#clojure – 2015-02-21

2015-02-21

01:56	jux	hi
01:58	jux	I got strange behavior from clojure.java.jdbc. when I do query (sql/query dsn ["select id, name from ns.users where id > ? order by id" 1])
01:59	jux	all strings are returned surrounded by \"
01:59	jux	so I get ({:id 1 :name "\"John Doe\"})
02:00	jux	what can be the reason?
02:03	hiredman	you are double printing, either on the way out or the way in
02:20	jux	hiredman: these things show in my unit tests, so it's not a thing of printing
02:20	jux	and I inserted data directly using Navicat
02:32	jux	hell, you were right
02:47	ewemoa	alexyakushev: having trouble building foreclojure-android -- is it supposed to build atm?
02:48	alexyakushev	ewemoa: What error do you get?
02:52	ewemoa	alexyakushev: https://pastee.org/68hs4
02:53	alexyakushev	ewemoa: Let's take it to #clojure-android, shall we?
03:51	Eremox	Is there some thing like scala's Akka in clojure?
03:52	irctc__	Hi everybody. Is there a shorter version to do this multi arity-function? because for both type of arguments, the same function is called: (defn get-15min-range ([{start :start-time end :end-time}] (range start (+ end 900) 900)) ([start end] (range start (+ end 900) 900)))
03:59	amalloy	irctc__: you can make the first arity call the second one
04:03	irctc__	great, i will to this! I have a second question. when i have two destructuring arguments in a multi-arity function [{a :a b :b}] and [[a b]] - i get a warning that both arguments are the same length, even if one is a map and the other one is a vector. How can i express this destructuring in an multiple-arity function?
04:32	amalloy	you can't. clojure's functions are only overloaded on argument count, not on anything else. if you want different bodies based on something else, oyu need to do more than write a multi-arity function. for example, write a multimethod instead
04:47	the-kenny	Or you can use core.match if you want the 'matching' style.
04:48	irctc__	i will look into core.match and multimethods - thanks for the advice
05:49	nw2	probably a stupid question, but in this example https://www.refheap.com/97610, the call to the "foo" macro throws a ClassNotFoundException, but the "bar" macro works fine. is there any way to make the "foo" macro work?
05:51	Bronsa	nw2: you want & body not body in the argvec
05:52	hyPiRion	(macroexpand-1 '(foo (File. "/tmp"))) => (do File. "/tmp")
05:53	nw2	Bronsa: ah, of course! thank you very much
06:19	Guthur`	Hi, I'm just starting with Clojure usign Emacs and CIDER
06:19	Guthur`	I was wondering if there is an eldoc style hint system with CIDER
06:20	Guthur`	so that I can get information about the interface for a function etc
06:20	Eremox	Why is sicp recommended?
06:21	AimHere	Partly because it introduces a lot of important programming concepts. Also it uses a lisp as it's introductory programming language, which turns some nerds on.
06:22	darrenh	I have a question about the component framework. If I want to vary a protocol implementation based on configuration, is there a good way to go about it? My use case is where I want to wrap one of my components with one that intercepts the calls based on a configuration flag.
06:22	Eremox	Which would be better to read first sicp or ctmcp
06:42	tomjack	Guthur`: yes? it doesn't work for you?
06:42	tomjack	oh, it looks like I had to do (require 'cider-eldoc) (add-hook 'cider-mode-hook (lambda () (cider-turn-on-eldoc-mode)))
06:48	Guthur`	tomjack: ah, ok I will give that ago
06:53	Guthur`	tomjack: excellent,thanks
06:54	tomjack	if you use paredit, I'm not sure it works right
06:54	tomjack	http://emacswiki.org/emacs/ParEdit#toc2
06:55	tomjack	but it seems kind of nuts that only those two commands are on the list!
07:01	Guthur`	Yeah i normally use paredit, but have not added it to a clojure mode hook yet
08:17	jaen	Is there any way to dump leiningen middleware stack and/or hooks so I know where certain behaviour comes from (or a verbose execution mode that says so)?
08:44	the-kenny	jaen: with lein pprint, yes.
08:44	the-kenny	jaen: https://github.com/technomancy/leiningen/tree/master/lein-pprint
08:51	jaen	the-kenny: thanks. It shows no middleware however. That's weird o_0
09:13	doright	Clojure appears in only 17 London job titles on www.indeed.co.uk compared with Scala:386 and Groovy:70. What is required to increase Clojure's adoption?
09:13	pandeiro	what would be the way to walk a sequence of nested sexps and produce a sequence of all of them, eg: (f '((foo (bar baz)))) => ((foo (bar baz)) (bar baz))
09:15	the-kenny	pandeiro: check clojure.walk
09:16	the-kenny	doright: My guess is recruiters write scala on their job offers because it's sooooo enterprise.
09:16	doright	10 of these jobs include other languages in the title so 7 are exclusively Clojure, cf. Scala:297 and Groovy:42
09:16	pandeiro	the-kenny: yeah i don't see how to accumulate the result w/ walk
09:16	pandeiro	the-kenny: aside from using them for side effects w/ an atom
09:18	the-kenny	pandeiro: hm. clojure.core/tree-seq then maybe?
09:19	the-kenny	,(rest (tree-seq sequential? seq '((foo (bar baz)))))
09:19	clojurebot	((foo (bar baz)) foo (bar baz) bar baz)
09:21	the-kenny	now throw away non-lists and bingo
09:21	pandeiro	the-kenny: nice, thank you
09:22	irctc__	Hi everybody. How can i union a seq/list of sets? (union '(#{1}) #{1})
09:22	irctc__	sorry... like this one (union '(#{1} #{1})
09:22	the-kenny	,(apply union [#{42 23} {1 2 3 42}])
09:22	clojurebot	#<CompilerException java.lang.RuntimeException: Unable to resolve symbol: union in this context, compiling:(NO_SOURCE_PATH:0:0)>
09:22	the-kenny	,(apply clojure.set/union [#{42 23} {1 2 3 42}])
09:22	clojurebot	#<CompilerException java.lang.ClassNotFoundException: clojure.set, compiling:(NO_SOURCE_PATH:0:0)>
09:23	the-kenny	damn you clojurebot
09:23	AimHere	,(apply clojure.set/union [#{42 23} #{1 2 3 42}])
09:23	clojurebot	#<CompilerException java.lang.ClassNotFoundException: clojure.set, compiling:(NO_SOURCE_PATH:0:0)>
09:23	irctc__	great! thanks!
09:23	the-kenny	irctc__: either apply or reduce, a matter of taste. I prefer reduce when the size of the input list is unknown.
