#clojure – 2009-11-15

2009-11-15

00:16	cross	hey folks... does anyone know of a built neman cells jar? i'm having all sorts of trouble building it
01:00	aking	ztellman: thanks for penumbra - asteroids and tetris are both neat little example clojure games!
01:06	ztellman	aking: glad to hear it
03:25	scottj	I'm trying to use cljdb and I have ~/src/foo on my classpath and in that dir I have a file bar.clj with (ns bar) and after connecting with slime, loading the file with C-c C-k, and then attaching with jdb, if I try to set a breakpoint it says Deferring breakpoint bar:12. It will be set after the class is loaded. Any ideas?
05:07	Jetien	hi! i'd like to generate some def calls. i thought you could generate some strings for the names and then use something like (def (symbol "foo") bar), but this throws and error.
05:11	_ato	Jetien: the symbol needs to be available at compile time
05:12	_ato	this would be one way: (eval `(def ~(symbol "foo") bar))
05:13	Jetien	thanks! i don't understand how clojure works under the hood yet - when is the code compiled and when is it evaluated?
05:13	_ato	looks like using a macro also works: (defmacro defstr [name value] def ~(symbol name) ~value))
05:13	_ato	(defstr "foo" bar)
05:14	_ato	oops, mispaste, that should be: (defmacro defstr [name value] `(def ~(symbol name) ~value))
05:19	Jetien	what can i read to understand the compilation process of clojure?
05:20	Jetien	or evaluation process
05:22	_ato	sorry... I think I'm full of it :-P actually the problem is just that the def special form doesn't evaluate it's argument
05:22	_ato	otherwise you'd have to write (def 'foo) everywhere
05:22	_ato	and the macro/eval gets around that
05:23	Jetien	ah okay :)
05:24	_ato	so when it sees the (symbol "foo") it sees a list containing a symbol 'symbol and a string and tries to cast that list to a symbol, hence the exception
05:25	Jetien	i see. i was puzzled because (class (symbol "foo")) = clojure.lang.Symbol - so the exception made no sense to me
05:25	_ato	yep
05:25	_ato	,(class '(symbol "foo"))
05:25	clojurebot	clojure.lang.PersistentList
05:34	Jetien	(defstr "foo" 3) works but not (defstr (ex) 3) where (ex) is an expression that yields a string
05:42	Chousuke	Jetien: that's because the macro doesn't evaluate the expression.
05:44	Chousuke	Jetien: you can try printing things inside the macro to see what the parameters are. maybe that'll clarify it :)
05:44	Jetien	okay :)
05:52	_ato	ah, of course. Silly me. You'd have to use eval at some point anyway, I guess
08:21	grammati	When I do this: git clone git://github.com/richhickey/clojure.git clojure
08:21	grammati	I only get the master branch
08:22	grammati	shouldn't I get the newnew branch too?
08:22	grammati	or am I misunderstanding how git works?
08:24	_ato	you're missing understanding how it works :)
08:24	_ato	when you clone git creates a local "master" based on the remote master
08:24	_ato	you can see the remote branche with: git remote show origin
08:25	_ato	if you want to create a "new" local branch try: git checkout origin/new new
08:25	_ato	err
08:25	_ato	git checkout origin/new -b new
08:25	_ato	sorry
08:25	_ato	and it'll track upstream changes
08:26	_ato	the idea is that you can commit stuff to it and it'll automatically be merged with upstream with you pull
08:26	_ato	if you don't want to create a branch, just checkout it
08:26	_ato	ou can just do: git checkout origin/new
08:27	_ato	but you won't be able to commit to it (which maybe what you want anyway)
08:27	grammati	OK, thanks
08:28	grammati	That seems like it should work, except that I don't think git really works on Windows, as far as I can tell
08:28	grammati	As soon as I clone, it tells me that all my java files are locally modified
08:28	grammati	but that's another problem
08:28	Bjering	that is linefeed issue
08:29	Bjering	http://stackoverflow.com/questions/1474686/git-replaced-all-of-my-lf-with-crlf-how-do-i-fix-this
08:29	gerry`	,(deftype Person [name age] [java.lang.Comparator] (.compareTo [o] (compare age (:age o))))
08:29	clojurebot	java.lang.RuntimeException: java.lang.ClassNotFoundException: java.lang.Comparator
08:31	gerry`	,(deftype Person [name age] [java.lang.Comparable] (.compareTo [o] (compare age (:age o))))
08:31	clojurebot	DENIED
08:31	_ato	clojurebot doesn't allow any def forms
08:33	gerry`	,clojure-version
08:33	clojurebot	{:interim true, :major 1, :minor 1, :incremental 0, :qualifier "alpha"}
08:34	gerry`	,(doc clojurebot)
08:34	clojurebot	I don't understand.
08:35	gerry`	clojurebot: help
08:35	clojurebot	http://www.khanacademy.org/
08:35	gerry`	clojurebot: what?
08:35	clojurebot	what is wrong with you
08:36	gerry`	hmm
08:36	Jetien	ha :)
08:37	gerry`	clojurebot: then?
08:37	clojurebot	It's greek to me.
08:39	Jetien	can you kill clojurebot?
