#clojure – 2008-10-24

2008-10-24

01:40	burkelibbey	I get java.lang.UnsupportedClassVersionError when I do script/run in Compojure (I tried multiple source revisions).
01:40	burkelibbey	Here's the stack trace: http://gist.github.com/19348 . I'm on OS X, and I'm largely clueless about Java. Am I missing something obvious?
01:43	arbscht	burkelibbey: are you running an older jvm than the version you compiled for?
01:45	burkelibbey	oh, quite possible. I'll look into that
01:45	burkelibbey	well... I have java version "1.5.0_16"
01:46	arbscht	what compiler version did you use (or what did it target)?
01:47	burkelibbey	Compojure comes bundled with clojure. I'm not sure
01:47	burkelibbey	I'll try the .jar that I know works on my system
01:48	burkelibbey	oh well there we go. That worked. Thanks :)
01:55	arbscht	was that just the clojure.jar? do the other included jars work?
01:57	burkelibbey	I'm not sure actually. I thought it worked -- no more class version error. Now It's just spinning my processor.
02:04	burkelibbey	hmm, works right away on my linux machine with 1.6.0_07. I probably just have to figure out some way to upgrade java in OS X >_>
02:11	burkelibbey	Ok. Upgrading java fixed my problems. For the logs: http://www.apple.com/support/downloads/javaformacosx105update1.html in OS X.
02:13	arbscht	burkelibbey: out of curiosity, where did you get compojure?
02:14	burkelibbey	arbscht: http://github.com/weavejester/compojure/tree/master
02:16	arbscht	ah, yes, it looks like the clojure.jar classes target java 6
02:16	burkelibbey	Can't hurt to upgrade anyhow
04:57	Pupeno	Hello.
04:57	Pupeno	Anybody knows how to build Enclojure from SVN?
05:03	Pupeno	Hello Lau_of_DK.
05:12	Lau_of_DK	Hello Mr. Pupeno :)
05:24	Pupeno	Lau_of_DK: Everything all-right up north?
05:52	Lau_of_DK	Pupeno, yes sir, it seems that everything is going just fine
05:53	Lau_of_DK	How about the Neutral-land ?
06:32	Lau_of_DK	achim_p, Hi! :)
06:53	achim_p	hi lau!
06:54	arbscht	heh cute, metadata makes it trivial to implement multisets atop sets
06:57	arbscht	http://paste.lisp.org/display/69100
07:01	arbscht	equality semantics are lost though :(
07:03	Lau_of_DK	Looks.... Like Patchworj :)
07:03	Lau_of_DK	k
07:03	achim_p	arbscht: why not just use a map? it would have correct equality
07:04	arbscht	achim_p: yes, I suppose any coll will do
07:05	achim_p	yeah, maps have fast key lookup times, though, should be as fast as a set
07:06	arbscht	achim_p: you mean a map in place of a set?
07:07	achim_p	yes, i'd just use the map you put inside the metadata instead of the set
07:08	arbscht	right
07:09	arbscht	I'm trying to see if the formal definition can be neatly expressed
07:10	achim_p	it would allow for a simple multiset-union: (merge-with + ...)
07:12	arbscht	looks like the way to go
07:13	arbscht	the 'underlying set' is then (set (keys multiset))
07:14	Lau_of_DK	does anyone here have a login to search the logs on this # ?
07:16	achim_p	Lau_of_DK: a login?
07:17	Lau_of_DK	I know that n01se.net monitors the channel, but it requires a login to search
07:18	achim_p	arbscht: yes, but that's probably rarely needed. maps behave much like sets, contains? etc. will work right away for (element->multiplicity)-maps: (contains? {:a 1} :a) => true
07:23	arbscht	achim_p: right
07:23	Lau_of_DK	Should this run? (filter #(every? alphanumeric? %) stream of chars
07:23	Lau_of_DK	When alphanumeric returns true if the charcode is in a certain range
07:23	Lau_of_DK	Shouldnt that filter out alpanumericals?
07:27	Lau_of_DK	achim_p arbscht ? :)
07:28	achim_p	Lau_of_DK: why the "every?"?
