#clojure – 2015-05-15

2015-05-15

01:45	shalom1024	does have any ideas about a most convenient way to display an incanter graph in a seesaw app?
02:38	oddcully	tieTYT: it has. try youtube-dl to fetch it (unless you meant blocked blocked)
03:11	myguidingstar	tieTYT, you can use this to download from infoq https://github.com/myguidingstar/infoq-downloader
03:42	escherize	is there a trick to using dedupe on a channel?
03:44	escherize	Basically, I am using a pipeline with a chan like (chan 1 (dedupe)) and it's not working. I'm pretty sure I'm doing something wrong
08:18	sw1nn	escherize: (unique (chan)) ?
08:35	piranha	hey all! So I have this base64 value, which I can't decode properly with data.codec: http://paste.in.ua/10729/ - any ideas what's going on here?
08:41	hyPiRion	piranha: I guess you should remove the newlines in the base64 value
08:41	piranha	oh
08:41	piranha	where they came from!
08:42	piranha	hyPiRion: yeah, that helped
08:42	hyPiRion	no idea. Weird that b64 doesn't complain about that though
08:43	piranha	carmine gave me newlines inside of a value
08:43	piranha	why'd it do that to me :(
08:44	piranha	oh, newlines are there in the first place, ok
08:44	piranha	that seems like a feature of python's base64
08:45	hyPiRion	Yeah, most base64 decoders seems to skip whitespace
08:47	piranha	hyPiRion: thanks! :-)
09:41	Chauncey	Has anyone an idea what might cause a (defrecord Foo ..) to define a my-ns/->Foo instead of a my-ns/Foo ?
09:43	luxbock	Chauncey: it should define both
09:43	luxbock	->Foo is a constructor function that gets defined for each record you define
09:44	luxbock	there's also map->Foo
09:44	Chauncey	aha, interesting, never knew that
09:44	Chauncey	But the original Foo is missing Oo
09:45	Chauncey	I had it in a different namespace before, where I could create records that the other namespace would later complain about as not implementing the protocols I made them implement
09:48	xeqi	Chauncey: are you `:import`ing Foo?
09:49	Chauncey	xeqi: no, the namespace in question only has quil and ... stacktraces required..
09:51	Chauncey	it does have [quil.core :refer :all], but I don't see how that could be a problem
09:52	Chauncey	Also, there are two records that have only these constructor methods available
09:52	Chauncey	So if it was shadowing, it'd be a pretty large coincidence
09:58	Chauncey	anyone? I am really confused, and not making any progress
10:01	TimMc	Chauncey: You need to (:import other.ns.Foo), not just (:require other.ns)
10:01	chouser_log	(defrecord Foo) doesn't define a var named Foo, but a class named your.namespace.Foo
10:01	TimMc	Very common mistake. Require'ing the ns loads the defrecord and creates the class, but to refer to the class as Foo you need to import it.
10:01	TimMc	^ ANd that, yeah -- Foo isn't a var.
10:02	Chauncey	ok, I see, thanks
10:02	Chauncey	That clears that up... So if I have a main drawing quil namespace with a drawable protocol, and I implement the protocol in another namespace, do I need to import that namespaces record into the quil ns too to make it know about it?
10:03	Chauncey	for some reason that doesn't work either
10:05	fourq	morning all
10:05	Chauncey	fourq: Morning
10:05	Chauncey	Does namespace loading order have anything to do with the quil thread knowing about implementations?
10:13	TimMc	It shouldn't!
10:13	TimMc	Unless the Quil thread uses reflection to load it, like Class/forName.
10:14	TimMc	If the ns block requires the ns that has the defrecord, you should be fine.
10:14	Chauncey	well, if it does I didn't write that :)
10:14	Chauncey	hmm
10:14	Chauncey	weird
10:15	xeqi	Chauncey: so you have a quil ns that defines the protocol. You have a second namespace that defines a record that implements the protocol. Which one is creating the instance of the record?
10:15	TimMc	You only need to require or import where you're going to reference something. (Exception: Making sure protocols and multimethod implementations get loaded.)
10:15	Chauncey	TimMc: yeah, that's what I expected too
10:15	Chauncey	xeqi: I create the instances in the other, non-quil ns that defines them
10:16	Chauncey	I tried moving them around, that's when the missing Foo occured ;)
10:18	Chauncey	well, I moved everyhing into the ns defining the protocol and imported it into the other, that seems to have done the trick
10:18	Chauncey	Still confused though
10:19	Chauncey	Thanks for your help guys! Moving on...
10:19	xeqi	Chauncey: were you reloading the file with the `defprotocol`? That would redefine it and make it so any instances of it before redefinition were invalid
10:20	Chauncey	xeqi: I noticed that too, but I changed the code to recreate the instances after reloading
10:21	Chauncey	there is basically one test function that does all the setup (conj drawables into an atom which is in the quil state)
10:29	luxbock	are there any other attributes besides :pre and :post that are used?
10:37	timvisher	am i supposed to use extend or extend-protocol to extend a protocol to a new type?
10:42	puredanger	extend should be considered low-level and not used directly
10:42	puredanger	use extend-protocol to extend a protocol to one or more new types
10:42	puredanger	use extend-type to have a type extend one or more protocols
10:43	puredanger	if you have 1 type and 1 protocol then flip a coin :)
10:45	gfredericks	(defmacro extension-roulette [one-thing another-thing & methods] (if (zero? (rand-int 2)) `(extend-protocol ~one-thing ~another-thing ~@methods) `(extend-type ~one-thing ~another-thing ~@methods)))
10:47	Chauncey	gfredericks: that is a little buggy, but I like it :D
10:48	TimMc	gfredericks: Would you accept a PR moving the if expression into the head of the extension call?
