#clojure – 2009-11-16

2009-11-16

00:06	solussd	Just finished my highlfe implementation in clojure, if anyone's interested in some late night REPL fun: http://www.solussd.com/?p=118
00:08	tomoj	solussd: what are you using to highlight clojure code?
00:09	solussd	"SyntaxHighlighter Evolved" for wordpress. It isn't perfect, but you can easily edit the "brushes" for a language's syntax
00:10	tomoj	thanks
00:10	tomoj	just installed wordpress for the first time the other day
00:13	solussd	I I found the clojure syntax highlighter brush here: http://travis-whitton.blogspot.com/2009/06/syntaxhighlighter-for-clojure.html Turn it into a javascript file called shBrushClojure.js. You'll have to make some small modifications to the syntaxhighlighter evolved plugin to tell it where to find it.
00:13	tomoj	for now I am just going to embed gists I think
00:14	solussd	You can make the plugin changes directly from the wordpress 'admin' screens (click the modify link next to the plugin).
00:14	solussd	ok- If you do decide to install the plugin, you can do it right from wordpress's admin screens using the plugin installer.
00:18	duncanm	technomancy: i just installed slime via elpa, and i'm getting a FileNotFoundException
00:18	duncanm	technomancy: is there something i'm missing? java.io.FileNotFoundException: Could not locate swank/swank__init.class or swank/swank.clj on classpath: (NO_SOURCE_FILE:0)
00:19	defn	why is (if test then else?)
00:19	defn	not in the api documentation on clojure.org?
00:20	arbscht	duncanm: did you add (clojure-slime-config ...) to your init file as instructed?
00:21	somnium	defn: http://clojure.org/special_forms#toc2
00:22	somnium	duncanm: I installed a few hours ago, had to clean out .clojure and then it installed everything. though swank-clojure-project looks for the swank-jar in lib
00:24	defn	somnium: i know about that page -- but the special forms are completely missing from the API link
00:24	defn	which seems wrong to me, but shrug
00:24	defn	I know there's the direction to read special forms, but I don't see why you wouldn't include them in the larger list of api documentation
00:25	duncanm	arbscht: where are the instructions?
00:26	arbscht	duncanm: at the end of the clojure-install procedure
00:26	somnium	arbscht: I think that configuration step isn't necessary with the just released version
00:26	somnium	clojure-install says its deprecated now when I tried to run it
00:26	arbscht	oh?
00:26	arbscht	I see
00:26	somnium	new version just up on elpa
00:27	duncanm	somnium: that's nice
00:29	maravillas	solussd: i added a comment recently regarding that clojure brush
00:29	maravillas	need to tweak a couple of the regexes to highlight keywords properly
00:30	solussd	maravillas- cool, do you have the tweak? I'll try it now. :)
00:30	maravillas	and unfortunately the tool's getKeywords method doesn't provide a way to specify "keyword" boundaries
00:31	maravillas	{ regex: /:[a-z][A-Za-z0-9_\-]*/g, ...
00:31	maravillas	only difference is the \- in the pattern
00:36	solussd	thanks
00:36	maravillas	no problem
00:36	_ato	,:+-*/.<>=!?$%_&~^:@
00:36	clojurebot	:+-*/.<>=!?$
00:36	maravillas	heh
00:36	maravillas	well then
00:36	maravillas	guess there's more work to do
00:36	_ato	,:+-*/.<>=!?$_&~^:@
00:36	clojurebot	:+-*/.<>=!?$_&
00:36	_ato	,:+-*/.<>=!?$_&^:
00:36	clojurebot	:+-*/.<>=!?$_&
00:37	_ato	hehe
00:37	maravillas	ah yes, looks like the question mark at least is applicable to you, solussd :)
00:38	solussd	I love being able to use a question mark and exclamation points.
00:39	solussd	even better, I like using dashes in symbol names. this-is-much-more-readable thanTryingToReadStupidCamelCase
00:39	maravillas	of course they seem to be valid, but i wonder how often people use anything other than alphanumerics and dashes in keywords?
00:39	solussd	... and hitting the shift key is for suckers..
00:40	solussd	question marks are good for predicates
00:40	solussd	e.g. (if alive? (something) (something-else))
00:40	_ato	like {:alive? true, :name "Rupert"}
00:40	maravillas	sure, but i mean keywords
00:40	_ato	ha, we picked the same example
00:41	maravillas	well, i'll concede question marks, i guess
00:41	duncanm	maravillas: having ! in identifiers is common in other lisps too
00:42	duncanm	things like initialize!
00:42	maravillas	i mean only keywords
00:42	duncanm	ruby copied that into its libraries, afaik
00:42	duncanm	maravillas: why does it matter anyhow?
00:42	maravillas	it doesn't
00:42	maravillas	i'm just curious :)
00:43	duncanm	in CLOS, i think there's a style of using <Point> to notate a class
00:43	duncanm	$foo is often used to refer to fluid variables
00:43	maravillas	no, i get all that
00:43	maravillas	i mean specifically clojure keywords
00:43	maravillas	meaning, for example, :initialize!
00:44	solussd	I use :alive? in my highlife program. :)
00:44	_ato	I could see :+ :< :& etc being used in the context of something like {:operation :+}
00:45	duncanm	on a separate topic, i thought it might be cool to extend the literal syntax, so that there're literals for URLs and Paths (coming in JDK7)
00:45	maravillas	ah yes, good point
00:47	maravillas	what were you considering?
00:48	duncanm	ah, "The read table is currently not accessible to user programs." -- so no user-defined reader macros for now ;-P
00:48	duncanm	having \|/home/duncan/foo\| ought to be pretty handy
00:49	duncanm	or maybe #\|/foo/bar\|
00:49	duncanm	i work on Windows during the day, so having support for DOS-style paths would be great
00:49	duncanm	#\|C:\Program Files\|
00:50	jkkramer	anyone know if it's possible yet to get a value from a transient hash set without specifying a key? e.g. something like (nth (transient #{1 2 3}) 0) => 1 ?
00:51	chouser	[most] urls are already valid symbols
00:51	chouser	'http://foo.bar.baz/bing/bang.html
00:51	chouser	,'http://foo.bar.baz/bing/bang.html
00:51	clojurebot	http://foo.bar.baz/bing/bang.html
00:52	duncanm	chouser: i don't get your point
00:53	duncanm	maybe it's not worthwhile to add more literal syntax, (File. "/foo/bar") is not that much longer
00:53	chouser	well -- what were you going to use literal syntax for URLs to do?
00:53	_ato	jkkramer: you can't, you'll have to call persistent on it
00:53	jkkramer	:(
00:54	jkkramer	there's a commit saying TransientHashSet was implemented, but seems like only conj! and disj! work, not get or nth. those work for TransientVector
00:56	duncanm	chouser: i've been using clojure to write a lot of shell-script like programs, and esp. having to reverse my \s into /s has been kinda annoying
00:56	tomoj	what do you expect nth to do on sets?
00:56	_ato	mmm, HashSets are HashMaps underneath and TransientHashMap doesn't support nth either
00:56	duncanm	twbray: did you restart your phone? maybe you need to soft reboot it
00:57	twbray	duncanm: several times
00:57	chouser	duncanm: \ is already reversed. / is the right way to separate paths. ;-)
00:57	_ato	ah yeah nth doesn't work on a set at all
00:57	duncanm	twbray: did you jsut turn it on and off? or did you do the red button + home key thing?
00:58	jkkramer	i actually just want to get an arbitrary value from a persistent set, doesn't matter which one. i just don't want to have to specify the key
00:58	twbray	duncanm: Had to do that a couple times as part of the upgrade process. could do it again. Searching, maybe a known problem :(
00:58	jkkramer	was groping around for something like first or nth or something
00:58	duncanm	oh
00:59	duncanm	twbray: i have a G1 from T-Mobile, the update worked for me fine, sorry.
00:59	twbray	duncanm: Yeah, problem seems specific to the Ion AKA Google I/O devie
01:46	mikem	hi, what's the clojure way to execute a series of functions in order? in common-lisp the prog form is used for that
01:48	hoeck1	mikem: do
01:48	hoeck1	,(do 'foo 'bar)
01:48	clojurebot	bar
01:48	mikem	hoeck1: ah, great, thanks
01:49	hoeck1	mikem: np :)
02:51	hiredman	,(apply conj (ring-buffer 10 [] 0) (range 1000))
02:51	clojurebot	#<sandbox$ring_buffer$reify__3709 [990 991 992 993 994 995 996 997 998 999 989]>
03:58	mikem	is (assoc a (count a) "item"), where a is a vector, the best way to append an item to the end of a vector?
03:58	hiredman	use conj
03:58	mikem	by "append" i mean "return a new vector that's the same as a with item appended" of course
03:58	mikem	hiredman: ah yes, conj. Thanks
04:46	Licenser	morning everyone
04:51	AWizzArd	Moin Licenser
04:52	Licenser	How are things going in the clojure worlds?
04:52	yason_	Licenser: almost purely functional, thank you for asking
04:53	Licenser	glad to hear that :)
05:23	Licenser	I've a macro that encalpsulates a ssh session and allows to run commands and stuff on a remote host, what is the more ideomatic name for ti with-session or do-session, it kind of both makes sense to me. Do since it has side effects and with since it kind of is a with-open block in my eyes
05:24	_ato	I'd call it with-session
05:25	Licenser	thanks that was what I went with in the first place too
05:25	_ato	do-stuff tends to make me think of doto, doseq, dotimes etc. Things that change the code structure
05:27	Chousuke	generally do is used to imply that the thing is used for side-effects.
05:28	Chousuke	presumably running commands over ssh is rather side-effecty, but with-session is idiomatic for a macro that creates a context.
06:35	Drakeson	how can I interrupt a slime repl? C-c C-c does not seem to work.
06:36	_ato	C-c C-b
06:36	_ato	doesn't always work though
06:40	Licenser	sorry for the delay and thanks for the input I'll stay with with-session then
06:43	Licenser	hmm exec, scp-put, scp-get something else that might be important?
06:51	_ato	Licenser: do you support directory copies (ie the "D" scp command) with scp-put? if not, that might be something useful if you're making a general clojure ssh library
06:54	Licenser	good idea
06:54	Licenser	lets figure out how that works :P
07:19	Licenser	hrm jsch sems not tu support that :/
07:19	_ato	wait... jsch has builtin scp support? gah.. I did it myself
07:20	AWizzArd	rhickey: in the last but one example at http://www.assembla.com/wiki/show/clojure/Protocols it could also be 'AMultiProtocol' vs without 'Multi'
07:21	_ato	Licenser: http://blogs.sun.com/janp/entry/how_the_scp_protocol_works
07:26	Licenser	_ato: it has a very neat sftp support
07:26	Licenser	not scp directly
07:28	_ato	ah right
07:30	Licenser	scp looks very ugly and I didn't liked it so I used sftp, I stumbled about the same stuff you linked me to - I found it way too complicated
07:30	Licenser	then again a good scp library for clojoure would be cool I guess
07:30	Licenser	since sftp does not seem to copy directories :/
07:32	_ato	there must be a way to do it somehow as the sftp command supports it
07:33	_ato	maybe JSch just doesn't implement it :/
07:33	_ato	oh well :)
07:33	Licenser	_ato: might not be implemented in jsch,
07:33	Licenser	well or ti does but does not document it :P with couldn't be surprising
08:31	Licenser	hmm apply does not work with special forms? o.O
08:33	chouser	Licenser: I don't see how it could. what are you trying to do?
08:35	Licenser	just tried to use (apply . object method arglist)
08:36	chouser	ah, yes.
08:36	Licenser	which isn't working too well :P
08:36	chouser	"method" is not evaluated so that's just not going to work. If you know the method name at compile time, you have an excuse to write a macro.
08:37	Licenser	then again I am horrible with amcros
08:37	Licenser	method is not something to be evaluated I know the method name
08:38	Licenser	https://gist.github.com/a6e903ef4c7998d82d34 <- that is what I'm trying to do :P mostly at least
08:39	yason	Licenser: would memfn help?
08:40	chouser	that's a lot of code for a macro.
08:40	chouser	memfn hardly ever helps -- you can just use #(something) instead
08:40	Licenser	hmm chouser I think you're right
08:43	chouser	it's a macro so you can capture 'session ?
08:45	Licenser	(with-session "user" "pass" "host" 22 (do-sftp (:put "D:/test/1.txt" "/tmp") (:get "/tmp/1.txt" "D:/")))
08:45	_ato	Licenser: might be better to use a binding instead and just use a regular function for do-sftp
08:46	_ato	oh wait... you want a list
08:46	Licenser	so a) I can fetch session and b) to not have to pass nice () stuff instead of ugly '() stuff
08:46	_ato	hmm
08:47	chouser	would you find [:get "/tmp/1.txt" "D:/"] acceptable?
08:47	Licenser	hmm it kind of is not as nice as ()
08:49	chouser	ok, so I'd recommend your do-sftp macro just repackage your args -- capture 'session if you want and convert your (:put ...) to [:put ...], and then pass it all to a function to do the real work.
08:49	chouser	ah. like that!
08:49	chouser	:-)
08:49	Licenser	^^
08:49	Licenser	briliant minds think alike, and sometimes even I get teh same idea if it's obviouse enough .P
08:49	chouser	though you could probably move even more things into the fn
08:50	Licenser	nods the open and close likely
08:50	Licenser	or connect and disconnect
08:50	ohpauleez	I'm new to Clojure but not to Lisp in general. What does the hash after a symbol do?
08:50	chouser	ohpauleez: auto-gensym
08:50	Licenser	it generates a id'ed symbol for macros
08:50	ohpauleez	ahhh cool
08:50	ohpauleez	thank you both
08:52	Licenser	hey I'm glad if I once can help and don't just ask all the time :P
08:52	chouser	Licenser: note the way you've got it there, you can only pass in literal strings for your (:get ...) args.
