#clojure – 2008-11-29

2008-11-29

00:22	ryrunfrnf	is there an autiomatic documentation function for clojure?
00:22	ryrunfrnf	or should i wirte one?
00:32	arohner	ryrunfrnf: what do you mean by automatic documentation?
00:33	arohner	the days off are throwing off my schedule
00:33	arohner	I keep anticipating breakfast "tomorrow"
00:34	arohner	sorry, wrong window
00:42	sdfsf	l
01:12	sdfsf	how do i have a string withint a string?
01:12	hiredman	uh
01:12	hiredman	speak sense
01:20	sdfsf	"hhello "you fool" there"
01:22	danlei	(println "hhello \"you fool\" there")
01:22	sdfsf	ah nice
01:26	peter_12	join #django
01:41	ryrunfrnf	(re-seq #"(defn [a-zA-Z0-9-]*[\[][a-zA-Z0-9][\]]" "defn")
01:42	ryrunfrnf	anyone good with res?
01:42	ryrunfrnf	i want to match (defn f [a b c]
02:04	hiredman	clojurebot: brain dump is http://clj.thelastcitadel.com/clojurebot
02:04	clojurebot	You don't have to tell me twice.
03:13	hiredman	clojurebot: where are you?
03:13	clojurebot	http://gist.github.com/27733
11:22	emacsen	Clojure study in DC next week
11:23	rhickey	emacsen: cool - how many people do you expect?
11:23	emacsen	rhickey, I have no idea. I suggested it but I somehow got dropped from the list and found out from friends on other lists that it was happening
11:24	emacsen	somewhere between 4 and 10 maybe?
11:24	emacsen	no idea really
11:29	emacsen	it's a spinoff group from FringeDC but I think we'll attract other people from the Java and Ruby community maybe
12:38	mtrimpe	Does anyone know if there's a way to persist the history for refs?
12:39	mtrimpe	(where history is all the references the ref has had, so kind of like versioning in a sense)
12:41	arohner	mtrimpe: there's no built in support for that yet
12:42	mtrimpe	arohner: Has there been put some thought into preparing clojure for that? (i.e. are there any obvious roadblocks)
12:42	arohner	I'm not aware of any
12:43	mtrimpe	OK, cool. Is there any persistence available already for objects to start with?
12:43	arohner	I think all it's missing is a 'hook' function. It sounds useful, because I'm not aware of a way to see which value of the ref 'won', in a non-racing way
12:45	mtrimpe	Okay good to know ... and just for a reality check ...
12:46	mtrimpe	I'm planning on building a system in Red5 and using clojure as the functional backend to store a versioned history of the important application state and adding a cells like implementation on top of it that builds up the UI, so that you can basically get 'replayable apps' or apps where the interaction is fully versioned.If that's feasible I'd love to put some work into building it ...
12:47	mtrimpe	Would that be do-able in Clojure?
12:48	arohner	I don't know what red5 is, but the rest of it sounds doable
12:50	mtrimpe	Cool! That means I'll have some serious clojure exploring to do in the next couple of months. Red5 is an open-source Java based Flash server b.t.w. .. basically meaning I'll be doing it for Flash.
13:30	duck1123_	If I have a list of numbers, what's the best way to get the list of numbers that are missing?
13:30	duck1123_	ie. (1 2 4 5 6 8 9) returns (3 7)
13:31	duck1123_	I tried using difference, but I'm getting errors and don't know what I'm doing wrong.
13:31	lvijay	is your list of numbers always sorted?
13:31	duck1123_	yes
13:31	lvijay	do you know what the lowest and highest bounds are?
13:31	duck1123_	and distinct, no nulls
13:32	lvijay	for example (1 2 4 5) could return (3 6 7 8 9 10)
13:32	kotarak	(reduce disj (into #{} (range 1 10)) [1 2 4 5 6 8 9]) (not tested)
13:32	duck1123_	if there's an easy way to get the last element of a list
13:32	duck1123_	can easily be made a vector
13:34	rhickey_	(clojure.set/difference (set (range 1 11)) (set [1 2 4 5]))
13:35	lvijay	(first (reverse vector))
13:35	kotarak	(first (rseq vector))
13:36	lvijay	right
13:36	lvijay	reverse is not lazy
13:36	lvijay	kotarak: thanks
13:36	duck1123_	I'm already consuming the whole seq
13:36	duck1123_	to sort it
13:37	lvijay	you don't need to do it twice
13:37	lvijay	rseq is constant time
13:37	lvijay	if you don't want to use rseq
13:37	duck1123_	This is just code to manipulate my data structure into a new format, this won't have to be run again
13:37	lvijay	you can access the last index of the vector
13:38	kotarak	There's also last.