08:39	mauritslamers	question: I want something like map, but without having it include nils in the result
08:39	Jetien	,(repeat 6)
08:39	somnium	what's with the hostility towards clojurebot =)
08:39	Jetien	:)
08:39	clojurebot	Execution Timed Out
08:40	somnium	mauritslamers: filter identity
08:40	mauritslamers	I tried for with a :when clause, but for will always walk through every binding
08:41	mauritslamers	somnium: I stopped using filter, because I don't want to filter afterwards
08:41	mauritslamers	because that will force going through the list again and again :)
08:42	mauritslamers	which is not a good idea performance-wise
08:42	somnium	,(for [x (range 50) :when (= 0 (mod x 3))] x)
08:42	clojurebot	(0 3 6 9 12 15 18 21 24 27 30 33 36 39 42 45 48)
08:43	mauritslamers	issue being that I have two lists: one with unique values, the other a list with all data... I want all positions of the unique data in the all data list
08:43	mauritslamers	positions from clojure.contrib.seq-utils works, but that indexes the collection every time
08:44	mauritslamers	I tried something like this: (for [unique uniques-list found-pos (positions #(= unique %) all-data :when (some pred) ] )
08:45	mauritslamers	but that also iterates through every position in found-pos
08:45	mauritslamers	it would be nice if I could prevent the iteration of that found-pos list..
08:46	mauritslamers	let's say that the :when clause should be something like this: :when (> (count found-pos) 1)
08:48	mauritslamers	somnium: any idea how to do this?
08:48	somnium	mauritslamers: I'm not sure I follow
08:49	mauritslamers	ok, I'll try to be a bit more clear :)
08:49	mauritslamers	I have a list with unique values, derived from a list with patterns
08:50	mauritslamers	What I want is a list with positions of every unique value inside the list with patterns
08:50	mauritslamers	I have tried a few things, but they all cause problems in some ways
08:50	somnium	positions = indexes?
08:50	mauritslamers	yep
08:51	grammati	mauritslamers: re. your earlier statement: "I stopped using filter, because I don't want to filter afterwards" - are you clear on how the laziness of map and filter work?
08:51	mauritslamers	the list with indexes should only contain the unique patterns that occur more than once
08:51	mauritslamers	Yes I know what laziness is :)
08:51	mauritslamers	I don't know the exact workings
08:52	somnium	hmm, if you have to keep count of occurrences you probably want to reduce, or maybe loop if necessary
08:52	grammati	OK, it just seemed like maybe you though map would instantiate the whole list, including the values that you will later filer out
08:53	mauritslamers	When I use map for this procedure, I get loads of nils of course
08:53	mauritslamers	on different levels
08:54	mauritslamers	filtering them out, takes at least two extra passes through the entire result
08:54	somnium	also you can use for like [x xs y ys :let [z (* x y)]] :when ...
08:54	mauritslamers	ah...!
08:54	somnium	for can do quite a lot, and when it can't there's reduce and loop
08:54	mauritslamers	was searching for something like that...
08:54	mauritslamers	exactly :)
08:54	mauritslamers	I knew there had to be some kind of way :)
08:55	mauritslamers	Thanks!
08:58	mauritslamers	why do I get an "unsupported binding form :let" ? error
08:59	mauritslamers	old clojure version?
09:00	mauritslamers	or is it not allowed to have both :let and :when?
09:01	somnium	,(for [x (range 10) y (range 10) :let [z (* x y)] :when (= 0 (mod z 3))] z)
09:01	clojurebot	(0 0 0 0 0 0 0 0 0 0 0 3 6 9 0 6 12 18 0 3 6 9 12 15 18 21 24 27 0 12 24 36 0 15 30 45 0 6 12 18 24 30 36 42 48 54 0 21 42 63 0 24 48 72 0 9 18 27 36 45 54 63 72 81)
09:05	mauritslamers	somnium: when I try to have this function evaluated, I get the error #<Exception java.lang.Exception: Unsupported binding form: :let>: http://gist.github.com/235236
09:09	the-kenny	mauritslamers: Your code evaluates here fine (If I define a indexed-function)
09:09	mauritslamers	...
09:09	mauritslamers	weird
09:09	somnium	mauritslamers: what clojure version?
09:09	mauritslamers	1.0 afaik
09:09	mauritslamers	it is the clojure.jar that is part of the textmate bundle
09:13	somnium	hmm, just tried with 1.0.1 and it worked
09:13	somnium	not sure, maybe get latest clojure 1.0 from github? (or 1.1 if you're going to the trouble)
09:13	mauritslamers	there are more strange things: user=> clojure-version
09:13	mauritslamers	java.lang.Exception: Unable to resolve symbol: clojure-version in this context (NO_SOURCE_FILE:0)
09:14	mauritslamers	or the bundle writer in this case :)
09:14	mauritslamers	the bundleit is not part of textmate itself
09:15	mauritslamers	*bundle
09:18	mauritslamers	I'll try the jar from google code
09:18	somnium	netbeans and waterfront are fairly easy to setup alternatives FWIW
09:18	somnium	better from github
09:19	somnium	google code hasn't been used in a while
09:19	mauritslamers	ok, thanks!
09:19	mauritslamers	should I compile my own jars or are there precompiled jars ?
