#clojure – 2008-12-17

2008-12-17

00:05	bradbev	are def's evaluated at compile time when AOT compilation is used?
00:06	bradbev	I think they are, because one of my defs is (def foo (JFrame. "foo")), and when compiling using ant I get problems because Swing can't be found
00:10	Chouser	everything gets evaluated when you compile -- it's just like a normal run, except generated class files are saved out along the way.
00:11	bradbev	so how does that actually work if I construct Java objects in defs - how do they get saved?
00:12	hiredman	they don't
00:12	Chouser	oh, good, because I didn't know.
00:12	Chouser	hiredman: the code to generate them gets compiled and then new ones are made when the compiled code gets run?
00:13	hiredman	yeah
00:13	hiredman	mean, it must right?
00:13	hiredman	the other way is just crazy
00:13	bradbev	which also means that at compile time the defs need to be able to execute
00:13	bradbev	my use-case is that I have a hash-map to describe a gui & a couple of functions to load/show it
00:13	hiredman	bradbev: there is some var that is set at compile time you can (if ) around
00:13	bradbev	I construct the Swing objects in the def
00:16	dhaya	this seems relevant http://groups.google.com/group/clojure/msg/169922392f950839 (the note above print duping them and reading back later). So it does look like they get saved after all?
00:17	hiredman	but rhickey did not go through and add print-dup ability to all java objects
00:17	hiredman	clojurebot: rhickey?
00:17	clojurebot	he works hard so you don't have to
00:18	bradbev	hmm, I'm not sure that's the same thing at all
00:18	hiredman	print-dup is for clojure data structures I think, because certain clojure data structures can have different underlying impls
00:18	bradbev	if the def was not evaluated at AOT, but was evaluated at load then I'd be fine
00:19	dhaya	There is a compile-files flag that you can use to prevent evaluation during AOT compilation.
00:20	hiredman	bradbev: compile-files is true when you are compiling
00:20	bradbev	OK
00:20	hiredman	(def a (when-not compile-files (my-big-init)))
00:21	hiredman	dhaya: beat me
00:21	bradbev	now, the other thing that is screwy is (defn frame (JFrame. "foo")) also causes ant to break during compile
00:21	bradbev	that should be lazy evaled, right?
00:21	hiredman	uh
00:21	hiredman	no
00:21	hiredman	oh
00:21	hiredman	defn not def
00:21	bradbev	oh, crap - how did that even compile though?
00:21	hiredman	shrug
00:22	hiredman	well it did nae compile did it?
00:22	bradbev	heh, true
00:23	bradbev	ok, converting from a def to a defn & a call fixes the issue
00:24	bradbev	though it does leave the problem that defs are evaled at compile time & they may construct java objects
00:26	hiredman	that is what compile-files is for
00:27	hiredman	compile and load are kind of the same thing, compile just also outputs class files
00:27	bradbev	yeah, wrapping the def in (if (not compile-files)) works
00:28	bradbev	thanks for the help
00:28	dhaya	bradbev: (when-not might more idiomatic i think..
00:29	bradbev	dhaya: thanks - I didn't know about that (I did know unless isn't there :))
00:30	dhaya	I have no idea about unless. is that a CL thing?
00:31	hiredman	ruby has it
00:31	dhaya	ah..ok.
00:32	bradbev	CL has it also
01:06	wipewindows	which should I ask for as a christmas prsent, im a strange loop or GED?
01:11	cads	wipewindows, I'd just download some of godel's papers, buy some escher prints, and enjoy some pirated bach
01:13	cads	it's a lot of dumbed down philosophy and the author tries to get across how wonderful and strange our consciousness (his consciousness) is
02:48	dmiles	any DotLisp hackers in here atm?
02:50	dmiles	trying to figure out where (Hex/DecodeHexString text) comes from
04:11	AWizzArd	clojurebot: max people
04:11	clojurebot	max people is 116
10:22	rhickey	any contrib-ers out there? move to gc go ok?
10:24	Chousuke	is everything in contrib EPL now?
10:32	rhickey	Chousuke: yes
10:55	RSchulz	I just checked it out and built it without a hitch.
10:57	AWizzArd	rhickey: what again was the title of this book about concurrency in Java?
10:57	rhickey	Java Concurrency in Practice
10:57	AWizzArd	thx
10:58	duck1123	reading chapter 6.2.5
10:59	gnuvince	Wouldn't that be a section of chapter 6?
10:59	gnuvince	</anal>
11:08	kyleburton	/?
11:08	kyleburton	er, does there happen to be a way to know the name of the form being defined?
11:09	rhickey	kyleburton: for what to know?
11:09	kyleburton	well, I was toying with creating a log form
11:09	kyleburton	and it'd be nice to know the file name (if available), line number and fn name
11:09	rhickey	Chouser: what's the alternative?
11:09	kyleburton	so it could expand to including that in the log stmt
11:09	kyleburton	eg: (defn some-func [] (log-debug "foo"))
11:10	kyleburton	it'd be nice if that could expand into something like:
11:10	kyleburton	(defn some-func [] (log/log-debug "test.clj" 107 "some-func" "foo"))
11:10	wlr_	google code's clojure-contrib still has svn/trunk/CPL.txt
11:11	kyleburton	well, really w/the args wraped in a lambda so they dont get computed unless the levle is that high
11:11	kyleburton	kind of like __pretty_function__, __LINE__ and __FILE__
11:11	kyleburton	well, exactly like those
11:12	Chouser	rhickey: I don't suppose there's any way to display those rules on the "new issue" form?
