#clojure – 2009-06-05

2009-06-05

03:57	alinp	hi
03:57	alinp	is it possible in clojure to do something like that: (def x (eval "(+ 1 2)"))
03:57	alinp	?
03:58	alinp	I'm sure this is not the function that needs to be used
03:58	alinp	but is there a function to be used for this purpose ?
03:58	opqdonut	you're not fine with (def x (eval '(+ 1 2))) ?
03:58	opqdonut	you could always invoke the reader
03:58	opqdonut	i dunno if it's exposed
03:59	opqdonut	ah, read
04:00	slashus2	,(eval (read-string "(+ 1 2)"))
04:00	clojurebot	DENIED
04:00	slashus2	That is how you would do it alinp
04:00	opqdonut	,(read-string "(+ 1 2)")
04:00	clojurebot	(+ 1 2)
04:00	opqdonut	yeah
04:01	alinp	read-string, thanks slashus2 & opqdonut
04:37	jdz	did anydoby mention that eval is evil?
04:38	opqdonut	of course it isn't :)
04:39	slashus2	It would be bad if it was.
04:39	jdz	how so?
04:39	jdz	eval is the most evil function
04:39	jdz	i'm yet to come across a case when i need it...
04:40	opqdonut	not all metaprogramming can be done just with macros
04:42	jdz	i'd like to see an example
04:44	slashus2	A really bad example would be if you wanted to use a macro in a function, and you want to expand the & more arguments. (eval `(amacro ~@more)) I don't know..
04:44	opqdonut	well i have a macro that interprets a series of sexps into a complex data structure describing a computation
04:45	opqdonut	a "dsl" if you will
04:45	opqdonut	but i still want to invoke lisp deep within this sub-language
04:45	opqdonut	so the macro evals some parts
04:47	slashus2	jdz: I think hiredman used it in clojurebot to evaluate form in cond-eval
04:48	jdz	slashus2: if you want to evaluate Clojure code, eval is what you use...
04:49	jdz	opqdonut: i'm still not convinced.
04:49	slashus2	yep
05:55	yason	Hmmm, what's the idiomatic way to turn a sequence into a new sequence that contain N-sized chunks of the original sequence?
06:00	lenst	(doc partition)
06:00	clojurebot	"([n coll] [n step coll]); Returns a lazy sequence of lists of n items each, at offsets step apart. If step is not supplied, defaults to n, i.e. the partitions do not overlap."
06:10	opqdonut	gah, just realised why the eval command is , in clojurebot
06:11	yason	ah
06:11	yason	I've seen it before
06:11	yason	thanks
09:06	bstephenson	can anyone online answer a weird clojure.contrib.sql problem we are seeing? Otherwise, I will post the question to the newsgroup.
09:15	eevar2	hard to tell if you don't ask your question..
09:32	bstephenson	sorry, was hoping the SQL author was online....here is our problem:
09:33	bstephenson	we try to use the insert-values function to insert a record into a PostgreSQL database
09:33	bstephenson	turns out eh record was violating a foreign key constraint by referencing an account that was not in the accounts table
09:33	bstephenson	we got this error back from REPL:
09:33	bstephenson	<CompilerException java.lang.IllegalArgumentException: No matching
09:33	bstephenson	method found: println for class java.io.OutputStreamWriter
09:33	bstephenson	(NO_SOURCE_FILE:0)>
09:34	bstephenson	insterad of a JDBC error indicating that FK was violated (which we usually do)
09:34	bstephenson	both ID fields are UUID fields
09:34	bstephenson	once we put in the account intot he accounts table, the record we were trying to write went into the db without a hitch
09:34	bstephenson	wondering why we did not see a JDBC error when the problem was an FK violation?
09:39	bstephenson	ahh, sorry channel, we found the problem. Related to our editor, not clojure.contrib.sql
10:23	ezyang	Hey all; what's the difference between using (if (seq l)) and just directly checking if it's null?
10:25	Chouser	ezyang: an empty collection is logical true
10:25	Chouser	,(let [c []] (if (seq c) "something" "nothing"))
10:25	clojurebot	"nothing"
10:25	Chouser	,(let [c []] (if c "something" "nothing"))
10:25	clojurebot	"something"
10:25	ezyang	Oh. That's different from Scheme
10:25	ezyang	I thought an empty list was nil
10:25	Chouser	no
10:26	ozzilee	,(seq [])
10:26	clojurebot	nil
10:26	Chouser	,(let [c (list)] (if (seq c) "something" "nothing"))
10:26	jdz	ezyang: in scheme empty list is logical true, no?
10:26	clojurebot	"nothing"
10:26	Chouser	,(let [c (list)] (if c "something" "nothing"))
10:26	clojurebot	"something"
10:26	ezyang	jdz: well, you do something like (null? list)
10:27	jdz	ezyang: same here, you do (seq lst)
10:27	ezyang	OK.
10:28	Chouser	in fact the idiomatic way to test for a non-empty collection is to use (seq x) in a boolean context.
10:28	Chouser	instead of (if (not (empty? coll)) ...), you say (if (seq coll) ...)
10:28	ezyang	Why is that the case?
10:29	jdz	because saying "something" sounds better than "not nothing"?
10:30	jdz	easier on the brain at least
10:30	ezyang	jdz: Oh, ok.
10:30	ezyang	I would normally use null? and then define the base case, and then do the regular stuff in the else
10:32	ezyang	Totally unrelated question: is there any way to dynamically update the REPL code
10:32	ezyang	without quitting the repl, recompiling, and then running again
10:32	ezyang	s/update the REPL code/update the code while you're in the repl/
10:32	jdz	def?
10:33	jdz	well, how did you get the code in the repl in the first place?
10:33	ezyang	jdz: I changed my namespace
10:33	ezyang	And then the classpath found it
10:33	ezyang	The idea is I open the repl to debug some clj files, and then I edit those files
10:34	jdz	i have not tried, but maybe remove-ns + require will do
10:34	ezyang	I guess I'm being kind of unreasonable here
10:34	ozzilee	ezyang: (require 'my-ns :reload-all)
10:34	jdz	well, most people use some kind of a developement environment, like emacs + slime or netbeans or something
10:35	ezyang	I spent last afternoon trying to get VimClojure to work
10:35	ezyang	I think that I'm stuck on some special mvn behavior
10:36	jdz	serves you well for wanting to use vi[m] for lisp developmement evil grin
10:37	ezyang	I think it's kind of unreasonable to learn a new text editor (emacs) just to develop in it.
10:37	ezyang	s/in it/in clojure/
10:37	jdz	well it's reasonable for a lisp developer to want to redefine stuff on the fly without reloading the world
10:37	jdz	like redefining functions, for instance
10:37	gnuvince	There's NetBeans, Eclipse, IntelliJ that are coming up with plugins for Clojure if you prefer.
10:38	gnuvince	Emacs is just so tightly knit with Lisp and its community that it's no wonder that the majority of Lispers prefer it.
10:38	Chouser	ezyang: I agree
10:41	ezyang	gnuvince: I totally understand why emacs is +1 for lisp development
10:42	ezyang	And it's also a text editor that is worth learning
10:42	Chouser	is it? is it really?
10:42	ezyang	I think you should be proficient in both vim and emacs :-)
10:43	gnuvince	ezyang: thankfully, I am :)
10:43	gnuvince	I use vim at work for Django work, and Emacs at home for Clojure and Haskell
10:43	gnuvince	And I'm pretty happy about my situation
10:46	piyo	ezyang: have you tried technomancy's clojure+emacs guide? http://technomancy.us/126
10:46	ezyang	Not yet
10:46	piyo	It cleared up a number of problems for me
11:18	cemerick	we use netbeans + enclojure to very good effect, FWIW
11:19	cemerick	the debugger isn't there yet, but I'll bet it's not there for slime, either
11:19	Chouser	the size of all these tools scares me. :-/
11:20	cemerick	If you can understand the whole thing top to bottom, chances are it doesn't do much for you. ;-)
11:20	Chouser	wow
11:20	cemerick	yeah, I always get that kind of reaction when talking to other programmers
11:21	cemerick	abstractions are good, they give you leverage.