08:53	ohpauleez	:) I understand the feeling. I remembered seeing it here (http://en.wikibooks.org/wiki/Learning_Clojure#Macros) but forgot when I was looking at your code
08:53	Licenser	^^
08:54	Licenser	I see, you're right again chouser that is bad'ish
08:54	Licenser	hmm bindings kind of broke stuff soo
08:55	_ato	Licenser: https://gist.github.com/989fbc3b6972c145d1a3
08:55	_ato	I'd do something more like that
08:55	_ato	so you can put ifs and stuff in the body
08:55	_ato	but that might not be what you're going for
08:56	Licenser	_ato: actually it pretty much is, so I wanted to remove the sftp prefixes from the stuff
09:00	Licenser	_ato: so I like how you do that with binding
09:01	_ato	yeah, means you can use functions instead of macros, and the calling code can also use functions without having to worry about passing the myserious invisible session and sftp symbols around
09:10	rhickey_	http://paste.lisp.org/display/90495
09:10	rhickey_	I think I want something like this for when defs are being explicitly provided^^
09:11	chouser	can you do extend more than once on the same type without overwriting?
09:14	Licenser	_ato: mind if I pick up from that idea?
09:15	_ato	sure go for it
09:17	Licenser	thanks
09:19	rhickey_	chouser: separate extends?, yes, only overwrite same protocol/type combo
09:19	rhickey_	big part of protocols is independent extension
09:19	chouser	ah, of course.
09:20	rhickey_	fred write P, ethel writes T, lucy extends T to P
09:20	chouser	ok, so you could mix extend-type with extend if one of the protocols needed merge but the others didn't
09:20	rhickey_	right
09:20	rhickey_	I just see a lot of impls being explicit and inline, where the map stuff is just in the way
09:21	rhickey_	also the type hint could come from the type up top and not be repeated
09:24	rhickey_	anyone want to take a crack at those?
09:27	chouser	if you don't mind waiting a couple days, I bet someone on the dev group would like to get involved.
09:28	_ato	that reminds me
09:28	_ato	rhickey_: don't suppose you've received my CA yet?
09:28	ohpauleez	Are the protocols in clojure similar to that of ObjC?
09:29	ohpauleez	nvm: http://www.assembla.com/wiki/show/clojure/Protocols
09:29	rhickey_	_ato: all people with CAs are listed on the contributors page, if you are not there I haven't gotten it (note I only check the box every week or so)
09:29	_ato	ah ok, thanks
09:30	_ato	sent it on the 6th so it'll probably be there next time you check
09:30	_ato	no worries :)
09:32	rhickey_	ohpauleez: they differ in significant ways - ObjC is duck-typed, and protocols map to class methods
09:33	rhickey_	Clojure protocol functions are not methods of the classes that extend the protocol
09:33	rhickey_	you do not indicate support of a protocol in the definition of the extending class
09:33	rhickey_	they are not duck-typed
09:33	ohpauleez	they're generic, which opens up a lot of cool possibilities
09:33	ohpauleez	I'm reading that wiki page now
09:34	ohpauleez	ps: I'm Paul, I worked on the JVM backend for PyPy
09:34	rhickey_	cool
09:34	ohpauleez	I'm migrating here, catching up, and digging in
09:35	chouser	ohpauleez: I've got some functional-flavoured kool-aid here if you'd like a sip.
09:36	ohpauleez	I tend to do more functional-esque styles in Python than OO stuff, and really enjoy Common Lisp
09:37	ohpauleez	clojure has answered many of my issues with common lisp, it's an ideal middle ground for me
10:53	the-kenny	What can cause (take 24 @my-agent) to fail with a NullPointerException when (take 23 @my-agent) works? (last works too, as does nth)
10:54	the-kenny	I think something very strange is happening here... The code worked for some hours now, but suddenly I get this NPE.
10:54	chouser	my-agent could be a lazy seq that errors when it tries to compute the 24th item
10:54	chouser	oh, 'last' works?
10:54	chouser	hmph
10:54	the-kenny	Yes
10:54	the-kenny	AS does nth
10:57	the-kenny	I use this agent as a simple queue were elements get added from a thread pool.
10:57	chouser	the stack trace doesn't point you anywhere?
10:57	the-kenny	The add-method is just a simple (if (> (count state limit) (commit-to-couchdb) (cons state json))
10:59	the-kenny	chouser: hm strage, emacs has hidden the stacktrace.. bad emacs, bad!
10:59	the-kenny	Somewhere in the regex-api
11:01	the-kenny	hm strange, I can't imagine how lazyness could cause such an error
11:03	the-kenny	hm.. I think it would help to force the evaluation of the json before I add it to the queue, right?
11:04	the-kenny	..maybe evaluation is the wrong word.
11:04	chouser	yeah, if you're reading from a file or stream into a lazy seq and then passing that off to another thread, there's definitely more timing complexity there than you probably want to deal with.
11:05	the-kenny	hm.. ok. It's just strange that this happens after hours and not before.
11:06	the-kenny	(Sorry, my english isn't very good :)
11:06	chouser	your english is fine. yeah, I can't tell you what's wrong without more details.
11:07	the-kenny	I read from a stream (http), parse this as json, pass some parts of the json to some functions to extract new data, collect this data into a new json struct, add this to the queue and push the queue to couchdb :)
11:10	AWizzArd	What foo do I need to have (= ::x (foo (deftype x []))) ==> true ?
11:10	AWizzArd	So, how do I go from a Var to a keyword, including the namespace?
11:13	chouser	you really want to process the return value of deftype, not the return value of (x ...) ?
11:13	stuartsierra	(defn foo [var] (let [m (meta var)] (symbol (name (:name m)) (name (ns-name (:ns m))))))
11:13	Licenser	geez stupid questio, how to :use :only within a ns?
11:14	stuartsierra	Licenser: (ns ... (:use [foo :only (one two three)]))
11:15	Licenser	woooh thanks stuartsierra i think I treid every other combination form m[ and (
11:15	AWizzArd	chouser: yes, I would like to know if/how I can go from a var to a Namespace-Keyword.
11:18	AWizzArd	and maybe other than (keyword (subs (str #'user) 2)) :-)
11:19	chouser	stuartsierra gave the right answer, at least until we can talk rhickey into having Vars implement Named
11:21	arohner	Is swank known to work on the deftype/defprotocol branch?
11:21	arohner	I'm getting java.lang.NoSuchMethodError: clojure.lang.RestFn.<init>(I)V
11:21	arohner	at swank.util$flet__9.<init>(util.clj:5)
11:23	the-kenny	oh strange
11:23	the-kenny	chouser: (nth 23 @my-agent) throws now too.
11:23	the-kenny	Looks like the 23th element is broken
11:24	the-kenny	Is there something like a reverse-take?
11:24	stuartsierra	arohner: I got the same error
11:25	arohner	great, mvn compile against swank downloads its own clojure.jar, rather than trying to build against my branch
11:26	chouser	(doc take-last)
11:26	clojurebot	"([n coll]); Returns a seq of the last n items in coll. Depending on the type of coll may be no better than linear time. For vectors, see also subvec."
11:26	the-kenny	Thanks :) The 23th element is definately broken.
11:29	rhickey_	extend-type and extend-class are up
11:31	stuartsierra	arohner: You can build your own Clojure JAR and install it with Maven
11:31	arohner	stuartsierra: how do I do that? Build the jar and then copy it to...?
11:32	stuartsierra	Get the Clojure sources, checkout the new branch, and run "mvn install"
11:32	stuartsierra	In the Clojure source dir
11:32	rhickey_	would extend-protocol be too confusing? when you want to provide several impls of the same protocol in one shot
11:33	rhickey_	(extend-protocol P AType (foo ...) (bar ...) BType (foo ...) (bar ...) AClass (foo ...) (bar ...) ...)
11:33	chouser	hmph. my extend-type is just now working.
11:33	chouser	I have no self-control.
11:33	rhickey_	if only I knew you were trying it
11:33	chouser	or I you
11:34	rhickey_	right
11:34	chouser	oh well, your is better
11:34	chouser	http://paste.lisp.org/display/90495#1
11:35	rhickey_	I ended up bailing on the keyword-izing, for two reasons, one, it can get confusing when you need to use the keyword and not, and two, extend-type can now work on classes or nil too
11:35	chouser	ok.
11:36	chouser	keywordizing qualified vs. unqualified symbols required surprising work
11:36	rhickey_	iirc in CLOS I was confused about when to quote clasnames
11:36	AWizzArd	Why do Vars have a .ns with some content and a .sym whose namespace is nil?
11:36	arohner	stuartsierra: my new clojure claims it is 1.1-alpha, but swank-clojure builds against clojure-1.0.0. should I rename the jar, or do something else?
11:37	rhickey_	chouser: there really isn't a good rationale for how to 'resolve' to a keyword, as the user might or might not have pulled in the name otherwise
11:37	arohner	nm, I see the dependency line in the pom
11:37	stuartsierra	arohner: change the version in the swank-clojure POM to match your new Clojure build
11:37	rhickey_	chouser: what do you think of extend-protocol idea ^^ ?
11:38	rhickey_	flips protocol/type
11:40	chouser	to let you compose in roughly the groupings that core.clj does today
11:42	rhickey_	yeah, just looking t replacing things like RT.count
11:42	rhickey_	else if(o instanceof String) return ((String) o).length();
11:42	rhickey_	becomes
11:42	rhickey_	(extend-class String Countable (cnt [s] (.length s)))
11:43	rhickey_	but with extend-protocol, a bunch of these could be grouped together:
11:43	rhickey_	(extend-protocol Countable
11:43	rhickey_	String (cnt [s] (.length s)))
11:44	chouser	I think it's probably quite reasonable. It's just that protocols vs types are still a bit slippery for me.
11:44	chouser	Having said that, I don't know that extend-protocol would make that particularly worse.
11:45	rhickey_	this seems pretty snazzy:
11:45	rhickey_	(extend-protocol Countable
11:45	rhickey_	clojure.lang.Counted (cnt [c] (.count c))
11:45	rhickey_	String (cnt [s] (.length s))
11:45	rhickey_	java.util.Map (cnt [c] (.size c))
11:45	rhickey_	nil (cnt [_] 0))
11:46	chouser	yeah, can't really argue with that
11:46	AWizzArd	Otherwise many "extend"s would be needed?
11:46	chouser	esp. since the alternative would be to say "extend foo Countable" a lot
11:47	ohpauleez	fwiw, I totally favor that (rhickey)
11:47	ohpauleez	I just ran into that this past weekend actually
11:47	rhickey_	(extend-class clojure.lang.Counted Countable (cnt [c] (.count c)))
11:47	rhickey_	(extend-class String Countable (cnt [s] (.length s)))
11:47	rhickey_	(extend-type nil Countable (cnt [_] 0))
11:47	rhickey_	(extend-class java.util.Collection Countable (cnt [c] (.size c)))
11:47	rhickey_	(extend-class java.util.Map Countable (cnt [c] (.size c)))
11:47	chouser	String #(.length %) ?
11:48	wavis	if i pass a seq into a method, and that argument is referenced once, is the head of the seq retained until the end of the method despite not being used?
11:48	rhickey_	chouser: not in these macros, at least not if they auto-type hint
11:49	rhickey_	one problem with extend-protocol would be determining when it could type hint, since it could be a mix of extended types/classes/nil
11:50	chouser	types would use keywords right?
11:54	rhickey_	chouser: yes, actually not so bad, extend-protocol probably a simple macro on top of extend-type/class
11:55	rhickey_	another problem with #(.length %) is there's no place for the fn name, which must be present as the protocol might have multiple fns
11:56	chouser	oh, right, it's actually String (count [s] (.length s))
11:56	rhickey_	yup
11:56	chouser	you were using cnt because it's not cinc quite yet, and count is something else
11:56	rhickey_	right
11:57	rhickey_	just experimenting with the perf of a protocol versus the RT methods
11:57	rhickey_	so far, faster
11:57	chouser	beautiful
11:57	rhickey_	and of course, much better in that they are extensible
11:57	chouser	I'll have to spend some time eventually figuring out what I'm doing wrong with the finger trees.
11:58	chouser	cons dispatches on the wrong arg
11:58	rhickey_	yeah, I didn't invent cons :)
11:59	chouser	hehe
11:59	chouser	finger trees want to differentiate between cons and conj
11:59	rhickey_	but things like that are just a matter of a fn on a protocol fn
11:59	chouser	maybe cons can be (defn cons [x c] (consLeft c x))
11:59	chouser	sorry!
11:59	chouser	maybe cons can be (defn cons [x c] (cons-left c x))
12:00	chouser	oh, that's what you just said.
12:01	Chousuke	I keep wanting to rewrite the reader on top of protocols and deftype all the time but other things keep me too busy to do that ;(
12:01	rhickey_	right, the protocol might not be the ultimate end-user api
12:02	chouser	gah. wth is this thing trying to use fcase.clj
12:03	rhickey_	chouser: allowing for other-than-first arg would add a lot of complexity and reduce flexibility, so I opted out
12:03	chouser	no, not at all worth it.
12:03	chouser	for simple things like cons, the solution is simple.
12:03	chouser	for complex things, multimethods are right there
12:19	arohner	stuartsierra: I fixed that java.lang.NoSuchMethodError: clojure.lang.RestFn.<init>(I)V by rebuilding clojure-contrib
12:19	arohner	I also had to clean clojure-contrib before it would build happily
12:20	hiredman	that exception, as far as I can tell, always means you need to rebuild contrib
12:20	hiredman	I don't recall ever seeing it any other time
12:21	arohner	hiredman: where were you an hour ago? :-)
12:28	rhickey_	extend-protocol is up
12:36	AWizzArd	thx
12:39	wavis	how do I process a large coll within a method without retaining the head?
12:39	stuartsierra	rhickey_: really, protocol methods are faster than RT? Awesome. I assumed they would be slightly slower.
12:40	stuartsierra	So this means any new type can implement conj/count/first/rest/..., with the same performance as built-in types?
