#clojure – 2015-02-28

2015-02-28

02:55	lvh	Hm
02:58	lvh	So, I am rebinding a dynamic var using a fixture that lives in a different namespace; that namespace then calls the original namespace back, and by the time I get there, the var is unbound again :-(
02:58	lvh	at first I thought it might be some threading shennanigans, but I get the same behavior with with-redefs
03:04	lvh	Ah. Turns out I didn't know how use-fixtures works :)
03:07	niac	user=> (import PiratePhrases)
03:07	niac	ClassNotFoundException PiratePhrases java.net.URLClassLoader$1.run (URLClassLoader.java:372)
03:08	niac	but there is a PiratePhrases.class
03:08	niac	without package
03:26	SagiCZ	i am making java desktop application and i have decided to use clojure to write the gui part.. swing and javafx seem both pretty constricted where it comes to design, i would like to develop the design simliary to web pages, is it possible in clojure? maybe run it in a bundled web browser? i dont know where to start though
03:30	niac	is there any way to use a local java file without lein in clojure
03:33	devll	you can checkout reimport here. niac https://github.com/zcaudate/vinyasa/tree/master/src/vinyasa
03:35	niac	devll: thanks
03:40	sveri	Hi, I wonder if there is an abstraction for korma that let's me insert and update many-to-many entities? It seems like korma itself does not support this usecase
03:42	devll	https://github.com/friemen/aggregate
03:43	devll	I am using yesql ,but aggregate might do what you want sveri
03:47	sveri	devll: uh, another nice library I never heard of, this looks promising, thank you
03:49	devll	:D
04:18	noncom	hi, anyone using ccw here ?
04:37	Eremox	How do I set a distinct documentation string for each arity of a function?
04:39	noncom	Eremox: i think there is no way to do that. if you look at the core clojure functions, they all just describe the arities verbally in a singal description
04:40	Eremox	ok to bad.
04:40	noncom	Eremox: not really, this goes hand-in-hand with the notion that a single function must have a single responsibility and arity overload must not seriously affect the functionality of the function
04:40	noncom	Eremox: so, ultimately, this limitation is for the greater good
04:42	Eremox	I understand but i think it makes the code clear. (I defined a macro.
05:33	SagiCZ	I am trying to add a couple of clojure files to my all java project in intellij but Cursive does not recognize any symbols, what am I doing wrong?
05:34	SagiCZ	oh i know.. i didnt set the directory as source in the project structure.. nevermind it works now
05:34	cfleming	SagiCZ: Do you have Clojure added as a library dependency to your module? And are your Clojure files under a source root?
05:35	cfleming	SagiCZ: Snap, there you go.
05:35	cfleming	SagiCZ: I'm planning to add a popup in the editor when you don't do that, especially for cljs
07:06	SagiCZ	cfleming: thanks!
07:07	SagiCZ	whats the best way to send two state parameter to a function?
07:07	SagiCZ	lets say i have a function that can draw something on TOP or BOTTOM
07:08	SagiCZ	i could do something like (draw x y z true) where true would mean TOP and false would mean BOTTOM.. but i dont like that
07:08	SagiCZ	what about (draw x y z :top) and (draw x y z :bottom) is that a misused keyword?
07:19	raspasov	SagiCZ: have two separate functions? :)
08:22	devll	Hi, after deleting a file in my project,(refresh-all) gives FileNotFount Exception.
08:22	devll	*Found
08:32	devll	doing remove-ns does not help.
08:32	devll	how can I remove this error?
08:33	devll	restarting repl will do it,but it is too costly.
08:43	triss	hey all. am I right in thinking there are no pre and post conditions for defmethod?
08:48	Bronsa	triss: you can add them to the dispatch function
08:49	Bronsa	triss: or even to every defmethod
08:50	Bronsa	,(defmulti m class)
08:50	clojurebot	#'sandbox/m
08:50	Bronsa	,(defmethod m Object [x] {:pre [(string? x)]} x)
08:50	clojurebot	#<MultiFn clojure.lang.MultiFn@6ea5b634>
08:50	Bronsa	,(m "foo")
08:50	clojurebot	"foo"
08:50	Bronsa	,(m 1)
08:50	clojurebot	#<AssertionError java.lang.AssertionError: Assert failed: (string? x)>
08:51	triss	brilliant thanks Bronsa... doesn't look documented to me? http://clojuredocs.org/clojure.core/defmethod
08:52	Bronsa	dunno, I read the impl
08:52	triss	hah. might hve o try nad ge used to that.
08:53	triss	^ have to try and get used to that
11:17	crazydiamond	Hi. Can anyone suggest math/functional programming book with theory and/or exercises for development of functional way of thinking (with Clojure flavour)?
11:17	subhashgo	crazydiamond: I don't know about books, but 4clojure.com is a good resource for clojure exercises
11:24	crazydiamond	subhashgo, thanks
11:25	justin_smith	crazydiamond: have you looked at clojure for the brave and true, and clojure from the ground up?
11:34	gfredericks	clojure {for,from} the {brave,ground} [and] {true,up}
11:37	crazydiamond_	:D
11:37	crazydiamond_	btw, is e.g. lambda calculus useful to know for functional programming?
11:37	justin_smith	,(str "clojure " (rand-nth '[from for]) " the " (rand-nth '[ground brave]) (rand-nth [" and " " "]) (rand-nth '[true up]))
11:37	clojurebot	"clojure from the brave true"
11:38	justin_smith	,(str "clojure " (rand-nth '[from for]) " the " (rand-nth '[ground brave]) (rand-nth [" and " " "]) (rand-nth '[true up]))
11:38	clojurebot	"clojure from the ground and up"
11:38	gfredericks	crazydiamond_: not in too much detail
11:38	crazydiamond_	an, other fields of math?
11:38	crazydiamond_	*and
11:38	justin_smith	crazydiamond_: the lambda calculus is for fp kind of like knowing a machine language (optionally turing tape being that language) is for imperative
11:38	justin_smith	,(str "clojure " (rand-nth '[from for]) " the " (rand-nth '[ground brave]) (rand-nth [" and " " "]) (rand-nth '[true up]))
11:38	clojurebot	"clojure from the brave and up"
11:39	crazydiamond_	so far no matches with "for", btw
11:39	justin_smith	,(str "clojure " (rand-nth '[from for]) " the " (rand-nth '[ground brave]) (rand-nth [" and " " "]) (rand-nth '[true up]))
11:39	clojurebot	"clojure from the brave up"
11:39	justin_smith	,(str "clojure " (rand-nth '[from for]) " the " (rand-nth '[ground brave]) (rand-nth [" and " " "]) (rand-nth '[true up]))
11:39	clojurebot	"clojure for the ground up"
11:39	crazydiamond_	there it is
11:40	justin_smith	finally - that last one is for pigs that want to learn how to program after they become sausage
11:46	gfredericks	(inc justin_smith)
11:46	lazybot	⇒ 199
11:49	justin_smith	haha
12:04	hyPiRion	(inc justin_smith)
12:04	lazybot	⇒ 200
12:04	hyPiRion	do I win something
12:06	justin_smith	you got to be an important part of a very special moment
12:06	gfredericks	~200 is a number made up of only smallish primes
12:06	clojurebot	Ik begrijp
12:07	gfredericks	,(* 2 2 2 5 5)
12:07	clojurebot	200
12:08	justin_smith	,(filter #(zero? (rem 200 %)) (range 1 200))
12:08	clojurebot	(1 2 4 5 8 ...)
12:09	justin_smith	,(clojure.string/join \space (filter #(zero? (rem 200 %)) (range 1 200)))
12:09	clojurebot	"1 2 4 5 8 10 20 25 40 50 100"
12:18	TEttinger	,(clojure.string/join " " (filter #(zero? (rem 200 %)) (range -200 0)))
12:18	clojurebot	"-200 -100 -50 -40 -25 -20 -10 -8 -5 -4 -2 -1"
12:18	TEttinger	nice
12:19	justin_smith	remainder is handy that way
12:21	SagiCZ	does anybody know how could i change the way seesaw button is painted? i know its JButton and in java i would extend it and overwrite the paint method, how to do that in clojure/seesaw?
12:26	emaczen	I need to use the for macro and for some reason this is not visible in my current namespace -- I see that it is part of clojure.core.
12:27	emaczen	nvm I figured it out
12:28	emaczen	but what does :refer all do in a require form?
12:28	SagiCZ	it should be :refer :all
12:29	nuwanda_	it means you get every function in the namespace, as opposed to :refer [functions you want]
12:29	SagiCZ	and it refers all the symbols
12:29	SagiCZ	and yeah.. 'for' should be available everywhere
12:29	emaczen	SagiCZ: What's wrong with omitting :refer :all (it seemed to import the for macro)
12:29	SagiCZ	emaczen: what was before the refer all? what namespace>
12:29	SagiCZ	?
