#clojure – 2009-02-12

2009-02-12

00:05	replaca	yeah, destructuring bind is one of the great lispisms
04:12	AWizzArd	clojurebot: max people
04:12	clojurebot	max people is 149
04:25	leafw	anybody can comment on the binding+import problem I just posted to the list
04:26	leafw	is this a clojure bug, or am I missing something.
04:34	hiredman	import works in side binding here
04:35	hiredman	user=> (binding [] (import '(java.io File)))
04:35	hiredman	nil
04:35	hiredman	user=> File
04:35	hiredman	java.io.File
04:37	leafw	that is case 1.
04:37	leafw	case 2 fails.
04:38	leafw	this fails: (binding [out bout] (import '(java.io File)) (println (File. "/home/albert"))
04:38	leafw	i.e. the import and the usage of the import all within the same binding block.
06:04	tomsw	Is there an inbuilt function to get the length of a list? I'm trying to write a function to shuffle a list and (afaik) for this i need the length
06:04	ayrnieu	,(count '(1 2 3))
06:04	clojurebot	3
06:07	AWizzArd	tomsw: maybe you should shuffle a vector
06:07	AWizzArd	Lists are not particularly important in Clojure.
06:18	alinpopa	tomsw: you can use size from java: (.size '(1 2 3))
06:19	alinpopa	I don't know if it's not slower than count .. but if you come from a java world you can use it (eg. you can use length for strings: (.length "abc") => 3)
06:20	alinpopa	.(.size '(1 2 3))
06:20	alinpopa	,(.size '(1 2 3))
06:20	clojurebot	3
06:20	alinpopa	,(.length "abc")
06:20	clojurebot	3
06:37	leafw	alinpopa: it's the same really. count will call .length or .size, setup on read time, depending upon data type.
06:37	alinpopa	leafw: thanks for explanation
06:38	alinpopa	I noticed that count is more general form (eg. instead of using .length for String and .size for collections, count can be used for both)
06:54	tomsw	ok, I'm used to CL. Here's my attempt to shuffle a collection...
06:54	lisppaste8	tomsw pasted "Shuffle a collection" at http://paste.lisp.org/display/75328
06:54	tomsw	Comments welcome: be cruel to be kind (but not too cruel...)
06:59	Chousuke	tomsw: why the weird destructuring?
07:00	Chousuke	tomsw: looks like you should instead just overload it for one and two arguments
07:01	tomsw	Chousuke: the optional "up-to"?
07:03	lisppaste8	Chousuke annotated #75328 with "overloaded... not guaranteed to have matching parens." at http://paste.lisp.org/display/75328#1
07:03	Chousuke	gah! just a moment after I clicked submit I noticed one missing paren...
07:03	Chousuke	after the (shuffle coll (count coll))
07:05	tomsw	Chousuke: oh I get it. I didn't want to duplicate code, forgot that one overloading can use another.
07:05	Chousuke	otherwise that looks okay I think.
07:06	Chousuke	I think there's an implementation in contrib that copies the coll into a java array and uses java's shuffle, then returns that in a vector
07:06	tomsw	Chousuke: that's just cheating
07:06	Chousuke	yeah, it is :)
07:07	Chousuke	but sort does it too
07:07	Chousuke	it's probably a fair bit faster for larger collections too :/
07:07	tomsw	Chousuke: also, the wheel isn't as new & shiny as it used to be
07:07	ayrnieu	cheating is destructively sorting a linked list via an array of pointers to cons cells.
07:08	ayrnieu	going through a java array is just good sense :-)
07:08	Chousuke	I guess the immutable data structures just aren't fit for shuffling very efficiently :)
07:08	Chousuke	not that it matters much
07:10	tomsw	Chousuke: I have been trying to work through "Purely functional data structures" which shows how you can get good performace with immutable data structures. Just haven't got far enough to spot anything that might apply to shuffling. Quite a good way to hurt your brain though
07:11	Chousuke	well, shuffling is something where it's beneficial to be destructive, at least during shuffling
07:11	Chousuke	since you don't care at all about what the structure looks while you're shuffling
07:14	Chousuke	if you do the copy-and-shuffle trick the function remains purely functional to the outside anyway (to the extent that functions producing random results can be called purely functional)
07:15	tomsw	Chousuke: :) not at all, in fact...
07:19	Holcxjo	But, if you do it purely functional you might be able to do parallelise the shuffling?
07:19	ayrnieu	Chousuke - they can't. But you can pass them the RNG's state, or imply this in a state-of-the-universe argument.
07:20	ayrnieu	but they can be pure and nondeterministic.
07:34	tomsw	is there a good way to look up the java docs from inside Emacs?
07:37	Holcxjo	tomsw: (use ['clojure.contrib.javadoc])
07:37	Chousuke	Holcxjo: that's easy to do with copying and destructive shuffling as well: just shuffle each half separately and concatenate :)
07:37	Holcxjo	That's the best I know
07:37	Holcxjo	then (javadoc String) and a browser should open up
07:39	Holcxjo	Chousuke: True :-) Although you might actually get better memory performance if you don't write into an consecutive array from multiple CPUs as the same time.
07:43	tomsw	Chousuke: ? but if you split a sequence in half & shuffle the halves separately, it won't be a fair shuffle
07:43	Holcxjo	tomsw: Nope, you'll need to do more work
07:43	Holcxjo	tomsw: He was just commenting on my paralisability comment
07:45	Holcxjo	tomsw: and the more I think about it, the less I am convinced one can improve it much with parallel processing
07:45	AWizzArd	cool would be if one could simply do (sort random collection) and it shuffles that stuff
07:56	tomsw	AWizzArd: trouble is that most sort algorithms assume they're sorting an ordered datatype - ie, two given items always have the same order. This won't be the case if your sort predicate is non-deterministic - and the combination won't guarantee a fair shuffle
07:58	achim_p	in some situations you could assign random values beforehand
07:58	achim_p	,(map val (sort-by key (zipmap (repeatedly rand) (range 10) )))
07:58	clojurebot	(4 7 9 8 3 5 1 6 0 2)
07:58	Holcxjo	shuffle is only O(n) right? Relying on sort (assuming it works as intended) is likely to get you into the O(n log n) teritory.
07:58	achim_p	Holcxjo: right
07:59	Holcxjo	Sounds like a silly tradeoff
07:59	achim_p	but tomsw's shuffle looks quadratic as well
07:59	achim_p	remove-at is linear, i think
08:00	Holcxjo	Oh, yes that might be.
08:01	Holcxjo	One should probably use vectors and swap elements -- that's meant to be (amortised) O(1), right?
08:02	tomsw	so copy the sequence into a vector, swap, copy it out again
08:02	AWizzArd	if the shuffeling is not a task which the computer needs to do for hours and hours, then the efficiency may not matter very much.
08:03	cemerick	Chouser: you did up a 2x2 of the various reference types (atoms, refs, vars, etc) -- where might that be?
08:03	Chouser	cemerick: http://clojure.googlegroups.com/web/clojure-conc.png
08:04	Chouser	that's missing var and now future
08:05	cemerick	or, :-(
08:06	rhickey	Chouser: while future and delay now both support deref, I don't consider them full references as they don't mutate
08:06	Holcxjo	More reliable than sort and still in the silly teritory would be to use be to use clojure.contrib.combinatorics's (permutations coll) -- pick a random numbe between 0 and (factorial (count coll)) and use that as an index into the collection of permutations...
08:07	Holcxjo	Put I guess, contrib.lazy-seqs's random-permutation is the real answer...
08:07	cemerick	rhickey: thanks again for your rapid assistance a few days ago. Our entire codebase is now safely "ported" to HEAD.
08:07	rhickey	cemerick: that's great!
08:07	Holcxjo	(which "cheats" and used java.util.Collections/shuffle )
08:08	AWizzArd	Is using random-permutation then also cheating? ;)
08:10	Chouser	future .isDone mutates, but I guess that's not quite the same thing.
08:11	applicable	can someone writ the ycombinator in clojure?
08:12	rhickey	Chouser: isDone is not the cell itself
08:12	Chouser	applicable: like this? http://groups.google.com/group/clojure/browse_frm/thread/3259f09e08be4cfd/21f0e19fdce15ae9
08:13	rhickey	I'm running our of words to distinguish the indirection part from the mutable box part
08:14	Chouser	"isDone is not the reference"?
08:14	Chouser	eh.
08:18	lisppaste8	AWizzArd pasted "Kent Pitmans implementation of the Y-Combinator, for applicable" at http://paste.lisp.org/display/75330
08:20	AWizzArd	rhickey: maybe short fantasy names can be used? (fub ...) (shunk ...) and so on?
08:20	AWizzArd	"Let's shunk-fub this code..."
08:23	Holcxjo	When running out of names, using a different language is always a good choice. Classic Sanskrit is good as there won't be any name clashes with existing code...
08:24	Holcxjo	.. readablity suffers a bit though.
08:26	leafw	switch to spanish -- second world language.
08:26	leafw	I meant, second language in the world.
08:26	Holcxjo	Right after Chinese?
08:27	leafw	yes.
08:27	Holcxjo	so, why not Chinese?
08:27	leafw	latin script.
08:28	leafw	not symbols.
08:30	Holcxjo	Ah yes, Java is still stuck in the 20th century and doesn't cope with Unicode identifiers, right?
08:31	Chouser	no, Clojure can handle unicode identifiers, but they're generally avoided by builtins.
08:32	cemerick	if you're on a mac, a lot of useful mathematical symbols are an easy shortcut away, which helps a lot
08:37	Chousuke	heh
08:37	Chousuke	no lambda shortcut on this layout though ;(
08:38	Chousuke	wonder if clojurebot allows defmacros now.
08:38	Chousuke	,(defmacro ? [& body] `(fn ~@body))
08:38	clojurebot	DENIED
08:38	Chousuke	:(
08:39	cemerick	Chouser: fwiw, it's easy to remap some keybinding to lambda on the mac using DefaultKeyBinding.dict (a simple plist mapping between keystrokes and what you'd like them to emit)
08:39	Chousuke	well, yeah
08:40	AWizzArd	cemerick: even easier when you use the Neo layout instead of qwertz. There you have several greek letters available. "lambda" could be written as "??????" for example :)
08:41	cemerick	Chousuke: nope, I'm a simpleton :-)
08:44	Chousuke	When doing tabcompletion, irssi prefers people who were last seen speaking
08:44	Chousuke	one of those features you wouldn't think of at first, but make a whole lot of sense when you think about it.
08:49	leafw	Chousuke: irssi has a large club of fans.
08:49	leafw	Chousuke: irssi has a large club of fans.
08:49	leafw	detachable IRC non-browser bound. Like, reinventing water (and awesome)
09:11	lisppaste8	tomsw annotated #75328 with "untitled" at http://paste.lisp.org/display/75328#2
09:15	rsynnott	Chousuke: that feature can occasionally be terribly confusing
09:36	AWizzArd	,(doc call-future)
09:36	clojurebot	java.lang.Exception: Unable to resolve var: call-future in this context
09:36	Chousuke	,(doc future-call)
09:36	clojurebot	"([f]); Takes a function of no args and yields a future object that will invoke the function in another thread, and will cache the result and return it on all subsequent calls to deref/@. If the computation has not yet finished, calls to deref/@ will block."
09:37	AWizzArd	Can one (await a-future)?
09:38	Chousuke	await is for agents
09:38	Chousuke	all you need to do is @afuture
09:39	AWizzArd	future-call will directly fire off the execution? Or will that future only run when I try to deref it?
09:40	Chousuke	AWizzArd: it'll start instantly.
09:41	Chousuke	it's a computation that will complete sometime in the future.
09:42	Chousuke	so you can start the computation, do other stuff and use the future result when you need it; if it isn't completed yet, it'll just block until it's done.
09:42	Chousuke	"easy" threading :)
09:42	AWizzArd	yes
10:31	Chouser	this stupid graph has me peeved. why can't I find better tools for this?
10:42	cemerick	Chouser: graph of?
10:45	Chouser	the class inheritence
10:45	Chouser	it's just a directed graph, with the connections created programmatically.
10:45	cemerick	ah, yeah, stuff like that can be very painful
10:45	AWizzArd	strange that there are no Java tools yet, to visualize that
10:45	Chouser	graphviz dot is a fine 80% solution (or maybe 60%)
10:46	cemerick	of course, the real goods are in the last 5%
10:46	cemerick	AWizzArd: there's lots of options, but none ever really do all that you want
10:46	Chouser	but the latest inheritence change (adding Counted) has pushed it over the edge, and the thing is now unreadable, and I'm simply failing to find a way to fix it.
10:47	cemerick	Chouser: do you have a draft of the new version? Maybe it's not really that bad...
10:47	Chouser	I think what I want is dot (or something like it) to produce an initial layout, and then be able to drag around nodes or groups of nodes manually
10:47	Chouser	cemerick: http://chouser.n01se.net/misc/tmp.png
10:48	Chouser	cemerick: if you can tell by looking at that chart what two things IPersistentSet implements, I'll publish this version.