07:29	Lau_of_DK	Thats a good question
07:30	Lau_of_DK	I honestly dont know why my logic works that way
07:30	Lau_of_DK	It might be a defect in the brain :)
07:33	achim_p	is stream of chars a sequence of chars? filter decides on a per-item-basis: (filter even? [1 2 3 4])
07:34	rhickey	filter keeps, remove removes
07:34	achim_p	Lau_of_DK: if your stream was a sequence of sequences of chars, you'd need "every?"
07:34	Lau_of_DK	Yes I got that - Thanks :)
07:38	Lau_of_DK	(defn alpha-numeric?
07:39	Lau_of_DK	I dont quite get, why this throws the "Dont know how to create ISeq from Character"
07:39	Lau_of_DK	When you map/filter a stream, % is characters right? and (int \character) is an int ? which I numerically compare to another int
07:39	Lau_of_DK	Its the same with either map or filter
07:40	Lau_of_DK	(filter #(and ((> (int %) (int \a)) (< (int %) (int \Z)))) str))
07:41	Lau_of_DK	(should be <= >= I know)
07:41	rhickey	java.lang.Character.isLetterOrDigit
07:42	rhickey	or whatever
07:42	rhickey	lots of predicates there
07:49	achim_p	Lau_of_DK: how about (.replaceAll "ishjegoiwejf23iu2352j3b5342" "\\d" "") ?
07:50	rhickey	user=> (filter #(Character/isLetterOrDigit %) "abs23-54//:qwer")
07:50	rhickey	(\a \b \s \2 \3 \5 \4 \q \w \e \r)
08:07	Lau_of_DK	Thanks alot Rich :)
09:48	Chouser	I guess I can't (set! print-length 100) in my user.clj?
09:49	rhickey	Chouser: I knew someone would ask that
09:50	Chouser	user.clj seems to be used for various purposes. So far I've only used it to set up my repl with doc/introspection helpers.
09:51	rhickey	It really seems to be a repl setting, not a global one. Perhaps the repl could get defaults from somewhere
09:53	Chouser	~/.clojurereplrc
10:18	Chouser	ok, I moved my personal repl settings to ~/.iclj.clj and created iclj shell script that uses rlwrap, my normal classpath, and include ~/.iclj.clj on the command line to clojure.lang.Repl
10:18	duck1123	I would like to see a setting that wraps the printing of seqs in an implicit (take max-print-sequence ...) so if I accidentally try to eval (constantly 1) I would only see a hundred or so. (with some sort of marker indicating the sequence was trunicated)
10:18	Chouser	this gives me exactly the behavior I want
10:18	Chouser	duck1123: heh.
10:19	Chouser	that's what we're talking about. print-length just went in this morning.
10:19	duck1123	ahh, that was before I logged in this morning
10:20	duck1123	excelent
10:20	Chouser	wasn't mentioned here, just on the google group.
10:20	duck1123	I'm behind on my mail
10:24	j-dot	Chouser: I did essentially the same thing with a REPL-specific script that gets loaded by an iclj shell script. I wouldn't mind seeing something like this supported like user.clj is.
10:25	Chouser	I'm not sure. A distro- or OS-specific script might be just the right place to handle this kind of thing.
10:27	duck1123	http://github.com/dudleyf/clojure-bin loads a ~/.clojure script if it exists
10:27	Chouser	ah, I love. I didn't have to make any changes to clojurescript to support print-length. Re-generate boot.js and it just works.
10:29	Chouser	I'm still trying to figure out the best way to handle passing command-line arguments through to the clojure app.
10:31	j-dot	you mean passing them through a shell script on to clojure?
10:43	Chouser	yeah, with the -- on the java command line
10:44	j-dot	using /bin/sh, appending "$*" to the end of the clojure command works for me
10:46	jdz	j-dot: putting that in double quotes would be wrong i think
10:46	jdz	what i think it means is that all the parameters will be passed as one
10:46	jdz	but i avoid shell scripting like a plague
10:46	j-dot	so, my command is: rlwrap java -cp /path/to/clojure.jar:/path/to/clojure-contrib/src clojure.lang.Repl /path/to/my/repl-specific/initializer/script $*
10:46	Chouser	well, I guess I'm thinking for shebang support. So foo.clj would have #!/bin/clj as its first line, and then running foo.clj --opt1 --opt2 would be like running java clojure.lang.Script foo.clj -- --opt1 --opt2
10:47	j-dot	Yeah, I don't have the quotes
10:49	duck1123	what's the best way to exit from the repl? So far, I've just been hitting C-c, or otherwise killing the connection.
