#clojure – 2008-10-30

2008-10-30

00:00	Chouser	sure. I'm off to bed. Have a pleasant evening.
00:01	_sohail_	you too
01:17	scgilardi	I'd like to get a list of files in a directory in classpath. I know a classpath-relative path but not an absolute path. It occurred to me to use findResource, but (.findResource (clojure.lang.RT/baseLoader) "clojure/contrib/sql/sql.clj") returns nil at the same time as (.getResourceAsStream (clojure.lang.RT/baseLoader) "clojure/contrib/sql/sql.clj") returns a stream. That confuses me.
05:45	AWizzArd	Moinsen
05:49	asbjxrn	Something changed in the macro code recently?
05:54	asbjxrn	I used to have a macro (defmacro foo [& funcs] `(bar ~(fn [] ~@funcs)))
05:54	asbjxrn	That now throws an exception: "Can't embed unreadable object in code: "
05:55	H4ns	asbjxrn: does not look right to my (untrained) eye anyway
05:55	H4ns	the first ~ unquotes the whole (fn...) form, so the additional unquote is invalid and the error message makes sense.
05:56	asbjxrn	True that.
06:00	asbjxrn	It did end up doing what I wanted it to do, though. Haven't managed in the new svn release.
06:01	H4ns	what do you want that to do?
06:05	asbjxrn	Well, "bar" puts that func into a hash, later in a rendering function I pull that function out again (after binding some variables like mouse position), and evaluate it.
06:06	H4ns	why do you unquote the (fn...) form?
06:06	asbjxrn	The trick is that if I call (foo (line 0 0 mouseX mouseY)), mouseX and mouseY is not valid outside the rendering function.
06:06	asbjxrn	Good question. I wrote this quite a while ago.. :)
06:07	asbjxrn	That's my only defense :-/
06:07	jdz	asbjxrn: are you sure you veed macros at all?
06:07	jdz	need even
06:07	asbjxrn	Yes, otherwise mouseX and mouseY will be evaluated when I call foo.
06:08	jdz	well, that's because you are using macros...
06:08	jdz	asbjxrn: i'm pretty sure that what you do can easily be done using functions...
06:09	asbjxrn	I'm pretty sure it can't :)
06:09	jdz	you just stuff appropriate functions in your map and then call them, passing all necessary parameters
06:10	jdz	the less context-dependent your functions are the happier you will become in the future. trust me.
06:11	asbjxrn	Imagine (on-mouse-click (background 0) (stroke 200 100 100) (line 0 0 mouseX mouseY))
06:11	jdz	imagine (on-mouse-click [mX mY] (background 0) (stroke 200 100 100) (line 0 0 mX mY))
06:12	H4ns	or (on-mouse-click (background 0) (stroke 200 100 100) (line 0 0 (:mouseX context) (:mouseY context))
06:13	H4ns	i fully agree that capturing random names in macros is generally bad style.
06:13	jdz	H4ns: i'd still prefer my approach :)
06:14	H4ns	jdz: less extensible, requires knowledge of the function signature at the call site.
06:14	H4ns	jdz: what if there is a mouseZ available? change all the callers? not nice.
06:14	jdz	not really
06:14	jdz	imagine (on-mouse-click [mX :mouseX mY :mouseY] (background 0) (stroke 200 100 100) (line 0 0 mX mY))
06:15	asbjxrn	H4ns: How do you stop (:mouseX context) from being called when you call (on-mouse-click)?
06:15	H4ns	jdz: different, but repetetive
06:15	H4ns	asbjxrn: #(...)
06:15	jdz	i consider magic context ugly. but that may be just me.
06:15	H4ns	jdz: it is not magic, it is just context.
06:15	asbjxrn	My on-mouse-click is a macro that puts the commands in place.
06:16	jdz	asbjxrn: i'm trying to convince you that on-mouse-click does not have to be a macro
06:16	H4ns	asbjxrn: well. remove the first tilde and don't listen to us.
06:16	asbjxrn	Think scripting language.
06:16	asbjxrn	(def panel 100 100 (background 0))
06:16	H4ns	asbjxrn: first rule of using macros: don't
06:17	asbjxrn	(draw-fun (line-width 10) (ellipse 0 0 mouseX mouseY))
06:19	asbjxrn	jdz: Two problems: in draw-fun I want to be able to combine functions.
06:20	asbjxrn	jdz: I have many variables, mouse positions, key pressed, size of window etc.
06:20	H4ns	asbjxrn: what prevents you from creating an anonymous function with #()?
06:20	asbjxrn	To require the function to accept all the variables is messy.
06:20	H4ns	asbjxrn: yes - that is why i would propose using _one_ instead of multiple special variables, and name the special variable according to the convention
06:21	H4ns	asbjxrn: that way, you'll just script your gui in clojure rather than inventing something new, with funny capturing semantics
06:23	asbjxrn	Not quite as clean, though...
06:23	jdz	i claim that making functions depend only on their parameters is a good thing.
06:24	H4ns	jdz: it is generally a good thing, which does not automatically make passing context in special variables a bad thing. one just needs a good reason to do so.
06:24	jdz	that's what makes them parallelization-friendly
06:24	H4ns	jdz: convenience can be such a good reason.
06:24	H4ns	asbjxrn: i'm not sure if i want to discuss "clean"
06:24	H4ns	oh, well, yes, i am sure. i do not want to discuss "clean"
06:25	asbjxrn	:-)
06:25	jdz	yeah, i'd consider my proposed approach much cleaner than asbjxrn's :
06:26	asbjxrn	Sure, from a theoretical point of view.
06:27	jdz	asbjxrn: nope, on the most practical point of view.
06:27	jdz	which is code maintenance
06:28	asbjxrn	I wrote this inspired by processing.
06:28	asbjxrn	I wanted something similar for the user point of view.