10:49	Chouser	anyway, that doesn't sound like a tall order, but apparently it is. :-P
10:50	cemerick	IPersistentCollection and Counted, I think :-D
10:50	Chouser	heh. yeah. very nice.
10:50	Chousuke	cemerick: you're good at guessing
10:50	cemerick	honestly, I've seen much worse
10:50	Chouser	but it needs to me useful, otherwise what's the point?
10:51	cemerick	Chousuke: :-) well, there are only so many pink lines, and the only other options was PersistentQueue, but that didn't have an arrow
10:51	Chouser	,(parents clojure.lang.IPersistentSet)
10:51	clojurebot	#{clojure.lang.IPersistentCollection}
10:51	cemerick	don't know what to say to color-blind people, though
10:51	Chousuke	maybe it'd be better to have some kind of "badges" for the most common interfaes
10:52	Chousuke	and just tag other interfaces and classes with those badges.
10:52	Chouser	oo!
10:52	cemerick	Chouser: omnigraffle has really good tools for rearranging graphs "gently" -- so you could move stuff around as you like, and it tries to satisfy whatever other constraints you've set while disturbing your manual placements minimally
10:53	cemerick	not sure what it has under its sleeve for data import, tho
10:53	Chouser	cemerick: yeah, that's usually the kicker.
10:53	Chouser	there are the nice interactive tools, and then there are the ones with clean data import
10:54	Chouser	I've been eyeing the idea of using xslt to tweak an inkscape svg file, but ... well... sigh
10:54	cemerick	Chouser: omnigraffle pro supports graphviz dot files, apparently: http://paco.to/blog/000040.html
10:55	cemerick	I have OP, if you want me to give it a shot with the dot file you have
10:55	lisppaste8	Chouser pasted "latest graph.dot for cemerick" at http://paste.lisp.org/display/75338
11:04	Chouser	it looks like they're working on something called smyrna that may do what I want.
11:18	AWizzArd	rhickey: is there a plan for a lazy version of futures? One which only kicks of the execution of the future when the deref is made?
11:19	jbondeson	AWizzArd: but then it would immediately block your thread of execution
11:20	AWizzArd	why?
11:20	jbondeson	deref'ing a future blocks until the calculation is complete
11:20	AWizzArd	right
11:20	AWizzArd	it would only block when the deref happens
11:20	jbondeson	so if it waited until a deref request you'd be blocked.
11:21	AWizzArd	but if it never happens then my other threads get more cpu time.
11:21	jbondeson	so it would act exactly like a lazy function evaluation.
11:21	AWizzArd	yes
11:21	AWizzArd	,(doc delay)
11:21	clojurebot	"([& body]); Takes a body of expressions and yields a Delay object that will invoke the body only the first time it is forced (with force), and will cache the result and return it on all subsequent force calls"
11:22	jbondeson	i'm confused why you would use futures for that.
11:22	jbondeson	seems like you want a new object that implements deref that evaluates the function when you deref
11:23	Chousuke	that's delay :/
11:23	jbondeson	kinda, it's a thin wrapper over delay that makes it look like a regular reference
11:23	Chousuke	,(let [a (delay (println "test") 1)] (println "test2") @a)
11:23	clojurebot	1
11:24	clojurebot	test2 test
11:24	jbondeson	oh hey look at that
11:24	Chousuke	the funky print order is due to how clojurebot handles out
11:24	jbondeson	sooo, now i'm really confused why delay doesn't work for you AWizzArd
11:25	AWizzArd	jbondeson: before I write 3 minutes ago ,(doc delay) I did not know about the existance of delay.
11:25	cemerick	Chouser: so, OP will create a decent force-directed graph, but that loses all of the nice alignment of related items
11:26	AWizzArd	wrote
11:26	jbondeson	ah
11:27	Chousuke	hm
11:27	Chousuke	it's not like the lines in the graph need to be continuous, as longs as it's clear where they connect :)
11:28	Chousuke	-s
11:28	Chousuke	I have no idea how to do that with dot though :/
11:29	cemerick	I can post what OP produced, but I don't think it's an improvement...
11:30	Chouser	well, I posted this yesterday too, but it wasn't popular: http://chouser.n01se.net/misc/tmp2.png
11:30	danlarkin	hurts my eyes!
11:30	Chouser	but you can tell where the lines are going, and you can read the text.
11:31	Chouser	all its missing is a certain aesthetic
11:31	Chousuke	I mean, why do you need lines at all
11:31	AWizzArd	jbondeson: is it new that you can (deref a-delay)?
11:32	Chousuke	I think UML has some notation for a "teleport" kind of thing :P
11:32	AWizzArd	I can not run your example, I have to use (force a)
11:32	Chousuke	AWizzArd: I think it was added with futures.
11:33	jbondeson	AWizzArd: with futures IDeref was added, so yeah, i think that's where it came in
11:34	jbondeson	i didn't even know you could do that, but you learn something new every day.
11:35	gnuvince	Is there an easy way to get the entire content of a file in a string with Clojure? (something (reader "/etc/passwd"))?
11:36	Chouser	slurp
11:36	jbondeson	love that name
11:36	Chouser	I must say I prefer slurp to spit
11:36	jwinter	,(doc slurp)
11:36	clojurebot	"([f]); Reads the file named by f into a string and returns it."
11:36	rhickey	Chouser: spew?
11:36	gnuvince	Chouser: thanks
11:36	leafw	I find line-seq easier to use than slurp -- or rather, more useful.
11:37	gnuvince	Always forget about it
11:37	Chouser	hurl? expectorate? regurgitate?
11:37	Chouser	write?
11:37	jwinter	leafw: how do you use line-seq?
11:40	cooldude127	does clojure have a way to extend the reader?
11:40	leafw	jwinter: http://github.com/acardona/xmms2-clj/blob/89ae9d125af9968fefcf7c31505c23000a29c0f4/xmms2.clj#L34
11:41	leafw	jwinter: just give a reader to line-seq.
11:41	jwinter	leafw: cool, thx
11:41	Chouser	cooldude127: like adding new reader macros? no.
11:42	cooldude127	Chouser: :( is it planned at some point?
11:43	Chouser	cooldude127: if you can figure out how to allow reader macros from different authors to be used at the same time, perhaps.
11:43	Chouser	in other words, no.
11:43	shoover	cooldude127: regarding your complaint yesterday about Math functions, have you seen clojure.contrib.import-static?
11:44	fanda	Chouser: concerning creating graph of Clojure classes/interfaces...
11:44	fanda	one time I used yEd Graph Editor:
11:44	fanda	http://www.yworks.com/en/products_yed_about.html
11:44	fanda	all you need is to generate for example .gml file, import it and then use some layout from the menu
11:44	fanda	i guess it is more manual than graphviz, but it gives you more power...
11:45	AWizzArd	leafw: why not read-lines?
11:45	AWizzArd	in duck-streams
11:45	cooldude127	shoover: no, but really i'm disappointed in clojure's not having it's own math functions, for instance ones that work on ratios too
11:45	cooldude127	like absolute value
11:46	cooldude127	and such
11:46	rsynnott	danlarkin: I'm very used to languages which haven't really changed in the last decade :)
11:46	jbondeson	the only thing you have to be careful about with read-lines is that if you don't consume the entire sequence the file doesn't close
11:47	Chouser	fanda: thanks for yED -- I'll look at it.
11:49	rsynnott	cooldude127: you could always write your own
11:50	p_l	danlarkin: The problem with changing languages is that sometimes you find this very useful piece of code, only to end with it not compiling because while it looks completely okay, someone changed the language since that time... <--- happened few times to me
11:51	danlarkin	p_l: yup, that'll happen
11:51	danlarkin	c'et la vie!
11:52	p_l	danlarkin: When 'if(!var)' stops working, people get angry :-)
11:52	jbondeson	you only really have to worry about that if you're providing other people with code, because you could always include a specific version of clojure in your jar you distribute.
11:52	Chousuke	At least Clojure still has a good excuse to change. :)
11:52	rsynnott	indeed
11:52	rsynnott	oh, I'm not complaining about it
11:53	rsynnott	it's just not at all what I'm used to
11:53	Holcxjo	Chouser: I had some luck with "mclimit=2500.0" in my .dot files -- improved the layout somewhat
11:53	cooldude127	rsynnott: i did, i was just disappointed that i had to
11:53	leafw	AWizzArd: didn't know about read-lines. But line-seq is lazy -- that alone is nice.
11:53	p_l	Also, I guess that with clojure one could use macros to provide "compatibility layer" :-)
11:54	jbondeson	leafw: read-lines is lazy too.
11:56	rsynnott	p_l: to run programs for revision X on revision Y, use THIS macro, for revison Z use THAT macro :)
11:56	rsynnott	could get messy
11:57	leafw	,(doc read-lines)
11:57	clojurebot	java.lang.Exception: Unable to resolve var: read-lines in this context
11:57	leafw	aha. So read-lines is not in std clojure lib
11:57	leafw	didn't know why I hadn't come across it.
11:57	jbondeson	clojure.contrib.duck-streams
11:57	leafw	,(doc line-seq)
11:57	clojurebot	"([rdr]); Returns the lines of text from rdr as a lazy sequence of strings. rdr must implement java.io.BufferedReader."
11:58	jbondeson	you are responsible for teh reader you provide, read-lines will open the file for you and close it after you consume the sequence.
11:58	p_l	rsynnott: I envisioned something more like loading a jar which would use macros to redefine few things to emulate behaviour from a certain "version" (more like snapshot of language :) )
12:01	p_l	afk
12:01	Chousuke	jbondeson: what if you never consume it fully, though? :/
12:03	jbondeson	Chousuke: then it's not closed until the seq gets GCed.
12:03	jbondeson	if you're going to read the whole file it's good.
12:03	jbondeson	if you're not... well, i suppose you want something else.
12:06	jbondeson	it's just really handy when you know you're going to consume the entire file to not have to worry about the file reader object
12:09	technomancy	can someone explain to me why I can't call "read" on something I got from the "reader" function in duck-streams?
12:09	technomancy	seems like if I have a reader, I should be able to read, no?
12:09	technomancy	otherwise why call it a reader?
12:11	Chouser	'read' needs a particular kind of reader, but it's name is based on lisp history.
12:11	cooldude127	read is the R in REPL
12:11	cooldude127	:)
12:12	technomancy	Chouser: couldn't it be made smart enough to turn a regular reader into a pushback reader?
12:15	technomancy	a pushbackreader just means that characters can get pushed back onto the stream?
12:15	Chouser	I think so
12:17	technomancy	it's a nit-picky thing, but it really bugs me to have to say (read (java.io.PushbackReader. (reader file)))
12:18	technomancy	I suspect the problem with that is you'd have to turn read into a multimethod?
12:20	cooldude127	technomancy: you wouldn't have to, but it would be more elegant
12:20	cooldude127	wait is read implemented in clojure?
12:21	cooldude127	how could it be? you need a reader before you can do clojure
12:21	technomancy	cooldude127: it calls clojure.lang.LispReader
12:21	cooldude127	oh
12:22	technomancy	which I guess you could add a read method to that could perform the conversion?
12:22	technomancy	and you wouldn't have to change any existing code
12:23	rsynnott	how are multimethods implemented for JVM, actually?
12:24	Chouser	rsynnott: clojure multimethods?
12:27	technomancy	I'll bring it up on the mailing list
12:43	scottj_	What's the idiomatic way to do cl's loop collecting?
12:45	rsynnott	Chouser: yep
12:45	Chouser	you need to build a new collection from an old one? only including non-nil things? (sorry don't know C:)
12:46	ayrnieu	scottj - for, filter, a function with a recursive (loop [accumulutor] ...)
12:46	rsynnott	I had the idea, though I may be wrong, that ABCL's poor CLOS performance was due to some problem in implementing clos multimethods in hava
12:46	technomancy	is there a slight performance hit when invoking multimethods vs regular functions?
12:46	Chouser	rsynnott: each defmethod is an object that has a map of dispatch values to fns
12:46	Chouser	technomancy: yes
12:47	rsynnott	ah
12:48	Chouser	rsynnott: the multifn also keeps a cache mapping the dispatch fn's return value to the appropriate defmethod fn.
12:48	Chouser	sorry, messed up the earlier statement. each defmulti is an object...
12:49	ayrnieu	rsynnott - it may just be a bad implementation. But there's some activity just last month, with someone getting Closette on ABCL http://article.gmane.org/gmane.editors.j.devel/2276 , and with this thread http://article.gmane.org/gmane.editors.j.devel/2258
12:50	Chouser	so the given dispatch fn is called for every call to the method, but the heirarchy computation is cached so will be just an extra map lookup
12:50	Chouser	and I imagine all that gets in the way of hotspot efficiently inlining it, but I don't know that for sure.
12:51	rsynnott	ah, it has a MOP; cool
12:51	Chouser	http://code.google.com/p/clojure/source/browse/trunk/src/jvm/clojure/lang/MultiFn.java
12:52	rsynnott	what's going on with the invokes, there?