12:41	arohner	,(doc dorun)
12:41	clojurebot	"([coll] [n coll]); When lazy sequences are produced via functions that have side effects, any effects other than those needed to produce the first element in the seq do not occur until the seq is consumed. dorun can be used to force any effects. Walks through the successive nexts of the seq, does not retain the head and returns nil."
12:41	wavis	arohner: doesn't work. the head of the coll is retained until the end of the method
12:43	wavis	i made it work by creating a once-accessible IDeref that sets its value to null after the first access. but that's messy.
12:43	stuartsierra	wavis: you can iterate over a large collection safely with loop/recur
12:44	hiredman	or iterate?
12:45	wavis	stuartsierra: I haven't tried that, but isn't it essentially the same solution as dorun? I'll open a loop in the mehtod, but the head of the coll will stick around until the end. maybe I need to do something other than use large collections.
12:45	hiredman	wavis: are you sure dorun is hanging on to the head?
12:46	wavis	dorun isn't, but because i pass the collection into the method as an arg, the arg is.
12:46	arohner	~def dorun
12:46	rhickey_	stuartsierra: yes, that's the idea
12:46	arohner	looks like the head is only present in the first iteration
12:47	rhickey_	once count/first/rest become protocols
12:47	hiredman	wavis: args are cleared on tail calls
12:47	stuartsierra	rhickey_: awesome
12:47	rhickey_	the RT methods a) still have to be wrapped in Clojure fns
12:47	rhickey_	b) have manual dispatch using conditionals
12:48	rhickey_	a protocol implementation will get wired into a call site, and even sites that change do caching
12:48	rhickey_	so most of the time there is no lookup
12:49	stuartsierra	Ah, yes. That's how polymorphism is supposed to work. :)
12:50	wavis	hiredman: right. so i need to compose two methods, one which processes the coll, and hands off to the second step in the process where the head is not retained. OK gracias
12:51	rhickey_	(defprotocol S (s [x]))
12:51	rhickey_	(extend-class clojure.lang.ISeq S (s [x] (.seq x)))
12:51	rhickey_	(def #^clojure.lang.ISeq sq (seq [1 2 3]))
12:51	rhickey_	(time (dotimes [_ 100000000] (seq sq)))
12:52	rhickey_	user=> "Elapsed time: 916.738 msecs"
12:52	rhickey_	(time (dotimes [_ 100000000] (s sq)))
12:52	rhickey_	user=> "Elapsed time: 619.931 msecs"
13:44	pjstadig	~suddenly
13:44	clojurebot	CLABANGO!
13:44	pjstadig	hehe
13:44	pjstadig	still works
13:44	danlarkin	demons have been summoned
13:45	danlarkin	or should I say daemons have
13:45	danlarkin	ha!
13:50	polypus	is there a map function which preserves the data-structure type?
13:51	technomancy	polypus: I usually use reduce for that
13:51	polypus	(map #(str % "!") ['a 'b 'c]) -> [a! b! c!] not a seq
13:52	polypus	ok thx, just checking
13:58	djpowell	wrap it in (into (empty s)
14:08	danlarkin	what's the best way to check if a symbol is bound to a byte array?
14:09	danlarkin	(= (type (make-byte-array) (type v)) is lame
14:09	danlarkin	oops, mismatched parens there, but you get the idea
14:11	AWizzArd	rhickey: can one extend Arrays of "long" with a protocol?
14:11	AWizzArd	Or ArrayList of Foos?
14:20	mrSpec	Hello
14:24	ohpauleez	is there an easy way to do something like python's "in" as a predicate? ex: if 4 in [2, 4, 1, 3, 5, 6, etc] returns true if 4 is in the collection
14:25	ohpauleez	I was looking through the cookbook and special forms, but I'm not coming up with anything
14:25	piccolino	(contains? [2 4 1 3] 4)
14:25	ohpauleez	also looked in seq-utils in contrib
14:25	ohpauleez	ahh, thank you
14:25	hiredman	be sure to read the docstring for contains?
14:26	rhickey_	(some #{4} '[2, 4, 1, 3, 5, 6, etc] )
14:26	rhickey_	,(some #{4} '[2, 4, 1, 3, 5, 6, etc] )
14:26	clojurebot	4
14:26	ohpauleez	Ah, that's awesome too
14:27	ohpauleez	thanks hiredman
14:27	rhickey_	not only awesome, but correct, the contains? thing isn't
14:27	rhickey_	,(contains? [2 4 1 3] 4)
14:27	clojurebot	false
14:28	piccolino	Yeah. That's what I get for guessing a function name.
14:28	rhickey_	contains? tests associative things for their keys, which for arrays is their indices
14:29	ohpauleez	I just read the doc and realized that
14:29	rhickey_	Java's Collection.contains is available, however
14:29	rhickey_	,(.contains [2 4 1 3] 4)
14:29	clojurebot	true
14:29	hiredman	reading docs is good
14:31	ohpauleez	yeah I just couldn't find the common idiomatic approach, thanks guys
14:44	rhickey	AWizzArd: arrays of long, yes, if a bit icky (Class/forName "[J")
14:44	rhickey	ArrayList of Foos, no, generic types are not reified
14:45	rhickey	but ArrayList, yes
15:17	krumholt_	hi i am reading on the clojure.org page about vars and the global environment. i am not a native english speaker so maybe i don't get the meaning but what does this mean? "Bindings created with binding can be assigned to, which provides a means for nested contexts to communicate with code before it the call stack." Is it possible there is a word missing?
15:18	kanak	krumholt_: "before _it_ in the call stack" maybe?
15:19	hiredman	on
15:19	chouser	right. "before it on the call stack"
15:20	chouser	it's a scary little feature, fortunately very rarely used.
15:20	krumholt_	ok
15:20	chouser	in fact, I think I've only seen it used in Compiler.java
15:20	kanak	isn't binding somewhat like special variables?
15:21	krumholt_	i used binding to get a thread local version of a global variable. just wanted to read up on it and didn't understand the sentence
15:22	chouser	getting a thread local of a global var is good and common
15:22	dnolen	kanak: yes
15:22	krumholt_	ok
15:22	krumholt_	good thanks :)
15:23	chouser	changing it on a deeper part of the call stack in order to communicate up the call stack is unusual, too-clever, and a bit scary.
15:24	rhickey	I never got around to wrapping that in a Sow/Reap thing like Mathematica has
15:25	rhickey	http://reference.wolfram.com/mathematica/tutorial/CollectingExpressionsDuringEvaluation.html
15:25	chouser	does that make it less scary? reaping doesn't sound less scary.
15:26	rhickey	heh
15:28	lisppaste8	Chouser pasted "using binding to pass extra return values" at http://paste.lisp.org/display/90515
15:29	chouser	hm! possibly less scary.
15:31	kanak	what would the disadvantages of having a CL-style multiple return values be?
15:32	tomoj	java?
15:32	chouser	kanak: clojure fn calls could no longer be simply java method calls (and vice-versa)
15:33	chouser	kanak: though someone did build a CL-style multiple return value lib on top of thread-local bindings
15:33	chouser	ages ago
15:33	rhickey	early Clojure prototypes had it
15:34	notallama	how do you get a specific branch with git? (i'm trying to download new)
15:34	kanak	chouser: thanks for the reply.
15:35	chouser	http://paste.lisp.org/display/68919 -- jochu, 1 year, 3 weeks ago
15:35	rhickey	but yes, you can't manipulate the real stack using JVM bytecode the way you'd want, so you end up with thread locals, and making it transparent to use either one or more than one of the returns (the key CL feature vs just returning tuples) makes all calls less efficient
15:35	rhickey	so it's out
15:35	arohner	notallama: git checkout <branchname>
15:36	chouser	huh. I bet that code all still works. not too shabby.
15:37	chouser	oh, nope. old 'when' form
15:37	chouser	bah, nm. that didn't change. :-P
15:37	notallama	arohner: i get "error: pathspec 'new' did not match any file(s) known to git."
15:38	arohner	notallama: git branch -a to see the list of branches
15:38	arohner	you'll probably want git branch -t origin/new
15:40	dakrone	is there a contrib function similar to duck stream's read-lines, but for reading a # of bytes?
15:40	arohner	notallama: that sets up a local branch to track the remote branch, so you can stay up to date with it
15:42	notallama	arohner: i have no idea what that means. got it working well enough for my needs, though. thanks!
15:43	arohner	notallama: this describes tracking in more detail, if you're interested
15:43	arohner	http://book.git-scm.com/4_tracking_branches.html
15:43	hiredman	(comp first (juxt first #(.read (second %) (first %)) (juxt (comp (partial make-array Byte/TYPE) first) second) list)
15:43	hiredman	or something
15:44	hiredman	dakrone: I don't know, but if you are dealing with an inputstream it is pretty trivial to use the .read method directly
15:45	dnolen	people who are up the deftype, defprotocol work - is declaring a protocol the same as writing and loading a Java interface except you can do it dynamically at runtime?
15:46	dakrone	hiredman: doesn't read-lines returns it as a lazy-seq? I was trying to do a pmap over a giant file in 8192-byte sized chucks, would .read work for that?
15:46	dakrone	without loading the entire thing into memory
15:46	hiredman	dakrone: yes
15:46	hiredman	it would be slightly more complicated
15:46	chouser	dnolen: there are several important differences, but that'll do as a sort of rough-cut of the general category of functionaly protocol provides.
15:47	dakrone	hiredman: okay, I'll try using .read directly
15:47	dakrone	thanks
15:47	hiredman	you would use repeatedly
15:47	chouser	rhickey: is there a story now for consuming protocol-related things in Java?
15:47	hiredman	and a thunk that calls .read
15:49	dnolen	chouser: k good to know.
15:49	rhickey	chouser: same story, just tell them to implement an interface, on the Clojure side (extend ThatInterface TheProtocol)
15:50	rhickey	or now, (extend-class TheInterface ...)
15:50	chouser	I meant the other way around -- if IPersistentCollection is just a protocol, how does Java use one?
15:50	rhickey	the extend-* are definitely handy
15:51	rhickey	chouser: it always required an interface for Java, and always will. So, there will be matching interfaces if only for that purpose
15:51	rhickey	even with :on that was still the case
15:52	rhickey	but, and this is true today as well, any interface for which extend is already written is an ok way to connect to the protocol
15:52	rhickey	e.g. things that are Java collections and Iterables will work, because the protocols will be extended to them anyway
15:53	chouser	hm, I think I get it. With :on I was imagining there'd often be a protocol that with just the same methods as the interface.
15:53	chouser	but there's no point in that, you can just extend the interface instead of the protocol
15:53	rhickey	chouser: that may still be, but still 2 things
15:54	rhickey	a protocol isn't a thing in Java type terms, so not something you could derive from
15:54	chouser	right, I get that.
15:54	rhickey	I have one more idea for :on that might yield some additional advantage to having it, at some implementation complexity cost TBD
15:55	dnolen	rhickey: so why would you use extend-protocol? (sorry still trying to understand, just saw that you added that)
15:55	spuz	What's the correct syntax for the load-file function? When I try (load-file "sub/dir/file.clj") I get "No such namespace: sub/dir"
15:56	hiredman	,(doc load-file)
15:56	clojurebot	"([name]); Sequentially read and evaluate the set of forms contained in the file."
15:56	hiredman	:\|
15:56	hiredman	spuz: needs a file://
15:56	rhickey	when you want to write the implementation of a single protocol for several types all at once, reduces repetition
15:56	rhickey	dnolen: ^^
15:56	hiredman	spuz: I think
15:56	chouser	dnolen: it just lets you group your implementation fns differently: http://clojure-log.n01se.net/date/2009-11-16.html#11:42c
15:56	hiredman	actually
15:57	spuz	hiredman: really? Hmm I'm sure I've used it with the direct file name in the past. Maybe it has to be on the class path?
15:57	chouser	I've used load-file with a plain path string not on the classpath
15:58	lisppaste8	rhickey pasted "doc extend-protocol" at http://paste.lisp.org/display/90517
15:58	chouser	spuz: you're suring there's nothing wrong in the file itself, some reference to "sub/dir"?
15:58	dnolen	rhickey: so that instead of multiple deftype with an interface plus method implementations?
15:58	dnolen	I suppose I'm confused by the fact you can provide method implementations in deftype and other ways.
15:58	chouser	yes, try to ignore deftype method definitions
15:59	spuz	chouser: yes, but perhaps my cwd is not the same as the path I launched clojure from...
15:59	dnolen	chouser: as in that's not something that should generally be done?
15:59	chouser	dnolen: they're just there to confuse you (and to solve interop issues)
15:59	rhickey	dnolen: methods and protocol functions are completely different things, it's easiest to learn about the latter if you ignore the former
15:59	dnolen	chouser: it definitely worked :)
15:59	spuz	chouser: eh, actually, it's working now, no idea why it wasn't earlier...
16:01	dnolen	rhickey: so deftype with fields + protocols is the better way to think about things.
16:01	rhickey	dnolen: that's the pure protocol way, yes
16:01	AWizzArd	Nice video of Guy Steele, talking about functional programming and parallelism: http://vimeo.com/6624203
16:02	AWizzArd	fits well to rhickeys talk about time management, which was recently uploaded
16:02	hiredman	gah, I still don't understand how github can be so broken with firefox
16:02	dnolen	rhickey: chouser: thx much for the clarifications. I think I'm beginning to understand.
16:07	fyuryu	anyone got the clojur-maven-plugin + clojure:swank goal working on Windows?
16:51	qed	http://pastie.org/private/cxw8cedwaate4y4lmj7y8a
16:52	qed	what's wrong with this picture?
16:54	hiredman	no docstring?
16:54	qed	hehe, is there anything wrong with the general form of it?