10:48	Chauncey	also on of your things is a protocol and the other is a type, so one-thing can't always be first
10:49	Chauncey	but apart from that, it's core-worthy :D
10:50	gfredericks	@TimMc I think everything that can reasonably vary should vary
10:52	Chauncey	haha, you evil, evil man
10:53	gfredericks	good morning everybody
10:54	xeqi	does cider have a load this file into the repl, and any files that :require it command?
10:56	TimMc	xeqi: As in, reload this file and all dependants?
10:56	xeqi	yes
10:57	xeqi	cfleming: ^ that is what cursive's" Load file in REPL" does right?
10:58	xeqi	or am I reading https://cursiveclojure.com/userguide/repl.html backwards
11:01	crocket	clojure for the brave doesn't explain destructuring comprehensively.
11:01	crocket	Does anyone knk
11:02	crocket	Does anyone know a better learning material?
11:03	gfredericks	irc is pretty good
11:03	gfredericks	because destructuring isn't too complicated
11:04	gfredericks	so if you just ask questions about whatever info you're missing it'll probably be comprehensive pretty quick :)
11:04	TimMc	crocket: I don't know why it's on this page, but here's something: http://clojure.org/special_forms#binding-forms
11:06	TimMc	puredanger: ^ I'm guessing destructuring used to be part of the compiler and was later moved to the destructuring macro?
11:06	puredanger	dunno, predates me :)
11:08	crocket	gfredericks : I will not know what I miss.
11:09	puredanger	http://blog.jayfields.com/2010/07/clojure-destructuring.html is pretty good
11:10	crocket	Du....
11:15	TimMc	puredanger: Oh, I'm in the comments there, being an adorable Scheme immigrant!
11:16	puredanger	welcome to our land of many types of brackets
11:16	mdrogalis	puredanger: Predates almost everyone https://twitter.com/chrishouser/status/599221332715307008
11:16	crocket	braveclojure.com doesn't explain :or keyword in destructuring.
11:16	alexbaranosky999	dumb question guys: I thought in cider on Emacs I could M-. into a jar and compile changes in it. Is that true?
11:17	TimMc	puredanger: I remember finally realizing that let and let* did not mean the same thing as in Scheme. (I think let* allows multiple bindings? I've forgotten by now.)
11:18	puredanger	alexbaranosky999: I think you can M-. into a jar and change .clj files (which I think is pretty evil actually)
11:20	arohner	alexbaranosky999: puredanger: both are true
11:20	TimMc	Can confirm, have done this on a running server and reloaded the code.
11:20	arohner	you can edit files in the jar, and you can also C-c C-k the modified source file, w/o saving
11:20	TimMc	Have not needed to do this on a production server, thank goodness.
11:29	TimMc	("What do you think this is, an Erlang shop?")
11:35	alexbaranosky999	puredanger: arohner: I thought so, thanks. I need to basically debug a jar we're using, and wasn't seeing my changes reflect when compiling
11:35	alexbaranosky999	In general I agree, it's a little evil
11:35	arohner	not something you should make a habit of, but it can be a lifesaver
11:36	puredanger	it's ok if you actually notice you're doing it. I've done it accidentally before though and really caused myself some head-scratching later.
11:36	alexbaranosky999	arohner: as you an see I haven't done it in so long, I forget if it is possible! :)
11:38	TimMc	puredanger: Oh yikes, hadn't thought about the implications of M-. specifically. I don't have that integration running most of the time, so I just open the jar file directly and find the appropriate .clj.
11:38	TimMc	I can totally see doing it by accident.
11:38	puredanger	I've had that happen where we had a multi-module project so I was still in "our" code, just different "project"
11:40	alexbaranosky999	puredanger: yeah if you don't notice, that can be a big-time pain later to figure out
12:09	crocket	Does anyone know a better book than braveclojure.com ?
12:10	pbx	crocket, i'm enjoying the o'reilly book
12:10	pbx	aka http://shop.oreilly.com/product/0636920013754.do
12:10	wasamasa	crocket: living clojure is cool
12:11	TimMc	crocket: Better in what sense? Is the style just not matching? Too fast? Too slow?
12:11	TimMc	~books
12:11	clojurebot	books is http://www.pragprog.com/titles/shcloj/programming-clojure
12:11	TimMc	among others
12:13	crocket	TimMc, braveclojure didn't mention :or keyword when describing destructuring maps.
12:14	mp	.wc
12:26	crocket	I think braveclojure is ok in overall, but I'm afraid that it might be missing important details.
12:26	tmarble	macro help needed! I want to create a defrecord with type hints http://paste.debian.net/plain/177667 (but as real ^String not "^String")??
12:26	lazybot	tmarble: What are you, crazy? Of course not!
12:26	puredanger	no one resource covers 100% of the details
12:27	sdegutis	When is Clojure 1.7.0 expected?
12:27	puredanger	braveclojure is a great fun introduction that covers lots of useful stuff. I would augment with at least one more to get more complete coverage.
12:28	puredanger	sdegutis: at this point, I think there is maybe 1 or 2 items that need attention. assuming no other reports from beta 3, I'm hoping we can do rc1 next week and then it's just a matter of getting enough feedback that we feel ok cutting a release
12:28	crocket	puredanger, one more book?
12:28	sdegutis	Nice.
12:28	crocket	duh
12:28	sdegutis	puredanger: thanks
12:28	crocket	Do people use :or keyword in destructuring maps?
12:28	puredanger	crocket: yes, for defaults
12:29	crocket	puredanger, defaults?
12:29	puredanger	we actually cover that use case in "Clojure Applied"
12:29	crocket	puredanger, We?
12:29	puredanger	like: I get a map of options, but want to supply defaults if some options aren't supplied
12:29	puredanger	"we" = me and Ben Vandgrift, as authors
12:30	puredanger	In https://pragprog.com/book/vmclojeco/clojure-applied
12:31	crocket	Which book do I better read after 'braveclojure?
12:31	chouser	tmarble: maybe ~@(map #(vary-meta % assoc :tag 'String) args)
12:31	puredanger	that book is designed as an intermediate book btw, and is use-focused (I need to do X) rather than feature-focused. it intentionally leaves out lots of features.