11:21	Chouser	But I don't need to understand how it all works, I just need to understand how to use it. That's sufficiently scary for emacs, netbeans, eclipse...
11:22	cemerick	huh. I've always found NB very friendly. Somewhat more so than eclipse, and quite clearly more approachable than emacs.
11:22	aravind	Chouser: so.. what do you use for development?
11:22	Chouser	I'm always afraid to say. People (Rich included) mock me.
11:22	hiredman	notepad++
11:22	Chouser	text editor. repl.
11:23	Chouser	ion3.
11:23	hiredman	Chouser: have you seen slime.vim?
11:23	aravind	I see, but don't you like the convenience of having a few key strokes compile/eval what you are working on?
11:23	hiredman	http://technotales.wordpress.com/2007/10/03/like-slime-for-vim/
11:24	Chouser	vim with syntax coloring and indentation support. repl with rlwrap and vi-like bindings for tab completion and history.
11:24	hiredman	it lets you send code to a repl running in screen
11:24	Chouser	aravind: well, I have that. maybe more keystrokes than with slime, but not too bad.
11:25	Chouser	a couple keystrokes to select a portion of the code, an ion3 keystroke to focus on the repl, a keystroke to paste and execute.
11:25	ezyang	Gave up with vimclojure, am setting up emacs
11:25	aravind	Chouser: ion3 is supposed to be an awesome wm.. I used to use stumpwm for a while, but I finally gave up on tiling wms, switched to openbox (but was able to retain most of my keybindings).
11:25	Chouser	hiredman: I don't think I've tried that particular one. I did use whatever was before gorilla some, but it never really hooked me.
11:26	hiredman	Chouser: it is different from gorilla
11:26	Chouser	And I don't particularly like vim (vimscript in particular), but it's what I know, and the keybindings are undeniably powerful.
11:26	piyo	ezyang: what is your os
11:27	aravind	Chouser: how about auto navigating to your function definitions if you want to look some stuff up? You would have to hack it up with etags or something like that for equivalent functionality.
11:27	Chouser	I suppose I should try emacs, but the thought of having to learn elisp in order to customize it makes me gag a little.
11:27	hiredman	you start a repl inside a screen session and then you tell slime.vim the name of the screen session and the name of the window the repl is in, and it just sort of pastes the vode into the repl
11:27	hiredman	very loosely coupled
11:27	stuartsierra	Chouser: it's not that bad, 99% of the customization you'll ever want is in the customize GUI.
11:28	Chouser	hiredman: yeah, that sounds like pre-gorilla (sorry, can't remember the name). He had some vim/ruby code that sent forms to a screen session.
11:28	ezyang	piyo: Jaunty
11:28	Chouser	...and I really must have vim bindings. the last couple times I tried switching to emacs I tried to do things the Emacs Way. I'm done with that.
11:29	aravind	Chouser: well.. it takes time.
11:29	Chouser	I know Chousuke uses vi bindings in emacs, but my recent attempts at that were unsatisfactory.
11:29	aravind	but then, if you are productive with your env, thats all that really matters.
11:30	Chouser	aravind: oh, I know. My last attempt at emacs went far enough that I was pretty comfortable with emacs bindings for navigating a file. Took time, but was somewhat rewarding.
11:31	Chouser	...but then I needed features that were not built in, and spent some time trying to port a plugin from xemacs to emacs (or the other way around, I forget) ... largely failed, and then discovered the feature I needed was built in to vim.
11:31	piyo	ezyang: sudo aptitude install ant open-jdk-devel ... # etc...
11:31	piyo	ezyang: ?
11:31	aravind	I was a huge vim proponent, but its a nightmare trying to customize or hack the configs for anything other than the basic tabwidth, or syntax settings in it. So, I have been using emacs for some time now.
11:32	Chouser	now I'm just whining. I want emacs flexibility + vim keybindings + clojure core (for multithreading, customiaztion, etc.)
11:32	Chouser	when can I have that? :-)
11:33	ezyang	Oh, I already can run Clojure
11:33	ezyang	(re piyo)
11:33	ezyang	I was trying to "improve my productivity" with a non-crappy repl environment
11:33	aravind	Chouser: have you give emacs viper mode a chance, it may be just enough vi for you.
11:33	Chouser	I have. I should try again.
11:34	Chouser	I'm frequently startled by missing features, but I should try to get over it.
11:35	aravind	thats how I switched..
11:35	Chouser	you don't use it anymore
11:35	Chouser	?
11:36	aravind	vim, nope.. not unless I am in a remote system, when I need to use it for quick things. (I am a sysadmin).
11:36	Chouser	I mean, you don't use viper mode anymore?
11:37	aravind	oh viper mode.. nope, I used it to get started.. used it for a few months, then I tweaked the viper levels down to make it more and more emacsy, and finally turned it off for good.
11:37	Chouser	I just can't imagine living without command mode.
11:38	aravind	I did stick to pure viper (full vi) mode for a few months though.
11:39	aravind	command mode annoys me now, when I go to remote systems and start typing ALT-n and ALT-b in vim :)
11:39	Chouser	Holding down the ALT key seems like an inconvenient sort of command-mode.
11:39	Chouser	:-)
11:41	aravind	hehe, yeah.. like I said, it takes time :)
11:42	Chouser	see, and that would be fine if I were deeply convinced of the Rightness of emacs. But the language, the lack of concurrency, etc. weaken that conviction.
11:42	aravind	I still do like vi mode for other things though. my mutt is all vi mode and so is lynx (though I don't use that much these days).
11:43	aravind	Chouser: for me, it was more of a convenience thing and the fact that its immensely customizable should I need to.
11:43	Chousuke	I finally got visual block mode working properly with emacs/vimpulse.
11:44	Chousuke	turns out I had to disable CUA mode because it was screwing up the rendering for some reason
11:44	Chouser	Chousuke: really? works great here! in vim. :-) :-)
11:44	Chousuke	I still think emacs is fundamentally superior to vim
11:44	Chousuke	the interface is just not as good :)
11:44	Chouser	heh
11:45	Chousuke	elisp lacking concurrency support is a big wart though, but at least it's not vimscript :P
11:46	Chousuke	I wonder how they're going to go about adding threading to emacs.
11:46	aravind	although I will admit, gnus has defeated me, multiple times. I have tried and failed to adopt it as my mail client. Every time I give it a shot, I go running back to mutt :)
11:47	Chouser	I've never been a heavy email user, but I got gnus working nicely last time I tried.
11:47	piyo	ezyang: it's just that, when the installation asks you to "M-x clojure-install", it git-clones then does the ant build thing
11:48	ezyang	Oh yeah. No, the project I'm working on has its separate build environment, with hand-rolled jars and eveyrthing
11:48	aravind	Chouser: thats odd! you got gnus to play nice, but you have a hard time with emacs..
11:49	cemerick	does anyone have recommendations for swing app frameworks, aside from the NB RCP?
11:50	Chouser	aravind: I really tried hard last time, getting emacs going. I wasn't even a lisper then...
11:51	aravind	Chouser: it took me a few attempts.
11:53	aravind	Chouser: if you want to switch (I am not saying you should), I'd start small. Don't try to get your entire env converted and working the way you think it should.
11:53	aravind	Chouser: I'd start with full blown viper mode.. etc..
11:55	Chouser	:-)
11:55	Chousuke	viper doesn't have visual mode though.
11:56	aravind	I have used them both enough, that I don't really mind the taunting.
11:56	aravind	I take the zen approach and go "whatever works for you" :)
11:56	piyo	aravind: I like editting with root privs from emacs , /sudo::/etc/hosts , etc
11:56	Chousuke	I still use vim for some stuff
11:57	Chousuke	but for clojure editing I need emacs.