12:52	rsynnott	is it an optimisation, or does java lack functions with arbitrary numbers of parameters?
12:53	rsynnott	oh, nevermind, found it :)
12:55	Chouser	well, I think Chousuke idea of badges was fantastic. So is this implementation decent? http://chouser.n01se.net/misc/tmp3.png
12:56	jbondeson	nice
12:56	gnuvince	Chouser: what's the lib to generate this?
12:57	Chouser	gnuvince: /tree/master
12:57	Chouser	um
12:57	Chouser	gnuvince: http://github.com/Chouser/clojure-classes
12:57	jbondeson	I take it Clojure Interface/Class vs. Java Interface/Class is anything in clojure.* and anything not?
12:57	Chouser	jbondeson: right
12:59	Chouser	This doesn't include any of the nested classes.
12:59	Chouser	there are many more ISeq types
13:04	jbondeson	aww, you hardcoded some of the mappings ;)
13:05	Chouser	colors, predicates, and one alias
13:05	Chouser	and badges, now
13:10	lisppaste8	gnuvince pasted "Any way to prettify this?" at http://paste.lisp.org/display/75347
13:13	craigmcd	Anyone have a working example of :exposes-methods from gen-class?
13:16	Chouser	gnuvince: I don't think there's any point in avoiding 'count', is there?
13:16	Chouser	(defn avg [coll] (/ (reduce + coll) (count coll)))
13:17	ayrnieu	(defn avg [coll] (/ (reduce + coll) (count coll))) ... too slow.
13:17	Chouser	:-)
13:17	brianh	man, just looked at that MultiFn java code. rhickey must've felt like a pirate after typing all of those args....;)
13:17	Chouser	brianh: ha!
13:17	technomancy	hehe
13:18	gnuvince	Oh right, count is O(1) for most data structures now
13:19	rhickey	that brings up a poll I wanted to do - what's the max number of fixed args you have in your Clojure code?
13:19	rhickey	gnuvince: that O(1) count is not new, I've strived for it everywhere possible
13:20	ayrnieu	I see a (defn bifold [p f1 f2 acc1 acc2 coll] , but the average is probably 1 or 2.
13:20	gnuvince	rhickey: ah, I didn't know that.
13:20	danlarkin	rhickey: 8
13:21	gnuvince	4 args max here.
13:21	technomancy	bonus points if you write a function to look through your codebase to determine the max arg count. =)
13:21	gnuvince	Maybe it should be mentioned here (http://clojure.org/api#count) that count is O(1).
13:22	rhickey	gnuvince: it's not universally
13:22	Chouser	gnuvince: only classes marked with a 1 here can count in O(1): http://chouser.n01se.net/misc/tmp3.png
13:23	rhickey	gnuvince: the new counted? pred will tell you
13:27	mattrepl	craigmcd: http://gist.github.com/62795
13:27	craigmcd	mattrepl: thanks
13:29	craigmcd	mattrepl: I see what I was doing wrong now: (.superUpdate this ...), not (superUpdate ...).
13:29	StartsWithK	lisppaste8: help
13:29	lisppaste8	To use the lisppaste bot, visit http://paste.lisp.org/new/clojure and enter your paste.
13:29	gnuvince	So any class that implements Counted must provide constant time count?
13:30	mattrepl	is that a hint? ;)
13:30	rhickey	gnuvince: yes
13:30	cooldude127	if a namespace is defined, is (ns blah) the same as (in-ns 'blah) ?
13:31	lisppaste8	StartsWithK pasted "Clojure Ant Task (like javac)" at http://paste.lisp.org/display/75350
13:32	StartsWithK	you can use it like <clojurec srcdir='..' destdir='...'/>, it will find all .clj files and compile the, also if there is a error this one stops ant
13:33	technomancy	what's more amazing is that it's actually working on the first try
13:33	gnuvince	technomancy: you're not the only one
13:33	Chouser	cooldude127: no
13:33	cooldude127	Chouser: what's the difference?
13:33	cooldude127	Chouser: it doesn't look like it affects my :use's and stuff
13:34	Chouser	ns always 'refer's clojure.core, unless you modify via :refer-clojure
13:34	lisppaste8	tomsw pasted "Why doesn't the map work?" at http://paste.lisp.org/display/75351
13:34	tomsw	why isn't map doing anything when used inside a awt.Canvas' paint method?
13:35	Chouser	tomsw: map is lazy
13:35	tomsw	Chouser: is there an unlazy version?
13:35	tomsw	Chouser: or must I use take or something?
13:36	Chouser	tomsw: you can wrap it in 'dorun', but you might find 'dotimes' or 'doseq' to be a better fit in this case.
13:36	cooldude127	Chouser: so if i don't care about what it does with :refer-clojure, they're essentially the same
13:36	Chouser	cooldude127: yes, but the namespace existing doesn't change anything
13:37	tomsw	Chouser: Think I better go and so some more reading. Thanks!
13:37	cooldude127	Chouser: wait so does (in-ns) create a namespace too?
13:38	cooldude127	if it doesn't exist?
13:38	Chouser	tomsw: looking at your code a bit more closely, wrapping dorun around your map may actually be the most convenient.
13:38	Chouser	cooldude127: correct
13:39	cooldude127	Chouser: ok, got it. i'm using in-ns anyway, i thought that slime wasn't figuring that out right, but it is, so that's fine
13:39	Chouser	tomsw: or maybe (doseq [[img x y] (map vector imgs (range...) (range...))] (.drawImage ...))
13:42	Chouser	rhickey: thanks for making small literal maps array-maps. that's pleasant.
13:44	rhickey	Chouser: you're welcome, ye, much better now that it's consistent
13:44	rhickey	yes
13:49	alinpopa	good evening
13:49	alinpopa	have one fast q
13:50	alinpopa	time macro, is returning 10.492 msecs for instance
13:50	alinpopa	what this it means ?
13:50	alinpopa	10 milliseconds ?
13:50	ayrnieu	yes.
13:50	alinpopa	ok, thank you
13:51	alinpopa	the doc doesn't tell what is the unit returned
13:51	alinpopa	Macro
13:51	alinpopa	Evaluates expr and prints the time it took. Returns the value of
13:51	alinpopa	expr.
13:51	alinpopa	,(doc time)
13:51	clojurebot	"([expr]); Evaluates expr and prints the time it took. Returns the value of expr."
13:52	alinpopa	492 are ... microseconds ?
13:52	danlarkin	alinpopa: msecs is the unit :)
13:52	rsynnott	alinpopa: yep
13:52	alinpopa	yes danlarkin I noticed :D
13:52	alinpopa	seems to be too fast to be 10 mseconds that's why I asked
13:53	alinpopa	,(time (count (list 1 2 3 4 5 6 7 8 9 10)))
13:53	clojurebot	10
13:53	clojurebot	"Elapsed time: 0.165 msecs"
13:53	alinpopa	I got: "Elapsed time: 0.075 msecs"
13:53	alinpopa	so ... this seems it took how much ?
13:53	alinpopa	75 microsecs ?
13:54	ayrnieu	milliseconds.
13:54	ayrnieu	You just asked, and I answered.
13:54	ayrnieu	And then you thanked me.
13:54	alinpopa	:) yes, I did that
13:55	alinpopa	0.075 msecs = ? msecs ? microsecs ?
13:55	alinpopa	do you see my point now ?
13:56	alinpopa	nevermind, I got the idea
13:58	rsynnott	0.075 milliseconds is 75 microseconds
13:59	lisppaste8	ayrnieu pasted "src/clj/clojure/core.clj:time" at http://paste.lisp.org/display/75353
13:59	tomsw	Chouser: just figured out if I have nested maps I need nested doruns...
13:59	ayrnieu	it seems like that ought to (doall ~expr)
14:00	technomancy	yay, first clojure patch submitted.
14:01	ayrnieu	... to src/clj/clojure/core.clj:time ? That was fast!
14:01	technomancy	heh; no.
14:01	technomancy	to clojure.lang.LispReader
14:01	cooldude127	technomancy: what was your patch?
14:02	technomancy	cooldude127: http://code.google.com/p/clojure/issues/detail?id=79&colspec=ID%20Type%20Status%20Priority%20Reporter%20Owner%20Summary
14:02	technomancy	you can call read on any reader now, not just a PushbackReader
14:02	cooldude127	nice
14:05	cooldude127	synergy as in the kvm type thing?
14:05	te	synergy owns.
14:05	te	truly.
14:05	technomancy	cooldude127: yeah
14:05	cooldude127	fun
14:05	technomancy	I like it, but every now and then it turns my X server into "control is always on" mode
14:06	te	I wish synergy was easier to set up in impromptu situations
14:06	te	like if im in the library it would be nice to hit a button and have both screens
14:06	technomancy	te: mango lassi supposedly does that with zeroconf
14:07	technomancy	but I haven't heard anything about that in a long time
14:07	cooldude127	ok i have some problems getting a (load) statement in my code to work
14:07	cooldude127	i'm splitting a namespace up into a couple files, so i'm using load kinda like the clojure.core code uses
14:07	cooldude127	but it can't find the file
14:08	p_l	te: Have you looked at Plan B operating system? :-)
14:08	cooldude127	ok something's wrong with my classpath
14:09	cooldude127	technomancy: do you know how i can add to the classpath while still using clojure-slime-config?
14:09	Raynes	Good day.
14:09	Raynes	o.o
14:09	cooldude127	i tried a simple add-to-list, and it's not working. slime still loads with the original classpath
14:10	technomancy	cooldude127: add-to-list on swank-clojure-extra-classpaths?
14:10	technomancy	did you kill your inferior-lisp buffer?
14:10	cooldude127	technomancy: yeah
14:10	cooldude127	yeah
14:11	technomancy	cooldude127: hrm; I'm not sure. you could use add-classpath, but that will get you in trouble
14:11	cooldude127	technomancy: i don't want to do that
14:12	cooldude127	there is no reason i shouldn't be able to configure this. let me restart emacs real quick
14:12	cooldude127	technomancy: ok restarting emacs made it change
14:12	cooldude127	the hell if i know why
14:13	p_l	technomancy: What problems are there with add-classpath?
14:13	technomancy	cooldude127: I haven't looked at swank's internals; it could be caching something
14:13	cooldude127	technomancy: it might be
14:13	cooldude127	technomancy: btw, is there any reason that clojure doesn
14:14	cooldude127	't get any pretty lambda/fn love?
14:14	cooldude127	god i hate that ' and RET are right next to each other
14:14	technomancy	p_l: apparently the JVM's classloader makes assumptions about having the full classpath upfront; it's very difficult and unreliable to work around that.
14:14	te	p_l: no I havent' looked at plan b
14:14	te	what is it?
14:14	technomancy	p_l: theoretically that shouldn't affect using add-classpath on clojure code, but people in here will still yell at you for it. =)
14:15	technomancy	cooldude127: mostly because fn is already so short. =)
14:15	technomancy	it would be easy to add though
14:15	te	p_l: this looks like Plan 9
14:15	te	mixed with Inferno-os
14:15	technomancy	te: plan b is plan 9 + 2
14:15	cooldude127	technomancy: i might just do that. the question is do i want the pretty f from the javascript stuff or a lambda
14:16	technomancy	cooldude127: yes. unicode does raise some difficult questions.
14:16	technomancy	I'm confident you'll make the right choice.
14:16	p_l	te: It's Plan 9 with some apps to automate various things... Like entering a room and getting additional displays, room's sound system etc. as devices of your laptop :P
14:16	cooldude127	that's cool as shit!
14:16	cooldude127	technomancy: lol
14:17	te	p_l: dude wtf this is my idea
14:17	te	I really love the idea of physically discrete aspects of my computing environment
14:17	p_l	technomancy: Hmmm. Yell at me you say... Funny that I was just thinking about making something like Haskell's Cabal or RubyGems, which you could use to download/compile/load libraries (and which might need add-classpath)
14:17	te	i find when i have my iphone hooked up to my laptop i am confined to doing just one thing in that space, and i like that
14:18	p_l	te: They're currently working on new, Inferno based system with similar goals
14:18	technomancy	p_l: I think such a thing is an eventual necessity.
14:18	te	i was thinking it might be cool to have 5-10 of those sort of interfaces, small screens, discrete computing environments
14:18	te	tha tbasically provide a ubiquitous interface
14:18	technomancy	p_l: but I'm not convinced there are currently enough libs to justify it.
14:18	te	p_l: i did the google summer of code for inferno-os
14:18	te	it's sad that inferno gets no attention whatsoever
14:18	p_l	technomancy: Java's CLASSPATH is annoying me enough :)
14:18	te	Limbo could have been the next Java
14:19	te	err the /first/ Java
14:19	rsynnott	p_l: java's classpath is very, very annoying
14:19	te	p_l: technomancy: I have class, but I wish I could stay and chat
14:19	technomancy	te: I'll be around. =)
14:20	te	I love this damned channel -- plenty of brave souls who aren't afraid of new ideas
14:20	rsynnott	maven does things with the classpath, so you have to mess around a bit to get it to work properly
14:20	technomancy	p_l: right now the solution to the packaging problem is just "stick everything in contrib!"
