Bronsa	bye
19:38	annelies	goodbye
19:41	annelies	There is get and get-in, assoc and assoc-in, and update-in, but why not update?
19:41	andyf	annelies: There will be in Clojure 1.7
19:41	Bronsa	annelies: update has been added in 1.7
19:41	annelies	Nice. :)
19:42	andyf	you ask interesting questions while you sleep :)
19:43	annelies	I also really wish numerator and denominator worked on integers. :c There's a bug report of it already though.
19:43	andyf	have you voted for it?
19:43	annelies	Yeah
19:44	andyf	Then except for encouraging others to vote on it and writing a patch that works, you've done all you can :)
19:45	Bronsa	in my experience, a ticket with no patch will hardly get considered unless it's a serious bug
19:49	andyf	Bronsa: I think it matters more whether Rich or a screener like Alex think the description is something they agree is a problem, not whether there is currently a patch.
19:50	andyf	A screener triaging a ticket, or Rich vetting one, seem to me to have little to do with the presence/absence of a patch, but I'm guessing based on watching, not knowing.
19:50	Bronsa	andyf: I would like to agree with you but I'm pretty sure there is a large number of valid tickets that have never been seen by Rich or by any screener
19:51	andyf	Alex Miller has seen every one multiple times, I'm sure.
19:52	andyf	Summer 2013 he checked and/or updated the state of every single open ticket, and he's vetted about 1/5 of the open ones.
19:52	andyf	sorry, triaged, not vetted
19:52	justin_smith	andyf: is 0.1.5 the latest eastwood available from maven?
19:52	andyf	justin_smith: yes
19:52	justin_smith	cool, thanks
19:52	justin_smith	so this does not have the from-repl stuff you talked about recently, right?
19:52	andyf	You can check on clojars.org for any project hosted there what all version are that have been released, fyi, but I don't mind answering.
19:53	justin_smith	OK
19:53	andyf	It can be run from the REPL, and you don't need Leiningen.
19:53	justin_smith	oh, cool
19:53	andyf	Instructions here: https://github.com/jonase/eastwood#running-eastwood-in-a-repl
19:53	andyf	With I hope appropriate and not-too-scary warnings
19:54	justin_smith	andyf: I had assumed, given the big version difference between github and clojars, that the newer feature was not available or maybe I just wasn't finding it
19:54	andyf	Don't do it in a live production JVM is the most important warning.
19:54	justin_smith	right, I wouldn't need that anyway, thanks
19:54	andyf	Oh, you mean the 0.2.0-SNAPSHOT on github?
19:54	justin_smith	right
19:55	justin_smith	that's what confused me
19:55	andyf	That is not binding, but I am hoping it encourages me to add the feature for source code annotations to disable linters on a per-file and/or per-expression basis, which I consider worth bumping the version to 0.2.0 when released.
19:56	annelies	well, time to really sleep
19:56	annelies	goodbye! <3
19:56	andyf	I'm doing development on master. You have to checkout a version-specific tag if you want to see source code for a specific release (or unzip the jar)
19:57	Bronsa	andyf: eh well, updating the status of a ticket doesn't mean it has been considered, it's just maintainance from my POV. there are a lots of "dead" tickets (i.e. that see no activity whatsoever) in jira
19:58	andyf	I'm gradually becoming accustomed to taking the long view, e.g. 5 years out :)
19:58	justin_smith	andyf: thanks. This message is confusing (caused by a misnamed file that I forgot to delete) - is it worth filing a ticket for? https://www.refheap.com/92941
19:58	Bronsa	andyf: I'm not criticizing Alex's work btw, the process is just really frustrating sometimes
19:59	andyf	Understood. Paraphrasing Sir Lawrence of Arabie from the movie, the trick is not minding that it takes the time it does :)
19:59	andyf	Arabia, even.