11:13	duck1123	Chouser: where are these rules?
11:13	Chouser	duck1123: exactly.
11:14	rhickey	Chouser: I can pre-fill the description box with text, some of the rules are there
11:15	Chouser	ok. I don't have a good alternative. Maybe some firm policing will be sufficient.
11:16	Chouser	duck1123: rules: http://groups.google.com/group/clojure/browse_thread/thread/1a4fe97a957ec52a
11:18	rhickey	Chouser: ok, full set of rules now in the entry form
11:19	duck1123	now that the issue tracker is being used, should clojurebot announce new tickets?
11:19	Chouser	kyleburton: (defmacro log [msg] `(prn ~msg ~file))
11:20	rhickey	duck1123: there is a dev feed, just trying to get it set up the way I want
11:20	kyleburton	ok, file is good, is there a line and perhaps a top-level-form-name?
11:20	Chouser	kyleburton: looks like there's currently no similar way to get to the line number.
11:20	kyleburton	Chouser: thank you re: file
11:20	Chouser	kyleburton: but both are available as metadata of the var -- 'some-func' in your example.
11:21	kyleburton	Chouser: yes, but how can you get the name of the enclosing top level form so the macro can see it?
11:21	Chouser	...but I don't think the name of that var is available to the expression being evaluated for the var's value.
11:21	rhickey	Chouser: file isn't going to help there, as it's value at runtime will be nil
11:21	kyleburton	rhickey: even if you expand with ~file?
11:22	rhickey	i.e. a macro can use it, but to emit it doesn't help
11:22	kyleburton	rhickey: doens't that get resolved at compile...
11:22	Chouser	rhickey: sure, but in that macro I posted the compile-time value of file is inserted into the expression
11:22	rhickey	that's all this is for? nevermind
11:22	gnuvince	Does Java allow mutating final fields?
11:23	Chouser	gnuvince: don't think so. I think that's the point of them being final.
11:24	AWizzArd	I think Clojure declares a lot of stuff as final under the hood, to come to its performance.
11:25	gnuvince	Chouser: I wasn't sure what final meant for fields.
11:32	RSchulz	A final field in Java cannot be assigned, but the object to which it refers (if it's not primitive) but nothing prevents invoking mutating methods on the instance referred to by that field.
11:32	RSchulz	It's not at all like C++ const.
11:32	RSchulz	Oops. That came out mangled.
11:32	Chousuke	it's more like a const*
11:33	Chousuke	or is that *const? :P
11:33	RSchulz	You can't reassing a final field after initialization, which must happen by the time the constructors exit.
11:33	RSchulz	But you can call any method on the values in such fields.
11:33	RSchulz	Chousuke: Yes, it's like *const.
11:44	aperotte	Chouser: I figured out why I was getting different behavior when using (load-file ...) versus evaluating each form in the file
11:45	aperotte	Chouser: I traced it down to a function definition that used map, but was being used for side effects and the return value of the function wasn't being used for anything
11:46	aperotte	Chouser: I'm assuming that the map was evaluated lazily (?) when using (load-file) because it didn't need to print the result whereas at the repl it was forced because of the need to print (?)
11:50	Chouser	aperotte: ah, very good!
11:50	Chouser	thanks for bringing me up-to-date. That's likely to come up again.
11:51	aperotte	No problem, thanks for the help
11:51	aperotte	RSchultz: Thanks for your help in trying to figure this out as well.
11:57	Lau_of_DK	Good evening all
12:00	ericthorsen	I have a clojure resource in a netbeans module that is calling (clojure.core/require "a.properly.placed.namespace.file") which is referencing public java classes in the same module. The clojure file gets loaded but cannot see the java classes. Anyone have any insight as to how I might trouble shoot this?
12:02	rhickey	the require is for a .clj file? not compiled?
12:02	ericthorsen	rhickey: yes
12:03	rhickey	ericthorsen: you might have a much easier time if you compiled it
12:04	rhickey	it's probably related to classloader that loaded Clojure doesn't have access to that module?
12:06	ericthorsen	rhickey: yes...we are going down that path as well.
12:07	rhickey	ericthorsen: AOT is motivated in part by trying to remove issues related to fancy classloader hierarchies like NB and dynamic classloading, by getting rid of the latter.
12:25	rhickey	http://groups.google.com/group/clojure-dev - read-only via web/xml, will get all issue changes for clojure and contrib
12:32	rhickey	hrm, wiki edits go in svn revision stream...
12:34	RSchulz	aperotte: Sorry I missed that before. I'm glad you sorted out the problem. And thanks for letting us know what it was. It's something to keep in mind.
12:35	ffailla	I are trying to run the clojure.lang.Compile command from a command line, how do i export the clojure.compile.path system property on a bash shell
12:59	tomhickey	rhickey: i see the wiki edits in the revision list on the site, but not in my svn client
13:00	rhickey	tomhickey: you're probably just pulling trunk - the wiki is a sibling of trunk, not under it
13:01	tomhickey	rhickey: ah, i see
13:32	Chouser	success!
13:33	rhickey	Not really, as I need patches/bug-reports to go there, getting lost in group traffic
13:33	Lau_of_DK	Rich, it looks good, not scared :)
13:36	RSchulz	rhickey: You asked us to discuss issues on the list before submitting issues, which of course makes complete sense. If an question doesn't come to resolution there, is it reasonable to submit an issue?
13:36	RSchulz	Case in point: How to get (shutdown-agents) to work without explicitly calling it. The list thread didn't end up with a resolution.