06:28	asbjxrn	Which means the user first sets up a window with (setup 100 100)
06:29	asbjxrn	then uses macros like (draw (background 0) (line 10 10 100 100) (whatever))
06:29	asbjxrn	and (on-mouse-move (line pmousex pmouseY mouseX mouseY))
06:30	asbjxrn	And things immediately gets updated in the window.
06:30	jdz	there are only two things that change when mouse is moved. and making those things explicit is a good thing.
06:31	jdz	or even more -- the code that responds to mouse move event only wants two things from the event, and depends only on those two.
06:31	jdz	so only those two should appear in the code
06:31	jdz	if code depends on more, well, then make those explicit, too.
06:32	jdz	i think CLX does it this way
06:33	H4ns	jdz: if i understand things right, asbjxrn wants to create something that is easy to use for beginners, failing to recognize that beginners will eventually become experts and then recognize that with the apparent simplicity comes bad design.
06:33	jdz	asbjxrn: so you either set your goal to be as close to Processing API as possible, or make it distinct enough so people don't come up with wrong expectations.
06:34	jdz	H4ns: this is not the first time when our understanding is very similar. have i seen you on #lisp maybe? :)
06:34	H4ns	jdz: not entirely impossible :)
06:35	jdz	yay, double negatives.
06:35	asbjxrn	H4ns: there are limitations of course. You can't override the pre-defined variables. And yes, simplicity is the goal here.
06:36	jdz	asbjxrn: the point is thas this simplicity is superficial, and it comes at a cost.
06:36	H4ns	think php
06:36	jdz	and it breaks down when users become advanced enough
06:37	jdz	and you lose flexibility
06:45	asbjxrn	H4ns: Just using anonymous function worked
06:47	asbjxrn	Can't remember why I ended up with that extra ~ back when
06:50	asbjxrn	Actually, that was only in my setup macro which requires extra stuff (size of window mostly) . my draw/mouse/keyboard stuff just uses anonymous functions.
06:56	Chousuke	http://wordwarvi.sourceforge.net/ :D
07:00	Chousuke	(maybe someone needs to make an emacs version)
08:24	Lau_of_DK	Afternoon guys
08:25	Lau_of_DK	Ive noticed that JEditorPane reads Html just about as well as I read Russian - What are my alternatives?
08:26	duck1123	alternatives for reading HTML?
08:26	Lau_of_DK	For rendering it in a Swing app
08:27	duck1123	ahh, I've never much used Swing, so I'm no help
08:28	jdz	there is something that can render html
08:28	jdz	i'm sure i saw an exapmle of it in the mailing list or somewhere related to documentation lookup
08:28	jdz	with code!
08:29	H4ns	javax.swing.text.HTMLEditorKit should do
08:30	Lau_of_DK	I'll try to look into it
08:30	asbjxrn	H4ns: You just beat me to it.
08:30	Lau_of_DK	Thanks guy
08:30	Lau_of_DK	s
08:31	asbjxrn	A google found this somewhat old, but maybe interesting lead:
08:31	asbjxrn	http://today.java.net/pub/a/today/2004/05/24/html-pt1.html#The_Swing_HTMLEditorKit
08:32	asbjxrn	Couple of links in the comments as well.
08:33	cemerick	Lau_of_DK: you can hook in a native browser component to render HTML in a swing app. JDIC is the name of the corresponding, project, I think.
08:35	duck1123	so using a component like JLabel doesn't work very well
09:55	Lau_of_DK	asbjxrn, cemerick : Thanks! :)
10:02	gnuvince	http://lispy.wordpress.com/2008/10/25/lisp50-notes-part-vi-the-future-of-lisp/
10:02	gnuvince	That posts almost makes a savior out of Rich :)
10:09	abrooks	gnuvince: BTW, nice blog post. Is there an email address where you'd like me to send feedback? (Note, this channel is logged and indexed by Google so anti-spamify accordingly...)
10:10	abrooks	gnuvince: "nice blog post" == your post from last night.
10:11	AWizzArd	Lau_of_DK: is Jambi enough to bring Qt closer to Clojure?
10:12	gnuvince	abrooks: vfoley@gmail.com
10:12	duck1123	I really hope that talk makes it onto blip.tv
10:13	AWizzArd	duck1123: what talk?
10:13	gnuvince	abrooks: I'm interested in all types of comments. I'm not a native English speaker, so notes on the language are fine, notes about the Clojure style are fine, etc. Chouser already suggested that I look into line-seq, which is really nice.
10:13	duck1123	the lisp50 talk
10:13	gnuvince	AWizzArd: the Lisp50 talk.
10:13	duck1123	everythink I've heard about it says it was great
10:15	Chousuke	it sucks though that in most of the recorded talks it's impossible to hear the questions asked :/
10:15	abrooks	gnuvince: Thanks. I'll get back to you later tonight (GMT-5).
10:15	abrooks	tomhickey did a nice job of transcribing the questions for the Boston Lisper's talk.
10:16	gnuvince	abrooks: thanks a lot.
10:22	Chouser	gnuvince: your English was perfect.
10:23	Chouser	gnuvince: native language is French?
10:23	gnuvince	Yes.
10:24	Chouser	have you considered blogging about Clojure in French? I imagine there are plenty of non-English speakers who might be interested in Clojure but have far fewer resources at hand.
10:28	leafw	does line-seq close the reader and thus releases the file handler when done?
10:28	leafw	i.e. when all lines have been read.
10:29	leafw	and does it cache lines already read? I guess it does--would be nice to have a version that doesn't.
10:30	Chouser	if you don't hang onto the head of the seq, I don't think it'll keep the lines in memory.
10:31	Chouser	line-seq does not close the file, you have to open and close it yourself.