20:00	Bronsa	andyf: it's counterproductive though. Say I open a ticket and attach a patch and that ticket doesn't get considered until 2 years later when the patch doesn't apply anymore
20:00	Bronsa	in the meantime I've lost interest in clojure and/or don't use it anymore for my work and I'm not going to update the patch, and the ticket becomes stale
20:00	andyf	Bronsa: That is the same situation we would be in even if all of the other 400 open tickets were considered before that ticket's patch -- most likely it wouldn't apply cleanly any more
20:01	justin_smith	andyf: update with suggested replacement message https://www.refheap.com/92941
20:02	andyf	justin_smith: Sure, open a ticket for that. The message you see now is correct, but I agree a bit verbose for the common special case you have.
20:02	Bronsa	andyf: I'm not sure it would be this bad. consider patch 1 that affects file a and patch 2 that affects the same file is written 3 months later
20:03	Bronsa	andyf: if patch 1 has been merged within the 3 months period, patch 2 will be writte on top of patch 1 and will apply cleanly
20:03	justin_smith	andyf: the "has namespace" / "should have namespace" are identical, which I thought may have been a bug. I'll file it as a suggestion.
20:03	Bronsa	andyf: if patch 1 has not been merged, patch 1&2 will conflict and once one gets merged the other will not apply anymore
20:04	andyf	justin_smith: I'd call it a confusing message, to be sure, and worth a special case in the code that prints the messages.
20:04	andyf	justin_smith: that sentence fragment combined with the "or should be in file" are technically correct, where it is really the second part after the or that is true in this instance. I'm all for clearer warning messages.
20:05	justin_smith	cool, thanks
20:06	andyf	Bronsa: We are not alone in wishing the process went faster sometimes. To me, the heart of the issue is: our wishes do not trump someone else's free will in choosing what they do with their time.
20:08	andyf	Another way of looking at it is this: ~8 years after first working on the project, the creator still spends a chunk of his free time every month enhancing it. i.e. it is not abandoned.
20:10	andyf	And, he adds things to it like transducers, rather than restricting himself to considering problem reports that have been created by others.
20:11	Bronsa	andyf: I envy your ability to feel this way knowing the amount of time you spend around JIRA and noticing the (mostly) lack of activity around it by any core member other than Alex
20:12	andyf	Bronsa: I would not have spoken like this 2 years ago. It is an acquired attitude :)
20:13	Bronsa	andyf: I don't see your last point as a positive thing. To me that shows exactly how little issues reported by community members are valued
20:13	andyf	In the mean time, I think you are having a big impact on projects like core.typed, core.async, Eastwood, and whatever else tools.analyzer.* are getting use in.
20:15	andyf	Bronsa: I don't know exactly how much time is spent by who on what, but I get the distinct impression that if all they did was focus on tickets from community members, they wouldn't have time/energy left for adding cool new stuff.
20:16	andyf	Bronsa: Out of curiosity, do you know of any other projects besides the ones I mentioned using tools.analyzer?
20:17	Bronsa	andyf: crossclj uses t.a AFAIK
20:17	andyf	Oh, yeah. That site is amazing.
20:19	andyf	Francesco even found and fixed an issue I reported recently, where many of the "this var is used in places x, y, z, ..." had a bug in it.
20:19	Bronsa	it is indeed. my only complaint is that the UI feels a bit too "heavy" sometimes
20:22	Bronsa	andyf: ah, nrepl-refactor or however it's called uses t.a too. not sure if in a released version or a still in dev
20:25	andyf	I bet the list will grow as more people think of uses for it. Hats off to you, my friend.
20:26	justin_smith	(inc andyf)
20:26	lazybot	⇒ 5
20:26	justin_smith	eastwood is awesome, thanks
20:26	justin_smith	I just regret I didn't start using it sooner
20:27	Bronsa	(inc andyf)
20:27	lazybot	⇒ 6
20:28	andyf	Got to go for a while. Talk to you folks later.
20:28	Bronsa	have some internet points. I'll need yo buy you a beer if we ever get the chance to meet, for having my back when I break things
20:30	andrewhr	Bronsa: maybe a stupid question, but there is any work around a t.e.js? found only the t.e.jvm
20:31	Bronsa	andrewhr: no and I honestly have no interested in forking the cljs compiler to adapt its emitter to compiler t.e.js's AST rather than cljs.analyzer's one
20:32	andrewhr	you don’t have any interest or the community don’t see any value with that?
