#clojure – 2011-09-13

2011-09-13

00:12	srid	is it possible to trace javascript errors (in browser) down to cljs source line no?
00:13	amalloy	seems unlikely, srid, but i guess i'm not the expert
00:23	dnolen	srid: not yet no, you need source mapping for that.
02:08	antares_	hi. I have a type hint inside a syntax-quoted form, like this: (String. ^bytes message-payload#) and compilation fails with "Unable to resolve classname: clojure.core/bytes". What do I do? without this type hint, String ctor cannot be determined.
02:15	amalloy	^"[B" should work
02:17	amalloy	^bytes is a convenience that i guess the syntax-quoting system might not know about
02:25	antares_	amalloy: thanks. I ended up with ~(with-meta v { :tag bytes }) where v is generated with gemsym.
02:29	tsdh	Is there a way to programmatically generate strings containing nested #=() forms? I want to generate something like "#=(+ 1 #=(+ 2 3))", but don't get it...
02:36	tsdh	Ah, got it using format instead of str.
02:36	ambroff	anyone have any idea how to use into-array to create a byte[][]? I can't figure out how to name the byte[] type.
02:37	amalloy	&(class (into-array [(make-array Byte/TYPE 1)]))
02:37	lazybot	⇒ [[B
02:37	ambroff	I have a sequence of byte[] objects and I want to turn it into a two dimensional array so I can invoke a variadic method that takes byte[]… as a parameter
02:37	ambroff	oh thank you amalloy!
02:38	amalloy	really though if you have a sequence of byte[]s, just a plain old into-array should work?
02:39	amalloy	tsdh: i think chouser is right; trying to do a bunch of code evaluation in the reader is madness
02:40	tsdh	amalloy: Most probably he is right, but as long as I don't have a better solution...
02:52	tsdh	amalloy: This works flawlessly (http://pastebin.com/4QAhwJWp) and allows me to read and write arbitrary clojure data structures containing instances of those custom 2 java classes. Although not very clean, I don't see how to do it otherwise. But I'm still open for suggestions.
03:00	thorwil	hmm, if i start appengine-magic from a lein repl, i can use datastore ops fine. but via swank, after clojure-jack-in, i get: No API environment is registered for this thread.
03:24	thorwil	ok, so i learned slime-eval-buffer and pasting to the repl makes a difference, there :)
04:03	Jeffrey04	good evening~
04:04	Jeffrey04	i just threw 10mil of lines into my script and it throws OutOfMemoryError (-Xmx2G), is there anyway I can rewrite the code so that it doesn't use up all the memory?
04:04	Jeffrey04	http://stackoverflow.com/questions/7186663/clustering-fkmeans-with-mahout-using-clojure < the first clojure script
04:05	Jeffrey04	10mil lines of input from stdin*
04:05	Jeffrey04	clojure 1.3-snapshot if this is relevant
04:12	Fossi	Jeffrey04: seems like something isn't lazy (prolly the java part)
04:13	Fossi	so it realizes the whole seq when trying to pass that on
04:13	Fossi	you can try to force evaluation (doall) earlier to see what consumes too much memory on the way
04:14	Jeffrey04	Fossi: not sure, I don't even know where to begin debugging ;/
04:15	Fossi	Jeffrey04: i don't get the domain at all, but i assume you want to read some lines, crunch them and spit them out again then continue?
04:16	kzar	I wanted to fix a typo in a 4clojure problem but the source in Github seems to only go up to problem 87. Where's the latest version?
04:19	Jeffrey04	Fossi: it first turn the first block in the stackoverflow.com post into something like this: { tag_sit [image_a 0 image_b 1] tag_lorem [image_a 1 image_b 0] ...}
04:19	Jeffrey04	then it will continue processing them
04:20	Jeffrey04	suspecting the inner reduce call is killing the script
04:21	Fossi	Jeffrey04: so you want all the data in memory at once?
04:22	Fossi	what i meant above was: turn the inner reduce into a method, and test-call that with doall
04:22	Fossi	and see if that already fails
04:23	Jeffrey04	probably not, thinking of caching them into temp file
04:23	Fossi	so you know whether that "first" step already fails
04:24	Fossi	because with "normal" evaluation all the seqs will be sazy
04:24	Fossi	*lazy
04:24	Fossi	and it will fail just at passing it down to java on realizing the whole map/reduce construct
04:27	Jeffrey04	ok
04:27	Jeffrey04	let me try
05:46	fliebel	Does ClojureScript have its own channel and mailing list?
05:51	fliebel	Ah https://groups.google.com/forum/#!topic/clojure/3b77dCMuvQs
05:54	michaelr525	hey
05:54	fliebel	michaelr525: Hi
05:54	michaelr525	what's up? :)
06:03	tsdh	Do I see it correctly that in clojure 1.3 ^:dynamic vars rebound with `binding' will have the rebound value in all threads spawned in the dynamic scope of the `binding'?
