#clojure – 2009-11-07

2009-11-07

00:20	konr	Is there a way to call a protected method besides using gen-class?
00:20	hiredman	I am glad you asked
00:20	hiredman	http://gist.github.com/226726 <-- wall-hack-method
00:21	konr	hiredman: haha, I just ran into that piece of code wondering if it was trying to do that
00:31	chouser	hiredman: we could smuggle that into contrib. what do you think?
00:34	hiredman	sure
00:35	hiredman	I hate java.uti.Date
00:54	somnium	hey, is this obviously broken for any reason -> http://paste.lisp.org/display/89933
00:54	somnium	trying to make a when-let for multiple bindings and it seems to work without much code
00:55	hiredman	you're missing a quote
00:55	somnium	where? it runs in my repl
00:55	somnium	ah, in the example
00:55	somnium	my bad
00:59	somnium	I meant the semantics I guess, I saw several people asking about multiple when-let if-let bindings recently and it doesn't seem so hard
01:05	chouser	hiredman: I think it has to be a patch via clojure-contrib assembla. Maybe again java-utils?
01:06	hiredman	ok
01:06	chouser	hiredman: go ahead and assign it to me
01:07	hiredman	I remembered my password on the first go round!
01:14	chouser	I don't think any one person watches every commit that goes into contrib
01:17	hiredman	I'm not a member of the space
01:18	hiredman	so I can't do much
01:18	hiredman	https://www.assembla.com/spaces/clojure-contrib/support/tickets/43-add-wall-hack-method-and-wall-hack-field-to-java_utils-clj
01:19	_ato	ah ha! I fixed Chousuke's problem
01:20	hiredman	!
01:20	_ato	all I did was rearrange his classpath a bit
01:20	hiredman	:\|
01:20	_ato	problem was it was compiling itself over itself and getting all confused because gensym makes things change name
01:21	hiredman	interesting
01:21	hiredman	have you seen my reader?
01:21	_ato	no I hadn't
01:21	_ato	there's two competing readers is there? :)
01:22	hiredman	well, competing? I dunno
01:23	_ato	ah so yours is all one function, that probably helps you avoid Chousuke's problem
01:23	hiredman	sort of
01:24	hiredman	it's one top level function
01:24	hiredman	with the letfns, but the letfns are locals
01:24	_ato	oh right, but the inner closures and stuff will still come out as multiple class files
01:33	chouser	hiredman: it's done.
01:33	hiredman	huzzah!
01:34	somnium	are you going to keep the cool name?
01:34	hiredman	it's in the tree with the name
01:34	somnium	nice
01:34	chouser	"hack" in the name is very appropriate
01:35	chouser	add-classpath should probably have that too
01:40	selector-gadget	?quit
01:53	chouser	~tarpit
01:53	clojurebot	Huh?
02:12	konr	Is there a variation of filter that splits the lists into matching and not-matching parts?
02:13	hiredman	reduce
02:13	hiredman	there is split-with but that only works on a sorted list
02:14	hiredman	well
02:14	hiredman	it sort of only works on a sorted list
02:18	somnium	,(doc separate)
02:18	clojurebot	"clojure.contrib.seq-utils/separate;[[f s]]; Returns a vector: [ (filter f s), (filter (complement f) s) ]"
02:19	konr	somnium: oh :( I was starting to code that!
02:20	somnium	konr: I've found that simply reading contrib is a great way to save time :)
02:20	somnium	(and core for that matter...)
02:20	somnium	if only there wasn't so much to read
02:25	somnium	is contrib.core a place for 'soon to be in clojure'?
02:30	lisppaste8	krumholt pasted "problem with agents" at http://paste.lisp.org/display/89934
02:31	krumholt	can somebody see an obvious error with that code?
02:32	hiredman	#'minus is unusual
02:32	hiredman	I think old versions of ants.clj had that(maybe it still does?)
02:32	hiredman	but #' is not needed
02:33	hiredman	what problem are you having?
02:33	krumholt	ok but that doesn't seem to be the problem
02:33	krumholt	i get an out of memory error on the agent
02:34	hiredman	possibly you are queing up a ton of agent actions
02:35	krumholt	Exception in thread "Swank Control Thread" java.lang.OutOfMemoryError: Java heap space
02:35	hiredman	what happens if you up the sleep times?
02:36	krumholt	i tried i went: Exception in thread "Read Loop Thread" java.lang.OutOfMemoryError: Java heap space
02:37	krumholt	:)
02:37	krumholt	not much better
02:37	hiredman	have you tried it outside of slime?