20:33	nonuby	destructing question, i dont what the difference is between defn x [handlers] and defn x [[& handlers]]
20:33	andrewhr	btw, I’m just asking to you bc your work with t.e.jvm
20:34	andrewhr	not want to mean anything bad, please
20:35	Bronsa	andrewhr: I don't have interest nor time, and I guess neither does the community. There's not much value in another cljs compiler, t.a.js otoh is valuable because it is (in my biased opinion) a lot more powerful than cljs.analyzer
20:35	amalloy	nonuby: the second version is just silly
20:36	amalloy	you are correct in implying that there is no difference
20:36	Bronsa	amalloy: there is though, the first will accept "1", the second won't
20:36	amalloy	well, yes
20:36	Bronsa	it's a silly way to assert (coll? arg)
20:36	amalloy	and the second will convert [] to nil
20:36	Bronsa	wut?
20:36	nonuby	so its like some form of weak typing checking... ah you said first
20:36	amalloy	won't it?
20:37	Bronsa	no idea
20:37	amalloy	,((fn [[& xs]] xs) [])
20:37	clojurebot	nil
20:37	amalloy	Bronsa: because & destructuring never returns an empty seq, only nil or non-empty
20:37	Bronsa	TIL
20:37	nonuby	amalloy, cool. thanks just something i noticed on compojure.core/routes
20:38	andrewhr	Bronsa: thanks. just want to know how the clj(s) community feels about that
20:38	Bronsa	amalloy: do you happen to know if that was a conscious decision or an accident of the impl?
20:38	amalloy	Bronsa: i believe it's a legacy of the time when there was no such thing as a non-empty seq
20:39	Bronsa	and/or if there's an obvious reason why it doesn't return () that I'm missing
20:39	amalloy	it's a decision that i really wish we could undo
20:39	amalloy	er, no such thing as an empty seq
20:40	Bronsa	andrewhr: well I'm not the right person to ask such a thing then :) I'm not really part of the cljs sub-community
20:41	amalloy	the problem is that it means you should never use & xs destructuring in a lazy function. consider this reasonable implementation of map: (fn map [f xs] (lazy-seq (when-let [[x & xs] (seq xs)] (cons (f x) (map f xs)))))
20:41	amalloy	it looks correct, but because xs will never be nil, you end up forcing one more element of the input collection than the user asks for
20:41	andrewhr	Bronsa: still think it’s a valulable opinion :)
20:43	andrewhr	another shot for you: t.a is capable of doing some kind of incremental analysis? let’s say - to use it for making some kind of code highlight for example
20:43	Bronsa	amalloy: makes sense, thanks
20:47	Bronsa	andrewhr: t.a assumes fully evaluated env but there are ways to analyzing code w/o evaluating it, even though that requires a bit of configuration & the analysis might be inaccurate
20:47	Bronsa	andrewhr: not sure if that's what you were asking me though
20:49	andrewhr	Bronsa: so you will only be able to really analyze code in a “live runtime”, if I get it right
20:49	andrewhr	(in a precise way)
20:49	Bronsa	andrewhr: in t.a.jvm yes. for cljs it's a bit different because it has no resident compiler & reified namespaces
20:50	andrewhr	got it
20:50	andrewhr	thanks again!
20:51	Bronsa	andrewhr: silly example, "(defmacro foo [] (list 'def 'bar 1)) (foo) bar", the analyzer has no way to know that "bar" refers to a var if you don't evaluate the defmacro expr and it's invocation before analyzing the symbol "bar"
20:53	Bronsa	andrewhr: I mean, there are certainly techniques it could use to figure it out in this case, but that's out-of-scope for t.a
21:01	andrewhr	Bronsa: I see. requiring a live environment will not be a true problem for what I have in mind
21:08	puredanger	Bronsa (and andyf ) : just browsing the back chat. just fyi, the ticket situation is frustrating for me too.
21:08	dc_	whats the best way to combine two lists in clojure like this: [1 2 3] [4 5 6] => [[1 4][2 5][3 6]]
21:08	dc_	like is there a function that does that?
