#clojure – 2008-12-14

2008-12-14

00:18	gnuvince_	Don't you hate it when you get a NO_SOURCE_FILE:0 error?
00:18	mmcgrana	are you not using repl-ln?
00:18	gnuvince_	no
00:19	mmcgrana	not not using it or not using it? lol
00:19	gnuvince_	Not using it.
00:20	mmcgrana	well just remember that the regular repl doesn't feed line numbers to the compiler. hence an error in code entered in the repl has that message. repl-ln is very nice you should try it
00:23	gnuvince_	k
00:23	mmcgrana	1:3 user=> (max) java.lang.IllegalArgumentException: Wrong number of args passed to: core$max (repl-1:3)
00:24	mmcgrana	just so you can see what the repl line numbering looks like
00:25	gnuvince_	Does that tell where the error occured in the file that was required?
00:27	mmcgrana	if there error was in another file it should show up as such in the regular repl anyways. you might have an error in the declaration getting those resorces. happens to me alot with (ns and all the (:use and (:import stuff etc.
00:27	gnuvince_	bleh
00:27	gnuvince_	=> (fetch-comic (first comics))
00:27	gnuvince_	java.lang.NullPointerException (repl-1:7)
00:28	mmcgrana	try (first comics)
00:28	gnuvince_	1:8 net.gnuvince.comics=> (first comics)
00:28	gnuvince_	{:prefix "", :regex #"http://abstrusegoose.com/strips/.+?\.(?:jpg\|gif\|png)", :url "http://abstrusegoose.com/", :name "Abstruse Goose"}
00:29	mmcgrana	hmm, and line 7 is the line you invoked the call from, so not helpful?
00:29	gnuvince_	The error is somewhere in fetch-comic
00:29	gnuvince_	I'd really love to know which line
00:31	mmcgrana	oic. well im not positive but i think that with clojure it only puts line numbers for the entire fn in the bytecodes. now often you have nested fns with e.g. #(foo %) and (fn [] (foo)) but otherwise i dont think there is anything we can do
00:31	mmcgrana	except look at fetch-comic and think about it deeply
00:31	mmcgrana	):
00:33	gnuvince_	Which is code I don't really care to look at, cause it's a bunch of Java stuff :-/
00:33	gnuvince_	(proxy and stuff like that)
00:34	mmcgrana	http?
00:34	gnuvince_	yeah
00:34	mmcgrana	i've actually been working on an http lib
00:34	gnuvince_	It's more HTML parsing actually.
00:34	mmcgrana	oic. need hpricot port (:
00:34	gnuvince_	something like that
00:35	mmcgrana	its still on my list. i'll have a month off over january to pound out some serious clojure code
00:37	gnuvince_	I dislike Java's handling of namespaces
00:37	gnuvince_	with all that org.bar.whatever business
00:38	zakwilson	Isn't that just a convention?
00:38	gnuvince_	zakwilson: don't you need to declare your namespace name exactly as the directory structure?
00:39	gnuvince_	like net/gnuvince/comics.clj needs to be (ns 'net.gnuvince.comics)?
00:39	zakwilson	I think you do. I didn't understand exactly what you didn't like.
00:39	mmcgrana	right, the convention part is the choice of net.gnuvince.comics
00:40	gnuvince_	That's a part of Clojure I really don't understand well
00:41	zakwilson	I can see the benefit - it means the locations of things will be very predictable.
00:43	gnuvince_	I guess I'll need to dish out the cash to get an early beta of Stu's book.
00:54	Chouser	new chart: http://clojure.googlegroups.com/web/chart.png
00:54	Chouser	diamonds are non-clojure classes
00:54	Chouser	interfaces, actually.
00:56	mmcgrana	Chouser: very nice, thanks
00:56	Chouser	you're welcome!
00:56	Chouser	I'll put the code up somewhere tomorrow. But for now, bed...
06:27	Lau_of_DK	Good afternoon gents
06:27	bOR_	and to you.
09:09	RSchulz	clojurebot: svn?
09:09	clojurebot	svn is https://clojure.svn.sourceforge.net/svnroot/clojure/
09:09	RSchulz	clojurebot: latest?
09:09	clojurebot	latest is 1159
09:09	RSchulz	clojurebot: contrib?
09:09	clojurebot	contrib is http://sourceforge.net/projects/clojure-contrib/
09:09	RSchulz	clojurebot: contrib latest?
09:09	clojurebot	contrib is http://sourceforge.net/projects/clojure-contrib/
09:35	Chouser	RSchulz: http://clojure.googlegroups.com/web/chart.png
09:36	RSchulz	New one?