13:38	kotarak	And for a vector peek.
13:38	lvijay	but last is linear time isn't it?
13:38	kotarak	Yes. peek is not.
13:39	lvijay	ok
13:39	Chouser	last is constant time on vectors, in case that wasn't clear.
13:40	lvijay	the documentation needs to make that more clear then
13:40	lvijay	(peek coll) For a list or queue, same as first, for a vector, same as, but much more efficient than, last. If the collection is empty, returns nil.
13:40	Chouser	oh! hm, let me double-check my statement then.
13:41	Chouser	no, I'm completely wrong.
13:42	Chouser	last is linear time regardless of collection type -- it works strictly on seqs
13:46	Chouser	that's good to know. thanks! :-)
14:07	Lau_of_DK	Chouser: enjoyed the holidays? :)
14:14	Chouser	Lau_of_DK: still enjoying them, yes!
14:19	Lau_of_DK	always with the leaves... :)
14:37	rhickey_	big enhancements to gen-class in SVN 1129: http://clojure.org/compilation
14:38	AWizzArd	rhickey_: will that cause changes for your examples in http://clojure.org/compilation ?
14:38	rhickey_	AWizzArd: the examples have been changed there
14:43	AWizzArd	I am just trying to understand how exactly gen-class works. Can you say in one or two sentences what the big enhancements are?
14:45	rhickey_	The big enhancement is that gen-clas can now be called stand-alone, thus one or more named classes can be generated from a single file. These classes can all be implemented in a single namespace if desired. You can now control the mapping to the implementing namespace, whether or not it gets loaded, and the prefix for functions implementing methods
14:45	rhickey_	the small change is that no named class will be created for a ns unless you put at least and empty (:gen-class) directive in ns
14:45	AWizzArd	wow :-)
14:48	Lau_of_DK	Good work rhickey_ :)
14:50	AWizzArd	this is mostly important if someone wants to provide a lib for use in Java?
14:50	Lau_of_DK	rhickey_: consider streaming your desktop and doing a virtual session out of it? :)
14:51	AWizzArd	Lau_of_DK: probably yes, if we pay him a 100mbit upstream connection g
14:51	Lau_of_DK	AWizzArd: All Americans have 5x100Mbit lines forged with pure gold
14:51	AWizzArd	duh!
14:51	Lau_of_DK	...for every pc
14:51	danlarkin	clojurebot: where are you?
14:51	clojurebot	http://gist.github.com/27733
15:02	Chouser	gen-interface got only 4 votes from the 44 responses
15:03	Chouser	I would never presume, though, to suggest anything about how rhickey_ should be spending his time. :-)
15:03	kotarak	Really?
15:04	kotarak	I'm sure I voted for it.
15:04	kotarak	It's a nice complement for gen-class.
15:04	kotarak	considering Java interop
15:05	AWizzArd	This interop with Java is in my opinion the most complex and ugly part about Clojure. I understand that there is no way around it to have something like that, to profit from the rich set of libs in Java.
15:05	rhickey_	Chouser: unfortunately, people will use gen-class rather than gen-interface + proxy, which is the right thing more often than not
15:05	AWizzArd	I just wished that they all were implemented in Clojure, then this level of complexity would simply go away
15:06	AWizzArd	rhickey_: what is often the right thing? a) gen-class or b) gen-interface + proxy?
15:06	rhickey_	AWizzArd: b)
15:06	rhickey_	people generally use named concrete classes too often
15:08	AWizzArd	I don't know Java well enough to understand why this is not so good. Is gen-class more complex in usage?