12:30	emaczen	clojure.core
12:30	SagiCZ	you dont need to require clojure.core thats automatic
12:30	SagiCZ	delete the whole statement
12:30	SagiCZ	(ns my-namespace)
12:30	emaczen	But I can't use the for macro otherwise
12:30	SagiCZ	(for [x (range 10)] x)
12:30	SagiCZ	emaczen: unlikely
12:31	SagiCZ	what editor do you use?
12:31	emaczen	emacs
12:31	justin_smith	SagiCZ: clojure.core is not referred if you use in-ns to create a namespace
12:31	emaczen	I'm user cider
12:31	justin_smith	emaczen: did you use in-ns to switch to a namespace that did not exist yet?
12:31	emaczen	justin_smith: I am switching namespaces
12:31	emaczen	I believe that it exists
12:31	justin_smith	how did you create the namespace?
12:32	justin_smith	I bet the ns code had an error, so the namespace was not created
12:32	justin_smith	just a guess
12:32	justin_smith	then when you used in-ns you created a namespace that did not have (refer-clojure)
12:32	emaczen	justin_smith: It does have an error -- I am editing it...
12:32	justin_smith	that's literally all you need to do to rescue your repl
12:32	justin_smith	(refer-clojure)
12:32	justin_smith	it's done implicitly by ns
12:34	emaczen	justin_smith: good to know, thanks
12:34	SagiCZ	in proxy macro how do i mimick super.method() call?
12:36	gfredericks	,(apropos "super")
12:36	clojurebot	(clojure.core/proxy-call-with-super clojure.core/proxy-super clojure.core/supers)
12:36	gfredericks	I'd check those first two
12:37	SagiCZ	it has no doc.. gosh i hate core
12:38	justin_smith	(doc proxy-super)
12:38	clojurebot	"([meth & args]); Use to call a superclass method in the body of a proxy method. Note, expansion captures 'this"
12:38	justin_smith	SagiCZ: ?
12:40	SagiCZ	proxy-call-with-super has no doc
12:40	justin_smith	it's a helper function used in implementing proxy-super
12:41	SagiCZ	i see.. well it at least works so thats nice
12:43	SagiCZ	i would like to use "this" in the proxy too..
12:44	justin_smith	SagiCZ: that's what proxy-super says - you can use "this" inside the body
12:44	justin_smith	as long as that is the name of the object in that scope, it will work
12:45	justin_smith	I don't like that it is a magic name used by the macro, but at least it's usable
12:45	justin_smith	you're just required to bind to the name "
12:45	SagiCZ	yeah.. that is super weird.. it works though
12:45	justin_smith	this" in the enclosing scope
12:45	justin_smith	right
12:54	devll	why I can't see the full deps tree with lein?
12:54	justin_smith	devll: is something missing from "lein deps :tree" ?
12:54	devll	I am having an issue with clj-http.
12:55	justin_smith	so what's wrong with the deps tree printing?
12:55	devll	I am using elastic search too which uses clj-http, but lein deps :tree does not show this.
12:56	justin_smith	devll: if it's not in the tree, how do you know the dep is present?
12:56	devll	I searched for the error
12:56	devll	then I got the info from github.
12:57	devll	I also verified from ClojureSphere
12:57	justin_smith	are they pulling in the dep via their declared deps, or resolving it and compiling it in when packaging?
12:57	devll	*it
12:59	justin_smith	devll: are you talking about elastich? their handling of the clj-http dep is super weird https://github.com/clojurewerkz/elastisch/blob/master/project.clj#L21
12:59	devll	yes.
13:00	justin_smith	devll: you can only have one version of a dep loaded. Likely clj-http is being loaded under another dep
13:00	justin_smith	if it's not present in the tree at all, that's seriously messed up
13:00	justin_smith	if you need a specific version, you should explicitly depend on that version rather than relying on transative deps
13:02	devll	in my case,deps tree are missing info.
13:02	justin_smith	can you post your deps tree output?
13:02	justin_smith	not in here, on refheap or something, of course
13:03	devll	ok
13:03	devll	wait for a minute
13:05	devll	http://pastebin.com/0in6rjmQ
13:06	justin_smith	devll: clj-http is right there, it's a top level dep
13:06	justin_smith	line 78, that's the version you have
13:08	devll	[clj-http "1.0.1-SNAPSHOT"]
13:08	justin_smith	snapshot gets translated into a date specific version
13:08	justin_smith	[clj-http "1.0.1-20140913.231842-1"] is what 1.0.1-SNAPSHOT gets today
13:09	justin_smith	that may change tomorrow
13:09	justin_smith	that's how snapshots work
13:09	devll	got it. lein deps :tree \| grep -i clj-http
13:09	devll	this only showed one line.
13:09	devll	my bad.
13:09	devll	thanks
13:10	justin_smith	no problem
13:16	SagiCZ	cfleming: any reason why cursive cant see my Java classes? the plugin itself can find them because it autoimported them but REPL says ClassNotFoudException when trying to load the clojure file
13:18	TEttinger	SagiCZ: loading a clojure file that itself imports java classes?
13:22	SagiCZ	yes
13:23	SagiCZ	clojure file with (:import (myPackage MyClass)
13:23	SagiCZ	fails
13:24	devll	WARNING: update already refers to: #'clojure.core/update in namespace: clj-http.client, being replaced by: #'clj-http.client/update
13:25	devll	I am getting this warning .
13:26	gfredericks	devll: hopefully newer versions of clj-http don't have that?
13:26	devll	what does this mean? how can I resolve this?
13:26	devll	I updated everything.
13:26	devll	no luck.
13:29	justin_smith	devll: someone needs to update clj-http to be compatible with clojure 1.7.
13:29	justin_smith	the warning doesn't mean anything is broken though
13:29	justin_smith	it just means they gave something the same top level name as something in clojure.core
13:29	AlwaysBCoding	does anyone know what \_ means as a character in Clojure? It’s coming from an api where a &nbsp was in a string and the string in clojure just has a weird _ character in it. When I do (seq (char-array string)) it shows up as \_ … what is that character and how could I regex it out?
13:30	justin_smith	,(type \_)
13:30	clojurebot	java.lang.Character
13:30	SagiCZ	AlwaysBCoding: its a clojure literal for the underscore symbol "_"
13:30	justin_smith	oh, that may be something different
13:30	devll	I cant use clj-http. it eventually throws an error.
13:30	justin_smith	,(int \_)
13:30	clojurebot	95
13:31	justin_smith	AlwaysBCoding: that's a normal underscore - is that copy pasted from the original?
13:31	the-kenny	devll: that warning isn't a big issue. It just says you import a function named 'update' which overrides the clojure function with the same name.
13:31	justin_smith	AlwaysBCoding: use int to find out it's numerical value, that will be unambiguous
13:31	devll	- Attempting to call unbound fn: #'clj-http.client/update
13:31	AlwaysBCoding	it shows up in emacs/cider as a yellow underscore, but if I regex on an underscore it doesn’t match
13:32	godd2	,(str \h \e \l \l \o)
13:32	clojurebot	"hello"
13:32	the-kenny	devll: Either import qualified [... :as http] or refer only the functions you need: [... :refer [fn1 fn2 ...]]
13:32	devll	I got this error too.
13:32	the-kenny	AlwaysBCoding: \_ is a char, not a string.
13:32	justin_smith	AlwaysBCoding: OK, in the context where you have that string, map int across the string
13:32	the-kenny	,(first "_")
13:32	clojurebot	\_
13:32	justin_smith	AlwaysBCoding: get the actual code point
13:32	devll	I delete all the (:use ) today.
13:32	devll	deleted*
13:32	AlwaysBCoding	int value is 160
13:33	justin_smith	devll: I think that has to do with the fact that your libs require like 80 different versions of clj-http
13:33	devll	I exclude all
13:33	justin_smith	devll: likely the one you are providing does not define the function one of your libs needs
13:33	devll	d
13:33	justin_smith	devll: exclude does not help when they call a function not defined in the version of the lib you pull in
13:33	justin_smith	that's the problem
13:33	devll	I downgraded Clojure to 1.6.0
13:33	devll	then it is OK.
13:33	justin_smith	devll: that won't fix your probelm
13:34	justin_smith	really?
13:34	justin_smith	...
13:34	devll	yes.
13:34	the-kenny	justin_smith: 1.6 doesn't have clojure.core/update
13:34	the-kenny	only clojure.core/update-in
13:34	AlwaysBCoding	the int value of a normal underscore is 95 it seems, then what the hell is 160? wtf haha this is tripping me out
13:34	justin_smith	the-kenny: his actual problem is something in his code calls clj-http/update and it does not exist
13:34	godd2	AlwaysBCoding the \ is used to denote a single character. So "h" and \h are pretty much the same thing, as are "_" and \_
13:34	justin_smith	godd2: but not everything that prints as _ is _
13:35	justin_smith	AlwaysBCoding: unicode 160 is non breaking space http://www.fileformat.info/info/unicode/char/00a0/index.htm
13:35	justin_smith	that's your issue
13:35	justin_smith	&nbsp translates to that unicode symbol
13:35	lazybot	java.lang.RuntimeException: Unable to resolve symbol: nbsp in this context
13:35	justin_smith	lazybot: shutup
13:36	AlwaysBCoding	justin_smith: awesome. how can I regex out that character from strings?