13:37	rhickey	RSchulz: probably not, we should be able to resolve bug or desirable feature on the group
13:37	rhickey	As far as that one, I don't see why clojure should do something specific, you have shutdown-agents
13:37	kotarak	RSchulz: maybe the Repl could be modified to allow shutdown-hooks?
13:38	rhickey	but in any case, the issues list is not for advocacy
13:38	RSchulz	I'm not asking for Clojure to do something, but there's a gap right now. There was the idea to use daemon threads for agents, though.
13:41	rhickey	RSchulz: then people who set off their whole program to run in agents will complain their agent threads die, and why do they have to explicitly wait for them
13:43	kotarak	When the Repl receives the ^D it reads eof and stops. Maybe one can install some shutdown hooks, which are executed after the eof is received.
13:43	RSchulz	How would one create generic facilities that use agents behind the scenes without burdening the user of those facilitiees to use (shutdown-agents) before exiting?
13:43	RSchulz	rhickey: I don't understand what you're saying. My specific problem is that calling (shutdown-agents) in a JVM shutdown hook seems not to be working.
13:44	Chouser	RSchulz: when to shutdown background threads is an application-wide question, not something that can be answered in smaller pieces, it seems to me.
13:44	RSchulz	Right. And I'd like to make it work in a generic way: via JVM shutdown hooks. That seems eminently reasonable to me.
13:45	Chouser	RSchulz: what makes you think the JVM shutdown hooks will run before all the threads have quit?
13:45	rhickey	RSchulz: this is a pure Java problem - the agents just use the Executors framework
13:45	RSchulz	Eh? I want it to run as part of the JVM shutdown processing. That's what they're for, right?
13:45	rhickey	RSchulz: shutdown happens after all threads are done
13:46	RSchulz	So what's the problem? Why do I hang upon CTRL-D from the REPL unless I call (shutdown-agents) _from_ the REPL?
13:46	RSchulz	So it's a chicken-and-egg thing?
13:46	rhickey	ctrl-d works for me
13:46	RSchulz	rhickey: When you've started agents?
13:46	walters	the threads have to be daemon threads (see Thread.setDaemon)
13:46	RSchulz	Agents that _have_ been (await ...) -ed?
13:47	rhickey	RSchulz: there-s your problem - your awaiting and not geting your ctrl-d
13:47	RSchulz	Eh?
13:47	RSchulz	Every agent I start gets awaited. Then later on when I CTRL-D, it hangs.
13:47	rhickey	you're blocked in await and don't see eof
13:48	RSchulz	I'm _not_ blocked in await. It returns. Otherwise I wouldnt' get the next REPL prompt.
13:48	RSchulz	I can do much stuff after returning from await and then when I CTRL-D, it hangs.
13:49	rhickey	RSchulz: please write a small example program that demonstrates your problem. Debugging english descriptions is impossible
13:49	RSchulz	And do what with it?
13:49	RSchulz	Send it to the list?
13:49	RSchulz	The reason I'm here now is that that thread on the list didn't get any resolution...
13:50	rhickey	yeah, or paste here. You're saying you have a problem - help us replicate it. You didn't post code there either.
13:51	rhickey	can't replicate, can;t fix. Giving a verbal description puts the onus on others to write a test case to reproduce the problem
13:51	Chouser	RSchulz: is this clojure.lang.Repl, or some other Repl?
13:51	RSchulz	The Contrib REPL.
13:52	Chouser	clojure.lang.Repl does a System/exit after ^D, which doesn't hang on the agent pools.
13:55	AWizzArd	Can I find out the path in which my program was run? If yes, how?
14:00	Lau_of_DK	Onus.... :)
14:01	rhickey	Chouser: I wonder if this unifying patch still does that? http://groups.google.com/group/clojure/browse_frm/thread/2aeb7bdc789d5933#
14:02	RSchulz	OK. There it is (on the list).
14:04	Chouser	rhickey: that patch appears to remove the System/exit and not re-instate it anywhere. I'm not in a position to test it directly right now.
14:05	Chouser	I've got completely hangled classloaders at the moment.
14:05	Chouser	mangled
14:23	AWizzArd	Is there something like read-line for files, which returns a vector of strings (of the lines of that file)?
14:23	Chouser	(doc line-seq)
14:23	clojurebot	Returns the lines of text from rdr as a lazy sequence of strings. rdr must implement java.io.BufferedReader.; arglists ([rdr])
14:23	kotarak	There is line-seq.
14:24	AWizzArd	Okay, so that is a bit closer to what I meant, thanks
14:25	AWizzArd	omg, I just saw http://www.roseindia.net/java/beginners/java-read-file-line-by-line.shtml
14:25	AWizzArd	why not just say (map function (lines "myfile.txt")) ?
14:26	AWizzArd	4x new in that file, uh!!
14:26	AWizzArd	"new"
14:26	Chouser	to be fair, a couple of those are still needed with line-seq
14:27	Chouser	only with duck-streams to we start to rise above
14:27	walters	that DataInputStream is unnecessary, you only need FileReader and BufferedReader
14:28	walters	(i'm not defending the bewildering lack of File.open() in the JDK, but it's not quite that bad)
14:30	AWizzArd	I think the easiest really is to use the ds/reader + line-seq.
14:30	AWizzArd	But ds/reader is not lazy, right? So it will read the whole file, may it be 50 bytes or 3 GB, yes?
14:34	Chouser	no, ds/reader just creates an appropriate java.io object, it doesn't actually read anything.
14:35	AWizzArd	okay, and line-seq itself is lazy
14:35	AWizzArd	so if I just want the first 100 lines out of 21 millions it would take +/- as much time as if the file would only have these first 100 lines.
