#clojure – 2013-10-15

2013-10-15

00:00	Raynes	&(doc some-fn)
00:00	lazybot	⇒ "([p] [p1 p2] [p1 p2 p3] [p1 p2 p3 & ps]); Takes a set of predicates and returns a function f that returns the first logical true value returned by one of its composing predicates against any of its arguments, else it returns logical false. Note that f is short-circu... https://www.refheap.com/19823
00:03	tsantos	Raynes: that sure looks like what I wanted. Testing it out...
00:07	tsantos	Raynes: yep, works like a charm, thanks.
00:31	yeoj___	jjkk/quit
01:03	dobry-den	(File. (clojure.java.io/resource "test.jpg")) ; Error, File doesn't know type URL.
01:04	dobry-den	(File. (.toURI (clojure.java.io/resource "test.jpg"))) ; Success
01:04	dobry-den	-__-
01:16	satshaba2	(:key value) vs (value :key) ------- Fight!
01:17	satshaba2	no really which is prefered?
01:22	SegFaultAX	If your keys are keywords, prefer using the keywords in function position.
01:23	Raynes	Whichever one looks best in context.
01:23	satshaba2	hmmmm
01:24	satshaba2	Well I come from python so I'm more inclined for (mapthing :key)
01:24	satshaba2	i.e. mapthing[key]
01:25	satshaba2	but it might make sense to do (:key mapthing) because then I think "key of mapthing"
01:26	SegFaultAX	To me (:kw foo) is pretty unambiguous in most situations. (foo :kw) could be a lookup or a normal function call.
01:27	satshaba2	ahh yes I see
01:27	satshaba2	ok then (:kw foo) it is!
01:28	SegFaultAX	satshaba2: Pick a style and stick with it, that's the most important thing.
01:28	satshaba2	yes agreed. I pick (:kw foo)
01:28	SegFaultAX	I just prefer to use (:kw foo) because it's more visually obvious that I'm doing a lookup.
01:28	SegFaultAX	Cool.
01:35	bitemyapp	SegFaultAX: I do the same thing.
01:35	bitemyapp	(:kw foo)
01:35	bitemyapp	SegFaultAX: the other reason to do it is that some map-like data structures will not implement IFn
01:35	bitemyapp	such as datomic entities.
01:36	bitemyapp	satshaba2: ^^
01:39	SegFaultAX	bitemyapp: Yup
02:30	logic_prog	is there a clojurescript cookbook ?
02:35	ered	i just started running through https://github.com/magomimmo/modern-cljs and i'm already impressed
02:35	jonasen	logic_prog: I don't think so
02:35	ered	speaking of clojurescript anyway
02:35	logic_prog	the pre-requisite for that page aone would take a year to read
02:36	ered	i'm only so far into this as idiomatic-for-javascript-but-just-ported-to-clojurescript (.getElementById js/document "email")
02:37	ered	and even just adding a repl that i can talk to my browser is still really cool
02:37	ered	can't wait to see what this looks like later on when it actually gets to idiomatic clojure
02:46	shoshin	hello, ping.
02:46	shoshin	i have a question that i've been trying to work through a bit.
02:47	shoshin	how do i access a value that is present inside a vector.
02:47	sm0ke	,([1 2 3] 1)
02:47	clojurebot	2
02:47	shoshin	[{:a 1 :b 2 :c 3} {:a 4 :b 5 :c 6}] i want to access the values of key :a
02:48	shoshin	sm0ke
02:48	shoshin	^^
02:48	sm0ke	,(map [{:a 1 :b 2 :c 3} {:a 4 :b 5 :c 6}] :a)
02:48	clojurebot	#<IllegalArgumentException java.lang.IllegalArgumentException: Don't know how to create ISeq from: clojure.lang.Keyword>
02:48	sm0ke	oops wait
02:48	sm0ke	,(map :a [{:a 1 :b 2 :c 3} {:a 4 :b 5 :c 6}])
02:48	clojurebot	(1 4)
02:48	sm0ke	hehe i am still learning too
02:49	shoshin	sm0ke thank you! I need to dig more into map and clojure's data structures.
02:49	shoshin	any resources/pointers?
02:49	sm0ke	shoshin: the vector which you gave has each element as a map
02:50	sm0ke	shadower: now keyword also act as fucntions on maps like ##(:key {:key :value})
02:50	lazybot	⇒ :value
02:50	sm0ke	finally the (map) function runs the function passed as first argument on each element of collection and returns the new collection
02:51	sm0ke	oops he left
02:56	sm0ke	hey guys in my project.clj i have defined a :main namespace and also a profile {:package {:aot :all}} ,, but when i gnerate a uberjar using 'lien with-profile uberjar'and try to run with 'java -cp my.jar main.name_space' ,,i get 'could not find or load main class main.name_space'
02:56	sm0ke	also i see that namespace being compiled while generating uberjar
03:01	sm0ke	i workaround this by putting (:gen-class) in my main namespace..but i dont know if this is the correct way
03:01	terom	you will need :gen-class for AOT, so it is not a workaround, but requirement, afaik
03:03	sm0ke	i really dont understand what compilation mean in leinigen
03:03	llasram	You don't need :gen-class for AOT, but you do need :gen-class for AOT to produce an actual class for the namespace
03:03	sm0ke	is compiling and generating class different?
03:03	llasram	Yes
03:04	sm0ke	really?
03:04	llasram	So on the JVM you do need an actual class to hold bytecode for any functions as method
03:04	sm0ke	isnt compilation means generating class on jvm?
03:04	llasram	The way Clojure does that is by having a class per function
03:05	llasram	So doing AOT will pre-generate the classes for all of your functions
03:05	sm0ke	but not my namespace?
03:05	llasram	Exactly. You only get a class for a namespace with e.g. your static main by specifying that that namespace should :gen-class
03:06	llasram	That said, you don't need to AOT and :gen-class to get an entry-point, or really even an uberjar entrypoint, even if you really need that
03:06	llasram	My preferred approach is to use the `clojure.main` class included in Clojure
03:06	sm0ke	hmm didnt know about that
03:06	llasram	then you can do: java -cp my-uberjar.jar clojure.main -m my.name.space
03:07	llasram	And that will run the `-main` method in my.name.space
03:07	sm0ke	oh i see
03:08	sm0ke	llasram: worked like a charm thanks!
03:08	sm0ke	i guess using that approach we can have multiple main methods too
03:08	sm0ke	in deifferent namespaces though
03:10	llasram	You can also call `clojure.main` with `-e <string>` to `eval` some arbitrary string
03:12	Jarda	if I have a dependency from clojars that is causing me trouble, how can I install it locally to get possibility to fix it
03:13	Jarda	I mean, is there a way of doing git-dependencies or such with leiningen2
03:13	terom	llasram: Hmm. I usually produce uberjars so that I can java -jar my-uber.jar, but that didn't occur to my mind that I could then also do that. Seems logical though, now that I think more of that.
03:13	ered	Jarda: try lein-localrepo?
03:13	ered	https://github.com/kumarshantanu/lein-localrepo
03:14	ered	there might be something better than that
03:14	llasram	Jarda: If the project is using lein already, you don't need a plugin. Just checkout and `lein install`
03:14	llasram	(w/in the project)
03:14	ered	oh that's easier than mine :D
03:15	Jarda	llasram: so if my project is in ~/projects/myproject, where should I checkout the dependency?
03:15	Jarda	oh, or do you mean it can be wherever and leiningen will just know where to fetch the dependency
03:15	llasram	Oh, well
03:16	llasram	So if you `lein install` it'll install the version that project's project.clj declares it to be; i.e., probably some SNAPSHOT release
03:16	llasram	If you just want to pull the dep in as source in your project, that's what "checkout" dependencies are for
03:17	llasram	Check the second project out wherever you like, then
03:17	llasram	in your project create a directory called "checkouts", and w/in that dir make a symlink for the dependency named for the dependency artifact basename
03:18	llasram	Just linking to the dependency project top-level directory
03:18	llasram	The lein doco has more details
03:19	Jarda	https://github.com/technomancy/leiningen/blob/master/doc/TUTORIAL.md#checkout-dependencies ?
03:19	Jarda	thanks :)
03:19	ered	llasram: neat, i'll have to remember that one
03:19	llasram	terom: Yeah. I used them when I first started doing Clojure, but at this point I'm actually not entirely certain what uberjar main functions are really for. I always need e.g. a wrapper shell script anyway
03:19	llasram	Jarda: yep, and np!
03:19	sm0ke	i think the only problem is when the external project installs on ivy
03:19	ered	i have a few things i'm going to be working on soon where i'll be working on a project, but also a couple supporting libraries, in parallel
03:19	sm0ke	lein cant fetch from local ivy repos
03:20	llasram	Yeah, if the external dep doesn't use lein, then you need to e.g. use `mvn` (or maybe lein-localrepo -- haven't used) to make it available locally
03:20	sm0ke	but who uses ivy anyways..
03:21	sm0ke	no one uses scala from clojure is guess
03:21	llasram	At least not directly much thus-far
03:22	terom	llasram: true, I seem to find that also. In some rare cases I just want to run uberjar as-is. I guess if I have some GUI application it makes more sense. (On Windows, I can then just double-click the .jar to launch it)
03:23	sm0ke	i think clojure interop with scala will be nasty..specially with Scala people using case classes almost everywhere
03:23	sm0ke	i dont know how well clojure treats case classes
03:24	llasram	terom: Yeah, that may be true. Although the one time I've needed that so far, I used the `lein-exec` approach of embedding a prefix combo sh/.bat script at the beginning of the file
03:24	sm0ke	also one more with with that clojure.main approach.. i had to replace underscore with hyphen
03:24	sm0ke	dont know what thats all about
03:25	llasram	sm0ke: Does your namespace have an '_' in it?
03:25	sm0ke	yes
03:25	llasram	Interesting
03:25	llasram	&(map munge ["some-name" "same_name"])
03:25	lazybot	⇒ ("some_name" "same_name")
03:26	llasram	Clojure name munging for JVM representation isn't reversible
03:26	llasram	And since "-" is munged to "_"
03:26	llasram	using "_" kind of humorously can get you into trouble sometimes
03:26	llasram	Best to just stick w/ convention and use "-" :-)
03:27	sm0ke	llasram: no no wait i think you misunderstood
03:27	llasram	TOO LATE
03:27	sm0ke	llasram: i have _ in my namespace's parent folder name
03:27	sm0ke	like org_some/namespace
03:28	sm0ke	inside clojure file i write it as org-some.namespace
03:28	sm0ke	i think thats the convention in clojure
03:28	llasram	Oh, ok, yeah. So the actual name of the namespace is "org-some.namespace", which is in fact what you need to pass to clojure.main
03:30	sm0ke	llasram: yes but if you put (:gen-class) in yu ns and invoke it deirectly via java -jar you have to put _ in main ns
03:30	llasram	sm0ke: Right -- because then you're directly feeding the munged JVM name to the `java` command
03:31	sm0ke	hmm ok weird enough.. i am just wondering why didnt i make a folder by name 'org-some' in the first place then
03:33	sm0ke	aha .. http://stackoverflow.com/questions/4420944/why-does-clojure-convert-dashes-in-names-to-underscores-in-the-filesystem/4451693#4451693
03:34	sm0ke	so much for java interop
03:34	llasram	Yeah, that's the ultimate reason. And for directories is just simpler -- otherwise your build tool would need to munge each directory name when adding stuff to the JAR, which has a lot of confusion-potential
03:34	llasram	Especially for e.g. resources
03:36	sm0ke	yeah makes sense
03:37	sm0ke	but i really was hoping clojure.main would automatically convert between _ and - by itself for its argument
03:38	sm0ke	anyhoo its trivial to nag for
03:38	llasram	Eh. It explicitly takes the Clojure namespace name. You can't in Clojure (:require 'org_some.namespace)
03:39	sm0ke	got it!
03:54	glosoli	How does one define snippet in Enlive with optional arguments ?