02:38	krumholt	no i will one second
02:38	hiredman	it's humming along here
02:42	hiredman	(#<OutOfMemoryError java.lang.OutOfMemoryError: Java heap space>)
02:42	hiredman	there we go
02:42	hiredman	could just be the number gets too large
02:44	krumholt	hm it's not doing anything if not used from slime
02:44	krumholt	no error
02:44	krumholt	maybe if i wait longer
02:44	krumholt	ah now
02:45	hiredman	I dunno
02:46	krumholt	well thanks anyway
02:46	hiredman	oh duh
02:46	hiredman	use when
02:46	hiredman	not while
02:47	hiredman	,(doc while)
02:47	clojurebot	"([test & body]); Repeatedly executes body while test expression is true. Presumes some side-effect will cause test to become false/nil. Returns nil"
02:47	krumholt	oh man
02:47	krumholt	thanks
02:47	hiredman	,(doc when)
02:47	clojurebot	"([test & body]); Evaluates test. If logical true, evaluates body in an implicit do."
02:47	krumholt	of course i meant when
02:47	hiredman	very easy to overlook
02:48	jamesswift	Hey! I thought I might post here a small program I wrote as a learning exercise http://wiki.github.com/phraemer/Boggle-Solver
02:48	krumholt	hiredman, thanks again could have look hours over that vode without figuring that out
02:48	hiredman	so it was the agent queues overflowing after all :P
02:48	krumholt	yes
02:48	hoeck1	hiredman: good catch : )
02:48	krumholt	vode = code
07:31	javuchi1	what do you thing about CL+FSET versus Clojure?
07:41	Licenser_	what is CL FSET?
07:43	Licenser_	ah google told me
07:44	javuchi1	FSET are inmutable collections for Common Lisp
08:20	Chousuke	yay
08:21	Chousuke	everything builds and all contrib and clojure tests pass!
08:27	gbt	congrats Chousuke :) I was lurking yesterday so I know you were having a few 'minor' troubles ;)
08:27	Chousuke	yeah, _ato solved them for me :P
08:28	Chousuke	apparently it was some classloader thingy and not an actual problem with my code
08:28	gbt	shhhh, you're meant to keep that sort of thing to yourself :D
08:28	gbt	thats ok then. So is this reader just for yourself or an addition to clojure proper?
08:30	Chousuke	Well, I started writing it just to see how it'd turn out.
08:31	Chousuke	I think it'll still need some tweaking before I dare suggest it for inclusion though. But at least I have something that works as a base now.
08:32	gbt	I'm a noob, so its beyond anything I can understand. But its great to see so many people actively trying to improve what is already an impressive language :)
08:34	The-Kenny	Chousuke: What's the difference between yours and the "original" reader?
08:34	Chousuke	mine is written in Clojure :)
08:35	The-Kenny	Oh, that's cool :)
08:35	Chousuke	it also uses multimethods, but otherwise it's pretty similar to the java reader.
08:53	thomaslee	compojure question -- any ideas why the :user-id session variable would not be set despite the redirect-to in login-action being executed? http://pastebin.com/d29a8c7ed
08:54	thomaslee	well it's not an actual redirect-to, but a redirect all the same. :)
10:03	scode	I'm looking to implement an LRU cache based on immutable data structures. I can't figure out how to do so using Clojure data structurs, due to the problem of keeping track of recenticity.
10:04	scode	Effectively I need an efficient priority queue (the priority in this case being the recenticity) where the priority of individual items can change. It's fine if it's log(n) or better, but n is not acceptable.
10:04	scode	Am I missing something obvious?
10:04	scode	If the clojure vector did logn32() removal at arbitrary indexes I'd be okay.
10:06	The-Kenny	:)
10:06	The-Kenny	wrong window, sorry.
10:26	chouser	scode: would a sorted map do it?
10:26	scode	chouser: I thought so at first, but as far as I can tell I can't "grab the first element" out of a sorted map.
10:27	scode	Or rather, I can't produce the "rest" of the sorted map.
10:27	chouser	use 'first' to get the first, and then remove it from the map
10:27	scode	I think. :) It was one or the other.
10:27	scode	Right. I think I found some problem with that. reconsiders
10:28	chouser	I've not actually used a sorted map that way, so there may be a use case where it falls down, but it's the most likely of what we've got so far.
10:28	chouser	finger trees should be able to do it too, but they're not ready yet.
10:30	scode	Was not aware of those (http://en.wikipedia.org/wiki/Finger_tree) - I'll read up on them. Thanks :)
10:30	scode	As for sorted map, I think you're right. I think I made a mistake when I went down that path before.
10:36	scode	Yeah. I'll need an additional mapping to cross-reference values in that sorted map, but it should work.