14:37	rhickey	Chouser: nice post to code with line number in google code!
14:37	rhickey	very useful
14:38	Chouser	I've been wanting to do that, but sf.net was just too slow to be useful.
14:39	Chouser	the rev number is in there too, so reading that thread a few weeks from now it should still make sense.
14:39	rhickey	saw that, very nice
14:42	rhickey	code browsing seems very peppy
14:45	Lau_of_DK	rhickey: That "issue tracker" doesnt really seem to be the right tool for the job ?
14:46	rhickey	Lau_of_DK: how so?
14:46	RSchulz	Is there a way to get GC to colorize .clj files?
14:46	Lau_of_DK	rhickey: It doesnt provide a very good overview I think. And when reading on "pretty printing" for instance, next to no info is providing in the underlying 3 links.
14:47	kotarak	At least the template chooser could be more prominent. (And also marked as necessary for the type of issue)
14:58	hiredman	so clojure svn is in google code now?
14:58	Chouser	hiredman: yes
14:58	hiredman	clojurebot: svn is svn checkout http://clojure.googlecode.com/svn/trunk/ clojure-read-only
14:58	clojurebot	You don't have to tell me twice.
14:59	Lau_of_DK	Chouser: Have we switched away from Sourceforge to Googlecode?
14:59	Chouser	yes
14:59	Lau_of_DK	For what reason ?
15:00	hiredman	sf is :(
15:00	Chouser	more features, better response time
15:01	danm_	google code sure is faster
15:02	Lau_of_DK	Chouser: Am I to understand that we yet again missed a golden opportunity to switch to Git ? :)
15:02	Chouser	nope. switching to git is still a dead subject (imo) until Rich brings it up.
15:03	Lau_of_DK	Chouser: k
15:04	hiredman	clojurebot: relocate is svn switch --relocate file:/$PWD http://clojure.googlecode.com/svn/
15:04	clojurebot	c'est bon!
15:04	jimm	The download link on clojure.org still points to Subversion. Is that intended?
15:05	Chouser	that's the only place to get a .zip for now, I think.
15:05	rhickey	jimm: that's where the download is until the next release
15:05	jimm	rhickey: thank you
15:05	jimm	I see, the SVN link has been updated to google code
15:06	hiredman	svn rev 1162
15:07	clojurebot	svn rev 1162; EPL in header
15:07	clojurebot	svn rev 1168; Edited wiki page through web user interface.
15:07	clojurebot	svn rev 1169; Edited wiki page through web user interface.
15:07	clojurebot	svn rev 1170; Edited wiki page through web user interface.
15:07	clojurebot	svn rev 1171; Edited wiki page through web user interface.
15:07	clojurebot	svn rev 1172; Edited wiki page through web user interface.
15:07	hiredman	eeep
15:09	rhickey	I'll start putting comments on wiki edits since they're going in svn
15:11	hiredman	maybe I should filter wiki edits out?
15:12	Chouser	hiredman: it might be a bit noisy for a couple days, but I wouldn't be surprised if we appreciate the notification after a week or so
15:13	Chouser	that's very interesting, though -- the wiki is stored in the projects own svn repo.
15:13	hiredman	it's cute
15:14	hiredman	gah, that svn relocate deal doesn't really work
15:17	clojurebot	svn rev 1168; Edited wiki page through web user interface.
15:17	clojurebot	svn rev 1169; Edited wiki page through web user interface.
15:17	clojurebot	svn rev 1170; Edited wiki page through web user interface.
15:17	clojurebot	svn rev 1171; Edited wiki page through web user interface.
15:17	clojurebot	svn rev 1172; Edited wiki page through web user interface.
15:17	hiredman	clojurebot: stop that
15:17	clojurebot	I don't understand.
15:38	holmak	Apparently it is not acceptable to use the #() anonymous function form inside (-> ...) -- is this expected?
15:38	kotarak	holmak: you have to take care (-> x (#(do-something %)))
15:39	holmak	ah
15:39	Chouser	hm.
15:39	holmak	I guess -> was interacting poorly with the #() macro.
15:40	Chouser	indeed, the item to the left of #() is used as the name of the anonymous function
15:40	holmak	I thought since #(...) makes a function, -> ought to treat it as a non-list, and turn it into (#(...) arg)
15:40	holmak	That's obviously not what happens, given the macro expansions
15:42	Chouser	(-> foo #(+ % 2) (apply [3])) ==> 5
15:42	Chouser	-> is easy to abuse.
15:42	holmak	I will use caution, then.
15:42	Chouser	(-> [i 3] (dotimes (prn i)))
15:42	hiredman	cute
15:43	holmak	You're making it look downright dangerous
15:43	holmak	"-> considered harmful"
15:43	kotarak	bah, -> is cool. :)
15:43	Chouser	well, just don't use it in circumstances where it makes things harder to read.
15:44	kotarak	But it should really work as in: (-> 5 #(inc %))...
15:44	Chouser	I would suggest both my above examples fall in the "don't you dare" category.
15:44	hiredman	cool like riding a motorcycle with no helmet
15:44	kotarak	after the "here be dragons" sign
15:45	holmak	I'm thinking I should find another way of writing the section of code.
15:46	Chouser	-> is brilliant for expressions like: (-> "tmp.txt" File. FileReader. BufferedReader. line-seq)
15:47	Chousuke	I see it as a generalised ..