15:09	lisppaste8	A.Nonymous pasted "user defined exceptions" at http://paste.lisp.org/display/71233
15:09	AWizzArd	I thought Interfaces are just not-yet implemented classes, to allow a cleaner substitution for multiple inheritance
15:11	rhickey_	AWizzArd: an interface is just that, an interaction agreement, it specifies no implementation details, and is thus the right thing for both basing actual implementations and defining connections between components
15:15	AWizzArd	rhickey_: in http://clojure.org/compilation you say: ":init functions (-ctor in this case) are unusual, in that ...". But -ctor is now called -init since you updated that page.
15:16	rhickey_	AWizzArd: fixed - thanks
15:17	AWizzArd	in the java docs about java.util.Iterator I see that this interface also has a remove method. Why don't you have to implement that as well?
15:19	rhickey_	AWizzArd: remove is an optional operation, if you don't support it you need to throw an UnsupportedOperationException, which is what gen-class will generate for an undefined interface method
15:22	AWizzArd	okay, so this means: whenever I see an interface in the javadoc that lists UnsupportedOperation in its "Throws"-list, I can then decide to not implement it. But all other methods that don't list this exception must be implemented. Yes?
15:23	rhickey_	AWizzArd: the JavaDoc says: optional operation
15:24	rhickey_	Tehnically, you only need to implement the methods you know will be called, but then you aren't a proper implementation, under the hood, all the methods are implemented
15:26	AWizzArd	oh okay, so Clojure provides "empty" implementations?
15:26	gnuvince_	rhickey_: does the dash prefix come from the meaning that it's an instance method?
15:26	AWizzArd	or maybe the dash has to do with privacy?
15:26	gnuvince_	AWizzArd: in ObjC, - is used to denote an instance method and + a class method. I think this convention is also present in UML
15:27	kotarak	AWizzArd: defn- is private -foo is method. They are orthogonal.
15:27	rhickey_	gnuvince_: the dash is an arbitrary mechanical way to avoid clashes with Clojure names, else every gen-class involves a name-conflict-resolution session
15:27	AWizzArd	k
15:27	rhickey_	The prefixes are now user-defineable, dash is just the default
15:28	gnuvince_	ok
15:28	rhickey_	so if you generated a bunch of classes in a single file you could give them all unique prefixes
15:28	rhickey_	All subject to macro-fu
15:34	AWizzArd	@Java people: the :constructors argument of gen-class takes a map in which we map the parameter types of our generated class to the ones of the super class. Is this done because in Java a constructor always must call its superclass constructor?
15:35	stuarthalloway	AWizzard: yes
15:36	AWizzArd	so if someone does not do this in Java manually, will javac then a) complain or b) call the constructor under the hood? If b), with what args would that happen then?
15:37	AWizzArd	( b) in Clojure is manually taken care of, because we must provide this. )
15:37	stuarthalloway	AWizzArd: Java does (b) if it can figure out, e.g. a default constructor, or (a) if it can't
15:38	AWizzArd	oki, thx
15:39	stuarthalloway	AWizzArd: "javap -c" is a great way to spelunk around and see what the Java compiler does behind the scenes
15:39	stuarthalloway	...or any other to-bytecode compiler, for that matter
15:40	AWizzArd	I see
15:40	AWizzArd	stuarthalloway: please look into your /query windows
15:57	AWizzArd	would it make more sense to match the position of constructor and superclass constructor in :constructors in gen-class and in the vector that -init returns?
15:58	AWizzArd	Right now it is :constructors {[subclass] [superclass]} and (defn -init [x] [[superclass constructor] [state of this class]])
16:00	rhickey_	AWizzArd: people are used to constructing their superclass before setting up their own state
16:00	rhickey_	the constructors map isn't really related
16:00	AWizzArd	I see
16:32	moreqwertythanu	im the qwertiest!
16:34	Lau_of_DK	hehe
16:47	AWizzArd	rhickey_: again about your http://clojure.org/compilation example at the bottom. You said :state state and later in -hasNext and -next you use it via (.state this). Why is this .state method needed? Wouldn't it be easier to simply have state available in all the methods?
16:49	rhickey_	AWizzArd: state is a field of the object, it is available, via .state
16:49	AWizzArd	so in reality this is the only field of the class that clojure generates. And into that we can put for example a clojure hashmap inside which we have the real fields that we want to use.