10:37	chouser	scode: if your keys are not naturally unique, you can use a vector of [priority uuid] as the key
10:38	chouser	where uuid is not necessarily anything industrial-strength, just something to keep your priorities from colliding.
10:38	chouser	scode: If you get it working (or find why it doesn't), I'd appreciate knowing about it. The question comes up occasionally.
10:39	scode	chouser: I was planning on keeping an ever increasing counter to keep track of recencitity.
10:39	chouser	ah, so naturally unique. good.
10:39	scode	The keys will be uique, but since the sorted map is sorted on key (which in this case is recenticity), I must keep a separate mapping to find the [recenticity, key] tuple for a given key
10:40	scode	chouser: And yes I'll let you know.
10:40	scode	chouser: I am doing this to make some comparisons on the effects on GC performance/latency as a result of avoiding mutations (making incremental collections less expensive).
10:42	chouser	Clojure's sorted-maps haven't gotten the same optimization effort that its hash-maps and vectors have gotten, I think.
10:42	chouser	no transient sorted-map for example.
10:42	scode	Transient, in this context?
10:42	scode	I do not care too much about absolute performance right now, as long as complexity is reasonable.
10:42	scode	It's more about seeing how CMS/G1GC behaves with no writes to older generations.
10:43	scode	(Or very few writes; there won't be zero.)
10:43	scode	And an LRU is a good practically relevant use case. I wasn't able to get good enough behavior on multi-gigabyte heaps mostly containing LRU-cached data.
10:44	chouser	clojurebot: transient?
10:44	clojurebot	Don't bash in place
10:44	chouser	hmph. I'm not finding useful docs on transients.
10:44	scode	chouser: Oh, you're saying the implementation is in fact mutation based?
10:44	chouser	clojurebot's advice is accurate, but a bit incomplete. :-)
10:44	scode	Rather then copy-on-write "all the way down".
10:45	scode	That was my interpretation of 'don't bash in place'. So if it's not transient, I guess it's bashing in place? :)
10:46	chouser	scode: hash-map and vector support a special "mode" where some mutation is allowed for performance.
10:46	scode	chouser: http://clojure.org/transients
10:46	chouser	ah, yes, that's it.
10:46	scode	Ah, I didn't know that. I thought there was never any mutation.
10:46	scode	I'll read that one. A bit later; gotta go away atm.
10:46	scode	chouser: Thanks for your help!
10:46	chouser	scode: sure
10:48	scode	But I did peak right away; sounds like it's transient mutation in the sense of temporary values during creation, rather than any mutation of the actual data structure being operated upon. Which is fine in this case; writing to newly created data is okay for my purposes.
10:50	chouser	scode: you may be being mislead by the introduction. transient can be used later in the life of the collection if its useful, for example for "batch updates"
10:51	chouser	If you're doing one-at-a-time inserts and updates to your maps, you're likely to not call anything that uses transient/persistent! internally and using them explicitly yourself may not change very much.
11:38	krumholt	hi, does anyone have java completion in emacs?
11:51	leafw	krumholt: goodle knows.
11:51	leafw	gooGle
11:53	krumholt	sry i didn't mean java java completion but clojure java completion. so it can complete i.e (.printSt to (.printStackTrace
11:55	kefka	,(class (- 12345678901234567890 12345678901234567889))
11:55	clojurebot	java.lang.ExceptionInInitializerError
11:55	kefka	,(- 12345678901234567890 12345678901234567889)
11:55	clojurebot	java.lang.ExceptionInInitializerError
11:55	kefka	,(- 6 5)
11:55	clojurebot	1
11:55	kefka	,1
11:55	clojurebot	1
11:55	kefka	,12345678901234567
11:55	clojurebot	12345678901234567
11:55	kefka	,12345678901234567890
11:56	clojurebot	12345678901234567890
11:56	kefka	,(- 12345678901234567890 1)
11:56	clojurebot	java.lang.ExceptionInInitializerError
11:56	kefka	,(- (new java.lang.BigInteger 6) (new java.lang.BigInteger 5))
11:56	clojurebot	java.lang.ClassNotFoundException: java.lang.BigInteger
11:56	kefka	,(- (new java.math.BigInteger 6) (new java.math.BigInteger 5))
11:56	clojurebot	java.lang.IllegalArgumentException: No matching ctor found for class java.math.BigInteger
11:57	kefka	,(- (new java.math.BigInteger "6") (new java.math.BigInteger "5"))
11:57	clojurebot	1
11:57	kefka	,(- (new java.math.BigInteger "12345678901234567890") (new java.math.BigInteger "1"))
11:57	clojurebot	12345678901234567889
11:57	kefka	,(class (- (new java.math.BigInteger "12345678901234567890") (new java.math.BigInteger "12345678901234567889")))
11:57	clojurebot	java.lang.Integer
11:58	kefka	,(class (- 12345678901234 12345678901233))
11:58	clojurebot	java.lang.ExceptionInInitializerError
11:58	kefka	,(class (- (long 12345678901234) (long 12345678901233)))
11:58	clojurebot	java.lang.ExceptionInInitializerError
11:58	kefka	weird.