09:36	Chouser	yep.
09:36	RSchulz	What are diamonds?
09:36	Chouser	non-clojure classes
09:36	Chouser	it it better or too crowded now?
09:37	RSchulz	I strongly prefer being able to fit it on one page, so no, not too crowded. You should post the code somewhere, too.
09:37	RSchulz	Can DOT produce SVG output?
09:37	Chouser	yeah, working on that.
09:38	Chouser	yep
09:38	Chouser	that .png is actually dot->svg->inkscape->png
09:38	RSchulz	Is there something about that route that's preferable to getting PNG directly from dot?
09:39	RSchulz	Anyway, I like it.
09:39	RSchulz	I still think it deserves the caption: "What a tangled web we weave..."
09:39	Chouser	yes, I think the text layout looks better
09:40	RSchulz	Diagmonds are interfaces?
09:40	RSchulz	You're a Linux user?
09:40	Chouser	diamonds are standard Java interfaces. everything in an oval is in clojure.lang
09:41	Chouser	yep
09:41	RSchulz	The Obj / IObj stuff is a recent addition? I don't remember seeing that before.
09:42	RSchulz	This is one of the few times I wish I had a color printer.
09:42	RSchulz	I like the inclusion of the built-in predicates for those types that have them.
09:43	RSchulz	How long have you been doing FP?
10:34	duck1123	Chouser: is it possible to get the SVG version of that chart?
10:52	RSchulz	Chouser: +1 for duck1123's request; Also...
10:53	RSchulz	Did you have to manually alter the DOT's layout in Inkskape?
12:17	replaca	Q: Can the reader read hex constants a la #x1FC in common lisp?
12:26	kotarak	replaca: I think so.
12:26	kotarak	Just x1fc should be fine.
12:27	replaca	ahh, let me try
12:27	kotarak	No.
12:27	rhickey	user=> 0x1cf
12:27	rhickey	463
12:27	kotarak	You need a zero
12:27	kotarak	Ah. right Rich was faster
12:27	replaca	yup, otherwise it's a symbol
12:28	replaca	thanks rich, sorry to bother with uch a mindane Q, but I wasn't seeing it in the doc
12:28	replaca	*uch => such
12:29	replaca	argh typos! still on the first cup of coffee :-)
13:02	RSchulz	Q: Can (declare ...)-ed names be (defn- ...)-ed? That is, will (declare ...) work for private defns?
13:08	Chousuke	RSchulz: I think private defs differ from regular ones only by having the :private metadata key set to true, so I don't see why that wouldn't work
13:09	RSchulz	OK. I figured it should, but wanted to check.
13:09	RSchulz	Many years of C and a few of C++ have made me wary of learning a language through empirical observation...
13:46	RSchulz	Is there a way to get struct keys from a struct basis? (keys (create-struct ...)) fails with "IllegalArgumentException: Don't know how to create ISeq from: Def"
13:56	RSchulz	clojurebot: 1159
13:56	clojurebot	Gabh mo leithsc�al?
13:57	RSchulz	clojurebot: svn 1159
13:57	clojurebot	svn is https://clojure.svn.sourceforge.net/svnroot/clojure/
13:57	RSchulz	clojurebot: 1159?
13:57	clojurebot	Gabh mo leithsc�al?
13:57	mehrheit	svn rev 1159
13:57	clojurebot	svn rev 1159; proxy perf tweaks Note breaking change if you are using the proxy interface other than the proxy macro itself - proxy maps are now maps of (preferably interned) strings to fns, not symbols to fns, and if you construct a proxy manually you must establish initial map with init-proxy
13:59	RSchulz	mehrheit: Thank you!
14:38	Chouser	RSchulz: (.get (first (.getDeclaredFields (class x))) x)
14:38	Chouser	But of course that's not really supported.
14:38	RSchulz	What is it?
14:39	RSchulz	Oh, the struct question.
14:39	Chouser	yeah
14:39	RSchulz	Do you think it's something that should be supported? I'm trying not to have to replicate the set of struct keys in the code.
14:39	RSchulz	To avoid the possibility of them being out-of-sync.
14:40	Chouser	depends on why you need them, I suppose.
14:40	RSchulz	It's something I always like to do. It's sort of like a kind of normalization for source code.
14:40	danm_	Chouser: print-dup doesn't seem to work with PersistentStructMap, is that intended?