21:08	godd2	interleave?
21:08	hyPiRion	,(apply map list [[1 2 3] [4 5 6]])
21:09	clojurebot	((1 4) (2 5) (3 6))
21:09	dc_	ahh ok yep, that's what i'm looking for
21:09	hyPiRion	If you want vectors
21:09	hyPiRion	,(apply mapv vector [[1 2 3] [4 5 6]])
21:09	clojurebot	[[1 4] [2 5] [3 6]]
21:09	dc_	godd2 hipirion: thanks
21:09	hyPiRion	np
21:10	Bronsa	puredanger: yeah I don't find it hard to believe that. I'm sorry if you've been named in my small rant but I assure you I that I (and I hope to talk for most of the community) really apprecciate your work
21:10	puredanger	I do what I can
21:11	godd2	,(map vector [1 2 3] [4 5 6])
21:11	clojurebot	([1 4] [2 5] [3 6])
21:11	godd2	oh I see that doesn't return a vector
21:12	godd2	,(mapv vector [1 2 3] [4 5 6])
21:12	clojurebot	[[1 4] [2 5] [3 6]]
21:25	smnirven	okay folks, let's say I have a sequence of maps, and I want to call a certain function once for every map in the sequence, but for use in the -> macro
21:27	smnirven	any ideas on how i might accomplish that?
21:28	Bronsa	smnirven: you want to map inside a -> expression?
21:28	smnirven	yeah something like that
21:29	Bronsa	you can do (-> coll ... (as-> coll (map f coll)) ..)
21:29	TEttinger	(doc as->)
21:29	Bronsa	smnirven: assuming you can't use ->>
21:29	clojurebot	"([expr name & forms]); Binds name to expr, evaluates the first form in the lexical context of that binding, then binds name to that result, repeating for each successive form, returning the result of the last form."
21:30	justin_smith	,(-> [{:a 0 :b 1} {:a 1 :b 2}] (#(map :a %))) ; another option
21:30	clojurebot	(0 1)
21:31	TEttinger	,(-> [{:a 0 :b 1} {:a 1 :b 2}] ((partial map :a))) ; yet another option
21:31	clojurebot	(0 1)
21:32	smnirven	ahh, partial might be the ticket here
21:32	Bronsa	justin_smith: I find that really ugly
21:33	justin_smith	,(-> [{:a 0 :b 1} {:a 1 :b 2}] (->> (map :a))) ; yet another
21:33	clojurebot	(0 1)
21:33	Bronsa	whenever I find myself wanting to (-> .. (#(..))) I just lift the lambda in a let over the -> expr
21:33	TEttinger	that last one looks like a winner, justin_smith
21:34	justin_smith	TEttinger: and of course it can bump up a level again if you need -> again
21:34	Bronsa	and I also tend to avoid nesting ->/->>/doto as that gets unreadable pretty fast :P
21:34	smnirven	let's say the collection coll [{:a 1} {:a 2}]
21:35	smnirven	I want to insert the same function in an existing thread macro once for each map in that collection
21:35	smnirven	(-> orig (f1) (f2 {:a 1}) (f2 {:a 2})
21:36	smnirven	trying to figure out how to do that with any number of maps in that collection
21:36	justin_smith	smnirven: that does not work in general unless you know the maps (or at least how many there are) when the macro is expanded
21:36	TEttinger	that sounds like a different use case
21:37	Bronsa	smnirven: are you sure you want (f2 (f2 (f1 orig) {:a 1}) {:a 2})?
21:38	smnirven	Bronsa: yep
21:40	Bronsa	that's (reduce f2 (f1 orig) [{:a 1} {:a 2}]), I wouldn't really insert it in a -> expr
21:40	smnirven	there's a pretty good chance im attacking this in the wrong way entirely -- basically im trying to compose a sqlkorma select with the possibility of multiple joins
21:55	arrrms	What are people's opinions on the Web Development with Clojure book? There are only two Amazon reviews (http://www.amazon.com/Web-Development-Clojure-Build-Bulletproof/dp/1937785645/ref=sr_1_1?ie=UTF8&qid=1415500923&sr=8-1&keywords=clojure+web+development)
22:19	godd2	Is there a way to have lein repl print out transients in a prettier way?