09:19	somnium	github should have some downloads
09:20	somnium	but you just need ant to build them :)
09:21	mauritslamers	afaik ant is normally installed in Mac OSX, so that shouldn't be a real problem :)
09:27	mauritslamers	compiling clojure worked, now trying to compile clojure-contrib, but that returns errors: cannot find Clojure.lang.compile?
09:30	the-kenny	mauritslamers: Have you specified -Dclojure.jar=path-to-clojure to ant?
09:30	mauritslamers	yep
09:30	mauritslamers	the-kenny: otherwise it errors out "not able to find clojure.jar"
09:30	the-kenny	oh hm
09:30	mauritslamers	check_hasclojure:
09:31	mauritslamers	[echo] WARNING: You have not defined a path to clojure.jar so I can't compile files.
09:31	mauritslamers	no -D option specified here..
09:32	somnium	check_hasclojure: passes when you do specify?
09:32	mauritslamers	with -D option: compile_classes:
09:32	mauritslamers	[java] Could not find clojure.lang.Compile. Make sure you have it in your classpath
09:32	mauritslamers	I'll post the entire dump, moment
09:33	mauritslamers	somnium: http://gist.github.com/235256
09:36	mauritslamers	somnium: got it working
09:36	somnium	great, I was clueless :)
09:36	mauritslamers	a path to the file alone is not enough
09:36	mauritslamers	I needed to specify the file
09:36	mauritslamers	so ant -D../clojure/clojure.jar
09:37	mauritslamers	ehh.. ant -Dclojure.jar=../clojure.clojure.jar
09:38	mauritslamers	when only -Dclojure.jar=../clojure is specified, things go wrong... bug in build script?
09:38	somnium	no, clojure.jar is just a variable in the build.xml
09:38	mauritslamers	(typing is not one of my strongest points I believe) ... ant -Dclojure.jar=../clojure/clojure.jar
09:41	somnium	hopefully some alternative build tools are coming around soon, I wouldn't recommend getting into ant if you haven't had to already
09:41	mauritslamers	or just an automatic building tool?
09:42	mauritslamers	anyway, make stuff work again... next issue: the textmate bundle does not behave as expected ... :)
09:42	mauritslamers	Of course I don't expect you to be able to help here much :)
09:43	somnium	can't help with that one, only use emacs and netbeans(for java)
09:43	mauritslamers	np :)
09:43	mauritslamers	you helped me more than enough already, thanks!
09:44	somnium	cheers
09:48	mauritslamers	maybe you could be of some help after all... I tracked part of the problem down to a clojure file supplied inside the bundle... It starts the repl on a server... This file contains a function to create a new thread, but its definition results in an error
09:48	mauritslamers	(defn on-thread [f]
09:48	mauritslamers	(doto (new Thread f) (start)))
09:49	mauritslamers	it says: start: unable to resolve symbol
09:49	somnium	hmm, my guess would be it should be .start
09:54	mauritslamers	that solves one issue, and makes room for the next one: [ss (new ServerSocket port 0 (.getByName InetAddress "localhost"))] => .getByName no matching method found??
09:55	mauritslamers	(import '(java.net ServerSocket Socket SocketException InetAddress) is in the file above
09:55	The-Kennz	mauritslamers: Is .getByName a static method?
09:56	mauritslamers	The-Kennz: no idea to be honest, I am just trying to get my text mate bundle to work again after replacing the clojure.jar and clojure-contrib.jar files
09:56	The-Kennz	mauritslamers: Try (InetAddress/getByName "localhost)
09:57	The-Kennz	s/)/")/
09:57	mauritslamers	solves that issue indeed!
09:58	mauritslamers	it comes back with another one, but I think that can be fixed in the same way
09:58	The-Kennz	mauritslamers: You call "normal" java methods with the .methodName, static methods with Classname/methodName
09:58	somnium	was (.foo Bar) valid for static methods in the early days of clojure?
09:58	The-Kennz	Oh, and you don't need new, you can also write (classname.)
09:59	The-Kennz	somnium: I don't know.
09:59	mauritslamers	The-Kennz: as I said, I am trying to get it working, it is not my code :)
09:59	The-Kennz	Okay
10:00	mauritslamers	I installed it from git://github.com/nullstyle/clojure-tmbundle.git
10:01	The-Kennz	mauritslamers: It looks like nullstyle has stopped development, but other people has continued his work: http://github.com/nullstyle/clojure-tmbundle/network
10:02	mauritslamers	ah, better :)
10:02	mauritslamers	I fixed it by the way, and stuff is working again!
10:04	mauritslamers	The-Kennz: thanks for the idea! Someone else improved it greatly, even adding a updating facility with automated building or something like that... :D
11:02	Drakeson	[using the `new' branch ...] How does one search for interfaces that have a particular method?
11:06	spuz	Has anyone used clojure.contrib.profile?
11:07	spuz	It seems to store the running time of every execution of each of the code blocks as a list which means it can quickly blow the heap
11:08	spuz	It appears there's no reason to store each of the stats that it does so I wonder if there is a reason for it?
12:11	Drakeson	how can I serialize an object to a bytes array?
12:12	Drakeson	for instance, how can I get (1 0 2 0 0 0 3) from [(byte 1) (short 2) (int 3)] ?
