#clojure – 2008-10-21

2008-10-21

00:00	crathman	is there a random function? (or do I need to use Java's?)
00:02	sohail	underneath, is lazy-cons an iterator?
00:02	arohner	crathman: use java's
00:03	arohner	sohail: what do you mean by iterator?
00:03	sohail	like Java's Iterator interface
00:04	arohner	it looks like LazyCons just implements the clojure seq interface, but seq is a java iterator
00:20	sohail	yep, that's what I'd expect
00:23	Chouser	crathman: or (rand-int 10)
00:23	Chouser	Java iterators mutate, don't they? Seqs don't.
00:23	crathman	Chouser: thanks
00:24	arohner	Chouser: ASeq.java has a function called iterate() that returns an Iterator
00:25	Chouser	ah, so they provide an iterator, but aren't iterators themselves?
00:25	arohner	looks that way. ASeq does not implement iterator
01:53	Pupeno	Good morning.
02:16	Lau_of_DK	Morning gents
05:46	Lau_of_DK	Is dotimes purely for side effects, or can I do something similar to :collecting i in it ?
06:10	Lau_of_DK	Anybody remotely awake?
06:10	tWip	yes
06:10	Lau_of_DK	Good, just checking, good to see you again :)
06:10	Lau_of_DK	(truth is, I just solved it)
06:14	ccmtaylor	Lau_of_DK: try for: (for [i (range 10)] i)
06:20	Lau_of_DK	user=> lst
06:20	Lau_of_DK	((1 2 3) (1 2 3 4) (1 2 4 5 6) (1 2 3 4 5))
06:20	Lau_of_DK	If I have a list of lists - How do I reduce it, so that I only retain the one with the longest count ?
06:27	hoeck	Lau_of_DK: (reduce #(if (< (count %) (count %2)) %2 %1) foo)
06:27	hoeck	oops, where foo == your list-of-lists
06:28	Lau_of_DK	And that works with more than 2 ?
06:29	hoeck	yes
06:29	Lau_of_DK	Thanks alot Hoeck!
06:31	alvin-x	would somebody mind commenting on the style of the code here: http://paste.lisp.org/display/68926
06:31	alvin-x	i started writing clojure yesterday
06:32	hoeck	Lau_of_DK: always a pleasure to help you!
06:32	Lau_of_DK	Glad you feel that way! :)
06:40	hoeck	alvin-x: looks good!, maybe convert the single-arg anonymous functions into #()-style for better readability
06:41	AlephInf	alvin-x: also you can say (ObjectName. bean-name) instead of the (new ..) if you prefer, Also, don't need the nil in the else of the (if .. ) since it defaults to nil anyway.
06:42	alvin-x	hoeck: i didn't see anything yet on clojure.org about #()-style... can you give me a link?
06:42	jdz	AlephInf: in which case one should use 'when'
06:43	jdz	and #( reader is not always better than fn
06:44	Lau_of_DK	Hoeck :) Can you lend a hand again please.
06:44	Lau_of_DK	user=> (combos 41)
06:44	Lau_of_DK	6
06:44	Lau_of_DK	user=> (reduce max (map #(combos %) (range 1 45)))
06:44	Lau_of_DK	java.lang.IllegalArgumentException: Wrong number of args passed to: combos--5722$fn
06:44	Lau_of_DK	I dont get it - I get this error whenever I call combos from another func
06:46	jdz	Lau_of_DK: you can safely replace (map #(combos %) ...) witch (map combos ...)
06:46	Lau_of_DK	oh
06:46	jdz	Lau_of_DK: that's in case it accepts only one argument.
06:46	jdz	Lau_of_DK: from the error message it looks like it wants more
06:46	Lau_of_DK	Same error
06:47	Lau_of_DK	As you can see from my manual call to combo, it takes 1 integer
06:47	hoeck	Lau_of_DK: can you paste combos, cause combos--5722$fn looks like an inner function of combos
06:47	Lau_of_DK	I sur ecan
06:47	jdz	just what i would suggest next...
06:48	lisppaste8	Lau_of_DK pasted "Prime components" at http://paste.lisp.org/display/68927
06:50	jdz	Lau_of_DK: look at your recur expression
06:50	jdz	oh wait, scratch that
06:51	Lau_of_DK	Could this be bcause partition might throw nil ?
06:51	jdz	but it seems to me that loop's and function's recur points conflict...
06:52	Lau_of_DK	If you try (combo 17) or (combo 41) you'll get good results
06:52	jdz	(which seems unlikely)
06:52	Lau_of_DK	I think its partition
06:52	Lau_of_DK	(combo 2) throws the same error
06:52	jdz	i think it's reduce
06:52	Lau_of_DK	How do I work around it ?
06:53	Lau_of_DK	thats right, it might be reduce
06:53	Lau_of_DK	yes
06:53	Lau_of_DK	that was it
06:53	hoeck	alvin-x: Anonymous function literal, http://clojure.org/reader
06:53	Lau_of_DK	by initiating th vector result with [(list n)]
06:54	Lau_of_DK	the problem is solved
06:54	Lau_of_DK	Thanks guys, you ask good questions
06:55	jdz	Lau_of_DK: the way you have written your function leaves no space for optimizations (e.g., memoization)
06:56	jdz	and I might be talking nonsense, of course
06:56	jdz	just ignore
06:56	Lau_of_DK	No no youre right
06:56	Lau_of_DK	Im working on that atm
06:57	jdz	Lau_of_DK: and instead of writing (doall (take-while ...)) you should have just written (take n)?
06:57	jdz	(or at least (doall (take n ...))
07:05	alvin-x	hoeck: thanks, that's a good place to shorten the fn
07:06	alvin-x	what's the usual tab/indent width level here... 2? or, is there some style guide?
07:06	alvin-x	ach, tab/indent width*
07:07	jdz	alvin-x: i'd guess it's the usual lisp style, which happens to be mostly 2 spaces
07:10	Lau_of_DK	jdz, do all forces computation, which speeds up things ALOT when we get into the higher numbers
07:21	alvin-x	i tried a lot of other dynamic JVM languages before sitting down to write something in clojure; i don't miss any of them now.
07:33	Chouser	alvin-x: did you see (doc bean)? It might help you out (or might not if I'm misunderstanding your goal)
07:38	Chouser	alvin-x: Dunno if you saw my comment before your client logged off. Do you know about (doc bean)?
07:39	alvin-x	Chouser: i saw it :) brb
07:40	Chouser	ok
08:01	alvin-x	Chouser: sorry, something came up at work. My goal is to have a few easy to use functions for calling remote JMX beans; you'll see the normal java code i'd have to write here: http://java.sun.com/javase/technologies/core/mntr-mgmt/javamanagement/best-practices.jsp#mozTocId805713 ("Code without a proxy").