04:02	muhoo	why (-> (foo "bar") baz quuz) not (-> "bar" foo baz quuz) ? i see that pattern and wonder why
04:03	llasram	muhoo: Starting with (foo "bar"), adding the -> and not thinking about it is my guess :-)
04:03	llasram	I did see someone once here claim that they found e.g. (-> "some-path" io/file .exists) confusing though
04:09	muhoo	it is kind of rpn-ish i guess
04:09	muhoo	in datomic it's common to have (->> (d/q '[massive bunch of stuff ]) foo bar baz) though
04:10	llasram	Huh
04:10	llasram	Interesting
04:11	muhoo	but if there's just one arg to that first function, i don't see why not just thread it in with everything else
04:11	llasram	Yeah, I'm with you there
05:06	talios	'lo cemerick
05:08	cemerick	talios: Hi Mark :-)
05:09	talios	using pristmatic schema of course, gotta have my types!
05:10	dcunit3d	where do u work lol
05:10	glosoli	dcunit3d: lol, we find it easier to collect and manager your data with Clojure :D
05:10	glosoli	at NSA :DD
05:10	dcunit3d	lol
05:10	talios	dcunit3d: http://www.smxemail.com - move to New Zealand and work for us ;)
05:11	glosoli	dcunit3d: Small company in Europe Lithuania :) you wouldn't know ;d
05:11	glosoli	Still kinda fun though
05:11	talios	tho currently we're desperate for some coffeescript/javascript skilz
05:11	cemerick	talios: good deal. No typed clojure tho?
05:11	dcunit3d	new zealand sounds fun. anywhere with good mountains sounds fun
05:12	dcunit3d	i'm currently in boulder, but haven't found much clojure here yet
05:12	talios	cemerick: looking at it :) we have ambrose on the podcast again last week, I see schema plans to maybe also compile out core.typed annotations which could be good
05:12	dcunit3d	colorado
05:12	cemerick	dcunit3d: talios uses osgi voluntarily. Serious warning sign, right? ;-P
05:12	cemerick	talios: yup, I heard, enjoyed it :-)
05:12	talios	lolz, if we could drop it we would. Altho, I'd rather keep OSGi and dump hibernate first :)(
05:13	talios	cemerick: had to do some 'creative' editing with the intro to ambrose as we wern't sure if he was showing up or not, then turned up in the middle of recording ;0
05:14	talios	cemerick: i'm missing your show - record!!!
05:14	glosoli	what kind of show ?
05:15	cemerick	talios: yeah, I know. It's been tough to squeeze it in of late. :-(
05:16	talios	glosoli: cemerick's clojure podcast, and my "generic software development maven build love/hate scala/clojure/frege" podcast
05:16	glosoli	talios: where??
05:16	lazybot	glosoli: Definitely not.
05:16	llasram	Is lazybot a bit spastic???
05:16	lazybot	llasram: Oh, absolutely.
05:17	talios	glosoli: http://www.illegalargument.com/ is mine, latest show has Ambrose on talking about core.typed ( his 2nd appearance )
05:17	cemerick	glosoli: http://mostlylazy.com
05:17	talios	cemerick himself is mostly lazy, so hasn't recording in a LONG time.
05:17	glosoli	Damn guys, thanks! :)
05:18	cemerick	talios: that was an intentional reference :-)
05:18	cemerick	I didn't want people to think it'd be a regular thing...but I didn't mean for it to be quarterly, either.
05:18	talios	glosoli: I think the two interviews with Ambrose, and the one we did with James Ladd on Redline Smalltalk are our most listened to shows ( and most enjoyable to record )
05:19	glosoli	talios: I never heard of them... (a bit out of date here) will have to catch up today! :)
05:19	talios	cemerick: could you worse, you could have been like arbscht and started "The Weekly REPL" podcast, do 4 episodes and stop :)
05:19	cemerick	hah, yeah
05:21	talios	for awhile, we considered getting arbscht on our show regularly, but then we'd have 3 cohosts all at the same company :)
05:21	talios	and I think theres only so many ways we can mangle the company name
05:23	talios	anyone tried out Cursive here? Been using the EAP all week and it's so much better than La Clojure from Jetbrains
05:24	glosoli	talios: is it truth that cursive will become commercial at some poitn ?
05:24	glosoli	point"
05:25	talios	glosoli: that's colins aim yes, I believe Jetbrains are also going to seed the clojure space to Cursive so as to not compete
05:26	sm0ke	is anyone working with light table too?
05:26	glosoli	talios: Kinda makes me want to stay way from it, until I learn about the pricing
05:26	talios	La Clojure was never really had anyone full time on it anyway
05:27	glosoli	Yeah :) just because of Clojure I got used to Emacs, and even used tried vim lol
05:28	talios	glosoli: I'll chase up Colin on pricing ( he's supposed to be hotdesking next to me for the next week or so ), I think he wants it to be cheap, comparable in pricing to some of the cheapers JB offerings I think
05:28	sm0ke	vim does pretty good with clojure
05:29	talios	I've dabbled with emacs for the last 20 odd years, and I still can't grapple the archaic key cording
05:30	glosoli	Dunno it kinda felt easy for me (though I hadn't used it more than half year)
05:40	Jarda	is anyone aware of a clojurescript core.async wrapper for making xhr requests?
05:47	sm0ke	that would be cool
05:48	Jarda	http://dimagog.github.io/blog/clojure/clojurescript/2013/07/12/making-http-requests-from-clojurescript-with-core.async/
05:48	sm0ke	i think there are some old libraries which wrap jQuery..like jayq
05:48	Jarda	this is cool, but I'm looking more like a complete library to use
05:48	sm0ke	it wont be hard to put that in a core.async channel goroutive
05:49	Jarda	sm0ke: yeah that blog post shows just that (using goog.net XHR)
05:49	Jarda	but I don't feel like wrapping callback code by myself
05:51	sm0ke	Jarda: hmm well i dont know what clojure experts have to say about it..but core.async just need the most minimal changes...its pretty un intrusive way of introducing async behaviour
05:52	sm0ke	coming from scala and working with actors i dont mind put a feww go blocks and >! !<
05:53	sm0ke	let me know if you find one
05:53	sm0ke	:P
07:02	glosoli	Enlive question here, I have map consisting of key that stands as element id, and value as error message, any suggestions how could iterate the keys and at the same time be doing selection of these elements, so I could add classes to them ?
07:05	notofi	hi. Why does this code declare 'x' ?
07:06	clgv	glosoli: since you want to do side effects you can use (doseq [[k v] mymap] (do-somthing k, v))
07:06	notofi	(defn testfn [] (def x 1))
07:07	clgv	notofi: do not use `def` in functions - `def` is only intended for definition of symbols in a namespace and not for "local variables" (= local bindings)
07:07	clgv	notofi: you want `let`, e.g. (defn testfn [] (let [x 1] (+ x 2)))
07:07	glosoli	clgv: hmm now when I thought, all I need to do set same class on several nodes hmm there should be something inbuilt I am not aware of
07:08	notofi	clgv: I know I shouldn't do this but I am working with some code that uses for example defonce in some init functions. Before that there is a declare, and as I see it this declare is not needed
07:08	clgv	glosoli: oh you actually search for a way to select all nodes with keys in the map at once?
07:09	clgv	notofi: this non idiomatic and probably leads you straight to hell sooner or later ;)
07:09	glosoli	clgv: I have a list of keywords (which would correspond to the right ids in html template) and I want to select all them at once and apply some action like add-class
07:10	clgv	notofi: if you really need to set a value to a variable in a namespace from an init function better define the var with defonce and an atom a value and swap the atom in the init function
07:11	notofi	clgv: why you shouldn't do this? it seems shorter than using an atom
07:11	clgv	glosoli: I dont know whether there is a built-in helper for that. since an id should be unique I guess this is not considered basic functionality
07:12	glosoli	clgv: Ids are unique
07:12	glosoli	I have a list of ids, I wanna do the selection of them and execute add-class on all of them
07:12	clgv	glosoli: yes thats what I said ;)
07:12	glosoli	aa ok
07:13	clgv	glosoli: you could simply use `map`+ the id selection function
07:18	glosoli	clgv thanks
07:20	clgv	notofi: you can read that up on the mailinglist. the discussion is often repeated.
07:21	clgv	notofi: my personal reason is that it will be hard to understand and reason about your code if you use `def` within functions regularly
07:22	clgv	notofi: there are better more technical reasons to avoid it
07:28	notofi	clgv: you know any? :)
07:29	glosoli	clgv: In case you are curious, that's easily doable by grouping your selectors in set
07:29	clgv	glosoli: you mean you can use enlive's `select` with a set of ids?
07:31	glosoli	more like [#{:#some_id :#some_other_id}] (add-class "error")
07:31	glosoli	I guess it applies select on it, though I don't use select directly
07:34	clgv	ah ok. I only know enlive's `select` from seesaw ;)
08:17	augustl	json sucks.. I want most keys to be keywords in maps after json parsing, but some keys are numbers, and I want those to be numbers, not symbolized numbers, i.e. :0. But in JSON, all keys are strings. Meh!</rant>
08:21	shoshin	ping
08:21	shoshin	i have a question, give an sequence containing maps how would i try to find if a particular key is present in any of the maps or not?
08:22	shoshin	for example ({:a 1 :b 2 :c 3} {:a 4 :b 5 :c 6} {:a 7 :b 8 :c 9})
08:22	shoshin	how do i find if the key :a is present in all the maps?
08:22	sm0ke_	augustl: i think if prsing using cheshire you can opt for keywods as keys (parse-string "{\"foo\":\"bar\"}" true)
08:23	rkneufeld	shoshin: probably via some
08:23	sm0ke_	the true flag towards the end
08:23	shoshin	rkneufeld would some work on a sequence?
08:23	rkneufeld	shoshin: I think so, give it a go in a REPL.
08:23	augustl	sm0ke_: teah that's what I do, but then the JSON {"0":"test","5":"bar"} will become {:0 "test" :5 "bar"}, since json sucks :)
08:24	sm0ke_	augustl: so what do you want instead?
08:25	shoshin	rkneufeld i tried the following (some #{:a} ({:a 1 :b 2 :c 3} {:a 4 :b 5 :c 6})
08:25	shoshin	returns nil
08:26	rkneufeld	The list of maps you have isn't quoted
08:26	augustl	sm0ke_: I want to be able to tell the world that the keys are numbers, not strings, which json doesn't support
08:26	Morgawr	`(let [a {:a :b :c :d}] (str (map reverse (into [] a))))
08:26	rkneufeld	shoshin: It's trying to find the first map inside the second (or the other way around…). Add a single quote in front of ({:a 1 ...)
08:27	Morgawr	how do I trigger clojurebot? D:
08:27	sm0ke_	augustl: are you sure?
08:27	sm0ke_	var a = {3: 4} on my browser repl works fine
08:27	augustl	sm0ke_: yeah, keys have to be strings. Or, you could of course parse the string and check if it only contains ascii number characters
08:27	sm0ke_	a[3] also returns 4
08:27	augustl	sm0ke_: JS will stringify that automatically actually
08:27	augustl	sm0ke_: and JS != JSON anyway :)
08:27	rkneufeld	shoshin: hmm, that doesn't work either. Must be something off about the set. It works with :a alone.
08:27	shoshin	rkneufeld (some #{:a} '({:a 1 :b 2 :c 3} {:a 4 :b 5 :c 6}))
08:28	sm0ke_	isnt json = javascript object notation?
08:28	shoshin	doesn't work, yes.
