#clojure – 2009-06-24

2009-06-24

03:27	Lau_of_DK	Top of the morning gents
03:27	cgrand	morning Mr Lau!
03:50	frodef	so how do I specify the method class signature with proxy? I need one object with two methods with the same name but different argument classes..?
03:51	frodef	(mymethod [#^the-class arg] ...) seems not to be right?
03:59	hiredman	frodef: you don't
03:59	hoeck	frodef: proxy maps a clojure fn to each method-name, so you have to dispatch inside the fn
03:59	clojurebot	proxy is <Chouser> proxy teases with its ease of use, then suddenly betrays.
03:59	hiredman	what you do is you put a cond or similar inside the method
03:59	frodef	ah, ok. So both methods in the interface maps to the same-named fn. Thanks.
04:36	frodef	how do I ask wheter a value implements a certain interface?
04:36	frodef	(or is of a certain class?)
04:36	frodef	ah, instance?
04:37	frodef	..for classes, but not interfaces.
04:38	frodef	urgh, for interfaces too. I got the argument ordering wrong. sorry about the noise.
06:33	frodef	how do I round a number to nearest integer? e.g. (round 10 3) -> 3
06:33	frodef	..or (round (/ 10 3)) -> 3
06:35	sunwukong	round found in clojure.contrib.math works like your second example
06:37	frodef	ok, thanks.
06:43	AWizzArd	General question for your opinion: do you know/think that it is allowed to have a (clojure) program automatically gathering information from a website? For example look up automatically 3000 words in a dictionary?
06:45	sunwukong	imho legally: yes ; morally: depending on the actual server/amount of data
06:45	dhaya	AWizzArd: The same rules that apply for search engines crawlers apply. (robots.txt etc). Also, hitting the site without sufficient pause time, will likely get your IP banned.
06:55	AWizzArd	ah good, the robots.txt should help, thanks you two
08:36	rhickey	sweet, this is what's nice about being on the JVM. Had updated my os x java vm, now includes VisualVM...
08:37	rhickey	so I type jvisualvm at a prompt, VisualVM comes up, calibrates for my machine, show a gui, oh look, there's my (already running) repl session, connect, start getting monitoring, proifiling etc
08:40	rhickey	not as powerful as yourkit, but handy
09:02	Chouser	rhickey: I think you have enough earnings from Clojure T-shirts to offer a bounty for contrib.jar
09:02	rhickey	Chouser: heh, now I need to bribe, eh?
09:03	mblinn	well you could pay in t shirts
09:03	Chouser	bah, a couple dollars short, at least for some shirts.
09:03	Chouser	rhickey: just making you aware of your options. :-)
09:04	rhickey	thanks
09:04	Chouser	ah, it looks like any white T would be covered.
09:06	rhickey	hmm, I see "What would it take?" implies a bribe possibly
09:07	rhickey	Have been working on pre/post conditions
09:07	Chouser	cool
09:09	rhickey	something like:
09:09	rhickey	(defn foo
09:09	rhickey	#^{:pre [(even? x) (< x y)] :post [(not (nil? _))]}
09:09	rhickey	[x y] ...)
09:09	rhickey	eventually some mojo to make that:
09:09	rhickey	(defn foo
09:09	rhickey	[x y]
09:09	rhickey	{:pre [(even? x) (< x y)] :post [(not (nil? _))]}
09:09	rhickey	...)
09:10	rhickey	but still yielding the map as metadata on the arglist
09:10	Chouser	I've been telling people that Clojure will probably eventually have some kind of compile-time assertion system where "classic" static typing would be a subset. Is that roughly true?
09:10	rhickey	thus tools could find and display via metadata
09:11	rhickey	Chouser: that's one idea, built on some type of built-in logic lang like datalog/prolog
09:11	Chouser	yeah, ok. That was my impression.
09:11	rhickey	would be a hybrid of checker and analysis tool
09:12	rhickey	one point on the post conditions is how to label the return value (_ above)
09:12	Chouser	runtime pre/post is good too of course. Do you imagine it being used mainly during testing and turned off during production?
09:12	rhickey	options are _, or the fn name (would require it be named)
09:13	rhickey	Chouser: that depends on the app, so there will have to be some flags
09:13	Chouser	_ elsewhere has come to mean "I don't care" ... might be pretty confusing to overload that meaning here.
09:13	rhickey	considered assert no/yes/condiionally (supply a var)
09:14	rhickey	Chouser: agreed, _ means don't care everywhere else
09:14	achim	how about making % readable outside #(...) for such things (similar to unquote)?
09:14	rhickey	could use a fixed name, like 'ret'
09:14	rhickey	achim: I have though about that
09:14	Chouser	achim: I was wondering that too
09:15	rhickey	one problem is that it would allow a lot of errors to flow through and become 'I don't understand %', also would let people do (let [% 42] ...)
09:16	rhickey	right now when you see % you know you are in an anonymous fn def
09:16	Chouser	people can already do (binding [map filter] ...) Just because it's bad doesn't mean it has to be forbidden.
09:16	rhickey	agreed
09:17	rhickey	one other point was possible destructuring of return value for post
09:17	Chouser	hmmm
09:17	rhickey	else :post [(let [[x y] %] ...)]
09:18	rhickey	ok if only one test, tedious if more
09:19	Chouser	right, but giving a spot in which to name the rtn value would solve both the naming and destructuring at once.
09:19	rhickey	Chouser: that's something different altogether, seems like a hassle
09:19	Chouser	:rtn rtn :post [(< 5 rtn 10)]
09:20	rhickey	I don't like it separate from post
09:20	Chouser	yeah, that was to avoid :post [rtn (< 5 rtn 10)]
09:20	rhickey	exactly
09:21	rhickey	but :post [aname ...] is the best I could come up with, just irregular
09:23	rhickey	either name is always required, or must be a symbol/vec/map binding form
09:23	rhickey	will work until we have lists as destructuring forms :)
09:26	Chouser	I don't think 'always required' is so terrible, but changing from binding to test exprs without sentinel in a single vector's a bit tricksy
09:26	rhickey	agreed, not done anywhere else
09:27	lpetit	why not a short and a long form ?
09:27	Chouser	[:pre (< 5 x) (even? x) :post [rtn] (< 5 rtn 10) (odd? rtn)]
09:27	Chouser	eh.
09:27	achim	might type-based preconditions eventually be a way to avoid boxing/unboxing of numbers? i.e. if the args to a function are constrained to be ints, would it be possible to generate bytecode that took unboxed ints as arguments?
09:28	rhickey	achim: no
09:28	Chouser	I was thinking having the binding form always in a vector might help it stand out, but that doesn't really look much less confusing.
09:28	lpetit	short form takes directly a vector of forms
09:28	lpetit	long form takes a map with :rtn (taking possibly a binding) , :tests (or something else) taking the vector of forms
09:29	rhickey	Chouser: plus the result is still a to-be-parsed bag
09:29	Chouser	not much point if the long form is longer than (let [[x y] %] (and ...))