09:25	the-kenny	AimHere: whoops, just noticed the missing # in my code.
09:26	AimHere	Didn't do much good, as far as clojurebot was concerned
09:27	the-kenny	yeah, no difference here.
09:29	vas	,(apply hash-map [:a 5 :b 6])
09:29	clojurebot	{:b 6, :a 5}
09:29	vas	,(reduce hash-map [:a 5 :b 6])
09:29	clojurebot	{{{:a 5} :b} 6}
09:29	the-kenny	it doesn't work for all functions, that's obvious
09:52	hyPiRion	If you have a function on the form (fn f ([a] (f a init-val)) ([a b] ...)), is it more idiomatic to put the `b` arg at the end or in the front?
09:52	hyPiRion	Assuming that people are unlikely to use the two-ary version on a daily basis
09:56	seancorfield	hyPiRion: I think I would expect ((f x) y) == (f x y) so b should be at the end... But I know there are sometimes good reasons for not doing that (I think there are core fns like that?).
09:59	hyPiRion	seancorfield: yeah, the sort-functions in core is probably doing that to keep the coll at the end like map and friend does
09:59	hyPiRion	It won't be used in that setting though, so I guess it makes more sense to just put it at the end
10:02	seancorfield	Yeah, the "coll arg last" idiom is a good reason for ((f x) y) to be (f y x) :)
10:16	ambrosebs	how do I tell lein which project.clj to use without cd'ing into it?
10:16	ambrosebs	I want to run the tests of some subfolder in a Makefile
10:18	Glenjamin	sh -c "cd subfolder && lein test" ?
10:18	Glenjamin	not really what you asked, but should work
10:20	ambrosebs	Glenjamin: thanks :)
11:02	zling	earnestly
11:14	justin_smith	doright: maybe not be a lisp?
11:15	justin_smith	ambrosebs: you can use cd in make commands
11:15	justin_smith	I typically use a pushd / popd combo though
12:14	Guest40845	Hey there, off topic question but can I PM someone who has experience leaving a software project written by a very small team or you're the only guy on the team? Trying to make a career move and I don't want to hurt the company I'm with…
12:33	justin_smith	Guest40845: I've done a handoff before. Leave detailed comments describing what each file is for, and add an overview tying all of them together in the README. Also, be sure that the README has a description of how to build, run, deploy that can be followed by the letter without any implicit steps
12:41	Guest40845	justin_smith: mind if i pm?
12:43	justin_smith	go ahead, sure
13:02	dnolen	ClojureScript 0.0-2913 released, Google Closure Modules, and better underlying architecture for supporting nREPL https://groups.google.com/d/msg/clojurescript/n_8WHnlcOGI/1kmATGABVi0J
14:19	underplank	Hi all im trying to instansiate a java ProcessBuilder class like so
14:19	underplank	orochi.core.api=> (ProcessBuilder. 'python')
14:19	underplank	IllegalArgumentException No matching ctor found for class java.lang.ProcessBuilder clojure.lang.Reflector.invokeConstructor (Reflector.java:183)
14:19	underplank	Any idea why?
14:21	underplank	apparently it doesnt have a constructor? or something?
14:25	i-blis	underplank: try (ProcessBuilder. (list "python"))
14:25	kriyative	@underplank -- did you mean "python" with double-quotes?
14:25	underplank	I meant a string of “python”
14:25	i-blis	underplank: the constructor takes a list
14:26	underplank	i-blis: huh. it also looks like it take a string. but, thats cool. I could be looking at an old api
14:26	underplank	yup. using a list works. thanks!
14:27	i-blis	:)
14:27	underplank	yeah I should look at the version of the docs I am looking at. Apparently back in Java 1.5 you could ue a string.
14:27	underplank	:)
14:28	underplank	thanks i-blis !
14:31	csd_	Are any of you running CIDER 0.9.0-snapshot?
14:32	i-blis	you're welcome underplank
14:34	i-blis	csd_: went back to 0.8.2 a week or so ago : did jack in but did not eval code
14:34	csd_	i-blis: i can't jack in.. gives me a class path error
14:35	i-blis	csd_: use stable :)
14:35	csd_	yeah :-/
14:35	justin_smith	underplank: ProcessBuilder takes either varargs string, or list of string. It turns out that via clojure you need to provide either a list, or a String-array because varargs are a java compiler thing and don't exist on a vm level
14:36	i-blis	csd_: or do you absolutely need boot support?
14:36	underplank	ahhh, right. that makes sense. So when they say “String” in the constructor, thats not actually what that means :)
14:36	csd_	i had been using the snapshot for a while because of a bug i'd run into a while back
14:37	csd_	its just sort of annoying because i get packages from the "non-stable" branch of MELPA but this is the one thing ill have to have to get from the stable branch
14:37	i-blis	0.8.2 seems pretty stable
14:38	i-blis	csd_: you can pin the package
14:38	vas	so I end up with some enlive vectors that look like: [{nodes}] and [{nodes}] .... how do you combine two vectors? (am i right in calling them vectors because they're in square brackets?)
14:38	csd_	i-blis: awesome
14:38	vas	( ideal result is just sequential [{nodes}, {nodes}] )
14:39	kriyative	i-blis: how do you pin packages from MELPA? I switched to el-get just for that ability.
14:39	i-blis	csd_: (add-to-list 'package-pinned-packages '(cider . "melpa-stable") t)
14:40	kriyative	i-blis: good to know, thanks.
14:41	i-blis	csd_: provided you added melpa-stable to packages-archives, igws
14:44	vas	huzzah for concat.
14:46	csd_	i-blis: looks like MELPA-stable has 0.7.0 latest
14:48	i-blis	csd_: are you sure you're using stable.melpa.org?
14:48	csd_	positive
14:48	i-blis	http://stable.melpa.org/#/cider has 0.8.2
14:48	csd_	weird, thats not what Packages shows
14:49	i-blis	csd_: emacs 24?
14:49	csd_	no, 25
14:49	i-blis	well, shouldn't be the issue
14:50	csd_	oh wait i think i have a syntax in my emacs config
14:50	csd_	err a syntax error
14:51	i-blis	do you have : (add-to-list 'package-archives
14:51	i-blis	'("melpa-stable" . "http://stable.melpa.org/packages/") t)
14:52	csd_	i-blis: there we go :)
14:52	csd_	thank you
14:53	i-blis	csd_: you're welcome
14:54	csd_	one of those times where you go to do some work and unexpectedly waste a half hour tooling :-/
14:56	gfredericks	does anybody know how to throw this exception via normal clojure usage (i.e., without interopping in the Var class)?