08:03	alvin-x	(I can't use the proxy example there, as I don't have java interfaces. Not sure if it would work if I wrote the interfaces myself.)
08:05	alvin-x	I'm a middleware sysadmin, working on a short term solution for monitoring some app servers.
08:09	jdz	Lau_of_DK: my comment was not about doall, but about 'take' instead of 'take-while'
08:20	Lau_of_DK	can I assign a glob-var in a local scope, with some syntax tricks?
08:37	achim_p	Lau_of_DK: binding perhaps?
08:39	achim_p	(in case thread-locally shadowing the value is enough ...)
08:41	AWizzArd	Moin Leute
08:46	AWizzArd	btw, is it normal that it takes several hours until a posting appears in the google group?
08:46	jdz	when collecting stuff in loop, is it better to use cons + reverse at the end with lists or conj with vectors?
08:46	cemerick	AWizzArd: yeah, it can take a long time. It's sporadic, especially if you post via email.
08:47	AWizzArd	jdz: I would suggest vectors in general
08:47	H4ns	AWizzArd: i think the group silently drops postings from email addresses that are not members
08:47	lisppaste8	Lau_of_DK pasted "Optimize me! (primes)" at http://paste.lisp.org/display/68933
08:47	H4ns	AWizzArd: has bitten me multiple times, that.
08:47	AWizzArd	I see
08:47	Lau_of_DK	Friends - I need help! :)
08:48	AWizzArd	also when I joined the group.. it took hours until the member counter went up
08:48	Lau_of_DK	This seems to generate correct results. Try (combos 17) (combos 41) and so on. (euler-50 1000) also runs pretty descently. But the target is 1000000 and here I experience incredible slowdowns
08:48	Lau_of_DK	How do I optimize this ?
08:50	AWizzArd	cemerick: also a map could be nice for you.. you would not need to reverse it, depending on your algorithm
08:50	AWizzArd	and if you use just numbers it will have around O(1) access time, as the hashes will always go into unit buckets
08:51	lisppaste8	Lau_of_DK annotated #68933 with "Forgot a little something" at http://paste.lisp.org/display/68933#1
08:51	AWizzArd	Lau_of_DK: your indentation style is truly unique... ;-)
08:52	Lau_of_DK	Yes, its Notepad++ at its best - Sitting at work atm :)
08:53	AWizzArd	Btw, in slime+clojure the auto indentation style of IF is not so nice. Is that only for me?
08:53	Lau_of_DK	I'll tell you if you optimize my routine
09:02	AWizzArd	I guess this Euler stuff is only interesting to young people, and only for some time.
09:02	gnuvince	Project Euler is pretty fun to learn a language.
09:02	AWizzArd	yeah
09:03	AWizzArd	however, I mean it's nothing that you would like to do the coming four years
09:03	Lau_of_DK	achim_p, you can come work here, Ive resigned my position :)
09:03	achim_p	that's true for work in general, in my case
09:09	Lau_of_DK	any takers?
09:12	Lau_of_DK	Somebody do a Sieve or something! :)
09:15	AWizzArd	Lau_of_DK: can you develop a newsready for the Clojure google group? So that I can read messages and keep track of which I already read, without the need to use my browser for that?
09:15	AWizzArd	newsreader
09:15	Lau_of_DK	You dont like Thunderbird?
09:18	AWizzArd	i like it, but GG doesn't offer nntp
09:18	H4ns	AWizzArd: i read the group in my mail reader
09:18	H4ns	AWizzArd: nntp is so 1990ies
09:19	AWizzArd	H4ns: how do you do it?
09:19	H4ns	AWizzArd: with my eyes! :)
09:19	achim_p	Lau_of_DK: if you'd bother translating your algorithm to plain english, i'd give it a shot in a couple of minutes, but first i'll have to wrestle with john nash some more
09:19	H4ns	AWizzArd: you can have the group send the articles by mail
09:19	Lau_of_DK	AWizzArd, I had Googlegroup in my Thunderbird inbox
09:19	Lau_of_DK	Worked like a charm
09:19	Lau_of_DK	John Nash ?
09:20	achim_p	yeah, he's here on my desk
09:21	jdz	can anybody quickly tell how to create a Java byte array (byte[])?
09:23	AWizzArd	I just would have preferred if I could see all news ever written in that group.
09:23	achim_p	jdz: make-array with Byte/TYPE, or to-array on a collection of bytes should work
09:24	jdz	achim_p: well, what's the Byte/TYPE magic?
09:25	achim_p	that's java weirdness. there are some types which are both primitives and class-based types in java
09:25	achim_p	a byte isn't directly an instance of Byte, as far as i understand it
09:25	jdz	achim_p: ok, something like (make-array (. Byte TYPE) 4096), right?
09:26	Lau_of_DK	or (to-array ...)=
09:26	cemerick	(make-array Byte/TYPE 4096) is fine
09:26	jdz	Lau_of_DK: the point is i want to create an empty buffer..
09:26	cemerick	static fields and functions can use the slash notation
09:26	jdz	cemerick: oh, cool. didn't know that.
09:27	jdz	thanks guys.
09:27	jdz	(it works :)
09:29	lisppaste8	Lau_of_DK pasted "Optimize me! (primes)" at http://paste.lisp.org/display/68934
09:29	Lau_of_DK	Ok, thats pretty well commented, I think! :)
09:32	fogus	Has anyone used the J text editor in the past?
09:32	cemerick	fogus: isn't it just a vehicle for ABCL?
09:33	fogus	Yes, but I wonder if it would be possible (nevermind worthwhile) to use Clojure as a stand in
09:34	cemerick	possible, maybe. I don't remember there being much worthwhile in J itself (although ABCL is quite the conformance-engineering feat).
09:35	fogus	That was the crux of my question... usefulness.
09:35	cemerick	I think there could be a lot of possibility in building a framework on top of netbeans to allow for clojure-driven scripting, UI construction, etc. I'm sure the enclojure guys have thought a lot about this.
09:37	lisppaste8	jdz pasted "Reading .gz files (if anybody cares)" at http://paste.lisp.org/display/68935
09:39	jdz	i think the Clojure's slurp function could be better defined using slurp-byte-stream
09:40	jdz	maybe i'll look into java.nio if there's anything useful for this purpose
09:41	jdz	never done anything with it, though. only heard good rumors.