06:06	raek	only with clojure's own constructs, like 'future'
06:07	tsdh	raek: Of course, that's what I've used to test my assumption. :-)
07:16	thorwil	where does output from println end up, with a swank session started via clojure-jack-in?
07:18	raek	thorwil: for expression evaluated from the repl thread, they should end up in the repl. in other threads they end up at the top of the buffer called something with "swank" in it
07:19	raek	you might want to do a (intern 'clojure.core 'out out) in your repl
07:22	thorwil	raek: that did the trick, thanks!
07:23	thorwil	before, there was no output in the repl and wild mix of looging in swank (without print output)
07:26	thorwil	now if server messages keep out of the swank repl, this might actually be worth the move away from running a lein repl for appenegine-magic/jetty plus swank
07:48	bendlas	I'm having an issue with connecting Eclipse + CCW to an external nRepl
07:48	bendlas	It works, basically, but autocompletion throws an error
07:48	bendlas	anybody seeing the same, or knows how to fix?
08:11	pphant	afternoon - can anyone explain why :arglists metadata only appears after I call defn twice?
09:41	tsdh	Wow, the canonical lazy fibonacci sequence example performs fife times faster than a straight-forward iterative java solution. http://pastebin.com/DwFqADLs
09:42	tsdh	Why is that? Because clojure starts the calculation with longs and promotes to slower BigInt ops only later on?
09:43	opqdonut	I guess yeah
09:43	opqdonut	try using BigInteger.ZERO and ONE instead of 0 and 1 in the clojure version and see what happens
09:47	tsdh	opqdonut: Hm, it's still as fast as before using 0N 1N...
09:49	michaelr525	compiler optimization maybe
09:49	michaelr525	i mean maybe it still compiles to integer
09:51	tsdh	Or clojure.lang.BigInt simply performs better than java.math.BigInteger.
10:05	TimMc	clojure.lang.BigInt... new in 1.3?
10:05	TimMc	yes, it is
10:06	TimMc	"unlike BigInteger, BigInt has consistent hashcodes with Long, through range of long"
10:11	michaelr525	cool
10:31	leeda	doesn't clojure core have a recursive merge for maps?
10:34	michaelr525	i found this: http://clojuredocs.org/clojure_contrib/clojure.contrib.map-utils/deep-merge-with
10:35	michaelr525	leeda: ^^
10:35	leeda	basically i want to do this: (merge {:a {:z 1}} {:a {:a 1 :b 1}}) -> {:a {:a 1 :b 1 :z 1}}
10:36	leeda	,(merge {:a {:z 1}} {:a {:a 1 :b 1}})
10:36	clojurebot	{:a {:a 1, :b 1}}
10:36	leeda	michaelr525: hm looks like it might work, wonder what function i should use
10:37	michaelr525	,(require 'clojure.contrib.map-utils)
10:37	clojurebot	#<RuntimeException java.lang.RuntimeException: java.io.FileNotFoundException: Could not locate clojure/contrib/map_utils__init.class or clojure/contrib/map_utils.clj on classpath: >
10:37	jli	is there a way to turn off pull requests in github? hopefully people don't just think clojure is ignoring them
10:37	michaelr525	leeda: maybe identity
10:37	leeda	surprised there's nothing in clojure.core though
10:37	jkkramer	,(merge-with merge {:a {:z 1}} {:a {:a 1 :b 1}}) ;for one-level deep
10:37	clojurebot	{:a {:b 1, :a 1, :z 1}}
10:37	leeda	michaelr525: yeah i'll try that
10:37	leeda	jkkramer: oh haha that works
10:38	leeda	jli: wait why would you want to do that?
10:38	jli	leeda: because contributors have to sign a CA, and the channels for contributing are via JIRA
10:39	leeda	jli: ah ok
10:39	raek	Clojure has it's own issue tracking system and does not accept patches outside the system
10:39	redinger	jli: As far as I know we cannot turn off pull requests
10:39	redinger	Or at least, I don't see such an option
10:39	jkkramer	it lets you turn off issues, which may in turn disable pull requests
10:40	redinger	We've turned off issues
10:41	jkkramer	too bad github itself doesn't accept pull requests
10:44	jli	I guess someone would could just close them manually
10:45	jli	with a link to the contributing page
10:47	TimMc	jkkramer: Isn't github on github?
10:47	TimMc	Maybe it is in a private repo.
10:47	jli	I don't think it is
10:48	TimMc	I guess they don't want people forking them.
10:48	jli	yeah, not publically at all
10:48	jkkramer	github-the-company is, github-the-site is not
10:48	jli	publicly at least*
10:48	TimMc	I think some of their components are public.