09:29	rhickey	lpetit: I'd really like to avoid that kind of thing. ns/require/use are the most complicated parts of Clojure for that reason
09:30	lpetit	rhickey: I understand
09:30	Chouser	now's not the time to discuss, but I'd love to require removed and 'use' simplified. I think it can be done.
09:32	lpetit	having the output follow a given "destructuring form" may convey enough information on itself to deserve not being mixed with other post conditions.
09:33	frodef	is there some variable somewhere that limits the size of stacktrace that gets printed?
09:33	rhickey	I'm going to work on the presumption that multi-test postconditions requiring destructuring will be rare
09:33	frodef	I have a stack overflow that I find it hard to find the source of.
09:34	Chouser	frodef: you might look at clojure.contrib.stacktrace
09:35	lpetit	So maybe having along with :pre and :post some :rtn-struct (I'm really bad at naming things :-(.
09:35	lpetit	If no :rtn-struct (or some really better name!) is provided, then use % or the function name or whatever you come up with as a default value to reference the return value in the post conditions
09:35	lpetit	If :rtn-struct is provided, then the symbols (either a simple one to name the result, or more complex ones when destructuring is leveraged) are provided for each form in the :post vector ?
09:35	clojurebot	http://clojure.org/data_structures#toc10
09:36	frodef	Chouser: ok, thansk
09:38	lpetit	so the simple case : :post [(pos? %)]
09:38	lpetit	the moderate complex case :ret-struct [k v] :post [(not (nil? k)) (not (nil? v))]
09:38	lpetit	note that :ret-struct could then be used to externally document the structure of the return value. Maybe I don't like that so much, because we do not separate whether the destructuring is used for documentation or for not DRYin the post-condition code ...
09:39	lpetit	In the same time, the post condition code serves as documentation ....
09:40	Chouser	lpetit: the docs point is interesting -- very similar to how args are used now: destructuring for practical as reasons, but by default included in the docss.
09:42	frodef	hm.. these lazy lists are no fun debugging, are they.. :)
09:43	Chouser	frodef: can be a bit tricky. if you can handle a dorun temporarily, that sometimes helps.
09:44	lpetit	Chouser: maybe just the name :ret or :rtn instead of :ret-struct could be sufficient : it would document if anything is guaranteed by the function in terms of structure (even a single symbol is an explicit information that nothing is guaranteed, which is an indication)
09:44	frodef	Chouser: doall should do the same, no?
09:45	lpetit	But maybe it is too early and overlapping with the general problem of how to optionally expose type information
09:45	Chouser	frodef: well it de-lazy's your seq. Might be unacceptable depending on why your seq is lazy, but if it's ok it may shorten your stack trace and make things happen in a dynamic context that is less surprising.
09:46	Chouser	lpetit: except it's so nicely symmetric with input args.
09:51	weissj	what is the clojure equivalent of mapcar?
09:52	Chouser	weissj: I think just 'map'
09:52	lpetit	Chouser: yes, indeed. So you like the idea ?
09:53	Chouser	lpetit: well, I like the idea of having a place to explicitly declare return value destructuring for use in docs and post conditions. Haven't seen a syntax I like yet though.
09:55	Chouser	(defn [a b c] :rtn [a] ...) except that looks like it might return the value of arg a, which is of course completely wrong.
09:55	lpetit	:returns ret-name :post [(pos? ret-name) (even? ret-name)]
09:55	lpetit	or :returns [key val] :post [(not (nil? key)) (pos? val)]
09:55	lpetit	inserted in the map along with :pre , :docstring ... keys
09:56	Chouser	lpetit: I don't think that's terribly, but rhickey already said he didn't like it separated from the :post exprs.
09:56	Chouser	terrible
09:58	lpetit	(defn foo #^{ :pre [(even? x) (< x y)] :returns [k v] :post [(not (nil? k)) (> v y)] } [x y] ...)
09:59	lpetit	Chouser: well, the args names are separated from the :pre, and that seems not to be a problem, though :-)
09:59	Drakeson	assume (f l) -> [l1 l2]
09:59	Drakeson	how can I partition a list by iteratively applying f to the current list, spitting out l1, and keep l2 as "current list"? is there a way better than loop?
09:59	lpetit	,(doc partition)
09:59	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."
10:00	lpetit	oh no
10:00	Chouser	Drakeson: example?
10:01	Chouser	I don't really understand what are in l1 and l2
10:01	lpetit	,(doc split-with)
10:01	clojurebot	"([pred coll]); Returns a vector of [(take-while pred coll) (drop-while pred coll)]"
10:03	Drakeson	assume I call it partition-with. (partition-with #(split-at 3 %) (range 1 10)) -> [(1 2 3) (4 5 6) (7 8 9)]
10:05	Chouser	ahh
10:06	Chouser	returning a vector means non-lazy, so it can be built on reduce
10:06	frodef	increasing the jvm's stack size seems to help me.. consequently I suspect that the zip-filter.xml uses stack O(n) to the XML input size?
10:07	Drakeson	Chouser: laziness > vector, assume it returns a list then.
10:13	Drakeson	,lisppaste
10:13	clojurebot	java.lang.Exception: Unable to resolve symbol: lisppaste in this context
10:13	Chouser	,url
10:13	clojurebot	java.lang.Exception: Unable to resolve symbol: url in this context
10:13	Drakeson	~paste
10:13	clojurebot	lisppaste8, url
10:13	lisppaste8	To use the lisppaste bot, visit http://paste.lisp.org/new/clojure and enter your paste.
10:14	lisppaste8	Drakeson pasted "partition-with" at http://paste.lisp.org/display/82424
10:14	Drakeson	now, that is not equal to some other function we already have, right?
10:16	Chouser	Drakeson: I don't think so.
10:16	Drakeson	thanks
10:16	Chouser	for some cases, contrib.seq-utils/partition-by might suffice, but it's doing something a bit different.
10:17	Drakeson	I stole it from partition-by
10:17	Chouser	oh, ok.
10:17	Drakeson	(modified it a bit)
10:17	Drakeson	btw, I need that function for parsing.
10:18	Chouser	I think partition-by could be written using split-with and your partition-with
10:32	lpetit	http://clojure.org/lazy says "lazy-seq goes at top level of lazy sequence function" , and also "lazy-seq and delay both perform closed-over local clearing on the tail call of their body", so my question is : could there be a problem with the pasted partition-with code ? if not, are there corner cases where not placing lazy-seq as the top level form of lazy sequence function could have memory...
10:32	lpetit	...problem ?
10:39	lpetit	?
11:45	rhickey	Drakeson: that code is not fully lazy
11:46	Chouser	btw, someone pointed out that reduce on range is slower in chunked than master.
11:47	Chouser	I had to chain 2 or 3 more chunked operations before the chunking was a win over the Range object.