09:43	jdz	and then there is a bug in my code. it does not handle the case if the first read from stream returns -1
09:45	aperotte	hello everyone, had a question. I read in the api that there are some subtleties in how clojure deals with protected members of classes. If a library requires that I subclass and set a protected member that was inherited from a superclass, is this something that's possible?
09:46	aperotte	specifically, I'm trying to translate the Hello World jME tutorial into clojure http://www.jmonkeyengine.com/wiki/doku.php?id=starter:hello_world
09:47	lisppaste8	jdz annotated #68935 with "Updated version of slurp-byte-stream (almost untested)" at http://paste.lisp.org/display/68935#1
09:48	jdz	i long for fill-pointers a bit
09:51	Pupeno-G	Was there a special name to give to a file inside a jar so that Clojure would pick it up and run it automatically without a little main in Java?
09:52	Chouser	user.clj
09:52	Pupeno-G	Chouser: so, how does it work? there's a little main already in Clojure.jar?
09:55	Chouser	I think you still need to specify clojure.lang.Script on the command line
09:55	Pupeno-G	Chouser: oh, ok.
09:55	Pupeno-G	Understood now.
09:58	Chouser	aperotte: you can overload protected methods using proxy
10:46	aperotte	Chooser: thanks. I'm going to give it another go.
10:49	aperotte	Chooser: Are you saying that I should just override it to make it public? What's happening in my particular case is that there's a super-class that defines a protected member, that is inherited by the class the library expects me to extend. So the protected member isn't even defined in the class I'm inheriting from, it's defined in the class it inherits from.
10:50	rhickey	Hi all from Nashville airport - on my way back from Lisp 50
10:50	Chouser	aperotte: and is this member a method you want to override, or a field you're trying to set or something?
10:50	Chouser	rhickey: Hi! How'd it go?
10:51	aperotte	rhickey: I'm new, but hello anyway :)
10:51	rhickey	It went great. A really long day, I didn't talk until almost 8pm (started at 8:30 am)!
10:51	aperotte	Chouser: It's a field, that is itself an object that I'd like to call a method on
10:52	rhickey	Lots of seminal Lispers talked about the history, lots of reminiscing
10:53	Chouser	aperotte: ah. hm... I'm sure it's possible, but it may not be pretty.
10:53	AWizzArd	hi Rich
10:53	rhickey	Pascal Costanza's the only talk about current work in CL, Will Clinger on the state of Scheme
10:53	rhickey	Then, last, Clojure, about which many of them knew nothing
10:54	AWizzArd	this will change in 2009... it will be a well known secret :-)
10:54	asbjxrn	Don't know too much about the programme, but with a name like Lisp 50, it's not that strange that it was a look back.
10:54	aperotte	Chouser: haha ... thanks, that makes me feel better. I thought I was just missing something simple.
10:54	rhickey	Lots of skepticism at the start, but by the end I got so much good feedback , essentially validation that this is the right way to bring Lisp forward - make a break, address current problems etc
10:54	gnuvince	rhickey: what did the heavy weights (Gabriel, Steele) think?
10:54	asbjxrn	I thought it would be reasonably well known today, at least among lispers.
10:56	rhickey	There were lots of nice compliments during questions and after - had a long conversation with JoL White and others
10:56	gnuvince	rhickey: was your presentation video-taped?
10:57	gnuvince	(or video-digitalized, I'm not sure how to say that in a world where tapes almost don't exist anymore)
10:57	rhickey	I still have never gotten any feedback from Guy Steele - he left during the panel that followed my talks and wasn't at either of the Lisper dinners, although I saw him gesturing with 2 thumbs up during part of my presentation, but he may have just been agreeing with a particular point I made
10:58	rhickey	Dan Weinreb has become a fan, and was talking it up to many others before my talk
10:59	rhickey	Overall I think it went great - it represents such a sea change for that community but they were very gracious in accepting the new ideas
10:59	rhickey	Of course, in 45 minutes I can barely scratch the surface of Clojure
10:59	gnuvince	Good job :)
10:59	aperotte	Congratulations
11:00	Chouser	aperotte: you might need gen-class -- look at the :exposes feature
11:01	rhickey	There was videotaping and I signed a release... but I think the Boston Lisp talk was more comprehensive, if 4x as long
11:02	gnuvince	rhickey: it's still nice to have this, that's another Clojure post on reddit ;)
11:03	AWizzArd	grats
11:03	rhickey	thanks
11:03	lisppaste8	jdz annotated #68935 with "The correct version of slurp-byte-stream (hopefully :)" at http://paste.lisp.org/display/68935#2
11:04	aperotte	Chouser: thanks, I'll take a look
11:04	Chouser	rhickey: Sounds great. Soak it up! In another couple years you may have to be spending all your time on standards committees as everyone tries their own implementations of the Next Big Language. :-)
11:05	cemerick	rhickey: congrats on the trip/talk going so well.
11:05	rhickey	Chouser: I'm hoping the community will stay focused on the core implementation, as they have for Python and Ruby
11:06	cemerick	yeah, I think we can dispose with the standards committees :-P
11:06	rhickey	One thing was clear - standards stopped innovation in Lisp. Steele and Gabriel's talk enumerated so many dialects before the standards
11:07	Chouser	That's an excellent point. Did everyone "get" it?
11:07	AWizzArd	well yes, today it seems languages benefit from a dictator g
11:07	asbjxrn	Many dialects may not be what you want, though?
11:07	asbjxrn	Did scheme fare that much better?
11:07	H4ns	asbjxrn: as hardware and environments change, language innovation is needed to cope with that
11:08	Chouser	Well a good dictator is hugely imporant, but I think an open-source implementation makes it possible. The codebase is the standard.
11:08	rhickey	asbjxrn: It's less the dialects than the innovation - I think we can innovate in few dialects, but can't innovate a standard - it's fixed
11:08	asbjxrn	I definately agree.
11:08	asbjxrn	The trick is to get innovation without forks.
11:09	rhickey	Chouser: right, but differs from an actual standard in not being fixed on paper
11:10	rhickey	asbjxrn: Being open source and not wanting forks forces the core to be responsive to the community
11:12	asbjxrn	Yup, and so far you're doing great :) I'm not critizising (sp?), I'm just not sure that many lisp dialiects are better than one. I would assume that it would reduce the number of usable libraries.
11:13	rhickey	asbjxrn: well, I expect Scheme and CL to continue indefinitely
11:13	asbjxrn	But of course I do see the point that once the standard is printed, you're stuck. I just think that lisp may have been so fragmented that a common spec was good.
11:14	AWizzArd	In my opinion Clojure has the greatest potential to become more or less the best programming language.
11:15	gnuvince	I don't know about "best" (or even what it means), but I agree that if I had to put money on a relatively unknown language that would become extremely popular in the coming years, Clojure would be it.