12:32	puredanger	crocket: if you want other intro books, I think the O'Reilly and Pragmatic ones are also pretty thorough. Programming Clojure and Clojure Programming, whichever matches those correctly. :)
12:33	puredanger	it's pretty old now, but I like the treatment of certain subjects a lot in Practical Clojure by Apress too.
12:34	crocket	I don't see a difference between clojure's built-in repl and lein repl.
12:34	crocket	lein repl seems to use nREPL which just looks like clojure's built-in repl.
12:36	zerokarmaleft	crocket: it also incorporates REPL-y, which provides some niceties summarized at the top of the README https://github.com/trptcolin/reply
12:41	crocket	zerokarmaleft, How do I get lein repl outside leiningen?
12:42	verma	hey, in cursive, is there a quick way to reformat a form, like the Meta-q stuff in emacs?
12:43	verma	I see some talks/screencasts that seem to do it, but I am not sure how that is done
12:45	fourq	How is the addition symbol considered a truthy value? Just because it's not a false/nil value?
12:45	fourq	;; Return value of "or" is first truthy value, and + is truthy
12:45	fourq	(or + -)
12:45	tmarble	chouser: thx, but I get (clojure.core/defrecord fred [a b]) ;; this is a real brain teaser!
12:45	fourq	since (or - +) returns -
12:48	zerokarmaleft	crocket: I'm not sure I understand your question...you can run `lein repl` independent of any particular project
12:53	gfredericks	tmarble: you do need vary-meta
12:54	gfredericks	tmarble: try (set! print-meta true) at the repl, then inspect the output again
12:54	gfredericks	tmarble: the ^String syntax sets metadata on the symbol, and metadata normally isn't printed
12:54	tmarble	gfredericks: ok, i'll try that
12:55	tmarble	gfredericks: you and chouser are correct! thank you!
12:55	gfredericks	(inc me-and-chouser)
12:55	lazybot	⇒ 1
12:56	TimMc	$karma zerokarmaleft
12:56	lazybot	zerokarmaleft has karma 1.
12:56	TimMc	hmmm
12:58	justin_smith	(identity justin_smith hyPiRion)
12:58	lazybot	justin_smith hyPiRion has karma 1.
12:59	justin_smith	(identity hyPiRion justin_smith)
12:59	lazybot	hyPiRion justin_smith has karma 1.
12:59	justin_smith	symmetry
13:00	crocket	http://shop.oreilly.com/product/0636920013754.do contains 630 pages, and https://pragprog.com/book/shcloj2/programming-clojure contains a lot less pages.
13:00	crocket	Does it mean the former has a lot more details?
13:00	crocket	Or, is it just verbose?
13:01	TimMc	(identity gfredericks and chouser)
13:01	lazybot	gfredericks and chouser has karma 0.
13:02	gfredericks	(identity me-and-chouser)
13:02	lazybot	me-and-chouser has karma 1.
13:02	gfredericks	woooh
13:09	m1dnight1	guys, im having some issues importing a java class in clojure. I have done it before and I think i have reproduced everything I had to, but its giving me "no such namespace"
13:10	m1dnight1	What I have done so far is: add :java-source-paths ["interop"] to my project.clj, give the class the packagename "actors", and then in my code I do: (:import [actors BlockingStore]))
13:10	m1dnight1	when I do lein run, it compiles the java class. so thats good, I guess.
13:12	m1dnight1	the parts in my source are literally copy pasted from my other project, so i dont see whats wrong. the only difference now is that the class that is trying to import it is not in my "root" namespace, it is in projectname.foo.bar
13:12	crocket	Should I read http://shop.oreilly.com/product/0636920013754.do or https://pragprog.com/book/shcloj2/programming-clojure ?
13:14	zerokarmaleft	crocket: I've read both...you won't regret reading either of them
13:16	crocket	zerokarmaleft, It seems I better read the larger book...
13:16	crocket	One book to rule clojure.
13:17	crocket	As I guessed, the larger book goes very deep.
13:48	andyf	gfredericks: I see you did some changes to dynalint a while back, and I think you noted that lein-dynalint seems to be giving warnings for the Leiningen JVM. Do you know if it gives warnings for both Leiningen JVM and project JVM, or only Leiningen JVM?
13:53	irctc	Is there a core function to test if a String contains a number? (numeric? "-0.3") ; true (found one here as a backup: http://rosettacode.org/wiki/Determine_if_a_string_is_numeric#Clojure)
14:01	andyf	irctc: Only Java interop available, or a sufficiently complex regular expression and re-match
14:02	andyf	irctc: Java's parseDouble may be what you want: https://docs.oracle.com/javase/7/docs/api/java/lang/Double.html#parseDouble(java.lang.String)
14:03	irctc	andyf: thanks. I'll use the rosettacode for now, which of course uses interop.. True, I could try to proactively parseDouble and catch the exc, but generating a stack trace is too costly.
14:04	andyf	irctc: There is no need to generate a stack trace if you catch the exception, yes?
14:05	irctc	andyf: the act of throwing an Java exception creates a stack trace in the exception object. Not talking about printing it.
14:06	irctc	andyf: in other words when a Java exception is thrown the stack is captured and stored in the exception in case you need it.
14:06	andyf	irctc: I was not aware of that. Out of curiosity, have you measured performance impact of that?
14:07	irctc	andyf: this is how you can ask the exception object later to print the trace.
14:09	irctc	andyf: not with this particular issue. There's a lot on the topic. For instance. http://stackoverflow.com/questions/299068/how-slow-are-java-exceptions
14:09	irctc	andyf: bottom line, if performance matters don't throw exceptions.