10:32	gnuvince	Chouser: I do want to make a blog post to present Clojure in French. I don't think I'll do the tutorial in French though, most good French programmers speak English.
10:32	Chouser	rhickey has mentioned before that there's a general issue of cleaning up after seqs over stateful objects (like open files) -- right now it's all manual and therefore error-prone
10:32	Chouser	gnuvince: ok
10:33	gnuvince	But a high level introduction to the language is definitely in my plans.
10:37	Lau_of_DK	AWizzArd, http://paste.lisp.org/display/66213 <-- This combined with Jambi brings Qt a whole lot closer, but there is still considerable ground to cover
10:38	AWizzArd	Does it look like a few days-weeks of work? Or more in the area of 5+ months?
10:39	Lau_of_DK	I cant really say. So far it looks like open roads ahead, with some Qt exploration involved. But 'the unexpected' might pop its head up more than a few times. But I'll let you know once I make some head-way
10:40	wwmorgan_	what's wrong with Jambi?
10:40	Chouser	Isn't Jambi just another Java lib? Can't you just use it?
10:41	Lau_of_DK	Chouser, there's no 'just' about it from where Im standing
10:42	Lau_of_DK	Anyway, Im away for a few minz/hours, if you have the time, please lisp-paste an example of a Qt GUI app, designed in 'designer' running from Clojure, I'd be ever so happy :)
10:42	kib2	gnuvince: I would be glad to read your tuts, even in French !
10:44	gnuvince	kib2: you speak French?
10:44	kib2	I'am French, and I'm currently learning Clojure
10:44	gnuvince	Cool
10:45	gnuvince	New Now Know How...
10:45	gnuvince	Have you ever been in #programmeur?
10:45	kib2	never...worth a look ?
10:46	kib2	I've started something to write a Clojure tutorial (a Qt app, but in Python sorry :)) : http://www.flickr.com/photos/kib2/2984219379/sizes/l/
10:54	leafw	question about namespaces
10:54	leafw	if I was to add or overwrite a function in an existing namespace,
10:55	leafw	what would one do: (in-ns 'inspector) ... then define whatever function, which would be then under inspector namespace?
10:55	gnuvince	It's not a bad place, some knowledgeable people, mostly C and C++ programmers, I'm the only one with any interest in functional languages. It's about 2/3 Quebecers, 1/3 European with the occasional guy from Morocco
10:55	leafw	that didn't work.
10:56	scottj	I'm trying to use the sql contrib with MS SQL Server. I downloaded sqljdbc.jar and put that in the classpath, now I' defining my db variable and I set :classname to "com.microsoft.sqlserver.jdbc.SQLServerDriver" and :subprotocol to "sqlserver" but what should :subname be? and where do I put the server name, user name, password, and database name?
10:57	Chouser	leafw: in what way did it not work?
10:58	leafw	java.lang.Exception: Unable to resolve symbol: binding in this context (NO_SOURCE_FILE:1) at clojure.lang.Compiler.analyze(Compiler.java:3814)
10:58	leafw	and so on.
10:58	leafw	I guess my interpreter messed it up. Never mind
10:58	leafw	will have to come up with a better strategy to catch clojure's output for print into a REPL
10:58	leafw	I am currnelyt using (binding out <any entered text here> )
10:59	wwmorgan_	leafw: in general, prefer the ns macro to explicit in-ns, use, etc
10:59	wwmorgan_	in your case, the ns macro would have done the clojure/refer for you
11:00	Chouser	but the inspector namespace should already have names like "binding" in it.
11:01	duck1123	scottj: I know for mysql, I had to set :subname to "//localhost/dbname"
11:01	Chouser	scottj: I don't know what you mean by "db variable". My one experiment with db work in clojure, I used java.sql.DriverManager/getConnection
11:02	duck1123	and then just add in :user and :password, anything it doesn't recognize gets added as query params
11:02	leafw	wwmorgan_: so you'd use (ns 'inspector) instead
11:02	wwmorgan_	chouser: hmm. Perhaps he was doing (in-ns 'inspector) instead of (in-ns 'clojure.inspector), or he hadn't loaded inspector.clj
11:02	Chouser	wwmorgan_: oh! both excellent points.
11:03	wwmorgan_	leafw: (ns clojure.inspector (:use (clojure inspector))) works for me
11:06	leafw	thanks.
11:37	brainus	Hello there. Why wouldn't {:['a' 'b'] 2} work? I am trying to use a small vector a key.
11:38	Chouser	'a' doesn't make sense. you can use either a string "a" or a character \a
11:39	gnuvince	brainus: {["a" "b"] 2}
11:39	Chouser	oh, and :[] doesn't make sense. a vector is a fine key [\a \b]
11:40	brainus	ah, excellent. thanks.
11:40	djpowell	If I wanted to create map keys that have metadata, then I can't use keywords, but would functions like this be reasonable: (defn #^{:doc "A persons first name"} field-first-name [o] (o field-first-name)) - it would then work as both (field-first-name obj) and (obj field-first-name) like keywords do
11:41	djpowell	I guess a macro would make it easier to create such fn keywords
11:42	Chouser	djpowell: interesting idea!
11:43	Chouser	I'd never thought of it. I guess you're right -- it would work.
11:43	Chouser	the map would print kinda ugly.
11:43	djpowell	yeah, that is true
11:43	duck1123	then you just have to make a macro to make it easier to create those
11:45	djpowell	i hadn't thought about them not printing nicely though, that would suck
11:50	Chouser	you could add a new print-method to handle fns that prints just their name if they have some kind of metadata flag. :-)
11:51	Chouser	This is all to put a bit of documentation on a map key?
11:51	Chousuke	can't you put the documentation on the map itself?
11:53	lisppaste8	Chouser pasted "QtJambi with UI via designer, for Lau_of_DK" at http://paste.lisp.org/display/69450
11:54	Lau_of_DK	Chouser, will you please stop by DK so I can give you a kiss ?