08:28	Morgawr	&(let [a {:a :b :c :d}] (str (map reverse (into [] a))))
08:28	lazybot	⇒ "clojure.lang.LazySeq@bc3043e0"
08:28	Morgawr	how do I make it not print LazySeq? ^
08:28	Morgawr	I tried using doall but it doesn't work
08:28	rkneufeld	&(some #a '({:a 1 :b 2 :c 3} {:a 4 :b 5 :c 6})
08:28	lazybot	java.lang.RuntimeException: No reader function for tag a
08:28	rkneufeld	&(some a '({:a 1 :b 2 :c 3} {:a 4 :b 5 :c 6})
08:28	lazybot	java.lang.RuntimeException: EOF while reading, starting at line 1
08:28	sm0ke_	anyways i am not sure if i understand
08:28	rkneufeld	&(some a '({:a 1 :b 2 :c 3} {:a 4 :b 5 :c 6}))
08:28	lazybot	java.lang.RuntimeException: Unable to resolve symbol: a in this context
08:28	rkneufeld	&(some :a '({:a 1 :b 2 :c 3} {:a 4 :b 5 :c 6}))
08:28	lazybot	⇒ 1
08:28	Morgawr	&(let [a {:a :b :c :d}] (str (doll (map reverse (into [] a)))))
08:28	lazybot	java.lang.RuntimeException: Unable to resolve symbol: doll in this context
08:28	augustl	sm0ke_: not entirely, {foo: "bar"} is invalid JSON
08:28	Morgawr	&(let [a {:a :b :c :d}] (str (doall (map reverse (into [] a)))))
08:28	lazybot	⇒ "clojure.lang.LazySeq@bc3043e0"
08:28	Morgawr	:\|
08:29	augustl	sm0ke_: it has to be {"foo":"bar"} (quote the key)
08:29	rkneufeld	shoshin: the last one (typing is hard)
08:29	sm0ke_	augustl: what the...yes of course...its invalid everywhere
08:30	shoshin	rkneufeld you mean this one? (some :a '({:a 1 :b 2 :c 3} {:a 4 :b 5 :c 6}))
08:30	sm0ke_	without foo being defined
08:30	augustl	sm0ke_: considering adding content type negotiation so I can serve EDN which has sets and arbitrary map keys and what not
08:30	sm0ke_	,{foo :bar}
08:30	clojurebot	#<CompilerException java.lang.RuntimeException: Unable to resolve symbol: foo in this context, compiling:(NO_SOURCE_PATH:0:0)>
08:30	sm0ke_	,{'foo :bar}
08:30	clojurebot	{foo :bar}
08:30	shoshin	rkneufeld i think i need to map the some over the collection.
08:30	jonasen_	&(let [a {:a :b :c :d}] (pr-str (map reverse (into [] a))))
08:30	lazybot	⇒ "((:b :a) (:d :c))"
08:30	shoshin	*sequence
08:31	jonasen_	Morgawr: ^
08:31	Morgawr	jonasen_: okay but that is only if I want to use "str" on it, how do I make sure it realizes anyways?
08:31	Morgawr	I thought doall would realize sequences
08:32	rkneufeld	shoshin: yeah. Check out https://github.com/clojure-cookbook/clojure-cookbook/blob/master/composite-data/determining-if-a-collection-holds-one-of-several-values/determining-if-a-collection-holds-one-of-several-values.asciidoc – some applies the set to each value of the seq. (#{:a} {:a 1}) is nil, but (#{:a} :a) is :a.
08:32	sm0ke_	well json is a subset of clojure maps...so yes that would not work both ways
08:32	sm0ke_	js has no concept of sets
08:33	shoshin	rkneufeld that helped me understand this! Thank you so much!
08:33	jonasen_	&(let [a {:a :b :c :d}] (str (seq (map reverse (into [] a)))))
08:33	lazybot	⇒ "((:b :a) (:d :c))"
08:33	augustl	sm0ke_: indeed, and some times I want to convey that something is a set, not a sorted list
08:33	wakeup	Hi all
08:34	wakeup	I get a IllegalStateException I/O in transaction
08:34	sm0ke_	augustl: may be you want to cosider serialization instead?
08:34	wakeup	I guess it's because I do a database write during dosync
08:34	jonasen_	Morgawr: Use seq
08:34	wakeup	How do I solve this without using a lock?
08:35	sm0ke_	augustl: something like nippy?
08:36	Morgawr	jonasen_: alright, thanks
08:37	wakeup	AH solved it
08:37	augustl	sm0ke_: or EDN :)
08:38	augustl	and content negotiation where the client says which content types it accepts, HTTP style
09:21	clgv	wakeup: if you want to do sequential I/O from transactions agents fit pretty well for that
09:22	tbaldridge	wakeup: a little more context may help as well. What is the lock doing?
09:49	rurumate	woohoo from euroclojure
09:50	rurumate	they finally got the wlan running
09:51	mdrogalis	:)
09:51	ssideris1	hey! I'm there (here) too
09:51	ambrosebs	hello euroclojure!
09:52	mdrogalis	What city is it in?
09:52	rurumate	berlin
09:53	mdrogalis	Sounds terrific
09:53	rurumate	why is everyone saying haitch-tml today, pronouncing the letter H this way? is this a new fancy way to speak?
09:54	ssideris1	rurumate: I think it's a british thing
09:55	rurumate	apparently not everyone agrees on that: http://www.youtube.com/watch?v=c3y0CD2CoCs
09:57	dobry-den	tbaldridge: That was a good macro vid
10:00	mdrogalis	dobry-den: Yeah I learned a lot from that screencast.
10:00	mdrogalis	If it's the one I think you're talking about, heh.
10:08	tbaldridge	dobry-den: great! I'm glad it helped
10:09	silasdavis	I've currently got some code that uses the AmazonS3Client directly and I was considering the merits of using: https://github.com/weavejester/clj-aws-s3/blob/master/src/aws/sdk/s3.clj
10:09	silasdavis	but it looks like that doesn't allow you to create an s3-client with the parameter-less constructor
10:11	silasdavis	Currently I am using the parameter-less constructor and an instance profile on elastic beanstalk which has s3 credentials attached which the S3 client knows how to find if given no creds
10:12	silasdavis	shall I just stick with the java SDK?
10:12	tbaldridge	silasdavis: I find little reasons not to use bare Java APIs for most things
10:12	tbaldridge	many wrapper libraries don't add much in the way of clojure integration, and simply restrict your options.
10:13	silasdavis	great, that was the sort of validation I was after, I use the bare api, seems nice enough anyway
10:44	wakeup	(seq (take ....)) is not lazy or is it?
10:44	llasram	wakeup: Why would it not be lazy?
10:44	tbaldridge	wakeup: it's lazy
10:44	wakeup	do I need to use doall?
10:45	llasram	Not if you want it to be lazy :-)
10:45	tbaldridge	wakeup: yep, or do vec on it. I often prefer to make all my non-lazy seqs into vectors.
10:45	wakeup	is pmap lazy?
10:45	tbaldridge	wakeup: yep
10:46	wakeup	ok
10:46	Morgawr	it's semi-lazy :P
10:46	tbaldridge	wakeup: if it deals with seqs, it's lazy. Unless specified otherwise.
10:46	Morgawr	&(doc pmap)
10:46	lazybot	java.lang.SecurityException: You tripped the alarm! pmap is bad!
10:46	Morgawr	:\|
10:46	Morgawr	dang lazybot
10:46	tbaldridge	,(doc pmap)
10:46	clojurebot	"([f coll] [f coll & colls]); Like map, except f is applied in parallel. Semi-lazy in that the parallel computation stays ahead of the consumption, but doesn't realize the entire result unless required. Only useful for computationally intensive functions where the time of f dominates the coordination overhead."
10:46	tbaldridge	:-P
10:46	Morgawr	thanks :P
10:47	wakeup	,(doc doall)
10:47	clojurebot	"([coll] [n coll]); When lazy sequences are produced via functions that have side effects, any effects other than those needed to produce the first element in the seq do not occur until the seq is consumed. doall can be used to force any effects. Walks through the successive nexts of the seq, retains the head and returns it, thus causing the entire seq to reside in memory at one time."
10:47	tbaldridge	&(let [pmap 42] 42)
10:47	lazybot	java.lang.SecurityException: You tripped the alarm! pmap is bad!
10:47	tbaldridge	lol
10:47	mdrogalis	Bad tbaldridge D:
10:47	Morgawr	time to report to the authorities
10:47	Morgawr	keep calm and don't panic
10:47	mdrogalis	Get this guy outta here, he's using pmap. D:
10:48	tbaldridge	I like to live dangerously
10:52	wakeup	What about ref's, I seem to be unable to predict their value,
10:52	wakeup	anything I should know about using deref?
10:52	mdrogalis	wakeup: Predict?
10:57	tbaldridge	wakeup: I agree with mdrogalis I don't understand the word "predict" in this context.
10:57	mdrogalis	(crystal-ball IRef)
10:57	mdrogalis	Backed by data.generators 'anything' function :)
11:16	sm0ke	is the quick sort example in joy of clojure the worst example ever or what?
11:16	sm0ke	i remember reading a quicksort in lyah
11:16	sm0ke	clojure version is hedious
11:17	benmoss	whats bad about it
11:18	llasram	sm0ke: If the version of quicksort in LYAH is pretty, I'm willing to bet that it isn't really a quicksort
11:19	sm0ke	http://learnyouahaskell.com/recursion ... its pretty neat
11:20	llasram	Actually, now that I'm looking at them, neither one is actually quicksort
11:21	wakeup	NullPointerException clojure.core/fn--5420 (core_print.clj:187)
11:21	wakeup	I can't see em any more...
11:22	indigo	wakeup: :P
11:22	indigo	I like your nick, btw
11:22	indigo	Helps me wake up in the morning xP
11:22	wakeup	I am serious though
11:23	wakeup	how am I supposed to debug my concurrent shit if I get NPE's from
11:23	wakeup	core_print ?
11:23	tbaldridge	wakeup: code paste?
11:24	dnolen	sm0ke: you can write a very nearly that neat in Clojure
11:24	dnolen	s/very/version
11:26	wakeup	tbaldridge: having trouble locating where the exception comes from.
11:26	wakeup	no stack trace either.
11:26	tbaldridge	https://github.com/clojure/clojure/blob/master/src/clj/clojure/core_print.clj#L187
11:26	wakeup	might as well segfault.
11:26	tbaldridge	even print-stack-trace on *e gives you nothing?
11:30	llasram	sm0ke: ##((fn qsort [[x & xs]] (if x (let [smaller? (partial >= x)] (concat (->> xs (filter smaller?) qsort) [x] (->> xs (remove smaller?) qsort))))) (repeatedly 20 (partial rand-int 256)))
11:30	lazybot	⇒ (0 17 27 29 46 64 74 113 119 121 126 145 171 174 184 185 194 197 206 245)
11:30	llasram	sm0ke: The version in /JoC/ is lazy, which takes a bit more work
11:37	zerokarmaleft	sm0ke: the beauty of the lazy JoC version is that if you select into the sorted result (with nth or drop & take, etc.), the algorithm only sorts the partitions necessary to give you the correct result
11:38	sm0ke	i guess..its beyond me..i am still a beginer
11:39	sm0ke	but still the structure of loop is bit confusing .. specially the recur call is hard to understand
11:40	sm0ke	list* with 4 arguments..crazy
11:50	indigo	Quick question
11:50	indigo	There is some fizzbuzz code on rosettacode written in Clojure
11:50	indigo	https://www.refheap.com/19834 <-- do you really need a lazy-seq considering there's already an iterate there?
11:51	Morgawr	mm. considering map is lazy, I'd say you don't need the lazy-seq but I'm not 100% sure
11:51	mdrogalis	I believe you can forego it.
11:52	indigo	It works if I forego it, but I'm just wondering if there is a reason that it was there
11:52	Morgawr	indigo: overengineering probably :P
11:53	indigo	Morgawr: Heh yeah, maybe I'll go ahead and update it on Rosetta Code
11:53	indigo	Concise code ftw
11:54	mdrogalis	Speaking of Fizz Buzz https://gist.github.com/MichaelDrogalis/4684403
11:54	mdrogalis	This is still hilarious to me.
11:55	stuartsierra	heh
11:55	glosoli	lol
11:55	zerokarmaleft	mdrogalis: haha
11:56	indigo	Heh
11:56	indigo	Too bad he didn't put the numbers in
11:57	mdrogalis	indigo: Yeah I think I got close enough and enjoyed that answer a lot, so I stopped. :P
11:57	si14	is there anyone who use Prismatic's Schema with CLJS?
11:58	si14	got my build suddenly broken, just a ton of "Use of undeclared Var [record-name-here]"
11:58	indigo	If anyone I interview writes FizzBuzz in Clojure, they're getting hired on the spot :P
11:59	mdrogalis	indigo: Even with my non-modulus magic?
12:00	indigo	Yep :P
12:01	indigo	Then I can have a buddy to complain about PHP with
12:01	wakeup	Now what could that hint to? java.util.concurrent.ExecutionException: java.lang.NullPointerException
12:01	wakeup	at java.util.concurrent.FutureTask$Sync.innerGet
12:02	marcopolo2	indigo: I used to work at a php shop, I feel your pain
12:02	indigo	Hehe
12:04	dgrnbrg	Is there a way in compojure or another accepted library for mounting a ring handler at a context path?