14:20	technomancy	which is awesome
14:20	te	so many programmers i meet are of the "oh i dont know about that, isnt that just some new fad language" cloth
14:20	technomancy	but can't last forever
14:20	te	p_l: are you working on plan b at all?
14:20	rsynnott	(I'm writing a comet app in clojure; jetty has decent comet server plugin)
14:21	p_l	te: Not now, but I did setup few Plan9 installs in past, for experiments
14:21	p_l	I'm also lurking on 9fans
14:21	te	Yeah I'm in there as well
14:21	te	some of the guys on that list just dominate
14:21	te	there is such a vast expanse of information and work thats been done its hard to catch up on it
14:22	cooldude127	technomancy: shit i don't think this is good. every defn turned into de?
14:22	te	i had that problem with the google summer of code for inferno
14:22	technomancy	hehe
14:22	te	you basically need to learn the history of computing to code in Limbo
14:22	technomancy	cooldude127: use (fn instead of fn
14:22	rsynnott	it's a shame plan9 didn't work out, really
14:22	p_l	interesting enough, tommorrow is organisational meeting for Computing Society of my Uni. I was wondering of making a set of presentations about various less-known but nice-to-know languages/OSes
14:22	cooldude127	technomancy: lol what if i like this ?
14:22	te	agreed -- although plan9 is kind of a 3rd party candidate, many of its ideas are being filtered intlo Linux
14:22	Chouser	plan9's not open/free, is it? I know it wasn't early on.
14:22	te	It is
14:23	technomancy	cooldude127: I won't question your Alternative Life Choices.
14:23	p_l	Chouser: Now it is
14:23	te	inferno-os was 1million for a license, now its free
14:23	cooldude127	technomancy: i'm gonna fix it, it's too close to a regular def
14:23	te	id like to buy the inferno developer pack from vitanuova
14:23	te	i hear it comes with some cool tools
14:23	Chouser	if it had been free from the beginning, things might be very different now.
14:23	te	Chouser: there's still time
14:23	technomancy	the plan9 stuff that got rolled into wmii was really intriguing
14:24	te	15million lines of code to run Gnome isn't exactly what I'd call efficient
14:24	cooldude127	technomancy: ok i broke it. no more font-lock
14:24	p_l	Chouser: If Research Unix was more widespread, we might never had to work with BSD sockets :D
14:24	te	Plan9 is still the future
14:24	rsynnott	though I don't think many of Bell Labs' research projects have ever turned directly into real products
14:24	te	^^The transistor?
14:24	rsynnott	they pump money into something for a decade or so, then someone else canibalises it, seems to be the way it goes
14:24	te	;)
14:24	te	Bell doesn't really do that kind of research anymore
14:24	te	it used to be /the/ place for cutting edge research
14:24	technomancy	Chouser: you could say that about a lot of things... anything that was a good idea in the 80's basically. =)
14:24	danlarkin	rsynnott: C!?! unix?
14:25	te	now its a relic
14:25	technomancy	CL, smalltalk
14:25	p_l	rsynnott: C, Unix, Plan 9 and Inferno all got commercial use :)
14:25	te	I wrote a distributed synthesizer in Limbo
14:25	technomancy	rsynnott: sounds like Xerox
14:25	rsynnott	te: they still do some interesting work
14:25	cooldude127	technomancy: how can i make this regexp "(?\$fn\\>\$" match (fn instead of fn
14:25	te	i had an orchestra of 386 computers
14:25	te	err 7, 386arch computers
14:26	te	all passing around their data
14:26	Chouser	cooldude127: yikes, is that an emacs regex?
14:26	technomancy	cooldude127: remove the question mark, I guess
14:26	cooldude127	Chouser: yes
14:26	technomancy	Chouser: shield your eyes!
14:26	Chouser	indeed. I think I'll go do something else now...
14:26	rsynnott	I say nearly, because by the time they actually got back to me and offered it to me, I had been working for someone else for a month
14:26	cooldude127	technomancy: perfect
14:26	technomancy	you gotta give them props for making parens literal though; it's great for working with lisp.
14:27	rsynnott	(they're not very efficient. They had to clear all hiring, including internships, in their Dublin facility through their headquarters in New Jersey)
14:28	p_l	rsynnott: management tends to be a PITA...
14:28	rsynnott	then, ridiculously, they got back to me the next year offering me the same position, so I said okay
14:29	rsynnott	and then heard back from them in August, which was three months later than they said, and far too late
14:30	rsynnott	(considering that anyone remotely suitable for their internships will be working during the summer anyway, you have to wonder if they ever manage to fill them at all)
14:40	hiredman	clojurebot: latest?
14:40	clojurebot	latest is 1276
14:40	hiredman	svn rev 1276
14:41	hiredman	clojurebot: well?
14:41	clojurebot	Huh?
14:58	applicable	i want clojure on its own VM or compilable to binaries
14:59	applicable	with its own webserver
14:59	p_l	applicable: GCJ?
14:59	applicable	gcj?
15:00	hiredman	applicable: you don't want the jvm?
15:00	hiredman	is that what you are saying?
15:02	hiredman	clojure is closely tied to the jvm and this integration provides a lot of its greatest strengths, clojure minus the jvm would not be clojure
15:02	p_l	applicable: GCJ is a GNU Java Compiler that can produce native executables (or so I heard)
15:07	p_l	personally, I'd be wary of it
15:07	applicable	canit it have its own vm like python?
15:08	jbondeson	what's the difference between having it's own vm and using the jvm (other than a whole mess more work)
15:08	applicable	isnt there an easy automatic way to compile all the way to a jar?
15:08	jbondeson	you can go directly to a jar
15:08	jbondeson	all you need to use is ant
15:09	applicable	i hate ant, javas tools are all so verbose and donkish
15:09	jbondeson	if you look at the build.xml file with clojure you can easily adapt it to compile your own jar
15:10	p_l	applicable: Isn't that kind of defeating the purpose of removing JVM? There are though slightly different VMs that run/might run Clojure: Dalvik? (Android's VM), IKVM (.NET) etc.
15:11	technomancy	applicable: ant is pretty silly; you could try lancet.
15:11	technomancy	clojurebot: lancet?
15:11	clojurebot	lancet is a build system that works with ant written as an example for the Programming Clojure book.
15:11	jbondeson	lancet is just a clojure layer on top of ant...
15:11	jbondeson	i mean, sure it's less xml-y
15:11	technomancy	yeah, but you don't have to greenspun
15:11	walters	it's not really hard to build jars without ant
15:12	jbondeson	my buil.xml is all of 38 lines...
15:12	walters	jar is just a slight variation of zip, you can run "jar" as a subprocess from make easily enough, pass it the files you want in it, done
15:12	technomancy	jbondeson: every time you write a line of executable XML, a little part of you dies inside.
15:13	jbondeson	technomancy: XML is like violence, if it doesn't work use more.
15:13	jbondeson	;)
15:13	albino	not even a little part, a big huge part
15:13	forest	maven is also very nice tool
15:13	forest	especially for large projects
15:13	jbondeson	i'm sorry, but xml has its uses, and ant's xml is hardly verbose
15:15	jbondeson	heck, i have a build.xml that embeds the contents of other jars into mine and it's still only 58 lines, hardly a problem to write.
15:16	gnuvince	Did something change with regards to type hints recently? My project is suddenly giving me reflection warnings and it running nearly 100x slower than it did two days ago
15:16	hiredman	ouch
15:17	jbondeson	gnuvince: main branch?
15:17	gnuvince	Yes.
15:18	jbondeson	latest rev?
15:18	gnuvince	Yes
15:18	jbondeson	monday the warn option was added...
15:19	jbondeson	do you use pmap heavily?
15:20	gnuvince	Not at all.
15:21	technomancy	jbondeson: wouldn't you rather write Real Code though?
15:21	jbondeson	gnuvince: lots of multimethod calls?
15:21	jbondeson	technomancy: yes, but ant is write once, run foreva'
15:22	jbondeson	technomancy: and lancet is just a thing vaneer over the top of ant, so i'd rather just use ant.
15:22	gnuvince	jbondeson: yes.
15:22	jbondeson	gnuvince: rev 1262 was a patch to the multimethod system
15:23	jbondeson	i would try backing to 1261 and see if that is it.
15:23	jbondeson	if that is a huge speed slowdown it may need a patch
15:23	lisppaste8	gnuvince pasted "New slowness" at http://paste.lisp.org/display/75360
15:26	jbondeson	try 1261 vs 1262 if you could...
15:26	gnuvince	jbondeson: nearly identical
15:27	jbondeson	fast?
15:27	gnuvince	faster
15:27	jbondeson	hmmmm
15:27	jbondeson	so it's not that.
15:27	gnuvince	I'm updating one rev at a time
15:27	gnuvince	up to r1265 now
15:27	jbondeson	only other big one is the Counted changes that Chouser made
15:27	jbondeson	1268
15:28	gnuvince	Still fine at 1268
15:29	gnuvince	Oh wait
15:29	gnuvince	I'm ultra stupid
15:29	gnuvince	duh
15:29	gnuvince	I forgot to run ant
15:29	jbondeson	hahaha
15:29	gnuvince	Let's start this again
15:31	jbondeson	i was wondering how you were pulling-comiling-running those so fast.
15:31	jbondeson	+p
15:31	gnuvince	OK, it's not r1262
15:32	jbondeson	i think 1268 is you next possible suspect
15:33	technomancy	gnuvince: tried git bisect?
15:33	gnuvince	technomancy: svn my friend
15:34	technomancy	gnuvince: you can give git bisect a command to run to validate a revision, and it can automatically binary search to find the commit that caused the breakage. it's badass.
15:34	jbondeson	technomancy: this isn't really a "break" just a slowdown
15:34	jbondeson	though
15:34	technomancy	jbondeson: well, you could return an error code if a certain operation takes too long in your checker script
15:35	jbondeson	true
15:35	technomancy	takes all the guesswork out of finding regressions like this
15:35	technomancy	I get excited every time I use it.
15:36	gnuvince	I wish I could use it
15:36	gnuvince	but I don't think svn ahs this
15:36	technomancy	gnuvince: it works fine with git-svn
15:36	gnuvince	The time it would take to run git-svn, I'll have found the slow revision by then :)
15:37	gnuvince	ding ding ding!
15:37	gnuvince	1268
15:37	technomancy	true
15:37	jbondeson	beat Chouser
15:37	Chouser	:-(
15:37	Chouser	what's the code?
15:37	Chouser	oh, I see it
15:38	gnuvince	Oh wait
15:38	gnuvince	1267 might have the problem too
15:39	jbondeson	1267 was my patch for proxy, unless you're creating a million proxies...
15:39	gnuvince	No proxies in there.
15:40	Chouser	you get extra reflection as of 1268?
15:40	gnuvince	Chouser: earlier than that it seems
15:40	gnuvince	I'm trying to narrow it down
15:40	gnuvince	r1264 is fine; I get the extra warnings starting at r1265
15:41	p_l	hmmm.... is there any elisp code for integrating JDE and Clojure? NetBeans is a little unwieldy in places (read: Java & XMonad don't go well together), but I don't want to lose completion of Java objects...
15:41	jbondeson	that's odd
15:41	gnuvince	,r1265
15:41	clojurebot	java.lang.Exception: Unable to resolve symbol: r1265 in this context
15:41	gnuvince	svn r1265
15:41	gnuvince	clojurebot: svn 1265
15:41	clojurebot	svn is http://clojure.googlecode.com/svn/trunk/
15:41	gnuvince	Not super useful
15:41	hiredman	svn rev 1265
15:41	Chouser	clojurebot: rev 1265
15:41	clojurebot	Titim gan �ir� ort.
15:41	hiredman	sigh
15:42	gnuvince	r1265 \| richhickey \| 2009-02-10 12:24:20 -0500 (Tue, 10 Feb 2009) \| 1 line
15:42	gnuvince	Changed paths: M /trunk/src/clj/clojure/core.clj
15:42	gnuvince	added inlining on remaining coercions
15:42	jbondeson	it's the inlining
15:42	Chouser	gnuvince: oh, this is that tortured bit of coersion we were messing with before, isn'tit.
15:42	jbondeson	do you use boolean, char, byte or short?
15:43	technomancy	p_l: I haven't heard of anyone using tho two together unfortunately
15:43	gnuvince	jbondeson: byte and char
15:43	jbondeson	ah
15:43	gnuvince	jbondeson: I'll give you the link
15:43	gnuvince	http://github.com/gnuvince/clj-starcraft/blob/3d8cd9b36728eb43b32c4c3d5c88d08898e8a916/starcraft/replay/parse.clj#L14
15:43	gnuvince	get-byte and get-short are the ones affected.
15:44	p_l	technomancy: Well, I'll try to set something together. Java's library is a little too big to use without autocomplete (and too verbose)
15:45	gnuvince	Chouser: yes, it is.
