#clojure – 2013-03-07

2013-03-07

00:15	devn	Raynes: you got it babe.
00:25	devn	yogthos: howdy
01:18	michaelr5251	I love Thursdays :)
01:20	jeremyheiler	Why is that?
01:21	michaelr5251	Because it's the last work day of the week (here in Israel)
01:21	jeremyheiler	ahihi, that would make Thursday's better.
01:21	jeremyheiler	Ah**
01:28	kencausey	michaelr5251: Do you start again on Sunday or Monday?
01:29	michaelr5251	Sunday
01:29	kencausey	OK, nice to learn new things about distant societies. Thanks!
01:30	michaelr5251	haha
04:08	ciphergoth	It seems weird that if I want a task to happen in a separate thread, I can just give it to an agent, but if the agent wants to try again in one second, I'm going to have to start worrying about Java thread pools. Am I looking at this wrongly?
04:09	mpenet	agents are about shared acces to some state, if doesn't really make sense to use it just to run a task in a separate thread, futures could be better for that
04:11	ciphergoth	agents are appealing because I can send a message to an agent saying "here, add this to the list of things you ask about when you poll"
04:11	mpenet	but anyway, they are backed by a cachedthreadpool so in theory you shouldn't have to worry about that
04:12	ciphergoth	OK
04:12	mpenet	and if you (really) need to take control of the underlying pool you can do it with send-via, if you are running 1.5
04:14	ciphergoth	I don't think I do need or want to take control of the underlying pool - that's what I was hoping to avoid!
04:14	ciphergoth	You say "Supports :at-fixed-rate :with-fixed-delay :once, matching the corresponding Java methods." - I can't find what corresponds to :once, though I can guess what it means
04:14	ciphergoth	it sounds like I can just use your library, and schedule the next poll with (schedule :once :with-fixed-delay 1000 #(send ...))
04:16	mpenet	this matches http://docs.oracle.com/javase/6/docs/api/java/util/concurrent/ScheduledExecutorService.html
04:16	mpenet	and you cannot combine :once :with-fixed-delay
04:17	ciphergoth	"once" doesn't appear on that page
04:17	ciphergoth	OK
04:18	ciphergoth	does "once" take a time to wait before executing?
04:19	mpenet	yes, you can pass :initial-delay, there's an example in the readme
04:19	ciphergoth	ah!
04:20	ciphergoth	am looking at the source now, I see it
04:20	ciphergoth	thank you!
04:20	mpenet	np
04:24	mpenet	technomancy: since clojurescript-mode is deprecated, would it make sense to add cljs extension to auto-mode-alist on clojure-mode?
04:41	Foxboron	Basic question. I got a vec, i want a function to be used on all the items in the vec. I have tried for and map, but still dosnt work.
04:45	mpenet	,(map inc [1 2 3])
04:45	clojurebot	(2 3 4)
04:45	mpenet	,(mapv inc [1 2 3])
04:45	clojurebot	[2 3 4]
04:46	mpenet	Foxboron: maybe you are being tricked by lazyness
04:48	Foxboron	hmm
04:49	Foxboron	mpenet: well basically, i got this IRC bot i want to join several chans. So i got a vec of chans.
04:49	Foxboron	It dosnt even seem to execute the function itself.
04:49	mpenet	you are using map for side effect in other words
04:50	mpenet	either you wrap it with doall, or better use doseq
04:50	Foxboron	ahh doseq.
04:50	Foxboron	awsome, thanks :)
04:52	Foxboron	mpenet: awsome, it works :D
04:58	mpfundstein	whats the newest clojure.contrib version?
04:59	vijaykiran	mpfundstein: there's no clojure.contrib anymore - http://dev.clojure.org/display/design/Where+Did+Clojure.Contrib+Go
05:00	mpfundstein	ah ok
05:01	mpfundstein	so command-line-arguments is now included in clojure?
05:01	mpenet	it's in tools.cli now
05:26	corecode	hi
05:26	corecode	i'm working through the 4clojure excercises
05:26	corecode	and i wonder how to implement an efficient fib sequence
05:27	corecode	that whole recursive call thing is compact but also has a terrible complexity
05:28	corecode	ideally i'd like to use lazy-cons, but i don't know exactly how to
05:31	leku	corecode: good questiosn I think, maybne just bad timing
05:31	leku	it is 4:32 AM here in the US of A
05:32	corecode	no european cljers?
05:32	noidi	corecode, do you want the answer or just a hint? :)
05:32	corecode	so my hunch is that i have to carry along the 2 last fib numbers
05:33	corecode	so that i can grow the sequence
05:33	noidi	yes
05:33	corecode	aha
05:33	corecode	see i watched an outdated talk
05:33	corecode	where rest still returned nil, and lazy-cons existed
05:33	noidi	and the sequence is infinite, so it has to be lazy. hence, wrap it in (lazy-seq ...)
05:33	noidi	and prepend to it using cons
05:52	corecode	hm
05:52	corecode	(take 4 (fn fib [] (cons 1 (cons 1 (lazy-seq (map + (fib) (rest (fib))))))))
05:52	corecode	this doesn't work
05:53	Foxboron	corecode: loop & recur?
05:54	corecode	i'll try that
05:55	noidi	no, recur is strict
05:55	corecode	noidi: you mean loop is?
05:55	noidi	you can use recur without loop :)
05:55	corecode	yes
05:55	corecode	i saw the definition of filter
05:56	noidi	corecode, write a (defn fibs [a b] (lazy-seq ...)) that returns a lazy sequence of all the fibonacci numbers starting with a and b
05:57	noidi	hmm, it's hard to give hints without giving the full solution :)
06:00	noidi	note that in order to be lazy, you must only prepend one concrete result to a lazy sequence that contains the rest of the items
06:00	corecode	right
06:00	corecode	i get an obscure error message
06:00	noidi	welcome to clojure :P
06:00	corecode	IllegalArgumentException Don't know how to create ISeq from: java.lang.Long clojure.lang.RT.seqFrom (RT.java:505)
06:01	noidi	I'd guess you're trying to cons to a number
06:01	noidi	,(cons 1 2)
06:01	clojurebot	#<IllegalArgumentException java.lang.IllegalArgumentException: Don't know how to create ISeq from: java.lang.Long>
06:02	corecode	aha!
06:02	corecode	forgot my actual call
06:02	corecode	very nice
06:03	corecode	(take 10 ((fn fib ([] (cons 1 (fib 0 1))) ([a b] (cons (+ a b) (lazy-seq (fib b (+ a b))))))))
06:03	corecode	yey
06:04	noidi	great :)
06:05	Foxboron	i always struggle with Fib :c. IRC Bot sockets etc? No problem. Pritning 1 1 2 3 5 etc....nope
06:06	noidi	here's what I came up with initially
06:06	noidi	(defn fibs ([] (fibs 0 1)) ([a b] (lazy-seq (cons a (fibs b (+ a b))))))
06:07	Ember-	sniff... beautiful
06:07	corecode	aha
06:07	Ember-	:)
06:07	corecode	yes
06:07	corecode	better
06:18	corecode	huh? why is
06:19	corecode	,(reduce #'and '(false false))
06:19	clojurebot	true
06:19	corecode	oO
06:23	edoloughlin	Anyone using clojure.data.xml? Should this be possible?
06:23	edoloughlin	reply.eval-modes.nrepl=> (use 'clojure.data.xml)
06:23	edoloughlin	nil
06:23	edoloughlin	user=> (emit-str (element :something {} false))
06:23	edoloughlin	IllegalArgumentException No implementation of method: :gen-event of protocol: #'clojure.data.xml/EventGeneration found for class: java.lang.Boolean clojure.core/-cache-protocol-fn (core_deftype.clj:541)
06:44	noidi	corecode, with #' you're getting hold of the function that implements the macro. the fact that macros are implemented as functions is an implementation detail which you shouldn't rely on
06:45	corecode	that's no good
06:45	corecode	that means i need to know what is a macro and what is a function
06:46	noidi	the macro functions take two arguments before the "real" macro arguments, so the result you're getting is the macroexpansion for `and` called without arguments
06:46	noidi	,(macroexpand-1 '(and))
06:46	clojurebot	true
06:46	noidi	yes, you need to know the difference, but Clojure helps you there
06:46	noidi	,and
06:46	clojurebot	#<CompilerException java.lang.RuntimeException: Can't take value of a macro: #'clojure.core/and, compiling:(NO_SOURCE_PATH:0:0)>
06:47	noidi	you've gone around that check by using #' to get hold of the var holding the macro function
06:47	noidi	but you'd get that error if you tried to call (reduce and ...)
06:48	noidi	the proper way to write that reduce would be (reduce #(and %1 %2) ...)
06:58	tsdh	How do you natives say to (map f coll)? f is mapped through the elements of coll?
07:00	ciphergoth	(zipmap (vals map) (keys map))
07:03	noidi	tsdh, I'm not a native English speaker, but I think "f is mapped over ..." is a valid way to put it
07:04	noidi	google seems to agree :) https://www.google.fi/search?q=functional+programming+"is+mapped+over"
07:04	tsdh	noidi: Ok, thanks.
07:06	tsdh	noidi: Ah, it seems one says "f is mapped over coll", or "coll is mapped through f".