11:57	aravind	piyo: hehe
11:58	piyo	except emacs first needs to be installed into the os, while vi is sitting there
11:58	aravind	piyo: oh wait a minute.. you are serious?
11:59	piyo	aravind: M-x butterfly, baby
11:59	Chousuke	quite often emacs is too; but vi is pretty universal.
11:59	aravind	phew!
11:59	hiredman	piyo: well, the vi freebsd comes with is really vi, not vim
11:59	piyo	so I'm like sudo vi /etc/portage/package.mask # add cutting edge emacs
12:00	hiredman	which, uh, I'd rather not use for coding
12:00	piyo	aravind: you do use emacs TRAMP
12:00	piyo	aravind: ?
12:00	aravind	piyo: I do, if I have to do extended editing, and I can't replicate the env locally.
12:01	piyo	I was being serious with /sudo::/etc/hosts
12:01	aravind	no way!
12:01	aravind	you can't be!
12:01	piyo	I mean, it works
12:02	ezyang	Huh. Even with emacs+slime, it doesn't dynamically automatically update things. feh
12:02	piyo	I do set sudo so that I don't enter my password
12:02	aravind	piyo: sure does, but its like writing full blown swing application to cat/view a 10 line text file.
12:03	piyo	sometimes you want to M-x rectangle-yank inside a config file
12:03	piyo	:)
12:03	piyo	oh wait, you said 10 lines
12:04	piyo	I guess you could bang on "." for a while
12:04	aravind	piyo: vim + ex commands usually work fine for that kind of stuff for me.
12:04	piyo	aravind: as for me
12:05	piyo	hiredman: I only seem to use vi features, not vim
12:06	piyo	</offtopic> ?
12:06	aravind	I am out, have to get ready and head in to earn that paycheck.
12:15	piyo	let's talk about clojure
12:15	hiredman	~clojure
12:15	clojurebot	clojure is like life: you make trade-offs
12:16	hiredman	~clojure
12:16	clojurebot	clojure > scheme
12:16	gnuvince	,(compare "clojure" "scheme")
12:16	clojurebot	-16
12:17	gnuvince	;-)
12:17	Chouser	,(expression-info '(Integer. "5"))
12:17	clojurebot	{:class java.lang.Integer, :primitive? false}
12:17	Chouser	,(expression-info '(int (Integer. "5")))
12:17	clojurebot	{:class int, :primitive? true}
12:17	gnuvince	That's pretty neat
12:18	Chouser	I wish there were a way to use it on expression deep inside a nested context.
12:24	piyo	hey technomancy thanks for that emacs + clojure blog post, it was useful
12:24	technomancy	piyo: great, glad it was helpful
12:24	piyo	:)
12:42	ezyang	Hmm, I still can't get repl reloading to work
12:45	ezyang	What was the command to reload the namespace again?
12:45	ozzilee	(require 'my-ns :reload-all) ?
12:46	ezyang	Yeah, doesn't seem to do anything
12:47	ezyang	http://pastebin.com/mefa4d10
12:47	stuartsierra	It won't delete old definitions.
12:47	ezyang	Oh.
12:47	ezyang	Ok, how should I do that?
12:47	stuartsierra	Try (remove-ns 'my-ns) first.
12:48	ezyang	Now I get Var plyzrdata.parser/parse-hoststat-line is unbound.
12:50	ezyang	(an IllegalStateException)
12:50	stuartsierra	Maybe your definitions are out of order?
12:51	ezyang	What do you mean by that?
12:51	ozzilee	ezyang: You have to define functions before you use them, unfortunately
12:51	ezyang	Oh, I know why
12:52	ezyang	Removing the namespace doesn't remove the function
12:52	ezyang	ozzilee: It loads fine the first time
12:52	ozzilee	ezyang: Ah, ok.
12:52	ezyang	So how would I remove all of the functions from a namespace...
12:53	hiredman	ns-unmap
12:54	hiredman	,(ns-map ns)
12:54	clojurebot	{sorted-map #'clojure.core/sorted-map, read-line #'clojure.core/read-line, re-pattern #'clojure.core/re-pattern, pprint-map #'clojure.contrib.pprint/pprint-map, keyword? #'clojure.core/keyword?, val #'clojure.core/val, ProcessBuilder java.lang.ProcessBuilder, Enum java.lang.Enum, SuppressWarnings java.lang.SuppressWarnings, compile-path #'clojure.core/compile-path, max-key #'clojure.core/max-key, list* #'clojure.core/
12:55	ezyang	Hm, so I would need to map ns-unmap on map
12:56	ezyang	,(map (partial ns-unmap `plyzrdata.parser) (ns-map `plyzrdata.parser))
12:56	clojurebot	java.lang.Exception: No namespace: plyzrdata.parser found
12:56	ezyang	Erm, I get the error rclojure.lang.PersistentHashMap$LeafNode cannot be cast to clojure.lang.Symbol
12:56	replaca	hiredman: autodoc json now has :namespace element for each entry in :vars
12:56	replaca	hiredman: that's what you were after, right?
12:56	ezyang	Given how difficult this seems to be, I'm probably going about this the wrong way
12:59	hiredman	replaca: yesssir
12:59	ezyang	Can I make clojure start the repl in a specific namespace?
12:59	replaca	hiredman: cool
12:59	replaca	hiredman: did you modify clojurebot to ignore autodoc updates?
13:00	hiredman	replaca: yes
13:01	replaca	hiredman: good idea, but I was getting used to the echo :-)
13:02	hiredman	displeasure was expressed in my direction
13:02	replaca	hiredman: yeah, makes sense. no real information there.
13:03	hiredman	(doc xml1->)
13:03	clojurebot	"clojure.contrib.zip-filter.xml/xml1->;[[loc & preds]]; Returns the first item from loc based on the query predicates given. See xml->"
13:04	replaca	nice
13:05	hiredman	so couchdb has no security features built in?
13:07	mrsolo	ah missing :gen-class i am such a dimwit
13:17	technomancy	hiredman: since it's all run over HTTP it's pretty easy to secure at the proxy level
13:17	technomancy	no need to build it into the DB
13:53	mrsolo	are there some online resource that help you to learn about writing macros?
13:53	dnolen	check the Clojure wiki
13:53	dnolen	also Practical Common Lisp and On Lisp are good general resources about macro writing and they are available for free
13:53	Chouser_1	mrsolo: I learned by reading On Lisp, which is free online
13:54	mrsolo	ok
13:55	mrsolo	going through core.clj... ` seems to be in random places and i don't see the significants :-)
13:55	Chouser	On Lisp uses mostly Common Lisp and some Scheme, but the bulk of it is meaningful for Clojure, with a few syntactic adjustments
13:55	Chouser	heh, it's not random, I assure you. :-)
13:55	mrsolo	of course
14:00	ezyang	What are the performance properties of partial application in clojure?
14:01	ezyang	Does Clojure magically evaluate things it can evaluate when I do a partial application?
14:01	hiredman	partial just returns a new function
14:01	hiredman	uh
14:01	hiredman	it is function application, not magic
14:01	hiredman	~def partial
14:02	ezyang	Ok :-(
14:02	hiredman	no magic whatsoever, not even a macro
14:02	hiredman	why the :-( ?
14:02	ezyang	(unrelated) I am currently editing files in Vim, popping over to emacs and using that to run them
14:02	ezyang	It's great. :-P
14:03	dnolen	ezyang: the cost is an additional function call, but those are cheap.
14:03	dnolen	er
14:03	dnolen	no
14:03	dnolen	rather the speed of apply
14:07	ezyang	So, the question here is there's a pre-computation to one of the parameters that should be done, and I was wondering if I could do it inside the function
14:07	ezyang	but that's not hte case
14:08	hiredman	...
14:08	Chousuke	mrsolo: if the appearance of ` seems random to you, remember that it's just one way to write a list data structure that won't get evaluated.