22:20	gfredericks	godd2: check out print-method
22:20	gfredericks	,(transient [1 2 3])
22:20	clojurebot	#<TransientVector clojure.lang.PersistentVector$TransientVector@13c422e>
22:21	gfredericks	,(defmethod print-method clojure.lang.TransientVector [tv pw] (print-method (into [] (map #(get tv %) (range (count tv)))) pw))
22:21	clojurebot	#<CompilerException java.lang.ClassNotFoundException: clojure.lang.TransientVector, compiling:(NO_SOURCE_PATH:0:0)>
22:21	gfredericks	,(defmethod print-method clojure.lang.PersistentVector$TransientVector [tv pw] (print-method (into [] (map #(get tv %) (range (count tv)))) pw))
22:21	clojurebot	#<MultiFn clojure.lang.MultiFn@18eaab5>
22:21	gfredericks	,(transient [1 2 3])
22:21	clojurebot	[1 2 3]
22:21	godd2	oh wow
22:21	gfredericks	or if you want it to be less ambiguous
22:21	godd2	did you just change clojurebot for good? (or at least for a while)
22:22	gfredericks	,(defmethod print-method clojure.lang.PersistentVector$TransientVector [tv pw] (.write pw "#transient ") (print-method (into [] (map #(get tv %) (range (count tv)))) pw))
22:22	clojurebot	#<MultiFn clojure.lang.MultiFn@18eaab5>
22:22	gfredericks	,(transient [1 2 3])
22:22	clojurebot	#transient [1 2 3]
22:22	godd2	I like that even more
22:22	gfredericks	godd2: I think it'll reboot after 10 minutes or something
22:23	godd2	Where should I put code for lein repl to run as it's booting up?
22:23	godd2	in a dependency?
22:24	justin_smith	godd2: clojure will load user.clj
22:24	justin_smith	src/user.clj for example
22:24	justin_smith	more detail here http://dev.solita.fi/2014/03/18/pimp-my-repl.html
22:25	godd2	yay!
22:25	minaminamina	Hey there! I was trying to write a cljs library that I could deploy to clojars, and require in another project. The library is written, it's simple, and it works, but when I try to require it somewhere else, the only visible namespace is my-namespace.core
22:25	minaminamina	Would anyone mind looking at the project.clj file to see what I'm doing wrong?
22:25	smnirven_	link plz
22:26	minaminamina	https://github.com/minasmart/squelch/blob/master/project.clj
22:27	minaminamina	including it in the dependencies section of another project doesn't produce errors, but trying to require anything other than squelch.core makes it complain: WARNING: No such namespace: squelch.audio-context at line 1...
22:27	justin_smith	minaminamina: you have - in your file names
22:28	smnirven_	yep thats it
22:28	justin_smith	clojure cannot find files named that way
22:28	smnirven_	underscores to the rescue
22:28	minaminamina	OK, I was wondering about that. Should they be underscored?
22:28	justin_smith	rename audio-context.clj to audio_context.clj
22:28	minaminamina	Then should namespaces be named with hyphens or underscores?
22:28	justin_smith	yeah, the namespace can keep the same name, just rename all the files
22:28	smnirven_	filenames should be underscored, but the namespace names can still be hypens
22:28	justin_smith	so ns is audio-context, file is audio_context
22:29	minaminamina	For namespace naming, what is more typical? Hyphen or underscore?
22:29	justin_smith	minaminamina: there is a nice tool called eastwood (a lein plugin) that detects these kinds of issues
22:29	justin_smith	hyphen is preferred for namespaces
22:29	justin_smith	but it has to be underscore in the file
22:29	minaminamina	OK, cool! And thanks Justin! I'll check out that plugin!
22:29	minaminamina	Thanks alot!
22:30	justin_smith	np
22:49	grandy	i'm new to clojure and a bit confused about how to use sessions in compojure, anyone know of a public repo that does this?
22:50	godd2	how do you get the keys from a transient hashmap?