07:12	AWizzArd	Is there a better way to consume a PushbackReader stream of Clojure objects? (take-while identity (repeatedly #(read pbr false false)))
08:01	ciphergoth	I'm pretty sure this line is being executed, but trigger-poll isn't being called: (knit/schedule :once :initial-delay 2 trigger-poll)
08:01	ciphergoth	am I missing some kind of setup that makes this work?
08:13	tomoj	should there be (defmacro as->> [name & forms+expr]) ?
08:14	ciphergoth	Is there a better way to do (apply dissoc map keylist)
08:21	Kowboy	cemerick, does CCW have support for ctrl+click navigation to function definitions?
08:21	cemerick	Kowboy: yup
08:21	cemerick	cmd + click on OS X FWIW
08:21	Kowboy	can you think of a reason it wouldn't be working?
08:22	cemerick	Kowboy: do you have a REPL open for the project in question, with your code loaded therein?
08:22	Kowboy	at the moment, no
08:22	cemerick	Do so, and you'll have code completion, go-to-definition, etc
08:23	Kowboy	interesting
08:23	Kowboy	so, the project I am working on loads some namespaces at runtime
08:24	Kowboy	based on configuration
08:24	Kowboy	so I don't get go-to-def functionality on those
08:24	Kowboy	unless I load them in the repl
08:25	mrb_bk	good morning #clojure
08:26	cemerick	Kowboy: right; introspection only ever works if you have a running environment
08:32	Kowboy	is there documentation on the supported features of CCW's paredit mode?
08:33	dan_b	argh classpath. or jni search path, if that's a thing
08:37	clgv	does someone know how to modify the theme of rainbow-delimiters in emacs?
09:21	devn	clgv: (omg (this (looks (like (a (clown car))))))
09:22	clgv	devn: lol. wrong order of the sentence with respect to execution order ;)
09:22	clgv	devn: I hardly see the color distinction with the default fonts...
09:27	Icarot	Guys, I am a terrible programmer.
09:28	Kowboy	can we blame it on Perl?
09:29	Icarot	And for some reason, I cannot for the life of me even formalize in psuedocode how to track the frequency of hours, given some data.
09:29	Icarot	e.g., (1, 12, 30, 13, 14) -> Array[2]
09:30	Icarot	I feel like I'm trying to implement a kth largest element selection algorithm.
09:30	Icarot	except, somewhere along the line, I forgot that I'm an idiot.
09:37	ciphergoth	is there something like ring.mock.request for multipart params?
09:42	grc	macro and meta data problem: I wish to use a macro to define a function with meta-data which is passed as an argument to the macro.
09:42	grc	(defmacro foo [a] `defn ^#{:bar ~a} baz [] 42)
09:43	grc	But this is rejected with (defmacro foo [a] `defn ^#{:bar ~a} baz [] 42)
09:43	grc	or rather java.lang.IllegalArgumentException: Metadata must be Symbol,Keyword,String or Map
09:43	grc	Any suggestions on how to get tehre?
10:07	llasram	grc: Well, you have several problems there
10:08	grc	somehow I'm not surprised! Up for education though
10:08	grc	llasram: ^
10:08	llasram	First: ##(quote '(`defn baz [] 42))
10:08	lazybot	⇒ (quote ((quote clojure.core/defn) baz [] 42))
10:09	llasram	The body of your macro consists of the single syntax-quoted form `defn followed by a bunch of un-quoted things
10:09	llasram	First: ##(`defn baz [] 42)
10:09	lazybot	java.lang.RuntimeException: Unable to resolve symbol: baz in this context
10:10	llasram	Er, didn't mean to re-say "First", but you get the picture
10:10	llasram	Second, the ^{} reader metadata notation is just that -- reader metadata. It puts metadata on the forms being read
10:10	llasram	&(meta (^:example 'x))
10:10	lazybot	clojure.lang.ArityException: Wrong number of args (0) passed to: Symbol
10:11	llasram	&(meta ^:example 'x)
10:11	lazybot	⇒ nil
10:11	llasram	&(macroexpand `(meta (^:example 'x)))
10:11	lazybot	⇒ (clojure.core/meta ((quote clojure.core/x)))
10:11	llasram	&(macroexpand `(meta ^:example 'x))
10:11	lazybot	⇒ (clojure.core/meta (quote clojure.core/x))
10:12	llasram	I keep trying to use paredit in the ERC buffer... apparently need more coffee :-)
10:12	grc	First one was a poor truncation of my actual problem: I'm passing in baz to the macro and teh body reads (defn ~baz ....)
10:13	llasram	Ok
10:14	clgv	grc: if you want help with a macro always show the intended macro call syntax and the expansion you want to create...
10:14	llasram	So skipping along -- because the reader metadata syntax is in fact reader syntax, it applies immediately to forms as they are read
10:14	grc	OK I think I've grokked the reader aspect. For now. So how do I apply meta data to the function I'm defining in the body of teh macro? Is taht through use of (meta ...)
10:14	grc	sorry cross-typing
10:15	llasram	np
10:15	clgv	grc: use `with-meta` on the symbol
10:15	llasram	You need to porgrammatically generate the metadata with ^^ clgv with-meta, or vary-meta
10:17	llasram	&(let [a 'foo, b `~(vary-meta a assoc :example true)] [b (meta b)])
10:17	lazybot	⇒ [foo {:example true}]
10:17	grc	llasram, clgv: whenever I play with macros I seem to get lost in a twisty maze of indirection. I'll go and hack some code, but first and more importantly, think this through properly. Thanks fo ryour help
10:18	llasram	good luck!
10:20	solussd	what's a good way to enforce a protocol's contract when implemented? e.g. if I define a protocol with a function that must return a string, how can I enforce that someone implementing the protocol uses a function that returns a string?
10:21	solussd	in other words, how can I put pre/post conditions on the protocol function declarations?
10:21	llasram	solussd: Does it work to just put the pre/post condition metadata on the protocol function declaration? I know it works with other standard var metadata like :private
10:21	solussd	it does not. :(
10:22	solussd	it is ignored
10:22	llasram	solussd: Aww. Well, I guess create a private protocol and expose public wrapper functions with the conditions?
10:25	solussd	you mean: the protocol could declare a private fucntion, e.g. -protofunc that calls a public function, protofunc which the user of the protocol implements?
10:25	solussd	that was suggested before, I just forgot the details. thanks
10:34	Anderkent	Anyone know why midje might fail to intercept a call to a public function? i.e. (fact <testcode> (provided (a/func anything) => ...result)) , and a/func is called from the testcode.
10:34	Anderkent	It uses the real implementation in and complains that the prerequisite function is never called
10:39	clgv	Anderkent: you will have to post more context.
10:39	Anderkent	figured it out - apparently provided only applies to the latest arrow, not the entire fact
10:39	Anderkent	i.e. (fact (foobar 1) => 1 (foobar 2) => 2 (provided (foobar [x] 2))) can succeed
10:40	Anderkent	rather unintuitive, but well
10:40	danneu	in an OOP language, if you create an array of Tweet objects (with Tweet#text and Tweet#username), is the surrogate for that in clojure a list of {:username _, :text _} hashmaps?
10:42	clgv	danneu: yes
10:42	dan_b	that would certainly be one way to model it
10:42	dan_b	depends what questions you want to ask about that data, i guess
10:43	clgv	danneu: it is the most general way. in special cases you would need defrecords or deftypes if you really need those
10:47	danneu	clgv: thanks. just read about those on the clojure website. i like it
10:49	S11001001	danneu: careful; defrecord/deftype are great ways to overdesign
10:49	clgv	danneu: just start with the maps^^
10:51	danneu	cool. i've been rewriting Ruby to Clojure and have been using hashmaps.
10:52	kittylyst	Am still getting my sea-legs back after an absence. I wrote this to exclude any user with a freeware address (freemail domain held in list) from a list of users:
10:52	kittylyst	(mapcat (fn [domain] (filter #(re-matches (re-pattern (str "." domain ".")) (:email %)) users)) freemail)
10:52	kittylyst	It's obviously inefficient, not that it matters for the list sizes
10:52	kittylyst	Suggestions for a more idiomatic / cleaner solution?
10:53	danneu	My biggest learning obstacle is how to organize my Clojure code that was once organized into succinct Ruby classes.
10:54	kittylyst	Whoops, actually that code returns all the freemail users. C&P wrong code - but basic question stands
10:56	Foxboron	danneu: i was told this. 1 file for one purpose, and namespaces should give you the general idea.
10:56	borkdude	would anyone know why (ref:someid) doesn't work in some clojure code block in org-mode when exported to html?
10:57	borkdude	it does when I put it on its own commented line: ;;(ref:someid)
11:07	danneu	Wow, LightTable is amazing
11:08	Ember-	not ready, but promising, yes
11:09	danneu	Better than my Vim workflow for Clojure
11:09	danneu	At least*
11:09	Anderkent	you don't have a very good vim workflow for clojure then, I guess? :P
11:10	danneu	Anderkent: right. it's hard to arrive at a workflow when im still new to clojure though
11:10	Foxboron	I am using Emacs....but really not THAT happy. Anyoen tried Emacs and VIM with Clojure?
11:11	danneu	and?