11:58	chouser	those all work fine in my repl
11:58	kefka	they work fine in mine too
11:58	kefka	although (- 12345678901234567890 12345678901234567889) is an Integer
11:58	gbt	krumholt: clojure-mode seems to do it. well I just tried (.printSt and it worked
11:58	kefka	while (- 12345678901234 12345678901233) is a Long
11:59	kefka	Why does BigInteger get downcast but not Long?
11:59	kefka	In my mind, (long 1) is a bit pathological.
11:59	kefka	Obviously, (unchecked-subtract 12345678901234 1245678901233) should be a Long.
12:00	kefka	(long 1) is pathological because of the nasty map behavior
12:00	kefka	,(get {(long 1) "one"} 1)
12:00	clojurebot	nil
12:00	krumholt	gbt, hm doesn't work for me for some reason
12:01	gbt	krumholt: what version of clojure-mode you got? I'm on 1.5
12:01	onigiri	kefka, chouser what's the problem? all these clojurebot requests made me curious
12:01	gbt	I'm new though, so I don't know if its always worked?
12:02	kefka	The clojurebot exception is not the problem; we don't have that in our Repls.
12:02	kefka	Subtle issue with Clojure is that while 1 and (long 1) are semantically equal, hash-maps treat them as different.
12:02	krumholt	gbt, uh i am on 1.0
12:02	krumholt	gbt, thanks gone update
12:03	kefka	onigiri: So that can be an issue if you're dealing with, say, sparse matrices/vectors
12:03	kefka	,(get {(long 4) "four"} 4)
12:03	clojurebot	nil
12:03	onigiri	kefka: oh I see, thanks
12:03	kefka	Also...
12:03	kefka	,(hash-set 1 (long 1))
12:03	clojurebot	#{1 1}
12:04	kefka	,(sorted-set 1 (long 1))
12:04	clojurebot	#{1}
12:04	kefka	I think that if you're relying upon numerically equal things comparing equal, better to use sorted maps/sets for now.
12:04	kefka	I generally think (long 1) is a pathological value but there are times when it's appropriate (e.g. a function takes only a long).
12:04	kefka	A java function that is... obviously, clojure numerical functions don't care.
12:12	chouser	there are several objects that can represent 1 -- if you're using them as keys in a collection it's probably worth making sure you always use the same type.
12:12	chouser	using numbers as keys
12:17	Chousuke	hmm
12:17	Chousuke	,(get {(long 4) "foo"} (long 4))
12:17	clojurebot	"foo"
12:26	kefka	chouser: agreed, but this is hard to guarantee.
12:26	kefka	Because (- 12345678901234567890 12345678901234567889) is the Integer 1 but (- 12345678901234 12345678901233) is the Long 1.
12:26	kefka	Which is counterintuitive. It'd be better if - were consistent, IMO.
12:26	kefka	Either it always downcasts, or it never does.
12:27	kefka	* In my example, the first is a subtraction of two BigIntegers and the second is one of two Longs
12:53	cup	howdy, is there a standard recommendation for how to structure a compojure site?
13:12	javucci	hello there
13:48	ericthorsen	Is there a correlate to proxy-super for gen-class(ed) class methods?
13:49	rhickey	ericthorsen: see :exposes-methods in the gen-class doc
13:49	rhickey	should do the trick
13:49	rhickey	if slightly differently
13:50	ericthorsen	rhickey: I saw that..just checking to see if there was a magic function. Thanks!
14:10	javi_	rhickey, what do you think about FSET?
14:11	rhickey	javi_: I haven't used it, but it seems like a good idea if you are in CL
14:16	javi_	i see the problem with FSET is the interaction with the remaining Lisp
14:29	scode	chouser: I have a preliminary LRU now at http://github.com/scode/plrutest/
14:30	scode	chouser: But it's definitely preliminary (needs docs, needs some additional features, and can definitely be optimized)
14:41	chouser	scode: great!
14:41	chouser	scode: another perfect candidate for deftype/protocols once those are ready.