14:08	ezyang	Btw, (load-file) is the magic I was looking for earlier on the channel
14:08	gnuvince	I got a general CS question for you guys: considering that getting the length and splitting a linked list are O(n) operations, is mergesort really a good candidate for sorting them?
14:09	Chousuke	mrsolo: macros must return clojure code, and clojure code is predominantly made of lists. thus, ` is very useful when making macros.
14:09	mrsolo	ah
14:09	Chousuke	mrsolo: you could write every macro without it too, though.
14:09	Chousuke	but that's a lot more complicated.
14:11	Chousuke	actually ` is not limited to quoting lists either, but that's where you see it most often.
14:11	Chousuke	,(let [a 1] `[1 2 a ~a])
14:11	clojurebot	[1 2 sandbox/a 1]
14:11	mrsolo	chousuke: i got this to work and i want to know why ..it tooks lot of trials and errors http://paste.lisp.org/display/81422 :-)
14:12	mrsolo	so ya reading some information on why and how of macros will be very helpful
14:12	Chousuke	mrsolo: did you try calling (macroexpand '(rp (+ 1 2))
14:13	Chousuke	actually, that macro is a bit weird.
14:13	mrsolo	hmm i didn't.. but that gave (rp (+ 1 2)) back
14:13	Chouser	mrsolo: that macro is not what you want.
14:14	Chousuke	right
14:14	Chousuke	it doesn't return clojure code.
14:14	Chouser	the use of 'eval' is your first hint that something's wrong.
14:14	mrsolo	ok
14:14	Chouser	mrsolo: if you want less than a whole book, we can give you a few tips.
14:15	mrsolo	yet it works somehow
14:15	Chousuke	mrsolo: your macro runs the println and time at compile time
14:15	Chousuke	mrsolo: it doesn't actually expand to any code :)
14:15	Chousuke	unless (eval a) expands to code
14:15	mrsolo	(rp (map list-single-files '("/tmp", "/tmp")))
14:15	mrsolo	gives back desired result.. though
14:15	Chouser	for example, first write out an example of calling your macro. Then write out the code you'd like your macro to produce for that example.
14:15	Chouser	Chousuke: yikes. good point.
14:15	Chousuke	mrsolo: but it doesn't happen at runtime
14:16	Chousuke	mrsolo: it happens at compile time.
14:16	mrsolo	ok
14:16	Chouser	so you've got an example of calling your macro there. that's a great start.
14:16	Chousuke	mrsolo: ask yourself: if rp were a function, what does it return?
14:16	Chouser	now, what code would you like your macro to produce in that case?
14:16	mrsolo	ok
14:17	Chouser	Maybe: (time (println "(map list-...)" (map list-...))) right?
14:18	mrsolo	right
14:18	Chouser	so, your macro should be a function that accepts the list '(map list-...) and returns the list '(time (println ...))
14:19	Chouser	you can write regular code without ` or ~ do to that.
14:19	Chouser	if you want
14:19	Chousuke	actually.
14:19	mrsolo	well it was a function origional.. but i was tire dof quoting
14:19	mrsolo	all it does it print the sexp and time to run it
14:20	Chousuke	it might be good practice to actually write a function that does that.
14:20	mrsolo	oh?
14:20	Chouser	it would look something like (defmacro rp [a] (list `time (list `println (str a) a)))
14:20	mrsolo	(rp '(+ 2 3)) gets kinda tedous.. i though macro will let me do (rp (+ 2 3)) instead
14:20	Chouser	do you see why?
14:21	mrsolo	i see
14:21	ezyang	Hey all; what data-structure should I use if I will have a mapping like 0 => :tag1, 1 => :tag2, 2 => :tag3, etc
14:21	ezyang	There will a dozen-ish elements
14:21	ozzilee	ezyang: Hashmap?
14:21	ezyang	That seems like overkill...
14:21	ozzilee	Er. array I suppose.
14:21	ezyang	Is the array functional?
14:21	hiredman	ozzilee: vector
14:21	ozzilee	[:tag1 :tag2 :tag3 :tag4]
14:22	mrsolo	chouser: thanks!
14:22	ozzilee	Yeah, vector, sorry :-)
14:22	hiredman	ozzilee: that is a vector
14:22	stuhood	if the indexes will always be incrementing integers, then yea... a vector
14:22	ezyang	Does the vector give me O(1) access?
14:22	dnolen	yup
14:22	ezyang	Yup, always will be incrementing integers
14:22	ezyang	Awesome
14:22	hiredman	,(keys [:a :b :c])
14:22	clojurebot	clojure.lang.Keyword cannot be cast to java.util.Map$Entry
14:22	hiredman	:(
14:23	stuhood	aw... that should work
14:23	hiredman	,(keys (map vector [:a :b :c] (range 20)))
14:23	clojurebot	clojure.lang.LazilyPersistentVector cannot be cast to java.util.Map$Entry
14:23	hiredman	Grrr
14:23	hiredman	,(map (comp second vector) [:a :b :c] (range 20))
14:23	clojurebot	(0 1 2)
14:24	ezyang	Hm. How do I convert a list to a vector...
14:24	hiredman	,(vec '(1 2 3 4))
14:24	clojurebot	[1 2 3 4]
14:24	ezyang	Sweet
14:24	hiredman	ezyang: clojure.org/api
14:25	ezyang	Yeah, sorry about that; should have looked that up first
14:25	Chousuke	(let [myfn (fn [lst] (concat lst '(2)))] (myfn '(+ 1))); mrsolo
14:25	Chousuke	,(let [myfn (fn [lst] (concat lst '(2)))] (myfn '(+ 1))); damn
14:25	clojurebot	(+ 1 2)
14:25	ezyang	Here's anot so easy to lookup question: when does clojure approve of (comp)?
14:25	Chousuke	mrsolo: see how that function returns clojure code?
14:25	hiredman	ezyang: "approve" ?
14:26	hiredman	~def comp
14:26	Chousuke	mrsolo: now, if you wanted to use myfn to write a macro that appends a 2 at the end of a clojure list form, you'd just do: (defmacro foo [form] (myfn form))
14:26	ezyang	For example, I could do something like (comp vec map) but that seems a little poor...
14:26	hiredman	"poor"?
14:27	Chousuke	mrsolo: notice, no quotes; myfn already returns clojure code :)
14:27	ezyang	as in, poor form
14:27	hiredman	why would you say that?
14:27	Chousuke	mrsolo: if you can understand why this works, then you already are well on your way to understanding macros.
14:28	ezyang	hiredman: Sort of gut feeling. No good reason
14:28	hiredman	my feeling is partial and comp don't get used often enough
14:28	ezyang	New question: I'm looking at some code that is building maps using a reduce()
14:28	ezyang	I feel like there is a... better way of doing this
14:28	hiredman	people just use function literals everywhere
14:29	ezyang	maybe involving zipmap
14:29	hiredman	ezyang: better way of composing functions?
14:29	ezyang	Oh, sorry, I'm on another topic now :-P
14:30	mrsolo	chousuke: nice big difference between reading and writing though.. still lot a long way to go
14:30	Chouser	ezyang: did you look at 'into'?
14:30	stuhood	ezyang: reduce is a relatively good way, 'into' would be another
14:30	hiredman	~def vec
14:30	Chousuke	mrsolo: yeah, but it's not that difficult once you really understand what macros do
14:30	hiredman	I imagine vec is faster then into
14:30	hiredman	than
14:31	digash	Does anybody know Scala here? I need to do a presentation on Clojure to Scala NY group. I've done Clojure to Java programmers before, but what Scala guys would want to here?
14:32	ezyang	stuhood: Why wouldn't zipmap work?