11:11	kittylyst	danneu: I am using Emacs on a Mac & am very happy
11:11	Anderkent	fair enough. I find vim-foreplay and a backgrounded repl work nice (though because of YouCompleteMe if I don't have a repl open opening a file takes a while as it times out while connecting - need to get that fixed)
11:11	danneu	I didn't mean to suggest that anyone was unhappy with their setup! I just meant to express some love for LightTable
11:12	pimeys	I found it pretty horrible at this point
11:12	pimeys	but 15 years of history with vim and now using emacs, I kind of find every other editor pretty horrible
11:13	danneu	pimeys: yeah i guess it's just the simple point of clojure (and jvm build step) being new enough to me to where using a ide at the beginning is more convenient than the convience of editing code with vim
11:13	pimeys	what's the difference between an ide and emacs/vim :)
11:13	pimeys	less menus?
11:13	pimeys	no, emacs has menus
11:13	pimeys	ok, setting them up requires some patience
11:14	arrdem	plugin systems that don't suck?
11:14	danneu	hey now, vim with vundle is nice!
11:14	pimeys	very
11:14	mpfundstein	Foxboron: i do all coding in vim
11:14	pimeys	and emacs with elpa
11:14	mpfundstein	Foxboron: fastest environment for editing code
11:15	Foxboron	mpfundstein: well, i was more after someone who have used both heavily and can elaborate on what they think
11:15	pimeys	vim command mode must be the best way to edit anything
11:15	Foxboron	mpfundstein: "fastest enviorment" is a relativ term for the person
11:15	danneu	by ide i guess i mean software that tends to handle build steps for you and integrate with them. like showing you eval'd output next to the code.
11:15	clgv	danneu: you can try counterclockwise as well ;)
11:15	Anderkent	clgv: not until slurp and barf are in :P
11:15	pimeys	danneu: so, emacs is an ide :)
11:15	clgv	Anderkent: your choice ;)
11:16	clgv	emacs is an operating system :P
11:16	Foxboron	hahaha
11:16	Foxboron	with a bad text editor
11:16	pimeys	and a potato
11:16	pimeys	Foxboron: with evil mode, it's pretty good
11:16	pimeys	and all those evil plugins
11:16	Anderkent	I use vim, actually :P having to toggle paredit to fix every single mistake in counterclockwise is just too much pain for me
11:16	nDuff	danneu: Personally, LightTable is great for exploration, but I find myself using emacs+nrepl for interactive evaluation when doing real work.
11:16	Foxboron	pimeys: i know, i use evil mode. Just gotta learn the vim keybinds better
11:16	nDuff	Anderkent: that's only the case because CCW's paredit is underpowered.
11:17	pimeys	I cannot use emacs without it
11:17	pimeys	but everything else in emacs is better than in vim
11:17	nDuff	Anderkent: ...full emacs paredit you don't _need_ to disable to fix mistakes.
11:17	pimeys	vim has a better editor
11:17	clgv	Anderkent: "toggle paredit to fix ..." care to explain what you mean exactly?
11:17	danneu	nDuff: cool, that's what i was trying to say
11:17	arkx	Again this discussion… :)
11:17	Anderkent	nDuff: yes, that's why I said I need slurp/barf
11:17	nDuff	Anderkent: nod.
11:18	Anderkent	clgv: say I want to do ((function arg1 arg2) arg3) but type ((function arg1) arg2 arg3)
11:18	Anderkent	to fix it in counterclockwise I have to disable paredit and move the paren by hand
11:18	Anderkent	in vim i just go to the paren and press ,>
11:19	clgv	Anderkent: laurent mentioned that the underlying lib for paredit got more functionality lately. so the missing parts will be there soon^^
11:21	Anderkent	yeah, I have the issue starred :) Once it's in I might switch to ccw just for the debugging support
11:26	corecode	what's counterclockwise?
11:26	nDuff	corecode: Clojure plug-in for a Java IDE; I don't offhand recall which one.
11:26	corecode	ah
11:27	nDuff	Anderkent: With respect to debugging support, I'm hoping to see ritz merged into emacs-live soon.
11:27	corecode	nm then
11:29	clgv	eclipse ;)
11:36	gfredericks	derefing a private atom: @@#'foo.bar/baz
11:36	pjstadig	gfredericks: you should be ashamed
11:37	nDuff	That's... actually a lot less ugly than how I'm getting into clojure.data.xml's privates.
11:37	Anderkent	also a lot nicer than how I'm changing the set of currently loaded namespace in clojure.core ...
11:37	pjstadig	of course i should talk https://github.com/pjstadig/nio/blob/master/src/nio/core.clj#L48
11:38	Anderkent	https://github.com/lshift/cloverage/blob/master/cloverage/src/cloverage/coverage.clj#L103
11:38	Anderkent	are we bringing out the dirt? :P
11:39	Anderkent	(I know I should be doing it via #' probably, but at the time it was an improvement over (in-ns 'clojure.core) (apply ...) (in-ns orig-ns) :D
11:39	nDuff	...had forgotten about #', which is considerably the saner approach.
11:40	nDuff	(convincing relevant folks to expose the function, of course, being ideal, _but_).
11:40	Anderkent	but indeed
11:52	gfredericks	in this case I am the relevant folk.
11:52	gfredericks	I tend to privatize things even when their publicity makes testing easier
11:52	corecode	is there a way to revert (use)?
11:52	clgv	let's really free those functions in these open source projects by declaring them public ;)
11:53	clgv	there was a call for that for java open source projects ;)
11:53	nDuff	gfredericks: ...the relevant folk for clojure.data.xml, you mean?
11:53	clgv	corecode: only for the mapping part
11:54	nDuff	gfredericks: ...because if so, yes, I'd welcome an opportunity to lobby for making pull-seq public
11:54	clgv	corecode: ns-unmap
11:55	nDuff	(as is the case when trying to handle results from javax.xml.xquery)
11:55	corecode	clgv: what does that mean, for the mapping part?
11:55	corecode	clgv: (use 'clojure.string) overwrote my 'reverse
11:55	corecode	:/
11:55	clgv	corecode: without classloader artistic you can not undo that the namespace was loaded
11:55	corecode	(in the repl)
11:56	clgv	corecode: the lesson here is to use (require '[clojure.string :as str]) and using e.g. (str/join ...)
11:56	corecode	:)
11:57	corecode	yea, i'm still struggling with use, require, import
11:59	llasram	corecode: You can ignore `use` for new >=1.4 code
11:59	corecode	okay
12:00	llasram	(:use [some.namespace :only [foo]]) <-> (:require [some.namespace :refer [foo]])
12:01	papachan	weird
12:01	papachan	i have a Exception in thread "main" java.lang.ExceptionInInitializerError
12:01	clgv	llasram: `use` is not deprecated in the docs though. is the intention to get rid of `use`?
12:01	papachan	when i launch today clojure
12:02	llasram	clgv: My understanding is that it's kind of "unofficially deprecated". Not sure why not officially, since `require` now can do everything `use` does
12:03	papachan	nothing say. it working fine now
12:04	gfredericks	nDuff: not clojure.data.xml, just my own code
12:05	gfredericks	don't futures run in a fixed-size thread pool? How does that interact with IO-bound futures?
12:06	technomancy	IIRC they use the send-off pool
12:06	gfredericks	I create 300 futures with a Thread/sleep in them, and apparently they all are running in parallel
12:06	llasram	gfredericks: Yeah, futures use the Agent/soloExecutor pool, which unbounded
12:07	gfredericks	ah ha
12:07	gfredericks	so if I want a bounded number of jobs running at one time, I need a different mechanism
12:07	llasram	send-via!
12:07	llasram	Well, or just a queue
12:13	jcidaho`	Hi - anyone got any elisp using nrepl for loading a default ns when nrepl loads in a project - I know this question has been asked a few times. I've got some for if the user has the project.clj open, but if any file in the directory tree for that project is open it's proving very tricky
12:14	technomancy	jcidaho`: I think there's an open pull request for that in nrepl.el that hasn't been applied yet
12:15	jcidaho`	Does it work :-) I'll try it
12:15	borkdude	what's the difference between require with no options such as :as and load?
12:16	gfredericks	borkdude: require will only load once
12:17	borkdude	I wondered why this file contains load statements: https://github.com/clojure/clojure/blob/master/src/clj/clojure/pprint.clj
12:17	technomancy	load lets you do terrible things with namespaces
12:18	llasram	Well, I wouldn't say "terrible." It lets you divide a single namespace into multiple files.
12:18	Anderkent	borkdude: because load doesnt enforce the other file to have its own namespace
12:21	technomancy	load is only suitable for development tools to use; you shouldn't use it in actual code
12:21	Anderkent	I guess the drawback is it's hard for a person to find the source for a function by hand
12:21	Anderkent	(a tool obviously can just load the ns and look at the metadata of the function to locate it)
12:21	tgoossens	how can i load a jar file for use in repl?
12:21	llasram	technomancy: Why so?
12:21	Anderkent	tgoossens: after starting the repl or before?
12:22	tgoossens	preferably after ?