15:46	clojurebot	svn rev 1265; added inlining on remaining coercions
15:46	hiredman	clojurebot: fool
15:46	clojurebot	No entiendo
15:46	albino	starcraft replay files, this sounds awesome
15:47	hiredman	weird
15:47	hiredman	I was getting stackoverflow when derefing a ref
15:47	jbondeson	oh
15:47	gnuvince	So... what can I do?
15:47	gnuvince	File a bug report?
15:48	gnuvince	Or is there a new way to use short and byte?
15:48	jbondeson	the RT cast functions are casting from Object -> Number -> Value
15:48	jbondeson	char does an instanceOf
15:48	jbondeson	char is what's killing you.
15:48	Chouser	no, it's the reflection that kills
15:49	p_l	technomancy: Apparently someone managed to make it possible without JDE, writing some clojure code to use Java Reflection API :)
15:49	gnuvince	I'm enclined to agree with Chouser; last time this program was slow, he helped me get the type hints right and it sped the application significantly.
15:49	Chouser	I mean, I'm sure avoiding an instanceOf would help too, but the reflection always hurts more than almost anything else.
15:50	jbondeson	gnuvince: for now you can just do (. x (byteValue))
15:52	jbondeson	Chouser: does casting in Java use reflection?
15:52	gnuvince	jbondeson: same problem, Clojure complains that byteValue cannot be resolved.
15:52	jbondeson	hmmm.
15:53	technomancy	p_l: if I find myself unable to avoid writing Java in the future I may be interested in helping w/ that
15:53	jbondeson	sorry
15:53	Chouser	jbondeson: by reflection I mean what Clojure is warning about. Specifically it's failing, at compile time, to choose exactly one method to call, so it produces code that checks at runtime.
15:54	Chouser	so it's at the clojure/java boundary
15:54	jbondeson	interesting.
15:55	gnuvince	How should I proceed? Write up a summary of the problem, post it on the mailing list and wait until Rich says it's okay to add it to the list of issues on the tracker?
15:55	jbondeson	the weird thing is that the byteCast and shortCast only take objects, and everything should be able to be boxed in Java, correct?
15:57	jbondeson	i come from .net land, so my java knowledge is non-existent.
15:57	Chouser	gnuvince: probably. get-short and get-byte each stand alone to produce the warning. post those with the needed import line, and you should get some response
15:58	gnuvince	Chouser: ok
16:12	Chouser	gnuvince: that's a tough nut to crack.
16:12	Chouser	I can't figure out how to get the byte to hint either as a primitive int or as an Object.
16:13	Chouser	(defn get-byte
16:13	Chouser	[#^ByteBuffer buf]
16:13	Chouser	(let [x (int (.get buf))
16:13	Chouser	y 0xff]
16:13	Chouser	sorry
16:13	Chouser	...except to use (int ...) which itself requires reflecton.
16:15	gnuvince	Chouser: I'm almost done with my post
16:17	gnuvince	http://groups.google.com/group/clojure/browse_frm/thread/53bcf20ff17b73ed#
16:20	Chouser	well, I just found a way to avoid reflection, but it may still be slower than what you had working before.
16:20	gnuvince	I'll report the problem
16:20	gnuvince	I'd rather we have a real solution than a workaround.
16:20	Chouser	yep
16:20	gnuvince	We're not PHP
16:20	Chouser	:-)
16:21	lisppaste8	Chouser pasted "workaround for gnuvince" at http://paste.lisp.org/display/75363
16:22	Chouser	bouncing the byte/short through Box gets you an Object hint, so that the compiler can pick the and(Object,Object) method.
16:22	gnuvince	OK
16:23	jbondeson	seems like creating a function to do the bit-and that takes a Byte also works
16:24	Chouser	ah, disallowing the inline form. that makes sense.
16:25	Chouser	yeah, that's better than mine.
16:26	technomancy	gnuvince: I'm curious: what does replaying a starcraft file look like?
16:26	jbondeson	found one more way
16:26	jbondeson	well, really it's the same way, but without a separate function
16:26	technomancy	gnuvince: I mean, are you visualizing anything, or is it just "this SCV went to this position", "This ultralisk attacked a Marine", etc.
16:27	Chouser	(#'bit-and (.get (ByteBuffer/allocate 100)) 0xff)
16:27	gnuvince	technomancy: It's a big binary string packed in a weird format (for which unpacker libs exist in C and Java, fortunately)
16:27	lisppaste8	jbondeson pasted "workaround 2" at http://paste.lisp.org/display/75364
16:27	gnuvince	technomancy: it's just the commands given by the players. I imagine that given the same input, Starcraft does the same thing (including glitches), so they just need to record what the players did.
16:28	technomancy	gotcha
16:28	gnuvince	technomancy: http://github.com/gnuvince/clj-starcraft/blob/3d8cd9b36728eb43b32c4c3d5c88d08898e8a916/starcraft/replay/actions.clj
16:28	gnuvince	technomancy: these are the known actions
16:29	gnuvince	Isn't it possible simply deactivate the inlining form?
16:29	applicable	if i have a .java file and want to use it form clojure, what do i ahve to do? first compile then make a jar out of it?
16:30	technomancy	applicable: yeah
16:30	Chouser	gnuvince: how? #' does it, but how else?
16:30	technomancy	well, you might not need to make a jar out of it, but it's probably better if you do
16:30	gnuvince	Chouser: just wondering
16:32	lisppaste8	Chouser annotated #75363 with "slightly less ugly workaround" at http://paste.lisp.org/display/75363#1
16:32	Chouser	I would expect that to match the speeds you were getting before.
16:33	Chouser	best would be if there were bit-and methods for byte and short, then you could just hint your constants and you'd get unboxed speed.
16:34	gnuvince	Chouser: yeah, that gives about the same performance as before.
16:35	gnuvince	Well, I need to leave. That math course is not gonna complete itself, unfortunately :(
16:35	gnuvince	Later
16:35	Chouser	ciao
16:40	applicable	can a .zip file be import from clojure? ie is a .zip thr same a s a .jar?
16:42	applicable	hmm i tired rto jar -c org (a dir) and it went nuts and started beeping
16:43	technomancy	sweet, mire made the github highscore list
16:45	jbondeson	ok, that trouble shooting was a lot more fun than my real job. quick someone else have problems
16:47	technomancy	wow... there are only two libraries on the first five pages of github clojure projects that are more than three months old.
16:49	Chouser	jbondeson: I relate.
16:49	WizardofWestmarc	jbondeson: dude, vb6. Of COURSE it's more fun :P
16:50	jbondeson	worse, fixing others build errors
16:50	WizardofWestmarc	ah still dealing with the build retardation? Awesome
16:51	danlarkin	technomancy: what's the github highscore list?
16:52	technomancy	danlarkin: http://github.com/languages/Clojure
16:52	technomancy	"Most Watched This Week"
16:52	danlarkin	sweet
16:53	WizardofWestmarc	Ring hit first in clojure? Huh. Not surprised Programming Clojure's is #2 though
16:55	WizardofWestmarc	...Ring is most forked too? double huh
17:05	applicable	so can a .zip-file be used as a package?
17:05	jwinter	Where are the backtick, ~, and ~@ operators mentioned in the docs?
17:05	applicable	or a .java file can never be accessed form clojure+ it has to be compiled ot .class(i suppose9?
17:05	jwinter	I didn't see them in macros secion.
17:05	ayrnieu	applicable - yes, it has to be compiled.
17:06	Chouser	jwinter: http://clojure.org/reader under Syntax-quote
17:07	jwinter	Chouser: thx
17:11	applicable	me clojure should run on pythons vm instead
17:11	cooldude127	NOOOOO
17:11	applicable	everything java makes me want to kill myself
17:11	p_l	...
17:12	Chouser	applicable: I had similar reactions the first few moneths trying to get comfortable with clojure.
17:12	p_l	applicable: there's little sense in making something target python vm... unless you mean the other Python, which is a compiler :P
17:13	kotarak	And to improve concurrency we get the global lock back.
17:14	danlarkin	long live the GIL
17:14	applicable	long live haskell!
17:19	scottj_	When I get an error in clojure+slime, it appears that the backtrace is pretty much useless because there's so much swank stuff in there I can't actually see my functions. Am I missing something?
17:20	Chousuke	the python VM is not much compared to the JVM though :/
17:20	technomancy	scottj_: the non-slime backtraces are pretty messy too. =\
17:20	technomancy	scottj_: I've been meaning to check out the clj-backtrace library; it's supposed to clean things up
17:24	scottj_	technomancy: do you know if it works with slime or just plain repl?
17:26	Chouser	scottj_: I think there's a keystroke to see the next the deeper 'cause'. are you aware of it?
17:30	scottj_	Chouser: nope
17:31	Chouser	I don't use slime, but my understanding is that some kind of menu pops up and there's an option for the next 'cause'. Often the one you want is the second or last, not the first.
17:31	danlarkin	scottj_: In my configuration (which is whatever aquamacs set up for me) I can press "1" to see the cause
17:31	technomancy	Chouser is right
17:33	clojurebot	svn rev 1277; [lazy] only coerce LazySeq to seq in analyze, fixing evaluation of ()
17:37	scottj_	Chouser: danlarkin, thanks, "1"/cause makes the backtrace a more manageable.
17:37	scottj_	I still long for a clojure debugger that's as easy to understand and use as a smalltalk debugger :)
17:38	technomancy	scottj_: you misspelled Object Browser.
17:38	clojurebot	svn rev 1278; fixed distinct nil handling
17:43	cooldude127	scottj_: i've actually been using smalltalk lately, and that debugger is FANTASTIC
17:43	Chouser	lazy-cons is used quite a lot in contrib.
17:50	Chouser	rhickey: any plans for allowing code to (temporiarily) work with either trunk or lazy?
17:51	rhickey	Chouser: not sure what you mean by that
17:51	Chouser	I'm trying to fix up some things in contrib, but would like to provide two defn for some functions, based on which branch is trying to run it.
17:52	Chouser	(if (resolve 'lazy-cons) (defn foo...) (defn foo...))
17:52	rhickey	Chouser: hmmm... what do you need from lazy/trunk to support that?
17:52	Chouser	but that doesn't work. I'm just wondering if it's something you've thought about.
17:53	Chouser	if you haven't, i'll think about it and get back to you. :-)
17:53	rhickey	ok
17:53	rhickey	the issue doesn't really come up for core
17:54	Chouser	right
17:54	Chouser	but will for any lib, at least for a while.
17:58	Chouser	ok, that was easy. (defmacro only-when [s x] (when (resolve s) x))
17:58	Chouser	(only-when lazy-cons (defn foo ...))
17:58	Chouser	(only-when lazy-seq (defn foo ...))
18:11	Chouser	in trunk, (concat) returns nil, in lazy it returns ()
18:13	rhickey	Chouser: well, that's the key difference between the branches
18:13	rhickey	concat et al no longer return seq/nil
18:15	Chouser	well, that seems to suggest I should feel silly for bringing it up. give me a sec and I probably will...
18:15	rhickey	also note that the () is just a print representation:
18:15	rhickey	user=> (class (concat))
18:15	rhickey	clojure.core$concat__3081$fn__3083
18:15	Chouser	yeah, did exactly that.
18:16	Chouser	it's still not clicking though
18:16	rhickey	that's what I need feedback on - hpw much code depends on sequence fns returning seq/nil
18:18	rhickey	:)
18:20	rhickey	user=> (sequence? (concat))
18:20	rhickey	true
18:20	rhickey	that's the only promise made by the sequence fns
18:22	Chouser	I thought I understood all this, but I'm not yet getting how the code describes that behavior.
18:22	Chouser	gotta go, bbl.
18:53	technomancy	cooldude127: have you thought about a more interesting name for your date library?
18:53	cooldude127	no i have not
18:55	technomancy	how about "chrono"?
19:04	cooldude127	that's a pretty good name
19:07	danlarkin	how about clojure.contrib.date
19:08	technomancy	bland.
19:08	danlarkin	:)
19:08	cooldude127	danlarkin: plus that's what it is right now :)
19:08	danlarkin	oh... well good!
19:08	cooldude127	haha
19:08	technomancy	well... not really; it's not part of contrib yet
19:09	cooldude127	true
19:53	danlarkin	uh oh! circular dependancy... this /is/ annoying
19:55	durka42	circular dependencies are bad...
19:58	danlarkin	represent calls invoke-templattag and invoke-templatetag calls represent :'(
19:59	danlarkin	and that's fine if they live in the same file because I can (declare represent) but it's a problem if I want to separate them
20:01	technomancy	danlarkin: every time I run into that I get annoyed and then start to wonder if I should really be annoyed or if it's just a sign I shouldn't be trying to do that in the first place.
20:02	danlarkin	Hurumph
20:03	technomancy	haven't been convinced either way yet though.
20:03	danlarkin	not sure what I should do differently, they definitely need to call eachother, but they don't really belong in the same file
20:06	durka42	could you trampoline them?
20:06	Chouser	I don't think that would help.