13:37	justin_smith	AlwaysBCoding: I'd use clojure.string/replace to replace nbsp with regular space maybe
13:38	godd2	does \s not match nbsp?
13:39	godd2	or refer to it by its unicode \u00a0
13:39	AlwaysBCoding	justim_smith: how though? like it doesn’t match &nbsp or anything
13:39	justin_smith	AlwaysBCoding: looks like godd2 is on the right track there
13:39	AlwaysBCoding	ok got it. It looks like it matches if you do '\xa0'
13:39	the-kenny	doesn't clojure.string/replace also work on char/char replacements? Just specify nbsp as second arg, space as third.
13:40	AlwaysBCoding	godd2: \u00a0 works also, awesome
13:40	godd2	coolio
13:43	justin_smith	/me loves it when a plan comes together.
13:44	justin_smith	great work, team!
13:46	godd2	(synergize [:team_member1 :team_member_2 :team_member_3 :team_member_4])
14:12	erik``	why does
14:12	slipset	,(+)
14:12	clojurebot	0
14:12	slipset	but not
14:12	slipset	,(-)
14:12	clojurebot	#<ArityException clojure.lang.ArityException: Wrong number of args (0) passed to: core/->
14:13	justin_smith	,(/ 2)
14:13	clojurebot	1/2
14:13	slipset	and one could expect
14:13	godd2	slipset subtraction doesnt have a left-associative identity
14:13	slipset	ah!
14:14	justin_smith	godd2: well, it won't until we invent anti-zero
14:14	slipset	So then there might be a (good) reason why
14:14	slipset	,(max)
14:14	clojurebot	#<ArityException clojure.lang.ArityException: Wrong number of args (0) passed to: core/max>
14:15	justin_smith	,(min)
14:15	clojurebot	#<ArityException clojure.lang.ArityException: Wrong number of args (0) passed to: core/min>
14:15	justin_smith	,(*)
14:15	clojurebot	1
14:15	slipset	one could imagine (max) return something very small :)
14:16	godd2	slipset think about what reduce does
14:16	slipset	godd2, that's actually what I'm trying to think about
14:16	slipset	(reduce max [1 23 8 2 ])
14:17	justin_smith	,(max Double/NEGATIVE_INFINITY)
14:17	clojurebot	-Infinity
14:17	hyPiRion	,(reduce max []) ;; ???
14:17	lazybot	hyPiRion: Oh, absolutely.
14:17	clojurebot	#<ArityException clojure.lang.ArityException: Wrong number of args (0) passed to: core/max>
14:17	slipset	(reduce and [])
14:17	slipset	,(reduce and [])
14:17	clojurebot	#<CompilerException java.lang.RuntimeException: Can't take value of a macro: #'clojure.core/and, compiling:(NO_SOURCE_PATH:0:0)>
14:17	slipset	d'oh!
14:18	slipset	,(and)
14:18	clojurebot	true
14:18	hyPiRion	and is a monoid though
14:18	godd2	the identity of addition is 0, so reducing [1 2 3] is (+ (+ (+ 0 1) 2 ) 3), but for subtraction, (- 1 2) doesnt equal (- (- 0 1) 2)
14:18	slipset	,(or)
14:18	clojurebot	nil
14:18	hyPiRion	max and min aren't
14:18	justin_smith	godd2: right, which is why I suggested we need anti-0
14:18	slipset	hyPirion: max and min aren't monoids, or aren't monoids in Clojure?
14:19	slipset	I only do crud
14:19	godd2	justin_smith but then we'd have to prove uniquness and that all just too much hassle
14:19	justin_smith	godd2: why prove something when you can axiomize it?
14:19	justin_smith	"the value that is the left-associative identity for subtraction"
14:20	justin_smith	done, it's unique
14:20	hyPiRion	slipset: They could be monoids for floating point values, but not for any other numeric type
14:20	godd2	justin_smith I think you may run into a contradiction from commutativity.
14:20	hyPiRion	Well, I mean, they could be for any type, but I'm not sure if it makes sense
14:21	justin_smith	godd2: oh god
14:21	justin_smith	right
14:21	slipset	hyPirion: the question sortof arises from one of @ctfords tweets this evening.
14:21	slipset	he had a function somewhat like
14:21	justin_smith	godd2: hrm, wait - no - it would be similar to i I think
14:21	godd2	justin_smith you might be right, I'm just speculating
14:21	justin_smith	godd2: it introduces a new kind of "complex number" anti-zero+n
14:21	slipset	(defn f [l] (->> :foo (max)))
14:22	slipset	(defn f [l] (->> l :foo (max)))
14:22	slipset	it should be
14:22	godd2	justin_smith and the anti-identity matrix
14:22	slipset	which fails when the list he passes in is empty
14:22	justin_smith	right, right
14:22	slipset	sorry, my brain is not on
14:22	slipset	(defn f [l] (->> l (map :foo) (max)))
14:23	hyPiRion	slipset: I think you forgot a reduce or apply there
14:23	justin_smith	yeah, definitely forgot an apply
14:23	hyPiRion	(->> l (map :foo) (reduce max))
14:23	slipset	hyPirion: you're right
14:23	slipset	(defn f [l] (->> l (map :foo) (apply max)))
14:23	slipset	but this fails when the list is empty
14:23	slipset	since max is not a monoid
14:23	slipset	but
14:24	slipset	(defn f [l] (->> l (map :foo) (reduce 0 max)))
14:24	slipset	works
14:24	slipset	as would wrapping the whole thing in a (if ...)
14:24	hyPiRion	slipset: sure, but that assumes the lowest value in the list is 0
14:24	justin_smith	slipset: that works if at least one arg is positive
14:25	slipset	which I guess is a pre-condition to this function
14:25	justin_smith	slipset: use Double/NEGATIVE_INFINITY instead maybe?
14:25	justin_smith	or just not provide an anitial value and let reduce use the first value as the inditial
14:25	hyPiRion	Actually, I just retract my statement about max/min being monoids. They simply can't be.
14:25	hyPiRion	,(max Double/NaN Double/POSITIVE_INFINITY)
14:25	clojurebot	NaN
14:25	slipset	justin_smith: sure, in the general case, but in this specific case, 0 is known to be the smallest possible value
14:26	hyPiRion	,(= Double/NaN Double/NaN)
14:26	clojurebot	false
14:26	justin_smith	slipset: why not use the general solution?
14:27	slipset	justin_smith: I guess if it were my code, I'd wrap the thing in a (if (seq l) ... 0)
14:27	emaczen	What is the difference between atoms and agents? All I can tell is that they both are asynchronous.
14:28	justin_smith	emaczen: agents don't retry, for one
14:28	justin_smith	and they have a queue, rather than speculative execution
14:29	emaczen	So an agent seems more like the traditional asynchronous execution that I would think of.
14:29	slipset	would it be correct to say that you send someting off to an agent to happen at some time, whereas a change to an atom happens quite immediatly?
14:29	justin_smith	emaczen: if you know contention will be low (the normal case) an atom will be faster. If you know it will be high (or if retries would be disasterous) agents are definitely better.
14:30	justin_smith	slipset: change to an atom happens when it is done with the computation you use, plus all relevant retries (if any)
14:30	slipset	justin_smith: and while updating an atom you block, right?
14:31	emaczen	justin_smith: can you define or point me to contention?
14:31	slipset	whereas updating an agent is non blocking.
14:31	slipset	?
14:31	justin_smith	emaczen: two overlapping updates to the same atom
14:31	justin_smith	something else changed it while you were using it
14:32	emaczen	justin_smith: cool!
14:32	justin_smith	swap! will restart with the new value, if any change happened after it started and before it commited
14:32	justin_smith	which is why swap! + side effects is bad news
14:37	justin_smith	emaczen: oh, another big difference is that if you get an exception when doing a swap! on an atom, you get it in your calling context, but an exception on a send or send-off to an agent will be handled by the agent's exception handler (or via explicit calls to agent-error and restart-agent later)
14:39	emaczen	Is retrying by the atom the major difference? It makes sense to me to use agents over atoms when contention is high due to the retrying.
14:39	justin_smith	atoms have less coordination overhead, and you can deal with exceptions / get the result transperently in the calling context
14:56	gfredericks	emaczen: I think switching to agents due to contention only makes sense if the contention is due to the update function being slow
14:56	gfredericks	threads still have to contend to get stuff into the agent's queue
14:57	justin_smith	gfredericks: isn't it a decent sized queue though? and queue insertion should't be a wide target for contention
14:58	gfredericks	I wasn't referring to queue size just the coordinated operation
14:58	justin_smith	aha, yeah
14:58	gfredericks	what do they use some kind of j.u.c.QueueThinger?