15:47	hiredman	yes
15:47	kotarak	or: (-> (var reduce) meta :ns ns-name name)
15:47	kotarak	very handy indeed
15:47	holmak	My problem is that (let [dbl #(* 2 %)] (-> 42 dbl)) is not the same as (-> 42 #(* 2 %))
15:48	kotarak	(-> 42 (* 2)) ?
15:48	Chousuke	holmak: the reason for that is simple, though
15:48	Chousuke	since #(* 2 %) expands to a list
15:48	holmak	Oh, I understand why, but substitution like that feels like it should work.
15:49	Chousuke	I don't see a simple way to make it work though.
15:49	hiredman	holmak: http://www.thelastcitadel.com/blag/pipe_macro
15:49	Chousuke	besides some special handling for #() :/
15:49	holmak	The other thing is that the error was extremely unhelpful.
15:49	hiredman	I think that maybe an icky macro
15:50	holmak	That's the bigger problem: java.lang.ClassCastException: java.lang.Integer cannot be cast to clojure.lang.ISeq
15:50	kotarak	I think the problem is, that #() is expanded by the reader.
15:51	holmak	Maybe the documentation should have a warning about using #() with -> ?
15:53	holmak	hiredman: That pipe macro is interesting.
15:53	hiredman	"# signals a reader macro, there be dragons"
15:53	RSchulz	holmak: Clojure's error diagnostics are meant as a form of aversive therapy to accelerate your learning and deter incorrect ussage.
15:53	holmak	"Don't get errors, because they will be completely and utterly unhelpful" ?
15:53	holmak	:D
15:55	RSchulz	Yeah. something like that.
15:55	Chouser	what should the error be, in that case, and how would the code detect it?
15:56	holmak	I have no idea, there's really nothing that can be done, probably. I was just really puzzled.
15:56	hiredman	"I've noticed you are using ->, I bet you think you're clever don't you? EXCEPTION!"
15:57	RSchulz	I think, very generally speaking, the extreme parsimony of a language like Clojure is an impediment to error diagnostics. In a language like Java which is so verbose, there are more (in some sense) redundant queues that the compiler / interpreter can use to clarify their error messages.
15:57	holmak	Clearly what is needed is an ExcessiveClevernessException
15:57	RSchulz	"My master told me I was clever. I thought it was a complement. He meant it as an insult."
15:58	RSchulz	(Or "compliment," as the case may be...)
15:58	holmak	RShulz: I agree completely. It's kind of hard to write an actual invalid form in Clojure. You just end up writing something valid, but nonsensical.
16:03	lisppaste8	kotarak pasted "Voodoo ->?" at http://paste.lisp.org/display/72311
16:05	hiredman	it's a recursive macro, I guess
16:05	RSchulz	holmak: Or something the error of which is detected a distant point of execution.
16:06	kotarak	"Debugging code is harder than programming it. So if you code as clever as you can - by definition - you wont be able to debug it." (Free after Kernighan? maybe?)
16:09	hiredman	which is why you need a repl
16:09	kotarak	Earnestly: can we use fn* as marker for #()? One isn't supposed to use it anyway.
16:10	RSchulz	Should we not avoid using undocumented forms?
16:12	kotarak	We don't use it. Just as a marker. (but in the end this is still a bad idea...)
16:23	drewr	What is the value of ns supposed to be if I've declared (ns foo.bar) right before referencing it?
16:23	drewr	I keep getting clojure.core.
16:23	drewr	I'd rather get foo.bar.
16:25	hiredman	I get foo.bar
16:25	Chouser	drewr: in the next top-level form, ns should be foo.bar
16:26	hiredman	hiredman.clojurebot=> (do (ns foo.bar) (prn ns) (in-ns 'hiredman.clojurebot))
16:26	hiredman	#<Namespace foo.bar>
16:26	hiredman	#<Namespace hiredman.clojurebot>
16:26	hiredman	hiredman.clojurebot=>
16:28	drewr	It's inside of a defn and a let.
16:29	hiredman	juggling namespaces inside a defn does not sound like a good idea
16:29	hiredman	and you'll never get me to admit that I do it
16:30	RSchulz	Not an open-source kinda' guy?
16:31	hiredman	just in denial
16:33	danlarkin	drewr: the ns macro is designed to be used once per file at the top
16:33	danlarkin	not in a function or a let
16:33	drewr	I see. ns is the current namespace of the caller of a fn.
16:34	RSchulz	Open source kind of undermines the plausibility of one's denials...
16:34	hiredman	RSchulz: I am in denial about that
16:34	drewr	How can I get to the enclosing namespace of a fn?
16:35	RSchulz	^#'find-doc
16:35	RSchulz	(Using find-doc as an example)
16:36	RSchulz	drewr: To be explicit, the namespace is an element of the metadata of the Var holding the entity in question.
16:36	drewr	OK, it's in the meta, but then I need to know the name of the function. :-/
16:36	drewr	Is there no way to say "give me the namespace that owns the fn I'm in?"
16:37	RSchulz	It's like buying a household appliance that will tell you the address of the house in which you've installed it.
16:37	RSchulz	(which is my clever way of saying that's static information.)
16:37	alphazero	hi all.
16:38	Chouser	drewr: you want this info at runtime?
16:38	alphazero	I'm trying to run ants.clj and am getting Exception in thread "main" java.lang.Exception: Unable to resolve symbol: setColor in this context (ants.clj:234)
16:38	drewr	Chouser: Yep.
16:38	alphazero	(defn fill-cell [#^Graphics g x y c]
16:38	alphazero	(doto g
16:38	alphazero	(setColor c)
16:38	alphazero	(fillRect (* x scale) (* y scale) scale scale)))
16:39	Chouser	alphazero: try .setColor and .fillRect (note the dots)
16:39	alphazero	running from svn 1162
16:39	hiredman	old doto syntax
16:39	alphazero	Chouser: Thanks, I'll do that.