16:54	qed	(step n) returns n/2 if its even , and 3n+1 if odd
16:55	lenst	it never halts
16:55	qed	im trying to make a vector starting at n = let's say 100, and have it conj onto the vector for each step
16:55	hiredman	qed: I imagine it loops forever because you never change n
16:55	qed	oh rigt
16:55	qed	right*
16:57	_mst	and even then you've only gone from "will never halt" to "might never halt" ;)
16:57	ohpauleez	haha
16:57	qed	lol
16:57	hiredman	_mst: :)
16:57	qed	nevermind
17:20	johnmn3	hello
17:21	johnmn3	I was reading the tutorial at riddel.us. I was wondering if there are tutorials for using the new branch
17:22	duncanm	la la la
17:23	Chousuke	johnmn3: I don't think there are tutorials but the assembla wiki pages contain the current documentation :P
17:24	johnmn3	yea, I've been checking that out.
17:24	johnmn3	I'm sure people are running the new branch on emacs.. are there any caveats?
17:24	johnmn3	or is it as simple as replacing the jar?
17:26	arohner_	johnmn3: I had to rebuild clojure-contrib and swank to get things to work on the new branch
17:26	Chousuke	you may need to recompile contrib/swank/whatever
17:27	johnmn3	hmm. ok. There's a new build of contrib on the build site.
17:27	johnmn3	which, I believe was said to be compatible with new
17:34	stuartsierra	johnmn3: you still have to rebuild contrib/swank with the new branch of clojure for it all to work, I think
17:35	KirinDave	Hey folks. is there a concurrency guide for clojure?
17:35	KirinDave	Like if I wanted to segment a task (say fetching urls) into groups and threading them out
17:35	KirinDave	is that just a job for agents?
17:36	johnmn3	stuartsierra: ok. Thanks.
17:36	the-kenny	KirinDave: I've managed to do this with a ThreadPool from java for the processing and an agent for collecting the results.
17:36	KirinDave	the-kenny: Yeah I could use the underlying java threading primitives
17:36	hiredman	,(doc pmap)
17:36	clojurebot	"([f coll] [f coll & colls]); Like map, except f is applied in parallel. Semi-lazy in that the parallel computation stays ahead of the consumption, but doesn't realize the entire result unless required. Only useful for computationally intensive functions where the time of f dominates the coordination overhead."
17:36	AWizzArd	Contrib json module says: (json-str {200 [1 2 3], 401 [0 0 8]}) ==> "{\"200\":[1,2,3],\"401\":[0,0,8]}" - is this really allowed? Aren't {} objects in JS and need named fields as their keys?
17:37	hiredman	AWizzArd: looks valid to me
17:37	KirinDave	hiredman: How do I know how "wide" that operation is going to be? Do I have any way of knowing or controlling that?
17:38	AWizzArd	hiredman: oki
17:38	KirinDave	Like I could imagine for a width N operation saying (partition N (map agent urls-to-fetch))
17:38	KirinDave	and then sending to all of them.
17:38	KirinDave	But then I wouldn't really know how many underlying threads are in the threadpool that agent purports to use.
17:38	hiredman	:(
17:39	hiredman	KirinDave: depends
17:40	KirinDave	hiredman: Please do go on :)
17:40	AWizzArd	hiredman: yes, you are right, the rfc says it's ok
17:40	hiredman	if you send via send the agent's action is run on a threadpool bounded by 1 or 2 plus the number of cores
17:40	KirinDave	Oh so it is based of the number of cores?
17:40	hiredman	if you use send-off the threadpool is unbounded
17:40	KirinDave	So I can assume the number is going to be reasonable?
17:40	hiredman	KirinDave: just use pmap
17:41	hiredman	seriously
17:41	KirinDave	So pmap and then force?
17:41	hiredman	or not, as you please
17:41	KirinDave	Well, if the job is fetching URLs :)
17:42	KirinDave	I've gotta confess this is so murky to me. I've been spoiled by erlang's fire-and-forget concurrency.
17:42	technomancy	pmap will attempt to stay ahead of the consumer IIRC
17:42	hiredman	KirinDave: pmap is fire and forget
17:42	KirinDave	technomancy: So it claims in the documentation.
17:42	KirinDave	hiredman: That's cool and I didn't know about pmap, so thank you.
17:43	KirinDave	hiredman: But if I wanted to say, ensure at most 4 simultaneous connections?
17:43	hiredman	ah
17:43	hiredman	well
17:43	technomancy	unslot your extra cores from the die
17:43	KirinDave	Lol
17:43	hiredman	you can use agents
17:44	hiredman	I guess you could use them in the manner you suggested
17:44	KirinDave	Is it frowned upon?
17:44	hiredman	I am more partial to something like (cycle (take 4 (repeatedly #(agent nil))))
17:44	technomancy	KirinDave: you could make a version of pmap that accepts a concurrency-count as an argument; it's a simple enough function to just copy
17:44	KirinDave	I've seen examples where people just go (map agent (range 5))
17:45	KirinDave	To do stuff like that.
17:45	hiredman	well
17:45	hiredman	you know, why not make an agetn per url
17:45	hiredman	agent
17:45	hiredman	(like your example did)
17:45	KirinDave	(take 4 ...), wait on them
17:45	KirinDave	and then continue?
17:45	hiredman	I mean, agents are already backed by threadpools
17:46	hiredman	KirinDave: nah, do it the wya you were doing it
17:46	KirinDave	(map agent (partition width urls-to-fetch))
17:46	KirinDave	Okay
17:47	KirinDave	Would it be unreasonable to desire that you could link agents to a specific threadpool
17:47	KirinDave	If you wanted to make a more dynamic behavior change in flight?
17:49	hiredman	(map fetch (map agent urls))
17:50	AWizzArd	á propos map.. (dotimes [i 100000000] (inc %)) takes one second to run on my system. (def x (map #(do (dotimes [i 100000000] (inc %)) %) (range 10))) immediately returns, as expected. But why does (time (nth x 2)) take 10 seconds, and not only 3? And when I then want to print x in the repl it returns immediately. I would thought that only then all 10 runs be done.
17:50	AWizzArd	"would thought" ==> "would think"
17:52	AWizzArd	When I replace map with pmap then it also immediately returns, but i see how my both cores are burning for around 5 seconds. Seems that pmap very much stays ahead.
17:52	AWizzArd	strange
17:53	hiredman	(dotimes [i 100000000] (inc %)) doesn't actually run
17:53	AWizzArd	yes, it was i instead of %
17:53	AWizzArd	but in the map i replaced the i with the % so that i can use the #() reader macro vs. (fn [_] ...)
18:00	AWizzArd	hiredman: can you reproduce that? I don't understand it so far :-)
18:03	krumholt_	,(let [+ -] (+ 1 1))
18:03	clojurebot	0
18:03	krumholt_	,(binding [+ -] (+ 1 1))
18:03	clojurebot	2
18:03	hiredman	krumholt_: + is inlined
18:03	krumholt_	can someone explain the difference?
18:04	hiredman	AWizzArd: try (def x (map #(do (dotimes [i 100000000] (inc %)) (println %) %) (range 10))) with nth
18:05	krumholt_	hiredman, so the compiler optimizes the call to + ? in binding but not in let ?
18:05	Chousuke	krumholt_: the thing is, in the binding form the + refers to the var #'+, but in the let form it's just a local
18:06	krumholt_	ah ok thanks
18:06	Chousuke	krumholt_: and because the compiler inlines + for two arguments, the binding fails to work.
18:06	krumholt_	i get it thanks a lot
18:06	Chousuke	,(binding [+ -] (+ 1 2 3)); no inlining
18:06	clojurebot	-4
18:06	krumholt_	bad compiler :)
18:07	Chousuke	the clojure compiler has next to no smarts
18:07	Chousuke	well, besides "big" optimisations I guess.
18:07	hiredman	,(nth (map pr (range 10)) 2)
18:07	clojurebot	0123456789
18:07	Chousuke	but any details are left to the JVM.
18:07	hiredman	that is rather tourbling
18:08	hiredman	troubling
18:08	duncanm	hiredman: yeah, that's no good
18:08	Chousuke	I think that's because range is chunked
18:08	AWizzArd	hiredman: yes, it printed all
18:09	duncanm	hiredman: on my machine, running Clojure 1.0, i get user> (nth (map pr (range 10)) 2)
18:09	hiredman	I see
18:09	duncanm	012nil
18:09	hiredman	duncanm: yes
18:09	Chousuke	,(nth (map pr (range 64)) 2)
18:09	clojurebot	012345678910111213141516171819202122232425262728293031
18:09	Chousuke	note, first 32 items only :)
18:09	Chousuke	(the size of the chunk)
18:10	hiredman	Chousuke: still troubling for people expect map to be lazy
18:10	hiredman	expecting
18:10	AWizzArd	i didn't know that
18:10	Chousuke	moral of the story: laziness is not a guarantee, and you should keep it away from side-effects
18:10	AWizzArd	i thought that map is indeed very lazy
18:10	hiredman	Chousuke: what?
18:11	Chousuke	AWizzArd: it depends on the data structure.
18:11	hiredman	more like someone changed the semantics of map
18:11	Chousuke	hiredman: it hasn't changed.
18:11	hiredman	Chousuke: not directly
18:11	Chousuke	hiredman: there was never a guarantee that it only evaluates things one-by-one :)
18:11	hiredman	Chousuke: bull
18:12	Chousuke	hiredman: where does it say that in the docs?
18:12	Chousuke	it only specifies a lazy seq.
18:12	AWizzArd	i would think that i tried this in the past and did not see this behaviour
18:12	Chousuke	AWizzArd: it's an optimisation
18:12	Chousuke	AWizzArd: for example, it makes no sense to map things one-by-one over a vector.
18:12	hiredman	Chousuke: no it isn't
18:12	Chousuke	yes it is.
18:12	hiredman	it changes the semantics of the code
18:13	AWizzArd	but is this new behaviour?
18:13	Chousuke	hiredman: no it doesn't, if it's purely functional :)
18:13	hiredman	Chousuke: so?
18:13	Chousuke	AWizzArd: it's existed since chunked sequences.
18:13	hiredman	clojure has never been purely functional
18:13	Chousuke	hiredman: you're not supposed to use lazy sequences for side-effects :P
18:13	hiredman	it means you might end up running more computations then you want to
18:14	hiredman	even if you are purely functional
18:14	AWizzArd	i think lazyness is the optimization... not doing stuff
18:14	Chousuke	which is an optimisation in some cases.
18:14	Chousuke	for example. reducing or mapping over a vector is much faster thanks to chunking.
18:14	AWizzArd	if my f in (map f coll) is expensive, say, 20 minutes runtime, then I am happy if I only need to calculate 3 and not 19
18:14	hiredman	(nth (map some-calculation (range 10)) i)
18:15	hiredman	where some-calculation is a pure function and i is a number determined somehow
18:15	Chousuke	yes.
18:15	hiredman	suddenly your code is slower because it is doing more
18:15	Chousuke	it'll calculate all 10
18:15	arohner_	hiredman: it could be worse. In scheme, they don't even specify that map evaluates in order
18:15	arohner_	:-)
18:15	Chousuke	that very probably won't matter.
18:15	AWizzArd	would be nice to have a lmap, which really is lazy
18:16	michaeljaaka	Hi
18:16	AWizzArd	and plmap
18:16	michaeljaaka	I'm tring to run my app
18:16	michaeljaaka	I have some functions in clj
18:16	Chousuke	,(nth (map pr (seq (range 10))) 2)
18:16	arohner_	AWizzArd: you mean, guarantees one-at-a-time evaluation?
18:16	clojurebot	0123456789
18:16	Chousuke	hmm
18:16	michaeljaaka	and I want to call one of them to start
18:16	AWizzArd	arohner_: yes
18:16	michaeljaaka	java -cp MyClojureProject.jar:lib/clojure-1.0.0.jar:lib/clojure-contrib-1.0.0.jar:lib/DistributedCommunication.jar:lib/JRuceCommons.jar clojure.main -e "(require 'com.yourcompany.receiver)(com.yourcompany.receiver/runr)"
18:16	michaeljaaka	Error occurred during initialization of VM
18:16	michaeljaaka	java.lang.Error: Properties init: Could not determine current working directory.
18:16	michaeljaaka	at java.lang.System.initProperties(Native Method)
18:16	michaeljaaka	at java.lang.System.initializeSystemClass(System.java:1087)
18:16	arohner_	AWizzArd: how do you tell the difference?
18:16	AWizzArd	for plmap it would be okay to stay ahead of the consumer, but it does not necessarily mean to be eager
18:16	Chousuke	hiredman: but seriously, this thing is an optimisation. you can ask rhickey :)
18:16	michaeljaaka	what is wrong with that?
18:17	hiredman	Chousuke: I understand that chunked seqs are supposed to be an optimization
18:17	hiredman	michaeljaaka: what is wrong is a failure to use a pastebin
18:17	AWizzArd	arohner_: the difference is that for a f with a runtime of 20 minutes (second (map f (range 19))) would not run 40 minutes, but over 6 hours
18:17	hiredman	Chousuke: but this completely alters the behaviour of map
18:18	michaeljaaka	pastebin?
18:18	Chousuke	hiredman: behaviour which was never specified :P
18:18	Chousuke	hiredman: so it's fine to alter.
18:18	hiredman	~google pastebin
18:18	clojurebot	First, out of 151000 results is:
18:18	clojurebot	pastebin - collaborative debugging tool
18:18	clojurebot	http://pastebin.com/
18:18	michaeljaaka	ok
18:18	hiredman	Chousuke: it's not fine
18:18	Chousuke	AWizzArd: in weird cases like those you'd ensure the seq is not chunked.
18:19	hiredman	when people have programs that rely on the old behaviour that break
18:19	Chousuke	hiredman: sure it is. at least in this case.
18:19	Chousuke	hiredman: what happens is that some silly programs may become a bit slower.
18:19	Chousuke	hiredman: while most get a lot faster.
18:19	hiredman	…
18:19	_ato	michaeljaaka: might be a filesystem permissions problem. what directory are you running it from?