20:07	danlarkin	durka42: already am :)
20:07	cp2	so, i was just given an "emacs vps"
20:07	cp2	see http://www.informatimago.com/linux/emacs-on-user-mode-linux.html
20:08	cp2	quite humorous :)
20:09	technomancy	cp2: I've done the shell version
20:09	cp2	yeah, this is full blown though
20:09	technomancy	once they get webkit embedded, I'll be all over that. =)
20:17	danlarkin	maybe there could be some sort of cross-namespace declare form
20:18	Chouser	do they belong together in a 3rd file?
20:18	Chouser	on the other hand, you're sure you need more than one file?
20:38	danlarkin	Chouser: no, they don't /need/ to be in separate files, but they should be -- they're doing different types of things
20:41	danlarkin	trying to figure out maybe a 3rd file solution
20:46	gnuvince_	Anybody good in calculus?
20:46	gnuvince_	Or just decent will probably do
20:47	cooldude127	gnuvince_: i'm decent :)
20:47	cooldude127	gnuvince_: college student at ga tech here, what you need?
20:49	gnuvince_	cooldude127: moral support mainly
20:49	gnuvince_	And some informations.
20:49	cooldude127	gnuvince_: ok
20:50	gnuvince_	I will preface by saying that I am not good at maths, that I am following a correspondance class (access to the teacher is nigh impossible) and that I am taking the class in French, so I may not know all the terms.
20:50	cooldude127	lol ok
20:50	jbondeson	that's a whole lot of caveats ;)
20:51	gnuvince_	First, here's a very general question: what's the point of a derivative? They suggest in the book that it is used to find the instantenous speed of an object, but why can't we just input the time into the speed function and get the result?
20:51	cooldude127	gnuvince_: what if you don't have a speed function?
20:51	cooldude127	gnuvince_: the derivative will find a speed function
20:51	gnuvince_	cooldude127: In this particular case, I have one; v(t) = -5t^2 + 10t.
20:51	gnuvince_	Why couldn't I just put in the time and get the result?
20:52	cooldude127	gnuvince_: that's exactly what you would do
20:52	p_l	Looks like I'm starting to get some rudimentary library organization for Clojure :)
20:52	cooldude127	unless you're interested in acceleration
20:52	cooldude127	gnuvince_: derivative of v(t) will give you acceleration
20:52	jbondeson	derivatives measure the rate of change of a function.
20:52	cooldude127	exactly
20:53	cooldude127	it will give you the slope of a line that is tangent to a point on a curve
20:53	gnuvince_	The first question with this function is "At the beginning of the experiment, what is the speed of the object?"
20:53	cooldude127	gnuvince_: v(0)
20:53	gnuvince_	I figure 0, but I fear I may be way off track here.
20:54	jbondeson	speed or velocity?
20:54	p_l	gnuvince_: first derivative of a function gives you current "angle". Thus you can use it to analyze whether the function at this point is flat (d(f(x)) = 0), rising, or going down... Second derivative can be used to check for how the slope is shaped (i.e. is the rate of change more and more steep or getting flatter or no change) etc.
20:54	jbondeson	cause tecnically speed is the absolute value of velocity
20:55	danlarkin	oh god! make the calculus go away! I thought I left this in my past
20:55	cooldude127	gnuvince_: with your given velocity function, v(0)=0, so yes 0
20:55	jbondeson	(integrals are easier to hold than derivatives)
20:55	gnuvince_	Oh this is bad...
20:55	gnuvince_	I'm afraid I'm not gonna make it through this class
20:55	p_l	pity that they removed integration from HS math curriculum before I entered my last two years...
20:56	p_l	jbondeson: I always assumed that integration is harder :)
20:56	cooldude127	it is
20:56	cooldude127	but integral signs are more weapon shaped
20:57	gnuvince_	ok
20:57	jbondeson	integration is only tough when you start throwing in non-polynomials, then you just start reaching for the integration tables.
20:57	gnuvince_	Here's an exercise I'm working on, and I can't get to the final solution: http://mathbin.net/5831
20:57	gnuvince_	Could anyone hint me to my next logical step?
20:57	jbondeson	god bless LaTeX
20:58	gnuvince_	durka42: what is it?
20:58	durka42	"baby, i wish i were your derivative so i could lie tangent to all your curves" or something along those lines... i told you it was terrible
20:58	jbondeson	which problem are you working on, there are a lot of functions there
20:58	p_l	since we started mixing math and love... http://xkcd.com/55/
20:59	jbondeson	or is that your work
20:59	durka42	gnuvince_: what are you working towards, just the derivative of f(x)?
20:59	gnuvince_	jbondeson: it's my development. I need to find the derivative of f(x) (at the top) and the next lines are the steps I took so far
20:59	jbondeson	ah
20:59	cooldude127	gnuvince_: i think you've pretty much found it
20:59	durka42	i think you've found it, haven't you
20:59	durka42	you could simplify a little if you wanted to
20:59	cooldude127	gnuvince_: maybe could be simplified slightly, but not much
20:59	cooldude127	durka42: damnit!
21:00	gnuvince_	The answer is apparently: 2(6x^2 + 1)^3(54x^2 - 192x + 1)
21:00	gnuvince_	But I don't know how to get there.
21:01	jbondeson	you can pull out the (6x^2 + 1)^3 from both terms
21:01	jbondeson	along with the 2
21:01	cooldude127	gnuvince_: what jbondeson said
21:01	jbondeson	also use the & = & to align your equals signs =P
21:02	gnuvince_	jbondeson: thanks for the help and for the tip :)
21:02	gnuvince_	I'll try it out
21:02	jbondeson	after you factor out you cna then simplify
21:02	jbondeson	you had all the hard parts done
21:02	cooldude127	i remember the good old days of derivatives and integrals. now i'm stuck with matrices and vectors
21:02	jbondeson	linear algebra?
21:02	cooldude127	jbondeson: yes
21:03	jbondeson	i had a LA test where we were doing LU factorization on non-trivial matricies of 9x9 dimensions, it was murder
21:03	jbondeson	all by hand of course
21:03	jbondeson	no calculators allowed
21:04	cooldude127	jbondeson: that's awful
21:04	jbondeson	i got a B+ because i didn't reduce all my 5-digit fractions
21:04	cooldude127	lol
21:05	gnuvince_	jbondeson: oh thanks so much
21:05	jbondeson	"you can reduce 34325/64230, sorry -5 pts"
21:05	ayrnieu	,34325/64230
21:05	clojurebot	6865/12846
21:05	cooldude127	lol
21:06	cooldude127	well they were obviously both multiples of 5
21:06	gnuvince_	Here's another more general question: have you guys ever taken a class by correspondance?
21:06	cooldude127	no
21:06	gnuvince_	I'm finding it to be a lot harder and frustrating than an in-class course would be.
21:06	jbondeson	i wonder if (.hashCode) will work for the priority function of a treap...
21:06	ayrnieu	,(/ (/ 34325 5) (/ 64230 5))
21:06	clojurebot	6865/12846
21:06	ayrnieu	well, that's not useful :-)
21:06	cooldude127	jbondeson: what purpose would that serve
21:07	jbondeson	gnuvince_: it is. (this will make me sound very young) my mother actually just finished up her degree via correspondence in accounting and it was horrible for her.
21:07	jbondeson	cooldude127: treaps are randomized BSTs
21:07	jbondeson	you need a fairly random number for priority
21:08	cooldude127	jbondeson: oh yeah, that's right
21:08	gnuvince_	jbondeson: I am taking this class to get my math credits to go to university, but this is not helping me keep my motivation
21:08	jbondeson	i'm just concerned about it being random enough
21:08	cooldude127	jbondeson: i haven't actually learned them, just looked at the wikipedia page one time
21:08	jbondeson	,(hash '(1))
21:08	clojurebot	32
21:08	cooldude127	jbondeson: what about actually using a random number?
21:08	jbondeson	,(hash '(2 3))
21:08	clojurebot	1026
21:08	jbondeson	cooldude127: i would like to use something deterministic to utilize memoziation
21:08	cooldude127	oh
21:09	jbondeson	using lazy evaluation with memoization will allow for proper amortized costs
21:09	cooldude127	,(hash 2)
21:09	clojurebot	2
21:09	cooldude127	,(hash '(2))
21:09	clojurebot	33
21:09	jbondeson	yeah, that's the part i'm concerned about
21:09	cooldude127	jbondeson: hash codes for numbers aren't random
21:10	blbrown	is there proxying involved for java.lang objects like string. for example (def a "kljdfklsdjf") looks like type string, but is there a proxy between java.lang.String and the one represented there
21:10	jbondeson	i don't think that should matter too much, because you're not likely to be using contiguous real numbers in a treap
21:10	cooldude127	blbrown: clojure uses java.lang.String
21:10	jbondeson	,(hash 4.23)
21:10	clojurebot	1588116073
21:10	cooldude127	jbondeson: oh ok
21:10	cooldude127	blbrown: clojure uses java data types anywhere possible
21:10	jbondeson	blbrown: no, it's a java string
21:11	jbondeson	proxies are only used for dynamic objects that need to implement certain interfaces.
21:11	jbondeson	there are very few in core clojure.
21:11	blbrown	cooldude127, that is interesting, because I can call (first "klsjflksd" )
21:11	cooldude127	blbrown: clojure implements first on strings
21:11	jbondeson	futures use them , but when they get stable the proxy will likely be removed.
21:12	cooldude127	blbrown: any of the seq functions work on strings
21:12	blbrown	jbondeson, it is just interesting how clojure treats types
21:12	jbondeson	rich was just really smart ;_
21:12	jbondeson	;) even
21:12	cooldude127	blbrown: clojure isn't object-oriented, so functions can operate on anything they want
21:12	blbrown	simple yet powerful
21:12	cooldude127	i agree, rich is very smart
21:13	jbondeson	blbrown: it's amazing how much you can do with a hash map. cooldude127 can show you his avl tree that only uses linked hash maps and no "data types" as it were
21:13	blbrown	OK here is an example, I am pretty sure with ABCL/Common Lisp, you don't have this kind of interoperability. Clojure handles different types seamlessly
21:14	jbondeson	i hate to admit it, but being on the jvm allows you to do some very handy things
21:14	cooldude127	blbrown: the difference is clojure was built from the ground up on the jvm
21:14	cooldude127	abcl had to lug around CL compatibility
21:15	jbondeson	how can acm not have anything on treaps in their digital library? what am i paying $200 a year for >=/
21:15	blbrown	hehe
21:15	cooldude127	blbrown: if you're interested in what jbondeson mentioned about the avl trees: http://github.com/cooldude127/clojure-code/blob/6401c6eb0b9a1fc087d17cd1999f49658d312375/structures/avl_tree.clj
21:15	cooldude127	damnit github
21:15	cooldude127	long-ass urls
21:16	jbondeson	watch out, or clojurebot will start tinyurl'ing everything again
21:16	blbrown	cooldude127, are you talking to the wrong person
21:16	cooldude127	lol
21:16	jbondeson	hiredman is just waiting for the day!
21:16	cooldude127	blbrown: no. jbondeson mentioned this to you
21:16	jbondeson	that was an example of how the "type" system in clojure works
21:17	jbondeson	cooldude127 just did a very clean implementation that gets the point across nicely
21:17	cooldude127	well, clojure does have a kind of type system, but often it's unnecessary
21:17	jbondeson	well, yeah
21:17	cooldude127	jbondeson: the only reason i wrote this was to learn how to write an avl tree. then i had to do it in java
21:17	cooldude127	awful
21:17	jbondeson	but you don't use it much unless you want to leverage multimethods.
21:17	cooldude127	yeah
21:18	jbondeson	cooldude127: come now, all the persistent data structures were implemented in Java by rich.
21:18	jbondeson	think of THAT pain
21:18	blbrown	cooldude127, yea, I would have written it in clojure and then code generated the java
21:18	cooldude127	yeah i applaud and admire him
21:18	cooldude127	blbrown: the idioms are different
21:19	cooldude127	the clojure version is purely functional
21:19	jbondeson	i've been tempted to do some persistent data structure programming in C# and then i think of the pain it will cause me...
21:19	cooldude127	yeah screw that
21:20	jbondeson	one day people at my office will come in and half the codebase will be in clojure and it will be glorious.
21:20	cooldude127	lol
21:20	cooldude127	i have a computer programming project for calculus 3, so i'm writing all kinds of linear algebra stuff in clojure
21:21	jbondeson	i love programming projects for non-programming classes.
21:22	cooldude127	jbondeson: me too
21:22	cooldude127	it's really fun to be in class writing the code to do the stuff we are currently going over in class
21:22	cooldude127	also a good way to actually learn it
21:23	jbondeson	forces you to think about the nitty-gritty
21:23	cooldude127	btw has anybody given a go at symbolic math in lisp?
21:23	jbondeson	plenty
21:23	cooldude127	jbondeson: yeah, apparently row-reduction is way more difficult for a computer than a person
21:23	p_l	cooldude127: many had given a go, including textbooks (PAIP comes to mind)
21:24	cooldude127	p_l: what's paip?