10:50	jdz	C-d?
10:50	Chouser	EOF -- ^D on unix, ^Z on windows
10:50	duck1123	ok
10:57	j-dot	Chouser: in your example, how do you plan on passing the clojure code off to clojure? since "#" isn't a comment char in clojure, foo.clj can't be a straight clojure script.
10:59	jdz	j-dot: #! can be a nice reader macro
11:02	jdz	how does one make a string out of a bunch of characters?
11:03	j-dot	jdz: (apply str '(\a \b \c))
11:07	duck1123	#! should be a reader macro for ;
11:08	duck1123	for those times when you want to start a comment with twice as many characters :)
11:12	fogus	Am I completely braindead, or only mostly-so? http://clojure.pastebin.com/d4f598985
11:18	wwmorgan	is this what you're trying to do? http://clojure.pastebin.com/m75ecfc99
11:20	Chousuke	/usr/bin/clj could just be a wrapper that execs java and clojure. http://clojure.pastebin.com/m75ecfc99
11:20	Chousuke	eh
11:20	Chousuke	I didn't intend to say that.
11:20	fogus	That is it. So 'class' means: dispatch on class?
11:20	wwmorgan	fogus: class is just a function. (class obj) evaluates to the class of obj
11:21	fogus	I see. That makes more sense
11:22	fogus	Thanks for the clarification
11:26	Chouser	j-dot: yeah, I dunno. there is the trick on the wiki.
11:26	j-dot	yeah, I like that trick, but I haven't used it myself
11:27	j-dot	What about clojure.lang.Script treating the first line differently if it starts with a shebang?
11:27	j-dot	i.e., ignoring it
11:28	Chouser	I think that'd make a lot of sense, but I don't have any idea what rhickey would think of it.
11:28	cemerick	rhickey: Shouldn't Float/TYPE => #=java.lang.Float/TYPE, not #=float?
11:29	cemerick	I'm still unsure of my footing with #=, etc
11:31	alvin-x	what's the best way to get a java.util.Map from a clojure.lang.PersistentArrayMap?
11:32	rhickey	cemerick: yeah, looks like they'll need special handling
11:32	rhickey	patch welcome
11:32	cemerick	rhickey: of course, (.getName Float/TYPE) => "float", so perhaps RT.classForName should be the target of the patch?
11:36	rhickey	cemerick: no, Java defines the name of those types, I don't want to mask that
11:36	rhickey	trying to find a #= expression to do this, #=java.lang.Float/TYPE won't work
11:38	Chousuke	alvin-x: just cast it?
11:39	rhickey	user=> (instance? java.util.Map {:a 1})
11:39	rhickey	true
11:40	alvin-x	Exception in thread "main" java.lang.ClassCastException: clojure.lang.PersistentArrayMap incompatible with java.util.Map
11:41	rhickey	alvin-x: what version of Clojure?
11:41	alvin-x	rhickey: clojure_20080916, Java 5, IBM J9
11:42	cemerick	rhickey: array classes are also in a tight spot (#=[Ljava.lang.Object;)
11:43	alvin-x	user=> (instance? java.util.Map {:a 1})
11:43	alvin-x	false
11:43	alvin-x	!
11:43	Chouser	alvin-x: too old. :-(
11:44	alvin-x	Chouser: Clojure, or Java?
11:44	Chouser	alvin-x: clojure maps have implemented java.util.Map since Oct 6
11:44	Chouser	Clojure.
11:44	alvin-x	ok, i'll try from svn.
11:45	Chouser	yep, svn + ant should do it for you.
11:46	cemerick	I think I'm not yet clear on the semantics of #=, but it seems like #=(identity Float/TYPE) would work as a readable Float/TYPE, etc.
12:04	alvin-x	Chouser: thanks for the tip
12:05	Chouser	alvin-x: got it working?
12:05	alvin-x	Chouser: yep; hit other problems regarding RMI, but the problem with Maps is gone.
12:06	Chouser	great.
12:12	cemerick	lisppaste8: url?
12:13	lisppaste8	To use the lisppaste bot, visit http://paste.lisp.org/new/clojure and enter your paste.
12:14	rhickey	cemerick: are you using print/read for serialization now?
12:17	cemerick	rhickey: no, I just ran into this issue while experimenting/learning about #=, etc.