14:09	tcrayford____	Not always though
14:10	tcrayford____	Some exceptions don't have stacktrace said after getting JITd
14:10	tcrayford____	Which makes for fun debugging :/
14:10	irctc	tcrayford: Yes, I suppose there are always exceptions to the rule. :/
14:11	tcrayford____	See http://yellerapp.com/posts/2015-05-11-clojure-no-stacktrace.html
14:11	tcrayford____	There's links to good references on the perf side in there
14:12	irctc	tcrawford: Thanks for the link. They mention, "perf implications" for turning stack trace generation.
14:13	tcrayford____	(I wrote that post)
14:13	irctc	tcrawford: ... on
14:13	gfredericks	andyf: I don't recall, but if I had to guess it would be lein-vm-only
14:13	gfredericks	seems more complicated to somehow end up doing both
14:13	tcrayford____	There are references in it to real perf posts on the topic
14:14	irctc	tcrawford: sweet!
14:14	tcrayford____	See http://shipilev.net/blog/2014/exceptional-performance/
14:14	andyf	gfredericks: So lein-dynalint isn't terribly useful as is now, then?
14:14	tcrayford____	And http://normanmaurer.me/blog/2013/11/09/The-hidden-performance-costs-of-instantiating-Throwables/
14:15	gfredericks	andyf: that sounds right
14:16	andyf	gfredericks: Have you learned of any simple way to use dynalint to check for errors in your own project's code?
14:16	irctc	andyf: this is the performance hit when throwing, Throwable.fillInStackTrace(). It walks up the stack.
14:16	andyf	irctc: Makes sense.
14:16	gfredericks	andyf: my wording in the issues "just lint the leiningen process" backs up my previous guesses
14:17	gfredericks	andyf: I haven't been using it personally, but your question is confusing -- isn't that the entire point of using it?
14:18	andyf	gfredericks: Definitely it is the entire point. If lein-dynalint doesn't do it, is the only out-of-the-box way to use dynalint on your own project's code to invoke the documented commands in a REPL session?
14:19	gfredericks	andyf: being totally ignorant I imagine some sort of lein alias could accomplish it as well
14:19	gfredericks	or `lein run` command rather
14:19	gfredericks	(which could be aliased)
14:20	andyf	gfredericks: I'm being a bit lazy by asking you, sorry. I can figure it out given enough time. Just checking what you recalled off the top of your head.
14:23	gfredericks	no problem
14:28	borkdude	do you guys ever feel the urge to refactor something you think can be better, outside work hours without getting paid for it by the customer?
14:28	brucehauman	borkdude: yep
14:29	gfredericks	I try to resist though
14:29	borkdude	I thought about it all day while I'm having a vacation...
14:29	brucehauman	borkdude: I feel like its a natural response, but yeah, you should probably not do it, unless it will make your life that much better
14:30	brucehauman	borkdude: you can sometimes get paid fo rthis down the line
14:31	brucehauman	borkdude: but you are much better off selling it and getting paid for it
14:31	gfredericks	I at least put refactoring ideas in comments so they don't get completely lost when I forget about them
14:31	wink	borkdude: I can easily reist this. but what I have done was "we need to do x" - "we can only do this if there's an opensource lib for it" .. next day "here look, I found this open source lib [in my github account...]"
14:32	brucehauman	lol
14:32	borkdude	wink :)
14:32	borkdude	in my case it's more about a database schema. it now uses "table per concrete type" while things would be more simple with "table per type"... 2 days work probably
14:33	wink	it was a simple ragel parser for js. I couldn't just let them eval() userr input
14:33	wink	I did for the greater good :\|
14:33	borkdude	as long as it's fun to do (researching a new library or technology) I don't mind it
14:33	gfredericks	I once had to deal with a legacy project that used a many-to-many join table to model a one-to-many relationship
14:34	gfredericks	but it was too legacy/complicated to refactor it
14:34	gfredericks	all that could be done was regular weeping
14:34	Seylerius	Do most win7 machines already have a JVM that can tolerate clojure?
14:35	Seylerius	And we can use java GUI kits from clojure, right?
14:35	andyf	Seylerius: You mean for Clojure development, or deploying some kind of application?
14:35	Seylerius	andyf: deployment.
14:36	Seylerius	I'm dev'ing on my linux box. Just want to know that if I drop properly compiled bytecode on 'em, it'll work.
14:36	brucehauman	borkdude: yeah database refactors … that desn’t sound like it could get out of control.
14:36	borkdude	brucehauman joking or serious?
14:37	brucehauman	borkdude: joking, sarcasm
14:37	brucehauman	borkdude: depends on the project size right?
14:38	brucehauman	borkdude: or rather the surface area that interacts with the data layer
14:39	borkdude	brucehauman right, I'll probably better make an inventory of changes before naively starting this
14:40	kaiyin	does the counts of s1 and s2 really matter here? https://github.com/clojure/clojure/blob/master/src/clj/clojure/set.clj#L37-L43
14:41	kaiyin	it's basically a nested loop over s1 and s2 anyways.
14:42	andyf	kaiyin: One way of doing it is linear time in size of s1, the other way linear time in the size of s1 (times the log of the other for each contains? call, but I'm leaving that out)
14:42	andyf	oops, 'other ... s2' is what I meant.
14:44	kaiyin	andyf: you mean contains? is way faster than reduce in this case.
14:44	andyf	kaiyin: reduce is doing a linear iteration over elements of s1 there.
14:45	kaiyin	ok, i see.
14:45	andyf	kaiyin: contains? is log time
14:45	kaiyin	contains? is probably traversing over some kind of tree structure.
14:46	kaiyin	that could "return early".
14:46	andyf	Or as some Clojure folks like to call it, "effectively O(1)" :)
14:46	kaiyin	cool.