21:24	cooldude127	i just found cl-symbolic-math on github lol
21:24	jbondeson	mathematical functions are so regular that symbolic math parsers are actually very similar to lisp readers.
21:24	p_l	cooldude127: "Paradigms of Artificial Intelligence Programming: Case Studies in Common Lisp"
21:24	cooldude127	oh god
21:24	jbondeson	AI Bible
21:25	jbondeson	Made by god.
21:25	ayrnieu	coolude - http://maxima.sourceforge.net/
21:25	jbondeson	i.e. Norvig
21:25	p_l	and a kind of advanced CL textbook :)
21:25	cooldude127	oh wow
21:25	cooldude127	i opened up a can of worms i wasn't ready for
21:26	jbondeson	you want a can of worms you aren't ready for just go look up "A New Kinda of Science" by Wolfram
21:26	jbondeson	THE Wolfram that is.
21:26	p_l	AFAIK one of the first apps to tackle symbolic math was "Student"? ca. 1960s?
21:26	cooldude127	oh no
21:26	ozy`	,`('foo unquote 'bar)
21:26	clojurebot	((quote sandbox/foo) clojure.core/unquote (quote sandbox/bar))
21:27	ozy`	oh cool
21:27	jbondeson	symbolic math and lisp are like kissing cousins.
21:27	ozy`	,'`(foo ~bar ~@baz)
21:27	clojurebot	(clojure.core/concat (clojure.core/list (quote sandbox/foo)) (clojure.core/list bar) baz)
21:27	cooldude127	jbondeson: what exactly do you mean by that?
21:28	p_l	BTW, people here interested in making clojure equivalent of clbuild?
21:28	ozy`	,'`foo
21:28	clojurebot	(quote sandbox/foo)
21:28	ozy`	weird
21:29	cooldude127	p_l: as in a package manager?
21:29	jbondeson	cooldude127: i wouldn't be at all surprised if one of the first applications McCarthy came up with for Lisp was symbolic math
21:29	cooldude127	like a version of asdf that is not crappy as hell
21:29	cooldude127	jbondeson: it seems like a natural with symbols being there and all
21:30	jbondeson	asdf... ewwww
21:30	jbondeson	asdf is about pain
21:30	p_l	cooldude127: ASDF is a build system. clbuild was for actually downloading the stuff in the first place
21:30	ozy`	jbondeson: isn't that why he made it?
21:30	jbondeson	i belive so
21:30	cooldude127	p_l: ok like a less crappy asdf-install
21:30	ayrnieu	what's painful about ASDF, jbondeson?
21:30	cooldude127	ayrnieu: EVERYTHING
21:31	jbondeson	yes, i do believe that the question to be asked is "What is NOT painful about ASDF"
21:31	p_l	AFAIK Lisp was conceived as a nice theoretical tool. Then a certain student had gone to McCarthy after a lecture, and said "Hey, if I implement (eval ...), I'll get the whole language!"
21:32	ozy`	yeah
21:32	p_l	as for now, I've got a simple script that will build CLASSPATH so that all jars that are lying in certain directory are included
21:32	p_l	(this script is a wrapper for clojure)
21:33	jbondeson	.emacs will do that for you in 1 elisp line =P
21:33	ayrnieu	cooldude - OK, so everything except for 'defining systems, compiling them, loading them, putting them where ASDF can find them'. Well, you can get a little bit of code to do that last part, or you can use asdf-install which does that too. It's so painful, it says "hey, do you want me to install this locally or system-wide? Oh, OK." And then it sort of whines about GPG.
21:33	p_l	jbondeson: Yeah, and I'll load up Emacs to do it for me on every invocation on cmdline? /bin/sh is still smaller :P
21:33	stimuli	hi
21:34	jbondeson	p_l: wait, emacs is an operating system... what is a shell?
21:34	p_l	jbondeson: Part of that Exokernel that runs Emacs
21:34	stimuli	an easy way to copy files inside of emacs ?
21:34	ayrnieu	stimuli - dired.
21:34	stimuli	M-x shell
21:34	jbondeson	so confused
21:35	stimuli	wrote my first is-test code ... It is pretty good
21:35	stimuli	I like that it isn't hideously complicated
21:35	ayrnieu	p_l - by simple script, do you mean: for x in some/dir/*.jar; do CLASSPATH=$CLASSPATH:$x; done ?
21:35	jbondeson	emacs loves you... why would you ever abandon it?
21:35	stimuli	there are things besides emacs ???
21:35	p_l	ayrnieu: something like that (I've got some additional things loaded, like switching debugging options on and off etc.)
21:35	stimuli	don't even say that
21:36	cooldude127	alright well great, i started reading code for symbolic math and now i've ruined my life ;)
21:37	durka42	there's vim :)
21:37	hiredman	mmmm vim
21:37	p_l	ayrnieu: Now I'm writing something to actually download/upgrade/compile clojure libs and then symlink them to said dir :)
21:38	p_l	at the moment it's going to be pure shell script, because I pretty well know that it's not rare for me to fuckup my install :)
21:39	gnuvince_	,seen rhickey
21:39	clojurebot	java.lang.Exception: Unable to resolve symbol: seen in this context
21:39	Chouser	~seen rhickey
21:39	clojurebot	rhickey was last seen in #clojure, 199 minutes ago saying: that's the only promise made by the sequence fns
21:40	jbondeson	Chouser to the rescue.
21:40	gnuvince_	Thanks
21:41	cooldude127	this might also work
21:41	gnuvince_	I was wondering if he'd seen the report on byte, short et al.
21:41	cooldude127	clojurebot: seen rhickey?
21:41	clojurebot	rhickey was last seen in #clojure, 200 minutes ago saying: that's the only promise made by the sequence fns
21:41	Chouser	no future in lazy
21:41	jbondeson	damn do i love academia: "On Using Condiditonal Rotations and Randomized Heuristics for Self-Organizing Ternary Search Tries"
21:42	cooldude127	jbondeson: oh my god
21:42	stimuli	I'd call it "Tries that ROCK!" .. my professors be damned
21:42	cooldude127	lol
21:43	stimuli	I've been pouring through like 3490239423094 journal articles on Datalog
21:43	stimuli	they're sometimes ... dense
21:44	jbondeson	i bet if i read this paper this guy took a 30 year old algorithm and said "What if we don't rotate all the time?" and wrote a 7 page paper on the topic
21:45	stimuli	hmmm
21:46	stimuli	well ... there are more students than ideas I suppose
21:46	jbondeson	not everyone can be Okasaki
21:46	stimuli	no
21:46	p_l	stimuli: and big amount of students are not really that keen on making new stuff
21:47	stimuli	I suppose I shouldn't criticize ... I can't fill up a twitter post
21:53	Chouser	This appears to be a infinite loop in lazy branch: (take-while #(>= % 0) (repeatedly #(.read stream)))
21:55	notyouravgjoel	I need to create the powerset of a set, and my current implementation (based off of the contents of SICP) is killing my application with memory use. Any suggestions for a speedy powerset implementation?
21:56	jbondeson	i think there's a powerset in contrib... or at least someone submitted on to the group
21:56	ayrnieu	if you paste your current implementation, maybe someone can help you with memory use.
21:56	notyouravgjoel	thanks
21:57	Chouser	Is that the same as clojure.contrib.combinatorics/subsets ?
21:58	jbondeson	Chouser: yes, just found the clojure.contrib issue
21:58	stimuli	has anyone put together a graph library ?
21:58	notyouravgjoel	where do i find clojure.contrib references?
21:58	ayrnieu	notyour - there's a link on clojure.org
21:59	jbondeson	http://clojure-contrib.googlecode.com/svn/trunk/
21:59	cooldude127	stimuli: which kind of graph? the data structure? or the chart kind?
22:00	stimuli	data structure
22:00	stimuli	traversals .. strongly connected components and that stuff
22:00	cooldude127	stimuli: then no, but i might do it. i'm in a data structures class right now and we're about to learn graphs
22:00	stimuli	I'd love a lazy post-order stream ... I've written a non-lazy one
22:00	stimuli	but it is non-obvious how to make it lazy
22:01	cooldude127	stimuli: obviously, or you would have done it ;)
22:01	jbondeson	stimuli: add cheetos
22:01	stimuli	:P
22:01	stimuli	yeah
22:01	lisppaste8	notyouravgjoel pasted "powerset" at http://paste.lisp.org/display/75390
22:01	stimuli	is powerset the same as all subsets ?
22:01	notyouravgjoel	my current implementation, btw
22:01	notyouravgjoel	yes
22:02	stimuli	there is one in the combinatorics library in contrib
22:02	jbondeson	which is vastly more comple
22:02	jbondeson	+x
22:03	stimuli	contrib has some cool stuff in it
22:03	stimuli	I'm prolly going to use monads soon
22:03	jbondeson	honestly your best bet is to pull down contrib and use clojure.contrib.combinatorics/subsets
22:04	stimuli	yeah
22:04	stimuli	to "seriously" use clojure .. you pretty much need contrib
22:04	stimuli	its kinda becoming a standard library
22:04	cooldude127	yeah for reals
22:05	Chouser	this is broken in lazy: (take-while #(>= % 0) (range 9 -9 -1))
22:05	stimuli	hmmm
22:05	jbondeson	cool kids reimplement all of contrib ... in an hour B)
22:05	stimuli	chouser : do you think lazy will become official ?
22:05	stimuli	<-- not a cool kid, evidently :)
22:05	jbondeson	damn you enter key
22:05	Chouser	My guess? yes. But that's just a guess.
22:06	stimuli	I guess I'll have to learn it then :)
22:07	Chouser	range is broken
22:08	Chouser	oh. range uses take-while.
22:09	stimuli	I just hope we don't end up with stream ... destructive streams are evil
22:10	cooldude127	stimuli: i don't think rich really likes streams
22:10	cooldude127	because of the whole state thing
22:10	stimuli	good
22:10	stimuli	yeah
22:10	stimuli	ocaml had stream
22:10	stimuli	they were a PITA
22:10	jbondeson	ahhhhh ML
22:10	cooldude127	ocaml state doesn't it?
22:10	jbondeson	ML, O'Caml, F# god bless them
22:10	cooldude127	s/ocaml/ocaml has/
22:11	stimuli	yeah .. it's ml with object .. more or less
22:11	cooldude127	i personally just hated the syntax of ocaml
22:11	stimuli	or maybe sml with objects ... I'm not sure
22:11	cooldude127	;; <- wtf?
22:11	jbondeson	hah
22:11	stimuli	or the dots :)
22:11	stimuli	remember the dots ?
22:11	cooldude127	oh god
22:11	jbondeson	sorry but ':=' is still the worst
22:11	stimuli	. ... or was it .
22:11	gnuvince_	*.
22:12	cooldude127	jbondeson: i don't mind :=
22:12	jbondeson	screw pascal
22:12	stimuli	R uses <-
22:12	stimuli	which is kind of cool if you like typing
22:12	jbondeson	i loath the shift key
22:12	cooldude127	jbondeson: smalltalk also uses :=
22:12	jbondeson	cooldude127: wait is that a plus? ;)
22:12	cooldude127	jbondeson: smalltalk is win
22:13	cooldude127	if i have to do oo, it better be in smalltalk
22:13	stimuli	yeah ... smalltalk is lovely and wonderful
22:13	jbondeson	so sad
22:13	jbondeson	great ideas, horrid implementation
22:13	cooldude127	jbondeson: i get screwed cuz i try to use Emacs keybindings in visualworks
22:14	cooldude127	and i end up deleting all the code i just wrote
22:14	gnuvince_	Smalltalk environments are bad.
22:14	gnuvince_	They should do like Factor and open an external editor to edit code.
22:14	cooldude127	yeah it's the main reason i don't use it more
22:14	Chouser	rhickey: I've got a tiny patch to fix a paren typo in take-while. You want the whole group/issue process?
22:14	jbondeson	cooldude127: then you tried to do C-x _?
22:14	Chouser	this is in the lazy branch.
22:15	cooldude127	jbondeson: yeah i tried C-x C-s and the C-x killed everything
22:15	jbondeson	hahaha
22:15	cooldude127	jbondeson: save often ;)
22:15	jbondeson	this is exactly why you should never leave emacs
22:15	cooldude127	jbondeson: i could probably do that with gnu smalltalk
22:15	cooldude127	it has an emacs mode
22:17	cooldude127	anyway, what language is this channel about again?
22:17	gnuvince_	heh
22:17	jbondeson	haskell?
22:17	jbondeson	i forget...
22:17	stimuli	the smalltalk environments were both cool and sucky at the same time
22:17	stimuli	BCPL ?
22:17	cooldude127	jbondeson: that's pretty close
22:17	gnuvince_	Ah, Haskell :)
22:17	cooldude127	jbondeson: at least you picked a functional language
22:17	jbondeson	still miss patern matching
22:17	cooldude127	jbondeson: me too
22:17	gnuvince_	If it wasn't for Clojure, I'd be into Haskell full time
22:18	cooldude127	i couldn't make haskell be useful
22:18	cooldude127	cuz i still don't fully understand monads
22:18	jbondeson	monads are a whole lot of philosophy and not much science...