12:38	ambient	,(into-array [1 2 3])
12:38	clojurebot	#<Integer[] [Ljava.lang.Integer;@f2a0ef>
13:05	penthief	Hi, is there a better way than: (cons (first my-list) (cons (second my-list) '())) ?
13:10	maravillas	(take 2 my-list)
14:07	G0SUB	Has anyone written a Clojure version of Knuth's man or boy test? http://rosettacode.org/wiki/Man_or_boy_test
14:38	G0SUB	http://rosettacode.org/wiki/Man_or_boy_test#Clojure
14:44	spuz	G0SUB: I can see a Clojure implementation there :)
14:53	patrkris	If I have a ref with a vector in it, and I want to send off an action to an agent every time the first element is added, but not when subsequent elemenets are added, what do I do? Once in a while the list is emptied. It is important that the action sent to the agent sees that the first element has been added (and perhaps elements added in the meantime).
14:57	The-Kennz	patrkris: I'm not sure, but add-watcher could work for refs.
14:57	The-Kennz	a watcher is a function which gets called every time an agent (or ref) gets updated
14:58	The-Kennz	patrkris: http://clojure.org/api#toc66
14:58	The-Kennz	Just add a function that checks if there is only one element in the list.
15:00	patrkris	The-Kennz: thanks for your suggestion - i actually tried using add-watch (not -watchER) but it didn't seem to work. I'll give it a tryk.
15:13	polypus	i would like to write a macro which takes a param vector and a list
15:13	polypus	(f [a b] (a b c d))
15:14	polypus	and returns a function of this form
15:15	polypus	(fn [b d] `(a ~b c ~d))
15:16	polypus	having trouble getting it to work
15:18	hoeck1	(defmacro f [a b] `(fn [b# d#] (~a b# ~c d#)))
15:18	polypus	so that i should be able to write ((f [a] (b a t)) 'z) returning '(b z t)
15:19	polypus	thanks many, i'll give it a go
15:23	hoeck1	polypus: I don't know exactly what you want to achieve, but maybe a function like (#(list 'b % 't) 'z) will do the same?
15:23	polypus	doesn't do it. i should be able to write ((f [a] (b a t)) 'z) and get the list (b z t) back
15:25	polypus	no this is a distillation of a harder problem. i need it to be more general. i really need the behaviour of ((f [a] (b a t)) 'z) -> (b z t)
15:27	polypus	i was hoping to be able to have the macro generated function use syntax quote for performance reasons
15:32	polypus	i just realized that my first definition was wrong, it should have read (f [b d] (a b c d)), thanks for the help
15:33	hoeck1	guess I didn't help that much :)
15:38	polypus	do you think it is even possible to write a macro which builds a syntax unquoted expression and bundles it up in a function?
15:38	somnium	you can emit any kind of symbol with a macro
15:38	somnium	not sure I understand what bundling it up in a function means
15:42	G0SUB	spuz: Yeah, I just wrote it.
15:42	rhickey	protocols - :on is gone
15:52	polypus	bundling up in a function meaning just that from the macro args of a vector [b d] and list (a b c d) the macro will return a function with parameter list [b d] which internally uses syntax quote to return a list where b and d in the original list passed to the macro are replaced by the values passed to the function.
15:52	polypus	so for some macro f
15:52	polypus	(def g (f [b d] (a b c d)))
15:54	polypus	calling function g: (g 4 5) returns the list (a 4 c 5)
15:57	Drakeson	how can I slice an array (or get a sub-array)?
15:57	polypus	so g might look like this internally (fn [b d] `(a ~b c ~d)). but maybe i'm totally barking up the wrong tree
15:59	somnium	polypus: have you looked at definline?
16:00	polypus	no, i will. thx
16:02	rhickey	polypus: there is no point to trying to use syntax-quote here, since you don't know what the args will be. It just expands to calls to quote and list anyway, which is what you'll have to do in your macro
16:04	polypus	ok thx. just a noob trying to wrap my head around this stuff
16:06	rhickey	write a function that when handed '[b d] and '(a b c d) returns '(list (quote a) b (quote c) d), then call it from your macro
16:09	duncanm	i was just thinking, is there a way to 'simulate' the channels in CSP/go-routines using lazy collections/streams?
16:10	duncanm	technomancy: congrats on the elpa upload, i'm downloading now
16:11	piccolino	What got uploaded to elpa?
16:12	duncanm	piccolino: swank-clojure
16:12	piccolino	Like a new version?
16:42	duncanm	la la la
16:52	ordnungswidrig	hmm
17:13	Draggor	How would I go about delivering my clojure app as a single jar?
17:16	mauritslamers	question: I have a let in which I define a binding. The next binding is actually a function which uses that variable inside. When evaluating that function, I get an error. Could anyone tell me why?
17:18	mauritslamers	the error being that it cannot resolve the symbol
17:18	ordnungswidrig	Draggor: do you have dependencies?
17:18	mauritslamers	which is the binding defined first in the let
17:18	ordnungswidrig	mauritslamers: can you paste something to pastebin?
17:18	mauritslamers	ordnungswidrig: of course, thanks!