11:47	rhickey	Chouser: I know, I took out the IReduce special paths in order to see what matters, reduce on range being a nice demo but not typical
11:47	Chouser	right
11:48	tsdh	Hi. I'm currently transforming some clojure code into an eclipse projects to make it appealing to my colleagues.
11:48	rhickey	just added reduce on the chunks themselves, with other tweaks today (reduce + (filter even? (map identity v))) almost 2x as fast as yesterday (in chunks), and 5x as fast as pre-chunks
11:49	tsdh	In one clojure app, I use some images in the GUi. Now I have the code in src/foo/bar/baz.clj and the images in icons/*.png. But I don't have a clue howe to reference them...
11:50	tsdh	(ClassLoader/getSystemRosource "icons/a.png") returns nil. Adding several ../ in front doesn't make it happy, either.
11:50	Drakeson	how would you serialize an object into a file? would you use spit and pr-str ?
11:51	stuartsierra	Drakeson: yes, or open a writer and use pr
11:52	Drakeson	how would you get rid of print-level and print-length temporarily?
11:52	Drakeson	,print-level
11:52	clojurebot	30
11:52	stuartsierra	(binding [print-level nil, print-length nil] ...)
11:52	tsdh	I think in Java I would use getClass().getResource(relativePathFromThis), but that has no equivalent in clojure, afaikt.
11:52	Drakeson	aaah, that's it, thanks.
11:55	tsdh	Oh, using simply (ImageIcon. "icons/a.png") works. Well, most often the simplest solution is still the best.
11:55	tsdh	;-)
12:09	baetis-fly	Can anyone explain when you'd want to use definline?
12:09	opqdonut	for performance reasons i guess
12:10	Chouser	if you want to take or return primitives in some cases, but allow your fn to be used in other higher-order cases as well.
12:11	baetis-fly	Let me be more specific. In compojure, there is a definline servlet which takes a function and creates a proxy servlet for the route. If I called (servlet) in the same namespace as my route (function) then i can do hot reloads when i redefine the function. When i call it from another namespace, that no longer works.
12:12	Chouser	baetis-fly: link to that code?
12:13	baetis-fly	Chouser: sure, one sec.
12:14	baetis-fly	http://github.com/lrenn/compojure/blob/4a2079d1a28cddcb174c4a7f650c6a70e3258f31/src/compojure/http/servlet.clj
12:16	baetis-fly	It's that "automatically updates if the routes binding is redefined" part that stops working when i move the servlet call into a different namespace than the route definition.
12:18	Chouser	I'm not sure why that's not a macro. Clearly there's something I'm not getting here.
12:19	baetis-fly	Chouser: That's what I thought. Which is why I asked what definline was used for. I'm just not sure why James is doing it that way. I'll goto the source. Many thanks Chouser.
12:34	combasa	morning
12:35	rhickey	what's the best way to push a local branch to github and have it be tracked? github's recipe here: http://github.com/guides/push-a-branch-to-github seems to leave it untracked
12:36	rhickey	last time I had to delete local after push, then branch --track, seems wrong
12:36	Chouser	rhickey: you mean you want plain "git push" and "git pull" to operate on that branch?
12:37	rhickey	when in that branch locally, yeah
12:37	rhickey	that's how chunks is working
12:37	Chouser	oh, I see. I'm still learning how to use git against a git remote (instead of svn remote)
12:37	combasa	I wish I knew more about git, im just learning
12:38	Chouser	I've edited .git/config manually before, but I bet that's not right.
12:38	Chouser	or rather that there's something better.
12:38	Chousuke	use git config :P
12:39	rhickey	for chunks I did git push origin chunks, git branch -d chunks, git branch --track chunks origin/chunks
12:39	Chousuke	basically, you need to set configure branch.<name>.remote and branch.<name>.merge
12:39	rhickey	couldn't find a way to push with tracking
12:40	Chousuke	so git config branch.chunks.remote origin; git config branch.chunks.merge chunks
12:40	rhickey	Chousuke: I understand, but, ugh
12:40	Chousuke	actually, if the remote is origin, the first config is unnecessary
12:42	rhickey	this recipe seems oriented towards knowing you want a remote branch up front:
12:42	rhickey	git push origin master:refs/heads/some_branch
12:42	rhickey	git fetch origin
12:42	rhickey	git branch −−track some_branch origin/some_branch
12:42	rhickey	git checkout some_branch
12:46	Chousuke	git checkout -b branch origin/branch sets up tracking by default
12:46	Chousuke	hmm
12:47	rhickey	Chousuke: that's not the scenario
12:47	combasa	ya i was going to say wouldnt `git checkout -b mybranch master` make mybranch your current branch, then you could setup remote and push be pushing with that?
12:47	rhickey	local branch exists, want to create on remote with tracking
12:47	Chousuke	well, for that you'd need the two git config commands.
12:48	Chousuke	then just push
12:48	rhickey	using commands, not config file editing
12:48	rhickey	Chousuke: I get the config file method
12:48	Chousuke	as I said earlier, just: git config branch.chunks.remote origin && git config branch.chunks.merge chunks
12:48	Chousuke	could probably make an alias for that.
12:49	combasa	haven't tried but why not setup branches in their own directorys then you dont need multiple configs each repository would have its own, not sure how you'd setup a branch in a different directory though
12:52	combasa	I'm going to have to re-read `git help branch` again I see
12:53	Chousuke	you can't really have a branch in a different directory other than by cloning
12:54	Chousuke	but clones of local repositories are cheap, as git just uses hardlinks whenever it can
12:55	combasa	yeah I realised it was a dumb idea :P
12:56	combasa	actually that reminds me, I wanted to ask.. if I wanted to start looking into the clojure source where would be a good place to start?
12:56	Chousuke	which part of the source?
12:56	combasa	yes which part
12:56	Chousuke	I mean, the java or the clojure side? :)
12:56	Chousuke	core.clj is pretty easy to understand.
12:57	Chousuke	the java stuff... not quite. :P
12:57	combasa	I'll have a look there then
12:57	combasa	where would be a good java place to start?
12:58	Chousuke	I haven't looked at it much :)
12:58	Chousuke	I guess it depends on what you want to know.
12:59	combasa	is the goal to have it all done in clojure at some point?
12:59	Chousuke	well, most, anyway
12:59	Chousuke	but that's probably not going to happen very soon :/
12:59	combasa	well I don't think it really matters either way does it
13:01	Chousuke	hmm, interesting
13:01	Chousuke	there's a Seqable.java~be56ab81e88f8001494058a055089e982595c453 in my clojure source tree. in src/jvm/lang :P
13:01	Chousuke	looks like it's untracked.
13:07	amunite	hi all. i'm following http://yusupov.com/blog/2009/basic-clojure-setup-part-1/ to setup clojure in os x, but i cannot make it work. java is unable to find clojure.jar at all. any advice or clue?
13:08	combasa	do makes use .bashrc files? im on linux
13:08	combasa	mac's I mean
13:09	kotarak	When you use bash... then "yes" I suppos.