12:17	lisppaste8	cemerick pasted "rhickey: potential print-method patch for primitive classes?" at http://paste.lisp.org/display/69118
12:18	cemerick	rhickey: hope that's what you were aiming for; it seems to work, although I know I don't know the edge cases at work here.
12:19	cemerick	I know you've said that throwing exceptions is a no-no in the core, but I'm not sure what else to do in that case.
12:19	cemerick	it's too bad there's no .getBoxedClass or somesuch on java.lang.Class
12:52	lisppaste8	fogus pasted "fogus" at http://paste.lisp.org/display/69119
12:57	rhickey	cemerick: can just use a map instead of cond, no need for :else
12:59	cemerick	rhickey: for some reason, I had thought you wouldn't like that. That's good though, as there should be a canonical mapping to support emitting primitive class-symbols in macros.
12:59	wwmorgan	fogus: I got a significant speed-up between the first and consequtive runs of (time (mri odd? (range 10000))). Also, remove is now part of the API
13:00	wwmorgan	43ms to 13ms
13:01	fogus	wwmorgan: strange, my second call was 2x slower
13:03	sohail	so if someone wanted to make and distribute some clojure code, do they currently have to ship the source code or can they compile it to class files or some other object files?
13:04	wwmorgan	fogus: also, since your function (and remove) is lazy, you should probably do (time (doall (mri ...)))
13:06	fogus	wwmorgan: Wrapping it with doall was very different. ~40ms vs. 4ms
13:27	dmiles_afk	does clojure work ok in IKVM?
13:32	drewr	dmiles_afk: Check out http://is.gd/4INp
13:33	dmiles_afk	thanks drewr
13:47	Chouser	sohail: currently you ship the clojure source for your app (though it can be bundled in a .jar)
13:49	sohail	Chouser, I guess that it is written in clojure is enough to stop people from trying to tweak it :-)
14:18	lisppaste8	cemerick annotated #69118 with "rhickey: potential print-method patch for primitive and array classes, pt. 2" at http://paste.lisp.org/display/69118#1
14:19	cemerick	that seems to handle primitive and array classes properly
14:27	sohail	can someone verify this for me... clojure has a fixed set of types and you cannot extend the type system by defining compound or aggregate types (you have to use struct maps which are of class StructMap)
14:28	Chouser	a map of vectors or a vector of maps is not a compound nor aggregate type?
14:28	sohail	it is, but one isn't distinguished from another except by comparing each element
14:28	sohail	they aren't tagged automatically, I guess
14:29	Chouser	or by comparing metadata.
14:29	sohail	ah
14:29	Chouser	which as you suggest isn't added automatically
14:29	sohail	doh
14:30	Chouser	I've got half a blog post written on structmaps and multimethods, but I need a better concrete example than what I've got currently.
14:30	sohail	can I see it?
14:30	sohail	where is your blog, btw
14:31	Chouser	It's pretty sparse. Must of my clojure-related writing goes right here, or on the google group.
14:31	Chouser	http://blog.n01se.net/
14:32	Chouser	there's actually a few authors there, but it's the only blog I post to.
14:32	Lau_of_DK	Evening gents
14:33	Chouser	Lau_of_DK, you little devil, you've got me mired in projecteuler again.
14:33	Lau_of_DK	I really wish you'd find another nickname for me, but I'm glad you decided to have some fun with us :)
14:36	Chouser	"fiend" rather than "devil"?
14:36	Lau_of_DK	almost there, add 1x 'r' and Im good :)
15:05	cemerick	using a build from clojure head, I'm seeing stack traces with line numbers that are within ns forms -- is this to be expected?
15:25	Lau_of_DK	Filter is lazy right ?
15:25	wwmorgan	Lau_of_DK: yes
15:25	Lau_of_DK	k
15:26	kotarak	Lau_of_DK: (doc filter) says so, ;)
15:27	wwmorgan	also (do (filter even? (repeat 2)) 1)
16:06	Lau_of_DK	(.. "Hi there" toUpperCase) - Why does this complain about "Hi there" not being recognized as a Symbol when "Hi there".toUpperCase() would fly in Java ( I assume, it would in C# ), and by does (.. (String. "Hi") toUpperCase not work either?