11:16	AWizzArd	Since I began doing Common Lisp in 2003 this (Clojure) is what excited me most.
11:17	AWizzArd	This is especially amazing, because typically every 3 months someone comes to show his/her new Lisp, and it is always total useless $#\|~
11:18	asbjxrn	I thought that nick looked familiar...
11:19	Chouser	AWizzArd: you mean like arc? :-)
11:20	asbjxrn	Hang around in comp.lang.lisp for a while, and you'll see a handful, it's not just arc.
11:20	AWizzArd	Chouser: well yes, only that the development of Arc took just 4 years. Paul Graham managed to come up with a little improved scheme. Wow. sigh
11:21	gnuvince	I guess it takes a lot of time to come up with shorter names
11:21	Chouser	gnuvince: not just that -- it has a reader macro for [ ]
11:22	gnuvince	Chouser: right.
11:23	Chouser	:-)
11:34	asbjxrn	Uhm, clojure equivalent of progn?
11:34	jdz	do
11:36	asbjxrn	Thanks, I was sure I had tried that before with moderate success. Probably confused with a lazy sequence operation inside the do or something. That still trips me up every now and then
11:36	asbjxrn	(Having to use doall, for sideeffect stuff, that is.)
11:41	Chouser	Heh. "do" is the one use of "do" that's not for side-effects.
11:43	jdz	does anybody have a bit of sample concurrency code? i want to have a small pool of workers, then loop over my data set giving work to the first available worker (and waiting for a free one if all workers are busy).
11:46	AWizzArd	jdz: (pmap ...)
11:46	AWizzArd	it is like map, only that it divides the mapping to all available processors
11:46	AWizzArd	look at its code in the boot.clj
11:47	jdz	AWizzArd: thanks. i was already looking at java.util.concurrent.SynchronousQueue :)
12:00	AWizzArd	How can I count the number of occurrences of an object in a collection?
12:00	Chouser	(count (filter #{an-obj} coll)) ?
12:01	AWizzArd	Sure, but I mean there is nothing like that in the standard lib yet, right?
12:02	cemerick	no, but it seems like something simple enough to not include in the stdlib (IMO)
12:03	asbjxrn	That hash lookup trick is almost too sneaky, though.
12:04	Chouser	one of my gripes about CL (not that anyone should care what a noob like me thinks about CL) is the overwhelming number of built-in functions.
12:04	Chouser	asbjxrn: yes, except that it's "an idiom" now. It should be documented as such, I suppose.
12:04	cemerick	Chouser: agreed.
12:04	asbjxrn	You don't have to use them all ;)
12:04	jdz	Chouser: how is that different from java's standard lib?
12:04	gnuvince	Hmmm
12:04	gnuvince	After the API page, there ought to be an Idioms page
12:04	cemerick	I wouldn't say that there's anything sneaky about certain objects implementing IFn.
12:04	gnuvince	That'd be nice
12:05	Chouser	asbjxrn: no, but to write "correct" code you have to know about them all.
12:05	jdz	Chouser: how' s that different from Java' s standard lib?
12:06	asbjxrn	No, I like the hash as function idea, I use it a lot to lookup stuff. I've never thought of using it as an argument to filter, though. I had a little "huh" moment there.
12:06	Chouser	and it seemed to me that reading CL code without a manual at your fingertips would be impossible until I had been at it for a long time.
12:06	gnuvince	jdz: he meant built-in as in the global namespace.
12:06	jdz	gnuvince: what do namespaces have to do with it?
12:06	Chouser	yeah, the global namespace is certainly part of it.
12:07	gnuvince	jdz: look at PHP with its 4,000 functions in the same namespace.
12:07	Chouser	jdz: I'm not exactly a proponent of Java either, though I imagine the same question could be asked about any standard lib.
12:07	jdz	gnuvince: isn't that the problem of not having any name-separation capabilty?
12:08	jdz	Chouser: you can' t program C if you don' t know stdlib. same with CL.
12:09	Chouser	One little difference (and I don't know how important this is) is macros. In C or Java you may not know what a function does, but you know the args are evaluated and you may be able to "black-box" it for a moment in your mind while trying to get your bearins in the rest of the code.
12:09	Chouser	Not so with lisps.
12:11	jdz	Chouser: well, with lisp you have nice developement environment that can instantly tell you whether the symbol is a function or a macro
12:11	jdz	and then there are naming conventions.
12:11	jdz	and in most cases you don' t even care
12:12	Chouser	yeah, that's what I meant about "tools". I guess I was often reading code on a printed page.
12:22	AWizzArd	Is there a correct way to express (defn foo ([n []] 5) ([n [x & xs]] 6))? What I want is: (foo something empty-col) ==> 5 and (foo something col-with-something-inside) ==> 6
12:23	jdz	AWizzArd: you want functional language style pattern matching?
12:25	jdz	AWizzArd: you can go a bit along the way with destructuring, but there is no pattern matching in Clojure as far as i know
12:25	Chouser	(defn foo [n [x & xs :as allxs]] (if (seq allxs) 6 5))
12:26	Chouser	I believe that's idiomatic. I don't know of any "correct" name for xs or allxs.
12:28	asbjxrn	How is that different form (defn foo [n x] (if (seq x) 6 5)) ?
12:29	Chouser	it's not, unless you want to destructure the seq into x and xs
12:30	Chouser	which clearly aren't being used in this example, but I assumed AWizzArd wanted them for his actual code -- thought I'd show how to use :as in that case.
12:36	AWizzArd	asbjxrn: and also (seq x) is true only if x is a list. But not if x is a vector
12:38	Chouser	no, (seq []) is true
12:39	AWizzArd	ah okay, I read (seq? x)
12:39	asbjxrn	? In my repl (seq []) is nil.
12:39	Chouser	seq returns a seq object (acts like true) for any non-empty collection. For empty collections seq returns nil.
12:40	Chouser	yes, seq? is a bit different -- it returns true for ISequences like lists, lazy-cons, etc.
12:41	Chouser	and as you meant, seq? returns false for vectors, maps, etc. whether empty or not.
12:43	danlarkin	and is this reasonable? (seq? '()) == false
12:43	AWizzArd	Chouser: I think that's what I said.. (seq? x) is only true if x is a list.
12:44	Chouser	AWizzArd: or if x is a lazy-cons or other ISequence.
12:46	Chouser	danlarkin: hm, I think not. EmptyList probably should implement ISeq.
12:49	cemerick	Chouser: Yes, definitely. I've hit that one a couple of times.