11:56	Chouser	it could clearly use a couple helper functions, but I don't see any huge multi-week issue lurking there.
12:05	djpowell	hmm, actually, regarding the fns as keywords idea, you can get the same functionality just by using symbols, and it prints nice too
12:07	djpowell	(def #^{:doc "A persons last name"} field-last-name) ; (def m1 {'field-last-name "Dave"}) ; (m1 'field-last-name)
12:10	djpowell	I hadn't realised that invoking a symbol calls get on its argument
12:11	Chouser	djpowell: yeah, just like keyword. Looks funny to me, though.
12:12	Chousuke	you can also do (def field-last-name 'field-last-name) and then (field-last-name m1) :P
12:14	Chouser	Chousuke: oh, that's wild.
12:14	Chousuke	kind of circular. a var whose value is the symbol that names the var.
12:17	drewr	djpowell: You don't need semicolons. :-)
12:18	djpowell	ha, i know
12:18	djpowell	Chousuke: a bit like my earlier example, a function whose definition calls get on a map with the function as the key
12:19	Chousuke	well, a symbol appears to be such a function. :)
12:20	Chouser	plus this lets you redef field-last-name later, to completely screw with access to your map
12:20	Chousuke	heh
12:25	Chousuke	doing the (def foo 'foo) makes foo basically a keyword without the :. it evals to itself.
12:26	djpowell	yeah, but it is mutable, which isn't really desirable
12:31	Chousuke	Hm, well, t's basically an accessor function for the map. Most functions are redefinable -- whoever does so for anything important is in no position to complain, though.
12:33	Chouser	the lookup will go through an extra step of indirection (the var) compared to using a literal symbol or keyword.
12:50	djpowell	i was thinking that the var would be in the map, but it will resolved to the symbol at the point of assoc-ing, and get-ing
13:20	kib2	I've made a Pastebin for Clojure : http://clojurepastebin.appspot.com/
13:33	djpowell	Hmm, is it possible to create a macro that expands to something like: (def #^{:doc x} y 123) or equivalent?
13:35	djpowell	I'm thinking that I might be getting into trouble with #^ being reader syntax, but I can't use with-meta, because def requires an actual literal symbol as it's first argument
13:41	djpowell	I can't see how to generate '(def #^{:doc "test"} x 4)' with a macro because I can't quote #^, and '(def (with-meta (symbol "x") {:doc "test"}) 4)' isn't valid syntax for def
13:55	wwmorgan_	djpowell: check out the source of def.clj in clojure-contrib to see how they do it
13:59	djpowell	ah, thanks
14:17	AWizzArd	Was there something experimental that allows me to have something like a callback function that is called after an agent has finished?
14:20	Chouser	AWizzArd: there's (agent state validate-fn)
14:20	AWizzArd	oki, let me check if that is what I had in mind
14:20	Chouser	but that's not supposted to have side-effects
14:24	AWizzArd	What could happen if it had site-effects?
14:25	Chouser	AWizzArd: dunno, but it's a mis-use of the feature.
14:25	Chouser	oh, you might actually want add-watch
14:26	AWizzArd	ah yes, that was it
14:37	AWizzArd	Right now there is nothing like (list-all-watchers-of agent) yes?
14:42	Chouser	looks like watchers is private and I don't see an accessor
14:42	Chouser	of course you could have a convention of tossing each watcher into the metadata somewhere or something.
14:43	AWizzArd	right
14:43	AWizzArd	Chouser: btw, what is the watcher supposed to do? Why do I add a watcher and a callback? Wouldn't the callback be enough?
14:44	AWizzArd	The callback functions has 3 parameters of which one is the watcher which could in principle be called from within the callback
14:45	Chouser	AWizzArd: hm, not sure. I've never used add-watch.
14:47	Chouser	AWizzArd: perhaps it's so you can re-use the same callback function for multiple watchers?
14:47	AWizzArd	that could be possible.. but still the question stays what those two guys will be doing
14:48	Chouser	the callback is a fn, the watcher appears to be just any old value you want.
14:48	AWizzArd	The role of the watcher is not so clear to me right now.
14:48	AWizzArd	Hmm yes, the watcher could be any 1st class object it seems
14:48	Chouser	It's used as an id, a handle for use when you remove for example
14:48	gnuvince	Chouser: I've updated my blog post draft with the comments you made. Using line-seq made the program more succinct and easier to explain.
14:49	Chouser	gnuvince: ok, great.
14:51	gnuvince	I'll wait to hear from abrooks tonight before I post.
14:52	cemerick	rhickey: did you have any reaction of note to my suggestion w.r.t. user.clj? http://groups.google.com/group/clojure/browse_thread/thread/6951a19912adfb8a
14:54	rhickey	cemerick: NB is being overly pedantic there, and many have complained. The idea behind user.clj is to be pretty easy, getting involved in nested classpath could negate that. These just first thoughts, I haven't decided anything yet
14:59	cemerick	rhickey: Yeah, I agree on both points. I was thinking that perhaps a .clojure file in the home directory would be a good possibility (which would also break the illusion that user.clj is a good place to put startup initialization code, etc)
15:14	AWizzArd	Btw, the callback function that you add with (add-watcher agent watcher callback) does not need to have three parameters. As this runs in the same thread as the function we sent to the agent it means that agent is bound already correctly.
15:37	AWizzArd	http://clojure.org/data_structures#toc81 says that ArrayMaps will maintain keys in order. But when associng/conjing more data to it might make it become a hash-map.
15:38	AWizzArd	So, what is the 'maintains key order' part then?
15:38	AWizzArd	Would not any map that stays unchanged keep its order?