14:56	gfredericks	https://github.com/clojure/clojure/blob/master/src/jvm/clojure/lang/Var.java#L218
15:05	i-blis	gfredericks, why not: (throw (java.lang.IllegalStateException.))
15:12	gfredericks	i-blis: I'm more asking about how to get to that line of code
15:12	gfredericks	I want to know if it's even possible
15:15	amalloy	gfredericks: (binding [x 1] (.start (Thread. #(set! x 2)))) maybe?
15:17	i-blis	gfredericks: I am not sure I understand, you want to throw an exception as if a var was set outside its thread?
15:18	gfredericks	amalloy: if it's not bound on the new thread then you'll just get a normal can't-set!-a-var-without-a-thread-local-binding
15:18	gfredericks	i-blis: yep; based on my understanding that line should be unreachable, trying to figure out if there's anything I'm missing
15:27	justin_smith	gfredericks: is it that you got that exception and want to know how it could have happened?
15:27	kryft	What would be the best way to ensure that a function can't be called if a call to that function is currently in progress? So basically a simple lock
15:28	justin_smith	kryft: wrap the function body in a call to locking?
15:29	justin_smith	,(defn locked [x] (locking locked (inc x)))
15:29	clojurebot	#'sandbox/locked
15:29	justin_smith	it locks on itself
15:29	justin_smith	,(locked 1)
15:29	clojurebot	2
15:29	kryft	justin_smith: Ok, that seemed to be the solution based on some quick googling, but it was usually accompanied by "you should rarely need to use locking" :)
15:29	kryft	justin_smith: So I thought I'd check that there isn't a more idiomatic way
15:29	justin_smith	kryft: well, why is it that the function needs to be locked?
15:29	justin_smith	the more idiomatic way is not to need locking at all :)
15:29	amalloy	kryft: well indeed you should rarely need to do this
15:30	justin_smith	kryft: usually we use immutable data structures so that locking is irrelevant
15:30	gfredericks	justin_smith: nope have never got it as far as I know
15:30	gfredericks	just wondering if it's dead code or not
15:30	justin_smith	gfredericks: ahh, I misunderstood then
15:30	justin_smith	OK
15:31	justin_smith	kryft: amalloy: of course when interacting with an external system we sometimes lose some of the tidiness that immutability offers, and locking is sometimes needed
15:32	justin_smith	kryft: but for example if your algorithm assumes locking and is 100% clojure, there is probably a nice immutable lock-free way to do it
15:32	kryft	justin_smith: Well, my app sends emails every now and then, and it keeps emails in a postgresql DB (with a lot of other data). The function in question fetches unsent emails and tries to send them.
15:32	justin_smith	and the locking is because you don't want emails sent more than once?
15:32	kryft	justin_smith: Right.
15:32	amalloy	kryft: well you have a whole database to work with! databases are great at lokcing
15:33	justin_smith	kryft: clojure doesn't have implicit paralellism - if you don't do the task from multiple threads or instances, you won't need to worry about that
15:33	amalloy	add a column "trying_to_send_right_now", and set that to true when you take it out, for example
15:33	amalloy	locking will only work inside one jvm, but if you put the lock in the database it will scale to any number of servers later on
15:34	justin_smith	that's a good point too, but I still think it's easier to just ensure that only one thread in one instance is email sending. It's not as if email sending is a bottleneck that you need to parallelize for performance in most cases.
15:36	kryft	justin_smith: Currently the sending could be triggered from multiple threads - basically I try to send as soon as I add a new email to the table. The table is there mostly to keep track of what's been sent and because it's naturally possible that sending could fail.
15:37	justin_smith	kryft: OK. My approach would be to have a single thread responsible for sending emails, perhaps offering a queue that other threads could put emailing tasks onto.
15:38	justin_smith	kryft: though perhaps there is some other factor that makes emailing from arbitrary contexts advantageous?
15:39	kryft	justin_smith: Not really - I just want to make sure they get sent relatively quickly (for example, a user registers and gets a confirmation immediately)
15:39	justin_smith	in general I find if something needs to be done exactly once, having exactly one thread in charge of it is helpful
15:39	kryft	justin_smith: So I'm sure a single thread would work.
15:40	justin_smith	you could also use core.async instead of a thread and a queue, if you find other places where core.async would be useful
15:40	justin_smith	anyway, this eliminates the need for locking logic, because that single thread of execution (or logical thread of execution in the core.async case) can reliably track what has and hasn't been done
15:41	justin_smith	since it is syncronous in its own context
15:42	kryft	justin_smith: Right, sounds good. It didn't occur to me to have an explicit thread for that.
15:43	kryft	amalloy: I considered using the DB for this, but I wasn't sure that it could be done without using DB locks (which clojure's jdbc interface doesn't seem to support)
15:43	justin_smith	another (mostly equivalent) option is to use an agent, and store the emailed addresses in the agents, sending it a function that sends an email if it hasn't been sent yet
15:44	justin_smith	s/agents/agent
15:44	kryft	amalloy: (I'm fairly new to postgresql too, so I may well be mistaken :)
15:44	kryft	It's my first backend, my first DB application, and my first clojure app! :P
15:44	justin_smith	best of luck!
15:49	kryft	justin_smith: Thanks!
16:05	kryft	justin_smith: For the "single responsible thread" approach, did you mean having a function regularly polling the queue and sending emails whenever there's something in there, or something fancier?
16:05	justin_smith	kryft: no need to poll even, just blocking read on the queue in a loop
16:07	kryft	justin_smith: Ah, right
16:07	justin_smith	kryft: so, if you use java.util.concurrent.BlockingQueue it would be a .take operation
16:07	justin_smith	(rather than .poll, which has a timeout)
16:09	justin_smith	and then .put for synchronous adding to the queue (but not synchronous waiting for it to be consumed)
16:14	kryft	justin_smith: Ah, nice (I was trying to find a structure like that in clojure)
16:14	justin_smith	kryft: there is clojure.lang.PersistentQueue
16:15	justin_smith	,(let [q clojure.lang.PersietentQueue/EMPTY q' (conj q :a)] (into [] q'))
16:15	clojurebot	#<CompilerException java.lang.ClassNotFoundException: clojure.lang.PersietentQueue, compiling:(NO_SOURCE_PATH:0:0)>
16:15	justin_smith	oops
16:15	justin_smith	,(let [q clojure.lang.PersistentQueue/EMPTY q' (conj q :a)] (into [] q'))
16:15	clojurebot	[:a]
16:15	justin_smith	but in that case you would want to put it inside an atom, ref, or agent
16:16	kryft	Right
16:18	kryft	justin_smith: Thanks again; I guess I'll just use a BlockingQueue here, but good to know that PersistentQueue exists
16:19	justin_smith	also, as I mentioned before, core.async is a mini language around channels, that are effectively queues
16:19	justin_smith	but it may be a bit much if you only need that kind of flow in one place
16:24	kryft	justin_smith: Yeah, that's probably overkill here; all other concurrency issues are basically handled by JDBC transactions. Also core.async seems to be in alpha at the moment?