14:48	borkdude	brucehauman thanks for the talk at clojure/west btw, I recently watched it
14:48	devn	+1
14:49	devn	(inc brucehauman)
14:49	lazybot	⇒ 1
14:49	andyf	Fine print: contains? can be linear time, but only if you use a hash set and work reasonably hard to pick many set elements that collide to same hash value
14:49	brucehauman	borkdude devn thanks, you guys are too kind, it was a lot more fun than I expected it to be
14:55	devn	brucehauman: all about your delivery man
14:55	devn	well done :)
14:55	devn	also, from where i was sitting i thought maybe you were wearing a smoking jacket, which made it even cooler
15:03	kaiyin	a function working on maps is sitting in set.clj: https://github.com/clojure/clojure/blob/master/src/clj/clojure/set.clj#L77-L86
15:04	hkjels	I'm getting a really vague error-message without line-num etc. Even with DEBUG env. Is there a way to get an even more verbose error-output?
15:05	hkjels	The error is : Error: clojure.lang.PersistentVector cannot be cast to clojure.lang.Named
15:06	devn	hrm
15:06	devn	i need a project to tinker with
15:07	amalloy	hkjels: are you in the stock clojure repl? you can get a real stacktrace with (.printStackTrace e out*)
15:08	amalloy	anyway, the error means you have a vector where a keyword/symbol/string is expected, of course. i'd guesss this is in your ns form
15:09	epichero	any suggestions for working with websockets?
15:10	hkjels	amalloy: That's the one place I haven't looked :) One sec
15:23	hkjels	amalloy: Nope, LGTM. I'm running `lein garden` when the error appears. I've now tried my styles-file with the stock repl without errors, so the problem lies elsewhere
15:29	andyf	kaiyin: Yes, that function has been in clojure.set namespace for a long time. I doubt it will move.
15:30	andyf	kaiyin: There are several functions for working on sets of maps with identical keys to each other, i.e. relations, in clojure.set namespace.
15:30	kaiyin	andyf: yeah, I am reading them.
15:46	cfleming	verma: You can select the form and then reformat, and it will format the selection. I'm planning to add a "reformat top form" action
15:47	kaiyin	is there something similar to peek for a set?
15:47	cfleming	xeqi: Right. AFAIK to get that in Emacs you need to use tools.namespace
15:49	andyf	kaiyin: No. peek is only implemented for data structures with a notion of order. Sets and maps are unordered.
15:50	andyf	Oh, well, I guess there are sorted sets and maps, too, but they also do not implement peek.
15:50	andyf	So, peek for list, vectors, queues, I think lazy sequences, too.
15:50	kaiyin	I think peek can be useful in both scenarios.
15:51	andyf	What would you want peek on a set to do?
15:51	kaiyin	well, to have a peek at it.
15:51	kaiyin	:)
15:51	andyf	You mean, return an arbitrary element of the set?
15:51	andyf	(first (seq my-set)) may do what you want
15:52	kaiyin	ah, i see.
15:52	angusiguess	,(first #{3 4 2 6 5 1})
15:52	clojurebot	1
15:52	kaiyin	,(next #{3 4 2 6 5 1})
15:52	clojurebot	(4 6 3 2 5)
15:52	andyf	oh, and of course, first calls seq on its argument, so is unnecessary in my example.
15:53	kaiyin	coll
15:53	kaiyin	cool
16:06	hkjels	amalloy: Found the issue. It was in my project-file
16:20	kaiyin	array-maps are automatically converted to hash-maps when it's over a certain size, right? what is that size limit if so?
16:26	justin_smith	,(count (first (drop-while #(= (type %) clojure.lang.PersistentArrayMap) (iterate (fn [m] (assoc m (gensym) true)) {}))))
16:26	clojurebot	10
16:26	justin_smith	kaiyin: 10
16:26	kaiyin	cool.
16:29	kaiyin	justin_smith: so {} is an array-map by default.
16:29	justin_smith	yes
16:29	justin_smith	,(type {})
16:29	clojurebot	clojure.lang.PersistentArrayMap
16:34	kaiyin	,(inc justin_smith )
16:34	clojurebot	#error {\n :cause "Unable to resolve symbol: justin_smith in this context"\n :via\n [{:type clojure.lang.Compiler$CompilerException\n :message "java.lang.RuntimeException: Unable to resolve symbol: justin_smith in this context, compiling:(NO_SOURCE_PATH:0:0)"\n :at [clojure.lang.Compiler analyze "Compiler.java" 6543]}\n {:type java.lang.RuntimeException\n :message "Unable to resolve symbol:...
16:34	kaiyin	(inc justin_smith )
16:34	lazybot	⇒ 10
16:35	kaiyin	How do you overide this behavior then, if you want to use array map with size greater than 10.
16:38	TimMc	In 1.7 they won't be array maps, I think.
16:38	TimMc	kaiyin: Why would you want to? Anyway, you can use sorted maps from some library.
16:39	kaiyin	TimMc: sorted maps aren't the same thing. I want preserve order of insertion, not by some cmp func.
16:40	TimMc	Mmmm, I see.
16:40	justin_smith	kaiyin: the number of incs of "justin_smith " is equal to the number of elements in the first hash-map that is auto-promoted from array-map
16:40	justin_smith	that's a nice coincidence
16:41	kaiyin	Indeed, :D
16:41	justin_smith	TimMc: clojurebot is running 1.7
16:42	justin_smith	kaiyin: there is an insertion-ordered map out there - maybe amalloy made it? I am forgetting right now.
16:42	whodidthis	i heard ordered map is all about that insertion order
16:42	amalloy	$google amalloy ordered
16:42	lazybot	[amalloy/ordered · GitHub] https://github.com/amalloy/ordered
16:42	amalloy	i guess i did make it!
16:43	justin_smith	(inc amalloy)
16:43	lazybot	⇒ 268
16:43	kaiyin	(inc amalloy)
16:43	lazybot	⇒ 269
16:43	kaiyin	amazing.
16:43	justin_smith	I'm catching up
16:43	justin_smith	(identity justin_smith)
16:43	lazybot	justin_smith has karma 253.
16:44	kaiyin	it's also entirely in clojure.
16:45	kaiyin	amalloy: it's not uploaded to clojars, though?