13:09	combasa	I see, maybe I'll just have a look at the guide first
13:09	Chousuke	by default, Terminal.app uses login as the shell, so it uses .profile
13:09	Chousuke	but if you use bash then bashrc will matter too.
13:13	combasa	hmm that guide smells a little funny to me
13:16	technomancy	it's pretty old
13:16	technomancy	well, sort of old.
13:17	technomancy	I guess the move to git is recent enough not to call it old. =)
13:26	Jomyoot	Is there a web framework for clojure?
13:27	combasa	I believe enclojure is a web framwork, but I haven't looked at it yet
13:27	slashus2	~compojure
13:27	clojurebot	compojure is http://github.com/weavejester/compojure/tree/master
13:28	slashus2	~ring
13:28	clojurebot	ring is http://github.com/mmcgrana/ring/tree/master
13:28	combasa	ah right, compojure
13:28	Jomyoot	anything close to rails?
13:28	combasa	whats enclojure?
13:28	slashus2	A netbeans plugin for clojure.
13:28	combasa	ah right
13:28	Jomyoot	how is performance of enclojure vs. scala?
13:44	slashus2	Could count be made chunk aware?
13:58	quidnunc	cgrand: Can you give me an example of how to use the text-node selector?
14:00	cgrand	quidnunc: at last :-)
14:02	cgrand	(select nodes [:abbr :> text-node]) should return a seq of string
14:03	quidnunc	cgrand: Sorry, different time zone + work makes it hard for me to catch up with you.
14:04	cgrand	and I'm sorry that today I have to run pretty soon
14:04	quidnunc	cgrand: Me too :)
14:04	cgrand	quidnunc: mail me
14:05	quidnunc	cgrand: :abbr is a placeholder for a tag name?
14:05	cgrand	yup but it's also a real tag-name
14:05	cgrand	have to go
14:05	quidnunc	cgrand: Thanks
14:09	lisppaste8	slashus2 pasted "chunk count" at http://paste.lisp.org/display/82446
14:09	slashus2	What do you all think of this?
14:13	slashus2	There are probably some improvements that could be made to the code, but you get the idea.
14:14	cemerick	wow, almost a 2x speedup.
14:14	slashus2	yup
14:14	cemerick	should I expect the chunked stuff to make all seq operations faster in general (map, filter, etc)?
14:14	slashus2	Range has taken a pretty significant performance hit from generating a chunked seq though.
14:14	Chouser	(count (range ...)) is constant time on master
14:16	slashus2	Chouser: I looked at the code in RT and it looked like it incremented a counter.
14:16	Chouser	slashus2: what you've got seems reasonable. I wonder if chunk producers other than range would see much benefit.
14:17	slashus2	Chouser: I guess range's performance will increase later..
14:18	Chouser	slashus2: RT.count uses a counter if the collection is not Counted.
14:18	Chouser	If it's Counted, it asks the object to count itself -- for things like vectors and Range, this is constant time.
14:20	slashus2	I see.
14:20	slashus2	I guess we could also make chunks Counted...
14:21	Chouser	but on the chunked branch, range does not use Range, so your chunk-count has benefit there.
14:24	Chouser	(let [v (vec (range 1e6))] (time (chunk-count v)))
14:24	Chouser	it's interesting to compare that with core/count.
14:25	Chouser	oh, nm
14:25	Chouser	that's just showing that chunk-count should check for 'counted?'.
14:26	Chouser	(time (chunk-count (map identity (range 1e6))))
14:26	Chouser	I think that's closer to what I meant to test. Looks like chunk-count still helps quite a bit.
14:27	Chouser	slashus2: I think rhickey is accepting chunked versions of seq-processing functions.
14:30	rhickey	slashus2: counting non-counted things is a waste, making faster not that important
14:31	rhickey	slashus2: range is work in progress, will be at least as fast as it was
14:31	slashus2	Point taken.
14:31	slashus2	Just experimenting
14:31	rhickey	Counted implies constant-time, chunked seqs can't generally beCounted, though some specific ones can
14:32	Chouser	I thought writing a chunking 'iterate' might be fun.
14:33	rhickey	Chouser: you mentioned that before, one issue is the 'chunked' lazieness, might be ok for some usages but not others
14:33	Chouser	mm... good point.
14:33	rhickey	don't want to break those all important fib benchmarks :)
14:33	Chouser	heh
14:33	Chouser	same thing with 'repeat' I suppose.
14:34	rhickey	repeat can cache the thing
14:34	rhickey	not really doing more work like iterate would
14:34	Chouser	sorry, 'repeatedly'
14:34	rhickey	ah
14:35	Chouser	(repeatedly #(.readLine f))
14:36	rhickey	we'll have to see what people want most with chunks in place, I know for me I care much more about not fully realizing intermediate results than I do never moving ahean more than one, what matters is that there be a recipe for those that want the latter
14:37	rhickey	there will have to be a seq1, e.g. to stream singular values from something that would otherwise be chunked
14:37	rhickey	but iterate1, repeatedly1... I don't know
14:38	Chouser	well, repeatedly's specifically for side effects -- much more likely one extra step to be undesirable.
14:38	Chouser	not sure about iterate
14:39	rhickey	also there's no inherent indexed structure behind readLine, and I/O time is likely going to dominate seq overheads
14:40	rhickey	as will any other non-trivial work
14:41	rhickey	the chunked seqs most benefit the very lightweight work people often want to do with HOFs, but usually get penalized there vs loops
14:46	rhickey	name of flag for controlling pre/post asserts? (when false turn into no code at all)
14:47	Chouser	check-conditions
14:47	Chouser	:-P nm.
14:48	rhickey	matbe to toggle all assert?
14:48	rhickey	maybe
15:17	ctdean	It's been a long while since I updated my clojure.jar. Is there a version of clojure-contrib that matches clojure_1.0.0 or should I just pull the bleeding edge for both?
15:18	Chouser	ctdean: afaik, master contrib currently still works with clojure 1.0
15:19	ctdean	Is that just svn update from my clojure-contrib dir? or is there a better place for me to download it?
15:20	Chouser	contrib and clojure have moved to git
15:20	ctdean	aha, didn't know contrib had move also. Thanks so much
15:21	Chouser	http://github.com/richhickey/clojure-contrib/tree/master
15:21	ctdean	Perfect, got it
15:23	ctdean	All that worked great.
15:25	rhickey	pre/post conditions are up - feedback welcome
15:30	rhickey	assert false nils-out asserts
15:30	Chouser	% as post arg
15:32	Lau_of_DK	Hi everybody - I just want to let the people watching ClojureQL know that we're sorry that development has been so slow for the past 6 months - We are now up and running at full speed and have 2 working demos, 1 for MySql, 1 for Derby! We are now moving on to implementing JOINS, and that will but us at the very edge of version 1.0 :)
15:33	Chouser	Lau_of_DK: great!