16:37	justin_smith	kryft: alpha, but widely used
16:38	kryft	justin_smith: A bit like prismatic/schema then :P
16:42	justin_smith	I think it's wider deployed than schema though, I've had it in production a couple of instances myself
16:42	Graawr	hey ! is there a "pure clojure" (i.e. without wobbly java interop) way to extract a directory from the currently running jar ? I'm currently coming up with a direct translation of a java snippet using JarFIle & JarEntry, but it really feels wobbly
16:43	justin_smith	Graawr: in general, clojure core doesn't abstract very far from the host for IO stuff. That lib may exist out there somewhere though.
16:44	csd_	can someone please look at this core.async snippet and tell me what i'm missing? i would expect 42 to be printed https://www.refheap.com/97625
16:48	Graawr	justin_smith: okay, so I better keep going then. I'm translating this answer ( http://stackoverflow.com/questions/1529611/how-to-write-a-java-program-which-can-extract-a-jar-file-and-store-its-data-in-s/1529707#1529707 ) to clojure, although I'm lost at getting an input stream : (.getInputStream (jar-file jar-entry)) always returns nil
16:50	justin_smith	and jar-file is a java.util.jar.JarFile?
16:50	Graawr	yup
16:50	Graawr	and jar-entry is a java.util.jar.JarEntry
16:50	justin_smith	oh, the code there calls getInputStream on jar-file
16:51	justin_smith	not on the entry
16:51	justin_smith	err wait
16:52	Graawr	whoops, typo: (.getInputStream jar-file jar-entry) returns nil (there's no nesting)
16:52	justin_smith	so, I would expect this to work: (.getInputStream (java.util.jar.JarFile. "some/path/to.jar"))
16:52	justin_smith	why the extra arg?
16:52	justin_smith	the stream is the jar, not some entry in the jar
16:52	justin_smith	wait...
16:53	justin_smith	ok, so file is a java.io.File
16:53	justin_smith	you get an inputstream from the file
16:54	justin_smith	sorry, I'm all mixed up on this, I'm backing out for a moment
16:54	Graawr	oh okay, thank you !
17:00	justin_smith	Graawr: my java is rusty - would the continue in that first if statement skip the rest of the body and start the next step of the while loop?
17:01	justin_smith	because if the first thing you got was a directory, I could see getInputStream returning nil if you did not replicate the continue logic
17:01	maacl	Help oh help, just upgraded my emacs packages and now I don't get a repl buffer when I do cider-jack-in or cider-connect
17:02	justin_smith	maacl: delete your elc files and restart emacs
17:02	justin_smith	cider tends to not upgrade cleanly
17:03	Graawr	justin_smith: yes, the continue will skip the current loop interation
17:03	maacl	justin_smith: Ok, will give that a try.
17:04	Graawr	justin_smith: but I get a nil from getInputStream whatever the input (file or directory jarEntry)
17:08	maacl	justin_smith: Thanks, that did the trick.
17:08	clojurebot	Huh?
17:08	justin_smith	maacl: np, it should really be in the cider docs
17:11	justin_smith	Graawr: so I made my own attempt to translate it, mostly just to help me read it
17:12	justin_smith	Graawr: the error I run into is that I get entries that belong in a specific directory, but not an entry representing the directory itself
17:12	justin_smith	(so of course it can't write to it, the directory has not been made yet)
17:13	justin_smith	Graawr: d'oh, and now I read the comments!
17:14	justin_smith	Graawr: would it be instructive to show you my translation that works, or would you rather sort it out yourself?
17:14	Graawr	justin_smith: I'd like to see your version if that's okay, I'm still a bit struggling halway through mine
17:15	justin_smith	of course I had to pick a jar that had more than 2800 files in it to test with...
17:15	justin_smith	OK
17:16	justin_smith	Graawr: this is a direct translation (taking into account the comments about .getParentFile) and it works https://www.refheap.com/97626
17:16	Graawr	justin_smith: although I believe that fixing the fault reported in the comments shouln't be hard with raynes fs utilities, IIRC there's a function to make parents dirs if they don't exist
17:16	justin_smith	no need for any libs for this
17:16	justin_smith	getParentFiles is trivial
17:16	justin_smith	*getParentFile
17:16	Graawr	oh right
17:17	justin_smith	also, I changed the system separator to "/" because that works even on Windows
17:17	Graawr	ah, didn't know that
17:17	Graawr	hum
17:17	Graawr	I see you don't use enumeration-seq on the entries ? I thought it was needed
17:17	justin_smith	and I am quite reluctant to use system separator (perhaps superstitiously) after dealing with network code that tried to put system separator in a URL
17:18	justin_smith	Graawr: that's not a call, that's just a type
17:18	justin_smith	err... wait
17:18	justin_smith	why would I need enumeration-seq?
17:19	Graawr	nevermind, that was an artefact from a previous try where I got confused by the Enumeration class used
17:19	justin_smith	Graawr: oh, I get it. Since I am not using clojure sequence functions, I don't need to use enumeration-seq.
17:20	Graawr	yup
17:20	justin_smith	I directly converted the while into a while, instead of making it a doseq over a seq - which could have been cleaner, but I was in "zero brain translation" rote mode
17:20	Graawr	though if I wanted to use seq (like using a loop/recur with (first ...) and (rest ...)) it would be needed right ?
17:20	justin_smith	Graawr: I wouldn't use loop/recur - enumeration-seq + doseq
17:21	Graawr	oh
17:21	justin_smith	loop / recur with first / rest can almost always be translated into something higher level
17:24	Graawr	hum, yes, i've still not really wrapped my mind around higher-level looping structure besides map/reduce kinds
17:24	justin_smith	Graawr: you might find it a nice exercise to translate the while into a doseq / enumeration-seq combo, and/or replacing the innermost let with a with-open call on the two streams
17:26	Graawr	that's exactly what i'm experiencing ^^
17:28	Graawr	by the way, as I'm extracting from a running jar, I use the (-> (class ns) .getProtectionDomain .getCodeSource .getLocation .getPath) to get the path of the running jar, but it, here again, seems a bit wobbly. Isn't there any standard tool to reference the running jar ?