15:41	Chouser	compare (hash-map :a 1 :b 2 :c 3) and (array-map :a 1 :b 2 :c 3)
15:41	Chouser	array-map guarantees that a seq over it will get keys in the order you gave when you constructed it. Not so with hash-map.
15:43	AWizzArd	Tree Maps for example stay sorted even when I assoc new stuff onto it.. that's why I was wondering
15:45	Chouser	yes, but that's in sorted order not necessarily original order. compare (sorted-map :c 1 :b 2 :a 3) and (array-map :c 1 :b 2 :a 3)
15:46	AWizzArd	Sure, I understand the difference. I just thought that array maps will keep the order even when you assoc new elements later
15:51	Chousuke	maybe clojure is trying to save you from doing stupidly inefficient things with the map :/
15:52	drewr	Hm, cast doesn't do what I thought.
15:52	Chouser	cast does hardly anything.
15:53	drewr	I'm getting an interface back from a factory, but I need the concrete class.
15:53	Chouser	you can't have an instance of an interface.
15:54	Chouser	you can use (class ...) on it to see what it really is.
15:54	drewr	I'm getting a com.sun.org.apache.xerces.internal.dom.ElementImpl, but I need to cast it to a org.w3c.dom.Element.
15:56	drewr	At least I think so.
15:56	Chousuke	is Element the interface? or what.
15:56	Chouser	Have you tried just using it?
15:57	drewr	I'm trying to .appendChild on a DocumentImpl and it says the node can't be inserted there.
15:57	drewr	From what I can determine, HIERARCHY_REQUEST_ERR occurs when the node isn't the right type.
15:57	drewr	Yes, Element is the interface.
15:57	drewr	Here's the code I'm trying to clj-ize: http://www.rgagnon.com/javadetails/java-0511.html
15:59	drewr	Not wholesale, just trying to mimic the xml creation for a different purpose.
16:02	Chouser	drewr: don't you need an Element instead of a Document?
16:02	AWizzArd	And btw, why xml? ;-)
16:03	AWizzArd	You can store your data trees directly as s-expressions
16:03	Chousuke	drewr: can you show the code you have now?
16:04	lisppaste8	drewr pasted "xml generation" at http://paste.lisp.org/display/69465
16:05	drewr	AWizzArd: True, but I'm not sure I'll be able to use the reader to read it back.
16:06	Chouser	drewr: that worked for me
16:06	drewr	Hm.
16:06	drewr	Ah, I get that error when I try to append another.
16:07	AWizzArd	drewr: the Clojure reader has no side effects... unlike CLs reader it does not intern stuff that it reads
16:08	drewr	Chouser: And then xml is #=(com.sun.org.apache.xerces.internal.dom.DocumentImpl. "[#document: null]")
16:08	drewr	Why null?
16:09	Chouser	drewr: you can only have one element in a document
16:09	Chouser	that element (the "document element") can have any number of children
16:09	drewr	Ah, good call.
16:09	Chouser	so trying to add a second element to the document is failing for you
16:10	Chouser	(.getDocumentElement xml) shows the one element you added
16:10	Chouser	not sure what the "null" is about -- that's the Java object's toString method producing it.
16:11	ReplRat	Is there a JSON reader and printer?
16:11	drewr	ReplRat: I've played with the json-lib, and it's OK.
16:12	ReplRat	drewr: where is it? i didn't see it on Google.
16:12	drewr	But it didn't serialize java.sql.Timestamps correctly.
16:12	drewr	http://json-lib.sourceforge.net/usage.html
16:13	ReplRat	ah. I keep forgetting to look for Java libs instead of Clojure libs.
16:13	drewr	I should be able to attach a custom processor to the JsonConfig, but I lost interest by that point.
16:17	abrooks	I'm trying to transform a list of lists of three items ((1 2 3)(4 5 6)(7 8 9)...) into three lists ((1 4 7 ...)(2 5 8 ...)(3 6 9 ...)).
16:17	abrooks	I need a chart visually showing some of the seq transform functions.
16:18	abrooks	My brain gets stuck trying to remember them all.
16:18	drewr	That's a great idea.
16:18	abrooks	Ah... Hm. I could do this with lazy-cat.
16:19	Chouser	apply map list
16:19	Chouser	(apply map list foo)
16:20	abrooks	I tried thinking through this with (apply map list foo) but it didn't work in my head. Maybe my brain is broken.
16:21	gnuvince	Chouser: crazy trick!
16:21	abrooks	It works but I still am not thinking about it right.
16:21	gnuvince	I tried to find how to do exactly this last weekend.
16:21	abrooks	Chouser: Thanks. :)
16:21	gnuvince	I was toying with (apply #(map list %&) xss)
16:22	gnuvince	Didn't work<
16:22	Chouser	abrooks: I'm beginning to think a flowchart or something like it might work as well as the grid we were trying to build.
16:22	Chouser	for many of these tricky problems, there are actually not many tools that will work.
16:23	AWizzArd	If you can wait from time to time for cgrand you can get often extremly nice solutions :-)
16:23	Chouser	for example, trying to talk through multiple lists in parallel -- pretty much just "map" I think. "for" won't do it (it nests instead). most of the other seq functions only take one seq.
16:23	Chouser	AWizzArd: heh, exactly.
16:25	Chouser	so with map, you now have the right numbers, but they're args not a list. I've tried to use "identity" in such circumstances, but of course identity only wants one arg. "list" or "vector" do what you want.
16:25	Chouser	and finally you need apply if you're given a list of lists so that map can get at them.
16:30	abrooks	Chouser: A flow chart! Nice.
16:31	abrooks	Chouser: A seq transform expert system! :-D
16:31	Chouser	right
16:32	Chouser	"is your input a single seq, or multiple" "is your input seq made up only of seqs" ...