14:48	djpowell	i've just been added to the contrib page; is it possible to subscribe to clojure-dev without a google account?
15:06	ericthorsen	rhickey: Anything I have to so for overloads on the expose methods for gen-class? Cannot seem to get it to see a no arg version of the function...I'm passing this to both versions
15:06	ericthorsen	...:exposes-methods {read superRead unread superUnread}
15:06	ericthorsen	both read and unread have overloads
17:02	scode	chouser: Amusingly when I googled the first hit was what you just said - apparantly Google indexes faster than I catch up on IRC
17:02	scode	chouser: But were you referring to http://www.assembla.com/wiki/show/clojure/Datatypes (deftype/protocols)?
17:04	rhickey	ericthorsen: what you get is another method with the name you specify, to call use (.superRead this)
17:05	chouser	scode: ooh, if so that's new -- google's generally been a couple weeks behind on our irc logs
17:05	chouser	scode: but yes, datatypes
17:08	scode	Roger, sounds interesting. I admit to not having kept up with the movements in clojure as well as I would like.
17:21	ben_m	Greetings :)
17:21	ben_m	Is there a way to load some definitions from a file into the REPL, so I can do interactive development?
17:23	Chousuke	(doc load-file)
17:23	clojurebot	"([name]); Sequentially read and evaluate the set of forms contained in the file."
17:24	Chousuke	(doc load) ; this also
17:24	clojurebot	"([& paths]); Loads Clojure code from resources in classpath. A path is interpreted as classpath-relative if it begins with a slash or relative to the root directory for the current namespace otherwise."
17:24	ben_m	Thanks :)
17:25	ben_m	Would you generally recommend Clojure to a functional programming fan (I love Haskell, Common Lisp, ...), who likes the JVM, but not Java the language?
17:26	ben_m	From what I've seen when I last played with Clojure is that you do have to use Java-esque code frequently when interfacing with the JVM.
17:31	_ato	ben_m: yes, idiomatic Clojure is very functional.
17:32	ben_m	This mentality of "embracing the jvm" puts me off a bit
17:32	ben_m	But we'll see :)
17:34	_ato	well, it's a choice between that and rewrite everything yourself, I guess. In practice I find interfacing with Java code works fine. If the library has a particularly horrible API a couple of wrapper functions and the odd macro can clean it up
17:35	ben_m	Sounds reasonable.
17:46	fradiavalo	Hi, is it possible to write multi-line code on slime (swank clojure)?
17:47	_ato	fradiavalo: in the REPL?
17:48	fradiavalo	_ato: yes
17:48	_ato	yeah... just don't close your parens and it'll continue on the next line
17:48	_ato	although I prefer to do multi-line things in a .clj for and evaluate with C-x C-e
17:48	_ato	s/.clj for/.clj file/
17:49	javi_	who's using clojure?
17:49	javi_	is enterprise ready?
17:49	fradiavalo	ah, I see. I am using paredit mode, so that doesn't let me not enter an closing paren
17:50	_ato	javi_: gosh I hope not. Most thing labeled "enterprise" are terrible. ;-)
17:50	fradiavalo	I can't just put my cursor before the closing paren and hit return
17:50	ben_m	fradiavalo: ^d then press return?
17:50	ben_m	I don't know about paredit so that's just a guess :)
17:50	javi_	_ato, then i don't understand why to use the jvm, as it is very much enterprise "oriented"
17:51	javi_	in other words
17:51	javi_	is clojure ready in reability and stability terms?
17:51	fradiavalo	ben_m: thx, but that doesn't work
17:52	javi_	reliability
17:52	ben_m	fradiavalo: What keeps you from writing the code in some buffer and loading that?
17:52	ben_m	As _ato said
17:52	fradiavalo	ben_m: yeah, I could do that. Its just that I love typing at the REPL :)
17:53	ben_m	heh
17:53	ben_m	Well, you just type at another buffer and evaluate the last s-expression.
17:53	ben_m	I think you don't even have to save the buffer or anything.
17:53	ben_m	I'm a Vim user who uses Emacs only for Common Lisp and Haskell, so these are all just assumptions.
17:53	fradiavalo	You mean just like other lisp expressions in the scratch buffer?