12:51	Chouser	http://groups.google.com/group/clojure/browse_frm/thread/1ca1e57ce509b81c
12:51	Chouser	I guess I'm wrong.
12:51	cemerick	well, well
12:55	lisppaste8	achim annotated #68832 with "... with partitioning" at http://paste.lisp.org/display/68832#1
12:56	danlarkin	Interesting
13:05	lisppaste8	achim annotated #68832 with "correction" at http://paste.lisp.org/display/68832#2
13:22	fyuryu	is dispatch based on meta data considered a good practice?
13:30	Lau_of_DK	Evening gents
13:32	danlarkin	afternoon
13:35	billc	are there logs of the #clojure irc channel available?
13:36	fyuryu	billc: http://clojure-log.n01se.net/
13:36	billc	fyuryu: thanks!
13:36	duck1123	that really should be part of the channel's topic
13:37	Lau_of_DK	Has anybody had some luck optimizing my routine from earlier today ?
13:52	Lau_of_DK	Alright, lets say I have a nested list like this
13:52	Lau_of_DK	user=> (take 5 lst)
13:52	Lau_of_DK	(((1000 1001 1002) (4330 4331 4332) (7660 7661 7662)) ((1001 1002 1003) (4331 4332 4333) (7661 7662 7663)) ((1002 1003 1004) (4332 4333 4334) (7662 7663 7664)) ((1003 1004 1005) (4333 4334 4335) (7663 7664 7665)) ((1004 1005 1006) (4334 4335 4336) (7664 7665 7666)))
13:53	Lau_of_DK	And I want to filter out those lists wherein all 3 numbers are prime. (filter #(every? prime? %) ) doesnt work on nested lists, so what are my options?
13:56	danlarkin	nest your filters?
13:57	Lau_of_DK	Maybe. I'd prefer some sort of flatmap solution
13:57	Lau_of_DK	This wouldnt even be a problem if I could get partition to work with concat, its because Im conjoing seqs
13:58	devinus	dos clojure support OOP?
13:59	devinus	does*
13:59	danlarkin	devinus: it supports encapsulation, type hierarchies...
13:59	devinus	danlarkin: what about reflection capabilities?
13:59	danlarkin	and if you really need to you can make a custom object by using the gen-class functions
13:59	AWizzArd	devinus: Clojure gives you building material to implement oop the way you like it, if you want.
14:00	AWizzArd	devinus: but Paul Graham explained: functional programming + macros outperform oop
14:00	danlarkin	devinus: what sort of reflection? clojure has the concept of metadata
14:00	devinus	danlarkin: could you find the name of your function out within the function?
14:01	AWizzArd	devinus: you can simply use a map, where the keys are the fields of your class, and the information what class you want goes into metadata.
14:01	AWizzArd	devinus: Clojure supports macros. You can even write a function from which you can see the source code during runtime.
14:03	AWizzArd	just expand it into a defn and write the source code into the metadata
14:03	cemerick	devinus: remember that clojure is hosted on java, and has a lot of ways to interoperate with java artifacts
14:04	Chouser	fyuryu: I don't think you should automatically rule out dispatch on meta-data if it makes sense for your situation.
14:05	danlarkin	Lau_of_DK: how about this: (filter #(every? (fn [coll] (every? prime? coll)) %) lst)
14:06	danlarkin	Lau_of_DK: it's a naive algorithm, though, I admit
14:06	Lau_of_DK	naive?
14:07	danlarkin	Lau_of_DK: inefficient
14:07	Chouser	looks ok to me.
14:07	Chouser	I think "every?" will bail as soon as it gets a false.
14:08	Chouser	indeed it does.
14:08	Lau_of_DK	user=> lst
14:08	Lau_of_DK	((2 3 5 7) (11 17 41 8) (2 4 6 8))
14:08	Lau_of_DK	user=> (filter #(every? (fn [coll] (every? prime? coll)) %) lst)
14:09	Lau_of_DK	Then throws illegal argument exception
14:09	Chouser	you'd want "prime?" to remember it's conclusions (memoize)
14:09	Lau_of_DK	How do I do that Chouser ?
14:09	danlarkin	Lau_of_DK: store it in a hash
14:09	Chouser	clojure.contrib.memoize
14:10	Lau_of_DK	k thanks - any insights into why the filter breaks on that list of lists
14:10	danlarkin	Lau_of_DK: can you paste your prime? function so I can test?
14:11	Lau_of_DK	http://clojure-euler.wikispaces.com/The+Optimal+Toolkit
14:15	wwmorgan_	Lau_of_DK: the first and second lists that you posted have different levels of nesting
14:15	Lau_of_DK	hang on
14:15	Lau_of_DK	the first is the correct, I made the 2.nd by hand
14:16	Lau_of_DK	(defn euler-49
14:16	Lau_of_DK	[]
14:16	Lau_of_DK	(filter #(every? (fn [coll] (every? prime? coll)) %)
14:16	Lau_of_DK	(loop [ n 1000 result [] ]
14:16	Lau_of_DK	(if (< n (- 9999 3330))
14:16	Lau_of_DK	(recur (inc n) (conj result (partition 3 3330 (range n 9999))))
14:16	Lau_of_DK	result))))
14:16	Lau_of_DK	returns "nil"
14:16	Lau_of_DK	That doesnt seem very likely ?
14:20	Lau_of_DK	If I remove the filter and go through the sequence, I can see that partition is making mistakes
14:21	Lau_of_DK	Its not putting 3330 between the offsets...
14:21	Lau_of_DK	oh wait
14:21	Lau_of_DK	Yes it is, I thought it to be the offset between each item, not each list, my bad
14:21	Lau_of_DK	I'll rework it
14:25	Lau_of_DK	Ok, I got everything working now, thanks alot for the input everybody
14:27	danlarkin	Lau_of_DK: how did you end up using filter?
14:27	Lau_of_DK	changed the nesting away from partition, so (filter #(every? prime? %) ...) works
14:28	Lau_of_DK	But you taught me a new thing :)
14:32	danlarkin	Lau_of_DK: cool!
14:34	tWip	a project euler wiki? that makes me sad
14:34	Lau_of_DK	tWip, why ?
14:34	tWip	I find that the most fun part of it trying to solve things yourself
14:34	gnuvince	People will just get the solution pre-made instead of researching it.
14:34	gnuvince	Yeah
14:34	Lau_of_DK	hehe
14:35	fogus	That doesn't stop you from figuring these solutions yourself
14:35	Lau_of_DK	Gentlemen, you dont have to follow those solution (some of them are not very bright)
14:35	gnuvince	It's absolutely infuriating at times, but so nice when you finally get a solution working in less that 18 hours.