15:00	justin_smith	gfredericks: https://github.com/clojure/clojure/blob/clojure-1.6.0/src/jvm/clojure/lang/Agent.java#L24
15:00	gfredericks	an AtomicReference to an ActionQueue
15:00	justin_smith	yup
15:01	gfredericks	what on earth is line 40 about?
15:01	gfredericks	is that an initial value for an instance variable?
15:01	emaczen	doc isn't working in the "user" namespace for me, what is going on?
15:01	justin_smith	emaczen: (use 'clojure.repl)
15:02	gfredericks	emaczen: dunno that's complicated, I recommend using lein-shorthand and not investigating further :)
15:02	justin_smith	emaczen: likely lein added clojure.repl to your "main ns", whichever that is
15:02	emaczen	use is the same as require right?
15:03	justin_smith	gfredericks: it's declaring an instance field on Agent, with some misleading indentation
15:04	justin_smith	emaczen: kind of, it's the same as (require 'foo :refer :all)
15:04	emaczen	I'm looking for a function like common-lisps make-list or make-array where you can specify the number of entries to be in the sequence and the initial argument.
15:04	justin_smith	emaczen: checkout conj.io
15:04	emaczen	justin_smith: Ok, so you can pick a subset of the stuff that you want to import
15:04	emaczen	what is conj.io?
15:05	gfredericks	justin_smith: I didn't think instance fields could have initial values set at the top level
15:05	gfredericks	like
15:05	gfredericks	what does that even?
15:05	justin_smith	emaczen: a cheatsheet of useful clojure functions
15:05	gfredericks	I'm gonna go write some java code to try this out.
15:05	justin_smith	gfredericks: ahh, good point
15:06	emaczen	justin_smith: is conj.io as website or something?
15:06	justin_smith	emaczen: anyway, the function you want is on conj.io, and is called repeatedly
15:06	justin_smith	emaczen: yes
15:06	emaczen	I'm googling it, and not finding anything
15:06	justin_smith	http://conj.io
15:06	justin_smith	,(repeatedly 3 :a)
15:06	justin_smith	err
15:06	clojurebot	#<IllegalArgumentException java.lang.IllegalArgumentException: Wrong number of args passed to keyword: :a>
15:06	justin_smith	sorry
15:06	justin_smith	,(repeat 3 :a)
15:06	clojurebot	(:a :a :a)
15:06	justin_smith	much better
15:07	justin_smith	emaczen: http://conj.io/store/v0/org.clojure/clojure/1.7.0-alpha4/clj/clojure.core/repeat/
15:08	justin_smith	emaczen: anyway, most of the interesting functions in clojure are on that page (http://conj.io aka grimoire), and it is updated pretty regularly
15:08	emaczen	sweet! Thanks for the resource
15:09	emaczen	Can you get a vector instead of a list from repeat?
15:09	gfredericks	justin_smith: looks like java lets you do it and just runs the expression every time you initialize something
15:09	justin_smith	gfredericks: so it's like constructor code that is not inside the constructor
15:09	TEttinger	emaczen, sure
15:10	TEttinger	,(vec (repeat 5 "whee"))
15:10	clojurebot	["whee" "whee" "whee" "whee" "whee"]
15:10	TEttinger	sorry, didn't realize that nick was in use
15:10	emaczen	hah okay thanks TEttinger -- I thought it might have been a keyword argument to repeat
15:10	TEttinger	that's rare in clojure, usually things return seqs
15:10	gfredericks	justin_smith: yep I believe so.
15:11	gfredericks	I'll check whether it runs before or after constructor.
15:11	gfredericks	runs before
15:11	gfredericks	TIL about java.
15:11	justin_smith	~java
15:11	clojurebot	java is a mutable basket case
15:11	justin_smith	~clojure
15:11	clojurebot	clojure is the bestest programming language available.
15:11	gfredericks	~a mutable basket case
15:11	clojurebot	excusez-moi
15:24	justin_smith	~java
15:24	clojurebot	java is nuts
15:24	justin_smith	more of that mental illness theme, I see
15:24	justin_smith	~nuts
15:24	clojurebot	excusez-moi
15:25	justin_smith	from a pm: 12:24 <clojurebot> ☕
15:29	crazydiamond	Hi. Is there "loop version" of walk/postwalk?
15:29	TEttinger	(identity justin_smith)
15:29	lazybot	justin_smith has karma 200.
15:29	TEttinger	gasp!
15:29	TEttinger	you reached it justin_smith!
15:29	justin_smith	I couldn't have done it without the help of all the little people
15:29	TEttinger	haha
15:29	justin_smith	meaning the leprechauns who help me answer clojure questions
15:30	justin_smith	it's a great day in fake internet points for me, to be sure
15:31	justin_smith	let's just hope technomancy doesn't figure out I was stealing his points while he wasn't looking
15:31	justin_smith	(identity technomancy)
15:31	lazybot	technomancy has karma 162.
15:33	justin_smith	woah, does anyone else see a "run code snippet" button on this? http://stackoverflow.com/questions/28786376/how-can-i-use-a-unsigned-64-bits-variables-in-bits-operations-in-clojure
15:34	gfredericks	yep
15:34	justin_smith	I have never seen that feature before
15:34	gfredericks	I clicked it and it just printed the code
15:34	justin_smith	it appears to be totally broken
15:34	gfredericks	unformatted
15:34	justin_smith	but it looks like a new feature
15:35	justin_smith	perhaps it will even work soon, that would be cool
15:35	gfredericks	maybe it assumes all code is a language wherewithin everything evaluates to itself
15:35	gfredericks	or rather itself without newlines and in a variable-width font
15:36	justin_smith	reminds me of this messed up language I tried once called html
15:37	kryft	Hmm, I tried to set :friend/redirect-on-auth? to false, but I still seem to get redirection upon successful login
15:38	TEttinger	justin_smith: gfredericks: it looks like that code snippet doesn't have highlighting, maybe they didn't set the language
15:38	justin_smith	aha, I will edit it!
15:38	kryft	If I have (:require [cemerick.friend :as friend]), then :friend/redirect-on-auth? should be the same symbol as ::redirect-on-auth? in the cemerick.friend ns, right?
15:38	justin_smith	TEttinger: oh, I reloaded, someone else set the language
15:39	Bronsa	kryft: ::friend/redirect-on-auth
15:39	justin_smith	TEttinger: maybe it was a java related feature? (or chess or bitboard...)
15:39	TEttinger	haha
15:39	kryft	Bronsa: ...ah, thanks
15:39	justin_smith	TEttinger: ahh! the button was there because it had been set as lang-html http://stackoverflow.com/posts/28786376/revisions
15:39	kryft	So :friend/redirect-on-auth would be ::my-current-ns/friend/redirect-on-auth :P
15:39	justin_smith	and they switched it to java which is way silly
15:40	Bronsa	kryft: no :friend/redirect-on-auth is just :friend/redirect-on-auth
15:41	kryft	Bronsa: Ok, I'd better reread the docs on that, thanks :)
16:54	lvh	is there a shorthand for "apply, except for macros"?
16:55	lvh	E.g. if I have a list [1 2 3 4], I want to be able to easily do (are [whatever] some-expr ~@that-list) in a test
16:55	lvh	except without the ~@ I guess
16:56	justin_smith	lvh: I think it would need to be another macro
16:57	lvh	justin_smith: Indeed it would; I was hoping that'd be a macro someone already wrote ;)
16:57	justin_smith	actually, it may be hard to do without eval...
16:57	arohner	lvh: there's apply-macro floating around
16:58	justin_smith	https://github.com/clojure/clojure-contrib/blob/73accf597eafb8dfcb642702a3b98b057bbdbbdf/src/main/clojure/clojure/contrib/apply_macro.clj#L34
16:58	arohner	lvh: I'm on slow internets right now, you'll have to google for it. It was in old contrib, not sure if it got re-released
16:58	justin_smith	like I thought, eval :(
16:58	lvh	arohner: Found it; thanks :)
16:58	arohner	lvh: but I'd be cautious about using it. It's not really idiomatic
16:58	arohner	and ~@ works just fine in most cases
16:58	justin_smith	"This is evil. Don't ever use it. It makes a macro behave like a function. Seriously, how messed up is that?"
16:58	lvh	heh
16:58	arohner	`(are [whatever] some-expr ~@that-list)
16:59	lvh	Yeah :-)
16:59	lvh	I might also just use is and give up on are's magic
17:00	lvh	maybe that's slightly suboptimal because I'll get pretty terrible error message out when a test fails
17:13	hq1	hi, noob here. I'm having trouble getting cljfmt to work. `lein cljfmt check src/foo/core.clj` works, but I'm having classpath issues when running `lein repl` and trying to (require `cljfmt.core) throws FileNotFoundException. My lein version is 2.5.1. Profile: https://gist.github.com/aerosol/2b2da25ec3bf72f21d59
17:15	hq1	Running `lein classpath` doesn't include any of the cljfmt packages. Is that supposed to be handled automatically or do I need some extra configuration?