17:53	ben_m	right
17:54	fradiavalo	I will give it a shot
17:54	_ato	javi_: uhh... yes, it doesn't crash randomly? is that what you mean by reliable? ;-)
17:55	fradiavalo	ben_m: That does work if I turn on clojure more on the buffer
17:55	ben_m	yeah
17:55	ben_m	that's pretty nice :)
17:55	fradiavalo	ben_m: yeah! Thanks
17:55	ben_m	I should tidy up my .emacs file (that's what is keeping me from using Emacs more) and get used to it for clojure
17:55	ben_m	fradiavalo: Thank _ato for that
17:56	fradiavalo	yeah thanks _ato too
17:56	fradiavalo	ben_m: Take a look at emacs starter kit
17:57	_ato	fradiavalo: another handy key combo is C-c C-c which will compile the top-level form you're in the middle of. Which is great for working on functions as you don't have to navigate to the end of it to compile it
17:58	fradiavalo	_ato: Yeah, that is pretty cool. I also like how code navigation just works
17:58	ben_m	code navigation? :)
17:58	fradiavalo	ben_m: Jumping to definations and back
18:00	_ato	ben_m: M-. to go to a definition and M-, to go back
18:00	ben_m	That's nice.
18:02	ben_m	I hate configuring Emacs :D
18:03	fradiavalo	It is not possilble to change your classpath from the REPL, is it?
18:04	_ato	there's an add-classpath function, I don't know how reliably it works though
18:05	fradiavalo	I will take a look at that. Java's classpath is so rigid, I still haven
18:06	fradiavalo	haven't figured out a system to manage my code well
18:06	ben_m	yeah...
18:06	Raynes	fradiavalo: I believe the add-classpath function is rather frowned upon.
18:07	Raynes	Usually when people recommend it they say something along the lines of "But don't get too used to it."
18:08	fradiavalo	Raynes: :), I will keep that in mind
18:08	fradiavalo	Anything that makes classpath managable has to be black magic.
18:08	Raynes	Indeed.
18:10	fradiavalo	What makes Raynes not hate it now?
18:10	Raynes	I got used to it.
18:11	fradiavalo	How you keep from adding every new jar to it?
18:11	fradiavalo	How do* you
18:17	_ato	fradiavalo: personally I just have ~/.clojure/* on my classpath an symlink in any jars I need. not great but I haven't bothered to come up with something better. If it's a more complex project (like some existing java monster with a million jars) I'll put the swank.jar in it's classpath, start it from a terminal and use M-x slime-connect in emacs
18:17	_ato	I think some of the maven users came up with some emacs magic for automatically switching the classpath depending on the project you're working on, reading the dependencies from pom.xml. I haven't looked into that yet
18:19	_ato	yeah, here we go: http://github.com/talios/clojure-maven-plugin
18:19	_ato	they have a clojure:swank task
18:19	fradiavalo	_ato: I have something similar to you now. But sometimes when I add symlinks to new jars, it doesn't work. I will take a look at Maven
18:19	fradiavalo	thanks!
18:29	st3fan	hmm is there a (find-first collection fn) ?
18:29	st3fan	i need to find a matching item in a (small) sequence
18:30	st3fan	sequence of maps
18:31	_ato	,(use 'clojure.contrib.seq-utils)
18:31	clojurebot	nil
18:31	st3fan	ah seq-utils :-)
18:32	_ato	,(find-first #(> % 4) [1 2 1 3 6 3 2])
18:32	clojurebot	6
18:32	_ato	not sure if that's exactly what you meant
18:35	_ato	,(find-first :a [{:b 2} {:c 3} {:d 7, :a 4}])
18:35	clojurebot	{:d 7, :a 4}
18:37	st3fan	yeah it is
18:37	st3fan	i should really use a map though
18:37	st3fan	to do a direct lookup
18:40	ben_m	fradiavalo: the emacs starter kit is great, thanks for the recommendation
18:41	fradiavalo	ben_m: you are welcome. Thank the author for it :)
18:44	fradiavalo	ben_m and _ato: C-j will do \n and indent at the slime REPL :)
18:45	ben_m	mhh
18:45	ben_m	M-x slime opens up two buffers with a REPL
18:45	ben_m	:/
18:46	fradiavalo	ben_m: one is inferior lisp, avoid that one
18:47	ben_m	ok
18:47	ben_m	Still ugly :D
18:47	_ato	fradiavalo: ah, cool. that's handy. That reminds me I should turn on paredit at the REPL was well (I use it when editing source)
18:49	fradiavalo	yeah paredit is awesome, it feels a little weird at first, but once you are a little used to it, it becomes indispensible
18:49	ben_m	I feel that way about the Emacs in general
18:49	fradiavalo	true
18:49	ben_m	I'm a Vim poweruser though
18:50	ben_m	I'm not used to editing things in Emacs :/
18:50	_ato	ben_m: I think inferior-lisp is the stdin/stdout of the clojure process, and then the other REPL slime connects to via a socket which does all the funky slime stuff
18:50	_ato	eg. if you use slime-connect to a remote process you don't get inferior-lisp
18:50	ben_m	When you load a file via C-c C-l, both buffers load the file
18:52	digash	lets say I have a vector of integers. How do I find the index of the smallest one?