10:51	hugod	the github wiki (gollum) is on github
10:55	hugod	oh, and I see they now have a github maven plugin, with goals for uploading artifacts to a project's download area on gihub, and to publish to gh-pages
11:49	michaelr525	anyone here uses ERC for IRCing?
11:50	michaelr525	how to get the number of people in the channel?
11:50	Scriptor	there's some elisp script you have to install, it's not bundles afaik
12:01	technomancy	michaelr525: (hash-table-size erc-channel-users)
12:02	technomancy	what I wouldn't give for a reasonable associative data structure in elisp =(
12:04	hugod	what rhickey hoped he'd never see? https://github.com/pallet/zi-cljs
12:09	ambrosebs	hugod: he knew someone would do it ;)
12:10	michaelr525	technomancy: hey thanks!
12:10	michaelr525	err
12:11	mdeboard	Why didn't he want to see that?
12:11	mdeboard	Does it compile to JVM bytecode ?
12:11	michaelr525	technomancy: can i just eval it while in the irc buffer?
12:11	mdeboard	or?
12:11	technomancy	michaelr525: M-:, yeah. it's buffer-local.
12:11	mdeboard	@ hugod ambrosebs
12:11	mdeboard	oh, uh
12:11	mdeboard	I remember from the "introducing cljs" talk
12:12	michaelr525	technomancy: ok, i need you to hold my hand :) how do it do it?
12:13	technomancy	michaelr525: just hit M-: from the ERC buffer you want to count and enter the expression above.
12:13	mdeboard	what was it? no in-browser execution?
12:13	hugod	mdeboard: no, it just runs the clojurescript compiler - but it uses clojurescript, closure-compiler and the closure library from jars
12:13	mdeboard	hugod: Why is that negative? I don't get it, I guess, but want to :P
12:14	technomancy	hugod: anything would be an improvement over "be sure to set CLOJURESCRIPT_HOME before you do anything"
12:14	technomancy	gives me flashbacks to hadoop =\
12:15	hugod	technomancy: I don't think you have to do that anymore - my patch to infer clojurescript_home from the script path was applied across the board, I believe
12:15	michaelr525	201 Origin Ocean Additional Currency 1 (null) ORIGIN_OCEAN_ADDON_CURRENCY 0 1 1 1 1 1 4
12:15	technomancy	hugod: oh good
12:16	michaelr525	technomancy: thanks
12:17	hugod	mdeboard: I don't think it is negative - just some people dislike maven…
12:17	mdeboard	hugod: Oh ok, thought you were referring to the distaste (iirc) for in-browser evaluation
13:15	dbushenko	you guys!
13:16	dbushenko	#lisp has only 345 users, while #clojure -- 347!
13:16	mdeboard	yeah that's how trends work :P
13:17	dbushenko	this winter #clojure had just about 200-220 on the average
13:17	dbushenko	clojure gains popularity!
13:18	SergeyD	hi, where is defmacro in 1.3? I got a strange error that about clojure.contrib.def/defmacro after I removed the clojure contrib jar. Though I do not use or require clojure contrib anymore
13:20	SergeyD	Sorry, I was probably wrong
13:20	SergeyD	Just "defmacro" in REPL works
13:50	mattmitchell	Is there a nice alternative to this: (apply concat (map :id (map :records data))) => yields a list of ids from {:records [{:id 1}]} ??
13:50	lazybot	mattmitchell: Uh, no. Why would you even ask?
13:50	mattmitchell	well hrm
13:51	mdeboard	lol @ smart-aleck lazybot
13:51	amalloy	heehee
13:51	mattmitchell	lazybot: How was I to know?
13:51	mattmitchell	:)
13:51	TimMc	haha!
13:51	TimMc	It got me that time.
13:52	TimMc	mattmitchell: data is [{:records ...}] presumably
13:52	amalloy	mattmitchell: do you mean [{:records [{:id 1}]}]? your (map :records) doesn't make sense otherwise
13:53	mattmitchell	amalloy: oh yes sorry
13:53	mattmitchell	hmm, bad example
13:53	mattmitchell	Let me think of another
13:54	TimMc	Perhaps you are looking for some kind of tree-walk thingum.
13:55	TimMc	Hrm... maybe that's too general
13:55	amalloy	&(let [data [{:records [{:id 1}, {:id 2}]}] (for [{records :records} data, {id :id} records] id))
13:55	lazybot	java.lang.IllegalArgumentException: let requires an even number of forms in binding vector
13:55	amalloy	&(let [data [{:records [{:id 1}, {:id 2}]}]] (for [{records :records} data, {id :id} records] id))
13:55	lazybot	⇒ (1 2)
13:56	TimMc	Oh, there's that flatten aspect of for again.