22:50	godd2	,(keys (transient {:a 1 :b 7}))
22:50	clojurebot	#<IllegalArgumentException java.lang.IllegalArgumentException: Don't know how to create ISeq from: clojure.lang.PersistentArrayMap$TransientArrayMap>
22:52	justin_smith	grandy: https://www.refheap.com/92948 you can use this definition as a middleware foar a cookie session
22:53	grandy	justin_smith: thanks!
22:53	justin_smith	that uses ring.middlware.session/wrap-session
22:53	justin_smith	there are other options for in-memory rather than server sessions
22:53	grandy	justin_smith: dumb question but how do I set the session to {:hello "world"}
22:53	justin_smith	of course you probably want to fix the key, cookie-name, max-age
22:54	verma	how do I run the jar chestnut gives me? just doing a java -jar app.jar doesn;t seem to work,
22:54	justin_smith	grandy: in your handler create a response map, with {:body "text of page" :status 200 :session {:hello "world}}
22:54	verma	it just drops me into a clojure repl
22:54	grandy	justin -- I tried that but then I removed it and refreshed the page and it was gone from the session data,
22:55	justin_smith	verma: you can specify a class / method to run, if you have a -main defined and aot compile that namespace
22:56	justin_smith	grandy: with the middleware set up properly, you should see the same data come in under :request
22:56	grandy	hmm
22:56	justin_smith	grandy: you need to watch out for accidentally attaching a null :session in between of course
22:56	verma	justin_smith, :uberjar profile says :aot :all, so I guess it'd be aot compiled, I am also not sure what the command line would look like
22:57	justin_smith	verma: if your main ns is set up properly (such that lein run works) the compiled jar will work too
22:57	grandy	justin_smith: this is my handler, do you see anything obviously wrong with it? quite possible there is something very dumb going on: https://gist.github.com/mmmurf/0cfe722ad60c47c34b1f
22:57	verma	justin_smith, oh let me try lein run
22:57	justin_smith	you aren't returning the right thing
22:58	justin_smith	grandy: you are passing the session as the response map
22:58	justin_smith	you want to pass the session INSIDE the response map
22:58	verma	justin_smith, does the class with -main needs to have :gen-class, I was just wondering since chestnut didn't do that
22:58	grandy	justin_smith: hmm I think I have to review the signatures that are going on there... I'll try w/ a simple text response
22:58	justin_smith	grandy {:body [:body ...] :session (assoc (:session params) :count 1)}
22:59	justin_smith	grandy: you need to put what you were previously returning into the :body key
22:59	justin_smith	right now, [:body ...] inside common is doing nothing, it's just a data literal that is not used or returned by the function
22:59	grandy	justin_smith: ahh so {:body is not a hiccup function it's a map for ring?
23:00	amalloy	grandy: yes
23:00	justin_smith	grandy: yes, ring accepts multiple return values
23:00	amalloy	justin_smith: how do you mean?
23:00	justin_smith	if you specify a string, that becomes the page body, if you return a map, the :body key is used for that
23:00	justin_smith	amalloy: just that it is polymorphic on what you return to it
23:00	grandy	justin_smith: ahh ok, so does this mean that in my compojure code all handlers that update hte session need to return a map?
23:01	justin_smith	right
23:01	justin_smith	amalloy: I should have said "accepts multiple return types"
23:01	grandy	justin_smith: ahh ok i see, now it is starting to make sense
23:02	justin_smith	grandy: and I was wrong above, you want {:body (common [:body ...]) :session ...} in the response map
23:02	justin_smith	or bind the rendered result of common in a let, of course
23:02	grandy	justin_smith: ok cool I think I've done that...
23:03	grandy	justin_smith: https://gist.github.com/anonymous/586bf33aea6347999969
23:03	justin_smith	verma: you can specify an arg that says run clojure.core and then another arg that tells clojure.core to run a specific function in a specific ns - one moment, I need to find it
23:04	justin_smith	grandy: yeah, that looks about right
23:04	verma	justin_smith, nice! I actually tried to run lein run and it had problems, so I fixed those and running a lein uberjar right now
23:04	verma	51seconds to compile clojurescript :(
23:05	grandy	justin_smith: oddly it's not persisting
23:06	justin_smith	grandy: so :count 1 is not coming in on the next load?