16:06	drewr	(.toUpperCase "Hi there")
16:08	wwmorgan	or (. "Hi there" toUpperCase)
16:09	drewr	That style will be deprecated, but you're right, that's probably what Lau_of_DK was trying to do.
16:09	wwmorgan	oh really? Was that on the group
16:09	wwmorgan	the .method style makes more sense but I didn't know it was going away
16:10	Lau_of_DK	drewr, your example says tht "there" is not a known symbol
16:10	Chousuke	I think it was in the TODO that rhickey pasted a while ago.
16:10	Chousuke	Lau_of_DK: check your typing.
16:10	Chousuke	maybe you forgot a quote?
16:10	drewr	Chousuke: Yep. Doesn't mean it's set in stone, but I think it's likely.
16:11	Chousuke	I suppose it's not that useful
16:11	Lau_of_DK	Chousuke, checked it, its copy/pasted
16:13	drewr	Lau_of_DK: Make sure your IRC client isn't changing the double-quote character.
16:13	drewr	(.toUpperCase "Hi there!")
16:13	drewr	"HI THERE!"
16:13	kotarak	Lau_of_DK: is .. supposed to be a .?
16:14	Lau_of_DK	Is there a command in clojure that will show which rev. Im on ?
16:14	drewr	No, I think rhickey voted that down a while back.
16:14	drewr	Someone might have changed his mind later, but I'm not sure.
16:14	Lau_of_DK	ok
16:14	Lau_of_DK	Its funny
16:14	Lau_of_DK	(.toUpperCase "Hi there!")
16:14	Lau_of_DK	ERROR
16:15	Lau_of_DK	(.toUpperCase "Hi there!")
16:15	Lau_of_DK	"HI THERE!"
16:15	Lau_of_DK	I think my Chimp might be misbehaving
16:15	Lau_of_DK	But thanks for the help everybody
16:27	Chouser	(take 3 (filter #(do (prn :test %) true) (range 10)))
16:27	Chouser	Why does that test 3?
16:29	wwmorgan	because take tests (seq coll) eagerly
16:30	Chouser	take doesn't test anything, does it?
16:30	Chouser	(take 3 (iterate #(do (prn :take %) (inc %)) 0)
16:32	wwmorgan	(seq coll) is always true if coll is an iteration
16:32	Chouser	filter tests, and you're right it seems to do one extra eagerly.
16:33	wwmorgan	yeah you could change the implementation of take
16:35	wwmorgan	actually, I'm not sure about that
16:35	drewr	If I lazy-cat together lazy-cons, will the second lazy-cons ever get called?
16:36	Chouser	I suspect it's the (if (pred (first coll)) ...) in take, because that's outside of any lazy-cons
16:36	drewr	A lazy-cons doesn't be definition have to be infinite, does it?
16:36	drewr	s/be /by /
16:36	Chouser	drewr: right, it could eventually return nil instead of another lazy-cons, and then lazy-cat would go to the next one.
16:36	kotarak	(lazy-cons 5 nil)?
16:37	drewr	kotarak: Good point.
16:38	kotarak	drewr: it just means, the contents don't get evaluated until accessed.
16:38	Chouser	wwmorgan: you're right, it's take's fault.
16:38	Chouser	oh, dangit, messed up my test. ok, still not sure. :-)
16:38	Lau_of_DK	Is there something similar to Contains? that would work on a vector of strings?
16:38	drewr	I'm trying to figure out why lazily pulling queries from a db hangs after the first one.
16:39	Chouser	Lau_of_DK: that's a linear search, which means it'll be slow.
16:39	Chouser	Lau_of_DK: so rhickey has resisted having a builtin, but you can still say (some #{"word"} [...])
16:39	Lau_of_DK	Chouser, enlighten me, you want a hash map then?
16:40	Lau_of_DK	Resistance is futile
16:40	Chouser	yeah, or a hash-set. both would be much faster for looking up a given word.
16:40	Lau_of_DK	ok, and then just use contains?
16:41	Chouser	or just call the set
16:41	Lau_of_DK	how do I automate the calling ?
16:42	Chouser	(def dict #{"one" "two" "three"})
16:42	Chouser	(dict "one") -> true
16:42	Chouser	(dict "five") -> nil
16:43	Lau_of_DK	Alright, while we're at it, I know that Strings have a split function, how do I split every word into a single item, like in C# you could do "Hi there Chouser".Split(" ") = ["Hi" "there" "Chouser"]
16:44	Chouser	(apply hash-set (.split "Hi there Lau"))
16:45	Chouser	sorry: (apply hash-set (.split "Hi there Lau" " "))
16:47	Lau_of_DK	Thanks
16:47	Chouser	wwmorgan: ok, you're definitely correct. It's take.