14:32	Chouser	digash: they want to talk about contravarient type signatures
14:32	ezyang	Say I have a vector [:a, :b, :c] and a list (1, 2, 3) and I want {:a 1, :b 2, :c 3}
14:32	hiredman	digash: my guess is smooth interop with java Collections
14:32	stuhood	ezyang: in that case, zipmap is the perfect fit
14:32	ezyang	,(zipmap '[a b c] '(1 2 3))
14:32	clojurebot	{c 3, b 2, a 1}
14:32	mattrepl	digash: macros over automated closures for designing DSLs
14:32	hiredman	scala is having a huge shakeup over their collections stuff right now
14:32	ezyang	Ok.
14:33	hiredman	~scala
14:33	clojurebot	"you can usually accomplish a lot by laboriously enumerating type arguments everywhere." -- seen in #scala
14:33	Chousuke	mrsolo: they take clojure code as parameters: if you have a (foo [a]) macro and call it as (foo (+ 1 3)) then (= a '(+ 1 3)) is true. Then you operate on the parameters like any other function, and return new code (my earlier example would concat '(+ 1 3) and '(2), returning '(+ 1 3 2))
14:33	Chousuke	mrsolo: this function is then run at compile time, and the macro invocation is replaced with its return value.
14:34	Chouser	digash: though I was never a committed Scalar, what brought me to Clojure was how much you could get done without ever declaring a type, and how easily a DSL can be made without needing scala's too-clever auto-casting (or whatever it's called that I've now forgotten)
14:34	Chousuke	Scalar :P
14:34	Chouser	:-)
14:35	hiredman	yeah, I think clojure's java interop is (surprisingly?) better then scalas except possibly for Annotations stuff
14:35	Chousuke	mrsolo: you can have side-effects like println in macros, but usually it's not what you want, since it's run at compile time.
14:35	digash	Chouser: thanks, I try DSL. Then the next questions what are the best DSL examples in Clojure?
14:36	Chousuke	mrsolo: however, what you DO often want is return code from a macro that has side-effects
14:36	hiredman	digash: you could ask in #scala to see what they want to hear about
14:36	Chouser	digash: enlive
14:36	digash	hiredman: thanks, i would go there but first wanted to swim in the friendlier waters.
14:36	hiredman	heh
14:37	hiredman	those darn scalars!
14:37	Chousuke	mrsolo: if returning code from a function makes sense to you, then you understand what "code as data" really means.
14:37	mrsolo	ya
14:37	mrsolo	i see why not
14:37	mrsolo	so
14:38	mrsolo	defmaco can be used to intentionally run some code during compile time?
14:38	mrsolo	for whatever the reason
14:38	Chouser	digash: http://github.com/Lau-of-DK/clojureql/tree/master
14:38	mattrepl	digash: someone in the crowd will probably ask about performance, so having some information on type annotations and unchecked arithmetic would be prudent
14:38	stuhood	digash: incanter seems pretty cool too http://github.com/liebke/incanter/tree/master
14:39	Chousuke	mrsolo: there are rules.
14:39	digash	mattrepl: is Scala performance on the par with Java native types?
14:39	Chousuke	mrsolo: it's not really compile time I guess, but "macro expansion time". usually macros are expanded first, and THEN stuff gets compiled.
14:40	mrsolo	what are the rules?
14:40	mattrepl	digash: I believe idiomatic Scala is more on par with Java than idiomatic Clojure
14:40	Chouser	mrsolo: sure, On Lisp shows some interesting performace tweaks by computing stuff at macro-expand time.
14:40	mrsolo	one can implement something similar to perl BEGIN i guess
14:41	Chousuke	mrsolo: a macro can't depend on runtime data, obviously :)
14:42	hiredman	mattrepl: scala still does a lot of intermediate object allocation
14:42	Chousuke	mrsolo: you can use whatever is available at macro expansion time, though. global vars etc.
14:42	hiredman	they also do what they call "de-scalafying" to get closer to java performance
14:43	Chousuke	scaling down? :)
14:43	Chousuke	(the mountain)
14:44	Chouser	toward the Java lowlands?
14:44	hiredman	yeah
14:44	Chousuke	clojure people can just take a paren and use it as a sled.
14:45	mattrepl	digash: destructing bind and keyword and rest params might be good material too
14:45	Chousuke	though the ride down might be fun but hitting the ground probably isn't.
14:45	Chousuke	hmm
14:46	hiredman	http://www.codecommit.com/blog/scala/scala-collections-for-the-easily-bored-part-1
14:46	Chousuke	about destructuring bind, I was wondering if it is possible to improve the destructuring that it's always equivalent to a sequential let when the source form is known at macro expansion time to match the target. :/
14:47	ezyang	Is there a list of clojure's string -> FOO conversion functions?
14:47	Chouser	ezyang: clojure doesn't have many of those. Mostly you use Java methods.
14:47	ezyang	ick
14:48	Chouser	ezyang: 'keyword' and 'symbol' take strings...
14:48	Chouser	ezyang: ick?
14:48	Chousuke	eg. expanding (let [[a b c] [1 2 3]]) to (let [a 1 b 2 c 3]) instead of the weird (let [a (get somegensym 0 nil) ...])
14:48	Chouser	,(Integer/parseInt "F00" 16)
14:48	clojurebot	3840
14:48	hiredman	,(.toUpperCase "foo")
14:48	clojurebot	"FOO"
14:49	Chousuke	I have seen complaints about destructuring let being inexplainably slower than non-destructuring let, and I think it could be fixed :/
14:49	hiredman	,(-> "foo" .toUpperCase .toLowerCase ((partial map int)) ((parital reduce *)))
14:49	clojurebot	java.lang.Exception: Unable to resolve symbol: parital in this context
14:50	hiredman	,(-> "foo" .toUpperCase .toLowerCase ((partial map int)) ((partial reduce *)))
14:50	clojurebot	1256742
14:50	ezyang	Why did... Integer/parseInt take two parameters?
14:50	clojurebot	why not?
14:50	Chousuke	ezyang: it's overloaded.
14:50	hiredman	ezyang: because you have to give it a base
14:50	ezyang	Ok... I need to curry the second parameter
14:50	hiredman	,(Interger/parseInt "10" 2)
14:50	clojurebot	java.lang.Exception: No such namespace: Interger
14:50	ezyang	This is going to be complicated
14:50	hiredman	,(Integer/parseInt "10" 2)
14:50	clojurebot	2
14:51	hiredman	,(Integer/parseInt "10" 8)
14:51	clojurebot	8
14:51	Chousuke	,(Integer/parseInt "10"); works too I think
14:51	clojurebot	10
14:51	ezyang	Oh, ok
14:51	cemerick	Chousuke: I can vouch for that. Got a 10% speedup on a key inner loop by eliminating [[v0 v1]] and using [v] with (v 0) and (v 1)
14:51	ezyang	,Integer/parseInt
14:51	clojurebot	java.lang.Exception: Unable to find static field: parseInt in class java.lang.Integer
14:52	ezyang	Hmm... is it a first class function?
14:52	mrsolo	cemerick: ack!
14:52	Chouser	,(let [from-hex #(Integer/parseInt % 16)] (from-hex "fa7"))
14:52	clojurebot	4007
14:52	ezyang	But you anonymized it...
14:52	cemerick	mrsolo: ack?
14:52	ezyang	I guess that works
14:53	mrsolo	cemerick: huge performance penality for such an innocent construct
14:53	Chouser	ezyang: no, it's a static method, not a Clojure function.
14:53	Chousuke	cemerick: the problem is that I don't think it's possible to help in the case where you do destructuring like [[v0 v1] v]
14:53	ezyang	:-* Well, I guess that's the price you pay for getting Java
14:53	Chousuke	cemerick: since the form of the source is not known
14:53	cemerick	mrsolo: yeah...well, it was a very hot spot, FWIW
14:53	Chouser	Chousuke: [v0 (v 0) v1 (v 1)] ?
14:53	Chouser	oh, if you want to allow for lists
14:54	cemerick	yeah, I don't think it's such a big deal.