18:53	_ato	,(apply min-key second (indexed [90 50 40 70 30]))
18:53	clojurebot	[4 30]
18:53	_ato	,(first (apply min-key second (indexed [90 50 40 70 30])))
18:53	clojurebot	4
18:54	_ato	there's probably a simpler way
18:54	djpowell	,(doc indexed)
18:54	clojurebot	"([s]); Returns a lazy sequence of [index, item] pairs, where items come from 's' and indexes count up from zero. (indexed '(a b c d)) => ([0 a] [1 b] [2 c] [3 d])"
18:54	djpowell	is that from contrib?
18:54	djpowell	,indexed
18:54	clojurebot	#<seq_utils$indexed__697 clojure.contrib.seq_utils$indexed__697@8fc519>
18:54	djpowell	k
18:57	_ato	,(first (apply min (indexed [90 50 40 70 30])))
18:57	clojurebot	java.lang.ClassCastException: clojure.lang.PersistentVector cannot be cast to java.lang.Number
18:57	_ato	oh right
18:58	fradiavalo	,(doc min-key)
18:58	clojurebot	"([k x] [k x y] [k x y & more]); Returns the x for which (k x), a number, is least."
19:02	digash	thanks, for the pointers i will need to adapt it to clojure 1.0 w/o contrib
19:08	st3fan	hmm what is the non-read-macro equivalent of #'foo ?
19:09	st3fan	isn't that (function foo) in common lisp?
19:09	djpowell	(var foo)
19:09	st3fan	ah :-)
19:10	digash	,'#'foo
19:10	clojurebot	(var foo)
19:12	st3fan	hmm does not work in my case
19:12	st3fan	i need to do something like this:
19:12	st3fan	(find-first #(= "Test" (:webservice-action (meta (var %)))) [test-action hello-action])
19:12	st3fan	where the actions are functions with :webservice-action meta-data
19:13	ben_m	Has anybody used java-sdl with clojure with success?
19:17	chouser	st3fan: resolve
19:18	chouser	,(meta (resolve "map"))
19:18	clojurebot	java.lang.ClassCastException: java.lang.String cannot be cast to clojure.lang.Symbol
19:18	_ato	st3fan: it doesn't work because [test-action] resolves to a value so your vector contains two functions, not two symbols/vars
19:18	chouser	,(meta (resolve 'map))
19:18	clojurebot	{:ns #<Namespace clojure.core>, :name map, :file "clojure/core.clj", :line 1705, :arglists ([f coll] [f c1 c2] [f c1 c2 c3] [f c1 c2 c3 & colls]), :doc "Returns a lazy sequence consisting of the result of applying f to the\n set of first items of each coll, followed by applying f to the set\n of second items in each coll, until any one of the colls is\n exhausted. Any remaining items in other colls are ignored. Function\n
19:19	_ato	,(map #(meta (resolve %)) '[inc dec])
19:19	clojurebot	({:ns #<Namespace clojure.core>, :name inc, :file "clojure/core.clj", :line 618, :arglists ([x]), :inline #<core$fn__4427 clojure.core$fn__4427@4e1e4>, :doc "Returns a number one greater than num."} {:ns #<Namespace clojure.core>, :name dec, :file "clojure/core.clj", :line 763, :arglists ([x]), :inline #<core$fn__4516 clojure.core$fn__4516@86b899>, :doc "Returns a number one less than num."})
19:19	_ato	,(map #(meta (resolve %)) [inc dec])
19:19	clojurebot	java.lang.ClassCastException: clojure.core$inc__4430 cannot be cast to clojure.lang.Symbol
19:30	Raynes	How would I repeat a function call a set number of times? I naively figured that (repeat 6 (rand-int 10)) would work, but I was wrong. :>
19:31	Raynes	What I'm trying to do is get a sequence of 6 random numbers.
19:31	raek	does the function have side effects?
19:31	raek	ah
19:31	Raynes	The function is rand-int.
19:32	raek	(doc repeatedly)
19:32	clojurebot	"([f]); Takes a function of no args, presumably with side effects, and returns an infinite lazy sequence of calls to it"
19:32	raek	,(take 6 (repeatedly #(rand-int 10)))
19:32	clojurebot	(9 4 7 9 6 0)
19:32	Raynes	I see.
19:32	Raynes	I should have thought of that. :)
19:32	Raynes	Thank you.