13:56	mattmitchell	TimMc: yes something like that, extract a flat list of values for a certain attribute, where the attribute is in a nested structure
13:56	TimMc	mattmitchell: Looks like amalloy nailed it.
13:57	mattmitchell	Oh I see. Yeah that's nice.
13:58	mattmitchell	amalloy TimMc thanks!
13:58	TimMc	,(inc amalloy) for reminding me that for can descend more than one layer
13:58	clojurebot	#<CompilerException java.lang.RuntimeException: Unable to resolve symbol: amalloy in this context, compiling:(NO_SOURCE_PATH:0)>
13:58	TimMc	&(inc amalloy) then
13:58	lazybot	java.lang.Exception: Unable to resolve symbol: amalloy in this context
13:59	amalloy	TimMc: for is fantastic. i use it in like every other function
13:59	TimMc	amalloy: Sorry, you don't exist.
14:01	mattmitchell	wow, how does that "for" example even work? Need to dig into "for" now.
14:01	TimMc	mattmitchell: A for with n bindings is like n nested for loops.
14:02	mattmitchell	TimMc: So your list of bindings can reflect the nesting?
14:02	TimMc	Yup.
14:03	mattmitchell	Very awesome
14:03	TimMc	Each binding can use the bindings before it. You can use it for recursive descent, like amalloy did, or cartesian products if the second binding doesn't use the first.
14:03	mattmitchell	Nice, thanks
14:03	TimMc	,(for [a [1 2 3], b '[x y]] [a b])
14:03	clojurebot	([1 x] [1 y] [2 x] [2 y] [3 x] ...)
14:04	mattmitchell	Ahh OK. Good example.
14:05	amalloy	&(let [items '[a b c]] (for [x items y items :when (not= x y)] [x y]))
14:05	amalloy	is another example of useful stuff you can do with `for`
14:05	lazybot	⇒ ([a b] [a c] [b a] [b c] [c a] [c b])
14:06	TimMc	haha, nice!
14:06	mattmitchell	Cool
14:06	TimMc	Very readable.
14:06	amalloy	&(let [items '[a b c]] (for [x items y items :while (not= x y)] #{x y})) ; no duplicates
14:06	lazybot	⇒ (#{a b} #{a c} #{c b})
14:07	amalloy	that might be the first time i've ever wanted to use :while, though - i find :when and :let a lot more useful
14:21	mattmitchell	is there a nice way to know if a number falls within a given range?
14:22	amalloy	&(< 5 8 10)
14:22	lazybot	⇒ true
14:22	amalloy	&(< 5 22 10)
14:22	lazybot	⇒ false
14:22	hiredman	,(.contains (range 10) 8) ;; don't do this
14:22	clojurebot	true
14:23	mattmitchell	hiredman: nice one :)
14:23	amalloy	heh
14:23	mattmitchell	amalloy: man, why does it always look so simple?
14:23	amalloy	,(contains? (range 10) 8) ;; much more efficient!
14:23	clojurebot	false
14:23	amalloy	(also wrong of course)
14:24	pdk	(doc contains?)
14:24	clojurebot	"([coll key]); Returns true if key is present in the given collection, otherwise returns false. Note that for numerically indexed collections like vectors and Java arrays, this tests if the numeric key is within the range of indexes. 'contains?' operates constant or logarithmic time; it will not perform a linear search for a value. See also 'some'."
14:24	pdk	:\|
14:49	kjeldahl`	Anybody ready for a Congomongo question? git://gist.github.com/1214676.git
14:49	kjeldahl`	In essence enforcing a unique index and detecting when an insert fails.
14:50	mattmitchell	Curious about a more idiomatic way to do this, anyone have any suggestions? https://gist.github.com/1214682
14:51	mattmitchell	It removes :rates items if the :total_rate falls outside the min-rate and max-rate
14:52	amalloy	mattmitchell: i smell a for/when pattern...
14:52	mattmitchell	that's what I was wondering
14:57	amalloy	i guess there are a number of ways you could do this
14:57	amalloy	https://gist.github.com/1214703 is a rewrite with for/when
14:58	amalloy	you could also do something like...map over the collection with an update-in that fixes the :rates key, and then filter for non-empty :rates keys
15:00	mattmitchell	amalloy: Really nice, thanks! :)
15:05	amalloy	clojurebot: ping
15:05	clojurebot	PONG!
15:12	zippy314_	Hi. Looking for help interpreting the syntax of the cyclic load deps warning under 1.2.1: Cyclic load dependency: [ /anansi/streamscapes/streamscapes ]->/anansi/streamscapes/ident->[ /anansi/streamscapes/streamscapes ]->/anansi/streamscapes/channel->/anansi/test/streamscapes/channel
15:12	zippy314_	Am I supposed to read that backwards?
15:13	zippy314_	wondering what the [ ] mean.