12:04	jonasen_	si14: did you update cljs?
12:04	si14	jonasen_: yes. -1934 now
12:05	clojurebot	Huh?
12:05	jonasen_	si14: did you run lein cljsbuild clean?
12:05	si14	jonasen_: yes
12:06	jonasen_	si14: do any of the warnings point to a particular file/line-number?
12:07	si14	jonasen_: yes. it looks like this: https://gist.github.com/si14/d7e5254391cffc2c51f7
12:07	si14	jonasen_: but for all records, actually
12:09	indigo	I think I killed RosettaCode :<
12:09	indigo	Oh no, nvm, it's back up again
12:10	noncom	if i have (defn hey [x] (+ 1 x)), how do i pass "hey" to a macro so that it gets passed not as 'hey, but as the form itself? or at least as the generated IFn object?
12:11	llasram	noncom: You don't
12:11	si14	jonasen_: when I run generated stuff in browser I get "Uncaught TypeError: Cannot set property 'schema$utils$schema' of undefined "
12:11	mdrogalis	New talk by Rich up on InfoQ :)
12:12	noncom	llasram: oh sad..
12:12	llasram	noncom: Why? You really don't need that
12:12	noncom	wait i make a simple example, maybe you can give a hint
12:13	llasram	ok
12:14	marcopolo2	mdrogalis: link?
12:17	mdrogalis	marcopolo2: http://www.infoq.com/presentations/datomic-functional-database?utm_source=infoq&utm_medium=videos_homepage&utm_campaign=videos_row3
12:17	marcopolo2	mdrogalis: thanks!
12:17	Creap	I have a plugin system, and a user can put a plugin in a directory and a namespace string in a config file. I then want to require the ns and get a function with a predefined name
12:18	Creap	(map (comp require symbol #(str % "/message-handler") :ns) (vals plugins)) is my current attempt, which doesn't work very well..
12:18	wakeup	What the hell. What could go wrong, so that locking doesn't work?
12:19	wakeup	When I comment out the actual (non-logging) body of locking it works fine
12:19	wakeup	when I do IO in the body, the lock is just ignored
12:19	mdrogalis	Sure!
12:19	wakeup	except logging
12:19	jonasen_	si14: I can reproduce.. I'll take a look if I can find the cause
12:19	wakeup	weeeiird i hate my job right now
12:19	si14	jonasen_: thank you very much.
12:20	tbaldridge	wakeup: you really have to give some context. ranting doesn't help if we don't even know what your problem is
12:20	wakeup	I don't either
12:21	wakeup	I am trying to produce a minimal example ;)
12:22	marcopolo2	Creap: are you requiring ns/func, instead of just the namespace?
12:24	Creap	in the example above yes, I've tried a number of variants though
12:25	marcopolo2	Creap: try not including the /func, just the ns, so get rid of the #(str ...)
12:28	Creap	marcopolo2: ok, but just to be clear, will require return the namespace, or just include the file?
12:28	Creap	if it does the latter, I think I have it working, but I expected a result as well
12:28	TimMc	wakeup: Laziness.
12:29	marcopolo2	Creap: pretty sure it will return nil
12:30	dobry-den	Question: Does loop/recur only exist because of the JVM's limitation?
12:30	dobry-den	I guess, what's the surrogate for loop/recur if you didn't have it?
12:30	TimMc	Yes, otherwise we'd just tail-call.
12:31	Creap	it did indeed, and they were required.. thanks, just need to get the message-handler for those namespaces now
12:31	noncom	llasram: sorry for the delay https://www.refheap.com/19835
12:31	dobry-den	TimMc: What's an example of how you'd write (loop [x 0] (when (< x 10) (recur (inc x))))
12:31	dobry-den	in other lisps
12:33	mdrogalis	lol Rich in that talk "What happens when you play with machines? You get hurt!"
12:34	llasram	noncom: I'm sorry, but I really don't have any idea what you're trying to do :-/
12:35	arrdem	mdrogalis: which one?
12:37	noncom	llasram: here is something like i do: http://blog.zololabs.com/2009/12/10/frumios-a-silly-object-system-for-clojure/ what if, in terms of that example, i want to use functions defined elsewhere as (method) instead of defining it in place?
12:37	mdrogalis	arrdem: The Functional Database. Find it on InfoQ. Very new.
12:38	marcopolo2	Creap: you could try (kinda hacky): (eval `(var ~(symbol "ns" "fn"))) => returns reference to ns/fn function
12:38	TimMc	dobry-den: (fn foo [x] (when (< x 10) (foo (inc x))))
12:38	marcopolo2	Creap: there has to be a better way to do that
12:38	dobry-den	TimMc: Does loop/recur only exist because it does something different than your example?
12:38	marcopolo2	Creap: don't do what I did
12:39	dobry-den	Clojure is my first lisp and in my ignorance, loop/recur simply feels like a low-level loop where its binding has a nice aesthetic just like `let`
12:40	llasram	noncom: If there's an identifier in scope which refers to a function, you can just pass the identifier to the macro, and the macro can expand to code referring to the function via identifier
12:40	technomancy	dobry-den: it is a low-level loop
12:40	dobry-den	I'm talking to someone that suggests that loop/recur is unpleasant and it only exists to address a jvm limitation
12:40	technomancy	application-level logic should always be expressed in higher-order terms via the seq api
12:41	TimMc	dobry-den: In a language with tail-call optimization, my example's call to foo would replace the current stack frame with the new call.
12:41	noncom	llasram: will it expand to the original form of the function or resolve to the compiled form?
12:41	TimMc	Clojure on extant versions of the JVM can't support that, so we have loop/recur.
12:42	llasram	noncom: It'll expand to exactly the same code using the identifier you'd write by hand
12:42	TimMc	It does basically the same thing, but is much more limited.
12:42	dobry-den	TimMc: Even so, loop/recur is sort of like an "anonymous loop" compared to your named-fn example.
12:42	seangrove	Wish they'd hold EuroClojure in SF, would be a lot more convenient
12:42	noncom	llasram: thanks!
12:42	TimMc	dobry-den: It's an anaphoric named-let.
12:43	Creap	marcopolo2: I thought that (symbol "foo.bar/baz") would work
12:44	Creap	but I guess I misunderstood symbol
12:44	dobry-den	TimMc: Right, and that seems like useful construct to have in a language. I'm admittedly ignorant of these things but I was trying to suggest to someone that loop/recur is actually a nice construct for a language to have.
12:45	justin_smith	a better analog to loop/recur in cl would be tagbody (with the special case of one tag at the top) - but that is very low level and only used when you are optimizing performance (and usually want multiple tags rather than a case statement or if or something)
12:45	technomancy	dobry-den: in practice you only use loop/recur for things that can't be framed in terms of seq operations, which is almost never
12:45	justin_smith	or am I thinking labels? it has been a while
12:46	llasram	technomancy, dobry-den: seq operations / the CollReduce protocol
12:46	rasmusto	looping in low places
12:47	justin_smith	yeah, looking at the docs I was right the first time tagbody, one label at the top, and "go" instead of recur
12:47	justin_smith	that still isn't right though - go does not take args
12:47	justin_smith	never mind, none of this is all that relevant anyway
12:49	dobry-den	technomancy: So let's say you were implementing Hy (http://docs.hylang.org/en/latest/language/api.html#builtins) - Would you not implement loop/recur?
12:49	dobry-den	And what would you implement instead as your "lowest level loop"
12:51	technomancy	dobry-den: I'm not saying it's not needed in the language; I'm saying it's more of an escape hatch. lots of higher-level functionality that comes with the language needs to be implemented in terms of loop/recur, but the day-to-day programmer never sees it
12:51	Creap	I would expect (var ((symbol "clojure.string" "join")) "_" [1,2]) or ((symbol "clojure.string" "join") "_" [1,2]) to work, why don't they?
12:52	dobry-den	technomancy: The person pointed out to me that Clojure is the only lisp with loop/recur as evidence that it's a hack
12:53	technomancy	haha
12:53	technomancy	have you seen CL's LOOP?
12:54	dobry-den	Yeah, he actually directed me there as the pinnacle of looping in lisp
12:54	technomancy	hahahaha
12:55	technomancy	doesn't sound like someone who will listen to reason
12:55	justin_smith	Creep: in the virst example you just have the parens around the call to var balanced wrong
12:56	dobry-den	The context here is that I'm in #hy trying to defend loop/recur in worlds abroad and #clojure just isn't giving me the amunition I need to subjugate the heathens.
12:57	gfredericks	clojurebot: #clojure is wussy about heathen subjugation
12:57	clojurebot	Ack. Ack.
12:57	technomancy	dobry-den: it's true that you don't need loop/recur in languages with guaranteed TCO, but CL and elisp don't have guaranteed TCO either; they have horrible iterative hacks
12:57	dobry-den	This Hy lang is built on Python fwiw
12:57	arrdem	dobry-den: just use loop/recur to run circles around them. they're unfortunate enough to be atop cython, shouldn't be hard.
12:57	justin_smith	Creap: never mind, there is more wrong there than that, but there is a version of that first that works, working on it
12:58	dobry-den	I know python doesn't have tail call optimization, but I suggestd that it doesnt matter because loop/recur is so elegant that it can be implemented with assignment.
12:58	justin_smith	Creap: ##((resolve (symbol "clojure.string/join")) "_" [1,2])
12:58	lazybot	java.lang.SecurityException: You tripped the alarm! resolve is bad!
12:58	justin_smith	,((resolve (symbol "clojure.string/join")) "_" [1,2])
12:58	clojurebot	"1_2"
12:58	justin_smith	:P
12:59	justin_smith	ahh, there we go
13:00	igstan	is there any reason clojure has loop/recur instead of normal name-based TCO? other than as a hint for the compiler that it should complain if the functions isn't actually tail-recursive?
13:01	technomancy	igstan: having it refuse to compile in non-tail-positions is the reason, yeah
13:01	justin_smith	Creap: the reason var acts so weird is it is a macro, it only works if the thing it gets is directly a symbol - a form that resolves to a symbol only comes in as the form, not the resulting symbol
13:01	dobry-den	arrdem: haha yes. disappear into a trapdoor of recurs
13:01	igstan	technomancy: thanks
13:01	technomancy	I think scala does what you suggest, but there's no way to have the compiler enforce non-stack-consuming recursion IIRC
13:02	igstan	technomancy: scala has an annotation @tailrec. it will do TCO without it, but only complain about non-TCO code if you add the annotation
13:03	technomancy	gotcha. so this is basically a macro to do the same thing.
13:03	justin_smith	what I like about recur is the explicit error if not in the tail position - you don't get as many mystery overflows from small errors or bad refactorings
13:04	igstan	technomancy: it just occurred to me that clojure could have used metadata for this?
13:04	igstan	similar to the scala annotation
13:05	technomancy	igstan: yeah, that could probably be used to do the same thing
13:05	technomancy	igstan: but you'd still need a way to recur to a loop-point that wasn't the function entry point
13:05	technomancy	so you couldn't get rid of recur entirely
13:06	igstan	technomancy: it's true, that's what I was thinking right now. in scala I always end up with an inner go helper functions that is tail-recursive and carries the accumulator
13:08	Creap	justin_smith thanks!
13:08	wakeup	What could be the reasons for a function to throw a NullPointerExc. only when used in pmap?
13:09	wakeup	The function looks like this: (fn [out str] (.write out str))
13:09	wakeup	it also calls .flush on out
13:09	wakeup	it also calls pr-str
13:09	justin_smith	wakeup: using with-* macro or binding a special var so that the resource you want does not exist by the time a parallel thread looks for it?
13:09	wakeup	and get
13:09	wakeup	Yes I found the binding issue
13:09	justin_smith	wakeup: are you using with-open to open the out?
13:10	wakeup	justin_smith: No.
13:10	justin_smith	so what was it?
13:10	wakeup	I use Socket.
13:10	wakeup	no I am past that binding issue
13:10	wakeup	was clueless for hours
13:11	wakeup	I still get a NPE
13:12	wakeup	could it be a variable bound by let outside of pmap?
13:13	tbaldridge	wakeup: very much so, pmap will use multiple threads to execute the function. bindings are sometimes not there, or not what you expect.
13:13	tbaldridge	wakeup: but doing IO inside of pmap is just....wrong.