16:50	AWizzArd	(in your example :s and :index)
16:51	AWizzArd	But why has it to be this way? Is there any use for "state" itself after having mentioned it in gen-class? Or will it in all cases be only called in combination with this, as in (.state this)?
16:52	rhickey_	AWizzArd: he functions that implement the methods really have no connection to the objects, they are real fns, not methods
16:53	AWizzArd	Hmm, so is it not possible to simply make "state" available in all the methods magically? @state vs @(.state this)
16:54	rhickey_	no, it's an indirection that allows for a lot of flexibility. For instance, you could have a single fn handle methods for multiple classes, a multimethod as a method handler etc.
16:55	AWizzArd	okay, sounds plausible
16:56	Lau_of_DK	Is there being put any serious work into an sql wrapper for Clojure?
16:57	AWizzArd	Lau_of_DK: is the one from contrib not good enough?
16:57	Lau_of_DK	AWizzArd: it seems half-baked, at least last I looked at it
16:58	AWizzArd	Do you have an example of what is missing there? I haven't looked at it in great detail.
16:58	Lau_of_DK	Then take a look, you'll see
16:59	Lau_of_DK	OrOr let me get back to you on that one, I'll check it out myself, was just poking for alternatives
16:59	AWizzArd	Maybe you remember a specific example? Transactions and prepared statements seem to be in there.
17:24	AWizzArd	for (let [{a "ja" b "nein"} {:x 4 "ja" 8}] (println a b)) I expeted that 8 nil will be printed.
17:25	AWizzArd	This is the case. But for (let [{a "ja" b "nein" :or {"nein" "doch"}} {:x 4 "ja" 8}] (println a b)) I expected to see 8 doch. But I still got 8 nil. Why is that?
17:26	Chouser	try :or {b "doch"}
17:27	AWizzArd	Okay, I see
17:28	rhickey_	SVN 1130 adds gen-interface to AOT
17:28	AWizzArd	so fast!
17:29	AWizzArd	How many hours do you sleep per day? ;-)
17:30	rhickey_	sleep?
17:30	Lau_of_DK	haha
17:30	danlarkin	sleep doesn't help cultivate mad scientist hair
17:31	kotarak	http://en.wikipedia.org/wiki/Sleep
17:32	Lau_of_DK	rhickey_: I have a sincere question. Besides the head-knowledge that youve accumulated, the years of experience in various language and denying sleep. How do you cultivate the type of insight that you have into programming? I mean, there a people who have more experience than you in various languages, yet they never produce anything that comes close to Clojure. How do you hone that quality in you?
17:35	rhickey_	Lau_of_DK: that's very flattering but I'm really just a regular programmer
17:36	kotarak	rhickey_: you are more of an engineer: practical solutions for practical problems. Take what's good and improve it. If that means to leave the lisp weenies behind ("iihhh, what's this [] in the syntax"), then so be it if you get a better result.
17:37	kotarak	(Just an example. Nothing agains lisp weenies.)
17:37	kotarak	(Could as well be lock weenies or whatever)
17:37	AWizzArd	I honestly don't understand what some Lispers have against [] and {}
17:38	Lau_of_DK	rhickey_: I wasnt trying to flatter, Im just trying to develop my own abilities. But if you dont see it that way, I cant convince you that youre a genius, but you can report back here once you come to that conlusion, well pick up the topic again :)
17:39	gnuvince_	Lau_of_DK: "just say no"
17:40	Lau_of_DK	gnuvince_: not understood
17:40	gnuvince_	Lau_of_DK: no to extra features of limited use, no to bloat, etc.
17:41	Lau_of_DK	gnuvince_: not related to expanding your mental capacity without the use of drugs
17:41	rhickey_	http://clojure.org/compilation updated with gen-interface usage
17:41	gnuvince_	If there's one thing I learned since I started using Clojure is that a lot of things people have asked for have not gone in, and Rich has usually provided a good, technical reason why instead of just "because I said so!"
17:43	Lau_of_DK	user> (import '(this.doesnt.exist))
17:43	Lau_of_DK	nil
17:43	Lau_of_DK
17:43	Lau_of_DK	Why is this failing silently ?