15:33	seancorfield	pastebin the use/require clauses from each of those namespaces for us to look at?
15:34	scgilardi	[ ] highlights the path that the loader attempted to load twice
15:35	scgilardi	it reads forward
15:36	arohner	I have a clj file that takes 5-10s to compile in swank, when normally things take 0.01s. The file is not unusually long (50 LoC), but imports several java classes.
15:36	arohner	is there anything I can do about that? is it a known issue?
15:36	amalloy	arohner: it probably compiles in no time at all, then wastes a bunch of time printing status messages
15:36	amalloy	try (setq font-lock-verbose nil)
15:37	arohner	amalloy: no change. It takes 5s before the …….. shows up
15:40	amalloy	dunno, then. maybe technomancy has seen it before
15:41	grim_radical	how would i test if a variable is a java array? i can't seem to find an array analog to things like coll?, string?, etc
15:41	amalloy	&(.isArray (class []))
15:41	lazybot	⇒ false
15:41	hugod	arohner: how are you compiling it in swank?
15:41	grim_radical	amalloy: ah, of course...thanks!
15:41	arohner	hugod: C-c C-k
15:42	amalloy	&(.isArray (class (into-array ["test"])))
15:42	lazybot	⇒ true
15:44	mccraig	i have a lazy-seq of vectors… is there a stdlib function that will give me a lazy-seq of the concatenation of those vectors ?
15:45	chouser	,(apply concat '([1 2 3] [4 5 6] [7 8 9]))
15:45	clojurebot	(1 2 3 4 5 ...)
15:45	mccraig	chouser: but that does not seem to be lazy…
15:45	hugod	arohner: have you tried calling load-file from the slime repl? is that what the 0.01s is?
15:45	Chousuke	it is
15:46	chouser	mccraig: it should be "mostly" lazy -- not quite as lazy as it could be with a more specific function iirc.
15:46	arohner	hugod: load-file takes 1s
15:46	clojurebot	I don't understand.
15:46	Chousuke	,(take 1 (apply concat (repeat [1 2 3])))
15:46	clojurebot	(1)
15:46	mccraig	chouser: it seems to evaluate the entire contents of my lazy-seq of vectors
15:47	Chousuke	as you can see, it doesn't :)
15:47	Chousuke	are you sure you're not forcing evaluation somewhere else?
15:47	arohner	hugod: actually, it varies, 1s to 10s
15:47	chouser	mccraig: it probably forces the first 2 or 3 steps of the lazy seq initially
15:48	hugod	arohner: lots of gc?
15:48	Chousuke	hmm
15:48	Chousuke	,(take 1 (apply concat (repeat [(do (print "hey") 1) 2 3])))
15:48	clojurebot	hey
15:48	clojurebot	(1)
15:49	pcavs	,doc repeat
15:49	clojurebot	#<CompilerException java.lang.RuntimeException: Can't take value of a macro: #'clojure.repl/doc, compiling:(NO_SOURCE_PATH:0)>
15:49	Chousuke	hm, duh
15:49	Chousuke	just realised my experiment doesn't quite work .P
15:49	Chousuke	oh well
16:01	mccraig	chouser Chousuke : you are right… it is evaluating the first 3 steps of the lazy seq, and since the test seq only has 3 steps, i took that to mean it was evaluating all steps : thanks
16:13	rata_	hi
16:14	rata_	how can I specify the groupid of a package from maven central in project.clj?
16:15	arohner	rata_: in dependencies [group-id/artifact-id "version"]
16:15	rata_	arohner: ok, thanks =)
16:24	TimMc	amalloy: ##(contains? (set (range 10)) 8) much better :-P
16:24	lazybot	⇒ true
16:24	amalloy	not nearly as efficient though
16:25	TimMc	Yours efficiently returned the wrong answer.
16:25	clojurebot	llahna: anyway the answer is no. you can use #(some-fn %1 default-arg %2), for example
16:25	amalloy	TimMc: yeah, that was the whole fun of it
16:26	amalloy	clojurebot: llahna: anyway the answer?
16:26	clojurebot	llahna: anyway the answer is no. you can use #(some-fn %1 default-arg %2), for example
16:27	amalloy	brilliant
16:54	TimMc	clojurebot: yeah?
16:54	clojurebot	excusez-moi
16:54	TimMc	wait, nvm
17:40	arohner	is it possible to ask for the list of all loaded classes? Does that make sense on the JVM?