13:13	justin_smith	since pmap is mp, the form that launches pmap can exit before all the parts of pmap are done
13:13	mdrogalis	tbaldridge: Is that necessarily true? That's how you pipeline in Datomic.
13:13	wakeup	hmm no thats not it
13:13	justin_smith	tbaldridge: yeah, good point, I would expect weird overlapping output to the socket
13:14	wakeup	tbaldridge: I am using pmap to test IO operations for thread safety...
13:14	tbaldridge	mdrogalis: let me re-phrase that...doing side-effecting IO inside of pmap is troublesome.
13:14	wakeup	tbaldridge: alternatives?
13:15	tbaldridge	wakeup: future would be a good one.
13:15	mdrogalis	tbaldridge: How is that any different? Haha.
13:15	justin_smith	yeah, a doseq or dotimes launching futures that use the Socket would work nicely
13:15	tbaldridge	mdrogalis: doing reading IO is fine, you're not modifying anything (and based on the datastore may not actually modify any state).
13:15	gfredericks	I wrote a pdoseq the other day
13:16	mdrogalis	Pipelining into Datomic isn't reading IO though
13:16	gfredericks	not as featured as doseq though
13:16	mdrogalis	If I understand what you're saying correctly
13:17	tbaldridge	mdrogalis: I'm not sure what you mean.
13:17	mdrogalis	tbaldridge: Eh, nevermind. It's not really important. I think I get your point.
13:17	noncom	,('a)
13:17	clojurebot	#<ArityException clojure.lang.ArityException: Wrong number of args (0) passed to: Symbol>
13:17	noncom	,('a 1)
13:17	clojurebot	nil
13:17	noncom	,('a 1 4)
13:17	clojurebot	4
13:17	noncom	,('a 3 5 1)
13:17	clojurebot	#<ArityException clojure.lang.ArityException: Wrong number of args (3) passed to: Symbol>
13:18	noncom	why is that ^^ ?
13:18	noncom	what does mean passing 1 or 2 args to a symbol?
13:18	tbaldridge	noncom: calling a symbol as if it were a function treats the 1st argument as a hashmap. if you give it a 2nd argument it gives a default
13:18	justin_smith	noncom: symbol as a called thing is a lookup in a map
13:18	justin_smith	so it is just like (:key {} :default)
13:18	tbaldridge	noncom: 1 argument "can't find 'a in 1", 2 arguments "can't find 'a in 1, so I'll return default"
13:19	noncom	oh, wow, i see! thanks!
13:21	broquaint	,('a {'a "Like so"})
13:21	clojurebot	"Like so"
13:21	broquaint	,('a {'b "Like so"} "Defaulty")
13:21	clojurebot	"Defaulty"
13:21	jonasen_	si14: They really like their macros over at prismatic :)
13:24	dnolen	CLJS users - do people really have strong opinion that the lower level try* is gone - it could be used for catching all errors even non error values - I don't really see the point given how people actually write libraries.
13:24	dnolen	from what I call tell for all browser errors, Foo instanceof Error will be true
13:27	dnolen	so only thing you can't catch is stuff like throw "Foo" which honestly is pretty silly and not something I think JS libs generally do
13:31	gfredericks	dnolen: I don't expect to have a strong opinion about this, but FWIW I can't even parse your sentences to figure out what you're asking
13:31	gfredericks	might just be lack of context
13:31	justin_smith	I guess it would mess up someone's plan to do continuations in js via try/catch - which would be a silly plan anyway
13:32	justin_smith	gfredericks: any object can be thrown in js, in practice only errors are thrown
13:33	gfredericks	so there was some try* that could catch anything? and that was removed recently? and dnolen is wondering if anybody thinks it should still be available?
13:33	justin_smith	that's how I read it
13:34	gfredericks	does that mean it's not possible to do the cljs analog of (try (a thing) (catch Throwable t (cleanup mess) (throw t)))
13:34	gfredericks	where (cleanup mess) only applies to errors and so couldn't be stuck in a finally
13:34	dnolen	gfredericks: try* could catch anything, same way as try can catch anything in JS
13:35	dnolen	gfredericks: most host errors will be instances of Error, so that more or less works
13:35	gfredericks	dnolen: so now it's impossible to catch non-Errors?
13:35	dnolen	gfredericks: but if user code throws a string or a number, you can't catch it
13:35	dnolen	gfredericks: but I'm not convinced that's something worth caring about
13:35	dnolen	if a library is throwing strings ... rage face
13:35	gfredericks	that sounds like a problem for a lib that wants to be able to excute user code and cleanup issues if any exception is thrown
13:35	justin_smith	it would prevent porting slingshot - don't know how big a deal that is
13:35	justin_smith	https://github.com/scgilardi/slingshot
13:36	gfredericks	and my point is that it doesn't have to be a library doing the messy thing -- it could be a user where a library wants to not break just because a user was messy
13:37	dnolen	gfredericks: no, any host error will be an instance of Error, the only thing that won't work if library code explicitly throws non Errors
13:37	gfredericks	users can throw non errors though
13:37	dnolen	gfredericks: CLJS users?
13:37	gfredericks	ye
13:37	gfredericks	s
13:37	dnolen	gfredericks: won't happen cause you can't catch it
13:37	gfredericks	users won't throw them?
13:38	gfredericks	oh throw will check
13:38	gfredericks	I see
13:38	dnolen	gfredericks: if they do they won't be able to catch it
13:38	dnolen	gfredericks: the only problem is external libs that might do this
13:38	gfredericks	what will (throw "foo") do?
13:42	dnolen	gfredericks: it will throw something you can't catch
13:42	dnolen	gfredericks: more or less consider that undefined behavior
13:42	justin_smith	fwiw talking to the js expert here, almost nobody in idiomatic js uses throw, because it totally breaks the page if not caught, so they use things like console.assert instead
13:44	TimMc	"breaks the page"?
13:45	justin_smith	all js stops running
13:45	TimMc	That sounds incorrect.
13:45	si14	jonasen_: yeah :)
13:45	TimMc	justin_smith: I'm gonna need a demo of this.
13:46	justin_smith	TimMc: this is a web shop, we see this all the time - if you have js that throws and uncaught exception, all your js on that page stops running
13:46	justin_smith	I could make a minimal example maybe (though I am not on the js side of things here)
13:47	gfredericks	maybe you're miscommunicating? the thing it sounds like you're saying contradicts my ten years or something of working in web browsers
13:47	justin_smith	maybe
13:48	gfredericks	e.g., if you add a click handler to an element that logs to the console and then throws. and then you clicked twice. how many logs would you expect?
13:48	jonasen_	dnolen: I wouldn't be suprised if there were js libs out there that throws strings
13:49	dnolen	jonasen_: I've never seen one that I'd want to use.
13:49	gfredericks	jonasen_: dnolen: it seems super common in clj-jvm libs to want to be able to catch _all_ throwables for some purpose or another. the idea that something could sneak through because a user is ignorant is troubling
13:49	dnolen	jonasen_: or that anyone I know would want to use - exist is one, pervasive is another
13:50	dnolen	gfredericks: yes, but real the question is whether it actually matters at all for most interop. I'm inclined to say no.
13:50	jonasen_	dnolen: that
13:50	bitemyapp	justin_smith: wat
13:50	jonasen_	's true
13:51	bitemyapp	justin_smith: So Mozilla is telling people to do things that break web browsers? -> https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Statements#Exception_Handling_Statements
13:51	justin_smith	bitemyapp: gfredericks: sorry, it appears I didn't actually understand the problem on the js side of things
13:51	justin_smith	mea culpa
13:52	bitemyapp	justin_smith: it's okay, i was just hella confused and thought I was in an alternate universe where JavaScript is even worse than usual.
13:53	justin_smith	I've had frontend guys say "this happens because any error just stops all the rest of the scripts" - clearly that was an oversimplifications
13:53	gfredericks	bitemyapp: also if you use the variable "foo" anywhere in your file it causes the browser to interpret the statements in reverse
13:53	justin_smith	or a specific case, or something
13:53	jonasen_	http://www.devthought.com/2011/12/22/a-string-is-not-an-error/ "An unfortunately common pattern in Node.JS"
13:53	jonasen_	dnolen: ^ That's all I was able to find on the matter
13:53	TimMc	justin_smith: If they have a big init function and it throws part way, sure, that will break the app.
13:54	bitemyapp	which is also not a good way to write JS code.
13:54	bitemyapp	You can have a callback that does nothing but throw an exception in JS, but as long as the binding is still valid, that callback will keep getting called and keep throwing exceptions.
13:54	justin_smith	ahh, ok
13:54	bitemyapp	All that stuff is independent of each other, you have to write your code in big monolithic blocks to short-circuit behavior.
13:55	bitemyapp	anything that's part of the event loop is unkillable unless you explicitly: https://developer.mozilla.org/en-US/docs/Web/API/EventTarget.removeEventListener
13:55	bitemyapp	or unless you capture the event and preventDefault
13:56	bitemyapp	I'm sure dnolen could think of other ways. You get my meaning.
13:56	bitemyapp	justin_smith: I take it you're mostly backend?
13:56	justin_smith	yeah, all I know about frontend is when things break between the two I guess
13:58	justin_smith	I thought I knew a bit more before this conversation than I think I know now, for sure :)
13:59	bitemyapp	justin_smith: ego is the enemy of learning.
13:59	justin_smith	definitely
14:05	jonasen_	dnolen: I can prepare a patch for CLJS-620. Do you think it's a good idea to defina a (definline ...) macro that expands to (defmacro ^:inline ...) or should I explicitly add ^:inline metadata?
14:05	dnolen	jonasen_: lets just stick with ^:inline for now
14:06	jonasen_	dnolen: ok
14:24	jonasen_	dnolen: uploaded. Note that I made it an error, so this might break some libraries that are immitating cljs.core
14:24	jonasen_	dnolen: I can change it to a warning if you want to
14:28	dnolen	jonasen_: I prefer it be a warning - I think the warning/error behavior should be tunable via cljsbuild
14:31	amacdougall	I'm having an issue with enfocus, and in hopes of debugging it, I decided to fork the repo and experiment. Turns out I was embarking on a whole new adventure! Any advice on how to use a local copy of a library in a project?
14:32	amacdougall	I've tried making a local jar and installing it in a local Maven repo, following http://nakkaya.com/2010/03/16/adding-custom-libraries-into-local-leiningen-repository/ -- but it's failing in a way that hints that I may be on the wrong track.
14:34	amacdougall	First I had to specify a domina dependency in the client project for cljsbuild to work, and after doing so, my JS immediately dies with "Uncaught Error: Namespace "goog.string" already declared." (which doesn't seem like something that should be occurring under any circumstances)
14:35	jonasen_	dnolen: In that case we'll get several warnings so this change might not be much of an enhancement: https://www.refheap.com/19838
14:43	coventry	amacdougall: I generally use lein checkout dependencies for that. https://github.com/technomancy/leiningen/blob/master/doc/TUTORIAL.md#checkout-dependencies
14:44	coventry	(Lets you modifiy the library you're bringing in without doing the lein install dance each time.)
14:47	amacdougall	That might do the job! I'll try it out now and let you know.
14:48	amacdougall	Do I simply put a path to the folder that has the library's project.clj and let Leiningen figure out the rest?
14:48	amacdougall	Because THAT would be a godsend. And yeah, it sure looks like it...
14:48	coventry	Yep. cd my-project; mkdir checkouts ; cd checkouts; ln -s /path/to/dependency
14:49	coventry	Then stick the dependency in project.clj, restart your repl, and play.
14:53	amacdougall	While I'm working, I suppose I should state the issue I'm trying to debug, in case anyone has ideas -- I'm using enfocus's "listen-live" function to handle clicks on <a class="internal"> links, cancel link navigation, and use client-side routing. enfocus/listen worked fine with a (.preventDefault e) side effect... enfocus/listen-live does not! It runs the handler, but the browser navigates anyway.
14:54	amacdougall	Looking at https://github.com/ckirkendall/enfocus/blob/master/project/cljs-src/enfocus/events.cljs, it looks like listen-live builds a goog.Event from the native DOM event, while listen does not. And goog.Event.prototype.preventDefault doesn't seem to actually invoke the native .preventDefault...
15:00	coventry	Oh, also, you have to (require :reload) the dependency to pick up changes since the ns was last loaded.