16:45	amalloy	of course it is
16:45	amalloy	(defproject org.flatland/ordered "1.5.2" ...)
16:47	kaiyin	amalloy: https://clojars.org/ordered here it says 1.3
16:47	amalloy	kaiyin: org.flatland/ordered. it has a groupid
16:49	kaiyin	yeah, what does that have to do with the version of this package? maybe a stupid question, I don't know much about maven.
16:49	justin_smith	kaiyin: every artifact has a group and a project
16:50	justin_smith	kaiyin: but lein has a convenience where if you don't have a / it makes group and project the same
16:50	justin_smith	so asking for ordered is the same as asking for ordered/ordered
16:50	justin_smith	as opposed to org.flatland/ordered
16:50	kaiyin	ok.
16:51	kaiyin	i see, there is another one. https://clojars.org/org.flatland/ordered
16:52	kaiyin	this means it's been pushed twice.
16:53	whodidthis	artifacts also sound pretty cool, they are mystical and once posted on clojars under a version you cant alter them
16:54	kaiyin	amalloy: it might be nicer if you added one or two lines about how to add this dependency in a lein project, as many clojure library github pages do.
16:54	kaiyin	just a suggestion.
16:55	cddr	So I'm writing a with-test-logger macro that catches logs so that test code can verify they have been emitted....
16:55	cddr	I've seen people suggest this might be implemented by emitting logs to a channel
16:55	cddr	What does that buy you over just appending them to a vector?
16:57	sdegutis	,[do (prn 1) (prn 2)] ;; why?
16:57	clojurebot	#error {\n :cause "Unable to resolve symbol: do in this context"\n :via\n [{:type clojure.lang.Compiler$CompilerException\n :message "java.lang.RuntimeException: Unable to resolve symbol: do in this context, compiling:(NO_SOURCE_PATH:0:0)"\n :at [clojure.lang.Compiler analyze "Compiler.java" 6543]}\n {:type java.lang.RuntimeException\n :message "Unable to resolve symbol: do in this context"...
17:00	sdegutis	CLJ-1184 should have made that work
17:01	sdegutis	Oh wait, that's fixed. Good.
17:02	TimMc	Unfortunately. It made for some fun prank code.
17:04	justin_smith	is there any plan for cljc to support tags other than clojure implementation (:clj :cljs) ?
17:04	justin_smith	plus :default, of course
17:05	justin_smith	I see :arch/osx briefly on this page, but no explanation about how this is set up stands out http://dev.clojure.org/display/design/Reader+Conditionals
17:06	puredanger	not in 1.7
17:06	justin_smith	ahh, OK
17:07	justin_smith	so it's not just reading comprehension fail on my part
17:07	puredanger	custom features were there and we pulled them out
17:07	puredanger	just narrowing scope
17:07	puredanger	may reconsider in the future
17:07	justin_smith	cool, now the puzzle pieces fit :)
17:16	wei	Is there a data structure that’s like a 1-1 map, with two-way lookup? Alternative is to use two maps, a->b and b->a
17:16	the-kenny	wei: I'd just go with the two-map approach.
17:16	TimMc	wei: Either amalloy or ztellman has probably written a library for that. :-P
17:17	kaiyin	how do you change shift width in cursive?
17:17	amalloy	well, it's not my style. who knows, maybe zach did
17:18	justin_smith	wei: I think that's known as a bi-map
17:18	the-kenny	commons has one iirc. Non-persistent, of course
17:19	justin_smith	https://gist.github.com/semperos/3835417 here is one from cgrand
17:21	TimMc	amalloy: You're the two people who write most of the collection libs.
17:21	wei	thanks for the tips! now that I have a name for this, I also found org.apache.commons.collections.bidimap.TreeBidiMap
17:22	TimMc	(Weighted by number of references I see in IRC.)
17:22	wei	gonna test out cgrand’s implementation first though, since it supports assoc and dissoc
17:23	TimMc	wei: Yeah, TreeBidiMap is mutable, which might be a problem for you.
17:25	andyf	kaiyin: You may have already gotten your question answered, but Clojure cheat sheet has several variants of ordered maps and sets linked from there: http://clojure.org/cheatsheet but versions at "Download other versions with tooltips" link near top of that page are more up to date and have tooltips
17:28	kaiyin	andyf: you mean this one? http://jafingerhut.github.io/cheatsheet/grimoire/cheatsheet-tiptip-cdocs-summary.html
17:28	kaiyin	looks quite nice.
17:31	andyf	kaiyin: There are several variations depending on whether you want links to ClojureDocs or Grimoire, but yeah
17:31	kaiyin	cool
17:54	TimMc	Anyone know of a leiningen plugin to compare dependency versions across two git commit IDs?
17:54	TimMc	I'll write it myself if no one has done this, but I don't want to do the work if it exists...
17:56	TimMc	(When I change a dependency version, I want to see what other dependencies that has changed so I can check for potential breaking changes.)
18:23	aperiodic	hey so... I feel sorta crazy for asking, but has anyone run into a problem where leiningen's `deploy` task creates jars that... don't have any code?
18:23	aperiodic	when I create a jar with `lein jar` it has my code in it
18:23	aperiodic	but when I deploy to clojars with `lein deploy clojars`, then open up the jar that gets pushed, it contains no code
18:23	aperiodic	this is with leiningen 2.5.1
18:24	TimMc	aperiodic: Do you have a public project I could look at?
18:24	aperiodic	and this project.clj: https://github.com/puppetlabs/clj-ldap/blob/master/project.clj
18:26	TimMc	aperiodic: My first recommendation is to try to reproduce it with a local filesystem repo -- add :local-test "file:///home/aperiodic/tmp" to your :deploy-repositories and do lein deploy local-test
18:26	TimMc	then move your lein profiles out of the way and see if it still happens.
18:28	aperiodic	TimMc: alright, I'll give that a shot.