17:20	mauritslamers	ordnungswidrig: http://gist.github.com/235535
17:20	mauritslamers	the error:<Exception java.lang.Exception: Unable to resolve symbol: indexed-coll in this context>
17:21	Draggor	ordnungswidrig: I do. Actually using compojure and a couple other things
17:21	ordnungswidrig	mauritslamers: is it the let? check the line no. of the excpetion
17:21	ordnungswidrig	,(let [a 1 b (* 2 a)] b)
17:21	clojurebot	2
17:21	mauritslamers	moment, I'll give you the entire function
17:22	ordnungswidrig	Draggor: if you use maven you can use the uberjar plugin. I think it should work with clojure, too
17:22	mauritslamers	ordnungswidrig: please reload the gist
17:24	ordnungswidrig	mauritslamers: When I define a dummy function "indexed" I get no error about indexed-coll. Just about "pattern" not defined.
17:25	Draggor	ordnungswidrig: Don't have maven set up right now, though I did just find this on wikibooks: http://en.wikibooks.org/wiki/Clojure_Programming/Tutorials_and_Tips#Distributing_application_as_self_contained_.jar
17:25	rosejn1	http://sites.google.com/site/rpdillon/creatingexecutablejarswithclojure
17:25	Draggor	rosejn1: Even better, thanks!
17:27	ordnungswidrig	Draggor: you'll have to add you compojure dependencies, of coure. Adding it to the final jar (unzipped) like with clojure.jar should do the trick.
17:27	mauritslamers	ordnungswidrig: strange...
17:27	mauritslamers	ordnungswidrig: the definition of pattern is: (defstruct pattern :pattern :found-at)
17:27	ordnungswidrig	Draggor: http://code.google.com/p/jarjar/ will do the job
17:28	ordnungswidrig	mauritslamers: working from the repl? restart it, perhaps something has been garbled?!
17:28	ordnungswidrig	with the definition of pattern it compiles in my repl
17:28	mauritslamers	I restarted the stuff quite a few times already, no change...
17:29	chouser	rhickey: protocol :on was only for performance? I guess you can use deftype on an interface and still redefine it with roughly the flexibility that extend provides?
17:29	ordnungswidrig	me, bed, now.
17:29	ordnungswidrig	see you!
17:30	ordnungswidrig	mauritslamers: sorry, I'm lost. It's bedtime for me anyways. Good luck!
18:09	AWizzArd	In http://www.assembla.com/wiki/show/clojure/Protocols one of the drawbacks of interfaces is mentioned: they create a isa/instanceof type and a hierarchy. Why are those drawbacks?
18:25	_ato	AWizzArd: I'm uncertain, but from what I've read Rich saying about it, part of the reasoning may just be that hierarchy is an unecessary complication
18:25	AWizzArd	ic
18:27	_ato	oh, and you can define a protocol on anything
18:28	_ato	like for example you can define it on Object or Nil or somebody else's type
18:28	AWizzArd	Do you have an example where this would be useful?
18:28	_ato	that could get weird if it changed hierachy of the type
18:28	_ato	toString() is a simple example
18:29	_ato	what if you wanted to make a to-json function that convrts anything to JSON
18:29	_ato	you'll want to do implmentations for java types like string and what-not
18:29	_ato	and probably default implentation for everything that at least serializes the name of the class
18:31	lisppaste8	Chouser pasted "silly example of extending Integer and String with a protocol" at http://paste.lisp.org/display/90452
18:33	Chousuke	hmm
18:34	Chousuke	I guess you'd need multiprotocols for defining add operations between Strings and Integers :/
18:35	Chousuke	(or rather, integers and Complex numbers :P)
18:35	chouser	right, or regular multimethods
18:36	chouser	I said it was a silly example
18:37	_ato	as someone pointed out on the mailint list, the implementation for an interface could be a multimethod (as a multimethid is just a regular function)
18:38	Chousuke	yeah, but that would negate the performance benefits
18:48	dnolen	one thing I'm confused about deftype and defprotocol. so when defining methods in the type do the method have to exist in a protocol?
18:51	Chousuke	no, the method implementations in deftype are for Java interfaces as far as I know.
18:51	Chousuke	if you want to have your type implement a protocol, you'll need to call extend after the type is created.
18:52	Chousuke	though if the protocol is implemented on top of an interface AND a type implents that interface, there should be no need for the extend :P
18:52	Chousuke	implents... implements.
18:54	dnolen	Chousuke: k so if you're programming in pure Clojure, the general pattern is 1. deftype 2. deprotocol 3. extend ?
18:54	Chousuke	I suppose.
18:55	dnolen	trying to understand what the Clojure bits are, and what the interop bits are, easy to get confused :)
18:56	chouser	protocols can't be on top of interfaces anymore
18:57	chouser	no need apparently as the call-site caching is faster than the :on feature was
18:58	dnolen	chouser: yeah I saw that. So protocols are now always just a list of functions right?
18:58	_ato	ahh, cool, that reduces the confusion
18:58	chouser	dnolen: sounds right
18:59	dnolen	chouser: it also seems with protocols it would be way simpler to create Clojure version of Java libs no? Like go through all the list of methods and automatically generate protocols? or silly?
19:02	Chousuke	hmm.
19:02	_ato	dnolen: does doing that gain you anything over just using (.foo obj)?
19:03	_ato	I guess it could be a way to bridge compatiblity between say different hosts
19:03	_ato	or different library implementations
19:03	dnolen	_ato: yes I was about to reply saying that :)
19:04	_ato	although I'd hazard that most of the time you couldn't just do that automatically, at least for one of the implementations
19:06	dnolen	_ato: true
19:07	the-kenny	Very strange things happen in my code...