14:35	Lau_of_DK	Its meant as an inspiration to use Clojure in different ways, especially good for newbies
14:35	tWip	agreed
14:35	tWip	with what gnuvince said, that is
14:35	Lau_of_DK	No later than today, I pointed a first-timer in Clojure to the wiki, which gave him an easy start
14:40	fyuryu	Chouser: I'm considering it but something in me whispers "don't do it!"
14:42	Chouser	fyuryu: I by no means feel I have a complete sense of when to use metadata, but one thing to hang onto is the concept of equality.
14:43	arbscht	gnuvince: it's also fun to improve upon other solutions, or find ones better than yours
14:43	Chouser	If a particular piece of data for an object can be different but you would still want them to be equal, then it must be metadata.
15:14	Lau_of_DK	Now that the filter works, I get an output like ((1234 4321 1234) (2345 5432 2345))
15:15	Lau_of_DK	I've made a routine that checks if every number is a permutation of 2 others, so
15:15	Lau_of_DK	(permutation? 1234 4321 3214)
15:15	Lau_of_DK	true
15:15	Lau_of_DK	(permutation? 1234 3456 3646)
15:15	Lau_of_DK	false
15:15	Lau_of_DK	How do I filter for permutations?
15:16	wwmorgan_	(filter (partial apply permutations?) coll-of-colls)
15:18	Lau_of_DK	My goodness
15:18	danlarkin	wwmorgan_: tricky
15:18	Lau_of_DK	That worked...
15:19	AWizzArd	how can I do (num "123") ==> 123 ?
15:20	Chouser	(Integer. "123")
15:20	wwmorgan_	AWizzArd: is arbitrary precision required?
15:20	Chouser	That's a constructor of the Integer class.
15:21	AWizzArd	wwmorgan_: please show both ways if possible :-)
15:21	wwmorgan_	Lau_of_DK: how are you detecting numeric permutations? There's an awesome fast algorithm for that.
15:22	Lau_of_DK	(defn permutation?
15:22	Lau_of_DK	[x y z]
15:22	Lau_of_DK	(let [test (apply sorted-set (str x y z))]
15:22	Lau_of_DK	(= (count test) (count (str x)))))
15:22	wwmorgan_	AWizzArd: (BigInteger. "12323849728239473") => 12323849728239473
15:23	wwmorgan_	since you're solving the euler problem, I guess it's OK that (permutation? 1 11 111) returns true
15:24	AWizzArd	wwmorgan_: why is it (BigInteger. ) and not (.BigInteger)? Why is it (.hashCode) and not (hashCode.)?
15:24	danlarkin	(ClassName.) is syntax for (new ClassName)
15:25	wwmorgan_	(.method object) or (.field object) is syntax for (. object field) or (. object method)
15:27	Lau_of_DK	wwmorgan_, do you have something better?
15:28	wwmorgan_	I don't know which would be faster, given that (permutations? 1 11 111) => true is acceptable
15:28	Lau_of_DK	If you want that to return false is just a matter of checking (what I assume) that all args are same length
15:30	wwmorgan_	pasting...
15:32	gnuvince	How about (= (sort xs) (sort ys))?
15:34	wwmorgan_	nm on the paste. What you do is allocate an array of the first 10 primes, then, for each number, map each digit to the respective prime and multiply all the digits together. If every number has the same product, by the Fundamental Theorem of Arithmetic, the numbers are permutations, and if they don't, they're not
15:35	wwmorgan_	so not only is it O(n) in the number of digits, you can fall out early without even looking at later numbers
16:02	danlarkin	clojure/partial is totally sweet
16:04	Chouser	seems kinda old-school to me. I usually prefer #()
16:06	Chouser	but take you're pick -- whatever works! :-)
16:06	gnuvince	partial is gonna appeal to the Haskellers
16:06	Lau_of_DK	partial is nasty
16:06	wwmorgan_	(partial even?) takes more characters than #(even? %) but I think it's slightly more readable
16:07	kotarak	#() is more powerfull since you can choose the argument positions.
16:07	gnuvince	wwmorgan_: yeah, but who would use either one? :) (filter even? (range 20))
16:08	wwmorgan_	gnuvince: whoops, you're right. Change my example to (partial = foo) and #(= foo %)
16:08	Lau_of_DK	Anybody here know of a Java func to load an entire website into a string or something like that
16:08	Lau_of_DK	(slurp www.slashdot.org)
16:08	Lau_of_DK	?
16:09	gnuvince	wwmorgan_: fwiw, I'd use the latter, because it's shorter and clearer IMO.
16:09	Chouser	partial might win me over for varargs. (partial + 10) vs. #(apply + 10 %&)
16:10	chmu_	Is there an eager (map) in clojure. I had some trouble with map and I/O.
16:11	Chouser	wrap any lazy thing in (doall ...) to make it eager.
16:11	hoeck	Lau_of_DK: look at http_client.clj in the google groups
16:11	wwmorgan_	chmu_: you may want to look at doseq for I/O as well
16:11	Lau_of_DK	hoeck, thanks
16:11	Lau_of_DK	hoeck, did you have a crack at this? :) http://paste.lisp.org/display/68934
16:12	chmu_	thanks
16:19	devinus	can you use dashes in fn names?
16:19	Chouser	yes
16:19	gnuvince	devinus: yes.
16:20	gnuvince	devinus: dashes are the standard way to separate words in an identifier in Lisp languages.
16:22	devinus	can you use underscores and Capital letters
16:22	devinus	or even other identifiers, since, really, only parens are needed
16:23	devinus	like (look@something ...)
16:23	devinus	(compute$amt ...)
16:23	devinus	(%ofsomething ...)
16:23	Chouser	you can use underscores and capitals, but if you're doing so for any reason other than interacting with Java, you'll have to put up with people calling your code ugly. :-)
16:23	devinus	(pinch&poke ...) ?
16:23	gnuvince	devinus: I don't know the complete list, but underscore and capitals are definitely permitted, slashes are OK
16:24	devinus	ok
16:24	Chouser	aren't slashes reserved for namespace separation?
16:24	gnuvince	Yes for ampersands.
16:24	gnuvince	Oh right.
16:24	gnuvince	Sorry
16:24	Chouser	question marks are frequently used at the end of a function name to indicate it returns boolean
16:25	Chouser	! at the end suggests it mutates something
16:25	gnuvince	ok
16:25	gnuvince	I got the list
16:25	devinus	i know set!
16:25	gnuvince	alphanumeric, *, +, !, -, _, ?
16:25	devinus	i'm going to have to manually check for everything else
16:25	Chouser	gnuvince: nice, thanks!