15:01	bitemyapp	coventry: (require '[clojure.tools.namespace.repl :refer [refresh]]) (refresh)
15:02	amacdougall	coventry: The checkouts version works like a charm, thank you! Unfortunately, I'm still getting the same error as when I used the local jar, and it's a weird one -- it's claiming that "Namespace "goog.string" already declared", but it's the very first time it's executing main.js!
15:02	amacdougall	...it must be executing something else before that... wait, I just might be stupid. Never rule that out.
15:04	coventry	bitemyapp: Sometimes that's been slow for me.
15:04	amacdougall	Yeah, problem solved. This will be very helpful! Thanks, coventry.
15:04	coventry	No worries.
15:09	dnolen	jonasen_: hrm why are there multiple warnings there?
15:09	jonasen_	dnolen: because analysis continues if we emit a warning
15:10	dnolen	jonasen_: but why two warnings for 1 when?
15:10	bitemyapp	coventry: figured I'd offer the more robust solution :P
15:11	jonasen_	dnolen: no idea ...
15:11	dnolen	jonasen_: I'm pretty sure the second one can be supressed
15:11	dnolen	jonasen_: is that in the REPL?
15:12	jonasen_	dnolen: yes
15:12	dnolen	jonasen_: ok so the REPL does two analysis passes is why
15:13	achin__	@technomancy: I'm using your Clojure build pack on Cloud Foundry. I got it to work, but had to munge PATH to include java/bin. I thought the Java buildpack installed the JDK to $BUILD_DIR, not $HOME. http://git.io/fmisbg
15:13	dnolen	jonasen_: in general we don't emit warnings w/o first checking that the user wants to see them, :undeclared is what we normally check for in cljs-warnings dynamic hash-map
15:14	dnolen	jonasen_: we might want to check for something else, or just rethink cljs-warnings and make it a bit simpler.
15:14	jonasen_	dnolen: yeah, I also realized that resolve-var shouldn't call warning explicitly, It should go via resolve-existing-var or something
15:15	jonasen_	dnolen: as the docstring for resolve-var suggests
15:18	amacdougall	Aha... enfocus's events/listen-live actually throws away the original DOM event, passing a completely new goog.events.Event to the client. preventDefault and stopPropagation become impossible.
15:18	amacdougall	Sternly resisting the temptation to make jokes about .preventDefault and the US government.
15:34	Creap	is there a way to auto-restart my app, run with lein run, when it crashes?
15:38	mtp	use runit
15:39	Creap	ok, I'll look into it
15:40	mtp	:)
15:41	mtp	it's a great thing. you also don't have to use the whole thing, if you just need runsvdir.
15:41	mtp	most people just need runsvdir
15:43	llasram	(inc mtp)
15:43	lazybot	⇒ 1
15:44	wakeup	Can anyone give me an example of a simple threadsafe counter?
15:44	llasram	##(java.util.concurrent.atomic.AtomicLong.)
15:44	lazybot	⇒ 0
15:45	llasram	mtp: runit is the best. All nice and Unix-y, but without totally rejecting the FHS like djb's originals
15:46	Creap	mtp: excellent, that took me <5 minutes, thanks
15:46	mtp	:)
15:47	wakeup	Why does this not work:
15:47	wakeup	(dosync (ref-set cnt (inc (deref cnt))))
15:47	wakeup	(try STUFF-HERE
15:47	wakeup	(finally (dosync (ref-set cnt (dec (deref cnt))))))
15:47	wakeup	?
15:47	mtp	i'd like, at some point, to merge s6-supervise with runit
15:47	mtp	later, tho. :)
15:48	mnemnion	I have a hopefully quick if noobish question. I have, basically (do (make a directory) (put stuff in it))
15:48	coventry	wakeup: how does it fail?
15:48	indigo	wakeup: Why not use atoms instead?
15:49	wakeup	coventry: the value of (deref cnt) seems to be unpredictable.
15:49	gtrak	wakeup: works as expected to me
15:49	wakeup	(when used concurrently)
15:49	mnemnion	I think the problem is that clojure is trying to (put stuff in it) before (make a directory) returns
15:49	indigo	(def i (atom 0)) (swap! i inc)
15:49	coventry	wakeup: Well, you don't have it locked during the try block.
15:49	mnemnion	because when I do them one at a time on the REPL, no problme.
15:50	gtrak	seems like you should use alter insted of ref-set? (unrelated)
15:50	indigo	Or, you know, use atoms ;P
15:51	gtrak	this sounds like xy-problem http://www.perlmonks.org/?node_id=542341
15:51	wakeup	coventry: why would I? (honest question)
15:52	llasram	mnemnion: Clojure doesn't have any implicit laziness. Unless you're doing `(make a directory)` as part of realizing a lazy-seq, `do` always evaluates body forms in order
15:53	indigo	wakeup: What are you trying to do
15:53	mnemnion	llasram: okay. what seems to be happening is that the system call isn't actually completing before the next form evaluates.
15:53	coventry	wakeup: The question from my perspective is why you would expect the value to be predictable, given that cnt could be concurrently modified during the try block.
15:53	wakeup	indigo: cound the number of open connections (concurrently)
15:53	wakeup	count*
15:53	TimMc	wakeup: While your code is executing STUFF-HERE, another thread is molesting your refs.
15:53	mnemnion	even though the (make a directory) form returns successfully.
15:53	indigo	wakeup: Then you should use an atom
15:53	wakeup	I will try an atom
15:54	llasram	mnemnion: Post full reproducing code? Can't say what is going on w/o, but I assure you that there isn't random out-of-order execution happening
15:54	TimMc	wakeup: If you're just counting the number of threads that are executing STUFF-HERE, your code should work (although it is a bit awkward.)
15:55	TimMc	What is your evidence that the result of teh deref is "unpredictable"?
15:55	wakeup	TimMc: it doesn't though
15:55	mnemnion	llasram: sure, the only dependency is me.raynes/fs. I'll toss up a gist. thanks!
15:55	wakeup	TimMc: I open 10 connections, then I close them, then the value is random
15:55	Raynes	My code is like an infection. Spreads hate and anger to all who depend on it.
15:56	wakeup	TimMc: obviously I am doing something wrong ;)
15:57	tbaldridge	wakeup: use alter instead of ref-set. that should help
15:57	coventry	I would experiment with tracing output in the finally blocks.
15:58	arrdem	Raynes: could be worse, it could not work while doing all the above.
15:58	wakeup	tbaldridge: would you also suggest using atoms instead?
15:58	mnemnion	https://gist.github.com/mnemnion/6997178
15:58	tbaldridge	the problem is that but yeah, use an atom
15:58	tbaldridge	typeo there.
15:59	wakeup	Btw, I got rid of my NPE's by using futures instead of pmap. Can you guys explain me thats the difference of spawing a lot of futures and pmap?
15:59	tbaldridge	yes, use an atom
15:59	lynaghk	cemerick: ping
15:59	TimMc	tbaldridge: Actually, I'm not seeing why this wouldn't work.
15:59	TimMc	You think there needs to be an ensure? :-/
15:59	mnemnion	llasram: the pieces all work. I can call them one at a time at the REPL and it does what I want.
15:59	llasram	mnemnion: Yeah, so `map` explicitly returns a lazy sequence. You need to force it (probably via `dorun`) in this case, or use a non-lazy form like `doseq` instead
15:59	llasram	(in `athena-gen-dirs`)
16:00	mnemnion	llasram: thanks again! The consequences of laziness on side-effect producing code still bite me.
16:00	llasram	mnemnion: When you call the functions in the REPL they work because printing forces the full seqs to be realized
16:00	llasram	mnemnion: Yeah, it's tricky, especially at first!
16:01	tbaldridge	TimMc: I think alter implies ensure, not sure if ref-set does.
16:01	mnemnion	llasram: I intuited a laziness problem, that's where the 'do' came from, but it's in the wrong place. I see that now. cheers
16:02	tbaldridge	wakeup: the pmap vs futures thing may come down to a matter of bindings, but your new solution is sound. Side effects should be done in futures not in pmap.
16:02	mnemnion	....and it works! ...and it was the last thing that needed to work! I am in a fine mood now. Kudos llasram.
16:03	llasram	mnemnion: Glad to help :-)
16:04	wakeup	tbaldridge: Imho this behaviour is quite buggy, I literally spent 4 hours trying to figure that one out.
16:04	lynaghk	e
16:04	llasram	Oh man, I wish
16:04	wakeup	and I didn't even use binding
16:05	wakeup	The NPE doesn't help one bit...
16:05	lynaghk	Ugh, sometimes my desktop goes "beep" and all of the windows and buttons stop working. But the music keeps playing. Linux...
16:05	wakeup	lol
16:05	wakeup	sounds like windows ;)
16:05	tbaldridge	wakeup: there's certain facts about Clojure semantics that are easy for beginners to miss. For instance, pmap uses multiple threads and bindings may not be passed around. You shouldn't deref a ref inside a dosync, etc.
16:06	tbaldridge	These things all come with time
16:06	lynaghk	wakeup: are you kidding? I should just compile xmonad for Windows 2000 and be done with all of my hardware problems.
16:06	wakeup	lynaghk: Windows 2000 does indeed rock. I make my mum use it on a 15 year old thinkpad.
16:07	coventry	Why shouldn't you deref a ref inside a dosync? I haven't used transactions much yet.
16:08	wakeup	I am afraid what will happen when no browser support win2k. Her office suite doesn't support >xp and nobody could possibly ask her to learn to use a modern MS office.
16:08	TimMc	deref is fine inside a dosync, just make sure to use ensure (if it matters.)
16:10	coventry	Oh, I see how wakeup's code could be failing, and why using alter fixes it. Thanks.
16:10	tbaldridge	coventry: yeah, I think that's the problem. From what I can tell (I might be wrong) if you use deref inside a dosync (without a ensure) the transaction will not be restarted if that ref is modified.
16:10	wakeup	Using atoms has the same effect...
16:10	coventry	tbaldridge: Yes, the refs page on clojure.org is pretty explicit about that possibility.
16:11	coventry	wakeup: You need to make the changes atomic using swap! for an atom or alter for a ref.
16:12	coventry	What is happening is you have multiple threads coming in, reading the value of cnt and trying to inc/dec it at the same time.
16:13	coventry	If you use one of the functions which take an altering function instead, there won't be an opportunity for modification between the read and the inc/def.
16:13	TimMc	wakeup: Could not reproduce with: https://www.refheap.com/19843
16:13	TimMc	I'd be interested in a SSCCE.
16:15	pjstadig	a deref and ref-set inside of a dosync should be fine
16:15	indigo	TIL SSCCEE
16:15	indigo	Er E
16:16	coventry	TimMc: Try taking the delays out.
16:16	wakeup	still works
16:16	wakeup	weird
16:17	TimMc	coventry: Still works.
16:17	TimMc	coventry: Let me know if you find something.
16:17	coventry	cnt has a value of 7 after running https://www.refheap.com/19844 for me.
16:18	tbaldridge	and if you use alter?
16:18	indigo	Hm, still has a value of 0
16:18	pjstadig	coventry: you probably need to reref the futures
16:18	wakeup	When I use alter the system deadlocks
16:18	pjstadig	er deref
16:18	TimMc	coventry: Are you sure all those threads have finished? :-P
16:18	tbaldridge	wakeup: how are you using alter?
16:18	wakeup	inside a dosync?
16:18	tbaldridge	should be (alter cnt inc)
16:18	wakeup	(alter ref inc)
16:19	TimMc	I do not believe that ref-set is not strictly stronger than ensure.
16:19	wakeup	in a dosync right?
16:19	tbaldridge	yep
16:19	indigo	coventry: It has a value of 145 if I do it with 2000 threads
16:20	pjstadig	indigo: then you are not waiting for the 2000 threads to finish before checking the value
16:21	pjstadig	alter is better style than deref/ref-set, but not different semantics
16:21	indigo	pjstadig: Ah, gotcha
16:22	wakeup	I am now using alter and still getting random values....
16:22	coventry	TimMc, pjstadig, You're right, cnt is zero if I delay a second before checking it.
16:22	TimMc	~sscce
16:22	clojurebot	An SSCCE is a Short, Self-Contained, Correct Example <http://sscce.org/>
16:22	indigo	^
16:22	pjstadig	wakeup: you need to paste the exact code
16:23	TimMc	wakeup: ^ Post an SSCCE demonstrating how you get those "random" values.