18:19	michaeljaaka	http://pastebin.com/m656eaf9f
18:20	michaeljaaka	I'm running it from my home directory
18:20	Chousuke	hiredman: the thing is, supporting the old behaviour would require not having chunked seqs.
18:20	AWizzArd	i think a new map construct could be used to work as map currently does, while the old map would automatically ensure that its colls are not chunks then
18:20	Chousuke	hiredman: that's not an okay tradeoff :)
18:20	_ato	hmm odd then
18:20	_ato	michaeljaaka: does the clojure repl work if you run it without all the other jars?
18:20	hiredman	Chousuke: not for people who relied on the lazy behaviour of map
18:21	michaeljaaka	yes
18:21	michaeljaaka	it works too
18:21	hiredman	map is no longer lazy then
18:21	Chousuke	it is
18:21	Chousuke	just less lazy than it was before.
18:21	Chousuke	for SOME seqs.
18:21	_ato	michaeljaaka: I guess one of those jars is messing up java's system properties then
18:21	michaeljaaka	because the first jar has meta-info ith set classpath to all others jars in libs
18:21	AWizzArd	,(chunked-seq? (range 10))
18:21	clojurebot	false
18:21	Chousuke	hmm. that should be true.
18:21	hiredman	the whole move to the lazier branch was to avoid this kind of non-lazy behaviour
18:22	Chousuke	(nth (map pr (iterate inc 1)) 2)
18:22	Chousuke	,(nth (map pr (iterate inc 1)) 2)
18:22	clojurebot	123
18:22	Chousuke	hiredman: but sometimes laziness is less performant.
18:22	michaeljaaka	hmmm I will try to make dummy example project to see if it works
18:23	AWizzArd	,(chunked-seq? (iterate inc 10))
18:23	clojurebot	false
18:23	hiredman	Chousuke: sure, but this negates http://clojure.org/lazier
18:23	Chousuke	hiredman: negates? how?
18:23	notallama	so i have 4 functions that work on fns, and they work fine. i get all sorts of errors if i instead define a protocall with those 4 functions, and extend IFn with the same bodies. am i doing it wrong, or is it broken? http://paste.lisp.org/display/90530
18:24	Chousuke	hiredman: full laziness is still possible.
18:24	Chousuke	hiredman: but for some seqs, map is not fully lazy because it makes no sense.
18:24	hiredman	Chousuke: why doesn't it make sense?
18:25	AWizzArd	i also have to admit that i find this unexpected...
18:25	Chousuke	hiredman: either because the data is already there. or the overhead of laziness is too high.
18:26	hiredman	Chousuke: sure, the data is already there for the range, but not the map
18:26	michaeljaaka	hmmm, It works for dummy project ;(
18:26	Chousuke	hiredman: yes, but that really doesn't matter.
18:26	hiredman	it does!
18:27	AWizzArd	Chousuke: so, how do i make (first (map #(pr % ",") (range 100))) really lazy?
18:27	Chousuke	hiredman: if your operation is so expensive you can't afford to computer it ahead by at most 32 items, you should use pmap or some other model altogether :P
18:27	Chousuke	compute*
18:27	Chousuke	at most 31, even.
18:28	AWizzArd	Chousuke: but even pmap will let my 32 core machine burn on all cores for 20 minutes then
18:28	AWizzArd	i just wanted the first 2 elements, and only knew this at runtime
18:28	Chousuke	an easy way to unchunk a seq is to concat an empty list to it
18:28	hiredman	…
18:29	AWizzArd	this won't work for (range 10) tho, as this isn't even a chunked seq..
18:29	Chousuke	but seriously, any concerns you are having are purely theoretical
18:29	hiredman	,(nth (rest (concat () (map pr (range 10)))) 2)
18:29	clojurebot	0123456789
18:29	hiredman	:\|
18:29	michaeljaaka	_ato: I know what it was
18:29	AWizzArd	so, how can this be really lazy?
18:30	hiredman	Chousuke: any assurances you've given have been purely theoretical
18:30	Chousuke	hiredman: has anyone actually been bit by this?
18:30	michaeljaaka	_ato: I'm using enclojure, I rebuilded the project and the Terminal has just lost the dist directory because it was deleted by netbeans
18:30	Chousuke	hiredman: this has been the default behaviour for who knows for how long already :P
18:30	hiredman	Chousuke: AWizzArd just was
18:30	AWizzArd	perhaps some more people were hit and just didn't find out yet
18:30	michaeljaaka	_ato: the new one was created but terminal had still old reference
18:30	_ato	michaeljaaka: ah right. :)
18:31	michaeljaaka	_ato: solution, exit and enter again
18:31	hiredman	it means I have to reexamine everything
18:31	AWizzArd	Chousuke: I didn't notice it for quite a long time and was totally convinced that it will really be lazy
18:31	michaeljaaka	_ato: thanks anyway!
18:31	AWizzArd	with pmap okay, this will consume a bit more
18:31	AWizzArd	but map is fully lazy - i thought
18:31	hiredman	clojurebot's input fuzzer takes a long time to run, perhaps somewhere something is returning a lazy seq
18:31	hiredman	er
18:31	hiredman	a chunked seq
18:32	hiredman	so it is doing more work than it needs to
18:32	AWizzArd	would be great if i could count on the lazyness, even if that reduces the runtime speed in some cases
18:33	AWizzArd	and, if there is a way to make map guaranteed work lazy, then map could ensure that it will always work like this, and we simply get a new-map
18:33	AWizzArd	(def new-map map) ... (defn map .. really lazy ...)
18:34	Chousuke	either way, I don't see this as a big enough problem to be worth fixing :P
18:35	AWizzArd	so, do you have then a way how to make map work guaranteed lazy?
18:35	Chousuke	I thought the concat trick worked but hmm
18:35	dreish	Just use the pre-chunks implementation.
18:36	AWizzArd	,(set-mode map :pre-chunked)
18:36	clojurebot	java.lang.Exception: Unable to resolve symbol: set-mode in this context
18:36	Chousuke	,(nth (map pr [1 2 3 4]) 2)
18:36	clojurebot	1234
18:36	Chousuke	,(nth (map pr (concat () [1 2 3 4])) 2)
18:36	clojurebot	1234
18:36	Chousuke	hmm. :/
18:37	AWizzArd	so, map is mostly eager, but can in some cases be lazy
18:37	Chousuke	it's not mostly eager
18:37	Chousuke	it's mostly lazy, but can in some cases be eager :)
18:38	hiredman	and you will never know when it will do which
18:38	Chousuke	the eager cases so far are vectors, maps, sets and ranges
18:38	Chousuke	because those are "eager" data structures. except for range I guess.
18:38	hiredman	Chousuke: but the result is not eager!
18:38	hiredman	or should not be
18:38	AWizzArd	,(first (filter (comp #(= % 3) pr) (range 100)))
18:38	clojurebot	0123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899
18:39	AWizzArd	sigh
18:39	hiredman	I might know all the values in a vector
18:39	hiredman	but that doesn't mean I want them eagerly mapped!
18:39	Chousuke	hiredman: but in the overwhelming majority of cases that doesn't matter :/
18:39	Chousuke	it's not fully eager either. only 32 items at once.
18:39	_ato	AWizzArd: err... that pr returns nil causing the filter to run through the whole range
18:40	AWizzArd	,(first (filter #(do (pr %) (= % 3)) (range 100)))
18:40	clojurebot	3
18:40	clojurebot	012345678910111213141516171819202122232425262728293031
18:41	AWizzArd	Chousuke: so what would be bad about having it fully lazy then?
18:41	AWizzArd	if people care about performance then there is always pmap
18:41	Chousuke	AWizzArd: it would not be as performant due to the overhead.
18:42	dreish	pmap isn't generally faster.
18:42	Chousuke	AWizzArd: pmap is even less performant.
18:42	AWizzArd	if f is not something like + then pmap will be more performant
18:42	dreish	AWizzArd: Really, just git checkout 14316ae2110a or whatever, look at the source of map at the time, call it map1, and go on with your life.
18:42	dreish	It's really not that big a deal.
18:42	AWizzArd	but if f is so cheap, why then care about pure lazyness?
18:42	Chousuke	AWizzArd: yes. and chunked seqs are more performant if the f IS +
18:43	hiredman	AWizzArd: I think the issue is when f is not cheap
18:43	Chousuke	AWizzArd: laziness has a per-item overhead. chunked laziness cuts that overhead down to 1/32
18:43	AWizzArd	if f is not cheap then pmap is great
18:43	AWizzArd	if f is cheap it's still fast enough when map is fully lazy
18:43	Chousuke	no it's not if f is really cheap :)
18:43	Chousuke	if you're mapping lots of cheap operation the laziness overhead accumulates really quickly.
18:44	hiredman	but pmap still does extra work
18:44	Chousuke	operations*
18:44	hiredman	Chousuke: then lets make some strict versions of the sequence functions
18:44	AWizzArd	and what about this vmap or whatever it is called in the PAR branch?
18:44	hiredman	instead of this hybrid nonsense
18:45	Chousuke	AWizzArd: that automatically parallelises itself, taking advantage of a vector's underlying structure. it's fully strict.
18:45	Chousuke	hiredman: but that wouldn't be nice at all :)
18:45	AWizzArd	Chousuke: so, map can be fully lazy, and those people who want to map + can use vmap?
18:45	Chousuke	AWizzArd: but chunked map is not eager.
18:46	Chousuke	AWizzArd: it's still lazy. only 32 times less than the fully lazy one.
18:46	Chousuke	in SOME cases.
18:47	hiredman	Chousuke: it would be nicer than suddenly realizing that map is doing 32 times more work than you thought it was
18:47	dreish	AWizzArd: I think people want to use map the way it is.
18:47	dreish	Here's the old one: http://github.com/richhickey/clojure/blob/a9cb831fe714966e225a5297ef844513fe4a373a/src/clj/clojure/core.clj
18:47	AWizzArd	dreish: I am not sure, I think most people would like map to be lazy.
18:47	dreish	It is lazy.
18:47	Chousuke	hiredman: except due to laziness overhead, doing "32 times the work" will in many cases be cheaper than being fully lazy.
18:48	dreish	We've really got to stop doing this.
18:48	_ato	heh, it's a pity some magic can't measure the time the first element takes and if it's expensive compared to laziness overhead decide to not eagerly do the rest. But the timing would probably be expensive itself
18:48	AWizzArd	map could be lazy again, and on the homepage one could have a link to git, so that people who want the chunked map can check it out, name it map1 and be happy with it.
18:48	hiredman	Chousuke: but not all the cases, and there is no way to tell
18:49	Chousuke	if those 32 items are killing your performace you can mod your algorithm suitably :P
18:49	Chousuke	everyone else can just enjoy a faster map
18:49	Chousuke	and reduce.
18:49	AWizzArd	and this is not possible if map would be fully lazy?
18:49	Chousuke	AWizzArd: no, because laziness has overhead.
18:49	AWizzArd	modifying the algorithm?
18:49	AWizzArd	i see
18:50	hiredman	Chousuke: or you can have a map and a map*, and depending if you want a lazy map or not you can pick
18:50	AWizzArd	why then stick with 32?
18:50	Chousuke	the purpose of the chunking optimisations was to allow people to use map even for cheap operations, where normal laziness overhead would kill performance and you'd have to write a loop.
18:50	AWizzArd	maybe map can do 65536 chunks in one step?
18:50	Chousuke	AWizzArd: because vectors are internally chunks of 32 items and it's a good number.
18:50	AWizzArd	why 32 and not 1, or 2 or 64 or 768?
18:51	Chousuke	as I said above: vectors :P
18:51	Chousuke	and I guess other clojure data structures too
18:52	hiredman	clojurebot: map?
18:52	clojurebot	map is LAZY
18:52	Chousuke	they're internally chunked and processing them a chunk at a time is a lot faster than thunking each item to achieve full laziness.
18:52	hiredman	clojurebot: forget map is LAZY
18:52	Chousuke	that will have to be fixed I guess :)
18:52	clojurebot	I forgot map is LAZY
18:52	AWizzArd	:(
18:52	Chousuke	clojurebot: map is lazy
18:52	clojurebot	'Sea, mhuise.
18:52	dreish	AWizzArd: Seriously, are you having an actual problem with this, or just "if my f were expensive"?
18:52	hiredman	clojurebot: forget map is lazy
18:52	clojurebot	I forgot map is lazy
18:53	hiredman	clojurebot: map is <reply>map and the other sequence functions used to be lazy, but with the advent of chunked sequences, may or may not be lazy, consult your local ouija board
18:53	clojurebot	Ik begrijp
18:53	AWizzArd	dreish: I worry because I don't know if I have an actual problem with it.
18:54	dreish	AWizzArd: Well, that's a difficult problem to solve.
18:54	dreish	It's a lot easier to solve an actual problem in actual code than it is to solve the problem of being dissatisfied that rhickey chose one thing and not the other.
18:55	dreish	But as I keep pointing out, the old code is still out there, and still fine. You could defn map1 and use it in your projects.
18:55	dreish	Maybe it should be part of the core, or contrib at least. I don't know.
18:55	Chousuke	2009-05-25 16:17 "rhickey: reduce+filter+map - 4x faster chunked" :P
18:55	Chousuke	that's when they were still in their own branch
18:55	rhickey_	I someone having an actual problem with map?
18:55	hiredman	Chousuke: I bet they would be even "faster" if we removed all laziness
18:55	rhickey_	is?
18:56	hiredman	so lets do that
18:56	AWizzArd	2009-11-17 00:55 "AWizzArd: reduce+filter+map - 32x less lazy" :P
18:56	dreish	AWizzArd: How are you to know that non-chunked map wouldn't cause you actual performance problems? It most likely would, and those would be the more subtle ones because they would involve lots of little cases scattered all over the place instead of an expensive fn that would stick out in profiling.
18:56	Chousuke	hiredman: you can use a loop
18:56	AWizzArd	dreish: yes, can probably be solved somehow, it is just a new source of uncertainity
18:56	hiredman	Chousuke: you can use a loop, since you are willing to give up laziness
18:56	dreish	AWizzArd: Well, get out there and write some code and find out!