18:29	TimMc	aperiodic: For what it's worth, when I deploy to a local repo, I see clj_ldap/client.clj in the jar.
18:32	aperiodic	well it doesn't happen an another project
18:37	aperiodic	yeah, I see it there too
18:39	TimMc	aperiodic: Bet it's a lein user profile.
18:42	aperiodic	TimMc: why would it only manifest in the one project?
18:43	TimMc	Hmm... another idea. Move ./target elsewhere (for forensics) and try again.
18:43	aperiodic	TimMc: yeah I still get no code in the jar that gets deployed to clojars
18:43	TimMc	Or lein clean if you just want to try and fix it and not figure out why it's busted. :-P
18:43	aperiodic	oh... I did turn off AOT in this project recently
18:44	aperiodic	thanks for your help
18:45	aperiodic	yup!
18:45	aperiodic	moving target out of the way fixed it
18:47	aperiodic	though there is no difference in terms of files present between the old target and the target after deploying a jar that actually had code
19:01	wei	protocol question. in cgrand’s bimap implementation (https://gist.github.com/semperos/3835417) i see that “without’ is defined as a protocol function. so why can I not call (without (bimap :a 1) 1) ?
19:07	amalloy	.without is a method in some interface from clojure.lang. it's not a protocol function
19:07	TimMc	aperiodic: /me waves hands and mumbles about timestamps
19:17	Seylerius	Grr... CIDER complains thusly on load: http://ix.io/izO
19:21	xeqi	Seylerius: add something like https://gist.github.com/xeqi/05d3e955aed4810302ca to your ~/.lein/profiles.clj
19:29	Seylerius	xeqi: That did the trick (with an additional "}"), thanks.
19:37	Seylerius	Can mikera's core.matrix handle 3D matrices?
20:24	Seylerius	Okay... clojure and 3d matrices. Anyone got some advice? Can mikera's core.matrix do it? Maybe a vector or matrices?
20:36	dmkolobov	Hi y'all. On the http://clojure.org/lazy page, the last paragraph describes a way of triggering `lazy-seq` compiler optimizations with a `filter` example. I've heard this referred to as "local clearing" before. From the example, does the function `f` have to declare `p` as one of its parameters? Will the compiler not optimize if `f` take the single argument `c`?
20:37	dmkolobov	my bad, the function `f` is called `step` in the example
20:53	crocket	How is lein repl different from cider repl?
20:53	crocket	Are they the same?
21:15	gfredericks	crocket: cider starts its repl via leiningen I believe
21:28	crocket	It seems cider repl is lein repl.
21:28	crocket	How clever.
21:28	gfredericks	:)
21:29	TimMc	(def cider lein)
21:29	crocket	(sum 1 help)
21:29	TimMc	Fun fact: There is actually only one program in the world; it behaves differently when called by different names.
21:38	crocket	hmm......
21:40	crocket	Hell
22:15	tolstoy	(Emacs/Cider): Is it possible to re-evaluate a defmulti and have it take?
22:29	gfredericks	defmulti is inherently re-eval-hostile
22:29	gfredericks	one workaround is to eval (def my-multi nil)
22:29	gfredericks	then eval the defmulti again
22:34	tolstoy	Ah, thanks gfredericks.
22:34	gfredericks	np
22:50	tolstoy	Worked! ;)
23:00	tmtwd	hm -
23:01	tmtwd	clojure is interopperable with java, why do wrappers exist for java libs to interact with clojure?
23:01	tmtwd	ie https://github.com/pelle/bitcljoin
23:03	gfredericks	it can make things more fluent
23:03	tmtwd	i see
23:03	TEttinger	just to make it easier, really. you can do a lot with certain clojure features that often is tricky from java, like how Seesaw is a wrapper around Swing that takes anonymous fns instead of java-style anonymous inner classes (that might be possible anyway)
23:03	TEttinger	seesaw adds a lot of functionality, like being able to get a GUI element by an ID or selector
23:04	TEttinger	many wrappers try to do the same
23:04	tmtwd	Cool
23:04	devn	TimMc: how do you mean?
23:04	tmtwd	I may take a look at seesaw, since I have some experience with swing
23:05	TEttinger	some things are kinda a pain to use from clojure if they use java conventions. arrays aren't quite as easy as they could be, and varargs in java are really just an array of arguments
23:05	tmtwd	swing is so awful, I can't believe that is how I learned to program
23:05	devn	TEttinger: IIRC someone wrote a lib to make arrays a little easier to work with
23:05	devn	tmtwd: haha
23:05	TEttinger	hiphip, yep
23:05	tmtwd	devn, java arrays?
23:05	devn	seesaw isn't so bad
23:06	devn	tmtwd: yeah
23:06	devn	TEttinger: yeah, that's the one
23:06	tmtwd	devn, why not just use vectors?
23:06	TEttinger	(arrays aren't preferred in idiomatic clojure because they aren't immutable and aren't persistent, etc.)
23:06	devn	tmtwd: performance
23:06	devn	or interop related reasons
23:06	TEttinger	but yeah they do perform very well
23:06	devn	which kind of dovetail
23:06	tmtwd	interesting
23:06	devn	i mean, there is a tradeoff
23:07	TEttinger	it's harder to get highly-mutable code that uses arrays a lot to work on the first try
23:07	tmtwd	I would have thought vectors were just arrays with a different name
23:07	devn	it's why they're a little more cumbersome to use in clojure, and frankly, i appreciate that design choice
23:07	tmtwd	but I guess vectors in clojure have to conform to lisp patters or something
23:07	devn	for java programmers, they'll want to start using arrays right away, better to lead them down the path of sanity
23:07	devn	and let them choose arrays only where they're truly necessary
23:07	gfredericks	tmtwd: they're immutable; it's a huge difference
23:07	tmtwd	gfredericks, ah of course
23:07	devn	tmtwd: are you familiar with structural sharing and all of this business?
23:08	tmtwd	but vectors are random access, no?