16:26	gnuvince	http://clojure.org/reader
16:26	gnuvince	Under "Symbols"
16:28	devinus	does clojure work under java 7?
16:31	hoeck	Lau_of_DK: ahh, i see, euler number 50, i have already a primfac function at hands from my early clojure hackings
16:32	hoeck	Lau_of_DK: but that has to wait until tomorrow, need some sleep
16:32	Lau_of_DK	Okay :) Sleep tight
16:35	devinus	Ok, so you can use these symbols: ! # $ & * . = + ?
16:36	devinus	oh and :
16:37	devinus	and \|
16:37	devinus	You cannot use these symbols in a fn: ~ ` @ % / \ < > [ ] { } ( )
16:37	devinus	and here's a really curious one
16:37	devinus	you can define some var with a period in it
16:37	devinus	(def some.var 3)
16:37	devinus	but when you try to access it you cannot
16:38	Chouser	dots are reserved for java interop when you try to access them
16:38	Chouser	would be nice to get a warning when you try to def it, I suppose.
16:39	wwmorgan_	(var-get (var some.var))
16:39	Chouser	ewww
16:39	Chouser	:-)
16:39	wwmorgan_	ya thats a good one
16:40	devinus	it would also be nice to be able to use ~ ` @ % / \ < > { } in variable names
16:40	devinus	especially @
16:40	devinus	~ too would be nice for approximations
16:40	devinus	~area-of-disk
16:40	devinus	is @ used in clojure?
16:41	Chouser	~ and ~@ are used for inserting stuff in back-quote expressions
16:41	Chouser	(usually used when writing macros)
16:41	danlarkin	It'd be nice to name things like str->int
16:43	devinus	mmm indeed
16:43	devinus	i like that
16:43	wwmorgan_	(defn str->int [s] (Integer. s)) (str->int "123") => 123
16:44	danlarkin	oh... so then < and > are legal in identifiers.. that's what I get for opening my mouth before I check.. d'oh
16:45	wwmorgan_	but it looks like > is reserved though, so I think don't do that
16:45	Chouser	wwmorgan_: why do you say that?
16:45	Chouser	-> is just a regular macro in boot.clj
16:45	Chouser	I used xml-> so if that's bad I should change it.
16:46	wwmorgan_	Chouser: I was going off http://clojure.org/reader but you're right
16:47	wwmorgan_	the -> macro makes it clear that > is supported
16:55	Lau_of_DK	I've used xml-> in a larger program without any problems
18:34	AWizzArd	Without trying it in the repl, if you say (def x (agent [10 20 30])) and then (send x map inc), what do you expect, to what will @x evaluate?
18:35	gnuvince_	[11 21 31]?
18:35	AWizzArd	I agree
18:35	Chouser	after you give it sufficient time to execute?
18:35	AWizzArd	yes
18:36	Chouser	(11 21 31)?
18:36	AWizzArd	I think so, yeah
18:36	Chouser	lazy seq
18:36	AWizzArd	now try it please
18:37	Chouser	ah, of course.
18:37	AWizzArd	enlighten me please
18:37	Chouser	the agent gets passed as the first arg
18:38	Chouser	(map @x inc)
18:38	Chouser	AWizzArd: try: (send x #(map inc %))
18:39	AWizzArd	right, thanks
18:57	AWizzArd	The code of (dispatch ...) is not written in Clojure, right? Used by send and send-off for example.
19:05	Chouser	right, dispatch is a method of the Agent class, written in Java.
19:08	AWizzArd	would be interesting to know what happens if there is a blocking agent in a send-off
19:25	lisppaste8	achim annotated #68934 with "..." at http://paste.lisp.org/display/68934#1
20:13	gnuvince_	lukego: Luke Gorrie?
20:20	lukego	howdy
20:21	gnuvince_	Nice to meet you :)
20:21	lukego	hey I've been your neighbour in #lisp for years and years :)
20:22	lukego	I saw the clojure talk at OOPSLA yesterday so thought I'd take it for a test drive :)
20:22	gnuvince_	Nice to see you here.
20:23	drewc	lukego: how was lisp50? (jerk)
20:23	lukego	drewc: overall very good but some low moments. subject of upcoming blog entry :)
20:23	drewc	looking forward to reading it :)
20:24	gnuvince_	lukego: so I guess that means you're no longer in Thailand
20:25	lukego	I'm in LA en route to New Zealand and Australia at the moment, more or less, but still moving around quite a lot at this stage. I could use a year off this travel business but not quite yet :)
20:26	lukego	the error message is a bit unfriendly when swank-clojure-jar-path is set wrong (NoClassDefFoundError). probably obvious to java people but "file not found" wasn't my first thought
20:30	sohail	lukego, I had the same problem :-)
20:30	lukego	what did you do about it? :)
20:31	jao	/whois sohail
20:31	jao
20:31	jao	oop
20:31	jao	s
20:31	gnuvince_	lukego: rhickey said he was working towards making error messages less arcane
20:31	sohail	lukego, I moved the setting around in the file according to the documentation
20:31	sohail	and then stared at the file name for a long time
20:32	sohail	then finally saw that I was off by a directory
20:32	lukego	this isn't really a clojure error message, it's the JVM reporting that it can't find the entry class to clojure (because I had the wrong path to clojure.jar set)
20:32	sohail	ya
20:32	lukego	right, me too
20:32	lukego	I thought you meant you had a solution to the travel problem, not the jvm problem :)
20:33	sohail	ah
20:48	drewc	sohail: that is a good solution
20:48	drewc	wfm too
20:49	sohail	drewc, good work if you can get it :-)
20:50	drewc	sohail: indeed :)
20:51	sohail	drewc, the next step is to stop working
20:51	sohail	that one is proving hard
20:52	drewc	yeah, that one is a little tougher.
20:53	drewc	well, there's a few easy ways, but they are not at all pleasant.
20:53	sohail	or legal
21:30	gnuvince_	I'm trying to solve #4 of Project Euler with Clojure, but I always get a StackOverflowError
21:31	gnuvince_	Could anyone take a quick look?
21:34	Chouser	where is it?
21:34	gnuvince_	Chouser: just trying something with loop/recur first...
21:35	Chouser	ok
21:37	gnuvince_	Ah
21:37	gnuvince_	There we go
21:38	gnuvince_	~paste
21:38	gnuvince_	@pastebin
21:39	gnuvince_	lisppaste8: pastebi
21:39	gnuvince_	lisppaste8: pastebin
21:39	gnuvince_	lisppaste8: paste
21:39	gnuvince_	damn, what's the frigging command?