12:22	llasram	It seems like otherwise people go through weird contortions to define vars in implementation namespace then expose them in API namespaces
12:22	technomancy	llasram: because you are not a unique snowflake; you can follow the rules for namespaces like everyone else =)
12:22	Anderkent	tgoossens: you can use clojure.core/add-classpath , though it seems it was deprecated
12:22	Anderkent	not sure what the suggested alternative is
12:23	jballanc	,(when-let [foo (:bar {:bar nil})] (println "This makes sense"))
12:23	clojurebot	nil
12:23	llasram	tgoossens, Anderkent: you can use pomegranate to add arbitrary deps via aether dependency resolution
12:23	jballanc	,(when-let [{:keys foo} {:bar nil}] (println "This seems like a bug"))
12:23	clojurebot	#<IllegalArgumentException java.lang.IllegalArgumentException: Don't know how to create ISeq from: clojure.lang.Symbol>
12:23	jballanc	whoops...meant this
12:23	jballanc	,(when-let [{:keys [foo]} {:bar nil}] (println "This seems like a bug"))
12:23	clojurebot	This seems like a bug\n
12:23	jballanc	^^^ any reason why ":keys" destructuring does that?
12:24	llasram	technomancy: I honestly haven't had a big need for it in my code, but having some mechanism for implementation/interface separation seems sensible, and `load` seems to be the closest the stdlib gets
12:24	Anderkent	technomancy: uh any actual examples of how it's bad? I.e. what intuition about namespaces does it break for you?
12:25	technomancy	Anderkent: for starters, it leads to files that don't have ns forms in them
12:25	llasram	jballanc: when-let just checks to ensure that the expression is non-nil, and `{:bar nil}` is definitely non-nil. It can't check that each of your destructured things is non-nil without essentially re-implementing destructuring
12:25	Anderkent	sure, but these files are not exposed, so consumers of the lib don't care?
12:26	technomancy	Anderkent: regularity makes for fewer surprises in tooling
12:26	technomancy	using load is like using resolve; it's a sign that you're getting clever and whatever you're doing will confuse automated tools
12:27	technomancy	llasram: it doesn't really help with implementation/interface separation since all the implementation stuff still lives in the same namespace
12:27	technomancy	so someone browsing via ns-map will still see it
12:28	llasram	technomancy: I was just thinking that... Good point
12:28	jballanc	llasram: ok, yeah...that makes sense
12:28	Anderkent	isn't that ns-map's fault for showing private members by default?
12:30	Anderkent	I mean it seems to me that since any tool can find the file a particular symbol was defined in no matter if it's required or loaded this isn't really that bad
12:30	technomancy	Anderkent: depends on what you want. you can use ns-publics for that case. but my point is that public/private is how you address hiding; putting it in separate files doesn't help.
12:30	hiredman	and hiding is dumb
12:31	hiredman	don't do it
12:31	technomancy	if I were reading through code and wondering what namespaces it required, I would be really annoyed if I couldn't just go to the top of the file to find it
12:31	hiredman	I say this as someone staring at the stuff I need in the guts of javamail, and I have to use reflection to get it
12:35	corecode	clojure makes my head pop
12:37	solussd	erm.. when did clojure.core/protocol? become private?
12:38	solussd	..and why?
12:49	pjstadig	hiredman: "and hiding is dumb" you say that now, but when they are banging down your door...you'll hide
12:55	technomancy	heh
13:01	tgoossens	with paredit ((xx)) -> (xx) . I'm unable to do it so far :p
13:01	technomancy	tgoossens: M-s
13:01	tgoossens	let my try that :)
13:02	ed_g	tgoossens, another way is kill the (xx) and yank it somewhere else, then you can erase the emtpy ()'s
13:02	tgoossens	pfft :p
13:03	solussd	how can I tell if something is a protocol now that I don't have the "protocol?" function?
13:03	borkdude	tgoossens I defined this in a script which I load for every repl I spin up: https://www.refheap.com/paste/12229
13:03	borkdude	tgoossens so I can load in dependencies afterwards, if I need them
13:04	tgoossens	mmyes
13:04	tgoossens	thanks
13:04	llasram	solussd: When do you need to test if something is a protocol? In ClojureScript protocols aren't even reified -- there's nothing to call a `protocol?` function on
13:10	tgoossens	interesting
13:11	tgoossens	(using leiningen resource paths) i import classes from a jar into my mainspace
13:11	tgoossens	for some classes I finds a class , for others classdefnotdound
13:29	fbernier	how could I pass what's inside a vector as arguments to recur ?
13:31	fbernier	since apply recur seems invalid
13:31	llasram	fbernier: Manual unpacking, I'm afraid. Or alter your interface so you're `recur`ing on a vector
13:32	technomancy	recur is weird since it's not technically a new function invocation
13:32	technomancy	it doesn't even re-apply destructuring, which is really surprising to most people
13:36	fbernier	I see
13:36	fbernier	thanks
13:37	fbernier	I was trying to remove the loop from my 4clojure solution since I realized you can recur on functions
13:37	fbernier	but I think It's better to leave it there in this case
13:44	jweiss	is there a way to compose this with comp and/or partial - (fn [x & args] (apply hash-set x args))
13:46	Anderkent	technomancy: how do you mean it doesnt apply destructuring?
13:46	Anderkent	,((fn [[head & rest]] (prn head) (when rest (recur rest))) [1 2 3 4])
13:46	clojurebot	1\n2\n3\n4\n
13:46	Anderkent	that seems to destructure it fine?
13:46	borkdude	jweiss ((partial hash-set 1) 2 3) ?
13:49	technomancy	Anderkent: sorry, I meant rest args
13:49	technomancy	,((fn [head & rest] (prn head) (when rest (recur rest))) 1 2 3 4)
13:49	clojurebot	#<CompilerException java.lang.IllegalArgumentException: Mismatched argument count to recur, expected: 2 args, got: 1, compiling:(NO_SOURCE_PATH:0:0)>
13:49	Anderkent	right, ok
13:50	technomancy	,((fn f [head & rest] (prn head) (when rest (f rest))) 1 2 3 4) ; whereas re-invoking f works fine
13:50	clojurebot	1\n(2 3 4)\n
13:51	technomancy	eh; I guess you'd need to apply there. anyway, it's unexpected
13:52	hiredman	yeah, varargs in fns don't really mesh with destructuring, even though the syntax is the same
13:54	gfredericks	if I don't shutdown a thread pool, but I lose refs to it and it runs out of jobs, will it be GC'd? or is shutdown important?
13:55	pjstadig	gfredericks: YOU'RE BONED!
13:55	gfredericks	O_O
13:55	pjstadig	just kidding, i don't really know
13:55	pjstadig	i'm not a clojure programmer, i just play one on tv
13:55	technomancy	you can't shut down your computer anymore
13:55	gfredericks	oh pjstadig. always yelling at people that they're boned.
13:55	technomancy	those threads will just run to the heat death of the universe, sorry
13:55	hiredman	http://stackoverflow.com/questions/7728102/why-doesnt-this-thread-pool-get-garbage-collected
13:56	gfredericks	hiredman: thanks! Now I am no longer boned.
14:09	ghadishayban	I wish there was a most remote REPL award, because only today, I'd win it
14:09	tgoossens	if (ns :import [pgx.blablah ClassName]) gives NO compile error. But (ClassName. xxxx) throws a classdefnotfound. Then what might be wrong?
14:10	ghadishayban	I'm sitting in north Lebanon (http://goo.gl/maps/mClpg) sipping packets off a wireless mesh network connecting the hilltops
14:10	ghadishayban	at a breezy 15KB/s
14:11	ghadishayban	wish I could nREPL everyone in
14:16	ghadishayban	tgoossens: i think i know what you mean, but that ns form should give you a compile error. can you paste specifics into refheap?
14:16	tgoossens	sure
14:16	tgoossens	interesting. (new to emacs) how do i copy from emacs to another app? :p
14:17	ghadishayban	highlight and then Meta-W should do it (i'm new too)
14:17	technomancy	tgoossens: depends on the OS
14:18	tgoossens	hmm (linux)
14:18	technomancy	the correct answer is that if you do everything in Emacs, you don't ever have to
14:18	tgoossens	tsssk :p
14:18	llasram	heh
14:18	chronno	ha
14:19	tgoossens	M-W does the trick
14:19	ghadishayban	sudo technomancy
14:19	tgoossens	https://www.refheap.com/paste/12234
14:19	ghadishayban	errgh su
14:19	tgoossens	ghadishayban: https://www.refheap.com/paste/12234
14:19	llasram	tgoossens: If you enable cua-mode, you can just use ctrl-{x,c,v}
14:20	tgoossens	llasrm: interesting
14:20	technomancy	cua-mode has composability issues
14:20	llasram	I don't do it myself, but it might be an easier path to having the same bindings in emacs as in your other apps
14:20	llasram	technomancy: I thought they'd ironed most of those out?
14:21	chronno	as technomancy said, if you were trying to copy something to paste it in refheap, you don't have to leave emacs: https://github.com/Raynes/refheap.el/blob/master/refheap.el
14:21	ghadishayban	tgoossens: your threading form is the culprit,
14:21	technomancy	llasram: there are workarounds, but it's not the kind of problem you can just solve
14:21	tgoossens	interesting
14:21	tgoossens	how come?