16:43	rhickey	alphazero: the ants.clj on the Google Group has that change already
16:43	Chouser	heh. didn't recognize the code.
16:43	rhickey	http://clojure.googlegroups.com/web/ants.clj
16:43	alphazero	rhickey: thanks! that saves time!
16:45	alphazero	excuse the newb q, but typing clj ants.clj puts up the frame and the blue square but then nothing.
16:46	alphazero	nevermind, just saw the (comment ..)
16:50	alphazero	hmm. changed the /Users/rich/.. to load local file ./ants.clj. and have uncommented the demo block
16:50	alphazero	now it simply keeps flashing the frame, my dual cores going at ~ 60% each. no ants :(
16:52	alphazero	this is the beginning of a very long stack trace:
16:52	alphazero	Exception in thread "main" java.lang.OutOfMemoryError: PermGen space (ants.clj:215)
16:52	alphazero	at clojure.lang.Compiler.analyzeSeq(Compiler.java:4113)
16:52	alphazero	at clojure.lang.Compiler.analyze(Compiler.java:3935)
16:52	alphazero	at clojure.lang.Compiler.analyzeSeq(Compiler.java:4094)
16:52	alphazero	at clojure.lang.Compiler.analyze(Compiler.java:3935)
16:52	alphazero	at clojure.lang.Compiler.analyze(Compiler.java:3908)
16:52	alphazero	at clojure.lang.Compiler$NewExpr$Parser.parse(Compiler.java:2150)
16:52	alphazero	at clojure.lang.Compiler.analyzeSeq(Compiler.java:4106)
16:52	alphazero	Running on Mac OS X 10.4 with 1132MB of free mem.
16:52	Chousuke	alphazero: next time, please use pastebin :)
16:53	Chousuke	lisppaste8: url
16:53	lisppaste8	To use the lisppaste bot, visit http://paste.lisp.org/new/clojure and enter your paste.
16:53	Chousuke	there
16:53	alphazero	Chousuke: Sorry, will do.
16:54	lisppaste8	alphazero pasted "stack trace ants.clj svn 1162 mac os x 10.4 std clj shell script" at http://paste.lisp.org/display/72318
16:54	Chousuke	alphazero: anyway; the default java heap size is limited, you might want to try running java with the -server option
16:54	alphazero	Chousuke: k, let me try that.
16:54	RSchulz	Chousuke: I don't know about Java on the Mac, but I don't think -server will change the heap allocation. That'x -XmxNNN
16:55	Chousuke	IIRC -server raises it to 128MB
16:55	Chousuke	from 64 or something
16:55	RSchulz	Really? I didn't know that.
16:56	walters	permgen space is special
16:56	rsynnott	'-server' is a very poorly named option
16:56	walters	if you search for "java permgen" you'll get a lot of hits, http://blogs.sun.com/fkieviet/entry/classloader_leaks_the_dreaded_java is one
16:57	Chousuke	RSchulz: "There is not a distinct server VM for Mac OS X. Although you may use the -server flag when invoking java, it does not start up a different VM, instead it starts the client VM that has been tuned for use in a server environment." and heap size is included in the tuned parameters :)
16:57	walters	basically it's the area where class code is loaded; in most GCs it's a fixed size, and you need special options to enable collecting it
16:57	RSchulz	Great. Thanks.
16:57	RSchulz	I knew they were integrated, but the default heap size adjustment had escaped my notice.
16:59	alphazero	Well, -server seemed to have pushed cpu util to ~80% but basically same behavior. not a single ant even showed up, just flashing the screen with a blue box.
17:02	Chousuke	hmm
17:03	rhickey	alphazero: the code in the comments is not supposed to be uncommented, then loaded (will recursively load itself if you do that. It's meant for a demo - load the file (which the first commented line does), then eval the other lines
17:03	rhickey	it's not an executable script
17:04	Chousuke	apparently I can't wget stuff from google code easily :/
17:04	rsynnott	alphazero: I think -server is far more aggressive about JITing, which may help to explain the extra processor usage
17:04	Chousuke	the file link takes me to some stupid clickthrough page :P
17:04	alphazero	rhickey: so how do I run ants.clj? from Repl?
17:04	Chousuke	alphazero: emacs & slime works very well :)
17:05	Chousuke	you can eval the entire file and then just eval the code inside the comment separately
17:05	alphazero	Chousuke: damn it, I'm drawing the line at (((((()))))) .. ;)
17:05	rhickey	alphazero: I load it into emacs, then run each line in the comments one by one, for demo
17:06	rhickey	but your problem definitely is that it is loading itself infinitely recursively
17:06	rhickey	blowing permgen on compilation
17:06	alphazero	rhickey: well, i'm not setup for that yet. so no way to run this simply from Repl?
17:07	Chouser	alphazero: yes
17:07	Chouser	java -cp clojure.jar clojure.lang.Repl ants.clj
17:07	Chouser	then paste each of the lines from the comment section into the repl, one by one
17:08	Chousuke	you really should consider using emacs. it's worth it just for slime :P
17:08	Chouser	middle-click-paste on X-windows makes this a breeze, but I imagine MacOS will let you do what you need to with Command-V
17:09	triddell	alphazero: if the REPL is already started the first line in the comments is (load-file ...