17:41	companion_cube	it may load the "list" class, hence modifying the observed state :)
17:42	brehaut	arohner: looking at the ClassLoader (http://download.oracle.com/javase/6/docs/api/java/lang/ClassLoader.html) methods, it doesnt appear to be obvious if it is possible
17:42	technomancy	arohner: I don't think you can distinguish between classes that have been loaded vs classes that are just on the classpath
17:42	technomancy	because it's supposed to be transparent
17:42	amalloy	chouser: looks like data.xml is set up to be built by hudson, but the builds have been failing; is that accurate? i don't understand hudson
17:42	joegallo	if this isn't out of date: http://www.javaworld.com/javaworld/javaqa/2003-07/02-qa-0725-classsrc2.html
17:43	joegallo	then you might could wallhack that field and read it off the some of the usual suspect classloaders
17:43	joegallo	but that's not appropriate for, like, real code
17:43	ieure	Is there a way to create a thing like a Python generator with Clojure?
17:44	arohner	my goal is to make a find-class that works similar to find-doc. I could deal with loading all classes, but I'd prefer not to
17:44	arohner	thanks all
17:44	brehaut	ieure: do you mean a function that yields items one by one, or do you mean the iterable object that is returned by that function?
17:44	joegallo	http://download.oracle.com/javase/6/docs/api/java/lang/instrument/Instrumentation.html
17:44	joegallo	has a getAllLoadedClasses() :)
17:44	ieure	brehaut, Well, both, but I am more interested in the former.
17:45	amalloy	ieure: lazy-seqs are isomorphic to generators, really, i think
17:45	brehaut	ieure: theres no direct analogy, but the lazy-seq macro is what you are looking for
17:45	brehaut	amalloy: nah, seqs are superior in about every way to generators
17:46	ieure	brehaut, It’s not clear from the docs that it is, but they are often difficult to grasp in their terseness.
17:46	ieure	The docs make it seem more like it is memoizing.
17:47	ieure	So basically I want to stitch together paginated results into a single seq.
17:47	ieure	But I don’t know the offset of page N' until I have consumed page N.
17:47	brehaut	ieure: the big difference is that generators are iteratively defined, and lazy-seqs are recursively defined. inside a lazy-seq cons is roughly equivalent to yield in python
17:48	technomancy	ieure: you may be able to even just (apply concat (for [...]))
17:48	ieure	technomancy, Maybe.
17:48	ieure	brehaut, Interesting perspective.
17:48	ieure	I need to meditate on this.
17:48	brehaut	ieure: oh, there is one thing that generators can do that i dont think seqs support: generators can have a value 'sent' back into the generator function
17:49	ieure	brehaut, Yeah. Though that is not something I need.
17:50	ieure	So, if I create a lazy-seq that produces the results I want, does it: a) perform all the requests for pages the first time I begin to consume it, or b) perform the requests for page N as I consume across page boundaries?
17:50	amalloy	brehaut: explain
17:50	amalloy	?
17:50	brehaut	amalloy: which part?
17:51	amalloy	generators can have a value 'sent' back into the generator function
17:51	hiredman	ieure: it depends how you construct it
17:51	ieure	From the docs, it appears that A is the case, whereas I want B.
17:51	hiredman	lazy seqs don't know anything about "pages" whatever those are, but if you construct it in a way that knows about pages then yes
17:53	ieure	hiredman, It’s unclear to me how I would do it. Can you point me to an example?
17:53	joegallo	it would be pretty misleading to call it a "lazy" seq if the answer were a, i think :)
17:53	ieure	joegallo, Okay, but this is the only interpretation I can get from the docs.
17:53	ieure	"Takes a body of expressions that returns an ISeq or nil, and yields
17:53	ieure	a Seqable object that will invoke the body only the first time seq
17:53	ieure	is called, and will cache the result and return it on all subsequent
17:53	ieure	seq calls."
17:53	ieure	Sounds like memoization, not lazy/infinite seq creation.
17:54	hiredman	ieure: what if the body is a cons?
17:54	ieure	hiredman, I don’t know, what if it is?
17:54	brehaut	amalloy: heres a trivial example: def foo():\n a = True\n while a:\n i = yield 1\n\n
17:54	ieure	hiredman, Is a cons an ISeq or nil?
17:54	hiredman	ieure: well read that again with s/body/cons/
17:55	brehaut	amalloy: i = foo()\ni.next() # => 1\ni.send(False) # => StopIteration exception thrown
17:55	brehaut	#python must be an extremely frustrating place
17:55	ieure	brehaut, It’s not, really.
17:56	ieure	I just have not internalized the Clojure way as fully as I have Python.
17:56	brehaut	ieure: there must be a better way to post example code then.
17:58	amalloy	brehaut: btw, ; is equivalent to \n and makes the code a little more readable :P
17:59	brehaut	amalloy: sure :P
17:59	brehaut	amalloy: the indentation isnt very fun though
18:00	amalloy	i don't think i understand the send() yet. does that mean that the generator continues as if "yield 1" returned False?
18:00	brehaut	yeah, the return value for yield is the result of send
18:00	brehaut	it turns a generator into an annoying coroutine
18:31	gfredericks	hrm. I'm trying to run the clojurescript tests (script/test) and it wants a V8_HOME.