17:46	hiredman	it is not failing
17:46	hiredman	you are importing nothing from nothing
17:46	hiredman	failure is impossible
17:47	Lau_of_DK	I want a Does Not Exist error, so that I dont get any surprises later
17:47	hiredman	then import something from nothing
17:47	hiredman	(import '(foo.bar baz))
17:48	AWizzArd	is also * allowed in the place of baz?
17:48	kotarak	no
17:48	AWizzArd	I think in Java one can use it.. import java.util.*;
17:49	kotarak	yes. But not in Clojure.
17:49	walters	should avoid it in Java too - an IDE will manage your imports for you
17:49	AWizzArd	is there a good way to import all classes from a package?
17:50	hiredman	sometimes clojure seems like a completely different language than java
17:50	hiredman	:)
17:50	AWizzArd	I am not a java guy and don't know if it makes sense to import everything. I just assume it does, as Java supports this * thingy.
17:51	hiredman	* is just for when you are lazy and sloppy
17:55	Lau_of_DK	clojurebot: * is just for when you are lazy and sloppy
17:55	clojurebot	You don't have to tell me twice.
17:56	kotarak	Clojure is similar: (use 'some.namespace) vs. (use '[some.namespace :only (foo)])
17:58	AWizzArd	is there a way to get a list of all classes of a specific package?
17:59	AWizzArd	In that case one would have a semi easy way to import everything from a package
18:01	notallama	why do you need to import everything?
18:01	hiredman	rhickey_: what do you think about putting something like (show ...) in core?
18:01	notallama	is it because you're using everything?
18:02	AWizzArd	notallama: I don't need it and as I said a few moments before, I don't even know if that makes sense when working with java classes. But if it really makes no sense, why does java then support it?
18:03	Lau_of_DK	AWizzArd: (import '(javax.swing *)) would certainly make a few programs more concise, you quickly use almost all the components anyway
18:04	dudleyf	AWizzArd: It's not that it makes no sense, it's just that it's usually better to be explicit about what you're using
18:04	AWizzArd	So it typically is a source of problems when people import *?
18:06	dudleyf	If you're importing from several different packages, it can get confusing as to where a particular class came from
18:06	dudleyf	But it's more of a style thing, I think
18:07	AWizzArd	Is there something like (.listAllClassesInPackage "javax.swing")?
18:08	walters	nope
18:08	walters	would be nice, but basically class loading is lazy
19:30	moreqwertythanu	anyone can recommend specific EWDs?
19:30	moreqwertythanu	(edsger dijsktars notes)
19:35	hoeck	moreqwertythanu: "Elegance is not a dispensable luxury but a factor that decides between success and failure."
19:37	timjr	I'm trying to understand the odd behavior (read-line) gives me at the slime repl... it doesn't end up reading the next line of input that I type
19:38	timjr	if I hop over to the inferior-lisp buffer and send some input, then eventually one of the lines of input gets picked up by read-line
19:39	timjr	I haven't understood that yet. But I noticed that (. in read) behaves oddly, slime or no slime... I supposed because the readers buffer up some extra stuff, and in is not the same reader as the one the repl uses
20:30	Chouser	rhickey: I'd be interested in hearing, sometime, your rationale for getting rid of the dynamic class generation stuff (gen-and-load-class, gen-and-load-interface)
20:41	heath	Quick question: is (find) supposed to function as a predicate?
20:42	Chouser	it returns nil if the key is not found, so that could be used as false in a boolean context.
20:43	heath	It definitely works, I'm just wondering if it's idiomatic...
20:43	Chouser	can you show how you're using it? If you're just using it as a predicate, you can probably use the map itself instead.
20:45	heath	I have a list of legal characters, and I need to test if an argument is legal by seeing if it's among them
20:46	rhickey	Chouser: the basic problem with dynamic class generation is that classes are static, i.e. they can't be changed and reloaded. Another reason is that most usage of dynamic things in that area, say, add-classpath, are due to laziness, and yield a system that is unnecessarily dynamic as regards static things, with much ensuing classloader grief
20:46	rhickey	proxy is still there, and is ideal in that it doesn't promise any specific classname
20:47	Chouser	rhickey: I like proxy a lot. it is different from gen-class both in its lack of given classname as well as its inability to add methods.