17:09	triddell	just point to your ants.clj
17:09	triddell	then run the other lines in comments
17:09	alphazero	Chouser: that's what I have been doing. sorry being dense. + installed acquamacs and went through the whole clojure-mode thing. but the whole C-c (type type type type) thing just to do simple stuff. So much fun ..
17:12	alphazero	Hey, success! Thank ya'll for your patience.
17:12	Chouser	Chousuke: I'm glad you find slime worth while. I'll refrain from saying anything else.
17:14	Chousuke	heh
17:14	Chousuke	well I can handle editing in emacs with viper :P
17:15	Chousuke	though I do use some of the less offensive emacs shortcuts too.
17:15	Chousuke	having caps lock as control really help
17:15	Chousuke	s
17:17	Chouser	I guess the only other thing I'll say about emacs here is that I hope people's advocacy of emacs+slime+swank and of using the latest svn (which also then requires svn, ant, javac) doesn't turn people off
17:17	Chouser	...when all they really need is their favorite text editor, clojure.jar, and a JVM.
17:17	Chouser	at least to get started.
17:17	Chousuke	well, I guess we can start recommending 1.0 after it's out
17:18	danm_	although, writing lisp in an editor which doesn't speak parens is somewhat frustrating
17:18	Chouser	Chousuke: only if there's a perfectly-matched slime setup for 1.0 available, right?
17:18	Chousuke	well, there is that clojurebox thing
17:18	Chouser	for Windows
17:19	Chouser	...and still you're going to spend time learning emacs instead of clojure
17:20	Chousuke	I suppose.
17:20	Chousuke	now if I could figure out why my aquamacs insists on opening two windows on startup I'd be happy.
17:20	hiredman	clojurebot: emacs?
17:20	clojurebot	but I like using notepad++!
17:21	hiredman	actaully I did a few euler problems in notepad++
17:23	gnuvince_	You wrote the solution in notepad++ or you actually used notepad++ to solve them?
17:25	hiredman	a solution using clojure in notepad++
17:25	Chouser	now, writing notepad++ using a solution in clojure, why that'd be something.
17:26	gnuvince_	;)
18:12	triddell	Using a java library class I've slurped up some file contents into a java.util.Hashmap. Is this object a seq? Can I use standard clojure functions on a java Hashap?
18:12	triddell	this was created: #=(java.util.HashMap. {"key1" "value1", "key2" "value2"})
18:14	triddell	if this object is represented by config how would I access the values, etc.?
18:15	rhickey	triddell: if you seq it you will get a seq of Map.Entry, but loys of things work on them, like, key, val, and destructuring:
18:15	rhickey	(map (fn [[k v]] [k v]) #=(java.util.HashMap. {"key1" "value1", "key2" "value2"}))
18:15	rhickey	(["key1" "value1"] ["key2" "value2"])
18:17	rhickey	also:
18:17	rhickey	user=> (for [[k v] #=(java.util.HashMap. {"key1" "value1", "key2" "value2"})] [k v])
18:17	rhickey	(["key1" "value1"] ["key2" "value2"])
18:17	rhickey	user=> (keys #=(java.util.HashMap. {"key1" "value1", "key2" "value2"}))
18:17	rhickey	("key1" "key2")
18:17	rhickey	etc
18:18	triddell	thanks rich!
18:18	meredydd	Is #= new?
18:18	fyuryu	triddell: if you want to turn it into a persistent hash map: (into {} your-hashmap)
18:19	rhickey	meredydd: don't use #= in your code
18:19	fyuryu	triddell: less noise on the repl
18:19	meredydd	You just used it in a fragment there. What does it do?
18:20	triddell	fyuryu: I'll try that
18:20	rhickey	meredydd: nothing that (java.util.HashMap. {"key1" "value1", "key2" "value2"}) doesn't, I just grabbed it from his output
18:21	rhickey	it's a print-dup format for serialization - you won't see them at the repl at all soon
18:23	meredydd	ah...a quick google suggests you're doing something with generic-ising the print functions
19:55	clojurebot	svn rev 1173; updated readme with run and build lines
20:04	triddell	another simple question... I have a map which I can read a key from like (get YAML-config "context-root")... and this is true: (contains? YAML-config "context-root")... but why cant I do this (:context-root YAML-config)
20:06	Chouser	the string "context-root" is different from the keyword :context-root
20:07	triddell	right, I'm trying to understand the "maps of their keys" piece
20:07	triddell	I mean functions of their keys
20:07	Chouser	oh, that's just (YAML-config "context-root")
20:07	phf	triddell: functions of their keys should be opposed order
20:07	phf	what Chouser said
20:09	triddell	ah, ok, thanks
20:23	rhickey	New release: http://clojure.googlecode.com/files/clojure_20081217.zip (for your friends that aren't on SVN yet)
20:24	Chousuke	hooray. now the release version will actually work with most of the examples in the wiki and other sources :)
20:24	rhickey	I could use some help going over the docs/examples looking for inaccuracies or anachronisms
20:24	rhickey	e.g. trying every example
20:35	qebab	Hi. I've decided to spend some time during christmas picking up clojure. Could anyone tell me something about how it'd feel for someone who usually programs python but hacks scheme and C on the side? :)
20:36	hiredman	of those three it is most like scheme
20:36	Chouser	qebab: it feels like a fresh sea breeze on a stifling hot day
20:38	qebab	hiredman: unsurprising, since it's the only lisp in that list :) I noticed an example on clojure.org that seems to use pattern-matching. how does that relate to pattern matching in languages like haskell?
20:38	Chouser	Clojure does not have haskell-like pattern matching, but it does have handy destructuring.