17:16	arohner	hq1: that's a lein profile issue
17:17	hq1	as in, the profile is misconfigured?
17:17	arohner	if you try to require at runtime, it needs to be in the standard deps. I'm assuming cljfmt, when loaded as a plugin, puts itself in the :dev profile
17:18	hq1	oh ok, let me look that up
17:20	arohner	hq1: :plugins are code that is loaded into the lein process. :dependencies are loaded into your app's process. Some plugins add dependencies.
17:21	arohner	hq1: lein-cljfmt is the lein plugin. [cljfmt "0.1.7"]. is the runtime code. I bet lein-cljfmt adds cljfmt as a dependency. If you don't go through that path, cljfmt doesn't get loaded, and you can't require from repl
17:22	arohner	so the way to fix it is just add [cljfmt "0.1.7"] as a dependency. You probably want to put it in your :dev profile, like {:profiles {:dev {:dependencies [[cljfmt "0.1.7"]]...
17:22	hq1	thanks arohner
17:24	emaczen	can someone here help me with cider? #clojure-emacs is very quiet
17:24	hq1	arohner: brilliant, it works as expected now.
17:24	arohner	~ask
17:25	clojurebot	The Ask To Ask protocol wastes more bandwidth than any version of the Ask protocol, so just ask your question.
17:25	emaczen	when I start a cider-repl, I am now seening warnings
17:25	emaczen	1) WARNING: CIDER requires nREPL 0.2.7 to work properly
17:25	emaczen	2) WARNING: The following required nREPL ops are not supported:
17:25	emaczen	apropos classpath complete eldoc format-code format-edn info
17:25	emaczen	inspect-start inspect-refresh inspect-pop inspect-push inspect-reset
17:25	emaczen	macroexpand ns-list ns-vars resource stacktrace toggle-trace-var
17:25	emaczen	toggle-trace-ns undef
17:25	emaczen	Please, install (or update) cider-nrepl 0.9.0-SNAPSHOT and restart
17:25	emaczen	CIDER
17:26	emaczen	WARNING: CIDER's version (0.9.0-snapshot) does not match
17:26	emaczen	cider-nrepl's version (not installed)
17:26	scottj	uh oh
17:26	emaczen	All I did was install cider via MELPA
17:26	justin_smith	emaczen: what it is saying is that your clojure process needs a cider-nrepl dep to work properly with cider
17:27	justin_smith	emaczen: the two halves are distributed and installed separately, but their versions must match
17:27	emaczen	justin_smith: where do I get this nrepl plugin?
17:27	justin_smith	usually it will be installed via a plugin in profiles.clj
17:27	emaczen	justin_smith: can I put it in project.clj?
17:27	justin_smith	emaczen: declare a dep for cider-nrepl with the version string it asks for under the dev profile
17:28	justin_smith	it's better off in ~/.lein/profiles.clj unless you only plan to use cider with one project
17:29	arohner	emaczen: putting it in project.clj is good if you're planning on starting nrepl at runtime, i.e. in production. Otherwise put it in profiles
17:30	emaczen	thanks guys!
17:33	emaczen	So I am still getting some warning messages that aren't clear to me
17:34	emaczen	WARNING: CIDER requires nREPL 0.2.7 to work properly
17:34	emaczen	{:user {:plugins [[cider/cider-nrepl "0.8.2"]]}} -- I put this in profiles.clj
17:34	justin_smith	why did you pick that version?
17:34	justin_smith	the error message told you exactly the version it wanted
17:35	emaczen	That's the version which is in Melpa
17:35	emaczen	cider 0.8.2 installed Clojure Integrated Development Environment and REPL
17:35	justin_smith	emaczen: something's fucky
17:35	justin_smith	your cider thinks it is 0.9.0-SNAPSHOT
17:36	justin_smith	and that's the version of cider-nrepl it is asking for
17:36	emaczen	what is the difference between the two warnings:
17:36	emaczen	WARNING: CIDER requires nREPL 0.2.7 to work properly
17:36	emaczen	WARNING: CIDER's version (0.9.0-snapshot) does not match cider-nrepl's version (0.8.2)
17:36	emaczen	I also get the 0.9.0-SNAPSHOT warning
17:36	arohner	emaczen: I bet you have multiple cider.el's loaded in emacs
17:36	justin_smith	nrepl is a dep that cider-nrepl needs
17:36	emaczen	arohner: That's probably valid -- I'll remove them and then restart emeacs
17:37	justin_smith	the version of nrepl, and the version of cider-nrepl, are both not usable by your version of cider
17:37	justin_smith	~cider
17:37	clojurebot	cider is Try #clojure-emacs for more help with Cider
17:37	justin_smith	~cider
17:37	clojurebot	cider is Cider is unstable and broken right now, most things don't work. Use the last stable version of nrepl.el for now.
17:39	emaczen	arohner: AMAZING! It works! FINALLY!
17:40	arohner	emaczen: great!
17:40	emaczen	arohner: Now I will play with company-mode and the extra jazz :)
17:40	emaczen	is there a recommended way to reload your .emacs file?
17:41	emaczen	I either M-x eval-buffer or M-x load-file [.emacs]
17:41	arohner	not that I know of. The bigger problem is there isn't a convenient way to unload the effects of an old file
17:42	emaczen	Yeah ...
17:42	justin_smith	if only we had component.el
17:42	justin_smith	haha
17:49	gfredericks	has anybody written clojure.el yet?
17:51	emaczen	what do you guys use for clojure completion?
17:51	gfredericks	something terrible
17:54	scottj	gfredericks: have you seen dash.el?
17:55	gfredericks	yeah
17:59	avshalom	emaczen: company
18:00	emaczen	avshalom: do you know of a way to rebind the up and down arrow keys for selection of a completion in the scroll bar?
18:01	avshalom	emaczen: not sure how to do that. are you talking about company mode?
18:18	emaczen	avshalom: I figured it out if you want the code
18:19	chipf0rk	Hi, could anyone familiar with cider/cider-nrepl help me out? I've upgraded cider in emacs to the latest version and the cider-nrepl version in my profiles.clj is 0.9.0-SNAPSHOT, but cider seems to think it's both 0.9.0snapshot and 0.8.1 at the same time...
18:20	emaczen	chipf0rk: I might have just had this problem
18:20	chipf0rk	WARNING: CIDER's version (0.8.1) does not match cider-nrepl's version (0.9.0)-snapshot) - yet it says "CIDER 0.9.0snapshot" one line above
18:20	emaczen	You may have multiple versions of cider loaded into emacs
18:20	emaczen	I just rebooted
18:20	emaczen	and it was fine
18:20	chipf0rk	rebooted or restarted emacs?
18:20	chipf0rk	because I've tried the latter
18:20	emaczen	restarted emacs
18:21	emaczen	the lateset in elpa is 0.8.2 for me
18:23	chipf0rk	hold up, `killall emacs` might've done the trick
18:23	chipf0rk	sigh
18:23	clojurebot	Excuse me?
18:25	chipf0rk	"CIDER 0.9.0snapshot (package: 20150228.1306)" btw
18:25	chipf0rk	so 0.9.0snapshot seems to be in my package repos
18:26	emaczen	it has to match what is in profiles.clj
18:26	chipf0rk	I'm aware of that
18:26	emaczen	why not use 0.8.2
18:27	chipf0rk	good question - mainly because I saw that I had emacs upgrade to 0.9.0
18:27	chipf0rk	how do I downgrade a package?
18:27	maveneagle	hi guys, I was trying to understand the reducers in clojure. Just wanted to know if i understand it correctly.. when i create a reducer for map and reduce it, the specific collection (vec, list et all) will reduce itself "sequentially"? but the same reducer if i try to fold it will use the fork/join approach to parallelise the reduction?
18:27	chipf0rk	to a specific version
18:27	Zardoz	So ~/.lein/profiles.clj has the right plugin version?