15:33	rhickey	Lau_of_DK: cool - link?
15:34	kotarak	http://github.com/Lau-of-DK/clojureql
15:34	kotarak	Don't look too closely. ;)
15:34	Lau_of_DK	http://github.com/Lau-of-DK/clojureql/tree/master
15:34	Lau_of_DK	oh :)
15:38	Lau_of_DK	Sidenote: We are implementing dbms-specific routines in backend/derby.clj for example. If anybody would like to contribute patches for PostgreSql, Oracle, etc, it would be greatly appreciated :) We are currently targeting MySql and Derby exclusively.
15:47	Jonathan-Smith	are there any tutorials on how to properly structure/build a clojure project?
15:47	Jonathan-Smith	for example if I have multiple source files with different name spaces, how do i tell clojure to load them in a certain order
15:49	markcol	You can take a look Stuart Holloway's Lancet project that goes with the book "Programming Clojure". The sources are on github at http://github.com/stuarthalloway/lancet/tree/master
15:49	ctdean	Also the http://clojure.org/libs is reference page about this subject
15:52	Jonathan-Smith	cool, thanks
17:01	bpattison	is there a function that returns a list of string delimited by line breaks? I tried (re-split #"\n" lines) but it throws away lines that only have a line break in them, i.e. empty string
17:02	bpattison	I also tried (line-seq lines) but lines is a string and not a rdr
17:02	Chousuke	you could wrap it in a StringReader
17:03	kotarak	,(with-in-str "a\nb\c\n" (line-seq in))
17:03	clojurebot	Unsupported escape character: \c
17:03	kotarak	pfff
17:04	Lau_of_DK	Is the Google Code SVN no longer updated, with the adoption of Git ?
17:04	kotarak	,(with-in-str "a\nb\nc\n" (line-seq in))
17:04	clojurebot	java.lang.ClassCastException: clojure.lang.LineNumberingPushbackReader cannot be cast to java.io.BufferedReader
17:04	kotarak	-.-
17:06	ctdean	Yes, only github now
17:07	rhickey	svn, what's that?
17:07	hiredman	har har har
17:07	ctdean	,(re-seq #".*\n?" "abc def\n123\n\n789")
17:07	clojurebot	("abc def\n" "123\n" "\n" "789" "")
17:07	Chouser	bpattison: re-split shouldn't throw away empty strings.
17:08	Lau_of_DK	Cool :)
17:08	Lau_of_DK	rhickey: What changed your mind ?
17:08	ctdean	Almost right on the regex
17:09	Chouser	ooh, instance is called "new"?
17:09	Chouser	,(re-split #"\n" "a\nb\nc\n\nd\n\ne")
17:09	clojurebot	("a" "b" "c" "" "d" "" "e")
17:09	bpattison	(re-split #"\n" "l1\nl2\nl3\n\n\n") ---> ("l1" "l2" "l3") instead of ("l1" "l2" "l3" "" "" "") -- but I haven't update my clojure environment for a while
17:09	Chouser	,(re-split #"\n" "a\nb\nc\n\nd\n\ne\n\n\n")
17:09	clojurebot	("a" "b" "c" "" "d" "" "e")
17:10	rhickey	Lau_of_DK: it wasn't a changeof mind, it was finding the answers to a set of questions: hosting the code (github), tools (IntelliJ git support is good), collab services I could use for Clojure and commercial work (assembla)
17:10	Chouser	hm, trailing empty lines are tossed.
17:10	Lau_of_DK	rhickey: I see
17:10	ctdean	That is the perl split behavior
17:11	Chouser	huh. it seems rather unfortunate.
17:11	bpattison	no worries, now I know how it works - I'll just work around it
17:11	Chouser	,(re-split #"_" "a_b_cd__ef___g___h_")
17:11	clojurebot	("a" "b" "cd" "" "ef" "" "" "g" "" "" "h")
17:12	rhickey	Chouser: not sure about new, will need to be able to distinguish (new Classname ...) from (new instancename [bases] ...)
17:12	ctdean	try giving a limit, that might change it
17:12	Lau_of_DK	btw, rhickey, thumbs up on the pre/post conditions, thats awesome
17:12	rhickey	anyone try them yet? (pre/post)
17:12	ctdean	,(re-split #"_" "a_b_cd__ef___g___h_" -1)
17:12	clojurebot	("a" "b" "cd" "" "ef" "" "" "g" "" "" "h" "")
17:13	bpattison	ah! that worked
17:13	ctdean	yep, it's java copying the perl behavior
17:13	bpattison	works perfect now -- thanks!
17:15	itistoday	rhickey: i was wondering if there was any way to improve closure's api docs?
17:15	itistoday	rhickey: I come from newLISP, and I'd like to get to know Clojure too, but its api docs are far less easy to navigate and are much less indepth
17:15	rhickey	itistoday: improve how?
17:16	itistoday	rhickey: i.e. have functions grouped by area (string manipulation, list manipulation, file manipulation, etc)
17:17	Chouser	(defn re-split [p s] {:pre (instance? java.util.regex.Pattern p)} (seq (.split p s)))
17:17	itistoday	rhickey: this is how newLISP does it: http://www.newlisp.org/manual_frame.html
17:17	Chouser	then this should fail, right? (re-split "_" "a_b__c___d_")
17:18	rhickey	itistoday: newLisp has to implement a lot of fns Clojure doesn't, e.g. files, sockets etc
17:18	rhickey	but what Clojure does implement is divided up along the left, with sections like http://clojure.org/sequences
17:18	Chouser	ah, need another vector.
17:18	rhickey	that have lists of sequence fns
17:19	itistoday	rhickey: ah, OK thanks I'll try to get used to that
17:19	Chouser	so this works: (defn re-split [p s] {:pre [(instance? java.util.regex.Pattern p)]} (seq (.split p s)))
17:20	rhickey	itistoday: you'll also want to keep this handy: http://java.sun.com/j2se/1.5.0/docs/api/
17:20	ctdean	itiistoday: If you have an idea for a different layout, you could write a program to generate it. All the api functions are self documenting
17:20	ctdean	,(doc subvec)
17:20	clojurebot	"([v start] [v start end]); Returns a persistent vector of the items in vector from start (inclusive) to end (exclusive). If end is not supplied, defaults to (count vector). This operation is O(1) and very fast, as the resulting vector shares structure with the original and no trimming is done."
17:21	itistoday	rhickey: yeah, thanks, I know of that from way back when I used to care about Java :-p (now it looks like I'll be getting back into it because of Clojure)
17:21	Chouser	rhickey: I don't yet understand why new-new has to be done before c-in-c
17:21	itistoday	ctdean: thanks!
17:21	hiredman	erm
17:21	hiredman	new-new? I thought it was implement or whatever
17:22	rhickey	hiredman: or whatever
17:22	hiredman	,or-whatever
17:22	clojurebot	java.lang.Exception: Unable to resolve symbol: or-whatever in this context
17:24	hiredman	whatever is host in parens?