17:28	justin_smith	also, I bet it could be at least 10x as fast if you added a byte-array for read, instead of reading one byte at a time
17:28	justin_smith	Graawr: what you have there is how I would do it
17:28	justin_smith	Graawr: what's the end goal? do you need the files to be on disk to use some OS utility on them?
17:28	Graawr	hum, I have to say my java IO was fairly brief, I might need to look further into bytes array for writing
17:29	justin_smith	Graawr: it's an alternate read method, takes a byte array for filling
17:29	justin_smith	and then of course instead of writing one byte, you would write as many bytes from the array as you read (the return value of read will tell you how many)
17:30	justin_smith	and write, of course, has an alternate method that takes a byte-array to write from
17:31	Graawr	justin_smith: no, i'm building a transcompiler for a school project; I convert a directory structure containing notes took in a given language into a local, static website, so I need to copy the default assets (in jar at runtime) to disk
17:32	Raynes	People keep telling me to rewrite refheap in node.
17:32	justin_smith	Graawr: OK, you may or may not be aware that we can use clojure.java.io/resource to get file contents from a jar without writing anything to disk
17:32	Raynes	I'm incredibly entertained by this, given that the one single lone reason for folks using refheap is because it's written in Clojure
17:32	Raynes	Because everyone has it in their head that "Hey, I can contribute to this in my favorite language!"
17:33	Raynes	But then they never contribute to it.
17:33	justin_smith	Raynes: nah, I use it because it isn't spammy and it syntax highlights with a dark background
17:33	Raynes	I need to rewrite it
17:33	rhg135	nah, same here
17:33	Raynes	Not in node, but in Clojure.
17:33	Graawr	justin_smith: yes, but as I generate a static site, some assets (js, fonts, css) need to be on disk for the final "product" to be used by the end user
17:33	Raynes	justin_smith: So I should revert this commit to add interstitials?
17:33	justin_smith	Graawr: aha, so you aren't serving the stuff from a clojure web server
17:33	justin_smith	Raynes: DON"T YOU FUCKING JOKE
17:33	justin_smith	haha
17:34	Raynes	git branch -D piss-off-justin-smith
17:34	Raynes	gf3: We should rewrite refheap from the ground up with you designing.
17:34	Graawr	justin_smith: no, that's entirely local. The point is just to pass a lectures notes directory to the software, and it spits back a static site
17:34	Raynes	We'll use Graawr's static site generator.
17:34	Raynes	We'll just regenerate it every time someone makes a paste.
17:35	justin_smith	Graawr: ahh, got it
17:35	Raynes	In all seriousness, it might be fun to rewrite the whole thing with cljs
17:35	Raynes	Client side 4evr
17:35	justin_smith	http://i.imgur.com/aJwbNM4.jpg
17:36	Raynes	yes
17:36	rhg135	Raynes, how would the api work if it ran client-side?
17:36	Raynes	How would anything work fi it ran client side?
17:36	Raynes	There'd still be a server component.
17:37	justin_smith	rhg135: the one benefit I can think of is it could push edits when people update the paste
17:37	Raynes	But the server would probably just become an API service.
17:37	justin_smith	perhaps even a UI to see revisions
17:37	rhg135	ah ok, and that'd stay the same i assume?
17:37	Raynes	The API is shitty, so I'd probably change it too
17:37	rhg135	i find it pretty simple
17:37	Raynes	I can add a compatibility layer :P
17:38	rhg135	GET to /posts/:id get response
17:38	Raynes	Oh, that'd still work
17:39	rhg135	i'm curious what you mean by a new api.
17:40	rhg135	justin_smith, push is always win imo in web design
17:40	Raynes	rhg135: I mean, the problem with the current API is not really the API itself, but how it's written
17:40	Raynes	See, I didn't know a damn thing about web development.
17:40	Raynes	The API is entirely distinct from the interface.
17:40	Raynes	They hardly even use the same code
17:40	Raynes	It's so ridiculous.
17:40	Raynes	The web interface should be using the same API
17:41	rhg135	oh I see, Raynes. So maybe some feature expressions if you go cljs?
17:41	Raynes	'feature expressions'?
17:41	Raynes	Maybe I still don't know shit about web development.
17:41	Raynes	Damn it.
17:41	Raynes	I need to stop writing websites
17:41	Raynes	;)
17:42	rhg135	being able to share code server-side with client-side
17:42	Raynes	I see
17:42	Raynes	I don't know what state of the art in cljs client-server communication is
17:42	Raynes	But I hope there is some good shit available
17:42	Raynes	I'm spoiled by Meteor
17:42	Raynes	Where it's all so seamless
17:42	justin_smith	Raynes: feature-expressions are all liek "this code only works in js" "this other code only works in the jvm" but it's all still in one file
17:42	rhg135	websockets i hear are useful for this
17:43	Raynes	Yeah, websockets are the answer but I don't want to deal with them directly. I imagine there's a bunch of cljs stuff that already deals with htis.
17:43	Raynes	If not, I'll come back in a few months when there is :P
17:43	rhg135	or even ajax
17:43	Raynes	http://hoplon.io/
17:43	Raynes	Like this
17:44	rhg135	the goal is to minimize the synchronization from client to server
17:45	Raynes	It should all be pretty simple
17:46	rhg135	i don't do any web dev either
17:46	Raynes	I do web dev, but usually single page apps.
17:46	rhg135	but i've read being able to share code--like nodejs--is a boon
17:47	rhg135	so clj(s) is nice
17:47	Raynes	I've been doing a lot of ES6/Coffee lately.
17:47	Raynes	I don't share the same furious hatred for JS that others do.
17:48	rhg135	i've done Coffee just because i cba to remember js's quirks
17:48	justin_smith	shall we burn the heretic, stone him, or simply force him to live with his corrupted and sad decisions?
17:48	Raynes	I mean, coffee shares those quirks.
17:48	rhg135	it's a fine language if you know it, and I don't
17:49	Raynes	Coffee is just a js preprocessor, really.
17:49	rhg135	Raynes, but less
17:49	Raynes	ES6 is pretty cool too
17:49	rhg135	it is which is great
17:49	justin_smith	rhg135: it was written in like a week, you can learn the important aspects in less time than that
17:49	Raynes	I'm furious they didn't add a thin arrow with their fat arrow.
17:49	rhg135	ive been out of the js loop since before es6 existed
17:49	rhg135	well it did just not practically
17:50	rhg135	justin_smith, i could, it's the context switches in my mind I'd have to make going back to another lang
17:51	Raynes	ES6 offers: a module system, => fat arrow functions that pass the this context in, potentially comprehensions...