18:27	chipf0rk	welp it has 0.9.0-SNAPSHOT atm
18:27	emaczen	So 20150228 in my packages buffer is from melpa
18:28	emaczen	Usually there is a melpa archive and a marmalade archive
18:28	emaczen	the marmalade archive lists the version and the latest for cider was 0.8.2
18:28	emaczen	unless it changed in the last 30 minutes
18:29	chipf0rk	i'm reinstalling the cider package I guess
18:29	Zardoz	Can confirm, mine is "20150228"
18:34	arohner	maveneagle: I don't think reducers specify an order. in fact I think they explicitly don't
18:34	arohner	maveneagle: though transducers are explicitly fold-left
18:34	chipf0rk	well that's interesting, it installed the same version, now that warning's gone
18:35	chipf0rk	however it now tells me it needs nrepl 0.2.7
18:35	arohner	maveneagle: there's also https://github.com/aphyr/tesser
18:35	Zardoz	Oh yeah, that's annoying
18:36	Zardoz	Make sure your profiles.clj looks like this:
18:36	Zardoz	{:user {:plugins [[cider/cider-nrepl "0.9.0-SNAPSHOT"]]
18:36	Zardoz	:dependencies [[org.clojure/tools.nrepl "0.2.7"]]}}
18:36	emaczen	chipf0rk: I had the exact same errors before but the restart just worked for me
18:36	chipf0rk	doesn't for me sadly :(
18:36	chipf0rk	hold on I can specify deps in profiles.clj? oh
18:37	emaczen	Can anyone link me to a resource about OO design and clojure? I'm seeing a lot about just using values and datastructures (I like the idea of just using a map everywhere but I want to see the other options as well)
18:39	maveneagle	arohner: thanks, will have a look at it
18:39	chipf0rk	Zardoz: Seems to have done the trick. Thanks a bunch!
18:39	Zardoz	You're welcome =D
18:40	Zardoz	I ran into the same thing last week
18:47	justin_smith	emaczen: regarding when to use maps etc. http://cemerick.com/2011/07/05/flowchart-for-choosing-the-right-clojure-type-definition-form/
18:47	justin_smith	emaczen: you won't be let down by that flowchart
18:49	justin_smith	emaczen: regarding OO, OO in clojure is mostly about keeping things modular by definining functions that work on interfaces / protocols, and then extending those interfaces / protocols to the types you need (starting with the persistent datatypes like map, vector, list, set etc.)
18:50	justin_smith	also see multimethods, and derive, between those you can do some interesting OO things
18:50	emaczen	justim_smith: cool, I am somewhat familiar with multi-methods but not derive
18:50	justin_smith	emaczen: multimethods respect the heirarchies created via derive for dispatch
18:51	justin_smith	finally, information hiding isn't as important when your data is not mutable
18:53	emaczen	justin_smith: What can you tell me about lazy evaluation?
18:53	justin_smith	what about it?
18:53	emaczen	I think I have a good question that will clarify my understanding thus far for you.
18:55	emaczen	If I have a nested map expression, in common-lisp it must finish evaluating the nested map expression before the outer-expression can be evaluated
18:55	justin_smith	emaczen: clojure lazy-sequences are always evaluated in order
18:56	justin_smith	but they are not always realized
18:56	emaczen	I thought in Clojure, the outer sequence would begin to be evaluated as soon as the inner one had "returned" an element
18:57	justin_smith	emaczen: it really depends. I'm putting together an example.
18:59	justin_smith	contrived example:
18:59	justin_smith	,,(let [counter (atom 0)] (nth (map (fn [i] (map #(swap! counter + %) (take 3 (repeat 1)))) (iterate inc 0)) 1000))
18:59	clojurebot	(1 2 3)
19:00	justin_smith	emaczen: notice that I get the 1000th element from the outer map
19:00	justin_smith	but the inner map is the first of the inner maps to be realized
19:00	justin_smith	the rest, being lazy, have not been generated yet, because they were not accessed
19:06	emaczen	justin_smith: I don't know enough clojure yet to follow it to a tee -- but what I think you are getting at is that the nested-maps will only evaluate till they get the 1000th item. Is that right?
19:07	justin_smith	emaczen: (iterate inc 0) gets the integers starting with 0
19:07	justin_smith	,(iterate inc 0)
19:07	clojurebot	(0 1 2 3 4 ...)
19:08	justin_smith	actually - let me simplify it, one moment
19:10	justin_smith	,(let [counter (atom 0)] (last (repeatedly 1000 (fn [] (map #(swap! counter + %) (repeat 3 1))))))
19:10	clojurebot	(1 2 3)
19:10	justin_smith	that's equivalent, and hopefully easier to read
19:10	justin_smith	so, it's a lazy seq of evaluating that function 1000 times
19:10	justin_smith	and we are just taking the last item and returning it
19:11	justin_smith	the item is generated by mapping an increment of the atom across [1 1 1]
19:11	justin_smith	in fact I should have written [1 1 1] instead of (repeat 3 1)
19:12	justin_smith	what's to be noted, is that for each realized element of that 1000 item sequence, the atom is incremented 3 times
19:12	maveneagle	I was watching Rich hickey's talk on reducers, I just want to understand how this line performs efficient compared to the old map & reduce -> (time (reduce + (r/map inc (r/filter even? v))))
19:12	justin_smith	but you see at the end, it only got incremented 3 times total, even though we got to the 1000th item
19:12	maveneagle	i do understand fold is optimsed due to fork join
19:13	emaczen	what is the %?
19:14	justin_smith	emaczen: oh, that's a shortcut for anonymous functions
19:14	justin_smith	,'#(+ % %)
19:14	clojurebot	(fn* [p1__54#] (+ p1__54# p1__54#))
19:14	emaczen	it looks like a placeholder
19:14	justin_smith	it just means "first argument"
19:16	emaczen	so why aren't all the elements "realized"
19:16	justin_smith	emaczen: they are lazy, and were not accessed
19:16	justin_smith	which is why typically you really want referentially transperent functions generating lazy sequences
19:17	justin_smith	I intentionally made a contrived, non-transperent function (closing over the mutable atom) to demonstrate the behavior
19:18	emaczen	Yeah, I would think the values would be 2998 2999 3000
19:18	emaczen	If you count from 1
19:19	emaczen	Which you aren't so subtract 1 from what I wrote above
19:19	justin_smith	the first swap! returns 1
19:19	justin_smith	so it does count from 1
19:19	emaczen	oh ha
19:19	justin_smith	swap! returns the new value, and you added 1
19:20	justin_smith	well, not you, but anyway
19:20	emaczen	Can you tell me what happends under the hood? A contrived example is just telling me that the first portion of the list is not evaluated?
19:20	justin_smith	under the hood a lazy seq is a thunk
19:21	emaczen	thunk?
19:21	justin_smith	a function of no arguments returning the next element of the list
19:21	justin_smith	or, actually, returning a next element, followed by a "rest" that is a thunk
19:21	justin_smith	which is in turn the same
19:21	justin_smith	until one of them has an empty rest
19:25	emaczen	justim_smith: It would probably be very educational to play with a thunk -- I've done this before in scheme. I'll have to look into it again but more in depth
19:26	justin_smith	emaczen: thunks are just how lazy-seqs are implemented
19:26	justin_smith	typically you don't need to use them directly
19:26	justin_smith	though we have delay, for doing similar things with explicit deref
19:26	emaczen	I just remember using "force" or something in scheme
19:26	emaczen	To actually get the next element
19:31	emaczen	justin_smith: Isn't the implementation of lazy sequences a starting value and a function to get you the next element?
19:31	justin_smith	a function that gets you next element and next function
19:31	emaczen	And when you actually want to get the next value, you just apply this function with the current value?
19:31	justin_smith	because that first function can only give you the first element
19:32	justin_smith	no
19:32	justin_smith	you get a new lazy-seq at each step
19:32	justin_smith	or nil (empty)
19:46	maveneagle	why is the second line faster than the second line here (https://gist.github.com/anonymous/19702a4efdac2cedae97) I understand why the 3rd line is faster though
19:47	maveneagle	* second line faster than first line
19:47	justin_smith	maveneagle: lazy-seqs have an overhead that r/map and r/filter do not
19:48	maveneagle	justin_smith: ahh.. thanks! forgot about that
19:48	justin_smith	maveneagle: as I was just describing to emaczen, the thunk created for each item
19:48	justin_smith	maveneagle: r/map does not need to create that for each element
19:49	bbloom	gfredericks: i think i solved my irc time traveling problem
19:50	justin_smith	maveneagle: for more info, you would likely find it informative to look at transducers. They solve a similar performance problem in a more generalized way.
19:50	gfredericks	bbloom: omg omg omg
19:50	bbloom	gfredericks: solution was to switch ISPs by moving across the country
19:50	gfredericks	bbloom: oh right of course
19:50	gfredericks	obvious in hindsight
19:50	maveneagle	justin_smith: sure, I am gonna watch rich's talk on transducers
19:50	justin_smith	maveneagle: whereas reducers specialize map, filter, etc. for reduce, transducers generalize them to be efficiently used for any source / sink of data generally
19:51	bbloom	gfredericks: if i start time traveling again, you let me know so that i can move back before i test another solution. we want to be scientific about this
19:52	gfredericks	bbloom: I bet if you had called the IRC call center they would've made you try that before anything else
19:52	justin_smith	bbloom: my guess was that you were in a weird spot in respect to the infrastructure of the Internet that would cause you to be separated in multi-jump netsplits from most of us
19:52	bbloom	i always refuse to unplug it and plug it back in again
19:53	gfredericks	~bbloom is in a weird spot in respect to the infrastructure of the Internet
19:53	clojurebot	A nod, you know, is as good as a wink to a blind horse.