18:57	rhickey_	hiredman: no they wouldn't. The overhead for laziness was less than 10%, now 1/32 of that. You are unlikely to see any benefit and will find a ton of costs as you recalculate things or fully realize intermediate results
18:57	AWizzArd	dreish: i have a big enough code base
18:57	dreish	So why not profile it then?
18:57	dreish	Or benchmark it? Try it with chunks, and then without.
18:57	AWizzArd	dreish: how to try it without chunks?
18:58	rhickey_	map on a non-chunked seq is non-chunked
18:58	rhickey_	i.e. same as always
18:58	dreish	I'm sure there's a more elegant way, but I would copy and paste the relevant functions in core from the URL above.
18:58	notallama	protocols are supposed to be the same as multimethod dispatch with (fn [a & as] (class a)) as the dispatch function, yes?
18:58	AWizzArd	,(chunked-seq? (range 10))
18:58	clojurebot	false
18:58	hiredman	rhickey_: sure, but now (nth x 2) maps f over the 0 to the 31st thing, instead of just 0 to 2
18:58	rhickey_	notallama: no, they don't use the hierarchy system
18:59	_ato	,(chunked-seq? (seq (range 10)))
18:59	clojurebot	true
18:59	dreish	rhickey_: Is there an easy way to convert a chunked seq to a non-chunked seq? Something like (unchunk s)?
18:59	rhickey_	hiredman: there may be a need for a seq-1 which will dribble even chunked seqs as non-chunked when that matters
18:59	AWizzArd	,(first (map pr (range 100)))
18:59	rhickey_	so, I am looking for use cases
18:59	clojurebot	012345678910111213141516171819202122232425262728293031
18:59	AWizzArd	,(first (map pr (seq (range 100))))
18:59	clojurebot	012345678910111213141516171819202122232425262728293031
18:59	rhickey_	not theoretical problems
18:59	AWizzArd	_ato: didn't help :(
19:00	dreish	So far it's just vague worries, not even theoretical problems.
19:00	dreish	But I would think there might be cases where a well-placed seq-1 could help.
19:00	rhickey_	In thinking about this, I came to the conclusion that all we need is a seq1
19:00	AWizzArd	it's scary that something that you thought is guaranteed lazy suddenly isn't
19:00	rhickey_	anything following it would be non-chunked
19:01	dreish	AWizzArd: Why is that scary if you're writing function programs/
19:01	dreish	functional
19:02	hiredman	functional or not, it still burns cpu to run a pure function
19:02	dreish	And it burns CPU to cons atom by atom instead of chunk by chunk.
19:02	dreish	Prove that one is better than the other.
19:02	AWizzArd	well, with pmap i would expect this to happen, to some extent
19:03	rhickey_	yes, the main argument for laziness is to avoid fully realizing intermediate results
19:04	rhickey_	since the infrastructure of all lazy fns is still the same, its simply a matter of feeding then non-chunked seqs when you care - they are still fully lazy in that case
19:04	hiredman	dreish: sure, just map fib over a range, suddenly it takes a whole lot longer to complete
19:04	AWizzArd	rhickey_: it seems that (range 10) is not chunked
19:04	AWizzArd	,(chunked-seq? (range 10))
19:04	clojurebot	false
19:04	Chousuke	I guess a seq1 function would really solve this neatly. you could get full laziness when you really do care about it.
19:04	rhickey_	ah, fib, so, we are not talking about real programs ...
19:04	dreish	hiredman: So few of my programs involve mapping fib, though.
19:04	Chousuke	AWizzArd: the reason is it's not a seq :)
19:04	hiredman	rhickey_: pardon me
19:05	hiredman	rhickey_: dreish asked for proof that one is better than the other
19:05	Chousuke	AWizzArd: as _ato pointed above.
19:05	dreish	In the GENERAL case.
19:05	hiredman	fib just happens to be an easy proof
19:05	rhickey_	I really do care about this, and would like to hear peoples real experiences with chunked seqs
19:05	AWizzArd	Chousuke: but both (range 10) and (seq (range 10)) let map behave in the same way, see above.
19:05	Chousuke	AWizzArd: because map calls seq
19:05	dreish	hiredman: As in, point to a big, real application and show how it performs with and without chunks.
19:05	michaeljaaka	_ato: how to get output from println, right now when I run scripts as standalone apps I can only get ouput via logger
19:06	AWizzArd	dreish: if this is not easy, how can one then know that the current implementation is better?
19:06	hiredman	dreish: do you have such proof?
19:06	hiredman	I have tons of calls to map everywhere
19:06	dreish	No, I don't, I just think it's absurd to burn up this much time yakking about it.
19:06	dreish	If it's a real problem, show why it is.
19:06	_ato	michaeljaaka: err... println should just be going to stdout in a script unless you've redirected it
19:06	AWizzArd	Would it not take some full analyzes of real apps to see if the current map performs better?
19:06	hiredman	so do I have to hunt down ever call to see if there are chunked-seqs anywhere?
19:07	dreish	This is driving me nuts. I'm getting dinner.
19:07	Chousuke	hiredman: if we get this seq1 function you'd just need to add those to places where you really care about full laziness.
19:07	hiredman	Chousuke: sure
19:07	Chousuke	hiredman: which won't be most uses of map :P
19:08	rhickey_	hiredman: as I said, if after trying with chunked seqs you have problems, bring them up and we'll work out solutions
19:08	michaeljaaka	hmmm, when I type in script (println "Hello World") I can see it on output
19:09	michaeljaaka	but when I do that in a callback method of proxy object
19:09	rhickey_	chunked seqs have been in master for a while, and I haven't gotten any complaints
19:09	Chousuke	though seq1 looks ugly ;/ seq* would be neater, but I guess the 1 is kind of hinting at its purpose.
19:09	michaeljaaka	I can't see any output
19:10	_ato	michaeljaaka: strange. how about with (.println System/out "hello") in your callback?
19:10	AWizzArd	rhickey_: it is just that some people (like me) expect filter and map to be fully lazy. When doing Genetic Programming one could try to find the first f for which a good fitness value is found. Those f's could be running for days each.
19:11	AWizzArd	If now someone is convinced that filter will stop immediately as soon a certain fitness value is met will wonder why is program was runing several many hours (or weeks).
19:11	AWizzArd	Now that I am aware about that I would not use find-first anymore
19:11	rhickey_	AWizzArd: I understand the theoretical argument
19:11	AWizzArd	it is totally practical
19:12	AWizzArd	only by accident i stumbled upon this
19:12	rhickey_	only if you have no way to control that
19:12	michaeljaaka	_ato: nothing is showing
19:12	michaeljaaka	_ato: dorun helped
19:12	AWizzArd	now i will use loop instead, but if i didn't find this out tonight I would probably have used find-first
19:12	michaeljaaka	_ato: dorun ( println "Hello there")
19:13	_ato	michaeljaaka: huh... I don't know what would cause that :/
19:13	rhickey_	AWizzArd: but switching your structure is completely unnecessary. filter and find-first are fully lazy when given a non-chunked seq, so all you need are the tools to give them one
19:13	AWizzArd	yes
19:14	qed	i think im getting dumber by the day -- i cannot figure out how to use loop... (loop [n (+ n 1)]
19:14	notallama	my stuff works with regular functions and multimethods, but not protocols. (extending clojure.lang.AFn). as far as i can tell, it should be the same, but i'm getting "Wrong number of args passed to: arrow$eval--114$fn--147$G--103".
19:14	_ato	qed: you need to use recur with loop
19:15	_ato	qed: something like (loop [n n] (recur (inc n)))
19:16	AWizzArd	rhickey_: it seems that map is making some non-chunked seqs chunked.
19:16	rhickey_	AWizzArd: it can't do that
19:17	qed	_ato: yeah, i have my clojure book out, ill figure it out, but thanks
19:17	AWizzArd	[10 20 30] is a non-chunked seq
19:17	AWizzArd	,(first (map pr [10 20 30])) ; will print 10
19:17	hiredman	that is a vector
19:17	clojurebot	102030
19:17	hiredman	not a seq
19:17	hiredman	and vectors produce chunked seqs, I believe
19:17	_ato	,(chunked-seq? (seq [10 20 30]))
19:17	clojurebot	true
19:18	_ato	,(seq? [1 2 3])
19:18	clojurebot	false
19:18	_ato	a vector is seqable (it can be turned into a seq) it's not a seq itself
19:18	AWizzArd	well, then my understanding of chunked-seq? is wrong
19:19	AWizzArd	so, how do i make a seq (but non-chunked) out of a vector?
19:20	rhickey_	AWizzArd: that's what seq1 would be for
19:20	AWizzArd	ok, i understand
19:20	qed	(defn step-seq [result n] (if (= n 1) 1 (recur (conj result n) (step n)))) -- im trying to make (step n) the new value that the loop takes as it's input
19:22	_ato	qed: that code works for me if I define step as 'dec' and call with say n = 10
19:22	_ato	qed: what's the problem?
19:23	qed	wont dec just decrement 10..9..8..7, etc? I want to call a function on the new value of step n, every time i go through the loop
19:24	_ato	(defn step-seq [result n] (if (= n 1) 1 (recur (conj result (f n)) (step n)))) ?
19:24	_ato	where f is that function
19:24	_ato	?
19:24	_ato	or you want to do it to the result of step n, in which case just let-bind the result of (step n)
19:29	qed	_ato: I just get 1 as my return
19:29	qed	something seems broken..
19:30	_ato	oh right
19:30	_ato	that's because if returns 1
19:30	_ato	not results
19:30	qed	ahhhh
19:31	qed	sweet -- thanks _ato
19:38	lisppaste8	rhickey pasted "seq1" at http://paste.lisp.org/display/90536
19:42	dnolen	rhickey: this example brings up another question, so it's now possible to write something analogous Java classes using pure Clojure (i.e. the more confusing bits about deftype & protocols :) ?
19:42	dnolen	analogous to
19:43	rhickey_	deftype can do a particular subset of things - deriving and defining the methods of interfaces
19:43	rhickey_	it can't derive from classes, can't define members not in the interfaces
19:44	rhickey_	if that subset works for you (and it should in most non-interop scenarios), then use deftype, otherwise there is still gen-class
19:44	dnolen	rhickey_: ah, I got burned by that. Tried to derive from an interface and I had some of my own dummy fields.
19:47	rhickey_	you get fields a b c from (deftype Foo [a b c])
19:56	qed	(defn count-and-track [result n] (loop [cnt n size (count (step-seq [] n))] (if (= n 1) result (recur (conj result size) (dec cnt)))))
19:57	michaeljaaka	hi
19:57	michaeljaaka	I have (fn[o] (. o message "Hello") )
19:57	michaeljaaka	wchich returns function
19:57	michaeljaaka	Now I want the same with #() macro
19:57	michaeljaaka	(#(println %1 "Hello"))
19:57	michaeljaaka	doesn't work because it want to be evaluated
19:58	michaeljaaka	I want a reference to that function just like with fn[o] had
19:58	michaeljaaka	(fn[o] println o "Hello" )
19:58	michaeljaaka	should be
19:58	michaeljaaka	but what about # ?
19:59	dnolen	,(do #(println "Hello"))
19:59	clojurebot	#<sandbox$eval__3860$fn__3862 sandbox$eval__3860$fn__3862@2a9403>
19:59	dnolen	michaeljaaka: just remove the surrounding parens
20:00	michaeljaaka	dnolen: thanks!!! :)
20:00	dnolen	np
20:01	arohner_	sigh. really:
20:01	arohner_	* Implements a fast vector class without synchronized
20:01	arohner_	* methods. Replaces java.util.Vector. (Synchronized methods tend to
20:01	arohner_	* be slow.)
20:01	arohner_	from the WEKA source
20:04	qed	best way to find the maximum value in an array?
20:04	maravillas	(ArrayList?)
20:04	qed	err sorry
20:04	qed	a vector
20:05	arohner_	qed: I wrote a little utility function to do it
20:05	arohner_	using reduce
20:06	qed	hmmm, how would you do that?
20:06	arohner_	lisppaste8: url
20:06	lisppaste8	To use the lisppaste bot, visit http://paste.lisp.org/new/clojure and enter your paste.
20:06	lisppaste8	arohner pasted "untitled" at http://paste.lisp.org/display/90537
20:07	tomoj	if it's just numbers
20:07	tomoj	,(reduce max [1 2 3 4 5])
20:07	clojurebot	5
20:07	qed	oh man, im getting dumber and dumber as the day goes on
20:08	arohner_	wow that's a lot prettier
20:08	arohner_	find-max is some of my earliest clojure
20:09	tomoj	(apply max ..) works too but is slower, I wonder why
20:09	Chousuke	hm
20:09	arohner_	tomoj: apply is usually slower than the alternative
20:09	tomoj	yeah, but why?
20:09	tomoj	the &more fn for max just reduces on the rest
20:10	arohner_	~def apply
20:10	arohner_	you have an extra var deref + a copy of the arguments
20:11	Chousuke	,(let [a (vec (range 100000))] (time apply max a))
20:11	clojurebot	java.lang.RuntimeException: java.lang.IllegalArgumentException: Wrong number of args passed to: core$time
20:11	Chousuke	...
20:11	Chousuke	,(let [a (vec (range 100000))] (time (apply max a))=
20:11	clojurebot	EOF while reading
20:11	Chousuke	,(let [a (vec (range 100000))] (time (apply max a)))
20:11	clojurebot	99999
20:11	clojurebot	"Elapsed time: 109.589 msecs"
20:11	Chousuke	,(let [a (vec (range 100000))] (time (reduce max a)))
20:11	clojurebot	99999
20:11	clojurebot	"Elapsed time: 11.49 msecs"
20:12	Chousuke	,(let [a (vec (range 100000))] (time (apply max a))) ; wonder if that was a fluke
20:12	clojurebot	99999
20:12	clojurebot	"Elapsed time: 9.841 msecs"
20:12	arohner_	hah, we're warming up clojurebot's JVM
20:12	tomoj	it's consistently slower for me on (range 1000000)
20:13	Chousuke	,(let [a (list* (range 100000))] (time (apply max a))); hum
20:13	clojurebot	99999
20:13	clojurebot	"Elapsed time: 22.222 msecs"
20:13	Chousuke	,(let [a (list* (range 100000))] (time (apply reduce a)))
20:13	clojurebot	java.lang.IllegalArgumentException: Wrong number of args passed to: core$reduce
20:13	Chousuke	...