23:06	grandy	justin_smith: correct, not if I comment out line 8 above
23:07	justin_smith	grandy: and you have the ring-session middleware in place?
23:07	grandy	justin_smith: in other words, the line that prints the session (line 5 above) prints {}
23:07	grandy	justin_smith: [ring.middleware.session :refer :all]
23:07	justin_smith	that requires the session, are you putting it in your middleware?
23:07	grandy	https://www.irccloud.com/pastebin/INl3FSu0
23:08	grandy	I think so, see the paste
23:08	justin_smith	OK, you might want add some arguments to wrap-session
23:08	justin_smith	also check in your browser if the cookie is being created
23:08	grandy	justin_smith: ahh good idea
23:09	justin_smith	maybe create an unencrypted cookie while debugging
23:09	justin_smith	verma: java -cp foo.jar clojure.main -m foo
23:09	justin_smith	where foo/-main is the main function
23:10	justin_smith	verma: you may not need that, but the advantage there is you don't need any aot for that to work
23:10	justin_smith	clojure finds and loads your code
23:11	zerkms	guys, could you please give me some hints about how idiomatically implement a file reader that would read all the lines that are added in runtime (which is more or less obvious) with ability to gracefully stop it
23:14	justin_smith	zerkms: basic idea is to create a file reader using clojure.java.io (io/reader (io/file "name")) and then you have a few options, probably easiest is to put it in a future, (def reader-thread (future (while (not (.isInterrupted (Thread/currentThread))) (.readLine reader))))
23:14	justin_smith	then you can call (future-cancel reader-thread) if you want it to stop
23:14	justin_smith	and probably you want to do something with the return value of .readLine of course :)
23:15	zerkms	I've head similar thoughts
23:15	zerkms	but
23:15	zerkms	.readLine is blocking
23:15	justin_smith	yeah, put it in a future
23:15	zerkms	what? (.readlLine reader)?
23:15	justin_smith	zerkms: the whole loop, like I did above
23:15	grandy	justin_smith: hmm do you see anything wrong w/ this?
23:15	grandy	https://www.irccloud.com/pastebin/rqHj35ln
23:16	justin_smith	or, use polling and non-blocking read
23:16	justin_smith	polling is guaranteed more complex though, of course
23:17	justin_smith	grandy: that isn't a valid key I don't think - the number of X in my example was exactly the number of characters that need to be in the key
23:17	zerkms	I see, so in your solution you don't immediately terminate .readLine() but just don't care if it's still there in memory awaiting for next line
23:17	grandy	justin_smith: ahh ok
23:18	justin_smith	zerkms: well, it checks if the thread is interrupted (future-cancel will do the thread-interruption for you)
23:18	zerkms	justin_smith: for the check to occurr a next line should arrive
23:19	justin_smith	right, polling is more complicated, but also possible
23:19	zerkms	ok
23:19	justin_smith	zerkms: like adding an if based on whether data is available, and a sleep if it isn't
23:19	justin_smith	then you are guaranteed to check the condition more often
23:20	zerkms	I'm not caviling (not sure if it's a correct word here, cannot find better in my dictionary) - just pretty newbie with clojure so want to make sure I'm not missing something basic
23:20	verma	justin_smith, nice! that seems to work great! thanks for your help
23:20	verma	(inc justin_smith)
23:20	lazybot	⇒ 120
23:20	justin_smith	zerkms: and you just need to look out for the pathological condition where there is data, but it freezes in the middle of giving you a line
23:20	justin_smith	verma: which one, the fixing lein run, or specifying the main class?