20:47	rhickey	dynamically loaded classes must be loaded from a custom classloader, which creates all kinds of difficulties in certain hosting environments
20:48	heath	Chouser: I can see you're in the middle of a heavy discussion, so no worries about my question :) I'll just profile it
20:48	Chouser	heath: (:a {:a 1 :b 2})
20:48	rhickey	so people dynamically load classes and complain they can't see them from classloaders not related, especially the system loader
20:49	abrooks	rhickey: Perhaps this can be done with proxy but the only way I know to use JNA is gen-and-load-class and gen-and-load-interface.
20:49	heath	Chouser: Thanks!
20:49	rhickey	I also think that adding methods not present in an interface is bad design
20:49	rhickey	generally
20:49	rhickey	people should program to interfaces
20:50	rhickey	I like how gen-interface has worked out and hope people use it + proxy a lot
20:50	rhickey	abrooks: are you saying there's no way to use the new gen-class for JNA?
20:51	abrooks	rhickey: This is quite possibly my horribly shallow Java knowledge showing but I wasn't able (at the time) to get gen-class working for this: http://groups.google.com/group/clojure/browse_thread/thread/77e626c5440bf1a0
20:52	holmak	I have a question regarding agents when you folks have a minute: http://paste2.org/p/108746
20:52	holmak	(await ...) is throwing a "Exception in thread "main" java.lang.Exception: Can't await in agent action (incr-agent.clj:0)"
20:53	holmak	My (poor) understanding of agents is that you await after sending to block until all the sends are applied?
20:56	abrooks	rhickey: I'll look into this later -- it's been a long time since I touched JNA calling and all the proxy / class loading has changed since then. I'll post to the group if I can't get some workable solution with the mechanisms that are already there.
20:56	rhickey	abrooks: I don't see a reason it wouldn't work, but would require AOT compilation
20:56	abrooks	... log time apparently being two months ago... ;-)
20:56	abrooks	^log^long
21:00	holmak	I understand that (await ...) can't be used within an agent action, but why is it throwing an exception in top-level code, there?
21:00	rhickey	Chouser: so my biggest reservation is the potential for abuse - I can see valid dynamic use cases but can't prevent misguided ones, yet have to support them. The code for gen-and-load-class (in the new model) is sitting there
21:03	Chouser	rhickey: hm, ok.
21:04	rhickey	holmak: don't call your agent agent - didn't you get an error about that?
21:04	holmak	I did not -- I didn't know that was bad.
21:04	rhickey	holmak: I got: java.lang.Exception: Name conflict, can't def agent because namespace: user refers to:#'clojure.core/*agent
21:05	lvijay	holmak: your code is fine except for the agent special variable conflict and old dotimes syntax
21:08	holmak	I may actually be using an incredibly outdated build...
21:10	lvijay	rhickey: is there a way to find out which version of clojure you're currently on from, say, the repl?
21:10	Chouser	lvijay: no
21:10	lvijay	ok
21:11	lvijay	any plans to add one?
21:12	Chouser	lvijay: it has been discussed on a couple occasions on the google group, with all sort of problems dug up and few clear paths forward.
21:12	Chouser	perhaps for the official releases beginning with 1.0, but it's hard to say.
21:13	rhickey	svn info
21:13	Chouser	rhickey: that works unless they downloaded an actual release .zip, right?
21:14	rhickey	the releases have dates as names
21:14	lvijay	java and common lisp provide ways to find out the version so my question. what were the problems? a link to the discussion would suffice
21:14	Chouser	is there any indication in the dir unpacked from the .zip?
21:14	lvijay	the zip name has the date
21:15	rhickey	Chouser: no, just that there are that many releases, and the files have dates...
21:15	rhickey	aren't
21:18	holmak	rhickey: I'm definitely not getting an exception from having "(def agent (agent nil))".
21:18	holmak	But doing things the right way works, so, thanks for the help.