20:13	Chousuke	,(let [a (list* (range 100000))] (time (reduce max a)))
20:13	clojurebot	99999
20:13	clojurebot	"Elapsed time: 34.151 msecs"
20:14	tomoj	~def spread
20:14	Chousuke	in any case, reducing over a vector should be faster than over a list
20:14	arohner_	on my box, they each take about 3 ms, with the reduce version about .1 ms faster on average
20:14	Chousuke	I guess the size is too small :P
20:15	tomoj	apply spreads the rest of the arg which looks linear
20:15	arohner_	Chousuke: why should reducing over a vector be faster?
20:15	michaeljaaka	hi
20:16	michaeljaaka	http://pastebin.com/d6d2f2670
20:16	michaeljaaka	I want to define something like this
20:16	michaeljaaka	but I get
20:16	michaeljaaka	http://pastebin.com/d4a04b69a
20:17	Chousuke	arohner_: it's chunked. :)
20:17	arohner_	Chousuke: ah, right
20:17	arohner_	I was thinking in complexity, not implementation
20:18	Chousuke	hm, this is problematic :(
20:19	ngoc	Hi, where can I look for information about meta programming in Clojure? For example, how to list all functions inside a namespace?
20:19	Chousuke	I can't even construct a list of million items in my repl without running out of heap
20:19	Chousuke	building a vector is okay though.
20:19	_ato	ngoc: have a look at: http://richhickey.github.com/clojure-contrib/ns-utils-api.html
20:20	michaeljaaka	how to make that iface is visible in whole function body
20:20	_ato	ngoc: as well as: http://clojure.org/namespaces
20:21	Chousuke	michaeljaaka: you should use a bit more spaces :P
20:21	Chousuke	michaeljaaka: anyway, the iface argument passed to proxy is not evaluated
20:22	Chousuke	ie. it's just a symbol
20:22	Chousuke	in short: you can't do that. You need a macro :)
20:22	michaeljaaka	ugh
20:22	arohner_	michaeljaaka: you can write a macro that will do that though
20:22	ngoc	Thanks, is there a function to convert x_y_z.clj to x-y-z?
20:22	qed	why doesnt max-key work on a {}?
20:23	Chousuke	in general if you define new named things you should use a macro.
20:24	_ato	,(apply max-key key {1 :a, 3 :b, 2 :c})
20:24	clojurebot	[3 :b]
20:24	Chousuke	(defmacro receiver [name iface mapping] `(new EchoReceiver ~name (init-proxy (proxy [~iface] []) ~mapping))) should do. though I can't quite tell what use an empty proxy is.
20:24	_ato	oh you mean on an empty map?
20:24	qed	what goes is max-key if you have to tell it how large the largest key should be?
20:24	qed	nevermind
20:27	ngoc	I mean is there a function to convert a file name "x_y_z.clj" to a namespace name "x-y-z"?
20:29	qed	wow my code is ugly
20:30	qed	it's a good thing project euler stipulates the "if it takes less than 1 minute it's an okay solution"
20:30	qed	because otherwise id fail
20:31	_ato	ngoc: not as far as I know, but it's easy to do youself, just replace _ with - and chop off te .clj
20:32	arohner_	well obviously there's one somewhere, because the compiler uses it
20:32	_ato	oh and change / to .
20:32	arohner_	whether it's accessible to users is a different question
20:35	arohner_	ngoc: I would grep through the src
20:35	arohner_	try looking for the error clojure throws when the file doesn't match the namespace
20:35	_ato	,(clojure.lang.RT/munge "a-b-c!")
20:35	clojurebot	java.lang.IllegalArgumentException: No matching method: munge
20:36	_ato	,(clojure.lang.Compiler/munge "a-b-c!")
20:36	clojurebot	"a_b_c_BANG_"
20:36	_ato	hmm
20:37	dnolen	erg *** slime
20:37	arohner_	aha!
20:37	arohner_	~def root-resource
20:38	arohner_	currently marked private, but at least you can copy it
20:39	_ato	,(@#'clojure.core/root-resource 'baz.foo-bar)
20:39	clojurebot	"/baz/foo_bar"
20:40	qed	Could someone take a look at my code and see if they can optimize it? http://devinwalters.com/posts/21
20:40	qed	my result runs very slow
20:40	_ato	I think ngic wanted the other way around, but yeah, it is just replace _ with - and / with .
20:40	_ato	s/ngic/ngoc/
20:41	rlb	Any suggestions regarding the best "clojure" way to handle input from /dev/input/event? with a timeout? I can already read the events via a DataInputStream, but I'd like to abstract it as a stream of events where you can ask for the next event with a timeout. I could probably work something out with send-off and await-for...
20:42	arohner_	rlb: you could make a lazy seq, or use futures
20:42	arohner_	,(doc future)
20:42	clojurebot	"([& body]); Takes a body of expressions and yields a future object that will invoke the body in another thread, and will cache the result and return it on all subsequent calls to deref/@. If the computation has not yet finished, calls to deref/@ will block."
20:42	rlb	arohner_: will that work with a hardware blocking call?
20:42	_ato	rlb: if I remember correctly java's IO library is broken, you can't use read with a timeout on a file, you have to poll :(
20:42	rlb	i.e. (.read stream) may block indefinitely.
20:42	_ato	it's really annoying
20:42	arohner_	oh,wow
20:42	arohner_	was not aware of that
20:42	rlb	arohner_: I was assuming that via send-off I could just let a thread handle getting the next event.
20:43	michaeljaaka	,(doc let)
20:43	clojurebot	"([bindings & body]); Evaluates the exprs in a lexical context in which the symbols in the binding-forms are bound to their respective init-exprs or parts therein."
20:43	arohner_	futures run in the background
20:43	_ato	you can do it on sockets using nio selectors but I couldn't figure out a way to do it with files
20:43	arohner_	they use the agent pool
20:43	Chousuke	isn't that why they're working on NIO2 :/
20:43	rlb	arohner_: send-off doesn't use the pool, right?
20:43	arohner_	that sounds right, but I'm not 100% certain
20:44	rlb	(though I may do that differently -- I'm not that keen on launching a thread for each event -- may just have a thread that fills a queue...)
20:44	rlb	Anyway, just wanted to make sure there wasn't something obvious I was overlooking.
20:45	rlb	(This is just a toy anyway -- managing a powermate, and looking for double-clicks...
20:45	rlb	)
20:46	arohner_	rlb: IIRC, there's a java lib for interacting with unix somewhere
20:47	arohner_	hrm. looks like there's a bunch of them
20:47	arohner_	anyways, there are several libs out there for making java & posix play nicer
20:47	ngoc	_ato: thanks a lot
20:47	arohner_	that might help
20:51	weissj	anyone know how i can make an ordered map so that items stay in the order they're added?
20:52	rhickey_	weissj: Clojure doesn't come with a data structure with those properties
20:52	chouser	weissj: use a sorted-map and include a globally incrementing counter in the key?
20:53	qed	anyone here know if there's a plugin or something out there that will let me do easy clojure syntax hilighting in rails?
20:53	chouser	I guess finger trees ought to be able to do that.
20:54	rhickey_	chouser: that depends on the meaning of "stay in the order they're added"
20:54	weissj	what are finger trees
20:55	chouser	weissj: they don't exist.
20:55	weissj	i'm not too concerned about keys that are added more than once going to the end of the list vs staying in place
20:55	michaeljaaka	hi, I have another challange
20:55	michaeljaaka	I have http://pastebin.com/d1e94de3c
20:55	michaeljaaka	I want to modify code so use would look like this
20:56	funkenblatt	i guess in a functional language, the idea of "order of insertion" isn't supposed to matter
20:56	michaeljaaka	http://pastebin.com/d4d1f7a3c
20:56	michaeljaaka	I know that there is a memfn
20:56	weissj	chouser: java has LinkedHashMap, is there any way to make that the backing store for a map?
20:56	jensli	weissj, maybe you could create a java LinkedHashMap,
20:57	michaeljaaka	which do what I want but don't know exactly how to use it
20:57	jensli	Oh, you alleady knew about that one.
20:58	weissj	yeah, that's sort of what i'm trying to reproduce here. i have a map of tests to test results, i want the order the tests are run to be preserved
20:58	weissj	there's lots of ways to do this, but i'm trying to stick with built-in stuff as much as possible
20:58	srader	what about array-map?
20:59	weissj	,(doc array-map)
20:59	clojurebot	"([] [& keyvals]); Constructs an array-map."
20:59	weissj	not very helpful doc :)
21:00	rhickey_	http://clojure.org/data_structures describes ArrayMaps
21:02	weissj	rhickey_ ok I suppose what i'm using is a "very small map", probably never more than a few hundred items. linear lookup is probably not going to be noticably slow
21:03	weissj	or maybe i'll just put a counter in the key :)
21:08	michaeljaaka	what is wrong with that?
21:08	michaeljaaka	(import 'java.util.HashMap)
21:08	michaeljaaka	(def a (memfn put ))
21:08	michaeljaaka	(a (java.util.HashMap.) "32")
21:11	rhickey_	(def a (memfn put k v))
21:11	michaeljaaka	ok, that is HashMap, thanks
21:11	_ato	,(macroexpand-1 '(memfn put k v))
21:11	clojurebot	(clojure.core/fn [target__5709__auto__ k v] (. target__5709__auto__ (put k v)))
21:12	rhickey_	#(.put ht k v) more idiomatic than memfn
21:12	rhickey_	memfn predates #()
21:14	weissj	how does one create a comparator to use with sorted-map-by? proxy?
21:15	weissj	or is it just a plain ol function? i am not sure if it's wanting a java Comparator or what
21:15	chouser	weissj: just return a positive, negative, or zero
21:15	chouser	plain ol clojure fns are Comparators. :-)
21:16	weissj	chouser: oh, never occurred tome
21:16	weissj	i guess they might as well be.
21:16	chouser	,(instance? java.util.Comparator #())
21:16	clojurebot	true
21:17	weissj	a fn that doesn't take 2 argsdoesnt' seem like a comparator, but why not eh
21:17	chouser	weissj: yeah, not very useful.
21:17	_ato	,(.compare #() 1 2)
21:17	clojurebot	java.lang.RuntimeException: java.lang.IllegalArgumentException: Wrong number of args passed to: sandbox$eval--3955$fn
21:18	_ato	,(.compare #(- %1 %2) 1 2)
21:18	clojurebot	-1
21:18	_ato	hm :)
21:26	michaeljaaka	any idea how to fix that macro ? http://pastebin.com/d6be08903
21:30	_ato	put parens around dorun
21:30	_ato	actually.. wait.. what's the dorun even for?
21:31	michaeljaaka	it can be skiped
21:31	_ato	oh does EchoSender.message() return a lazyseq
21:32	_ato	michaeljaaka: what's the problem that needs fixing?
21:32	_ato	oh I ssee
21:32	michaeljaaka	this '(message "Hello World") must be expandend in macro to (. o message "Hello World")
21:33	_ato	you need to move some tildes
21:33	_ato	hang on a tick
21:36	_ato	michaeljaaka: http://gist.github.com/236571
21:36	_ato	let me know if you don't see why that worked
21:39	michaeljaaka	_ato: works great!!!
21:39	michaeljaaka	_ato: thanks a lot! exactly that I needed
21:40	michaeljaaka	_ato: these macros are very powerful
21:41	michaeljaaka	_ato: I see why it works
21:41	michaeljaaka	_ato: you may only explain why quote for (message "Hello") is not needed
21:41	_ato	ah
21:42	_ato	because arguments to macros aren't evaluated, so they don't need to be quoted
21:42	michaeljaaka	ok :)
21:42	michaeljaaka	and what about @ what that mean?
21:43	michaeljaaka	&args in macrodef and in its body i can see ~@args
21:43	_ato	ah, ~@ is different to @
21:43	_ato	~@ means splicing unquote
21:43	clojurebot	Gabh mo leithscéal?
21:43	_ato	so
21:44	_ato	suppose v is [1 2 3]
21:44	_ato	then `(foo ~v) => (foo [1 2 3])
21:44	_ato	while `(foo ~@v) => (foo 1 2 3)
21:44	michaeljaaka	I see
21:44	michaeljaaka	super
21:44	michaeljaaka	:D
21:45	michaeljaaka	ok, for today it is enough, thanks again everyone!
21:45	_ato	so yeah you could do: (. o# ~@ufun) instead of (. o# ~(first ufun) ~(second ufun))
21:46	michaeljaaka	I'm using IRC, google groups for the first time to learn new things, and your community is answome
21:47	_ato	:)
21:47	michaeljaaka	_ato: will it work even for method with many arguments?
21:48	michaeljaaka	I know that instead of second ther eshould be rest
21:50	_ato	should do
21:50	_ato	should expand to (. o f a b c)
21:52	michaeljaaka	ok, thanks again and bye!
21:53	qed	I have some slowwww code I'd like to improve. Would anyone mind taking a look at : http://pastie.org/private/k530tmjmfozxvarkzriehw and possibly giving me some suggestions?
21:53	qed	Right now it runs in about 30sec, but that seems really meh, to me -- without changing my approach completely, how could I improve performance?
21:58	arohner_	qed: you could use transients
21:58	qed	arohner_: wuzzat?