16:48	Chouser	(first (filter #(do (prn :test %) true) (range 10))) only tests one
16:48	Chouser	but if you use (take 1 ...) it tests 0 and 1
16:48	wwmorgan	right. it checks for logical truth before it decides whether to return a lazy-cons or nil
16:49	Chouser	"take" does? (seq coll) doesn't realize either the "first" or the "rest" parts of a lazy-cons, does it?
16:50	Chouser	oh, it does!
16:50	wwmorgan	it does on a filter, because it has to make sure that at least one remaining element passes the test
16:51	Chouser	man, this is subtle.
16:52	wwmorgan	that's why you didn't see the same behavior on your iterate: an iteration is always logically true
16:52	Lau_of_DK	logically :)
16:53	Lau_of_DK	user=> (containsEnglishWords? "hej med dig, min amerikanske ven er usually meget good")
16:53	Lau_of_DK	("usually" "good")
16:53	Lau_of_DK	sweet, good thinking Chouser :)
17:15	lisppaste8	Chouser pasted "take (fixed)" at http://paste.lisp.org/display/69146
17:16	Chouser	With that, this only tests 0, 1, and 2:
17:16	Chouser	(take 3 (filter #(do (prn :test %) true) (range 10)))
17:19	cemerick	rhickey: did you see this earlier, or no? I've been in and out myself: http://paste.lisp.org/display/69118#1
17:20	rhickey	cemerick: I didn't - looks good, thanks! - could you please post to the group?
17:20	cemerick	rhickey: yeah, I will, thanks
17:21	cemerick	I wasn't really around for any of the conversation about making a print multimethod, etc., but so far, I'm not enamored of the approach so far
17:22	cemerick	(I hate to be one of those people that pops up with opinions long after decisions are made and code is written :-) )
17:23	rhickey	cemerick: what would you propose instead?
17:23	cemerick	It seems like there's a lot of niggly details that will need to be resolved (e.g. classnames of primities and arrays), a lot of reinventing the wheel given that there's a lot of serialization mechanisms for Java.
17:24	Chouser	cemerick: are you talking about multimethod vs. written in Java? Or the new #= format?
17:26	cemerick	I suppose the #= format. There's nothing to say that the existing javabean serialization (for example) couldn't just get dropped into a form that the reader would bring back in transparently. There's less lispy love there, but I worry about what dragons await yet another serialization mechanism.
17:27	cemerick	I'm sure I've not thought about the issues nearly as much as others, so take all this with the requisite pound of salt. :-)
17:27	Chouser	I don't think there was any discussion of the #= format. :-)
17:28	rhickey	cemerick: I looked at JavaBean serialization - it's unconscionably verbose
17:29	cemerick	definitely so, but it works, and has a lot of support behind it so it will "automatically" grow along with new JDK versions, etc
17:30	cemerick	is verbosity an issue, though? How often would we expect serialized objs to be viewed by humans?
17:30	rhickey	um, every time they work at the repl?
17:31	cemerick	there's clearly some benefits to having everything be printed readably all the time, but the repl vs. storage vs. transmission are very different use-cases
17:32	Chouser	the old print format didn't work for storage or transmission of unusual Java objects either, did it?
17:33	rhickey	cemerick: print/read is a strong and valuable Lisp tradition, nothing about it removes other serialization mechanisms
17:33	cemerick	Chouser: no, not at all
17:35	cemerick	rhickey: Sure. I guess I'd just worry about having to keep print-method well-fed.
17:36	cemerick	...in addition to whatever odd corner-cases exist w.r.t. Java idiosyncrasies
17:36	cemerick	This is all monday-morning quarterbacking on my part though, so I think I'll just sit back down. :-)
17:38	rhickey	I think Javabeans serialization might be a good fallback if no other method is defined, the current default has only been marginally useful
17:39	cemerick	rhickey: hrm, having a featureful fallback is a good idea. I suspect Javabean serialization is just a baseline though -- I'm sure there's better options. I brought it up only because I'm familiar with it.
17:43	duck1123	so is anyone here familiar with compojure?