17:52	rhg135	i didn't feel like running a development nodejs build
17:52	Raynes	babeljs.io
17:52	rhg135	or using that lol
17:52	Raynes	https://github.com/Raynes/barrelroll
17:53	Raynes	Currently writing a thing with it
17:55	Raynes	oshi
17:55	Raynes	There's a new Clojure build tool?
17:55	rhg135	why be afraid?
17:56	justin_smith	I don't know how mature boot is
17:56	rhg135	not like they can't speak to each other
17:56	rhg135	they both produce jars
17:59	Raynes	I wrote small very small portions of leiningen
17:59	Raynes	I'm emotionally attached
17:59	rhg135	i like leiningen; it makes it easy for clj
17:59	rhg135	cljs otoh is a pita
18:12	thsig	Hey guys, I'm about to start a web app project which I expect will eventually be quite full-featured - do people here prefer ring or pedestal or something else for such cases? Is ring mostly preferred for smaller apps, or is it most popular in general?
18:13	thsig	I.e. is ring preferred for smaller, simpler apps, and are other methods preferred for bigger/more complex apps? Or is it a good fit for the whole spectrum?
18:16	justin_smith	thsig: unless you have a really compelling reason, ring is the best bet
18:16	justin_smith	almost everything else (with rare exceptions like pedastal) uses ring
18:18	thsig	justin_smith: Thanks for the feedback! I'm coming at this from ruby land, having mostly used clojure for non-web stuff, so I was wondering how apt the analogy "ring ~ sinatra" was.
18:18	thsig	since in ruby, one ends up adding a lot of the stuff from rails back on to sinatra as the requirements get more complex
18:19	justin_smith	thsig: I wouldn't compare ring to sinatra, no
18:19	thsig	but of course clojure is different, just trying to get a feel for the web library landscape
18:20	justin_smith	thsig: if anything I would compare compojure to sinatra, but in the clojure world we tend to do things very modular
18:20	justin_smith	you can easily use ring without compojure
18:21	thsig	justin_smith: Ok, I see. I guess ring is more like rack.
18:21	thsig	there's a lot of stuff that comes along with rails that I've never used or liked
18:21	justin_smith	yeah, that's a much closer comparison
18:21	thsig	and now that I'm experienced I like the idea of picking just what I need
18:21	justin_smith	yeah, that's the norm in clojure
18:23	thsig	justin_smith: Thanks again for responding, I'll keep working through my checklist of libs that I need - looks like the ecosystem is pretty solid these days.
18:24	justin_smith	in my experience you can start with the libs you need for your basic functionality, and add more as you need them. We don't really do "frameworks" that demand you structure your entire app differently, for the most part
18:25	justin_smith	heh
18:28	gfredericks	,(def a-million (bit-shift-left 20 1))
18:28	clojurebot	#'sandbox/a-million
18:29	justin_smith	,a-million
18:29	clojurebot	40
18:34	underplank	So im using stuart Sierras component for an compojure app. I dont need to store any state durably (ie db or anything). And I need to access the state in each ring handler. So I’ve manged to pass the component defrecord into the handler, but of course when I update it I get a new version and need to somehow return the new value of the component.
18:34	underplank	example code https://www.refheap.com/97630
18:37	justin_smith	so every time a client hits create-proxy you would rebuild your whole system? that seems a bit silly
18:38	justin_smith	why not update an atom containing proxies?
18:39	justin_smith	otherwise you have a topological problem, as you've noticed, where the handler that creates your response also wants to return a new component
18:39	underplank	Sorry. the code is slightly wrong. So I have an Api component. And a Controller component. the controller component sits inside the Api component. When I add a proxy its supposed to add to the Controller component
18:40	underplank	I was thinking that the reference to the Controller component inside the Api Component needs to be an atom? and then I can update that at will.
18:40	underplank	and the Api component doesnt need to be replaced.
18:40	justin_smith	right. Or you can do something more convoluted where you both return the response and the potentially updated component, and then sort out that logic at a higher level of the code
18:41	justin_smith	but that seems like it would get a little messy without much benefit
18:43	underplank	yeah. I think I had already put in place the seperation of the API which is just poking the controller. So atom in the Api it is. thanks justin_smith !
20:11	maacl`	Does anyone know if it is possible to get popup documentation with CIDER and company completion?
20:13	justin_smith	yes, it is possible
20:14	arrdem	supposedly it'll "just work" if you have company turned on
20:14	arrdem	hasn't worked for me in a while
20:14	justin_smith	that was my experience a while back, but I wouldn't be surprised if something broke at aome point
20:14	maacl`	justin_smith: Ok, is there anything I have to do to enable it? Completion works, but I am not getting any documentation
20:15	justin_smith	I'm not really sure, I just know I have had it working in the past
20:15	maacl`	justin_smith: ok
20:16	arrdem	#clojure-emacs may be able to help, but that's a pretty quiet channel. If it isn't in the CIDER docs, it's presumed to "just work" and you should probably open a ticket.
20:22	maacl`	arrdem: Thanks, I have raised a ticket.
20:23	arrdem	clojurebot: rejoice
20:23	arrdem	maacl`: thanks.
20:23	arrdem	maacl`: FWIW cider-grimoire still totally works, not that I'm biased or anything :P
20:55	doright	How do I convert, for example, "String" to a parameter of the (class ....) function?
20:55	arrdem	doright: what are you trying to achieve? resolve the class named by a string?
20:56	doright	arrdem: (defn get-meths [class-name] (for [meth (.getDeclaredMethods (class class-name))] (println (.getName meth))))
20:56	doright	(defn get-meths [class-name] (for [meth (.getDeclaredMethods (class class-name))] (println (.getName meth))))
20:57	doright	arrdem: With (import 'java.lang.reflect.Method)
20:58	Bronsa	doright: given that you call (class ) on class-name you're going to need an instance object of that class
21:02	doright	Bronsa: Not really. This works: (let [mths (.getDeclaredMethods (class String))] (for [m mths] (println (.getName m))))
21:02	Bronsa	,(class String)
21:02	clojurebot	java.lang.Class
21:02	Bronsa	doright: that's likely not what you want
21:03	doright	Bronsa: Why? It lists all the methods, like I asked.
21:03	Bronsa	doright: it lists all the methods of Class not String
21:04	doright	Bronsa: Ah, will have another look :)
21:04	arrdem	I'll leave you in Bronsa's more classloader-informed hands
21:04	Bronsa	doright: what is exactly that you want get-methods to do?
21:05	Bronsa	get-meths, rather
21:06	doright	Bronsa: Should have been: (let [mths (.getDeclaredMethods (class (String.)))] (for [m mths] (println (.getName m))))
21:07	Bronsa	doright: what's the input to your function and what's the desired output?