16:23	TimMc	You are misinterpreting your results.
16:23	pjstadig	there's probably an unrealized lazy seq, or otherwise un-joined threads that are causing "randomness"
16:26	coventry	wakeup: Are you sure all your threads are finished when you check the value of cnt? Tracing the finally blocks could help determine that.
16:37	cemerick	lynaghk: heyo
16:39	dobry-den	Is there a way to throw a Warning to the user?
16:42	indigo	dobry-den: https://github.com/clojure/tools.logging ?
16:43	dnolen	feel free to chime in the try* change if you are likely to be affected by it, http://groups.google.com/forum/#!topic/clojure-dev/1ahsYtzFbJg
16:43	bitemyapp	dobry-den: [com.taoensso/timbre "2.6.2"] (:require [taoensso.timbre :as t]) (t/warn "you have been warned")
16:44	dobry-den	thanks yall
16:46	Jarda	timbre seems cool
16:46	justin_smith	it even optionally does colors for tty output
16:47	justin_smith	I wish you could set out to be a specific output stream for timbre though - things still get weird under emacs/nrepl it seems
16:47	lynaghk	cemerick: hey dude
16:47	lynaghk	cemerick: I saw you had some patches submitted to amazonica and I was going to ask you a few questions about what you're using it for
16:48	lynaghk	I'm thinking about using S3 as a store for small (128kB-ish chunks) and basically need to use a gazillion threads to get any kind of throughput with that
16:48	lynaghk	I decided to just use the java bits manually rather than figure out how to out-reflect amazonica, though.
16:50	bitemyapp	lynaghk: are the throughput limitations due to how slow S3 is or something else?
16:50	cemerick	lynaghk: Using it for s3 + dynamo at the moment
16:51	lynaghk	bitemyapp: I think the HTTP negotiation latency dominates the transfer time
16:51	bitemyapp	lynaghk: that's what I would figure. Is there some reason you couldn't use Riak+Bitcask, Dynamo, or something else?
16:51	lynaghk	bitemyapp: there's an (old) analysis of S3 stuff here: http://improve.dk/pushing-the-limits-of-amazon-s3-upload-performance/
16:52	lynaghk	bitemyapp: inexpensive storage is more important that latency---things will be synced to the end machines and cached there
16:52	lynaghk	I just want to make sure there's bandwidth for the syncing
16:53	cemerick	lynaghk: I've not bothered benchmarking my s3 puts. Fast Enough, etc.
16:53	lynaghk	cemerick: yeah. the main issue I was having with amazonica is that everything is magic---I couldn't figure out how to twiddle the Java client options
16:54	cemerick	dropbox was (still is?) built on s3, so I suspect it's not going to get in your way, perf wise, at least until you're up at some serious scale
16:54	cemerick	lynaghk: gotta use it with the javadocs open
16:54	amacdougall	coventry: I was able to debug, fix, and pull-request that library. Thanks again for the help!
16:54	lynaghk	bitemyapp: bitcask looks interesting, thanks for the pointer
16:56	bitemyapp	lynaghk: Riak+Bitcask and HDFS are good alternatives for when you need a bit more magic than S3 offers.
16:56	bitemyapp	I didn't mention HDFS because BC seemed closer to the mark.
16:56	bitemyapp	the LevelDB backend for Riak is for more traditional OLTP workloads.
16:57	bitemyapp	lynaghk: a common tactic in Hadoop shops is to use HBase as an index for content stored in HDFS.
16:58	bitemyapp	so that you have something more sophisticated than just 1-1 URLs if and when needed.
16:58	bitemyapp	you don't want the blobs inline in HBase generally.
16:58	justin_smith	speaking of aws and alternatives, does anyone have experience with using clojure on an openstack? my company uses beanstalk but it would be nice to have options and potentially the extra power you could get with the openstack alternative
16:59	lynaghk	bitemyapp: do you know offhand how difficult it would be to package up bitcask and ship it via an uberjar?
16:59	bitemyapp	lynaghk: approximately as difficult as any Erlang application.
16:59	lynaghk	if I wanted to use it instead of the plain filesystem for a simple k/v cache (a subset of the keys avaliable in S3)
16:59	lynaghk	bitemyapp: no idea how difficult that is = )
17:00	bitemyapp	I'd be comfortable filing it under "ideas that are not good"
17:01	bitemyapp	lynaghk: if you want an embedded kv store, then you should look at kyoto cabinet, derby, and LevelDB
17:01	bitemyapp	there are pure Java ports of LevelDB and a JNI version
17:01	bitemyapp	lynaghk: that's much wiser if you just want an embedded KV store that hits the filesystem.
17:01	lynaghk	bitemyapp: awesome, thanks for the info. will do.
17:01	technomancy	berkeleydb is the old-school choice for embedded kv
17:01	technomancy	old as the hills
17:01	bitemyapp	technomancy: I was trying not to go there.
17:02	technomancy	because Oracle?
17:02	brehaut	those hills rise wild
17:02	lynaghk	ability to uberjar via lein is a big requirement
17:03	bitemyapp	lynaghk: the most robust answer for an uberjar environ is probably H2/Derby/HSQLDB. LevelDB and Kyoto Cabinet are going to mean either JNI or a port.
17:03	llasram	I've never actually used berkeleydb, but there's this great line in the `reprepro` BUGS section: "Reprepro uses berkeley db, which was a big mistake."
17:03	lynaghk	bitemyapp: you know if any of those have an idiomatic clojure API for doing, e.g., keyset intersections and batch lookups/writes?
17:04	lynaghk	the keys are derived from the content, so everything immutable
17:04	bitemyapp	lynaghk: you want Derby/H2/HSQLDB and to just use SQL then.
17:05	lynaghk	bitemyapp: really? I feel like the overhead of writing 10000 keys into a SQL string would dominate the useful work
17:05	technomancy	IIRC sleepycat had a history of making their license look like a BSD-style license when it was actually copyleft, and then approaching users to work out a licensing deal after they'd already written their code around it
17:05	technomancy	(before they even got acquired by oracle)
17:06	bitemyapp	technomancy: hence why I was trying not to go there.
17:06	bitemyapp	left a bad taste in a lot of peoples' mouths.
17:06	lynaghk	bitemyapp: well, it's all k/v so it shouldn't be too hard to benchmark a few different options. thanks again for the tips!
17:06	technomancy	bitemyapp: well, only if you plan on distributing
17:07	bitemyapp	lynaghk: that's not quite how I would do it.
17:07	indigo	Riak is sexy
17:07	bitemyapp	10000 keys in a query that is.
17:07	lynaghk	bitemyapp: I haven't used those guys before---I'll take a look at the APIs and see if there's a saner way to do batch ops
17:08	lynaghk	it's just the first thing I thought of when you mentioned SQL.
17:08	bitemyapp	lynaghk: leveldb is more designed around batch ops than the SQL options or Kyoto Cabinet.
17:08	bitemyapp	lynaghk: it's built on top of log-structured merge trees. I don't know how applicable it'll be to your problem, it's foreign to me.
17:08	bitemyapp	I do a lot of database stuff and I am baffled by what you just mentioned.
17:08	bitemyapp	I'd need more info than intersecting 10,000 keys.
17:09	lynaghk	bitemyapp: I just mean for a batch operation like, "insert 10000 keys" with SQL I'd have to write a giant query to see which of those keys already exist, subtract, and then write the new ones
17:10	lynaghk	since SQL strings are the only interface to SQL databases---but, like I said, maybe there are some features in the DBs that you mentioned that provide more data-oriented interfaces over just strings.
17:11	bitemyapp	lynaghk: roughly you're talking about "insert where not exists", I don't think the overhead surrounding the SQL string is a big deal when the database is embedded. It's all something that can be measured. Please blogginate if you do.
17:12	lynaghk	bitemyapp: I'd need to spend approx 20x as much work to get a suitable blog post over what I was going to just do in the privacy of my own application
17:12	lynaghk	= )
17:13	bitemyapp	lynaghk: at least toss me an anecdote then :(
17:14	lynaghk	bitemyapp: you have the same handle on github?
17:14	bitemyapp	lynaghk: yes. I was also in Clojure Cup.
17:14	lynaghk	bitemyapp: I'll shoot you an email when I get it all worked out
17:14	bitemyapp	lynaghk: leveldb is generally a couple micros per write and hundreds of nanos per read, with that in mind, doing the "obvious thing" (just iterating) should only take 20-30 millis.
17:14	bitemyapp	lynaghk: is 20-30 millis to sync your 10,000 immutable keys acceptable?
17:14	lynaghk	bitemyapp: yeppers.
17:14	bitemyapp	then you could just do the "obvious" thing in leveldb and verify how long it takes.
17:15	lynaghk	yeah, will probably do that
17:17	bitemyapp	lynaghk: I feel like Hacker News has disincentivized sharing knowledge because if you don't write a perfect post criticisms come out of the woodwork.
17:17	bitemyapp	I find this very sad :(
17:18	brehaut	you can write the perfect post, but someone will have a different perspective where the contents of that post are not relevant and they'll still complain
17:20	lynaghk	bitemyapp: nah, nothing about HN---it just takes me forever to write anything
17:20	bitemyapp	well I'll still be pleased if you toss an anecdote my way :)
17:20	indigo	Fuck it, learn through criticism!
17:20	bitemyapp	indigo: <3
17:20	indigo	:D
18:26	tyler_web	does JAVA_OPTS environment work when running `lein run`, or do I need to add to a project file?
18:29	TimMc	tyler_web: It's an environment variable, so when running `lein run`.
18:29	justin_smith	tyler_web: you can use :jvm-opts in a project.clj, or _JAVA_OPTIONS on the command line
18:30	TimMc	Oh, has the env var changed?
18:31	TimMc	I see JAVA_OPTS and JVM_OPTS in the lein bin.
18:31	justin_smith	I always use _JAVA_OPTIONS
18:32	mklappstuhl	using (try () (catch ...)) is there a way to catch any exception no matter which class?
18:33	technomancy	catching Exception will catch subclasses of Exception too
18:33	justin_smith	and Exception is a subclass of Throwable
18:34	justin_smith	though catching Throwable may be a bit overboard
18:34	technomancy	yeah, don't catch Throwable
18:34	technomancy	you won't be able to stop your program without kill -9
18:36	TimMc	You can safely catch Exception and AssertionError.
18:36	AimHere	But then again, nobody else will be able to stop it too, muHAHAHA!
18:37	mklappstuhl	Ah, that makes sense, thanks!
18:37	gfredericks	catching throwable is often useful if you're rethrowing it
18:37	gfredericks	there was a bug in java.jdbc regarding transaction roleback due to the fact that it _wasn't_ catching throwable
18:37	TimMc	If you get your hands on an OOM error or similar, you want to rethrow it as quickly as possible.
18:38	TimMc	and with minimal allocation
18:38	mklappstuhl	I don't really know what I'm doing. Running a big job saving things to a database and I dont want it to stop if it doesn't work in one instance...
18:38	mklappstuhl	TimMc: OOM?
18:38	gfredericks	yeah just catch Exception for that probably
18:39	mklappstuhl	Will do
18:39	TimMc	out of memory
18:51	dnolen	marcopolo2: are you the author of servant? https://github.com/MarcoPolo/servant?
19:27	dobry-den	Is it possible to write an `unroll` macro so that [(unroll [:a :b :c]) bar] -> [:a :b :c :bar]?
19:29	justin_smith	dobry-den: that macro would need to look out at the thing that contains it
19:29	justin_smith	which is weird
19:29	justin_smith	and probably not at all possible
19:32	turbofail	you could get a similar effect by just using syntax-quote: `[~@[:a :b :c] ~bar]
19:33	turbofail	slightly less convenient, but not too bad
19:33	dobry-den	(conj [:a :b :c] :bar)
19:34	gws	,(flatten [[:a :b :c] :bar])
19:34	clojurebot	(:a :b :c :bar)
19:58	amalloy	dobry-den: unroll is indeed impossible to write; any non-crazy use cases are easily handled with turbofail's suggestion
20:02	marcopolo2	dnolen: yup!