14:21	ghadishayban	make sure you do (-> (Constructor.) ... blah)
14:21	tgoossens	aha
14:21	tgoossens	of course
14:21	tgoossens	stupid me
14:22	tgoossens	yeah it works now :)
14:23	ghadishayban	the threading form needs something tangible to "carry" through the form
14:24	tgoossens	you are completely right. many thanks
14:24	jweiss	borkdude: ##((partial hash-set) nil 2 3)
14:24	lazybot	clojure.lang.ArityException: Wrong number of args (1) passed to: core$partial
14:25	jweiss	borkdude: i'm trying to create the function before x and args are known
14:25	borkdude	,((partial hash-set 1) 2 3)
14:25	clojurebot	#{1 2 3}
14:25	jweiss	so you are including x in the partial
14:26	borkdude	,(fn [x & args] (apply hash-set x args)) ;; why no good?
14:26	clojurebot	#<sandbox$eval69$fn__70 sandbox$eval69$fn__70@f7d693>
14:26	asteve	ain't no party like a clojure party because a clojure party causes you to determine how many parenthesis!
14:26	jweiss	borkdude: it's fine, just asking if there was another way
14:26	jweiss	the general problem is i want to update a value to add to a hash-set, but the value might start off as nil
14:27	rabbit_airstrike	so I inherited this big clojure project, and just stumbled across a 75 line defn with 17 optional args
14:27	borkdude	jweiss there are dozens of other ways, but this is the most obvious one. but hash-set already accepts the same arguments
14:27	jweiss	so i wanted a function that always returns a hash-set. conj will assume nil is a list
14:27	rabbit_airstrike	I feel ill just looking at it
14:27	borkdude	jweiss this sounds like into?
14:28	borkdude	jweiss or remove the nils?
14:28	jweiss	,(apply into #{} nil #{2 3})
14:28	clojurebot	#<ArityException clojure.lang.ArityException: Wrong number of args (4) passed to: core$into>
14:28	borkdude	,(hash-set nil 1 2 3)
14:28	clojurebot	#{nil 1 2 3}
14:28	jweiss	,(into #{} nil #{2 3})
14:28	clojurebot	#<ArityException clojure.lang.ArityException: Wrong number of args (3) passed to: core$into>
14:28	borkdude	,(doc into)
14:28	clojurebot	"([to from]); Returns a new coll consisting of to-coll with all of the items of from-coll conjoined."
14:29	borkdude	,(into #{} nil)
14:29	clojurebot	#{}
14:29	jweiss	,((comp conj (partial into #{}) nil 1)
14:29	clojurebot	#<RuntimeException java.lang.RuntimeException: EOF while reading>
14:29	technomancy	I wonder why compojure's site handler doesn't use wrap-file-info
14:29	jweiss	,((comp conj (partial into #{})) nil 1)
14:29	clojurebot	#<ArityException clojure.lang.ArityException: Wrong number of args (3) passed to: core$into>
14:29	jweiss	bah
14:33	borkdude	jweiss:
14:33	borkdude	,(reduce #(if (nil? %2) %1 (conj %1 %2)) #{} [nil 1 2 3]) ?
14:33	clojurebot	#{1 2 3}
14:34	jweiss	I really just want conj, except i want the final value to be a hash-set even if the inital list is nil
14:34	jweiss	but yeah that's pretty much what you wrote :)
14:35	gfredericks	(fnil conj #{})
14:35	borkdude	,(apply hash-set (remove nil? [nil 1 2 3]))
14:35	clojurebot	#{1 2 3}
14:36	jweiss	gfredericks: +10 internets :)
14:36	borkdude	gfredericks jweiss ah :)
14:36	borkdude	fnil
14:37	jweiss	,((fnil conj (hash-set)) nil 1)
14:37	clojurebot	#{1}
14:37	jweiss	w00t
14:38	noidi	wow, fnil looks really useful
14:38	borkdude	this week's function: fnil
14:38	owengalenjones	anyone have an idea why the second fact form would fail? Only difference is using the hash lookups: http://d.pr/i/Patj
14:39	noidi	owengalenjones, how does it fail?
14:40	owengalenjones	noidi: http://d.pr/i/IzsC
14:40	jweiss	thanks Raynes - i really should just add useful to my project.clj so i can browse around when i need something
14:40	noidi	a bit OT, but I'd replace the lookups with concrete values
14:41	owengalenjones	so just not use hashes?
14:41	noidi	(call ..url.. :login "valid-user" "valid-key")
14:41	hiredman	I would stop using midje
14:41	owengalenjones	?
14:42	hiredman	my guess is it is doing something ridiculous
14:42	noidi	owengalenjones, btw. in your first example you call (login ..url.. ...), in the other you're doing (login "http" ...)
14:45	owengalenjones	noidi: from prior tests, still happens without :( oh well thanks for your time
14:45	nDuff	Emacs clojure-mode question -- how can one pull up the next token, when potentially separated by larger amounts of whitespace, to start only a space away from the current token?
14:45	technomancy	nDuff: M-SPC
14:46	nDuff	technomancy: shoot; I'll have to adjust my window manager's keybindings to get it to give that up.
14:46	technomancy	nDuff: esc spc?
14:46	nDuff	Ahh; that works.
14:48	noidi	owengalenjones, FWIW, I'd rewrite the test like this https://www.refheap.com/paste/12235
14:48	nDuff	Is there a cheaper way to cancel a transaction than throwing an exception?
14:48	noidi	the only args whose value is important is the :login arg to call
14:48	noidi	-s
15:14	actsasgeek	I have an application that refreshes data from a database. Because the data fetch is initiated by a work request and these all arrive at the same time every day and at once, I have to keep from doing multiple data fetches. What seemed to work is a future wrapped in a delay wrapped in an atom. In local testing this was fine, but now I'm seeing multiple hits on the database. Is there a known solution for this use case? I'm not sure what the problem is
15:14	actsasgeek	unless (-> cache deref deref deref) isn't getting the right locks. Any suggestions?
15:22	nDuff	actsasgeek: That seems like serious overkill.
15:23	nDuff	...but anyhow, that's beside the point of the behavior at hand.
15:23	amalloy	nDuff: i actually use a data structure that looks like (atom {:key (delay (future ...))}). it's more useful than you think
15:24	Bronsa	but then you have to @@(:key @map) :(
15:24	actsasgeek	it may well be. The data has to be re-fetched every day so that suggests an atom. The data fetch is initiated by the first thread that gets there so that suggests a future and I don't want it to execute until it is demanded so that suggests a delay.
15:24	amalloy	if you want to store a fugure in an atom, the only way to get it there is with a swap!, and since that can retry, you can't actually create the future inside of the swap!
15:25	amalloy	so, wrap it in a delay, let the first guy "win", and then deref it when you're done swapping
15:25	nDuff	amalloy: ...ahh; that makes sense.
15:27	pjstadig	actsasgeek: if you want something to not happen until you demand it you use a delay, but i'm not understanding where the future comes in
15:29	actsasgeek	sorry. this is basically what I have which may make more sense than me describing it: http://pastebin.com/qJy7MqxC
15:30	nDuff	actsasgeek: would you mind putting that somewhere without the animated flash-based advertising?
15:30	actsasgeek	no problem.
15:30	nDuff	(we're partial to refheap, here, being as it's written in Clojure)
15:31	actsasgeek	here you go: https://www.refheap.com/paste/12239
15:32	Raynes	nDuff: o/
15:32	Raynes	My buddy, my pal.
15:32	actsasgeek	oddly enough this works…you only see "reading the actual database" once and you always get the same value until you update -database.
15:32	amalloy	actsasgeek: this test code doesn't look threadsafe at all. what if all 10 threads you start block for a second or so before the scheduler gets around to them? then the reset-calc and update-database functions get called before any calls to the original cache happen
15:32	actsasgeek	…but not in real life.
15:33	amalloy	or if one of them runs, you hit the database, you reset, and then the rest run? they hit the database a second time
15:33	nDuff	actsasgeek: If you want the test to be a more realistic one, make the read-database call block for a while.
15:34	nDuff	(and, err, I'm not sure what the future is giving you here that you don't already get from the delay).
15:35	actsasgeek	do delays block other threads?
15:35	amalloy	"block other threads" doesn't make sense as a question
15:35	nDuff	Ahh, gotcha.
15:36	nDuff	...delay doesn't document its semantics there.
15:37	actsasgeek	as I understand it. a dereferenced future causes the calculation to be performed in another thread, prevents other threads from doing the same (blocks them), and returns the value of the calculation to everyone.
15:37	actsasgeek	so no subsequent thread causes the function in the future to be executed.
15:38	actsasgeek	a delay only prevents any enclosed value from being evaluated but the evaluation, when dereferenced, is on the dereferencing thread. (could be wrong here).
15:39	pjstadig	delay also caches the result and returns the cached result on future derefs
15:39	nDuff	I'm not sure those nest the way you want them to, though. If dereffing the delay twice at the same time creates two different futures (before the first one has finished and been cached), you've got your race.
15:39	actsasgeek	yes, that's what I'm afraid of.
15:39	amalloy	nDuff: it doesn't, though. dereferencing a delay blocks just as much as dereferencing a future
15:40	nDuff	amalloy: Ahh. If _that's_ the case, there's no need for the future at all.