22:18	stimuli	I kinda do understand monads .. er .. most of the time ... well ... kinda
22:18	gnuvince_	cooldude127: the problem with monads is that they're simple and can be used to do crazy things
22:19	cooldude127	gnuvince_: yeah i could never figure out just how
22:19	cooldude127	i tried
22:19	cooldude127	then i found better ways to spend my time
22:19	gnuvince_	One problem with monads is that the same syntax can have vastly different effects depending on the type being worked with
22:19	cooldude127	true true
22:19	stimuli	yeah .. I remember on of walder's early articles where he changed the eval order of a program (completely reversing it) just by changing the monad
22:20	cooldude127	oh god
22:20	stimuli	I mean .. it's cool
22:20	jbondeson	you know what the only problem with persistent datastructures is? having to think about all the bloody copying.
22:20	stimuli	yeah
22:20	notyouravgjoel	sorry for being so... bad at this, but how exactly do I used contrib? I checked out the svn and created clojure-contrib.jar by running ant
22:20	ayrnieu	jbondeson - think about all the safely shared data.
22:20	stimuli	we spend like 3290409230984 hours today tracking down a bug that just couldn't happen in FP
22:21	ayrnieu	notyour - add the .jar to CLASSPATH
22:21	notyouravgjoel	ah k
22:21	gnuvince_	stimuli: what kind of days do you have on your planet?
22:21	jbondeson	notyouravgjoel: are you using emacs?
22:21	stimuli	gnu : long ones
22:21	stimuli	:)
22:21	notyouravgjoel	yes
22:21	notyouravgjoel	emacs
22:22	gnuvince_	Well I'm going to bed
22:22	gnuvince_	Hopefully Rich will see my issue tomorrow
22:22	stimuli	not : in your .emacs there is prolly some place where you set the classpath for whatever slime/mode/otherwise you are using
22:22	notyouravgjoel	ah, not using slime; never bothered to get it working
22:22	jbondeson	add it to your swank-clojure-extra-classpaths
22:22	stimuli	not : does M-x run-lisp or run-clojure work for you ?
22:23	notyouravgjoel	no
22:23	stimuli	so how do you run code ?
22:23	stimuli	from shell ?
22:23	notyouravgjoel	yep
22:23	stimuli	oh
22:23	cooldude127	notyouravgjoel: maybe try technomancy's clojure-mode clojure-install function?
22:23	stimuli	there are some not-quite-slime major modes out there
22:23	stimuli	that let you run your code in emacs
22:23	stimuli	more or less slime like but easier to setup
22:24	notyouravgjoel	I'm fine with this, for now
22:24	lisppaste8	jbondeson pasted "add classpath" at http://paste.lisp.org/display/75392
22:24	jbondeson	that reeeaaaaly helps
22:24	stimuli	your productivity will go up a lot ..... when you have some free time it is worth pursuing
22:24	notyouravgjoel	just because I have a deadline with this thing, tomorrow at midnight
22:24	stimuli	ah
22:24	jbondeson	add that to .emacs and you can M-x clojure-add-classpath anything
22:25	danlarkin	Chouser: I pulled represent and invoke-templatetag into a separate (3rd) file. Ugly, but working, solution
22:25	stimuli	not : do you use Java ? know how classpaths work ?
22:25	lisppaste8	jbondeson annotated #75392 with "more emacs goodness" at http://paste.lisp.org/display/75392#1
22:25	notyouravgjoel	ehh, I believe I do. Its simply where java searches for classes, if not in current directory, right?
22:25	stimuli	yeah
22:25	jbondeson	those two together will allow you to not have to restart emacs when you want to screw with your classpaths
22:25	stimuli	so you do java -classpath clojure.jar:clojure-contrib.jar:whateverelse.jar ....
22:26	ayrnieu	notyour - it's a list of .jars and directories that java searches for classes in, yes.
22:26	stimuli	you might have to use a ; instead of a :
22:26	notyouravgjoel	ahh
22:26	stimuli	you can put them in an environment var CLASSPATH
22:26	stimuli	and then Java will find them
22:26	stimuli	which helps when you have a zillion jars
22:27	cooldude127	jbondeson: your code there now reveals why my classpath addition didn't work until i restarted emacs
22:27	notyouravgjoel	ah, added it
22:27	notyouravgjoel	but still no good
22:27	jbondeson	cooldude127: can't take credit, i sooo lifted that off the internet
22:28	cooldude127	jbondeson: either way, i now know why it didn't work :)
22:28	stimuli	not : java -help :)
22:29	notyouravgjoel	well anywya, I'm currently specifying it via -cp
22:29	notyouravgjoel	ie, im running
22:29	stimuli	not : awesome!
22:29	notyouravgjoel	java -agentlib:yjpagent -Xms128m -Xmx256m -cp jline-0.9.94.jar:clojure.jar:clojure-contrib.jar jline.ConsoleRunner clojure.lang.Repl
22:29	notyouravgjoel	and.. nothing, still
22:29	stimuli	oh
22:30	stimuli	are all the jars in your local directory ?
22:30	notyouravgjoel	yep
22:30	stimuli	is there an error message ?
22:30	notyouravgjoel	wow, jar -t clojure-contrib.jar hangs
22:30	notyouravgjoel	for quite a while
22:30	stimuli	try jar -tf
22:30	stimuli	:)
22:31	notyouravgjoel	ah
22:31	stimuli	it was waiting on stdin
22:31	notyouravgjoel	makes sense, ahha
22:31	Chouser	danlarkin: hm, ok.
22:31	notyouravgjoel	wait.. these are all .clj files
22:31	stimuli	that is ok
22:31	lisppaste8	p_l pasted "Ugly clojure startup script" at http://paste.lisp.org/display/75393
22:31	stimuli	to get *.class files in clojure-contrib.jar you have to tell ant where clojure.jar is
22:32	stimuli	when you build contrib
22:32	stimuli	but it should still work w/ just the .clj files .. just loads slower
22:32	notyouravgjoel	mm, okay
22:32	notyouravgjoel	I'll check it out
22:32	stimuli	yeah .. play around w/ it
22:34	stimuli	well .. I'm turning in .. goodnight (or afternoon or whatever) everyone
22:34	notyouravgjoel	thanks for the help
22:34	notyouravgjoel	ah
22:36	p_l	Question: When I attempt to autocomplete symbols in SLIME, I get "funcall: Synchronous Lisp Evaluation aborted"
22:36	cooldude127	p_l: perhaps your slime or swank-clojure is old
22:36	cooldude127	p_l: i had that and then updated
22:36	notyouravgjoel	how do I set the clojure.jar path with ant?
22:40	jbondeson	notyouravgjoel: notyouravgjoel: for clojure.contrib "-Dclojure.jar=/path/to/clojure.jar"
22:40	jbondeson	whops
22:40	notyouravgjoel	ah thanks
22:41	notyouravgjoel	oh god
22:41	notyouravgjoel	it still wont work
22:41	jbondeson	?
22:42	notyouravgjoel	actually, I think classpath isn't working properly in any case
22:42	notyouravgjoel	take it back
22:43	notyouravgjoel	it is, itself, but clojure-contrib.jar isn't working one pit
22:44	notyouravgjoel	so, I ran "ant -Dclojure.jar=clojure.jar"
22:45	notyouravgjoel	(i copied clojure.jar into clojure-contrib-read-only)
22:45	notyouravgjoel	then, copied clojure-contrib into my main clojure directory
22:46	notyouravgjoel	when running, I use
22:46	notyouravgjoel	java -agentlib:yjpagent -Xms128m -Xmx256m -cp jline-0.9.94.jar:clojure.jar:clojure-contrib.jar jline.ConsoleRunner clojure.lang.Repl
22:46	notyouravgjoel	java -agentlib:yjpagent -Xms128m -Xmx256m -cp jline-0.9.94.jar:clojure.jar:clojure-contrib.jar jline.ConsoleRunner clojure.lang.Repl
22:46	notyouravgjoel	ugh
22:46	p_l	Yeah! I've got Java symbol completion partially working!
22:47	notyouravgjoel	once the REPL starts, "(clojure.contrib.combinatorics/subsets '(1 2 3 4))" returns "java.lang.ClassNotFoundException: clojure.contrib.combinatorics (NO_SOURCE_FILE:1)"
22:47	notyouravgjoel	any ideas?
22:47	ayrnieu	notyour - (use 'clojure.contrib.combinatorics)
22:48	notyouravgjoel	ah, should have figured
22:49	notyouravgjoel	mm, are lambdas still not garbage collected?
22:50	cooldude127	p_l: did the update fix it?
22:52	p_l	cooldude127: not only update - Java object completion was added outside it. Clojure objects _were_ fixed by it
22:52	ayrnieu	notyour - they are.
22:53	notyouravgjoel	k
22:53	cooldude127	p_l: cool
22:55	p_l	cooldude127: Now I need to experiment a little more so that I'll get completion a'la NetBeans :P
22:55	danlarkin	Chouser: uh oh! now I have a love triangle of (require ) forms. I feel like this is something I shouldn't have to deal with
22:55	cooldude127	danlarkin: sounds like you've got something wrong
22:55	danlarkin	cooldude127: won't be the last time :)
22:56	cooldude127	lol
22:59	notyouravgjoel	haha, my own powerset implementation is significantly faster than the contrib version
22:59	cooldude127	notyouravgjoel: WOOHOO! screw standard libraries
23:00	notyouravgjoel	pff, at least when the textbook version is 3x as fast as the std lib version
23:01	cooldude127	lol
23:03	notyouravgjoel	Soo, back to my original question : any idea how to optimize this: http://paste.lisp.org/display/75390
23:06	notyouravgjoel	I actually do only use a small portion of the entire powerset, but I don't know an effective way of pruning the execution tree
23:06	notyouravgjoel	I realize that creating a particularly large powerset is very hard
23:07	notyouravgjoel	(has n^2 elements for a set of length n)
23:10	Chouser	notyouravgjoel: with a quick glance, that appears to be pretty lazy
23:10	Chouser	it should only compute what you use.
23:11	Chouser	(seq set) is more correct than (nil? set)
23:11	Chouser	or just (if set ...)
23:11	notyouravgjoel	I don't understand lazyness entirely
23:12	notyouravgjoel	or well, I get the gist
23:12	notyouravgjoel	but, how do I apply it to this problem?
23:12	Chouser	'set' is the name of a builtin function, though, so you might choose a different name for that arg
23:12	notyouravgjoel	can I creat the powerset, and then use some filter to only ahve what I want?
23:12	Chouser	well, you said you only need a "small portion". which portion?
23:13	notyouravgjoel	I filter the problem to make it smaller, not using any sets that have greater than half the original set's amount of sets
23:14	notyouravgjoel	(thanks for your help by the way)
23:15	Chouser	hm, sounds like laziness might not help you much then
23:16	notyouravgjoel	yeah. It would be great, though
23:16	notyouravgjoel	I'll have to ponder the powerset function, I suppose
23:16	notyouravgjoel	maybe prune it a bit
23:16	Chouser	if you were to do (take 5 (powerset...)) it would only compute the first 5
23:16	notyouravgjoel	is it possible to do something like
23:16	Chouser	(assuming it's as lazy as I'm guessing by just looking at it)
23:16	notyouravgjoel	take a random 5?
23:17	Chouser	the 'rest' of a seq is lazy
23:18	Chouser	the only way to get to item n in a seq is to walk past and realize all of the items up to n
23:19	Chouser	so counting a lazy seq realizes the whole thing
23:20	Chouser	that means to get a fair random selection, laziness won't help. Though you could "flip a coin" on each item until you have as many as you want, leaving the rest unrealized.
23:20	notyouravgjoel	makes sense
23:20	notyouravgjoel	the problem is that this implementation goes...
23:21	notyouravgjoel	(powerset (range 1 4))
23:21	notyouravgjoel	([] (3) (2) (2 3) (1) (1 3) (1 2) (1 2 3))
23:21	notyouravgjoel	ah well
23:21	notyouravgjoel	so 1's only start getting added after the others
23:22	notyouravgjoel	ah well
23:22	notyouravgjoel	Thanks man =)
23:22	Chouser	It seems like you might be able to build your "less than half the length" constraint right into the function.
23:22	notyouravgjoel	I'll go think about it
23:22	Chouser	good enough.
23:22	notyouravgjoel	well see
23:23	notyouravgjoel	a powerset of a set of n elements is length 2^n
23:23	notyouravgjoel	cutting it in half == a new length of 2^(n-1)
23:23	notyouravgjoel	which only yields me an extra 1
23:23	notyouravgjoel	ie, i can now calculate the powerset of a set with 22 elements, whereas now I'm stuck at 21
23:24	notyouravgjoel	but yeah, that IS a good net improvement
23:25	notyouravgjoel	Ohhh wait, you gave me an idea!