18:32	gfredericks	so I download and build v8 and set V8_HOME to that directory, and it says:
18:32	gfredericks	script/test: line 9: /home/user/v8-read-only/d8: No such file or directory
18:33	gfredericks	oh I see v8 has a "d8" build target....
18:40	srid	my web app works flawlessly with clojure-1.3.0-RC1, but what's with the "not declared dynamic and thus is not dynamically rebindable, but its name suggests otherwise" warnings?
18:40	brehaut	srid: you have earmuffs on a var name
18:41	srid	"Warning: append not declared dynamic [...]" <- that's a core function, no?
18:41	brehaut	srid: but havent added the :dynamic meta; earmuff var names indicate that they are ok to rebind
18:41	srid	ah, i am yet to read upon on 'bindings'.
18:42	srid	brehaut: maybe the "append" is coming from some other library, but the warning doesn't tell source location at all.
18:42	brehaut	it like is
18:42	brehaut	s/like/likely/
18:42	lazybot	<brehaut> it likely is
18:42	brehaut	i dont know how to find out sorry
18:51	patchwork	hey #clojure, I just ran a lein deps and it is missing the [org.clojure/java.jdbc "0.0.3-SNAPSHOT"] artifact? I ran it yesterday and it was there. Any reason why it would go missing?
18:51	seancorfield	you need to specify the sonatype repo to pick up snapshots
18:52	seancorfield	java.jdbc is at 0.0.6 right now on maven central
18:52	technomancy	from what I understand snapshots aren't even guaranteed to stick around anyway
18:53	seancorfield	0.0.3-SNAPSHOT would be very old, so you may be right technomancy
18:54	seancorfield	the only snapshot i'm relying on right now is congomongo because we're a bit lax about making non-snapshot releases :(
18:55	patchwork	Aha, gotcha. Thanks!
18:56	patchwork	I will update it
18:56	patchwork	I was going off the instructions for the heroku clojure install
19:03	seancorfield	i'm surprised that refers to a snapshot (given that i had to do fixes to support postgresql for that)
19:03	patchwork	http://devcenter.heroku.com/articles/clojure-web-application
19:04	patchwork	possibly the page just needs to be updated?
19:04	seancorfield	yeah, i'll ping aaron about that
19:42	srid	why are the key/value pairs reversed in map destructuring? eg: (let [{x 2, y 5} {2 "hello", 5 "foo"}] [x y])
20:01	amalloy	technomancy: i'm trying to upgrade to 1.3 but can't get either cake or lein to run swank properly. i assume someone's managed to do this already; what do i need to do? i've tried $ lein plugin install swank-clojure 1.4.0-SNAPSHOT, but still $ lein swank seems to have issues: https://gist.github.com/1215517
20:02	hiredman	check for old versions of swank in lib
20:02	hiredman	but that is actually a problem with contrib
20:02	technomancy	amalloy: I haven't tried 1.3 since ~alpha2, but I also haven't heard anyone else mention that
20:03	technomancy	swank does have some "let's use this contrib functionality if it's on the classpath" features
20:03	hiredman	some dependency is transitively compiling clojure.contrib using 1.2
20:03	hiredman	then packaging up the classfiles which are not abi compatible with 1.3
20:04	amalloy	hiredman: yes, i haven't yet hunted down which of my deps depend on contrib; i was hoping to use swank to help me find them
20:04	hiredman	well, this is something that is aot compiled
20:04	amalloy	maybe mvn will tell me?
20:28	seancorfield	Q about reflection warnings... Given this code: (let [c (.charAt "Hello" 2)] (println (type c)) (= c \l))
20:28	seancorfield	(= c \l) gives a reflection warning that equiv can't be resolved
20:29	seancorfield	it prints Character (but String.charAt(int) returns char)
20:29	bhenry	,(let [c (.charAt "Hello" 2)] (println (type c)) (= c \l))
20:29	clojurebot	java.lang.Character
20:29	clojurebot	true
20:30	seancorfield	,(set! warn-on-reflection true)
20:30	clojurebot	#<IllegalStateException java.lang.IllegalStateException: Can't change/establish root binding of: warn-on-reflection with set>
20:30	seancorfield	bah
20:30	bhenry	ah
20:31	hiredman	= is being inlined as (. clojure.lang.Util equiv c \l)
20:32	hiredman	I doubt there is a Character, char overload for equiv
20:32	hiredman	that is rather unfortunate
20:32	seancorfield	fwiw i tried (= c (Character. \l)) but that also complained it couldn't resolve equiv
20:33	hiredman	oh whoops
20:33	hiredman	char, char
20:33	hiredman	charAt returns a primitive char
20:35	seancorfield	ah my bad - \l is Character, c is char
20:35	seancorfield	if i wrap c as (Character. c) it work
20:35	seancorfield	s
20:36	hiredman	yeah
20:36	hiredman	equiv really needs overloads for every combination of all primitives and Object
20:39	seancorfield	maybe i'd do better working with code points instead...