19:33	raek	np
19:44	ben_m	groar
19:44	ben_m	paredit is annoying :D
19:45	_ato	hehe, takes getting used to
19:45	ben_m	I have (((/ n 2)))
19:45	ben_m	Because I removed some things
19:45	ben_m	And I can't remove the outer parantheses :P
19:45	_ato	M-s
19:45	st3fan	_ato, i still don't fully understand the function meta-data stff, but i'll read more first
19:46	ben_m	I have to use Esc-s because urxvt grabs M-s, but thanks :)
19:48	_ato	yeah, the whole point of paredit is the hotkeys for manipulating S-expressions, until you intern them it is a bit annoying, but then you can't live without it
19:49	ben_m	guess so
19:50	_ato	st3fan: yeah it's a little counter-intuitive. metadata is associated with vars, not the actual functions the var is bound to. I don't remember why that is, there's no doubt a good reason
19:51	_ato	oh wait.. I just remembered why it is :p
19:52	_ato	it's to do with importing things from namespaces. for example you can mark a var private and it won't be imported and you want to be able to do that whether the var is bound to a function or something else
20:44	fradiavalo	ben_m: C-q (paren) to insert single parens
20:45	fradiavalo	and C-u del to delete single parens
20:46	ben_m	Thanks :)
20:50	fradiavalo	I wonder if there is a functino ot fix missing parens
20:51	ben_m	I know that there's a function to close all open parens at the end, even without paredit
20:51	ben_m	Don't remember the name or key though
20:52	fradiavalo	I will try to find that
20:55	ben_m	C-c C-q slime-close-parens-at-point
20:56	ben_m	I read about it in Practical Common Lisp
20:57	ben_m	There _is_ a slime-close-all-parens-in-sexp
20:57	ben_m	C-c C-]
20:57	fradiavalo	excellent! Thanks
21:15	Raynes	ben_m: While I'm memorizing the important keys for Paredit, I've set my desktop background to the Paredit cheatsheet. Comes in handy.
21:19	cup	when fetching n items from a vector, is there a performance difference between getting from the front or the back?
21:21	ben_m	Raynes: I use a tiling window manager, so I don't really have a desktop :)
21:22	ben_m	Raynes: I'll just keep it open in a browser though until I memorize it.
21:22	ben_m	Night guys :)
22:30	shmay	i'm going line by line through ants.clj to learn clojure. i'm looking at this line: (defn place [[x y]] (-> world (nth x) (nth y))). why does it use the '->' operator, and what exactly does that operator do (i've looked at the online examples, but am still a bit confused)?
22:31	hiredman	it threads an expression
22:32	hiredman	(nth (nth world x) y)
22:32	hiredman	or
22:32	hiredman	(-> world (nth x) (nth y)) ~ (-> (nth world x) (nth y)) ~ (nth (nth world x) y)
22:36	shmay	hiredman: thanks, so it embeds the expression with the previous expression?
22:36	chouser	shmay: -> is never required, it just allows a smoetimes more convenient arrangement of the code
22:36	hiredman	shmay: the next expression
22:36	hiredman	,(-> 1 inc inc inc)
22:36	clojurebot	4
22:37	shmay	hiredman: right, i think i got it, thanks a lot
22:37	hiredman	there is also a new related macro
22:37	hiredman	->>
22:38	hiredman	,(-> 1 (nth [:a :b]))
22:38	clojurebot	java.lang.ClassCastException: clojure.lang.PersistentVector cannot be cast to java.lang.Number
22:38	hiredman	oh
22:38	hiredman	,(->> 1 (nth [:a :b]))
22:38	clojurebot	:b
22:39	annealer	i have what's probably a really dumb macro question. does what im trying to do in this trite example code https://gist.github.com/97ffff695c43b28d3f2b make sense? and if so, why doesn't it.... work
22:40	hiredman	:(
22:40	hiredman	parens should not be on a new line like that
22:41	hiredman	and it looks like you are trying to call a macro at runtime
22:41	hiredman	which you should not do
22:42	shmay	so it becomes the 3rd item rather than the 2nd?
22:43	hiredman	shmay: it becomes the last
22:43	shmay	gotcha
22:43	hiredman	,(-> 10 range (->> (map inc)))
22:43	clojurebot	(1 2 3 4 5 6 7 8 9 10)
22:45	shmay	:)
22:51	annealer	hiredman: well, im not trying to call a macro at runtime so much as i'm trying to define a macro that calls other macros based on its arguments
23:31	_ato	annealer: is this what you're trying to do? http://gist.github.com/229099
23:31	_ato	not sure as your gist seems to have dissappeared
23:42	annealer	_ato: pretty much. thanks