17:24	rhickey	Chouser: I'd like to have the final model in place, i.e. if we need classes with best perf we need Java right now, that doesn't make newnew a requirement, but I wanted to see what it would take
17:24	rhickey	we could use interfaces + proxy and have minimal code to change - proxy->newnew
17:24	clojurebot	proxy is <Chouser> proxy teases with its ease of use, then suddenly betrays.
17:25	Chouser	rhickey: ahh.. so if it turns out newnew isn't going to cut it, the work to make c-in-c hasn't been wasted yet.
17:25	rhickey	?
17:26	Chouser	aren't you saying that the reason to do newnew first is to prove it's a good model before rewriting it all in clojure?
17:27	rhickey	no, newnew is a good model, I'd like to use it when writing c-in-c
17:27	rhickey	I need newnew more than c-in-c right now, I still have to write classes or deal with perf issues, new range a case in point
17:27	Chouser	oh. yes, but I'd like to have c-in-c before trying to write newnew
17:28	hiredman	how metacircular
17:28	Lau_of_DK	I feel lost, what is this newnew and c-in-c, where do I go read ?
17:28	rhickey	agreed, I'd like to write newnew in c-in-c, and I need it yesterday :)
17:28	itistoday	how similar are clojure's sequences to SICP streams?
17:28	Chouser	Lau_of_DK: http://www.assembla.com/wiki/show/clojure/New_new
17:28	Lau_of_DK	Thanks
17:29	Chouser	c-in-c is just translating as much of clojure as possible from .java to .clj
17:29	rhickey	itistoday: same idea, but they (Clojure's) are much more powerful
17:29	itistoday	rhickey: i see that clojure has the delay/force functions, but they're not mentioned on the sequences page, are they used internally by the sequences?
17:30	Chouser	Lau_of_DK: my weak ugly and incomplete attempt at c-in-c: http://github.com/Chouser/clojure-compiler
17:30	rhickey	Clojure's seqs are defined in terms of interfaces, really a family of sequences, and are unified and interoperable with concrete seqs
17:30	Lau_of_DK	btw, where's clojure-script at Chouser ?
17:30	rhickey	the mechanism underneath is more involved then delay/force, but similar idea
17:30	Chouser	Lau_of_DK: contrib
17:31	rhickey	basically Clojure is full of production implementations of ideas you'll find in SICP
17:31	Lau_of_DK	Chouser: I meant in terms of maturity
17:31	Chouser	Lau_of_DK: but I have no intention of doing more work on clojurescript until c-in-c is done.
17:32	itistoday	rhickey: cool. still wondering about why delay/force is part of the api then, are they used somewhere else? or are they just there for the developer to use if they need to?
17:32	rhickey	itistoday: they are just useful library functions
17:32	clojurebot	They found no relationship between a programmer’s amount of experience and code quality or productivity.
17:33	Chouser	the move from lazy-cons to lazy-seq left clojurescript behind, and the thought of what would be required to keep it synced up with chunks, newnew, etc. is just exhausting.
17:33	itistoday	rhickey: k, thanks
17:33	rhickey	Chouser: while a direct attempt at cinc is possible, I have a large list of things I want to do differently
17:33	Lau_of_DK	I know the feeling, we just climbed that hill with ClojureQL :)
17:34	rhickey	e.g. not use reflection and concrete class instances during compilation, requires abstracting out type info provision
17:34	rhickey	but maybe there's a layered approach, I'll try to knock some of my notes into the wiki
17:36	itistoday	as Java is full of mutable objects, is there a document anywhere that discusses the considerations one should take if using it from a multi-threaded clojure program?
17:37	itistoday	or is at as simple as simply treating it as you would with java?
17:38	Lau_of_DK	rhickey: tried emacs' assembla-wiki-mode ?
17:39	rhickey	itistoday: coarsely, use Clojure data structures and facilities for your models, use java for I/O
17:40	itistoday	rhickey: if that I/O though might be one that's accessed by multiple clojure threads at a time.. what do you do? can you just wrap it in a ref and then use sync on it?
17:42	Chousuke	can't do IO in transactions
17:42	Chousuke	you could use agents
17:42	itistoday	Chousuke: ah, so have an agent that's responsible for the IO?
17:42	Chousuke	something like that.
17:42	rhickey	itistoday: IO from multiple threads it outside the scope of Clojure, there are separate protocols for each IO library (swing event thread, sockets stuff, db connection pooling etc)
17:43	itistoday	thanks, i'll stop bugging you guys with questions now and do some more reading :-)
19:08	JAS415	does the -> operator only work for functions that are associated with a name?
19:09	hiredman	nope
19:09	hiredman	but it isn't as pretty
19:09	hiredman	,(-> "foo" (#(.toUpperCase %)))
19:09	clojurebot	"FOO"
19:09	hiredman	you just double up on the parens
19:09	clojurebot	ΜΟΛΩΝ ΛΑΒΕ
19:10	hiredman	clojurebot: what?
19:10	clojurebot	what is java
19:10	JAS415	oh you have to do an extra set of parens
19:46	ozzilee	Compojure seems to include the path my application is deployed at when matching routes. Does anyone know if that's intentional?
19:47	ozzilee	i.e. if I deploy my app at "mysite.com/myapp", all of my routes have to start with "myapp/". Am I doing something wrong?
19:47	grrrt	"myapp" is your servlet's context path I assume
19:48	grrrt	if you don't want that, you could deploy the servlet under the ROOT context, but I'm not sure how to do that with compojure
19:50	ozzilee	grrrt: I can do that in tomcat, but I'd only be able to have one app per domain in the root context, correct?
19:51	grrrt	that sounds plausible yes
19:52	ctdean	Do you mean when using defserver? I'm not following.
19:53	ozzilee	ctdean: Using defroutes. (defroutes app (GET "" (str (params :)))).
19:53	ozzilee	(defservice app)
19:54	ozzilee	Compile that to a .war file, deploy it at context myapp, visit myapp/foo, and get "myapp/foo" in the response. To me, it should be just "foo".
19:55	ctdean	I see. I've never put my stuff in a .war, so I have no idea.
19:56	ctdean	The plain vanilla (e.g. from a repl) doesn't prepend a path
19:58	ozzilee	ctdean: Yeah, it's only an issue when deploying in a servlet container.
19:59	ctdean	Try the compojure mailing list, they're responsive
20:02	ozzilee	ctdean: I will eventually.
20:09	Drakeson	is it possible to insert break-points in function definitions in slime?
20:09	Drakeson	(e.g. the way you can C-u M-C-x a defun in elisp)
20:10	grrrt	Drakeson: I just tried that with cljdb - http://georgejahad.com/clojure/cljdb.html
20:10	grrrt	it did work
20:10	Drakeson	thanks
20:10	grrrt	no worries
20:17	JAS415	is it a common problem for clojure-dev to crash if repl output is too large?