14:54	cemerick	I got that particular hint from a post that gnuvince made recently, and I remember some commenters trashing on clojure due to the current state of affairs, so maybe CL doesn't have that issue. shrug
14:55	Chousuke	so why would (nth v 1) be slower than (v 1)? :/
14:55	cemerick	one fewer method call?
14:57	Chousuke	~source nth)
14:57	clojurebot	No entiendo
14:57	Chousuke	gah
14:57	Chousuke	~source nth
14:57	ezyang	Does clojure have a built-in no-op?
14:57	Chouser	,(do)
14:57	clojurebot	nil
14:57	Chousuke	identity?
14:58	cemerick	ezyang: identity
14:58	Chouser	nil
14:58	ezyang	Ok.
14:58	Chousuke	depends on the context I guess.
14:58	dnolen	,(do nil (+ 4 5))
14:58	clojurebot	9
14:58	cemerick	Chousuke: See, there's actually a number of levels indirection with nth
14:58	ezyang	,(nil 1)
14:58	clojurebot	java.lang.IllegalArgumentException: Can't call nil
14:58	ezyang	,(identity 1)
14:58	clojurebot	1
14:58	gnuvince	The doc says that nth is O(n) for sequences while Vectors can index in O(log_32 n)
14:59	Chousuke	cemerick: I think it should inline the not-found case too :/
14:59	Chousuke	gnuvince: (v 1) is O(log_32 n) too, that's no different :)
15:00	cemerick	Chousuke: the function-call overhead could have been the difference in my case.
15:00	Chousuke	I think it's just that in destructuring, nth is used with the default value and it's not inlined.
15:01	Chouser	(v 1) compiles to (.invoke v 1), which calls v.nth((1).intValue())
15:01	Chousuke	okay, so it's basically equivalent.
15:02	Chousuke	I wonder if the slowdown goes away if the 3-parameter case is added to inline arities as well
15:02	Chouser	I wonder if the Var lookup for 'nth' itself hurts much.
15:04	Chousuke	or perhaps c.lang.RT/nth does instanceof lookups that slow it down :/
15:07	Chousuke	there's an enormous difference between doing (nth v 3) and (nth v 3 1) 10 million times.
15:08	Chouser	wild
15:11	Chouser	,(let [v [1 2 3]] (time (dotimes [_ 10000] (v 1))))
15:11	clojurebot	"Elapsed time: 6.454 msecs"
15:11	Chouser	what am I doing wrong here?
15:11	Chouser	,(let [v [1 2 3]] (time (dotimes [_ 1000000] (v 1))))
15:11	clojurebot	"Elapsed time: 101.76 msecs"
15:12	Chouser	hm, that looks vaguely sane. On my machine doing the lookup *100 more times only costs 0.5 more msecs.
15:12	Chouser	,(let [v [1 2 3]] (time (dotimes [_ 10000000] (v 1))))
15:12	clojurebot	"Elapsed time: 85.344 msecs"
15:12	hiredman	"Elapsed time: 390.49132 msecs"
15:12	hiredman	:(
15:13	Chouser	Chousuke: oh!
15:13	Chouser	destructuring uses (nth v x nil)!
15:14	Chouser	Chousuke: the notFound slowdown you spotted may be the main culprit for destructuring
15:14	Chousuke	inlining the 3-parameter case is still slower, but saves 200ms for 10 million lookups compared to not inlining
15:15	Chouser	what do you mean by inlining there?
15:15	Chousuke	nth has {:inline (fn [c i] `(. clojure.lang.RT (nth ~c ~i))) :inline-arities #{2}}
15:15	Chousuke	just adding the 3-parameter version there
15:16	Chouser	ah!
15:17	ezyang	Let's say I have a map of values and a map of functions and I'd like a map of (function value). What do I do?
15:18	ezyang	(the maps keys perfectly align)
15:19	Chousuke	hm
15:19	hiredman	(map #(%1 %2) (vals functions) (vals values)) would return a seq of (function value)
15:19	Chousuke	right... (map apply (vals fmap) (vals values))
15:19	hiredman	or that
15:20	Chousuke	hmm
15:20	mrsolo	clojurebot runs on fast machine!
15:20	hiredman	uh
15:21	hiredman	Not Really
15:21	Chouser	I'd be nervous about using val seqs from two different maps
15:21	mrsolo	"Elapsed time: 222.746 msecs"
15:21	mrsolo	or mine is a very slow one
15:23	hiredman	(let [fmap {:a idenity :b identity} vmap {:a 1 :b 1}] (reduce #(assoc %1 %2 ((fmap %2) (vmap %2))) {} (vals fmap))
15:23	hiredman	,(let [fmap {:a idenity :b identity} vmap {:a 1 :b 1}] (reduce #(assoc %1 %2 ((fmap %2) (vmap %2))) {} (vals fmap))
15:23	clojurebot	EOF while reading
15:23	hiredman	bah!
15:24	Chousuke	hmm
15:24	Chouser	,(let [funcs {:a inc :b dec} values {:b 5 :a 10}] (into {} (for [[k f] funcs] [k (f (values k))])))
15:24	clojurebot	{:b 4, :a 11}
15:25	tashafa	qq
15:25	Chousuke	,(map (comp apply apply) (vals (merge-with vector {:foo + :bar -} {:foo 5 :bar 1})))
15:25	clojurebot	java.lang.IllegalArgumentException: Wrong number of args passed to: LazilyPersistentVector
15:25	tashafa	how do you install clojure-mode.el thru ELPA?
15:26	Chousuke	(vals (merge-with vector {:foo + :bar -} {:foo 5 :bar 1})))
15:26	Chousuke	gah
15:26	Chousuke	,(vals (merge-with vector {:foo + :bar -} {:foo 5 :bar 1})))
15:26	clojurebot	([#<core$_PLUS___3949 clojure.core$_PLUS___3949@482bad> 5] [#<core$___3975 clojure.core$___3975@46a55e> 1])
15:26	mrsolo	M-x package-install clojure-mode
15:26	tashafa	mrsolo thanks!
15:27	Chouser	Chousuke: ooh, I like where you're going.
15:27	Chousuke	safer than relying on the order anyway
15:27	tashafa	mrsolo: hmm, no match
15:27	Chousuke	(apply hash-map (merge-with vector {:foo '+ :bar '-} {:foo 5 :bar 1}))))
15:27	Chousuke	,(apply hash-map (merge-with vector {:foo '+ :bar '-} {:foo 5 :bar 1})))) ;a hsfjslkfjg
15:27	clojurebot	{[:foo [+ 5]] [:bar [- 1]]}
15:28	Chouser	, (let [funcs {:a inc :b dec} values {:b 5 :a 10}] (merge-with #(%1 %2) funcs values))
15:28	clojurebot	{:a 11, :b 4}
15:28	Chousuke	aha, even better.
15:28	mrsolo	tashafa: package-list-packages will list available packages
15:28	mrsolo	tash: it should be in there
15:29	mrsolo	tash: you can navirage then do package-menu-execute afterward 'I' to mark for install
15:31	tashafa	go it
15:31	tashafa	thanks man
15:31	tashafa	got it*
15:31	mrsolo	np
15:32	Chousuke	(let [fs {:foo + :bar - :zonk reduce} params {:foo [1 2] :bar [10 5] :zonk [conj #{} [1 2 3]]}] (merge-with apply fs params)); fun
15:32	Chousuke	,(let [fs {:foo + :bar - :zonk reduce} params {:foo [1 2] :bar [10 5] :zonk [conj #{} [1 2 3]]}] (merge-with apply fs params)); ASDFSDJFK
15:32	clojurebot	{:foo 3, :bar 5, :zonk #{1 2 3}}
15:33	Chousuke	how is it that I ALWAYS forget the comma
15:33	ezyang	So, merge-with is the magic?