19:10	Chousuke	dnolen: I'm thinking that eg. for contrib libraries you could perhaps specify some low-level protocols and write the "meat" of the code on top of those.
19:10	Chousuke	and then every host needs to provide code to implement the protocols
19:12	the-kenny	What can cause (take 24 @my-agent) to fail with a NullPointerException when (take 23 @my-agent) works? (last works too, as does nth)
19:12	Chousuke	but I haven't though much about it at all, so it might be a silly idea, even though it sounds good in my current, rather tired state of mind :P
19:12	the-kenny	This behaviour started after the agent ran a log time (some hours or so)
19:12	the-kenny	s/log/long/
19:12	Chousuke	the-kenny: the seq generating function throws an NPE? :/
19:13	the-kenny	Chousuke: Looks so. I think some very strange things are happening here
19:13	Chousuke	be mindful of laziness and dynamic scope .)
19:14	the-kenny	It worked for over 3 hours now. After that, something breaks.
19:14	Chousuke	:/
19:15	the-kenny	New things gets added to the list in the agent, but I can't dereference it anymore.
19:15	Chousuke	oh, well, I need to get some sleep. Good luck with the bug-hunt :P
19:16	the-kenny	Chousuke: I have to go to bed too ;) Can we continue this tomorrow?
19:22	the-kenny	Nevermind, I'll investigate this tomorrow.. night
19:31	hamza	hey guys, i am trying to locate gen-interface function but it is not in contrib or core?
19:31	rhickey	chouser: right, just use extend on an interface instead of :on. With call-site cache and internal cache not ever faster. Plus i made it so higher-order use just as fast also
19:33	chouser	oh! wow.
19:34	_ato	~def gen-interface
19:34	_ato	hamza: ^
19:34	wooby	has anyone written an interpreter for another language in clojure?
19:37	hamza	_ato: thank you.
19:38	hamza	i am actually looking for gen-and-load-interface function which is not present in source?
19:40	_ato	gen-and-load-interface no longer exist
19:40	hamza	ok, is there a substitute for it?
19:47	_ato	hamza: I don't think so, you're generally supposed to compile things upfront if you want to use gen-class or gen-interface
19:50	hamza	hmm ok thanks.
19:50	hamza	is there a particular reason for removing it? cause to me it just makes things harder.
19:54	dakrone	could someone explain why 'i' isn't being incremented in this? http://paste.lisp.org/display/90457
19:55	_ato	hamza: I don't know, possibly because java doesn't allow classes to be reloaded, so there'd be gotcha situations. the only discussion I could find was this: http://www.mail-archive.com/clojure@googlegroups.com/msg02682.html
19:55	rhickey	hamza: in order consume an interface you need to compile code that knows its name. But it is not generally supportable to expose the names of dynamically created classes, so there are limits to where the name of a generated interface could be seen
19:55	rhickey	also, such classes can only be loaded once per classloader
19:56	hiredman	dakrone: why would it be incremented?
19:56	maravillas	dakrone: inc doesn't modify the original i
19:56	dakrone	oh duh, this is what I get for programming with a fever
19:57	dakrone	immutable, duh
19:57	dakrone	thanks hiredman & maravillas
19:57	hamza	_ato,rhickey thank you both for clarification.
19:57	maravillas	feel better :)
19:57	dakrone	thanks
20:24	hamza	can i type Some.class for a function that expects Some.class as a argument interface is created but i get ClassNotFoundException
20:27	maravillas	try just Some without the ".class"
20:40	lisppaste8	hamza pasted "untitled" at http://paste.lisp.org/display/90458
20:40	hamza	am i missing something? i keep getting class not found although class is present in classes/ folder which is in class path.
20:41	hamza	compile causes java.lang.NoClassDefFoundError: java/lang/Library (jna.clj:13)
20:41	_ato	hamza: have you seen http://github.com/Chouser/clojure-jna ?
20:43	hamza	nope, thanks for pointing..
20:47	lisppaste8	_ato annotated #90458 "works for me" at http://paste.lisp.org/display/90458#1
20:51	hamza	thanks, _ato
20:51	_ato	hamza: oh... wait, just realised what the problem is
20:51	hamza	?
20:52	_ato	you have to specify the full classname in :extends
20:52	_ato	notice the error: java/lang/Library
20:52	_ato	not com/sun/jna/Library
20:52	hamza	ohh ok, got it.
20:52	_ato	I don't know why gen-class/gen-interface don't pickup the imports
20:53	hamza	now it works.. thanks, nice catch.
20:53	_ato	must be something funny about compilation works
21:14	hamza	what does tilde stand for in this context? ~(namespace s)
21:16	cgordon	I'd like to be able to do something like "(compile (first command-line-args))", but I get a class cast exception. How can I convert a String to a symbol?
21:17	chouser	hamza: ~ inside a ` form will unescape
21:18	chouser	,(let [a 5] `(a b c))
21:18	clojurebot	(sandbox/a sandbox/b sandbox/c)
21:18	chouser	,(let [a 5] `(~a b c))
21:18	clojurebot	(5 sandbox/b sandbox/c)
21:18	chouser	cgordon: symbol
21:18	chouser	,(symbol "string")
21:18	clojurebot	string
21:18	chouser	,(type (symbol "string"))
21:18	clojurebot	clojure.lang.Symbol
21:18	cgordon	thanks!