21:41	lisppaste8	gnuvince pasted "Euler #4: how does that look?" at http://paste.lisp.org/display/68966
21:41	gnuvince_	Chouser: there it is.
21:42	gnuvince_	How does it look?
21:44	drewc	lisppaste8: url?
21:44	lisppaste8	To use the lisppaste bot, visit http://paste.lisp.org/new/clojure and enter your paste.
21:44	drewc	:)
21:54	lisppaste8	sunwukong annotated #68966 with "How about this?" at http://paste.lisp.org/display/68966#1
21:55	gnuvince_	sunwukong: good one
21:56	Chouser	gnuvince_: yeah.
22:04	lukego	hm so my first idea for a closure program is something that's hard to do in a functional language :-) any tips on a simple graph data structure?
22:06	Chouser	hm! a graph built of persistent data structures?
22:06	gnuvince_	lukego: how many people were present during Rich's presentation?
22:06	lukego	need an indirection somewhere
22:07	lukego	well it was a small workshop. I'd estimate 50
22:08	gnuvince_	Not bad
22:09	Chouser	hash with "id" keys, each val is a vector of adjecent node ids?
22:09	Chouser	that would be a directed graph, I suppose.
22:09	lukego	he did very well in telling the audience "This, this, and this have to be removed from Lisp in this day and age. This, this and this have to be added" to an audience that includes Guy Steele, Dick Gabriel, etc :)
22:10	lukego	must be an amazing salesman to have made me install a JVM
22:11	gnuvince_	lukego: you're not the only one :)
22:12	gnuvince_	Although I must admit that it is astonishing what people on the mailing list say they're doing with a language that's only one year old.
22:14	sohail	gnuvince_, what are they saying they are doing?
22:15	gnuvince_	sohail: people using it to build GUIs, web sites, database applications and whatnot.
22:15	sohail	lukego, what did he say has to be added?
22:15	lukego	concurrency primitives, living on a popular virtual machine are what come to mind
22:19	sohail	lukego, did he talk about how he expects people to live without inheritance and other OOP goodies?
22:20	sohail	(I know the multiple-dispatch is very general, which is cool)
22:20	gnuvince_	sohail: which goodies?
22:21	lukego	no, I heard this talk was very much shorter than what's usual. but Im a CLOS'trophobe and always have been anyway
22:22	sohail	gnuvince_, none really!
22:22	gnuvince_	lukego: you can go to clojure.blip.tv and watch the Boston Lisp User Group presentation
22:22	gnuvince_	It's three hours long
22:23	lukego	I'm a bit bummed by lack of mutation for graphs right now :)
22:25	sohail	lukego, do it in Java ;-)
22:25	lukego	gah :)
22:26	danlarkin	lukego: what do you need mutations for? graphs are just representations of data
22:27	danlarkin	or are you talking about the graphing code itself?
22:27	lukego	well I need some kind of an indirection to represent the circularity. names might do nicely
22:27	lukego	I mean graph as in nodes and vertices
22:28	danlarkin	DAG?
22:29	lukego	a circuit, so more like a DG
22:30	lukego	I'm thinking a nice representation is probably a dictionary of named vertices, with edges being represented as symbols (vertex names)
22:31	Chouser	you might find keywords to be a comfortable alternative to symbols
22:31	danlarkin	how about just a map of edges, {:a :b, :b :c, :c :d}
22:37	lukego	it's a circuit so the vertexes need type information, i.e. they need to be able to compute output values from input values (to implement AND, NOT, etc)
22:41	danlarkin	lukego: I don't quite understand, could you give an example?
22:41	lukego	soon :)
22:42	arohner	is there a macro that collects the results from several expressions?
22:42	danlarkin	it's been a while since I took formal automata in university :-D
22:43	arohner	like (accumulate (foo) (bar) (baz)), and then returns the list of return values from the expressions?
22:43	danlarkin	(list (expr1) (expr2)) ?
22:43	arohner	oh, duh
22:43	arohner	thanks
22:43	danlarkin	arohner: :)
23:28	AlephInf	Hello, the clojure.org front page says "Every feature supported by Clojure is supported at runtime." I don't understand what it implies. Isn't it always true? I am a lisp newbie, so may be I missing something.
23:29	arohner	I think that means there is no difference between compile time and run time, like say, C
23:31	AlephInf	So to twist that statement around, is it fair to say that all the clojure features are also supported at "compile time". That means macros can use agents, STMs and all the clojure goodness?
23:33	arohner	yes, sort of
23:33	arohner	macros return code
23:34	arohner	and that code can make calls to agents, STMs etc
23:34	lukego	how do I find out what I can do with strings? is there a "who specializes"? I want to know how to concat them :)
23:35	arohner	also, macros are expanded when the function that uses the macro is eval'd
23:39	AlephInf	arohner: thanks. I guess I'll have to try attacking On Lisp again.
23:40	arohner	yeah, so do I
23:42	danlarkin	lukego: still waiting on your digraph example :D
23:42	lukego	I'm still trying to write it :)
23:43	arohner	lukego: what is 'who specializes'? Is that a CL thing?
23:43	lukego	but here's an example that was prepared earlier: http://mitpress.mit.edu/sicp/full-text/sicp/book/node64.html
23:44	lukego	arohner: yes. it means "give me a list of methods that dispatch on type <x>" e.g. tell me every method that wants a string. (iirc anyway)
23:45	arohner	that sounds pretty cool
23:45	lukego	it's in the family of cross-reference facilities who-calls, who-binds, who-sets, etc
23:45	lukego	`C-c C-w ...' in SLIME :)
23:45	arohner	this is my first exposure to slime, and I'm just happy with C-c C-d C-d
23:46	danlarkin	lukego: are the who-* functions part of SLIME?
23:47	lukego	that I don't know. ideally they're just bindings but in the old days at least there was a lot of hairy stuff in the per-implementation backends
23:50	danlarkin	they're not in ANSI CL, at least
23:53	lukego	a common-ish extension though. cmucl, sbcl, clozurecl at least support them
23:55	danlarkin	yeah it seems neat
23:56	lukego	how do I get a var that I can set! at the repl?
23:56	arohner	lukego: def
23:56	arohner	but you can only set! inside of a binding
23:58	lukego	I want to have something that looks like a "global variable" to the repl and Emacs commands. maybe I'm on the wrong track. can you give a hint?
23:58	lukego	it does not have to be shared with other threads
23:58	arohner	that sounds like you want a var
23:58	lukego	isn't that what I have?
23:59	arohner	yeah
23:59	lukego	(def foo 1) (set! foo 2) worketh not
23:59	arohner	right, your set can only appear inside the "scope" of a (binding)