20:11	eriktjacobsen	Hello
20:13	eriktjacobsen	Got a question regarding dependencies. I have some sub projects that all compile fine and use aws javasdk 1.5.8, but my top level project has the bandalore library that uses like 1.3 aws java sdk, and it causes top project to fail to compile… Do I have to patch bandalore to use 1.5.8, or how can I tell it to use two version of aws-java-sdk for each of the individual projects?
20:13	eriktjacobsen	this is using lein
20:15	marcopolo2	eriktjacobsen: can you post your project.clj file on refheap.com?
20:19	eriktjacobsen	marcopolo2: included the relevant paste:
20:19	eriktjacobsen	https://www.refheap.com/19848
20:19	eriktjacobsen	looking at it, perhaps should add rotary to top level project?
20:19	eriktjacobsen	trying that now
20:20	eriktjacobsen	Also perhaps I should take a step back, trying to fix this compile issue: http://stackoverflow.com/questions/19391375/clojure-leiningen-compile-error-with-multiple-projects-classnotfoundexception
20:21	eriktjacobsen	Posted pointed me to the dependencies possibly linking wrong libs, so since the version showing up in top level project (1.3) doesn't have the calls I'm using in 1.5.8, i'm hoping that is the root of my compile issues
20:21	rasmusto	,(for [a nil] a)
20:21	clojurebot	()
20:22	rasmusto	,(doseq [a nil] (println a))
20:22	clojurebot	nil
20:25	dnolen	marcopolo2: pretty cool, but I'm assuming it's not possible to put a piece of data into a worker w/o copying without first partitioning it first into array buffers?
20:25	marcopolo2	dnolen: thanks! yeah, unfortunately that's a limitation in web workers :(
20:26	dnolen	marcopolo2: still very cool, and seems very useful.
20:26	marcopolo2	I wish there was an immutable type you could create and transfer around
20:27	marcopolo2	dnolen: you going to clojure/conj again?
20:28	marcopolo2	also servant made the web worker part of the crypt demo the easiest part! as opposed to the js version where it was the trickiest part!
20:28	dnolen	marcopolo2: yess
20:28	marcopolo2	dnolen: Awesome! :D
20:28	dnolen	marcopolo2: yes, using the channels for the worker pool is really cool
20:29	dnolen	marcopolo2: makes coordination triival
20:29	marcopolo2	dnolen: It really does! I kinda felt like I was cheating
20:39	bja	anyone using tmux to send-keys to their repl encountered issues with send-keys not supporting zoomed panes in tmux 1.8?
21:14	logic_prog	I have written a few macros in the past. I want to better understand how the macro compiletime/runtime works. Is this documented anywhere? [not how to write macros, but a description of when/how macro expansion works in clojure]
21:17	nightfly	Look up documentation for Common Lisp macros
21:17	brehaut	nightfly: thats not especially relevant
21:18	nightfly	How so? They behave practically identical
21:18	nightfly	Unless you do AOT stuff, then all bets are off
21:19	brehaut	logic_prog: https://github.com/clojure/clojure/blob/master/src/jvm/clojure/lang/Compiler.java#L7140 is where to begin with specifics
21:19	logic_prog	brehaut: lol
21:19	logic_prog	actually wait, are you serious?
21:19	brehaut	yeah
21:19	brehaut	maybe im weird in the head, but the clojrue compiler is relatively straightforward
21:20	logic_prog	where the fuck is "the annotated clojure source / rich hickey" ?
21:20	brehaut	you want anotated source? most of use would be happy with non whitesmith source :P
21:20	logic_prog	brehaut: I think the correct word is "genius" not "weird in the head"
21:20	brehaut	logic_prog: im no genius
21:21	Apage43	macroexpand(form) just calls macroexpand1(form) repeatedly until it stops getting a different result
21:21	logic_prog	https://github.com/clojure/clojure/tree/master/src/jvm/clojure/lang is the entireity of the clj source?
21:21	logic_prog	this actually doesn't seem so bad
21:21	brehaut	and theres an isMacro method that is used to determine if a symbol / ref refers to a macro
21:21	Apage43	and macroexpand1(form) will return form unless form is a seq whose first element is a symbol that corresponds to a var in the current ns that is defined as a macro
21:22	brehaut	logic_prog: its the entireity of the low level stuff; core.clj adds a crap ton of the sophisticated syntax and semantics
21:22	Apage43	in which case it will instead return the result of applying the macro fn to the rest of the form
21:23	logic_prog	(defn macroexpand [form] (let [h (head form)] (if (isMacro? h) (macroexpand-1 form) form))) ?
21:23	brehaut	close enough for government work yeah
21:23	Apage43	yeah but in java
21:23	brehaut	so its 75 lines long
21:24	Apage43	also the isMacro check is inside of macroexpand-1
21:24	Apage43	https://github.com/clojure/clojure/blob/master/src/jvm/clojure/lang/Compiler.java#L6530-L6535
21:24	logic_prog	man, that code isn't half bad
21:24	Apage43	macroexpand itself is really short
21:24	logic_prog	it looks readable too
21:25	logic_prog	I feel like I can read the entirety of compieler.java if I just had brehaut/Apage43 as guides
21:26	Apage43	and isMacro just checks is the key :macro is set to true on the Var's metadata
21:27	brehaut	logic_prog: compilers get complicated for about 3 reasons imho: a) monsterously recursive with many cases b) tend to have a lot of layers c) they have to generate a lot of code for all the specific features of the language
21:27	Apage43	(the isMacro in Compiler.java can also take a symbol, in which case it looks up the var, then does said check)
21:27	logic_prog	so clojure avoids this mess by "java has a JIT" ?
21:27	brehaut	logic_prog: clojure's compiler isnt especially layered, and it only has to implement the special forms
21:27	brehaut	logic_prog: it avoids part of the mess due to that yeah
21:28	logic_prog	actually, here's a dumbass question
21:28	Apage43	,(meta #'when)
21:28	clojurebot	{:macro true, :ns #<Namespace clojure.core>, :name when, :arglists ([test & body]), :column 1, ...}
21:28	logic_prog	does clojur'es compiler compile .clj files to .java strings and runs them on the fly, or is the clojure compiler an "interpreter for *.clj files" taht gets JITTed ?
21:29	brehaut	it compiles them to inmemory java bytecode in classes
21:29	Apage43	well the first one definitely doesn't happen. It never generates java source
21:29	logic_prog	Apage43: clojure is more dynamic than I thought
21:29	Apage43	it does generate jvm bytecode though, yes
21:29	logic_prog	I need one more help from the two of you, then I'll stop wasting your time
21:29	brehaut	logic_prog: thats all abstracted away in the asm package though :)
21:29	logic_prog	can you point me at where in Compiler.java clojure does the bytecode generation?
21:29	Apage43	javac : java :: Compiler.java : clj ;; sort of
21:29	logic_prog	I'm kinda interested in this as an alternative to LLVM
21:30	logic_prog	I want to learn how clojure does *.clj -> java asm
21:30	brehaut	https://github.com/clojure/clojure/tree/master/src/jvm/clojure/asm i think
21:30	Apage43	basically all the emit* methods are calls to the ASM library
21:31	Apage43	which does the work of providing a sane way of building java bytecode programatically
21:31	logic_prog	this is fucking badass
21:31	logic_prog	clojure source = my new reading project
21:31	brehaut	logic_prog: part of that magic is that clojure has (if i recall correctly) a custom class loader
21:32	logic_prog	oh, all of https://github.com/clojure/clojure/tree/master/src/jvm/clojure/asm is added 6 years ago
21:32	brehaut	if i recall correctly its a third party library that is bundled with clojure?
21:32	Apage43	http://asm.ow2.org/
21:33	Apage43	"ASM is an all purpose Java bytecode manipulation and analysis framework. It can be used to modify existing classes or dynamically generate classes, directly in binary form. "
21:33	brehaut	reformated in whitesmith probably :P
21:33	brehaut	(https://en.wikipedia.org/wiki/Indent_style#Whitesmiths_style)
21:35	logic_prog	need to eat dinner; thanks to everyone for insightful pointers
22:01	RoboClaudio	Raynes: Many people must be bugging you with this, so I apologise if you recently answered the question, but I'm wondering: is Meet Clojure is still on hold?
22:34	amalloy	RoboClaudio: i'm pretty sure he hasn't worked on it at all recently
22:52	RoboClaudio	amalloy: thanks :)
23:20	technomancy	ten whole minutes
23:21	amalloy	gfredericks: static compiler? i'm not entirely clear on what that means. does clojure have a dynamic compiler?
23:22	brehaut	(def static-compiler (constantly some-binary))
23:23	amalloy	brehaut: that's how ghc works, right? always compiles down to a lazy binary, which loads whatever code it decides you actually need at runtime :)
23:24	brehaut	lol :)
23:24	brehaut	i dont know: ive never had a haskell program compile without a type error
23:24	amalloy	nor with a type error, i should think
23:25	brehaut	well true
23:25	brainproxy	in core.async / its docs, are "channel" and "port" synonyms?
23:26	brainproxy	or they convey a different meaning?
23:26	marcopolo2	brainproxy: yes
23:27	marcopolo2	brainproxy: to the first one sorry
23:27	brainproxy	marcopolo2: thanks
23:30	coventry	I have a macro which is erroring out with a really uninformative stack trace. All it says is that something went wrong in macroexpand1, doesn't even give the line number of the form which caused the arity exception. Is this a common problem with developing macros and if so are there any tricks for getting better stack traces from macros?
23:31	marcopolo2	coventry: I usually play around with (macroexpand1 '(your-macro foo))
23:31	marcopolo2	the will show you what your macro will expand to without running it
23:33	coventry	This is a recursive macro, though. It macroexpands its contents, then wraps the interesting contents of whatever special form is yielded by that, and will recurse on the eval. I suppose I can just trace the output of the macro at each stage.
23:34	talios	'lo brehaut
23:34	brehaut	hi talios
23:35	marcopolo2	coventry: I did something similar a while ago, I ended up changing the inner macroexpands to macroexpand1 to see if I could spot the error
23:35	marcopolo2	coventry: what's the macro?
23:36	amalloy	coventry: "a really uninformative stack trace" is subjective. it's often the case that if you gisted it someone could help
23:36	coventry	marcopolo2: It's a general code-transformation scheme similar to riddley.walk. In this case, I want it to wrap whatever it's passed in tracing/debugging instrumentation.
23:39	brainproxy	marcopolo2: are you aware of a larger set of examples for core.async (i.e. larger than the set in the github repo) which explores the API in more detail?
23:39	marcopolo2	brainproxy: you doing cljs or clj?
23:39	brainproxy	i must admit that it's not clear to the "why" and "how" / "how to" for many of the API features
23:39	brainproxy	marcopolo2: cljs mainly, at this point
23:39	coventry	amalloy: I don't need help to debug in this case, I'm just anticipating difficulties in more complex situations. But I would welcome any suggestions you have about how to read https://www.refheap.com/19855
23:39	brainproxy	for core.async I mean
23:40	brainproxy	clear to *me
23:40	marcopolo2	brainproxy: google david nolen's core.async tests
23:40	gfredericks	amalloy: you done known I was talkin bout static types
23:40	marcopolo2	he has some examples for some core.async cljs stuff
23:41	gfredericks	amalloy: gotta sacrifice clarity if I'm gonna fit my IRC comments within 140 characters
23:41	marcopolo2	brainproxy: but it's pretty simple, in cljs you can just use the go blocks
23:42	brainproxy	marcopolo2: right, playing around already
23:42	marcopolo2	brainproxy: Anything in particular tripping you up?
23:42	brainproxy	no, just looking over the API, which seems to have grown since last time I tinkered
23:42	brainproxy	stuff like onto-chan, admix, mult
23:43	brainproxy	maybe i just didn't look that closely beforehand, not sure
23:43	amalloy	coventry: line 73 of wrap_macro_test, right? contains a call to wrap3/walk-wrap, with the wrong number of args
23:43	brehaut	talios: hows things?
23:43	marcopolo2	brainproxy: o wow, you are right. never saw those before
23:46	coventry	amalloy: No, that is the initial test form. The call to wrap3/walk-wrap is actually in wrap-macro/wrap-form*, a couple of layers down the stack.
23:47	marcopolo2	brainproxy: the source is pretty helpful
23:47	brainproxy	marcopolo2: that is a true statement
23:47	brainproxy	:)
23:47	brainproxy	i just like examples