16:32	Chouser	but since an actual expert system of flow chart would get bogged down in ridiculous details and corner cases, I'm thinking perhaps a blog post.
16:33	abrooks	Does your data structure have a spinal chord? -> Chordates...
16:33	gnuvince	SPINAL TAP!
16:33	abrooks	er.. cord.
16:33	abrooks	gnuvince: Heh!
16:35	abrooks	Chouser: You bring up another point that I had sort of been thinking of which is sort of a catch-phrase list. parallel-lists -> [maps], folding -> [partition, for], nesting -> [for], etc..
16:36	abrooks	I guess that's sort of what we were trying to do in the spreadsheet but this notion was allowing for looser defined categories.
16:37	Chouser	I'm sympathetic with the idea that the spreadsheets categories might be too narrow.
16:38	abrooks	I think the fundamental taxonomy of the operations is too subtle to be useful. Going with a small handfull of generalities probably starts you in the proper direction.
16:42	AWizzArd	Do we have the enclojure developer here?
16:50	Chouser	that whole team is apparently swamped until after the election.
17:04	Pupeno	Hello.
17:04	Pupeno	Is there any particular moment when setting swank-clojure-extra-classpaths has an effect?
17:11	AWizzArd	Does (seq col) create a fresh list of all items in col? Or does it use some internal tricks on the java side to produce something that for me as a user looks like a list? I ask because seq returns extremly fast, and it seems to be not lazy.
17:12	Chouser	seq never copies any underlying collection. Usually it creates a new object that acts as a view on some other object.
17:13	AWizzArd	Okay, so this is what I meant by "trick"
17:16	Chouser	a notable exception is PersistentList, which itself implements ISeq. So calling seq on a list just returns the very same list.
17:17	AWizzArd	yes
17:18	Chousuke	vectors don't seem to implement ISeq :/
17:18	Chousuke	is there a reason for that?
17:20	Chouser	Yeah, it wouldn't be natural. But you can call seq on a vector and get a APersistentVector$Seq
17:23	gnuvince_	What's the significance of the $?
17:23	kotarak	Nested class
17:24	Chouser	In Java source code that looks like APersistentVector.Seq, but APersistentVector is a class not a package so the internal name uses a $ instead of a dot
17:25	Chouser	you see it in some exceptions, in .class file name, and in Clojure.
17:26	ReplRat	Is there a Clojure wiki that anyone can edit?
17:26	Lau_of_DK	How do I test i a symbol has previously been declared?
17:27	Chouser	ReplRat: wiki link on clojure.org
17:27	wwmorgan_	Lau_of_DK: (resolve 'foo)
17:27	Lau_of_DK	wwmorgan_, thanks
18:05	Chousuke	hmm
18:07	kotarak	sosososo
18:08	Chousuke	I'm trying to figure out a neat way to implement a version of partition that keeps the remainder, but my best (working) attempt so far uses reverse which isn't optimal :/
18:09	ReplRat	would it be possible (or desirable) to implement a condition/restart system like CL's in closure? I'd like, for example, to say what happens when a undefined symbol is evaluated.
18:09	Chousuke	hm, I should be more careful too... 41884 java 176.7% 36:43.44 20 555 207 77M 37M 87M 259M
18:19	gnuvince_	Chousuke: something like this?
18:19	gnuvince_	user=> (my-partition 4 (range 10))
18:19	gnuvince_	((0 1 2 3) (4 5 6 7) (8 9))
18:21	Chousuke	gnuvince_: yeah
18:21	gnuvince_	here's the code
18:21	gnuvince_	<mini-flood>
18:21	gnuvince_	(defn my-partition [n xs]
18:21	gnuvince_	(when (seq xs)
18:21	gnuvince_	(lazy-cons (take n xs)
18:21	gnuvince_	(my-partition n (drop n xs)))))
18:21	gnuvince_	</mini-flood>
18:22	Chousuke	I'm pretty sure I tried that :/
18:22	Chousuke	I wonder what I did wrong
18:22	gnuvince_	Don't beat yourself too much, it was probably a little detail you forgot.
18:23	gnuvince_	That happens to me all the time.
18:28	AWizzArd	well, humans suck at programming
18:28	Chousuke	ah, I know what I did
18:28	AWizzArd	It's time we let our computers do that for us :-)
18:28	Chousuke	I forgot the (when (seq coll) ...
18:29	gnuvince_	Chousuke: ah :)
18:30	gnuvince_	AWizzArd: you saw the movie "Eagle Eye", haven't you?
18:30	AWizzArd	hmm, maybe
18:30	AWizzArd	I usually forget movies fast after I saw them
18:31	gnuvince_	AWizzArd: it's in theaters now, it's about an AI that goes rogue
18:31	gnuvince_	(how original...)
18:36	AWizzArd	Maybe we all are AIs that go rogue from time to time. I personally plan to use Clojure extensively for AI programming.
18:37	AWizzArd	I should try to make a bot which can outperform wwmorgan_ who also seems to be some kind of bot. You ask a question about what a function is called, and the moment you press enter you can already see his answer.
18:37	gnuvince_	AWizzArd: are you very busy at the moment?
18:37	AWizzArd	not very
18:38	gnuvince_	Would you mind reading a draft of a blog post I made on Clojure? It's the first part of a small tutorial, and I want to get input from the people here to make sure it's OK.
18:38	AWizzArd	sure
18:39	kib2	gnuvince : sure :)
18:39	gnuvince_	http://fornost.homeip.net:81/vince/clojure-comics1.html
18:39	gnuvince_	Here it is
18:39	gnuvince_	you can send comments at vfoley@gmail.com
18:39	cemerick	enclojure users: I just posted to the enclojure google group a rough patch to enclojure's head that adds support for multiple remote REPLs. If you are so brave as to try it, I welcome feedback/suggestions, mostly because I'm groping through the dark on a number of fronts in that context.