15:33	Chousuke	yeah
15:34	ezyang	I wonder if it'll 'splode if the keys don't match up
15:34	Chousuke	it probably will
15:35	Chousuke	or rather, this happens:
15:35	Chousuke	,(let [fs {:foo + :bar - :zonk reduce} params {:foo [1 2] :bar [10 5] :zonk [conj #{} [1 2 3]] :nonexistent 5}] (merge-with apply fs params));
15:35	clojurebot	{:nonexistent 5, :foo 3, :bar 5, :zonk #{1 2 3}}
15:36	ezyang	,(merge-with apply {:foo +} {})
15:36	clojurebot	{:foo #<core$_PLUS___3949 clojure.core$_PLUS___3949@482bad>}
15:37	ezyang	Ew
15:37	Chousuke	yeah, the function printing thing is ugly ;(
15:37	Chousuke	need metadata for functions so it can be made prettier!
15:38	Chousuke	should say something like #<Fn clojure.core/+>
15:41	hiredman	clojure.core/+ is a symbol
15:42	Chousuke	that's why it says Fn in there
15:42	hiredman	why would the function care about a symbol it might be bound to?
15:42	Chousuke	okay, well, it could be just #<Fn +>
15:42	hiredman	+ is also a symbol
15:42	Chousuke	yes, but it's the function's name.
15:42	Chousuke	and if it has no name #<lambda 2398449> or something
15:43	Chousuke	point being, something that easily identifies the function's name and possibly origin
15:44	hiredman	the only thing a function really maps to is a java class, which is what the current .toString is
15:44	hiredman	,(.toString (fn []))
15:44	clojurebot	"sandbox$eval__1992$fn__1994@1be0369"
15:44	Chousuke	hiredman: that's why functions need metadata.
15:46	Chousuke	the .toString is useless and icky anyway so if there were metadata it could be used
15:49	Chousuke	I wonder if there's something that prevent IFn or AFn or something from just extending IMeta :/
15:52	ezyang	Question: I want to dynamically define a function, like (def func (func-gen 0))
15:52	ezyang	But it would be a defmethod
15:52	ezyang	So I'm a little confused how to do it (defmethod being a macro and such)
15:53	ezyang	Can I put the defmethod inside of another function?
15:54	Chouser	ezyang: usually best in these cases to do what the macro does, rather than try to call it.
15:54	Chouser	(.addMethod multifn :value (fn ...))
15:55	stuartsierra	Chouser: where are the dispatch arguments?
15:55	stuartsierra	Oh, :value, I get it.
15:56	stuartsierra	Speaking of multimethods, did anyone ever figure out multiple-arg dispatch with inheritance?
15:56	stuartsierra	That is, (defmulti m (fn [x y] [(class x) (class y)]))
15:59	stuartsierra	Oh, never mind, isa? works on vectors of derived types.
16:05	ezyang	repl is giving me an exception, but not telling me where it came from...
16:05	Chouser	(.printStackTrace *e)
16:06	ezyang	Thanks!
16:12	ezyang	Hmm... apparently, #(%1 %2) is not equivalent to apply
16:12	Chouser	indeed not
16:12	Chouser	apply wants its final arg to be a collection, which it "unrolls" into the final args of the call.
16:13	Chouser	,(apply + 1 2 [3 4 5])
16:13	clojurebot	15
16:13	ezyang	savvy
16:26	ezyang	How do I introspect the contents of a multimethod?
16:26	Chouser	"contents"?
16:29	Chouser	,(doc methods) ; perhaps
16:29	clojurebot	"([multifn]); Given a multimethod, returns a map of dispatch values -> dispatch fns"
16:31	cemerick	it's unfortunate that the names of the fns installed as multimethods don't consist of, say, a concatenation of the method name and the dispatch value. That'd be handy, though probably dicey to implement safely.
16:33	stuartsierra	especially since the dispatch value could be absolutely anything
16:36	ezyang	Hey, does (load) do any dicey caching based on filemtimes?
16:38	Chouser	it checks file mtimes to determine if it should load .class or .clj
16:38	ezyang	Ouch
16:39	mrsolo	what if it is in resource file?
16:39	ezyang	A behavior of this is that multimethods don't get reinitialized properly
16:40	mrsolo	i mean if a resource file has both .class or .clj, what gets loaded?
16:40	hiredman	mrsolo: if the clj is newer, it gets loaded
16:42	Chouser	http://code.google.com/p/clojure/source/browse/trunk/src/jvm/clojure/lang/RT.java#373
16:43	ezyang	This is a likely bug, then
16:48	jkantz	in a single namespace make file_a, add a multimethod definition and (load "file_b")
16:48	jkantz	add a defmethod to file_b
16:48	jkantz	add another to file_c
16:49	jkantz	compile the namespace
16:49	jkantz	now change the file_b multi method
16:49	jkantz	and load-file on file_a
16:49	jkantz	the method in file_c will be gone
16:50	hiredman	a) you must be missing steps
16:50	hiredman	b) if by compile you mean AOT compile, you should not compile single segment namespaces
16:51	jkantz	"single segment namespaces"?
16:51	hiredman	~namespaces
16:51	clojurebot	namespaces are (more or less, Chouser) java packages. they look like foo.bar; and corresponde to a directory foo/ containg a file bar.clj in your classpath. the namespace declaration in bar.clj would like like (ns foo.bar). Do not try to use single segment namespaces. a single segment namespace is a namespace without a period in it
16:52	hiredman	~compile
16:52	clojurebot	the unit of compilation in clojure is the namespace. namespaces are compiled (not files). to compile a namspace the namespace needs to be on the classpath and so does ./classes/ (and the directory needs to exist) because clojure writes the class files to that directory. http://clojure.org/compilation
16:53	ezyang	The real code isn't single segment
16:54	jkantz	hiredman by b) do you rather mean you should not compile namespaces that have calls to load?
16:55	hiredman	no
16:55	hiredman	compiling namespaces that call load is fine
16:56	hiredman	it will cause the loaded code to be compiled
16:56	replaca	stuartsierra: it looks like the autodoc is right now. Can you confirm? http://code.google.com/p/clojure-contrib/wiki/StrUtils2ApiDoc
16:56	hiredman	jkantz: pastebin your test case
16:56	jkantz	right and then run into issues with defmulti and and defmethods in the loaded files when you try to reload the main file.
16:57	stuartsierra	replaca: closer, but not complete
16:57	replaca	what's missing?
16:57	jkantz	k, just a sec
16:57	hiredman	jkantz: I imagine you are running (defmulti ...) again which creates a new multimethod
16:57	stuartsierra	upper-case, lower-case, split, trim, contains?, get, split-lines, ltrim, rtrim...
16:58	hiredman	the new multimethod will not have any methods attached
16:58	replaca	k, I'll take a look
16:58	replaca	thanks
16:58	stuartsierra	sure, thanks for working on autodoc
16:58	ezyang	Right, but then when we (load) the sub files, the multimethod should then get repopulated
16:58	ezyang	What's happening is that (load) is not loading the subfiles
16:58	jkantz	hiredman, right, and due to the other files not being modified they aren't reloaded to re-add themethods
16:59	hiredman	so how is that a bug?
16:59	jkantz	not so much as a bug as a gotcha
16:59	ezyang	I would argue it's a bug
17:00	ezyang	There should be no functional difference between loading the clj and loading the class
17:00	hiredman	well, java cannot reload classes (unless you monkey with the classloader, I believe)
17:00	hiredman	so there must be
17:01	stuartsierra	Clojure monkeys with the classloader
17:01	jkantz	you'd have to pass on the dependency information to subsequent loads
17:01	replaca	stuartsierra: functions with no doc strings don't get put in the autodoc. Put an empty doc string if you believe they're that obvious
17:02	jkantz	~load
17:02	clojurebot	download is http://code.google.com/p/clojure/downloads/list
17:02	stuartsierra	Ah, ok
17:02	jkantz	,(doc load)
17:02	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."