20:17	JAS415	i keep having to force-quit eclipse it seems
20:38	Drakeson	Do you happen to know of a way to control firefox through java (and ultimately through a clojure repl)?
20:40	hiredman	Drakeson: are you just looking to webbrowser programaticly?
20:40	hiredman	htmlunit works pretty well
20:40	Drakeson	hiredman: not just that.
20:41	Drakeson	there is this javascript console (firebug) that is great. it would be even better if I could use a similar clojure repl to control and debug pages
20:53	durka42	there is mozrepl but i think that's javascript
20:54	durka42	but you don't use clojure to script pages (unless you're using clojurescript), so how would it be as useful as firebug?
20:55	Drakeson	durka42: if there was (or hopefully is) a way to interface to firefox through java, I could potentially have a clojure repl to do that instead.
21:00	rhickey	,(partition 3 1 nil (range 10))
21:00	clojurebot	java.lang.IllegalArgumentException: Wrong number of args passed to: core$partition
21:00	rhickey	hrm, new partition does:
21:00	rhickey	user=> (partition 3 1 nil (range 10))
21:00	rhickey	((0 1 2) (1 2 3) (2 3 4) (3 4 5) (4 5 6) (5 6 7) (6 7 8) (7 8 9) (8 9))
21:03	rhickey	seems to me partition with step 1 should never use the pad
21:03	rhickey	user=> (partition 3 1 [42] (range 10))
21:03	rhickey	((0 1 2) (1 2 3) (2 3 4) (3 4 5) (4 5 6) (5 6 7) (6 7 8) (7 8 9) (8 9 42))
21:09	Chouser	it should include (9 42 42) as well?
21:10	Chouser	shouldn't
21:10	rhickey	no, once it has produced a partition containing the last element of the coll it should be done
21:11	Chouser	hm... yes
21:11	Chouser	(partition 3 2 nil (range 5)) should end with (2 3 4)
21:12	rhickey	I've kicked https://www.assembla.com/spaces/clojure/tickets/120 back to Dimitry
21:22	Drakeson	~
21:22	clojurebot	what is java
21:22	Drakeson	~paste
21:22	clojurebot	lisppaste8, url
21:22	lisppaste8	To use the lisppaste bot, visit http://paste.lisp.org/new/clojure and enter your paste.
21:22	lisppaste8	Drakeson pasted "original partition" at http://paste.lisp.org/display/82474
21:23	lisppaste8	Drakeson annotated #82474 "modified" at http://paste.lisp.org/display/82474#1
21:26	lisppaste8	Drakeson annotated #82474 "better" at http://paste.lisp.org/display/82474#2
21:28	Chouser	if you use 'seq' as the opposite of 'empty?', then you can use if-let instead of repeating the drop expr
21:29	Drakeson	sorry, I didn't get it
21:30	Drakeson	which drop expression is repeated?
21:30	Chouser	(if-let [cont (seq (drop n s))] (cons p (partition n step pad cont)) (list (take n (concat p pad)))))
21:31	Chouser	oh
21:31	Chouser	nm.
21:31	Chouser	:-) ignore me.
21:31	Drakeson	:p
21:32	seths	I wish the api, special_forms, and kin pages on clojure.org were wiki pages
21:33	Drakeson	kin pages?
21:33	seths	it's frustrating when things like nthrest are mentioned in multiple places but don't exist
21:33	Drakeson	how is the web site managed? is it under git, by any chance?
21:34	Chouser	it's a wikispaces site
21:35	seths	must be private, wikispaces.com says this: Your search - Clojure - did not match any documents.
21:37	Chouser	seths: you're welcome to write up a list of errors and post it to the google group.
21:37	seths	good point
21:37	Chouser	it would be great if it were in git
21:38	moc`	Hi, sorry to interrupt. I am just starting out with Clojure and can't figure out why this code doesn't work: (map #(apply % '(1 2)) '(+ -)) => (2 2). I was expected (3 -1). Any ideas anyone?
21:41	Chouser	moc`: by quoting the list '(+ -) you're preventing the evaluation of each of those symbols
21:42	Chouser	you wanted a list of 2 functions, but instead you have a list of 2 symbols.
21:42	Chouser	if you use [+ -] instead, each of those symbols will be evaluated, and you'll have a vector of functions.
21:42	moc`	Chouser: OK, I get it.
21:43	Chouser	,('+ 1 2)
21:43	clojurebot	2
21:43	moc`	Chouser: Thanks. It was doing my head in.
21:43	Chouser	you're welcome. It's why we're here. :-)
21:47	seths	ok, Rich renamed nthrest to nthnext on Feb 17th 2009
21:48	seths	commit b8e333fb3437dca760f16136ed074a4dd463fe35
21:48	dreish	Extra confusing because a symbol acts as a function in the same way that a keyword does, taking a map as its first arg, and an optional not-found value as its second.
21:48	dreish	(That should have been to moc`)
21:49	dreish	But it doesn't throw an exception if the first arg isn't a map. It just returns the not-found value (or nil).
22:17	Chouser	anyone here used enlive on xml docs?
23:01	JAS415	gotta say
23:01	JAS415	i love memoization as a primitive
23:04	Chouser	anyone used enlive at all?
23:04	grrrt	yes I have
23:04	grrrt	just for tagsoup though
23:04	Chouser	well, that may still help me.
23:04	grrrt	I love the idea of enlive
23:05	Chouser	I just need a working example -- input html and 'select' call
23:05	Chouser	for what I'm doing me zip-filter would be sufficient, but I suspect enlive is better in every way. ...I just can't figure it out.
23:05	clojurebot	for is not used enough
23:05	Chouser	I've got my xml parsed into a format I think enlive wants.
23:06	Chouser	but (enlive/select xml [:description]) returns an empty seq
23:06	grrrt	I'll rummage through my clojure snippets for a bit, I must have something there
23:06	Chouser	in fact, anything I put in place of [:description] returns an empty list.
23:07	Chouser	eh, I but that means xml is in the wrong format.
23:07	Chouser	bet
23:08	grrrt	what format is it?
23:08	grrrt	I could just load a plain text file as a resource: (html-resource "templates/my-template.html")
23:09	Chouser	yeah, but I'm trying to avoid needing tagsoup, since I just need xml.
23:09	Chouser	if I were less stubborn this wouldn't be a problem
23:09	grrrt	ah sure, I see
23:09	Chouser	xml is fron (xml/parse foo)
23:09	grrrt	hm I think I have only ever used enlive's deftemplate macro
23:10	Chouser	(enlive/select (xml/parse input-stream) [:description])
23:12	Chouser	woo! got it
23:13	Chouser	(enlive/select [(xml/parse input-stream)] [:description])
23:13	grrrt	ah
23:28	holmak	Has anyone done much work with using Swing or another Java UI toolkit from Clojure?
23:28	holmak	More importantly, has anyone found a way to make it a tolerable experience?