15:40	amalloy	it's what they're for: the &body of a delay will never be executed more than once
15:41	amalloy	"invoke the body only the first time it is forced"
15:41	amalloy	but really, a lot of clojure's promises aren't painted in bright-red letters
15:41	actsasgeek	except the future executes in a separate thread…maybe there's no reason for the delay? just the future?
15:42	actsasgeek	ideally there are multiple threads requesting work and multiple threads getting data together…but I need only one actual request for each data element.
15:42	nDuff	actsasgeek: ...well, the future starts immediately on creation.
15:42	nDuff	actsasgeek: it's up to you whether you want to precache the value or wait for someone to want to retrieve it.
15:42	actsasgeek	nDuff: which is why I wrapped it in a delay :(
15:43	actsasgeek	but apparently those don't compose well.
15:43	nDuff	Err.
15:43	sritchie	cemerick: what was that ring handler you had that forced https?
15:43	sritchie	didnt' bookmark that library
15:43	nDuff	I don't think "delays don't compose well" is established takeaway here.
15:43	Bronsa	o
15:43	cemerick	sritchie: it's a separate middleware in Friend
15:43	cemerick	sritchie: requires-scheme*
15:43	sritchie	okay, but that's where I can find it
15:44	sritchie	yeah, cool
15:44	pjstadig	actsasgeek: why is it important that it happen in a separate thread? the first thread to deref a delay will execute it, is that bad?
15:45	pjstadig	if you want it to happen on a separate thread, then you want a delay wrapped future, but if it can happen on the first deref'ing thread, then a delay should suffice
15:45	nDuff	actsasgeek: ...what I'm getting from amalloy's clarification is that you really don't need the future here, and only need the delay.
15:45	actsasgeek	pjstadig: to do the work there are multiple large (several Gb) Hive queries…I don't want to do them serially.
15:45	pjstadig	they would happen serially on the future's thread?
15:45	actsasgeek	each request is a separate one of these caches.
15:46	actsasgeek	nDuff: I thought I tried that first…but I could be concurrency punchdrunk.
15:46	sabraham	hey, multithreading question for the room: i'm getting a weird issue with an agent hanging: in the dispatch action to the agent, there's a call to pmap of a function-- when i use pmap the agent hangs, when i map instead, the dispatch action completes
15:46	sabraham	anyone have any insight as to why that may be happening?
15:47	ravster	hey all
15:47	actsasgeek	nDuff: oh, I probably didn't because again, there are several of these caches being managed, each with a 20 minute Hive query. I'd rather do them in parallel.
15:48	corecode	is there a FAQ on "none of my friends understand my exitement with clojure"?
15:49	actsasgeek	the box I'm running on has 76Gb of memory and 24 cores.
15:49	nDuff	actsasgeek: ...but you're acting to prevent them from running in parallel by doing the triple-deref, which blocks until there's a result to continue.
15:50	nDuff	actsasgeek: If you wanted to kick them off by dereffing all the delays but not the futures in an initial stage, _that_ I'd understand.
15:50	llasram	sabraham: I can't think of a reason off the top of my head. Can you reproduce with a minimal example?
15:53	sabraham	llasram, i'll try and concoct something and report back
15:53	actsasgeek	nDuff: yeah, I think you're right…my mental image of how the data request threads and work request threads interacted wasn't quite correct.
15:54	sabraham	one possiblity is that pmap uses the same threadpool as the agent's, so maybe pmap is requesting the agent thread?
15:54	amalloy	sabraham: futures use an unbounded thread pool
15:54	sabraham	one thing i think i have ruled out is that the agent is in a failed state, as a i have an error handler set on it, and it never reports
15:55	actsasgeek	amalloy: I now understand your confusion…those stray functions before the (dotimes…) were not called in the REPL that way…it's just where I pasted them.
15:56	jtoy	can maps hold millions of key/value pairs ?
15:56	actsasgeek	nDuff: how can I make that read-database function block in Clojure?
15:57	amalloy	jtoy: try it and see
15:58	sabraham	amalloy: ah, i see. i wonder why i was mistaken. out of ideas then
15:58	actsasgeek	jtoy: yes. I have one that has 25Gb of data: long => [long]
15:59	jtoy	actsasgeek: gret to hear, im going to use a clojure hash-map inside of hadoop
15:59	actsasgeek	maybe not quite that much…25 million records, though.
15:59	actsasgeek	I'm holding the results of a Hive query in one.
16:00	actsasgeek	actually, I'm holding the results of 5 Hive queries in 5 of them.
16:00	jtoy	actsasgeek: mine should only be 1-2 million
16:05	actsasgeek	nDuff: LOL…just make it sleep. Darn but I've been at this too long today.
16:12	puchacz	hi, I come from Common Lisp. I would like to read something about streams, iterators and generators
16:12	puchacz	to steal some ideas
16:13	hiredman	clojure has none of those things
16:13	technomancy	yeah, not having any of those is a pretty good idea worth stealing
16:14	technomancy	the main thing CL could learn from Clojure is that sometimes you have to remove things to improve the language
16:14	puchacz	really? streams can be non-destructive, purely functinal
16:14	technomancy	but the CL mantra is that you can always improve the language by adding new things; macros will save us, etc.
16:15	actsasgeek	nDuff, amalloy thanks for you help.
16:15	puchacz	right, did I start religious war? I did not intend to
16:15	Raynes	No.
16:15	Raynes	You provoked the two hardest to please people in the channel is all.
16:15	Raynes	Carry on.
16:15	pjstadig	haha
16:15	amalloy	technomancy has been promoted to "religious war"? this is excellent
16:16	pppaul	puchacz there is a library that adds channels to clojure… i think it may be similar to streams
16:16	ToBeReplaced	is there a lazy-shuffle implementation lying around?
16:16	duck1123	Lamina is probably what you want
16:16	puchacz	so seriously, what would you recommend to read on clojure way dealing with restartable, and long data sources?
16:16	brehaut	puchacz: Oleg has got your back http://okmij.org/ftp/Streams.html http://okmij.org/ftp/continuations/
16:16	Raynes	amalloy: %!
16:16	Raynes	amalloy: Someone just asked for lazy shuffle. Your time has come.
16:16	trptcolin	brehaut: beat me to it. that is something to read, indeed
16:16	amalloy	omgomgomg
16:17	brehaut	trptcolin: i recognise most of the words as words anyway
16:17	puchacz	ok, thanks, will check Oleg. just heard about him on CL channel
16:17	brehaut	puchacz: thats because Oleg has a brain the size of a small planet and has covered all this stuff
16:17	amalloy	except my current implementation is a bit stupid. take-shuffled requires a numeric arg, instead of just giving you all of them and letting you use take
16:18	amalloy	i must have a real lazy-shuffle around somewhere
16:18	technomancy	I dunno; a lot of people come asking how to learn from clojure's approach to concurrency, when usually the answer is just that referential transparency makes it a non-issue.
16:19	puchacz	coolio, starting to read. thanks
16:19	technomancy	"When he heard this, he left very sad, because he was a man of great wealth."
16:19	amalloy	try https://www.refheap.com/paste/c8275b404d8ec64446008ede5
16:19	gfredericks	yep, religious war
16:19	brehaut	technomancy: you are biblical motherfucker
16:20	amalloy	(ToBeReplaced)
16:20	ToBeReplaced	amalloy: thanks looking
16:20	technomancy	brehaut: sell all your mutable data structures and give to the poor, and you will have concurrency.
16:21	brehaut	(inc technomancy)
16:21	lazybot	⇒ 47
16:21	hiredman	~#68
16:21	clojurebot	68. If we believe in data structures, we must believe in independent (hence simultaneous) processing. For why else would we collect items within a structure? Why do we tolerate languages that give us the one without the other? -- Alan J. Perlis
16:22	technomancy	brehaut: it's easier for a camel to go through the eye of a needle than for an imperative program to run concurrently without bugs.
16:22	technomancy	ok, I'm done
16:22	llasram	Truly, it is easier for an experienced programmer to pass through the pages of the Camel book than to enter the kingdom of the concurrent
16:22	technomancy	nice!
16:23	gfredericks	any #clojure conversation that continues for long enough eventually degenerates to bible recitation
16:24	technomancy	I tried to make it work as an OCaml joke, but it wasn't happening
16:26	hiredman	~#46
16:26	clojurebot	46. Like punning, programming is a play on words. -- Alan J. Perlis
16:30	arohner	are there any decent JVM libraries for process management? I'm looking to run `ps` and `kill` from clojure
16:30	brehaut	arohner: conch.sh
16:31	arohner	ok, let me rephrase that :-)
16:31	arohner	is there a decent library that will tell me "is there a process whose name matches regex", without having to parse the output of `ps -ef`?
16:31	pjstadig	probably not
16:32	pjstadig	the JVM isn't very unixy
16:32	arohner	k. I was hoping to avoid platform-specific output of ps
16:37	jtoy	is defonce lazy?
16:39	jtoy	meaning inside the defonce if i read a file and add create a hash will that happen upon the functino definition or when i call it?