21:07	doright	Bronsa: I don't think it's do-able but pass in a class name such as String or URL.
21:08	Bronsa	doright: as a string?
21:08	doright	Bronsa: (class (classname.)) [pseudo-code] looks even less likely
21:08	doright	Bronsa: Yes, as a string.
21:09	doright	Bronsa: S'pose core.typed might come in handy here.
21:10	doright	Bronsa: I'm just playing with Java interop, that's all, as a learning exercise.
21:11	Bronsa	doright: this is how it should be written then: http://sprunge.us/BUGY?clj
21:11	doright	Bronsa: There's a long-winded Java example of getting all the methods of a class so thought I'd have a go in Clojure.
21:12	doright	Bronsa: Marvelous. I'll go study that one. Thanks.
21:12	Bronsa	doright: that assumes your class-name string represents either an imported class or a fully qualified class name. Not sure why you can't just pass the class directly but that's how to do it with a string
21:12	Bronsa	doright: also note that for is lazy, when you need to perform side-effects you should use doseq
21:15	doright	Bronsa: (symbol "class-name-string") was what I needed.
21:16	Bronsa	doright: not really, (symbol "String") returns 'String as a symbol, not the String class
21:16	Bronsa	,(class (symbol "String"))
21:16	clojurebot	clojure.lang.Symbol
21:16	doright	Bronsa: Maybe I could have passed it directly after all.
21:16	Bronsa	,(class String)
21:16	clojurebot	java.lang.Class
21:16	Bronsa	doright: in that case http://sprunge.us/cOTN?clj and you can invoke it as (get-meths String)
21:19	doright	Bronsa: ^Class is a type hint?
21:19	Bronsa	yes
21:19	doright	Bronsa: Then that's what I was missing. Learned a lot, thanks.
21:20	Bronsa	doright: note that type hints only affect performances, they don't change the semantics of the code
22:40	justin_smith	,(Class/forName "String")
22:40	clojurebot	#<ClassNotFoundException java.lang.ClassNotFoundException: String>
22:40	justin_smith	,(Class/forName "java.lang.String")
22:40	clojurebot	java.lang.String
23:31	julianleviston	Which is more idiomatic, do you think? (into {} (filter pred m)) or (select-keys m (filter pred (keys m))) ?
23:32	justin_smith	julianleviston: the latter only gets to filter based on the keys...
23:32	justin_smith	but regardless, the former is nicer
23:32	julianleviston	yeah, that’s what I’m trying to do - filter on keys with a predicate...
23:32	julianleviston	justin_smith: why is it nicer, in your opinion?
23:32	justin_smith	less noise
23:33	julianleviston	justin_smith: this is the predicate: #(keyword? (key %))
23:33	julianleviston	well, for the first one
23:33	justin_smith	(comp keyword? key)
23:34	julianleviston	justin_smith: actually I think you’ve answered my question… the second is better because it explains the intent more.
23:34	justin_smith	anyway, the into/filter is a more straightforward combo to my eyes, compared to select keys / filter / keys
23:34	justin_smith	OK
23:34	julianleviston	what I really want is a function select-keys-filter, so maybe I’ll go write that.
23:34	julianleviston	or something with a less ugly name
23:35	julianleviston	justin_smith: I guess that’s probably because the into/filter is more lazy.
23:35	julianleviston	justin_smith: damn clojure and its messy laziness :)
23:35	julianleviston	justin_smith: so, because it’s more lazy, it’s doing less work… :) right? that’s why you intuitively reach for it?
23:36	justin_smith	into isn't lazy
23:36	julianleviston	justin_smith: and I guess wrapping it in a function will name my intent, so convey the sematics better?
23:36	julianleviston	justin_smith: isn’t reduce lazy?
23:36	justin_smith	no
23:37	julianleviston	justin_smith: but it uses a transducer, doesn’t it?
23:37	julianleviston	justin_smith: I thought transducers were
23:37	julianleviston	justin_smith: I guess that’s only if you compose them, then their effect is lazy… hm...
23:37	justin_smith	nope, they are agnostic to laziness for the most part
23:38	justin_smith	the thing using them gets to decide if it is lazy or not
23:38	julianleviston	justin_smith: but if you compose two or more transducers, then the net effect is laziness of function application, isn’t it?
23:38	justin_smith	so a reduce on a transducer is eager, a sequence on a transducer can be lazy
23:38	justin_smith	absolutely not
23:38	julianleviston	guh.
23:38	julianleviston	that’s a bit sucky
23:38	justin_smith	what does lazy function composition even mean?
23:39	julianleviston	justin_smith: no, lazy application
23:39	justin_smith	OK, sequence on a transducer is lazy
23:39	julianleviston	justin_smith: if you compose two functions, and one of them is early aborting as in the case of filter, then its effect is laziness
23:39	justin_smith	reduce isn't
23:39	justin_smith	the transducer is neither lazy nor not lazy
23:39	julianleviston	justin_smith: yes, I know… but the fact that it can be means it is when it can be.
23:39	justin_smith	aborting early is not the same as laziness
23:39	justin_smith	reduce can return early, and is not lazy
23:40	julianleviston	justin_smith: hm… I guess we have different definitions then
23:40	justin_smith	reduce can have a filtered mapping as it's input, it's still going to be eager
23:40	julianleviston	justin_smith: eager meaning it gets all of its arguments before starting?
23:40	julianleviston	justin_smith: right?
23:40	justin_smith	early return isn't lazy, because it is never going to do the hypothetical work that followed - no work is delayed
23:41	julianleviston	justin_smith: yep. cool.
23:41	justin_smith	eager meaning it fully calculates its result when called
23:41	julianleviston	yep tho if the work IS INSIDE the transducer, not outside it, it is lazy… as in… lazy application… not lazy evaluation.
23:41	julianleviston	justin_smith: know what I mean?
23:41	justin_smith	absoluttely not, no, that makes no sense to me
23:41	justin_smith	the transducer is neither lazy nor not-lazy
23:42	justin_smith	it's a transduce
23:42	justin_smith	something lazy or eager can use it
23:42	julianleviston	justin_smith: lazy function application means you don’t apply the function across the whole thing if you don’t have to…
23:42	julianleviston	justin_smith: lazy usually just means the arguments are evaluated before the function begins.
23:42	justin_smith	are you talking about eagerly consuming args? that's not the same as laziness.
23:42	justin_smith	or lack thereof
23:42	julianleviston	justin_smith: hehe :) as I said, we have different definitions of lazy application here.