21:21	Chouser	lvijay: http://groups.google.com/group/clojure/browse_thread/thread/1ae7eae292765d40/f0843d43ba678d7e and http://groups.google.com/group/clojure/browse_thread/thread/9fa07b00c88280fc/9feb32c95acbaef9
21:21	lisppaste8	rhickey pasted "jnatest via AOT/gen-interface" at http://paste.lisp.org/display/71245
21:22	rhickey	abrooks: that works fine ^^
21:22	lvijay	Chouser: thanks.
21:27	rhickey	abrooks: once: (compile 'clojure.examples.jnatest) ;will run when compiled due to top-level commands
21:27	rhickey	abrooks: from then on: (load "/clojure/examples/jnatest")
21:27	rhickey	runs like a script
21:28	Chouser	it just seems such a shame to require a compilation pass. I suppose someone could make a jna-clojure lib that requires the dynamic classloader and does the class gen, loading, and passing off to jna.
21:29	rhickey	Chouser: I agree for a one-off, but otherwise people build the gen-and-load-class calls into their app and it grows and then they wonder why they can't see the classes everywhere
21:30	rhickey	same thing happens with add-classpath, it has valid use at repl, but...
21:31	rhickey	I like the dynamic capabilities too, I just have to think of appropriate warning labels, but correct usage in these areas requires more Java savvy than a lot of users have at present
21:32	Chouser	ok, I guess I'm finally with you. If the JVM were different such that this kind of dynamic behavior could be fully supported, that would be one thing. But since it is what it is, trying to pretend it can be as dynamic as gen-and-load requires just leads to confusion.
21:32	rhickey	Chouser: it's also so easy to build a single file now that gens a bunch of stuff - wouldn't you just wrap a lib once and treat the wrapper as a lib?
21:34	rhickey	Chouser: that's why I built in the indirections, so the implementations could still be dynamic, and they are very much so
21:38	Chouser	sure. it's about as good as we can get on the JVM right now. The dynamism of clojure functions, namespaces, and even getting it into some class methods is impressive.
21:40	Chouser	I guess requiring occasional recompiles and re-runs of your app in order to add new class definitions or JNA/native-lib wrappers is just a cost of the JVM.
21:41	Chouser	though I suppose you can write up a new file and namespace, and then compile and load it dynamically.
21:50	MarkVolkmann	I want to print all the items in a collection on separate lines. Why doesn't this work? (map println [1 2 3])
21:51	Chouser	it does, except that map is lazy, so you get extra nils mixed in
21:51	Chouser	try: (doseq [x [1 2 3]] (println x))
21:54	MarkVolkmann	Ah, much better. Thanks!
21:54	Chouser	you're welcom
21:55	Chouser	e
22:02	MarkVolkmann	If you accidently output an infinite sequence in a REPL, is there a way to stop it without killing the REPL?
22:02	Chouser	not that I know of.
22:03	Chouser	but you might choose to set print-length in the future to avoid such situations.
22:14	MarkVolkmann	Is there an initialization file that the REPL automatically reads or do I need to modify my script that starts the REPL to specify the file path using --init?
22:15	Chouser	there is user.clj but that happens too early for print-length
22:16	Chouser	I start clojure with ~/.clojurerc.clj on the command line before whatever .clj I'm actually loading.
22:16	MarkVolkmann	Okay. I'll modify my script to do that.
22:18	Chouser	that's where I set print-length and also defn 'show'
22:20	MarkVolkmann	What is defn show?
22:22	Chouser	MarkVolkmann: http://groups.google.com/group/clojure/msg/96ed91f823305f02
22:24	MarkVolkmann	Thanks! I'll give that a try.
22:37	MarkVolkmann	Seems like I'm tripping over things that should be easy.
22:37	MarkVolkmann	I created this lazy sequence ... (def my-seq (iterate inc 0))
22:37	MarkVolkmann	Why doesn't this produce any output?
22:38	MarkVolkmann	(doseq [x (take 5 my-seq)] println x)
22:38	rhickey	MarkVolkmann: (println x)
22:39	MarkVolkmann	Thanks ... and sorry for the noise ... silly mistake.
23:45	timjr	I used proxy to implement an interface that has a few different methods called "read" in it. I only want to override one of the read methods, but it seems as though the proxy class overrides them all. Is that the case? Is there a way to specify which one to override?