16:41	technomancy	only seqs are lazy
16:41	technomancy	if you want to delay evaluation of non-seqs, you can use an explicit delay
16:42	devn	Have a feeling you cats will be interested in this kind of thing, or not: http://notonlyoo.org/
16:43	trptcolin	i read that as "not on YOLO" the first time
16:44	technomancy	oh no a manifesto
16:44	jimkcar	Let's go write some Java! #YOLO
16:44	Sgeo	"That is, while there is value in the items on the right (except for nulls), we value the items on the left more"
16:44	Sgeo	I like the hate on nulls
16:45	trptcolin	manifesto (n): Karl Marx's favorite core.logic function
16:45	technomancy	"✓ manifests over manifestos"
16:45	Sgeo	Um. Is the entire manifesto seriously "We like these over those other things?"
16:45	technomancy	Sgeo: that's all the Agile manifesto is too
16:46	brehaut	(inc trptcolin)
16:46	lazybot	⇒ 1
16:46	jimkcar	Blog page has swag for sale
16:46	brehaut	seriously? 1?
16:46	gfredericks	trptcolin: do you value reading over earning #clojure karma?
16:47	technomancy	brehaut: trptcolin doesn't connect to freenode often enough to bask in his well-earned repl glory
16:47	brehaut	technomancy: apparently so. i <3 reply
16:47	technomancy	which is too bad because it's a good source of vitamin D
16:48	trptcolin	it's a very exciting pronunciation
16:48	brehaut	TRPTCERLERN
16:49	ivan	arohner: maybe pgrep works on more platforms
16:49	Raynes	brehaut: ERMAHGERD
16:54	arohner	ivan: good idea, thanks
16:55	firefux	What's recommend today to connect to postgres from Clojure?
16:56	pppaul	datomic
16:57	Raynes	pppaul: Leave this channel and never return,
16:57	gfredericks	{:simple clojure.java.jdbc, :easy Korma}
16:57	brehaut	firefux: java.jdbc
17:00	abp	gfredericks: Korma can be simple too, but there are many simple things.
17:00	abp	At least simpler than writing sql.
17:00	gfredericks	sql is pretty simple.
17:00	pppaul	:D
17:00	abp	But verbose
17:00	brehaut	abp: ?? writing sql is really straight forward. its the reuse and composability of the written sql that is pants
17:00	abp	java can be pretty simple too :P
17:01	technomancy	SQL without syntax highlighting is a drag
17:01	abp	brehaut: Right, and I always compose my queries.
17:02	brehaut	technomancy: and writing SQL via an abstraction that isnt a clean match semantic match is also a drag :/
17:03	gfredericks	come on guys just use hibernate
17:03	technomancy	brehaut: https://mobile.twitter.com/collinvandyck/status/305031087896281088?p=v
17:03	gfredericks	the answer has been right in front of us the whole time
17:03	gfredericks	we just had our heads stuck too far up our parentheses to see it
17:03	brehaut	technomancy: lols
17:04	brehaut	gfredericks: the empty list literal is now an emoticon i cannot unsee :/
17:05	gfredericks	oh man I wasn't even thinking of that
17:10	brehaut	this is a longshot, but anyone got any idea how you specify optional fields in a map using core.typed? (where the key may not be present, rather than a nilable value)
17:13	hiredman	you need paradox absorbing buffers for your robot's head
17:16	brehaut	.toString comes from of Object in java, rather than some interface right?
17:17	metellus	Object has a default .toString but it's usually overridden
17:17	brehaut	right, but in terms of types if something is toStringable, its and Object rather than IStringable
17:17	metellus	yes
17:18	brehaut	thanks
17:20	canweriotnow1	what's the best way to handle native dependencies with leiningen, when packaging a library?
17:21	canweriotnow1	i.e., if a Java dependency has platform-specific *.so binaries?
17:35	akhudek	I added domina to the toggle class performance test included with dommy: {:domina 18.9, :jquery 11.412, :dommy 4.73}
17:40	konr	would it be a bad idea to port Backbone.js to ClojureScript?
17:43	akhudek	ok, just updated it by adding a proper toggle-class to domina that uses google closure's toggle function
17:43	akhudek	{:domina 4.465, :jquery 11.326, :dommy 4.621}
17:46	tomoj	konr: yeah
17:46	tomoj	:P
17:47	konr	tomoj: why?
17:50	tomoj	you either wind up with something ugly or something that isn't backbone
17:51	tomoj	it may well be a good idea, if only as an exercise
17:52	tjgillies	whats the best way to show exceptions in compojure?
17:54	nDuff	...hrm; clojure-mode is highlighting lines with errors/warnings on C-c C-k compile, but I'm unclear on how to see what those warnings actually _are_.
17:54	danneu	konr: dunno how it's a 'bad idea'. you're just replicating work and need to backport changes that happen on backbone master
17:55	danneu	sounds intellectually/educationally fun tho
17:55	squidz	i am trying to call a function for every node of an xml document where the function differs if the node is an end node or not. Whats the easiest way to do this in clojure?
17:55	hiredman	"end node"
17:56	squidz	hiredman: ?
17:57	squidz	right now I am maping said function over (xml-seq ..), but I am not sure if there is a function out there that returns true/false based on if an xml node is an end node or not
17:58	technomancy	canweriotnow1: unfortunately the process for creating those jars isn't documented currently; you have to read the source
17:58	technomancy	or copy an existing native jar
17:59	squidz	also, is there something out there that gives the depth of the xml node in xml-seq?
17:59	canweriotnow1	technomancy: is it still the native/target_os/target_arch schema?
18:00	technomancy	canweriotnow1: basically yeah
18:00	technomancy	every time someone asks, I tell them once they figure it out they should submit a pull request with documentation
18:00	canweriotnow1	also: I guess that means it's necessary to package native deps as a separate jar and add it to project.clj, I can't bundle them with my project?
18:01	canweriotnow1	hah, if I figure out a good way to do it, I'll definitely submit one!
18:01	danneu	squidz: im new to clojure but your requirements sound really simple http://www.gettingclojure.com/cookbook:xml-html
18:01	technomancy	canweriotnow1: yeah, that's usually how it's done. just a bunch of .so/.dll/whatever-mac-uses in a certain path structure in the jar
18:02	tomoj	clojurescript.test! woot
18:02	canweriotnow1	okay, thx... I wish maven handled this better :(
18:03	squidz	danneu: yeah that is pretty much what I have so far, but doesnt tell me how to figure out how deep I am in the xml
18:04	squidz	it looks like what I want is clojure.zip, but i cant seem to get it to work
18:05	ed_g	squidz: does end? not work for you?
18:06	squidz	ed_g: no, it is giving me a : string cannot be cast to IFn exception. Maybe it is because I am using xml-seq?
18:09	ed_g	squidz: I would guess so. by end node you mean node with no children? in a zipper it means the last node when traversing the zipper.
18:09	squidz	ed_g: okay I see I have to use xml-zip instead of xml-seq to be able to use end? but I am getting null pointer exceptions now
18:10	jtoy	how would split a string and have the first element in a variable and the remaining items in anothern variable?
18:11	canweriotnow1	technomancy: Thanks! It's ugly, but it worked!
18:12	canweriotnow1	(all this just to write a clj wrapper for Pam auth)
18:12	akhudek	jtoy: this is a very confusing question. If you split a string and get back a seq of results, the first element is (first results) and the rest would be (next results).
18:12	jtoy	my code for it is bad now: (let first_part (first (clojure.string/split line )) last_part (range 1 -1 (clojure.string/split line )) )
18:12	jtoy	akhudek: I mean like that
18:13	ed_g	squidz: it sounds like your definition of end node is similar to what you might also call a leaf node, that is a node with no children? do I have that right?
18:13	squidz	yes that is what I mean
18:13	akhudek	jtoy: split it once, and use first and next on the result
18:14	technomancy	canweriotnow1: ugly sounds about right
18:14	akhudek	jtoy: you can also use destructuring if you really want to be clever
18:14	ed_g	in which case you can iterate using xml-seq and look for nodes without :content
18:15	technomancy	at least you don't have to recompile it on every install like you do with rubygems though
18:15	akhudek	jtoy: (let [[f & r] (clojure.string/split line)] …)
18:16	canweriotnow1	ha, true!
18:17	jtoy	akhudek: hmm, that might be too advanced for me ,not sure what that does
18:17	danneu	akhudek: does clojure have a func that's like Enumerable#partition in Ruby/Scala? [1, 2, 3].partition { _ > 1 } #=> [[1], [2 3]]
18:17	akhudek	jtoy: all you need is first and next
18:17	ed_g	for instance (filter (fn [e] (empty? (:content e))) (xml-seq your-xml))
18:18	akhudek	jtoy: (let [result (clojure.string/split line) f (first result) r (next result)] … )
18:20	scottj	danneu: partition-by and group-by
18:21	squidz	ed_g: im trying it out. ill let you know if it works
18:22	nDuff	Hrm.
18:25	saolsen	Does anybody know off hand the state of clojurescript sourcemaps? I've been googling around and found a few different discussions on it but I can't tell.
18:26	ed_g	squidz: I wrote a version of map and filter for zippers which you might find useful just for experimenting, not sure where the paste page is for this channel but I can put them there
18:27	squidz	okay just send me the paste link
18:30	ed_g	http://pastebin.com/1QeuTpuf keep in mind that modifying a zipper this way is challenging.