23:21	zerkms	honestly I tried implementing polling then realized the code looks like java
23:21	justin_smith	heh
23:21	justin_smith	there isn't much purely functional about a polling loop
23:22	zerkms	tried to reimplement simplified http://commons.apache.org/proper/commons-io/apidocs/src-html/org/apache/commons/io/input/Tailer.html which is I find nice implementation for this task (in java though)
23:22	verma	justin_smith, oh actually chestnut comes with a Procfile which had the exact same command :P
23:22	justin_smith	zerkms: there is java.nio.* too, I don't have a whole lot of experience with it though
23:23	justin_smith	verma: haha, nice
23:23	justin_smith	verma: so I could have just said rtfpf
23:23	verma	justin_smith, totally :P
23:24	zerkms	" java.nio.* too" --- yep, I deliberately want to do that as much manually as possible, as a person who only read A LOT and watched A LOT of different things about clojure but have written < 100 lines in total in clojure
23:24	justin_smith	grandy: small thing about your last paste, the comment about (:session session) isn't quite accurate, for what it's worth - you probably meant (:session params), but that's just a nitpick
23:25	justin_smith	zerkms: interop isn't super hard, and this is the sort of thing clojure just doesn't have a simple clojure-wrapped solution for
23:25	justin_smith	sorry
23:25	grandy	justin_smith: please do nitpick, this is my first clojure project so I need to be informed of any/all stupidity :)
23:25	zerkms	(inc justin_smith)
23:25	lazybot	⇒ 121
23:25	grandy	justin_smith: ok so now it works nearly as expected, with the following three handlers:
23:26	zerkms	would it ban me if I inc myself? :-D
23:26	grandy	https://www.irccloud.com/pastebin/X5Wu3LCN
23:26	justin_smith	it'll just be sassy about it
23:26	grandy	justin_smith: those map to /session /session1 and /session2
23:26	justin_smith	grandy: cool
23:27	justin_smith	grandy: what's handy for this kind of thing is update-in / assoc-in
23:27	grandy	justin_smith: hmm how woudl I modify those?
23:27	justin_smith	,(update-in {:session {:count 0}} [:session :count] inc)
23:27	clojurebot	{:session {:count 1}}
23:27	justin_smith	,(update-in {:session {:count 0}} [:session :count-2] (fnil inc 0))
23:27	clojurebot	{:session {:count-2 1, :count 0}}
23:28	justin_smith	grandy: update-in is pretty much perfectly designed for this kind of case (I intentionally burried :session deeper than needed to show how it digs in)
23:29	justin_smith	&clojure-version
23:29	lazybot	⇒ {:major 1, :minor 4, :incremental 0, :qualifier nil}
23:30	verma	TIL fnil
23:30	justin_smith	fnil is my friend
23:30	justin_smith	(inc fnil)
23:30	lazybot	⇒ 3
23:31	grandy	justin_smith: thanks!
23:31	justin_smith	grandy: np, glad you figured it out
23:36	zerkms	justin_smith: cannot get it working :-( (while ...) blocks while not finished which is never
23:37	justin_smith	zerkms: did you put it in a future?
23:37	zerkms	yep, and whern I'm dereferencing it - it blocks
23:37	zerkms	since `while` works forever
23:37	justin_smith	yeah, deref is not what you want
23:38	justin_smith	unless you want it to be done, and get the return value
23:38	justin_smith	futures run whether you deref them or not
23:38	zerkms	yep, but how to get the value from it then
23:38	zerkms	a global atom would be ugly
23:38	justin_smith	zerkms: you could send the values to an agent or queue
23:39	justin_smith	or act on the data within the loop itself
23:39	zerkms	or that... doesn't look idiomatic hmm
23:39	zerkms	I thought it will be trivial to implement an infinite list
23:39	zerkms	s/list/sequence/
23:39	Raynes	Well that's not great.
23:41	justin_smith	zerkms: hmm (defn f [handle] (when more-data (cons (read-available handle) (lazy-seq (f handle)))))
23:41	justin_smith	that's kind of like line-seq
23:41	justin_smith	maybe that's all you need? but line-seq will block too won't it?
23:41	zerkms	handle is the last resort for me, but yes
23:53	grandy	justin_smith: oddly it appears that it's not using the cookie params I am setting, it is also not using the name, therefore I think it is ignoring the configuration info for cookie sessions -- thoughts?
23:53	grandy	https://www.irccloud.com/pastebin/thNcygv4
23:56	justin_smith	that looks right