17:02	replaca	stuartsierra: I think that explains all the funcs that were missed
17:04	hiredman	jkantz: is there a reason you are using load instead of require, use, etc
17:05	technomancy	I've played with defining methods in a different file from the defmulti. It's not a lot of fun when dealing w/ reloads.
17:06	hiredman	never had an issue with it with clojurebot
17:06	jkantz	hiredman, many individual methods organized each into their own file, don't want the extra namespaces
17:07	hiredman	ugh
17:07	technomancy	I think there's a way to force files to load even if they haven't changed.
17:08	technomancy	but yeah, if you step outside the one-file-per-namespace path, you're going to hit trouble
17:08	technomancy	no way around that
17:08	hiredman	is this a chrome thing? or is github's source code numbering brolen
17:08	hiredman	broken
17:08	jkantz	anyway touch * is the work around of the day
17:08	jkantz	hiredman why ugh? you find it gauche
17:08	clojurebot	why not?
17:09	hiredman	jkantz: sorry I was refering to loading up github and noticing the line numbers are off
17:10	jkantz	ah ok, I'm out of here, have a good weekend
17:16	replaca	stuartsierra: ok, I think the autodoc is right now
17:19	stuartsierra	replaca: yes, looks good. Thanks!
17:19	replaca	stuartsierra: thank you!
17:25	replaca	btw, for anyone who was here on Wednesday - turns out we broke the cable to the projector and that's why everything turned pink. A new cable fixed everything.
17:28	stuartsierra	Now you can copy files and streams in pure Clojure!
17:28	technomancy	oh, I was going to write that.
17:28	technomancy	nice. =)
17:28	technomancy	how about recursive copy now? =)
17:29	stuartsierra	You mean recursive copy of directories?
17:29	technomancy	yeah, so I don't have to shell out to "cp -r"
17:30	stuartsierra	Hmm. Worth having, although I was aiming to handle streams.
17:30	technomancy	stuartsierra: would you take that as a patch?
17:30	technomancy	yeah, it doesn't seem to belong in duck-streams
17:30	technomancy	there's probably enough stuff that could go into a file-utils namespace to justify its creation
17:31	stuartsierra	surely
17:32	technomancy	I've also got an extract-jar function that I thought should go in jar.clj
17:33	technomancy	but jar.clj could be subsumed into file-utils too
17:33	stuartsierra	Go for it.
17:33	technomancy	since there's only two functions in it
17:33	technomancy	stuartsierra: want me to make an issue+patch?
17:34	stuartsierra	Do you have a CA? Or commit access on contrib?
17:35	technomancy	just a CA
17:36	stuartsierra	Ok, you can make a patch or just email me the code.
17:37	technomancy	all righty
17:37	technomancy	just for extract-jar right?
17:37	technomancy	I haven't written recursive copy yet
17:37	stuartsierra	yeah, sure
17:37	stuartsierra	Well hop to it, then! :)
17:38	technomancy	hehe
17:48	replaca	stuartsierra: you're going crazy today!
17:49	stuartsierra	I'm shirking real work. :)
17:50	replaca	you and me both, man
18:00	replaca	stuartsierra: can I add fnmap.PersistentFnMap to compiled_classes in build.xml (that's where I'm putting anything that needs to be gen-classed to help support the autodoc)
18:00	replaca	I think that's fix the fnmap autodoc
18:01	stuartsierra	sure
18:01	replaca	k, thanks
18:04	stuhood	i have 1 hour and 30 minutes to write a mapreduce job in clojure for the first time
18:04	stuhood	let's see how this goes.
18:05	technomancy	stuhood: a hadoop mapreduce or just a pure-clojure one?
18:05	stuartsierra	stuhood: you've seen mine?
18:05	stuhood	technomancy: using the hadoop api from clojure... we already have some base classes in java
18:05	stuhood	stuartsierra: not yet... is it painful?
18:06	stuartsierra	The Clojure part is easy. The Hadoop API is... dense.
18:06	technomancy	stuartsierra: I read through yours. I think it would be super-helpful if you could make a blog post or something about how that works.
18:06	stuartsierra	I spent about a month learning Hadoop before I made serious use of it.
18:07	technomancy	reading the altlaw code was helpful, but trying to figure out which parts were specific to the task at hand vs which parts you need to copy was tricky.
18:07	stuartsierra	technomancy: yeah, it's on my agenda for... July?
18:07	technomancy	heh; ok cool.
18:08	technomancy	the job input and output formats are a lot to wrap your head around too
18:08	technomancy	I just got my example to the point where it would run; didn't actually get it to produce meaningful output. =)
18:22	stuartsierra	Good luck. I'm off.
18:22	triddell	technomancy: just created a blog and updated my tutorial: http://riddell.us/blog/2009/06/05/tutorials-available.html
18:23	triddell	now mentions you're approach
18:23	triddell	your that is
18:24	technomancy	cool
18:24	stuhood	if you don't add a ':state true' clause to gen class, do you still get a 'this' parameter added to your method calls?
18:24	hiredman	erm, I believe so
18:25	technomancy	triddell: I'm really _not_ trying to just drive hits to my blog, honest. It just comes off that way. =)
18:25	hiredman	wait
18:25	hiredman	stuhood: this is only in proxy
18:25	triddell	technomancy: just want the best info out there... that was my intent with the tutorial
18:25	hiredman	for gen-class the this parameter is explicit
18:26	triddell	technomancy: gotta run though... just wanted to give you and other an fyi
18:26	technomancy	cool; have fun w/ your new blog
18:26	triddell	technomancy: thx ;-)
18:26	hiredman	like, a function backing a two arg method needs to have arity 3
18:26	stuhood	hiredman: explicit, in that i have to ask for it by saying :state true?
18:26	stuhood	gotcha
18:26	hiredman	no
18:28	rsynnott	technomancy: so that you can make a VAST FORTUNE on google ads? :)
18:28	technomancy	rsynnott: you've found me out!
20:13	mrsolo	hmm aquaemacs doesn't have locate-dominating-file ....
20:59	dbudworth	Just checking to see if my IRC client is functioning, no one is saying anything...right?
20:59	ctdean	right
20:59	dbudworth	ahh, good. thought i was crazy (or this mac irc client was)... (usually it's me)
21:00	ctdean	Just the time and day I think, not much going on
21:06	dbudworth	any idea how to get the classpath set when using emacs-starter-kit + slime + swank-clojure? the username.el in .emacs.d is loaded too late it seems to take effect
21:06	ctdean	nope, sorry. I always set the classpath by hand
21:06	dbudworth	trying to go through the "programming clojure" book, but when using slime I can't get the classpath to include the book root dir (which is needed for things like (use 'examples.foo)
21:07	dbudworth	you can set it inside clj? is there a way to dynamically add to the cp?
21:07	durka42	yes and no, there is add-classpath but it's discouraged
21:07	ataggart	highly
21:08	dbudworth	normally, wouldn't even need it. but for this particular case (book examples) they make a big assumption about your working dir (or at least having the root be in the cp)
21:09	ataggart	skipping over and just using the book's repl.sh made life easier
21:09	ataggart	though I haven't gotten too far into the books code
21:10	dbudworth	yeah, that was the other choice. just use a regular shell. just thought slime was neat. IntelliJ's clojure plugin actually has a repl (and the standard Idea project classpath setup).. just wanted to use emacs' fanciness
21:11	ataggart	being neither an emacs user nor lisper, having to deal with emacs as well as learn the language was just too much to bear
21:11	ataggart	now I just need to figure out how to kill the IntelliJ REPL
21:12	dbudworth	there's a "delete repl" or something like that, that kills it... checking
21:15	dbudworth	tools -> add / remove reply (option-command-a/option-command-m on a mac)
21:15	dbudworth	s/reply/repl
21:15	ataggart	ah thx
21:16	ataggart	running doseq on an infinite fibonacci seq tends to bog things down
22:53	mattrepl	anyone been using c.c.error-kit?