21:20	hamza	chouser is ` like '?
21:20	chouser	hamza: a bit, yes. ` is called syntax-quote
21:21	chouser	the differences are that syntax-quote supports ~ where quote does not
21:21	hamza	ok..
21:21	chouser	also, syntax-quote namespace-qualifies symbols where quote does not
21:21	chouser	['a `a]
21:21	chouser	,['a `a]
21:21	clojurebot	[a sandbox/a]
21:41	Scriptor	hey everyone, after building clojure-contrib, should I be able to see any of the classes for pprint under classes/clojure/contrib ?
21:42	chouser	Scriptor: I have a large number of files in that dir starting with "pprint"
21:42	qed	how does clojure know when all of the threads have gotten a value? like if we're running some concurrent application that does some calculation on several threads, how does clojure know not to return a partial answer that doesn't include all of the threads?
21:42	chouser	qed: are you talking about agents or something else?
21:43	qed	chouser: yes
21:43	qed	err, yes, agents
21:43	Scriptor	chouser: I don't seem to have any
21:43	qed	someone asked me this question earlier and i didnt have an answer
21:43	Scriptor	building gives a few errors but otherwise it says "build successful"
21:45	_ato	Scriptor: did you specify -Dclojure.jar=/path/to/clojure.jar when you compiled?
21:45	qed	clojure.org is down huh?
21:46	Scriptor	yup
21:46	qed	bummer
21:46	qed	i was hopin it'd have the answer to my question :)
21:46	qed	Scriptor: paste the exact line you tiped in when you built clojure-contrib
21:46	chouser	qed: if you want to combine results from multiple agents, it's your own responsibility to make sure all the calculations you want done have been done.
21:46	qed	Scriptor: also make sure you have the most recent versions of both
21:47	qed	chouser: nono, not to combine them or anything
21:47	Scriptor	ant -Dclojure.jar=../clojure_1/clojure.jar
21:47	qed	just how does clojure know when it has all of the answers from the separate threads?
21:47	Scriptor	I should have the recent versions since I only got them yesterday or so, but I'll check
21:48	qed	chouser: maybe that's a silly question -- im not sure
21:48	_ato	qed: it doesn't? what do you mean by "kno when it has all of the answers" ?
21:49	Scriptor	the .clj files are present, but they don't seem to be compiled
21:49	qed	_ato: like if i have some calculation that finds the result of 100^(some random number between 100 and 1000), some of those will take longer than others
21:49	qed	how does clojure know that it shouldnt return when it only has some of those answers
21:49	Scriptor	during compiling I'm also getting a FileNotFoundException for wal__init.class and walk.clj
21:50	Scriptor	*walk__init.class
21:50	rlb	clojure.org seems to be having difficulties...
21:51	rlb	"An unrecoverable error has occurred. The problem has been logged and the Wikispaces staff has been notified."
21:51	qed	rlb: nod
21:51	qed	it's known
21:51	_ato	qed: sorry, I still got don't get what you mean, some of what will take longer? 100^foo is just one operation.. are you parellizing it with agents somehow?
21:51	qed	_ato: yes sorry, i said that earlier
21:52	rlb	Nice, the partial load was good enough for what I needed.
21:52	qed	if we spread this out across mutliple threads and cores, how do we know when we have all the answers for all the calculations
21:52	qed	how do we know not to return an impartial set of results
21:52	chouser	how do you spread it?
21:52	qed	agents
21:52	chouser	each agent only does one operation at a time.
21:53	_ato	qed: do you mean multiple agents? one per core?
21:53	_ato	qed: in that case you have to wait for them to finish using (await agent1 agent2 agent3...)
21:57	qed	_ato: thanks that's the answer i was waiting for
21:57	qed	no pun intended
22:01	qed	clojure.org is back
22:01	qed	FYI
22:02	qed	whoa, someone else in wisc.edu interested in clj :)
22:03	qed	a young one, taboot, must be in the dorms
22:12	hamza	I am trying to use gen-interface to create a function with the signiture (String format, Object... args) how does Object... map to clojure?
22:17	_ato	hamza: when calling Object... is just sugar for an Objec array argument. I'm not sure whether that works when defining an interface method though
22:19	arohner	_ato: I believe it does
22:20	hamza	yeah that's what i thought, i tried [String (to-array Object)] that failed?