20:43	acuozzo	Hi, I've done some googling, but nothing's turned up. Is there a standalone clojure beautifier/formatter?
20:45	technomancy	acuozzo: not really
20:45	dnolen	acuozzo: Clojure has a pretty printer though I think someone really needs to do some work to make it print really well formatted Clojure source.
20:45	dnolen	acuozzo: it works well enough for macroexpansion in Emacs.
20:45	acuozzo	Ah, OK. I was hoping to plug something into my editor (nvi -- the BSD-licensed vi clone).
20:46	acuozzo	Thanks :-)
20:46	technomancy	the clojure.pprint is a start, but it's not usable out of the box
20:46	acuozzo	I suppose that it needs to be tweaked some?
20:47	acuozzo	Also, I noticed the clojure-refactoring project on Github (I think it was Github, at least). Has anyone toyed with turning this into a standalone CLI refactoring tool?
20:51	scottj	acuozzo: nothing released. I think the non-elisp parts were extracted to parsley
20:51	acuozzo	Is parsley on Github?
20:52	acuozzo	Yes, it is. Looking now
21:37	drewolson	this may not be the right place, but i'll take a shot: anyone know a good way to go about getting your clojars password reset? I sent an email a few days ago but haven't heard anything back.
22:50	srid	could someone tell me where in this code is the compiler error "ClassCastException: clojure.lang.PersistentVector cannot be cast to java.lang.Number" coming from? clojure compiler error messages are so unhelpful. http://dpaste.com/614485/
22:54	dnolen	,(+ 1 [])
22:54	clojurebot	#<ClassCastException java.lang.ClassCastException: clojure.lang.PersistentVector cannot be cast to java.lang.Number>
22:54	dnolen	,(<= 1 [])
22:54	clojurebot	#<ClassCastException java.lang.ClassCastException: clojure.lang.PersistentVector cannot be cast to java.lang.Number>
22:54	dnolen	srid: ^
22:55	dnolen	srid: that exception should give you a precise line number as well.
22:55	srid	dnolen: oh, yes, that's what I thought at first. but neither x nor n in `(<= x n)` are vectors.
22:56	joegallo	on the second recursive call (that is, the third call overall), x is a vector.
22:56	srid	n is always a number. and x cannot be a seq (because, it must be matched by the above cond)
22:56	joegallo	[3 [4 5] 6]
22:56	joegallo	(and then things blow up)
22:57	dnolen	srid: Clojure errors while initially cryptic are never wrong.
22:57	joegallo	,(seq? [1])
22:57	clojurebot	false
22:57	dnolen	only two places in you program that error can happen line 15 and line 16
22:57	joegallo	a vector is not a seq, precisely. it is seqable. (or something like that)
22:57	srid	ah
22:58	srid	so I should use (vector?) .. but I'd prefer to have a generic is-this-collection function.
22:58	dnolen	coll?
22:58	clojurebot	Reader syntax of collections has gotchas
22:58	dnolen	,(coll? ())
22:58	clojurebot	true
22:58	srid	replace seq? with vector? made the compiler happy. no warnings.
22:58	dnolen	,(coll? [])
22:58	clojurebot	true
22:59	srid	nice
23:00	alandipert	dnolen: are or-patterns and subexpr matching WIP?
23:00	dnolen	alandipert: no if those don't work, bug, example?
23:01	srid	wow, that program was correct after first run.
23:01	srid	all I had to fix was a compiler warning
23:01	dnolen	the only serious bug I want to fix is the lack of backtracking.
23:01	alandipert	dnolen: examples in readme
23:01	dnolen	alandipert: ? they don't work?
23:03	alandipert	dnolen: or rather, the or-pattern example doesn't work because of an unrelated omission (no y and z)
23:03	alandipert	and the subexpr example doesn't work for me for reasons i don't yet understand
23:03	dnolen	oops typo thx, fixing now
23:04	alandipert	"as patterns" is the other one, i managed to work things out using the test as example
23:04	dnolen	another typo
23:05	dnolen	alandipert: both fixed now
23:05	dnolen	alandipert: actually the second one isn't sorry
23:05	alandipert	i demand a refund :-)
23:08	alandipert	the expansion demonstration under 'about' also doesn't work, but maybe doesn't need to
23:11	dnolen	alandipert: changed the about expansion wording
23:12	alandipert	cool, thanks!
23:14	dnolen	alandipert: you did discover a bug tho, vector patterns of different lengths don't work, thx for the feedback.
23:14	alandipert	no prob, i hope to one day come to you with an actual patch