20:38	qebab	Chouser: that is good to hear, it's been a long half year with 3 very boring classes, so I need something to motivate myself for further hacking next year
20:39	qebab	aha, so that's what it is
20:39	phf	qebab: there's also dispatch on the number of arguments
20:39	qebab	does it work on all datastructures that have builtin syntax?
20:39	phf	but i think that's mostly a mapping to java world
20:39	Chouser	qebab: yes
20:39	qebab	cool
20:40	hiredman	clojure has dispatching on any function of the arguments to a function
20:40	Chouser	qebab: if you don't mind the format, watch one of the screencasts -- probably the one on sequences
20:40	Chouser	that'll get you motivated.
20:40	qebab	my first impression is that this is common-lisp with a whole bunch of bad design choices removed, and lots of good ideas added
20:41	Chousuke	that's not a bad first impression I guess.
20:41	Chousuke	not optimal either though.
20:41	Chouser	yeah, it doesn't feel like common lisp to me.
20:42	qebab	well, I prefer scheme to common lisp, but find the latter more practical... I'm hoping that clojure will be both practical and nice :)
20:42	Chousuke	the java interop is perhaps underappreciated. a lot of clojure "Just Works" with java.
20:43	qebab	yeah, looks like a very nice feature
20:43	hiredman	which is really nice
20:45	qebab	there are tons of cool examples, that's for sure
20:46	qebab	is there a handy documentation searching function?
20:46	Chousuke	(doc find-doc)
20:46	clojurebot	Prints documentation for any var whose documentation or name contains a match for re-string-or-pattern; arglists ([re-string-or-pattern])
20:47	qebab	something like help() without parameters does in python (Let's you search in docstrings and module documentation and things like that)
20:47	qebab	oh, neat
20:47	qebab	thanks
20:47	Chousuke	it's not very easily browseable though.
20:48	hiredman	bookmark clojure.org/api
20:48	Chousuke	it should be pretty straightforward to use find-doc as a basis for some kind of function that uses clojure.inspector for browsing the results.
20:49	qebab	this works nicely for now, I'm basically just working out what the functions I'm used to from scheme/cl are called here
20:50	Chousuke	the wikibook tutorials and tips section has something about that.
20:50	Chousuke	the book is in pretty bad shape still, but hopefully it will improve :P
20:51	hiredman	clojurebot: map?
20:51	clojurebot	map is LAZY
20:53	phf	which allows for some ... interesting debugging situations in combination with local bindings
20:53	qebab	ohh, map is lazy :o
20:54	Chousuke	qebab: most of the seq-consuming functions in clojure are
20:54	Chousuke	be aware of this when dealing with functions that have side-effects :)
20:55	qebab	Chousuke: I've programmed a fair bit of haskell (Of course, there you have the type-system babysitter, but still...), so I should do fine on that count :)
20:55	Chousuke	to avoid mapping #(println "hello" %) over a collection and wondering why it does nothing
20:55	qebab	gah
20:55	qebab	I just managed to pour coffee on my desk
20:58	RSchulz	Pouring coffee on your desk is a challenge, so you should feel proud!
20:59	hiredman	clojurebot: qebab likes haskell
20:59	clojurebot	excusez-moi
20:59	hiredman	damn it
21:00	hiredman	hmmm
21:00	qebab	clojurebot: help
21:00	clojurebot	I don't understand.
21:00	qebab	what can it do?
21:01	hiredman	what would you say if I told you qebab likes haskell?
21:01	hiredman	clojurebot: what would you say if I told you qebab likes haskell?
21:01	clojurebot	Yo dawg, I heard you like Haskell, so I put a lazy thunk inside a lazy thunk so you don't have to compute while you compute.
21:01	hiredman	qebab: not much
21:01	qebab	okay
21:02	hiredman	does docs
21:02	hiredman	(doc trampoline)
21:02	clojurebot	trampoline can be used to convert algorithms requiring mutual recursion without stack consumption. Calls f with supplied args, if any. If f returns a fn, calls that fn with no arguments, and continues to repeat, until the return value is not a fn, then returns that non-fn value. Note that if you want to return a fn as a final value, you must wrap it in some data structure and unpack it after trampoline returns
21:02	qebab	that's useful
21:03	qebab	oh, you can optionally name lambdas so they can recurse?
21:03	hiredman	yes
21:04	hiredman	(fn a [x] (a x))
21:04	qebab	that's pretty awesome
21:27	RSchulz	qebab: Whether a fn / lambda has a name or not (is the binding of a Var) changes nothing about how or where it may be used / invoked in Clojure.
21:48	triddell	what's the best way to recode a switch statement in clojure/lisp?
21:48	durka	look at cond
21:49	triddell	got it, thx
23:00	timothypratley	is there a way to search for a value in a vector... like (contains? \e "efg") <-- but that wont work because it works on maps
23:01	Chouser	(some #{:c} [:a :b :c :d :e])
23:05	timothypratley	ah... so
23:05	timothypratley	user=> (some #(= %1 \e) "efg")
23:05	timothypratley	true
23:05	timothypratley	user=> (some #(= %1 \e) "afg")
23:05	timothypratley	nil
23:05	timothypratley	thanks
23:07	Chouser	or (some #{\f} "efg")
23:08	timothypratley	even better!
23:54	triddell	Anybody here use the html generation features of Compojure?
23:56	triddell	It's based on nested vector syntax and I have a need to create some repeating blocks of html/xml.... but I need to open a new file for each repeated block... hopefully that is possible.
23:58	triddell	Would one typically use a for comprehension to process a list of files?
23:59	dhaya	triddell: side effects are typically done with doseq