22:22	_ato	hmmm
22:22	_ato	,(to-array [])
22:22	clojurebot	#<Object[] [Ljava.lang.Object;@6f403e>
22:22	_ato	maybe "[Ljava.lang.Object"
22:23	hamza	it works in clojure but it does not work in method decleration :methods [[format [String (into-array Object)] void]]
22:24	_ato	,(into-array Object)
22:24	clojurebot	java.lang.IllegalArgumentException: Don't know how to create ISeq from: java.lang.Class
22:24	_ato	,(Class/forName "Object[]")
22:24	clojurebot	java.lang.ClassNotFoundException: Object[]
22:24	_ato	,(Class/forName "[Ljava.lang.Object")
22:24	clojurebot	java.lang.ClassNotFoundException: [Ljava/lang/Object
22:24	_ato	hmm
22:25	_ato	,(class (to-array []))
22:25	clojurebot	[Ljava.lang.Object;
22:26	_ato	,(Class/forName "[Ljava.lang.Object;")
22:26	clojurebot	[Ljava.lang.Object;
22:26	_ato	ah there
22:26	_ato	try that
22:26	_ato	[String (Class/forName "[Ljava.lang.Object;")]
22:26	_ato	or even [String "[Ljava.lang.Object;"] might work
22:28	hamza	:( getting ClassFormatError
22:30	hamza	(make-array)
22:30	_ato	hmm
22:30	_ato	,(make-array)
22:30	clojurebot	java.lang.IllegalArgumentException: Wrong number of args passed to: core$make-array
22:31	_ato	the thing is you don't want an aeeay object you wnt the array type
22:32	Drakeson	How can I run clojure so that I connect to it several times each one getting its own REPL? I have swank if that helps.
22:33	hamza	hmm
22:33	arohner	Drakeson: M-x slime-connect to the running process
22:33	arohner	say no when it asks you if you want to close the old connection
22:35	_ato	hamza: I know there is a way to do it, if you don't specify the types and instead use magic name-mangling
22:35	_ato	_mst told me about it
22:35	_ato	lemme find the link
22:36	hamza	_ato: you mean empty []?
22:36	Drakeson	can I also get REPLs out of emacs?
22:36	_ato	hamza: http://dishevelled.net/Tricky-uses-of-Clojure-gen-class-and-AOT-compilation.html
22:36	_ato	oh wait.. that won't work with gen-interface will it
22:36	_ato	hmmm
22:37	_ato	,(doc asm-type)
22:37	clojurebot	Titim gan éirí ort.
22:39	_ato	,(clojure.asm.Type/getObjectType "java.lang.Integer")
22:39	clojurebot	_ato: Pardon?
22:41	arohner	Drakeson: what do you mean by out of emacs?
22:46	_ato	,(@#'clojure.core/asm-type "Integer")
22:46	clojurebot	#<Type Ljava/lang/Integer;>
22:47	_ato	,(@#'clojure.core/asm-type "[Ljava.lang.Integer;")
22:47	clojurebot	#<Type L[Ljava/lang/Integer;;>
22:47	_ato	:(
22:48	Drakeson	arohner: I want to connect to a running clojure instance. I know how to connect to do this using emacs+slime+swank+clojure. Now, 1. is it possible to connect to the same instance that is serving emacs+slime+swank from a command line (not from emacs). 2. [if 1 fails] Are there any good packages or modules that allow that?
22:49	Drakeson	essentially, I want to get a few "clojure shell"s
22:49	_ato	hamza: looks like you can't do it, might be worth raising it on the mailing list as a bug
22:49	hamza	ok, thanks for the help...
22:51	Drakeson	what idiom should I use to get a run-forever loop?
22:52	_ato	Drakeson: (loop [] ... (recur)) or maybe (while true ...)
22:53	somnium	,((fn [] (recur)))
22:53	clojurebot	Execution Timed Out
22:57	Drakeson	by any chance, do you know how can I create a new emacs frame and run slime-connect in it? (I want to bind all this to a keybinding).
23:03	technomancy	Drakeson: Emacs is the only existing client implemented for the slime protocol, but if you want to access a clojure repl outside of Emacs it's easy to set up a socket repl that works with telnet
23:04	Drakeson	technomancy: I see, thanks.
23:06	Drakeson	I am looking for a quick way to get at a running REPL. Nailgun doesn't work well for me.
23:09	Drakeson	So far, I run a clojure instance which runs swank (outside emacs), then I have bound a window-manager shortcut that runs emacsclient -e "etc." which creates a new emacs frame with a new REPL. I was looking to improve the delay before getting a new REPL ...
23:10	Drakeson	Do you have a better setup that you recommend?
23:14	technomancy	I don't think you'll be able to beat that by much
23:19	Drakeson	btw is there any news on slime/swank over dbus (instead of an non-secure port to which everyone on the same machine can connect)?
23:30	Drakeson	d'oh!
23:30	hamza	can't i use let inside a defmacro?
23:31	_ato	hamza: you can
23:32	hamza	(defmacro afunc[input] `(let [escape ~input] )) i define it like this but i can't call it
23:33	_ato	err.. what's that supposed to do? the body of the for is empty
23:33	somnium	it would error on escape in any case
23:33	_ato	oh and the error is because ` automatically namespace qualifies
23:34	_ato	try [~'escape ~input]
23:34	Drakeson	what do you want to do? that does not do anything other than making `escape' an alias for `input', if input is eval-able.
23:34	hamza	it has no purpose just trying to learn macros. its useless
23:34	defn	how do I use (to-array-2d)?
23:34	defn	(to-array-2d '(1 2 3 4))
23:35	Drakeson	,(to-array-2d [[1 2][3 4]])
23:35	clojurebot	#<Object[][] [[Ljava.lang.Object;@1237512>
23:35	_ato	hamza: try doing: (macroexpand-1 '(afunc ...))
23:35	defn	I see Drakeson
23:35	_ato	it'll show you what's happening
23:36	hamza	ok, thanks.