21:58	arohner_	http://clojure.org/transients
21:58	arohner_	nm, maps aren't supported yet
21:59	chouser	,(transient {})
21:59	clojurebot	#<TransientArrayMap clojure.lang.PersistentArrayMap$TransientArrayMap@1d0fe80>
21:59	qed	ah, interesting
21:59	arohner_	oh that's right, cgrand fixed them
21:59	arohner_	well then, the docs are out of date
21:59	arohner_	:-)
22:01	qed	how does clojure.org do its syntax hilighting?
22:01	qed	im looking for a good way to do syntax hilighting in rails
22:01	arohner_	where do you see syntax highlighting on clojure.org?
22:01	qed	cgrand's code is be-ay-yootiful
22:01	chouser	clojure.org uses javascript something
22:02	qed	arohner_: on the transient page you linked?
22:02	arohner_	huh, I don't
22:02	qed	not even under example?
22:02	qed	really?
22:02	qed	what browser are you using?
22:02	arohner_	chrome on OSX
22:02	arohner_	though it says the page has been loading since I linked it
22:02	qed	hm weird
22:02	qed	im using safari
22:02	arohner_	chrome and my internet connection are flaky sometimes
22:03	qed	maybe ill just write up a clojure theme for one of the existing hilighting enginers
22:03	qed	engines
22:33	arohner_	is there existing support for making a seq out of a java.util.Enumeration?
22:33	chouser	(doc enumeration-seq)
22:33	clojurebot	"([e]); Returns a seq on a java.util.Enumeration"
22:33	arohner_	chouser: thanks!
22:37	qed	i have some big list of integers, and i have an integer that may or may not be in the list
22:37	qed	what is the fastest way to find out if the integer i have in my hand is inside the list?
22:37	arohner_	,(some #{3} [1 2 3 4 5])
22:37	clojurebot	3
22:37	qed	arohner_: nice! thanks man
22:37	arohner_	,(some #{10} [1 2 3 4 5])
22:37	clojurebot	nil
22:38	qed	that works on lists and vectors and maps?
22:38	qed	or just lists and vectors?
22:38	ohpauleez	You can also use .contains
22:38	ohpauleez	some will return the first true value it finds
22:38	ohpauleez	(just asked this today!)
22:38	qed	:)
22:39	ohpauleez	contains? will work on keys and indexes
22:39	arohner_	chouser: do you know why seq supports iterable, but not enumeration?
22:39	ohpauleez	(contains? [1 2 3 4 5] 5) => false
22:39	ohpauleez	(some #{5} [1 2 3 4 5]) => 5
22:40	chouser	arohner_: I'd have to dig a bit -- I believe seq used to support enumaration but that there was some kind of issue with it, so it was backed off to a separate function.
22:40	leafw	arohner_: enumeration? as in java.util.Enumeration? That is an outdated iterator type with poor semantics.
22:40	arohner_	leafw: yes, I'm aware it sucks. I'm forced to use it for inter-op :-(
22:41	leafw	arohner_: old libs ...
22:41	arohner_	WEKA still uses it in current versions
22:41	leafw	I've been using weka recently
22:41	leafw	it's quite bizarre, wehn it comes to write java classes that use its internals.
22:42	leafw	lots of statics and stateful procedural constructs.
22:42	arohner_	yeah, It's not fun
22:42	leafw	I isolated the damage in a single class file.
22:42	leafw	best luck :)
22:43	arohner_	thanks :-)
23:03	qed	wow
23:04	qed	i think i actually learned some clojure today
23:04	qed	lol -- it took me quite a while to understand that whole loop/recur form for different situations
23:05	qed	kind of embaressing really
23:05	ohpauleez	but once you get it, it makes total sense
23:05	ohpauleez	congrats on the progress
23:06	qed	thanks man -- it's a good community we have here
23:06	qed	lots of eager minds
23:06	ohpauleez	I started working on project to port some of SQLAlchemy's features over to a new project build on contrib.sql and clj-crud
23:06	qed	cool!
23:07	ohpauleez	built**
23:07	qed	i haven't 100% decided on what i'd like to build in clojure
23:07	qed	once there is support for protocols, i was thinking about building sort of a collaborative coding platform
23:08	technomancy	qed: the Emacs implementation for Google Wave uses Clojure on the server-side
23:08	qed	think Github meets irc, meets pair programming in a shared buffer
23:08	qed	technomancy: damn you technomancy !
23:08	technomancy	mwahaaha
23:08	qed	always one step ahead of me phil
23:08	technomancy	well it's not finished yet
23:08	technomancy	still a chance to help out! =)
23:09	ohpauleez	haha, that's awesome
23:09	qed	technomancy: i know you have the basics going on there, but do you see what i was driving at?
23:09	ohpauleez	The other project I had was to create some sort of sandbox
23:09	qed	like you login to github, and you can edit code, in real time, with other committers, on the spot
23:10	technomancy	qed: so a shared buffer but with controls exposed for committing; viewing history, etc?
23:10	ohpauleez	qed: screen + emacs?
23:10	qed	ohpauleez: yeah like that, technomancy yes
23:10	technomancy	I've been thinking of adding that kind of functionality to rudel: http://rudel.sf.net
23:10	qed	just imagine pair programming in irc, like as a fixture of irc
23:10	ohpauleez	rock
23:11	technomancy	qed: that's a big problem though; making an editor that isn't painfully restricted is a huge task in and of itself without even considering the server-side
23:11	qed	like i have my irc window up right now, but what if my drawer was a context-based text buffer, that showed people coding while i was talking in irc
23:11	qed	technomancy: yeah, no doubt
23:11	qed	it's still a great idea though
23:12	technomancy	there is textjure, but I have no idea how complete that is or even if it would be any good as a general-purpose editor
23:12	qed	rudel really has me psyched to do some coding with other people -- i was it wasnt so formal though
23:12	qed	it'd be nice to just drop in on some project, and say "hi, im just going to watch, and might consider adding a few lines"
23:12	technomancy	that's a very interesting idea
23:12	technomancy	from a social angle
23:12	qed	yeah, i feel like it would really facilitate the development of some projects
23:12	technomancy	a collaborative-by-default project.
23:12	qed	like "hey dude, im hanging out over in "some obscure repo" right now"
23:13	qed	"if you wanan talk, come over and code a little bit"
23:13	qed	we all basically do it already
23:13	qed	people using pastie left and right
23:14	qed	explaining concepts to eachother, sharing ideas
23:14	qed	one of the most annoying parts of reading other people's code is that you weren't there, but you could conceivably sit down and watch a project from the sidelines, and know how it all fits together"
23:15	qed	</rant>
23:15	technomancy	you could set up a headless Emacs session with Rudel to subscribe to all buffers on a server and auto-save and auto-commit on an interval to get a persistent session going on.
23:15	arohner_	qed: I suspect you wouldn't get that from watching rhickey code
23:16	arohner_	honestly, I suspect part of the reason clojure has terrible error messages is that rhickey makes so few mistakes he doesn't notice them
23:16	technomancy	hah! that explains everything.
23:17	qed	the real reason the error messages are so bad is that they
23:17	qed	they're actually a cruel joke about error messages
23:18	_ato	I like it, would be interesting
23:18	qed	i didnt want to finish that thought, but when you accidentally hit enter, you're screwed
23:18	qed	_ato: i checked out technomancy's rudel the other night, and then you got me on ethaedit, and i really felt like i got way more out of that
23:19	qed	than just sitting in irc reading contextually isolated lines of information
23:19	qed	you learn faster in that environment
23:21	djork	I have found the horrible stack traces and errors to be pretty easy to cope with after a little time
23:21	djork	null reference my eye
23:22	qed	also, when you think about it, one major problem with irc is that you cannot easily discern many people's lines at once, so there is all of this hate for "flooding", like > 3 lines and you're "flooding"
23:22	qed	all that does is make people less apt to praticipate, or if they do, they go through pastie, which is contextually separate from the discussion, which is a totally uneeded context switch
23:22	qed	im rambling, aren't i?
23:23	_ato	hehe, frankly if Clojure's error messages just said "You suck!" with a line number they'd work about as effectively as they do now a lot of the time.. maybe even more so as you wouldn't have to go hunting through the nested exceptions to find the line number that actually matters :p
23:23	technomancy	qed: I feel that way whenever I use an IRC client that doesn't color nicknames
23:24	qed	i use uncolored nicknames in irssi :X
23:24	technomancy	_ato: maybe that will be an option in swank-clojure 2.0 =)
23:24	leafw	clj contrib had a nice error reporting system, but I can't find anymore. It removed all the non-relevant parts of the stack trace and formated the rest nicely.
23:35	jkkramer	i'm attempting to use clojure-mode's M-x swank-clojure-project and when it asks me for the project root, it doesn't do anything when i press return. this is in Aquamacs. M-x slime works fine. any ideas?
23:35	_ato	jkkramer: do you have all the jars you need (including clojure.jar) in project/lib ?
23:35	jkkramer	i should say, when i press return, it actually prints a newline rather than doing anything
23:36	jkkramer	yes
23:36	jkkramer	the slime repl works as expected
23:37	_ato	I dunno then :/
23:37	_ato	anything in the Messages buffer?
23:38	technomancy	jkkramer: known bug with an older version; try updating
23:39	jkkramer	i thought i did, to 1.6...hmm
23:39	qed	how do you get the fancy slime startup?
23:39	technomancy	or enabling ido-mode; even better
23:39	jkkramer	oh, do i need to rerun clojure-install?
23:39	technomancy	jkkramer: the best way to install is through elpa: http://tromey.com/elpa/install.html
23:40	qed	ah yes, (setq slime-startup-animation on)
23:45	slyrus	jkkramer: bah. you shouldn't need some fancy auto-installer just to get slime up and running. but you do need to be aware that swank-clojure doesn't work with slime's HEAD.
23:45	Draggor	I have a file with a bunch of declare statements, yet when I load later files that would use vars/functions that are declared, clojure claims they are unbound. Why is that?
23:45	Draggor	They're all in the same package
23:45	Draggor	err, namespace
23:45	jkkramer	i installed clojure-mode 1.5 through elpa a while back. i tried to upgrade to 1.6 but now i think my setup is fubar'd. is there an easy way to clear clojure stuff out and start fresh?
23:46	technomancy	don't resist elpa; it's going to be part of emacs 24
23:46	technomancy	jkkramer: just -rm -rf .emacs.d/elpa/clojure*
23:46	slyrus	just because it will be part of it doesn't mean I have to use it...
23:47	technomancy	ok, but I don't have to support you then. =)
23:48	slyrus	fair enough. but when something is legitimately (huh?) broken don't say "use the elpa version" either and we'll have a deal.
23:48	arohner_	Draggor: circular loads?
23:48	technomancy	dear
23:48	technomancy	*deal
23:49	Draggor	arohner_: nope, one clj file that loads the others
23:49	technomancy	I just can't merge the latest swank-clojure to master without breaking clojure-install since the latter works off master
23:49	technomancy	lack of foresight
23:49	hiredman	Draggor: declared how?
23:50	lgas	is there an equivalent of the partition function that will not drop any odd remaining values? e.g. (partition 2 [1 2 3]) returns ((1 2)) but I would like ((1 2) (3))?
23:50	hiredman	lisppaste8: url?
23:50	lisppaste8	To use the lisppaste bot, visit http://paste.lisp.org/new/clojure and enter your paste.
23:50	slyrus	technomancy: you lost me there. are you saying you have a swank-clojure that works with the current SLIME head?
23:50	technomancy	no, but it fixes the problem jkkramer saw
23:52	Draggor	hiredman: I have three declares with a list of names afterwards in a file
23:53	jkkramer	ok, cleared out everything and reinstalled 1.6 clojure-mode and swank-clojure. still seeing the return printing when i do M-x swank-clojure-project
23:53	jkkramer	M-x slime works
23:53	technomancy	jkkramer: maybe turn on M-x ido-mode and see if the problem persists
23:53	technomancy	if it does it's something else that I haven't seen before
23:53	hiredman	Draggor: and how are you using the declared names?
23:54	Draggor	hiredman: function calls and variables. (declare func1) in the declare file. Then in another, later loaded file I might have a form (func1 some-arg)
23:54	jkkramer	awesome, that worked. thanks!
23:54	jkkramer	what's ido-mode, btw?
23:54	technomancy	jkkramer: ido ist awesome
23:55	technomancy	it's like magic press-fewer-keys mode
23:55	hiredman	Draggor: just (func1 some-arg)?
23:55	hiredman	because that's not going to work
23:55	jkkramer	sounds good
23:56	technomancy	"i[nteractively] do [things]"
23:56	_ato	jkkramer: it does fuzzy searching on find-file and buffer switching and such
23:56	technomancy	http://www.vimeo.com/1013263
23:56	hiredman	(func1 some-arg) is going to try and get the function in the var named func1
23:57	jkkramer	thanks for your work on clojure-mode, technomancy. makes it easier for folks like me that want to focus on coding and less on messing with tools
23:57	hiredman	and declare just creates an empty var, if I recall
23:57	Draggor	hiredman: Also trying to use it in a map: {"func1", func1}
23:57	technomancy	jkkramer: glad it's helpful.
23:57	jkkramer	will check that vid out
23:58	technomancy	jkkramer: were you seeing RET-inserts-newline behaviour in elpa's version of swank-clojure? that's odd.
23:58	hiredman	Draggor: unless you have the name inside a function body (the value of the var won't be looked up until you execute the function) then declare is not going to help you
23:58	technomancy	or was it just clojure-mode that you got from elpa?
23:58	cataska	the vid is made by the author of Programming Clojure
23:59	jkkramer	after clearing things out, i marked clojure-mode and swank-clojure for elpa installation
23:59	Draggor	hiredman: Ahh, so could I cheat and just have my map definition in a closure that gets executed upon load?
23:59	technomancy	jkkramer: I'm guessing an old version of swank-clojure may have stuck around; perhaps it was loading out of ~/src/swank-clojure?
23:59	hiredman	Draggor: still not going to help, unless the things you are declare are actually defined before you execute the fn