23:42	justin_smith	(first x) does not fully realize its input. It also is in no way lazy.
23:43	julianleviston	justin_smith: and yes… call it eager consumption, if you like.
23:43	justin_smith	julianleviston: your definition of lazy is not used anywhere in clojure
23:43	ddellacosta	julianleviston: it seems like you are redefining terms idiosyncratically, which does no one any good
23:43	julianleviston	no not at all.
23:43	julianleviston	I explicitly said lazy function application, not lazy evaluation.
23:43	justin_smith	there is no such thing as "lazy function application" in clojure
23:43	ddellacosta	what is the difference between application and evaluation?
23:44	julianleviston	ddellacosta: (apply + [1 2 3]) versus (+ 1 2 3)
23:44	justin_smith	what he means by his invented term "lazy function application" is that the args are not greedily consumed
23:44	ddellacosta	and, if it exists, please point us to some literature where this terminology is used
23:45	julianleviston	ddellacosta: it’s the difference between eval and apply, isn’t it?
23:45	ddellacosta	julianleviston: those two are exactly the same in terms of how they are evaluated. There's nothing "lazy" going on here
23:45	julianleviston	justin_smith: yeah! :)
23:45	ddellacosta	so we are talking about code vs. data? Okay, well, I've never heard lazy used in this context
23:45	julianleviston	ddellacosta: ddellacosta in that case, sure, but if you quote it, then they can be different… right? :)
23:46	julianleviston	ddellacosta: but of course you and justin are completely correct…
23:47	julianleviston	ddellacosta: in clojure, this makes no difference.
23:47	julianleviston	it’s important if you want to do less work, though...
23:47	justin_smith	I don't think the usage of the term lazy is helpful here really. "lazy evaluation" is a thing that exists - see Haskell. And Clojure uses lazy sequences.
23:47	julianleviston	justin_smith: ok I won’t use it then.
23:47	ddellacosta	julianleviston: the main thing is that using an idiosyncratic definition for something--even if you can make yourself understood, eventually--can make it hard to express your point to others
23:47	tomjack	isn't it "call by name"?
23:47	julianleviston	ddellacosta: sure.
23:47	ddellacosta	tomjack: is what "call by name?"
23:48	justin_smith	julianleviston: maybe what you are pointing out is just a side effect of the fact that the last arg to apply can be lazy. And sure, if the function isn't eager to consume that arg, it can be lazy on its args in that sense (though + is going to consume all its args when invoked)
23:48	julianleviston	So… back to the actual discussion, though…
23:48	tomjack	"call by name" is, I think, a maybe less idiosyncratic way to say "lazy function application"
23:49	tomjack	as opposed to clojure's "call by value"
23:49	justin_smith	tomjack: ahh, the way Haskell compiles / evaluates with term rewriting, I can see that
23:49	justin_smith	yeah, Clojure does not share those semantics at all
23:50	julianleviston	justin_smith: because it’s not super lazy… just sometimes lazy… when you specify.
23:50	justin_smith	I mean you can fake it by using delay all over the place but it will be ugly as fuck
23:50	justin_smith	julianleviston: it has lazy sequences
23:50	justin_smith	that's the beginning and end of laziness in clojure
23:50	julianleviston	what I was interested in, is minimizing the amount of work to do, generally… I mean, composing map with some, why map the entire list if we’re only going to use half of it later?
23:50	justin_smith	no lazy evaluation
23:50	julianleviston	justin_smith: yep.
23:51	tomjack	huh, some with map is just Clojure's normal laziness, no?
23:51	julianleviston	so if I make a transducer of partial map with partial some, it should be lazy… but is it? does it work like a unix pipe, or does it just work like ruby? (Doing the whole map first)
23:52	justin_smith	you could say that reduce / reduced meet some other goal of not fully evaluating inputs that laziness does, but then you should consider that every programming language has some version of this (usually the return or continue statements)
23:52	julianleviston	which brings me back to… which is better for early aborting / saving calculations on large lists… (into {} (filter pred m)) or (select-keys m (filter pred (keys m))) ? I guess it makes no difference because neither are
23:52	julianleviston	(sorry sub collections in there where I said lists…)
23:53	justin_smith	julianleviston: the transducer with composition ensures that all the steps are done together for one input. Whether this is eager or lazy is decided by the thing consuming the transducer in most cases.
23:53	julianleviston	justin_smith: that was exactly what I thought… brilliant :)
23:53	julianleviston	justin_smith: but of course, into and silect-keys … both of them aren’t composable in that way, so it makes no difference, correct?
23:54	julianleviston	select*
23:54	justin_smith	sure, and both are fully eager
23:54	julianleviston	I guess select-keys is probably more “efficient”, but it’s only a guess.
23:55	justin_smith	it's easy to test that with criterium
23:55	julianleviston	true!
23:55	julianleviston	will do
23:55	justin_smith	probably looks different with different input sizes
23:55	julianleviston	,(time (let [m {:a "hey" :b "yes" "string-key" "should not include"} pred #(keyword? (key %))] (into {} (filter pred m))))
23:55	julianleviston	, (time (let [m {:a "hey" :b "yes" "string-key" "should not include"} pred #(keyword? %)] (select-keys m (filter pred (keys m)))))
23:55	clojurebot	"Elapsed time: 7.390301 msecs"\n{:b "yes", :a "hey"}
23:55	clojurebot	"Elapsed time: 0.19605 msecs"\n{:a "hey", :b "yes"}
23:55	julianleviston	hm...
23:55	julianleviston	interesting
23:56	julianleviston	justin_smith: yeah, should test with a variety of coll sizes.
23:57	julianleviston	(inc justin_smith)
23:57	lazybot	⇒ 191
23:57	julianleviston	(inc ddellacosta)
23:57	lazybot	⇒ 8
23:57	julianleviston	(inc tomjack)
23:57	lazybot	⇒ 5
23:58	ddellacosta	hmm, I'm kind of surprised those two would differ at all efficiency-wise
23:58	ddellacosta	although actually the second one may have benefitted from caching from the first run
23:58	justin_smith	ddellacosta: the cost of consing up (count m)-n keys vs the cost of removing n keys
23:59	julianleviston	yep.
23:59	julianleviston	makes sense to me…
23:59	julianleviston	because of how into works
23:59	julianleviston	(source into)
23:59	julianleviston	,(source into)
23:59	clojurebot	Source not found\n
23:59	ddellacosta	I guess into is O(n)
23:59	ddellacosta	yeah, into is a reduce
23:59	julianleviston	(reduce conj to from)
23:59	ddellacosta	select-keys is O(n log n)?