17:43	duck1123	I'm still having troubles getting the compojure repl connected via slime
17:44	cemerick	huh, looks like the google group email gateway has gotten snappier
17:44	lisppaste8	rhickey pasted "XMLEncoder format" at http://paste.lisp.org/display/69149
17:45	rhickey	cemerick: it is text, but another problem is its graph nature
17:45	cemerick	oh, yeah, it can get vile -- but for storage/transmission, it's great as long as it's zipped
17:46	cemerick	I've not thought much about serialization issues -- I'm not aware of the problem(s) with object graphs.
17:49	cemerick	have a good weekend, everyone!
17:51	drewr	In JSwat, I see a Timestamp object, but its value is "#2455."
17:51	drewr	Is that a memory address?
17:51	drewr	Can I only inspect strings?
18:00	islon	hi guys o/
20:31	sohail	is let like let* or like let from CL
20:32	rhickey	sohail: like let*
20:32	sohail	thanks rhickey, I am not very good at navigating the documentation
21:20	RadioApeShot	Question, is there a predicate which detects whether a thing is seq-able?
21:20	drewr	(doc seq?)
21:20	RadioApeShot	seq? detects if a thing _is_ a seq
21:21	drewr	True.
21:21	RadioApeShot	So (seq? [1 2 3]) -> false
21:21	RadioApeShot	Suppose one wanted to write a function which returns the first of a thing if the thing is seq-able, like a vector
21:22	drewr	Idiomatically, you just (when (seq [1 2 3]) ...)
21:22	RadioApeShot	But otherwise returns something else
21:22	RadioApeShot	when
21:22	RadioApeShot	Very clever.
21:22	RadioApeShot	Thanks
21:23	RadioApeShot	But wait
21:24	RadioApeShot	(defn first-or [x y] (when (seq x) (first x) y))
21:24	RadioApeShot	That still will not work
21:24	RadioApeShot	At least it will not if x is, for instance, a symbol
21:25	RadioApeShot	because (seq x) will throw an exception
21:25	drewr	Yes, you need to be fairly certain you're getting some kind of collection.
21:25	RadioApeShot	Is there a collection?
21:25	RadioApeShot	(collection? x)
21:26	RadioApeShot	I am just porting some Scheme code where I use the nth-or idiom a lot.
21:26	drewr	Can you wrap it in a try and deal with the exception?
21:26	RadioApeShot	But I am trying to make this collection independent.
21:26	RadioApeShot	I can do that
21:26	RadioApeShot	It just seems a bit weird to do so.
21:27	drewc	is there an IGNORE-ERRORS in clojure?
21:27	RadioApeShot	Not that I know of.
21:28	drewc	seems like a use-case.. though quite frankly i avoid it in CL and prefer the explicit error handlers.
21:28	drewc	(defn first-or [x y] (when (ignore-errors (seq x)) ...)
21:28	RadioApeShot	Ok
21:28	RadioApeShot	Place is closing
21:28	RadioApeShot	Gotta run
21:28	RadioApeShot	Thanks for the help
21:29	RadioApeShot	I appreciate it
21:30	drewr	(doc coll?)
21:36	drewr	drewc: How are you liking clojure so far?
21:37	drewc	drewr: having a lot of fun so far :)
21:38	drewr	Awesome.
21:38	drewc	drewr: i have not been working with it long enough for any of my grievances to have any real merit.
21:38	drewc	lisp-1 is driving me nuts, but i'm willing to look past it :)
21:39	drewr	Haha.
21:40	drewr	We incited some discussion about that at dinner before lisp50.
21:41	drewc	me, i'm just exited that there is a new lisp actually worth looking at. Rich has put an incredible amount of thought into it, and he has the cojones to go through with it.., i'm suitably impressed.
21:42	drewc	talking
21:42	drewr	:-)
21:46	drewc	I'm getting used to the syntax even .. who'd a thunk it.
21:49	drewr	I find it extremely expressive.
22:00	drewc	what i absolutely _love_ is STM
22:09	rhickey	Nice blog from OOPSLA: http://lispy.wordpress.com/2008/10/25/lisp50-notes-part-vi-the-future-of-lisp/
22:16	danlarkin	the default wordpress template annoys me so much
22:17	danlarkin	because when I increase the font to a readable size then only like 5 words fit on a line