23:08	gfredericks	yep
23:08	devn	yeah
23:08	tmtwd	@devn no,
23:08	tmtwd	never heard of it
23:08	devn	vectors are very much like ArrayLists, except they're totally different
23:09	tmtwd	And the fact that vectors can't change size
23:09	devn	tmtwd: so, if you do this: (conj [1 2 3] 1)
23:09	tmtwd	(I think)
23:09	devn	do you make a copy of [1 2 3]? [1 2 3 1]?
23:10	tmtwd	not sure
23:10	tmtwd	is there a copy function
23:10	tmtwd	?
23:10	tmtwd	ah
23:10	devn	tmtwd: http://en.wikipedia.org/wiki/Persistent_data_structure
23:10	devn	"While persistence can be achieved by simple copying, this is inefficient in CPU and RAM usage, because most operations make only small changes to a data structure. A better method is to exploit the similarity between the new and old versions to share structure between them, such as using the same subtree in a number of tree structures."
23:10	devn	"However, because it rapidly becomes infeasible to determine how many previous versions share which parts of the structure, and because it is often desirable to discard old versions, this necessitates an environment with garbage collection."
23:11	devn	this works out on the JVM because the GC is marvelously good
23:11	devn	tmtwd: read this also: http://hypirion.com/musings/understanding-persistent-vector-pt-1
23:12	tmtwd	very interesting
23:12	tmtwd	so in a naive implementation of immutability, you would just copy the old version of the data structure?
23:13	devn	that's one way, yeah
23:13	tmtwd	whereas, a better way would be with persistent data structures?
23:14	tmtwd	cool links
23:14	TEttinger	&(let [v [1 2 3] a (int-array [1 2 3])] (do (pr v) (print (vec a)) (print " changing values... ") (map inc v) (amap a i a2 (aset a i (inc (aget a i)))) (pr v) (print (vec a))))
23:14	lazybot	⇒ [1 2 3][1 2 3] changing values... [1 2 3][2 3 4]nil
23:14	devn	tmtwd: i dont want to say categorically better
23:15	devn	like everything, there are tradeoffs
23:15	TEttinger	the map on v won't change v. the map on a actually by default won't, but it can easily
23:15	tmtwd	(conj [1 2 ] 2)
23:15	TEttinger	&(conj [1 2] 2)
23:15	lazybot	⇒ [1 2 2]
23:15	devn	tmtwd: add a , or &to the front of what you just wrote
23:15	tmtwd	&(conj [12 32 44] 4)
23:15	lazybot	⇒ [12 32 44 4]
23:16	tmtwd	cool! I want one
23:16	devn	copy on write collections were added long ago in java
23:16	TEttinger	,(into {} [:a 1 :b 2 :c 3 :d 4 :e 5 :f 6])
23:16	tmtwd	Oh, I already have on
23:16	devn	along with conurrent hash maps
23:16	clojurebot	#error {\n :cause "Don't know how to create ISeq from: clojure.lang.Keyword"\n :via\n [{:type java.lang.IllegalArgumentException\n :message "Don't know how to create ISeq from: clojure.lang.Keyword"\n :at [clojure.lang.RT seqFrom "RT.java" 528]}]\n :trace\n [[clojure.lang.RT seqFrom "RT.java" 528]\n [clojure.lang.RT seq "RT.java" 509]\n [clojure.lang.ATransientMap conj "ATransientMap.java" 4...
23:16	devn	and this was to allow concurrent reads
23:16	devn	but it's only decent to use it when your reads vastly outweight the number of writes
23:17	devn	because it does a copy, with a lock
23:17	TEttinger	,(zipmap [:a :b :c :d :e :f] [1 2 3 4 5 6])
23:17	clojurebot	{:a 1, :b 2, :c 3, :d 4, :e 5, ...}
23:17	devn	so, i have to run, but now we're kind of getting to some important bits for you to understand about clojure
23:17	TEttinger	clojurebot, which is called with comma, will cut off output
23:17	clojurebot	c'est bon!
23:17	TEttinger	&(zipmap [:a :b :c :d :e :f] [1 2 3 4 5 6])
23:17	lazybot	⇒ {:f 6, :e 5, :d 4, :c 3, :b 2, :a 1}
23:17	devn	check out atoms, read up on persistent data structures (the link i posted above)
23:17	justin_smith	~which,
23:17	clojurebot	Huh?
23:17	TEttinger	lazybot will not
23:18	TEttinger	~which
23:18	clojurebot	which is called with comma, will cut off output
23:18	tmtwd	@devn I actually was watching a talk on persistent data structures today
23:18	tmtwd	didn't finish it though
23:19	TEttinger	for certain tasks they're absolutely invaluable, for the rest they're just handy
23:19	devn	they're a sensible default
23:19	devn	IMO
23:19	TEttinger	agreed
23:19	devn	better to have the persistent immutable properties, and then flip them mutable if you need to
23:20	devn	doing it the other way around is a true pain
23:20	tmtwd	good to know
23:20	devn	tmtwd: anyway, like i said, gotta run, but welcome!
23:20	tmtwd	thanks :)
23:21	crocket	Most mutations are bad.
23:21	devn	happy clojuring :)
23:21	crocket	The same applies to genes.
23:21	crocket	Javascript is a mutant ninja.
23:21	justin_smith	turtle with a jetpack
23:22	devn	okay really leaving now
23:22	devn	later all
23:22	justin_smith	is it teenage yet?
23:22	justin_smith	was it made before 1992?
23:23	justin_smith	err wait, people born in 2002 are teenage
23:23	justin_smith	anyway, definitely a teenage mutant ninja turtle
23:24	TEttinger	isn't javascript older than, or approaching, 20 years old?
23:24	tmtwd	TEttinger, today
23:24	tmtwd	it is 20 years old
23:25	TEttinger	wowza
23:40	justin_smith	next year we are gonna have to get javascript soooo wasted
23:47	epichero	javascript already makes me drink...