23:28	grrrt	I'm working on something that makes using SWT easier
23:28	holmak	May I ask what approach you are taking?
23:29	grrrt	well (it's a work in progress still)
23:29	grrrt	I have created an easy way to specify SWT widgets in a tree
23:29	holmak	aha
23:30	holmak	(I had given some thought to this problem as well.)
23:30	grrrt	you can basically say things like (shell {:outlet :my-shell} (menu-bar (menu "File" (menu-item "New" {:shortcut \N})))) etc
23:30	holmak	I never realized how incredibly procedural Swing is until I used it from Clojure
23:30	grrrt	I know - I'm fighting SWT because everything has to happen in the UI thread
23:31	holmak	Well, I think that problem is tolerable if you just make a queue that you deposit UI calls into
23:31	grrrt	I have a separate namespace with functions that actually create the widgets
23:31	holmak	in Swing, there's SwingUtilities/invokeLater, of course
23:31	grrrt	they do (in-ui (Shell. (display)))
23:31	holmak	handy
23:32	holmak	So, here is the tricky problem I have -- how do you handle events, and how do you handle changing state of widgets?
23:32	grrrt	SWT uses events like selection, keydown etc
23:32	holmak	I'm not familiar with SWT
23:33	hiredman	http://gist.github.com/107140 <-- EDT macro is very useful
23:33	grrrt	I can respond to a menu selection by doing (menu "New" {:on-Selection (fn [evt] (println "Menu selected!"))})
23:33	holmak	Seems solid -- so how would you mutate widgets, like, to append to a text field?
23:33	hiredman	generally I have (future do stuff) in an event listener
23:33	hiredman	(to push stuff of EDT)
23:33	hiredman	off
23:34	grrrt	well, the structure of widgets I mentioned earlier
23:34	grrrt	all widgets support an :outlet option, such as {:outlet :my-label} for some text label
23:35	grrrt	the whole widget structure returns a map with all widgets that have an outlet defined
23:35	grrrt	if a button-push calls the "change-text" function, I can just do (.setText (:my-label outlets) "New Text")
23:36	holmak	nice
23:36	grrrt	because all UI stuff happens in the UI thread, this works, otherwise I could use agents (to go to other threads) or use in-ui
23:36	grrrt	When it's slightly more polished I'm planning to put my efforts online somewhere
23:37	grrrt	(I stole the term outlets from Mac OS X Cocoa)
23:37	holmak	It certainly seems like the Clojure community would benefit from a nice declarative GUI library/wrapper
23:37	grrrt	yes, it's tricky to combine functional programming with a gui
23:37	holmak	Your approach is similar to the thoughts I had
23:37	holmak	I started out thinking about Django templates
23:37	holmak	or really, and web framework template, take your pick
23:38	holmak	where you have little slots that you can plug your content in
23:38	grrrt	yes indeed
23:38	holmak	Because what I want to avoid above all else is keeping a big pile of widget objects around each with a dozen methods for mutating it
23:38	holmak	Sorry, that was a bit of a run-on
23:38	grrrt	:) no worries
23:39	holmak	The trick is that you don't want to recreate the GUI every update
23:39	holmak	unlike on teh web
23:39	grrrt	yeah, you need some kind of context to store your UI objects in
23:39	holmak	Right now I am doing horrific things with Swing in the name of getting another project done
23:40	grrrt	heh. I started out wanting to get a window going to do some graphics, then the "design the perfect world" syndrome kicked in
23:40	holmak	Ideally, you would have a pure Clojure data structure, like a map, that you could throw at your GUI "handle", and say, "update, GUI!"
23:40	holmak	and everything would drop into its slot
23:41	grrrt	hm, that sounds interesting
23:41	grrrt	I don't see why you couldn't do that
23:41	holmak	Eh, there has to be some kind of compromise between performance and declarativeness
23:41	hiredman	oh god
23:41	hiredman	foreclojure
23:41	hiredman	:\|
23:41	holmak	It's definitely an interesting problem
23:42	holmak	hiredman: where?
23:42	hiredman	the google group
23:42	grrrt	wow. just read the latest msg
23:43	holmak	hahaha
23:43	holmak	That's both witty and terrible
23:43	holmak	It's much harder to come up with good Clojure project names than, say, Python project names
23:43	grrrt	holmak: are you considering a situation where the UI is mostly updated in response to user actions?
23:44	hiredman	~Xiphojura
23:44	clojurebot	2009:Jan:29:16:03:17 <hiredman> I call Xiphojura
23:44	grrrt	or from a background process
23:44	holmak	"I'm making a spreadsheet, I'll call it, uhh, pySpreadsheet!"
23:45	holmak	grrrt: I don't really know where I was going with that thought. I didn't have a chance to think about it much.
23:46	holmak	But this entire thought process was triggered by trying to work with the Swing Tree widget.
23:46	holmak	Which is, in fact, a suite of about a dozen classes and a real nightmare.
23:46	hiredman	you could have an agent with a watcher
23:47	grrrt	hiredman: how does that work?
23:47	holmak	Oh, very interesting -- use the watcher to trigger changes, instead of validating changes?
23:47	hiredman	you alter the map in the agent, and the watcher updates the gui state based on the new values in the map
23:49	hiredman	would make for an interesting toolkit design
23:49	grrrt	hm. that sounds good
23:49	holmak	I should write these things down.
23:50	grrrt	neh just implement it
23:50	holmak	About the watchers, though: asynchronous madness!
23:50	holmak	If only we had a language well suited to dealing with massive concurrency...
23:51	hiredman	well, updates will be serialized anyway
23:52	hiredman	because the watcher will dump them on the edt
23:52	holmak	Oh I know. It's just that I would never devise a system using three parallel threads of execution in any other language.
23:52	holmak	But here, it practically makes sense!
23:53	hiredman	well, having gui stuff going on in multiple threads is a "dead dream" so you would need at least two threads anyway
23:53	grrrt	hiredman: does Swing's invokeLater work with "nested" calls?
23:54	grrrt	i.e. could you do (EDT (EDT (....)) ?
23:54	holmak	I feel like that would just invokeLater some invokeLaters
23:55	grrrt	my SWT equivalent would block if I tried that.
23:55	hiredman	grrrt: invokelater just ques up Runnables on swing's Executor
23:55	grrrt	ah right
23:55	holmak	hooray queues
23:55	hiredman	if EDT used invokeandwait or whatever it's called, then you would have a problem
23:55	grrrt	yeah
23:56	holmak	So, how do you feel about SWT? Either of you? I'm using Swing because it was closer, but I'm open to conversion.
23:56	grrrt	I don't know much about swing, can't really compare
23:57	grrrt	SWT seems reasonably straightforward, but I'd hate to do it in java
23:57	grrrt	5 lines of code for a simple menu item...
23:57	hiredman	swt is full of native code :(
23:57	grrrt	true
23:59	grrrt	but you can download or build it for many platforms
23:59	hiredman	would rather just depend on the jre