18:52	AWizzArd	hmm, apropos variables... when we have (def x 1), how much sense does it make to call x a variable?
18:53	wwmorgan_	sounds fine to me
18:54	AWizzArd	yes, to me also, because I am used to it
18:55	AWizzArd	although beginners could ask what exactly is variable in it
18:55	AWizzArd	maybe a beginner would suggest to call it a constant
18:56	wwmorgan_	I wouldn't call it a constant
18:57	AWizzArd	(def pi 3.1....) "The variable pi is used ...."
18:59	AWizzArd	Well, we need a name for the things that follow after def and variable sounds nice
19:02	kib2	gnuvince : ping
19:04	gnuvince_	pong
19:06	kib2	http://kib2.alwaysdata.net/tempo/gnuvince.html
19:06	kib2	more readable
19:07	AWizzArd	kib2: now only put it all into a frame with a width of 800px
19:07	AWizzArd	so that people with widescreen displays also can read it :-)
19:08	gnuvince_	kib2: I'll be posting it on Wordpress
19:09	kib2	AWizzArd: my tool does not do that for the moment, I don't want to modify it by hand :)
19:10	kib2	gnuvince : I'm going to sleep now, I'll read it in bed and give you a feedback tomorrow, ok ?
19:10	gnuvince_	kib2: sure thing.
19:10	kib2	See you
19:10	Lau_of_DK	AWizzArd, its not fully tested, but it seems that as of now, using the Qt-designer (and its standard widgets only, text-boxes, inputboxes, calendars all thats) you can design a form and run it from clojure, incl. hooking up slots/events.
19:12	AWizzArd	Lau_of_DK: this is good news... I am looking forward to hear what you will find out in the coming weeks about it. Perhaps it really is fully functional already. This would make especially you and a bunch of other people happy. And if not you might have very concrete info what exactly is not working as you wish.
19:16	Lau_of_DK	AWizzArd, hang on 3 minz, I'll show you something
19:17	AWizzArd	Lau_of_DK: one thing that would be very nice is a step-by-step tutorial that explains how to make a webstart application that you can simply click on a website and get a minimal Qt app that shows "Hello World".
19:19	AWizzArd	This would tell how to publish code that you wrote in Clojure so that other people can use it, it would explain how to make a minimal webstart application, and it would also give an example on how to do Qt with Clojure.
19:23	Lau_of_DK	Thats not too far out in the future
19:23	Lau_of_DK	Have you worked with their designer yet ?
19:24	AWizzArd	I have no idea what the designer is
19:24	Lau_of_DK	Ok, with this new stuff that Chouser cooked up, we can load ui's designed in the 'designer' directly in Clojure
19:25	AWizzArd	Lau_of_DK: you could download something like http://camstudio.org/ and put a little video on youtube
19:26	Lau_of_DK	In 1 minute, I'll show you how to build a webbrowser using the designer
19:26	Lau_of_DK	It also has tools for text-boxes with code-highlighting, calendars, video-renderers and so on
19:27	Lau_of_DK	http://www.bestinclass.dk/download/designer.mpeg <-- I appologize for the resolution, go fullscreen
19:31	AWizzArd	Thanks. The designer looks clean and professional.
19:32	AWizzArd	Now it would be interesting to make a .jar file that a user simply needs to doubleclick
19:32	Lau_of_DK	Its good stuff - So now once I clear up a little import problem, you can design a gorgeous crossplatform GUI in seconds, with powerful functionality, and drive it directly from clojure
19:32	Lau_of_DK	Thats not a problem
19:33	Lau_of_DK	The problem right now is just getting the full functionality of Qt into Clojure
19:33	AWizzArd	You can make a tutorial video, with spoken language available on youtube. This could explain it all step by step to total newbies. Some of them might be driven to Clojure by that.
19:34	AWizzArd	If it looks easy and colorful people will enjoy it. And hundreds of your watchers will send around their own programmed webbrowser to their friends :-)
19:35	AWizzArd	"Yeah, I made it. Ima progamer expert in Qt-Closhure"
19:35	Lau_of_DK	How about you handle the PR, and I'll put in some more work on the functionality :)
19:36	Chousuke	heh
19:36	AWizzArd	yeah, let's think about it
20:18	Lau_of_DK	AWizzArd, this is what you want right? http://dist.trolltech.com/developer/download/webstart/
20:18	AWizzArd	yes
20:19	AWizzArd	I tried that before
20:19	Lau_of_DK	k
20:19	AWizzArd	now only for your 100% Clojure example, a simple hello world
20:19	Lau_of_DK	k
20:38	sohail	Lau_of_DK, that mpeg.. that's not showing any clojure things is it?
20:46	Lau_of_DK	No, its showing the GUI of the designer. With the designer you design a nice form/window/dialog, and that window can be driven from Clojure
20:49	sohail	Lau_of_DK, I see
20:49	sohail	does qt jambi let you use anonymous classes for slots and stuff?
20:49	Lau_of_DK	yes, with a litle modding made possible by jamii, it actually does
20:49	Lau_of_DK	With this much code, you can load a seriously complex GUI
20:49	Lau_of_DK	(let
20:49	Lau_of_DK	[ ui (QUiLoader/load (QFile. "code-ui.ui"))]
20:49	Lau_of_DK	(.show ui)
20:49	Lau_of_DK	(.connect (.triggered (.findChild ui Object "action_Exit")) ui "close()")
20:49	Lau_of_DK	(QApplication/setStyle (QStyleFactory/create "Oxygen"))
20:49	Lau_of_DK	(QApplication/exec)))
20:50	Lau_of_DK	And it will render with Oxygen widgets, which are really pretty :)
20:50	Lau_of_DK	http://paste.lisp.org/display/66041
20:50	Lau_of_DK	With this, you can use the slots anonymously
20:51	sohail	that's cool
20:51	Lau_of_DK	yea its extremely cool
20:52	sohail	I wrote a qt binding for CL that was better but not very portable it seemed :-)
20:52	Lau_of_DK	Oh :) Feel free to paste it
20:52	sohail	well better when you used slots anyway... :-)
20:55	lisppaste8	sohail pasted "qtcl for Lau_of_DK" at http://paste.lisp.org/display/69479
20:56	sohail	Lau_of_DK, I much prefer you doing it for clojure though ;-)
20:56	Lau_of_DK	Dont worry I will, just looking for inspiration
20:57	Lau_of_DK	I'll have to read through it tomorrow though, we're coming up on 02:00 AM here, which means time for bed - Have a good one all
21:34	gnuvince_	What's this binding audit thing?