18:31	tjgillies	im working with cheshire and monger
18:31	tjgillies	im requiring monger.json like in the docs
18:31	tjgillies	but cheshire/encode can't serialize the doc
19:09	amalloy	ed_g: huh? why have map-zipper and filter-zipper, instead of just mapping and filtering over a zip-seq?
19:12	ed_g	amalloy: because I didn't see zip-seq in my quick reference docs :-)
19:12	ed_g	actually I still don't -- what library is it in?
19:12	amalloy	ed_g: i don't know that it exists, but writing it yourself is preferable to writing map-zipper and filter-zipper
19:13	ed_g	amalloy: keep in mind these are basically the first functions I wrote in clojure
19:13	korny_	Hi - anyone here familiar with Liberator? We're trying to define a basic resource with a basic JSON representation, but it seems we have to explicitly call (json-str data) to get a json response
19:14	korny_	e.g. (defresource foo :handle-ok ["a" "b" "c"] :available-media-types ["application/json"]) gives an error
19:15	korny_	whereas :handle-ok (json-str ["a" "b" "c"]) works, but it seems strange to have to explicitly call this.
19:21	sshack	Is there a clojure library for parsing csv files that handles headers? I swear there was at one point, but can't remember the name now.,
19:24	scottj	saolsen: idk but I think status is not working but being worked on here and there when dnolen gets the time and motivation. see source-map branch on clojurescript repo maybe
19:29	jtoy	how do I turn a vector of items into a vetor of vectors? this doesnt work: (defn ts [i] [(map #([%]) i)]) ; (ts [1 2 3 4])
19:30	technomancy	jtoy: (vec (map ...))
19:30	technomancy	err
19:31	technomancy	(vec (for [i is] [i]))
19:31	jtoy	ok
19:31	jtoy	not sure what the difference is between map and for, seem almost the same
19:31	technomancy	map is a function that takes a function as an argument; for is a macro
19:31	hiredman	for can filter and concat
19:32	jtoy	ok, imtesting itthanks
19:33	technomancy	it can concat?
19:34	hiredman	,(for [a [[1 2] [3 4]] b a] b)
19:34	clojurebot	(1 2 3 4)
19:34	hiredman	concat
19:34	technomancy	oh, because of how it nests. yeah, never thought of it that way but it makes sense
19:35	hiredman	I just had an idea
19:35	hiredman	reducers/for
19:35	hiredman	that expands in to calls to the reducer fns
19:36	technomancy	you might say
19:36	technomancy	that I'm for it
19:36	technomancy	( •_•)
19:36	technomancy	( -_-)~⌐■-■
19:36	technomancy	(⌐■_■)>
19:37	hiredman	~clap
19:37	clojurebot	Gabh mo leithscéal?
19:38	hiredman	~applaud
19:38	clojurebot	excusez-moi
19:38	technomancy	I need to make an emacs defun for that because I was worried someone would respond in between lines
19:40	amalloy	hiredman: because having the entire implementation of the 'for macro copy/pasted into 'doseq wasn't bad enough
19:41	hiredman	amalloy: well, you can't do it as a c&p
19:43	hiredman	man, I never remember :while
19:43	hiredman	and I always try and use :where instead of :when
19:44	technomancy	:where would make more sense
19:45	hiredman	:where would be sql like
19:48	amalloy	hiredman: the tricky bit is remembering what :while does
19:49	amalloy	(for [x '[a b c] y [1 2 3 4] :while (< y 3)] [x y]) returns '([a 1] [a 2] [b 1] [b 2] [c 1] [c 2]), whereas it's easy to forget and expect it to just be '([a 1] [a 2])
19:49	hiredman	yeah, screw :while
19:55	hiredman	https://gist.github.com/5113363 fitting in the :when's would be tricky
19:56	sshack	So, clojure csv libraries?
20:14	sshack	Okay, question. How do I map a function with dirty > 1 ? Trying to do (map (nth 3) myseq)
20:14	sshack	In mathematica I'd do Map[nth[&,3], mylist]
20:14	sshack	& standing in for the mapped list.
20:14	lazybot	java.lang.RuntimeException: Unable to resolve symbol: standing in this context
20:15	root`	you want every third value from `myseq`
20:15	root`	?
20:16	sshack	root`: Well, each whatever value.
20:16	sshack	I've got a seq of seq's (rows from a csv file)
20:16	sshack	So I want to handle all the values of each type one at a time.
20:16	sshack	Do I make sense?
20:17	root`	sshack: yea, one sec
20:18	qbg	&(map #(nth % 2) [[1 2 3] [4 5 6] [7 8 9]])
20:18	lazybot	⇒ (3 6 9)
20:20	sshack	qbg: Perfect! Thanks.
20:20	qbg	&(apply map vector [[1 2 3] [4 5 6] [7 8 9]])
20:20	lazybot	⇒ ([1 4 7] [2 5 8] [3 6 9])
20:20	qbg	That might be useful for you too
20:22	sshack	qbg: That is actually
20:24	sshack	qbg: Is the JVM smart enough to not clobber memory resources doing that?
20:24	sshack	I'm thinking about 400meg csv files here.
20:25	qbg	How many columns do you have?
20:25	sshack	200 or less
20:25	sshack	few hundred thousand rows.
20:26	qbg	map is lazy, so the above might be sufficient
20:27	qbg	eh, got that backwards.
20:27	sshack	Cool. I'm trying to cut down the number of columns. Should be ~50-70 soonish.
20:27	qbg	apply map vector would yield some big vectors in that case
20:27	sshack	I have this in my toolbox: (def transpose
20:27	sshack	(partial apply map list))
20:28	qbg	that is the same as above :)
20:29	qbg	If you have a seq of seqs, you'll be walking the outer seek when processing each column
20:29	qbg	So almost certaintly you'll end up with the entire file in memory
20:30	sshack	Good point. I think the best approach is get the data into a DB first. Then deal with it there.
20:31	sshack	So now I have to remember the name of that CSV file that deals with headers.
20:31	qbg	db would work. You could also read the entire file multiple times
20:33	sshack	I've sort of been burnt dealing with CSV files (mathematica, python, etc). So I think I'll parse things into a normalized DB and then go from there.
20:44	ambrosebs	It might be useful, say if you had a seq of possibly nil Closeables, and you (map close! cseq)
20:44	ambrosebs	(doall ...) :)
20:46	ambrosebs	sorry wrong chat
20:50	alandipert	is there a slurp-binary or similar in someone's awesome lib somewhere?
20:50	alandipert	i have an input stream and know the length, would like to get a byte array w/ the stuff in it
20:51	qbg	There is a static method for that in apache commons io's IOUtils at least
20:57	Frozenlock	Is there a way to make everything in the repl pretty-printed?
20:59	alandipert	Frozenlock: it depends on how you're repl-ing; with lein repl i know you can do :repl-options [:print clojure.pprint/pprint] in your project.clj
21:00	alandipert	i've never tried to do it any other way though, maybe nrepl and swank can be configured similarly
21:00	Frozenlock	Thanks, that's exactly what I was looking for!
21:06	xeqi	alandipert: in clojars we use something like: (let [bs (java.io.ByteArrayOutputStream.)] (io/copy in bs) (.toByteArray bs))
21:06	xeqi	for a slurp-binary
21:07	alandipert	xeqi: oh, that's nice, len not required even. thanks!
21:12	Frozenlock	alandipert: I must have done something wrong... I see now difference :(
21:12	Frozenlock	*no
21:23	Frozenlock	Oh well.. (define-key map (kbd "C-c C-p") 'nrepl-pprint-eval-last-expression) .... should have read the nrepl.el sooner.
21:23	brehaut	do i have to officially ask for my jira privs to be bumped on the dev list, is someone just able to do it for me?
21:47	amalloy	if anyone important were in here, they could do it for you, brehaut
21:47	brehaut	amalloy: andy fingerhut did it on the list, but cheers
23:23	RazWelles	does clojureclr have any sort of introspection, like dir() for python?
23:23	RazWelles	also, how do you register event handlers?
23:33	noprompt	RazWelles: I'm not sure about the CLR version, but theres the doc function. You could try that
23:33	noprompt	,(doc map)
23:33	clojurebot	"([f coll] [f c1 c2] [f c1 c2 c3] [f c1 c2 c3 & ...]); Returns a lazy sequence consisting of the result of applying f to the set of first items of each coll, followed by applying f to the set of second items in each coll, until any one of the colls is exhausted. Any remaining items in other colls are ignored. Function f should accept number-of-colls arguments."
23:33	RazWelles	noprompt, I found something that kinda works... but now I'm at a loss for how to register an event handler :\
23:53	n_b	If I have a vec, is the more idiomatic way to access the last item in faster than linear time than doing (some-vec (dec (count some-vec)))?
23:55	n_b	I suppose (nth (dec (count some-vec)) some-vec)?
23:55	alandipert	n_b: peek may be what you want
23:55	RazWelles	ArgumentTypeException expected EventHandler`1, got EventHandler .CallSite.Target (:0)
23:55	RazWelles	Any idea what this means?
23:56	n_b	alandipert: That'd do it. Cheers!
23:56	jeremyheiler	n_b Maybe (first (rseq [1 2 3]))?
23:57	jeremyheiler	ahihi, didn't see your reply there, alandipert
23:57	jeremyheiler	Ah*