19:53	enn	So Clojure Autodoc, Marginalia, and Codox all generate fairly fancy multi-column layouts for the documention. Can anyone recomment a tool that generates something more basic?
19:54	emaczen	in core.match, can a pattern be a predicate? I'm pretty sure I've seen this functionality in elisp's pcase.
19:55	bbloom	emaczen: https://github.com/clojure/core.match/wiki/Basic-usage#guards
19:58	crazydiamond	Hi. Are there data structure processing algorithms that require state by definition? I have solved my idea with a bit of imperative code, but not sure that I can turn it into pure functional
19:59	justin_smith	crazydiamond: there is a proof that any mutation can be refactored into extra args / return values that are threaded through the code
19:59	justin_smith	this is very easy to do with loop
19:59	clojurebot	Roger.
19:59	justin_smith	clojurebot: I wasn't talking to you
19:59	clojurebot	Cool story bro.
19:59	crazydiamond	justin_smith, interesting
20:00	justin_smith	crazydiamond: of course where this gets tricky is if you had multiple mutations within one loop
20:00	justin_smith	then you need to refactor things so there is one threading of the updated values from top to bottom
20:00	crazydiamond	so, my example: I have DS like this [[1] [[1]]]. I want to take out common parts [1]
20:01	crazydiamond	there's it solved in imperative way with Python: 4
20:01	crazydiamond	[(0, 1), (1, [0]), (2, [1]), (3, [2]), (4, [1, 3])]
20:01	crazydiamond	i.e. 4 is list (say, vector) with 1 and 3:
20:01	crazydiamond	[0_] [2_]]
20:02	justin_smith	I have no idea what any of this means, sorry
20:03	crazydiamond	well... imagine (clojure.walk/postwalk f some-data-structure)
20:03	crazydiamond	where (defn f [x] (do (println x) x)))
20:03	crazydiamond	i.e. prints and returns the value
20:04	bbloom	crazydiamond: if you need state over a traversal, idiomatic clojure is to simply use mutable state
20:04	crazydiamond	and I want to gather that values instead of returning them
20:04	bbloom	crazydiamond: unless you need something more advanced, like the ability to backtrack or go down multiple traversal paths in a non-standard order or something
20:04	bbloom	crazydiamond: however, if you are interested in how you'd do this more functionally just b/c, then may i suggest looking at zippers
20:05	gfredericks	~zippers \|are\| the lenses of monads
20:05	clojurebot	c'est bon!
20:06	crazydiamond	well, traversal, when I visit each node-by-node
20:06	crazydiamond	i.e. next node knows about what happened when visiting all previous
20:07	crazydiamond	in typical traversal it knows only about it's parents
20:07	crazydiamond	not siblings
20:07	justin_smith	crazydiamond: what about just using tree-seq
20:07	crazydiamond	I should check that out
20:08	justin_smith	and having a reduce over the tree-seq that carries the state you care about in the accumulator
20:08	bbloom	crazydiamond: do you care about the context of the tree? ie parents/siblings, or do you only care about the state threaded through the traversal?
20:08	bbloom	if just the state, yeah tree-seq is what you want
20:08	bbloom	if actual parents/children/etc, then look at zippers
20:08	crazydiamond	state, yes
20:08	bbloom	in both cases, it's just a "left fold"
20:08	crazydiamond	how to say that...
20:09	bbloom	the idea is to flatten the traversal of the tree in to something like a list, then reduce over the list + some state
20:09	crazydiamond	I have structure with huge amount of repeating parts
20:09	crazydiamond	I want to achieve the same goal what "let" is for
20:09	crazydiamond	say that
20:10	emaczen	is there a flat-map function in clojure?
20:10	emaczen	In CL I did reduce #'append
20:10	justin_smith	emaczen: apply concat
20:10	crazydiamond	[[1] [[1]]] become (let [a [1]] [a [a]])
20:10	emaczen	I'd rather use something like flat-map though
20:10	justin_smith	or mapcat
20:10	bbloom	,(reduce (fn [acc x] (update-in acc [x] (fnil inc 0))) {} (tree-seq vector? seq [[1] [1 [1] [1]]]))
20:10	clojurebot	{[1 [1] [1]] 1, 1 4, [1] 3, [[1] [1 [1] [1]]] 1}
20:10	bbloom	crazydiamond: something like that ^^
20:11	justin_smith	,(frequencies (tree-seq vector? seq [[1] [1 [1] [1]]])))
20:11	clojurebot	{[[1] [1 [1] [1]]] 1, [1] 3, 1 4, [1 [1] [1]] 1}
20:11	justin_smith	:)
20:11	bbloom	justin_smith: yes, but that won't teach him how to use reduce to emulate state
20:11	bbloom	:-P
20:12	justin_smith	of course
20:12	crazydiamond	uhm, that's exciting anyway
20:12	crazydiamond	thanks!
20:12	crazydiamond	Uncle Bob was talking "with state monad you may have state when you haven't"
20:12	crazydiamond	so this must be the case
20:12	justin_smith	crazydiamond: bbloom: I finally realized that weird vector of numbers and vectors above was probably just "frequencies" over subtrees
20:13	justin_smith	crazydiamond: the one where I was just like "wait, I don't even know what that is supposed to be"
20:13	emaczen	Is there a mutable version of map like forEach?
20:13	bbloom	,(reduce (fn [acc x] (update-in acc [x] (fnil inc 0))) {} (tree-seq vector? seq [[:x] [:x [:x] [:x]]])) ; clearer
20:13	clojurebot	{[:x [:x] [:x]] 1, :x 4, [:x] 3, [[:x] [:x [:x] [:x]]] 1}
20:13	justin_smith	doseq
20:13	emaczen	ehh nvm
20:13	bbloom	emaczen: in clojure 1.7 there will be run!, but yeah, doseq is what you have to use otherwise
20:14	emaczen	what is run!
20:14	bbloom	,clojure-version
20:14	clojurebot	{:interim true, :major 1, :minor 7, :incremental 0, :qualifier "master"}
20:14	bbloom	,(run! prn [1 2 3])
20:14	clojurebot	1\n2\n3\n
20:14	bbloom	,(doc run!)
20:14	clojurebot	"([proc coll]); Runs the supplied procedure (via reduce), for purposes of side effects, on successive items in the collection. Returns nil"
20:23	emaczen	how do you refer to a function without the (fn [x] ...)
20:23	emaczen	sorry let me restate
20:24	emaczen	Instead of (fn [x] (some-function(x)))
20:24	emaczen	Can you do #'some-function?
20:24	Bronsa	emaczen: assuming you mean (fn [x] (some-function x)), that's equivalent to some-function
20:25	timvisher	emaczen: what are you trying to achieve?
20:25	Bronsa	emaczen: and more or less equivalent to #'some-function too if you don't take into account var redefinition
20:25	timvisher	given your nick, are you thinking that passing a function to another one requires special quoting like it does in elisp?
20:25	emaczen	I got it -- in common-lisp often you will write (mapcar #'some-function some-list)
20:25	emaczen	In clj you can just write the function
20:25	timvisher	yeah, in clojure that's just (map func ...)
20:26	timvisher	yep
20:26	Bronsa	emaczen: #' in clojure doesn't mean what it means in cl
20:26	emaczen	I was trying all of these weird # combos
20:26	timvisher	emaczen: glad you're sorted out :)
20:26	justin_smith	but funny enough it will sometimes look like it is
20:27	justin_smith	,(map #'inc (range))
20:27	clojurebot	(1 2 3 4 5 ...)
20:31	emaczen	thanks for all the help today guys -- getting spun-up on Clojure from common-lisp is really fun!
20:32	justin_smith	Empperi: I think it'll grow on you as well
20:36	vas	datomic is really cool
20:43	crazydiamond	can "loop"s be nested?
20:44	justin_smith	yes
20:44	justin_smith	the recur will work going to the innermost loop in the context
20:45	crazydiamond	is there "depth" function with signature like tree-seq's one? :D
20:49	gfredericks	what would it return?
20:50	gfredericks	the depth of the input?