21:36	Chouser	audit?
21:37	gnuvince_	http://richhickey.backpackit.com/pub/1597914
21:39	Chouser	oh, that. He wants to change doseq, if-let, and such that do bindings to use vectors.
21:39	gnuvince_	(doseq [e coll] body)?
21:39	Chouser	exactly.
21:40	gnuvince_	ok
21:40	gnuvince_	What about condp and fcase that I keep hearing about?
21:40	Chouser	so that requires digging through boot.clj to make sure that every single one is covered.
21:41	Chouser	I don't think those bind any locals.
21:59	fbru02	hey all ! :) I have a newby question ! :)
21:59	fbru02	can i shoot them ?
22:01	gnuvince_	fbru02: shoot away, if somebody has the answer, they will answer.
22:05	fbru02	ok :) I programmed in python ruby c# and haskell but many of this problems I think it have to do much with lisp notation than with clojure in general but Im learnig clojure .... 1) (defn functioname [ parameter1 & parameter2] ) what does the & stnad for ? and 2) (let x (into #{} x)) #{} stands for creating a set ?
22:07	gnuvince_	1) the & indicates a rest parameter
22:07	gnuvince_	Since you know Python, here's something equivalent:
22:07	gnuvince_	(defn foo [a & b] [a b]) == def foo(a, *b): return [a, b]
22:07	fbru02	cool
22:08	gnuvince_	2) yes, #{} is the literal syntax for set.
22:09	danlarkin	gnuvince: actually (defn foo [a & b] [a b]) and def foo(a, *b): return [a, b] aren't exactly the same
22:09	danlarkin	they're very similar.. it's the same idea, but they are different
22:09	danlarkin	in the python one *b will be all arguments passed to foo
22:10	danlarkin	not just "the rest" like in clojure
22:10	gnuvince_	danlarkin: no, it'll be just the rest
22:10	gnuvince_	>>> def foo(a, *b): return [a, b]
22:10	gnuvince_	>>> foo(1,2,3,4)
22:10	gnuvince_	[1, (2, 3, 4)]
22:12	danlarkin	gnuvince_: oops... that's embarassing, I guess you're right.
22:12	gnuvince_	;-)
22:15	fbru02_	sorry
22:15	gnuvince_	uy... is that Uruguay?
22:15	fbru02_	yes !
22:16	fbru02_	nice country but we don't have many lispers here :(
22:20	fbru02_	thanx both one more thing and #(operator % (var1) var2) is syntax sugar for making a lambda function?
22:22	Chouser	yep: (fn [x] (operator % (var1) var2))
22:22	Chouser	note you can't use #() instead of a function like: (fn [x] {:foo x})
22:24	fbru02_	uh , I thouhgt that you didnt have to use put fn[x]
22:25	fbru02_	ah sorry now I get it : (fn[x] (op % (var1)var2)) == (fn #{op % (var1) var2)) right?
22:27	Chouser	no, (fn [x] (op x)) == #(op %)
22:27	Chouser	also no #{} and #() and #"" all mean different things
22:29	fbru02_	ah yes we discussed #{} before it was for making a set, what #"" means ?
22:30	Chouser	#"" is a regular expression literal
22:31	Chouser	these are explained at http://clojure.org/reader
22:31	fbru02_	ok thanks man, I'm goint to hit the bed now I think
22:32	Chouser	11:30 there?
22:32	fbru02_	1230 because we are on summertime
22:32	Chouser	ok. sleep well!
22:32	fbru02_	ok thanks mate , later ! :)
22:40	abrooks	gnuvince: I am wrapping up looking at your blog post. I started a while ago but got derailed when a friend called. :-/
23:30	wwmorgan	lisppaste8: url
23:30	lisppaste8	To use the lisppaste bot, visit http://paste.lisp.org/new/clojure and enter your paste.
23:33	lisppaste8	wwmorgan pasted "Good library to do this?" at http://paste.lisp.org/display/69484
23:36	bradbev_	I'd like to use zip_filter & xml from the contrib package, but keep getting Could not locate Clojure resource on classpath: clojure/contrib/zip_filter/zip_filter.clj. I've manually loaded zip_filter & clojure.xml.
23:37	wwmorgan	bradbev_: try starting clojure with clojure-contrib in your classpath
23:37	bradbev_	ah, OK...
23:40	Chouser	wwmorgan: sorry, I've got nuthin' Don't want to roll your own TCP protocol? :-)
23:41	wwmorgan	I don't want to have to worry about _anything_
23:51	abrooks	Heh. I hadn't seen this: http://www.lisp50.org/schedule/schedule/mccarthy_files/doing-it-wrong.jpg
23:52	bradbev_	thanks wwmorgan that works.
23:57	wwmorgan	bradbev_: check out the ns macro for a very clean way to handle almost all of your dependencies
23:58	bradbev_	wwmorgan: I saw that, but didn't click on to needing the classpath correct. I thought just loading the files from slime would get be the right stuff. Do the JAR files contain compiled Clojure code?