20:50	crazydiamond	yes
20:50	crazydiamond	I have written one, though (but simpler one)
20:51	crazydiamond	http://dpaste.com/1MENVQ7
20:53	gfredericks	,(defn tree-depth [branch? children root] (let [walk (fn walk [node] (if (branch? node) (inc (reduce max (map walk (children node)))) 0))] (walk root)))
20:53	clojurebot	#'sandbox/tree-depth
20:53	gfredericks	,(tree-depth 4)
20:53	clojurebot	#<ArityException clojure.lang.ArityException: Wrong number of args (1) passed to: sandbox/tree-depth>
20:53	gfredericks	,(tree-depth coll? seq 4)
20:53	clojurebot	0
20:53	gfredericks	,(tree-depth coll? seq [4])
20:53	clojurebot	1
20:53	gfredericks	,(tree-depth coll? seq [4 [1]])
20:53	clojurebot	2
20:53	gfredericks	,(tree-depth coll? seq [4 [[4] 1]])
20:53	clojurebot	3
20:54	gfredericks	somethinglikethat
20:54	gfredericks	I think it crashes on an empty collection so good luck
20:54	crazydiamond	cool, thanks
20:56	gfredericks	I don't know what an empty collection means in terms of depth anyhow
20:56	crazydiamond	either +1 or +0 :D
20:56	gfredericks	yeah one of those
21:03	arohner	when using #'proxy, is there a way to proxy the constructor?
21:10	crazydiamond	,(defn tree-depth-check-empty [branch? children empty root] (let [walk (fn walk [node] (if (branch? node) (let [children (children node)] (if (empty? children) empty (inc (reduce max (map walk children))))) 0))] (walk root)))
21:10	clojurebot	#'sandbox/tree-depth-check-empty
21:10	crazydiamond	,(tree-depth-check empty coll? seq 4)
21:10	clojurebot	#<CompilerException java.lang.RuntimeException: Unable to resolve symbol: tree-depth-check in this context, compiling:(NO_SOURCE_PATH:0:0)>
21:10	crazydiamond	,(tree-depth-check-empty coll? seq 4 0)
21:11	clojurebot	0
21:11	crazydiamond	,(tree-depth-check-empty coll? seq 4 1)
21:11	clojurebot	0
21:11	crazydiamond	,(tree-depth-check-empty coll? seq [4] 1)
21:11	clojurebot	0
21:11	crazydiamond	,(tree-depth-check-empty coll? seq 0 [4])
21:11	clojurebot	1
21:11	arrdem	o/
21:11	crazydiamond	LOL
21:11	crazydiamond	so many arguments so easy to mess up
21:50	mistaBIZ	Wow its deep
22:03	devll	hi, I deployed a clojar from the latest source,but I am getting this error
22:03	devll	Caused by: java.lang.IllegalArgumentException: Can't define method not in interfaces: with_meta, compiling:(clj_http/headers.clj:105:1)
22:04	devll	code is here. https://github.com/dakrone/clj-http/blob/master/src/clj_http/headers.clj#L120
22:05	devll	how can I resolve this?
22:06	arrdem	devll: what's the full stack trace and what else are you using/doing?
22:06	arrdem	devll: just that isn't enough to go on besides telling you to open an issue on the clj-http bugtracker.
22:06	arrdem	and even that may not be in order depending on what you're up to..
22:08	devll	this is a known issue for long
22:09	devll	clj-http 1.0.1 does not support clojure 1.7
22:09	devll	which is the latest version for clj-http
22:10	arrdem	https://raw.githubusercontent.com/dakrone/clj-http/1.0.1/project.clj
22:10	devll	http://pastebin.com/1Ld4D8Q7
22:10	devll	full trace here
22:11	arrdem	clj-http 1.0.1 doesn't depend on any version of Clojure. In fact it explicitly excludes any specific version of clojure from its transitive deps. You're probably trying to use 1.7-alphaN which doesn't work.
22:12	devll	yes.
22:14	arrdem	what are we on... alpha4 right now?
22:14	arrdem	doesn't look like there's a matching issue on jira..
22:14	devll	compability fix has been merged into clj-http master.
22:14	devll	there is but closed
22:15	devll	alpha5
22:16	arrdem	devll: what commit fixes this? I'm not seeing one but still looking.
22:17	devll	https://github.com/dakrone/clj-http/commit/ccd4f10ce9fc748a882b27d57408145cb3e3b057
22:17	arrdem	that shouldn't fix the issue you posted a stacktrace for...
22:18	devll	it fixes another issue
22:18	arrdem	right.
22:18	arrdem	but not the one you seem to care about.
22:18	enn	I'd like to find a way to figure out whether a certain function is anywhere on the call stack. I thought I'd be able to do this by examining the JVM stacktrace, but I've run into a wall.
22:19	enn	If I have a function: (def foo [] (map bar some-sequence)), and I look at the stacktrace (with (.. Thread currentThreat getStackTrace)) from within bar, foo doesn't appear anywhere, because by the time the sequence is realized foo has already completed.
22:20	devll	using clj-http 1.0.1 causes "update" related issue. using the latest build throws the error above
22:20	arrdem	devll: my gut is that you've found a bug in the alpha and should probably report it.
22:20	devll	OK
22:20	enn	So I guess what I'd like is a way to get the "logical" call stack. Does such a thing exist?
22:21	devll	I am downgrading to 1.6.0
22:21	arrdem	enn: no, Clojure keeps no "logical" call stack.
22:21	devll	for this though
22:21	devll	or my online app will not work.
22:21	enn	arrdem: well, shoot. OK, thank you.
22:21	arrdem	enn: so you're hitting an issue with lazy evaluation.
22:22	devll	thanks arrdem as well
22:22	enn	yeah
22:22	arrdem	enn: if you _really_ want to see foo in your stack, try mapv (which is strict) or use doall
22:22	arrdem	$grim clojure.core/doall
22:22	lazybot	http://grimoire.arrdem.com/1.6.0/clojure.core/doall
22:22	arrdem	$grim clojure.core/mapv
22:22	lazybot	http://grimoire.arrdem.com/1.6.0/clojure.core/mapv
22:23	enn	arrdem: unfortunately this is in the context of instrumenting arbitrary code, so I can't really banish lazy sequences altogether
22:25	enn	I guess plan B is, alter-var-root on the function I'm looking for (foo) so that it dynamically binds some flag, which I can then check for in bar
22:26	arrdem	enn: I guess that could work..
22:26	arrdem	I think dynalint and some other tools do some similar var introspection hackery to build a logical call stack.
22:26	arrdem	tracer...? it's been a long time since I used it last.
22:27	arrdem	https://github.com/xumingming/tracer
22:27	arrdem	https://github.com/clojure/tools.trace
22:28	arrdem	I'm pretty sure both of those do var poisoning akin to what you're after... as does technomancy/radagast
22:28	amalloy	enn: dynamically binding a flag will have exactly the same problem
22:29	amalloy	foo has finished by the time you realize the results of map, so of course the flag will no longer be dynamically bound either
22:29	enn	amalloy: yeah, I just discovered that. Damn.
22:31	enn	What I'm trying to do is implement something like tools.trace, with an option to only trace function bar when it is called down-stack of foo. (This is a shameless copy of the :wherein option to SBCL's trace, http://www.sbcl.org/manual/#Function-Tracing.)
22:31	enn	But it sounds like this is not possible in the general case in Clojure.
22:31	clojurebot	'Sea, mhuise.
22:31	gfredericks	oh because of laziness?
22:31	enn	Yeah
22:32	gfredericks	maybe if you modified the lazy-seq macro, but that sounds sooper hairy
22:32	gfredericks	i.e., it could save your dynamic bindings before executing the thunk
22:32	gfredericks	or something I mean youseewhatimsayin
22:33	gfredericks	I think modifying the lazyseq macro like that might be damn near impossible though w/o forking clojure
22:34	enn	yeah, I'd be worried about things breaking
22:53	arrdem	I assume that the string "RELEASE" as a lein version specifier refers the latest release?
22:54	arrdem	Just trying to grok how this works https://github.com/lshift/cloverage/blob/master/lein-cloverage/src/leiningen/cloverage.clj#L9
23:02	WonkyWombat	Hi all, I'm a Clojure-N00b and get it power in using the JVM platform but can Clojure operate on it's own in a desktop or server, not using the JVM for delivery?
23:03	gfredericks	not clojure the jvm language, no
23:04	WonkyWombat	gfredericks: right, does Clojure have access to libs or frameworks for TCP/IP-systems frameworks?
23:05	gfredericks	only inasmuch as Java does
23:05	gfredericks	for questions like that you can consider Clojure to be just a java library
23:05	WonkyWombat	gfredericks: that puts it into perspective
23:06	WonkyWombat	So it may not be the best choice for writing a tool that can almost forensically examines, reports and backups a web site/application?
23:08	WonkyWombat	gfredericks: thanks for the candour, I'll read further on Java's ability for networking
23:08	gfredericks	np
23:08	juggernot	WonkyWombat: it might be since that seems like a long running process
23:09	juggernot	is there a particular reason you want to avoid Java/JVM?
23:09	WonkyWombat	juggernot: Have this perhaps incorrect view that Java is second rate with networking compared to Python etc
23:11	juggernot	oh i see... well there's always the ClojureScript on nodejs route if you dont have any qualms about nodejs
23:12	WonkyWombat	juggernot: k, aware but have not read up
23:47	WonkyWombat	Did we have a net split or something? Awful lot of In/Out