14:41	rhickey	danm_: struct maps aren't serializable yet
14:41	danm_	rhickey: yeah, figured as much looking through the code
14:41	danm_	thanks
14:42	Chouser	RSchulz: I agree you don't want to repeat yourself
14:43	rhickey	clojurebot: faq #1
14:43	clojurebot	Excuse me?
14:43	rhickey	clojurebot: FAQ #1
14:43	clojurebot	FAQ #1 is http://groups.google.com/group/clojure/msg/8fc6f0e9a5800e4b
14:44	Chouser	RSchulz: though you could (def sk [:a :b :c]) (def s (apply create-struct sk))
14:44	RSchulz	Yes, I thought of that.
14:44	RSchulz	It's still cleaner to create the struct basis and have that be the locus of all information about that struct.
14:44	Chouser	RSchulz: the question is why your program wants to treat the included keys differently from the others.
14:45	RSchulz	It's the reverse, I want to have separate processing for the onese that are _not_ in the struct basis.
14:46	Chouser	RSchulz: ok, but what and why?
14:46	Chouser	my point is that it's a bit of an implementation detail, at least right now.
14:46	RSchulz	Does it really matter? I'd have explain a lot of what I'm doing.
14:47	RSchulz	It's certainly not an implementation detail to know what keys comprise a struct basis, is it?
14:47	RSchulz	In a dynamic language?
14:47	rhickey	moving to EPL - prefer: http://opensource.org/licenses/eclipse-1.0.php or http://www.eclipse.org/org/documents/epl-v10.html as the license URL, i.e. does opensource.org add any value?
14:49	rsynnott	rhickey: probably doesn't make much difference
14:49	rsynnott	what license is it at the moment?
14:49	rhickey	CPL
14:49	rsynnott	ah
14:50	rsynnott	why're you changing?
14:50	rhickey	EPL is successor to CPL, acceptable to Google Code and others
14:51	rsynnott	ah, right
15:01	Chouser	RSchulz: I didn't make any changes to the graph in inkscape, though perhaps adding a legend would good.
15:04	clojurebot	svn rev 1160; Moved to Eclipse Public License - see epl-v10.html or http://opensource.org/licenses/eclipse-1.0.php
15:06	rhickey	Chouser: getting ready to move to google code - have created clojure and clojure-contrib projects there
15:06	rhickey	Chouser: Do you have a Google Code account?
15:07	rhickey	Also any other contib members here?
15:09	Chouser	rhickey: yep, username chouser
15:09	rhickey	chouser@gmail.com?
15:09	Chouser	yes.
15:20	RSchulz	rhickey: Does this mean you're vacating the SourceForge project?
15:21	rhickey	RSchulz: there are several steps involved - still looking into what it takes to move the code, which is all that is left as SF
15:21	rhickey	at SF
15:21	RSchulz	There are advantages to hosting at Google Code?
15:22	rhickey	RSchulz: hopefully more usable issue tracking and wiki
15:22	RSchulz	Ah. It's true SF's bug tracking and forum interfaces are pretty bad.
15:24	rhickey	right, google group replaces forums, I pay for wikispaces rather than deal with SF's subframing of it, and SF's issue tracking is awful
15:26	RSchulz	Does this entail switching to Git?
15:27	RSchulz	Uh... Not mercurial, either, right? In other words, sticking with Subversion?
16:27	gp	anyoen could link me to monads in clojure?
16:29	Chouser	did you search on the google group? they come up there from time to time.
16:29	gp	on my way
16:30	jcrites	I didn't know Clojure had a monad representation .... gp send me a link if you find something :)
16:30	gp	rhickey: could there be made some sort of optimization or auto-parallellism with macros+monads in clojure?
16:30	rhickey	http://groups.google.com/group/clojure/browse_thread/thread/9581bf66eb01ca56/8b8f03bcd5854164?lnk=gst&q=monads#8b8f03bcd5854164
16:34	Lau_of_DK	Evening gentlement
16:34	Lau_of_DK	-t
16:34	Lau_of_DK	:)
16:35	danm_	hello
16:56	gp	((comp map filter) #(* % %) #(< % 5) [1 2 3 4 5 6 7 8 9])
16:57	gp	wrong number of args, ok but how do i write it then?
16:58	Lau_of_DK	(doc comp)
16:58	clojurebot	Takes a set of functions and returns a fn that is the composition of those fns. The returned fn takes a variable number of args, applies the rightmost of fns to the args, the next fn (right-to-left) to the result, etc.; arglists ([& fs])
16:58	Lau_of_DK	I havent used that function before, bt it says that its return is a function
16:59	Lau_of_DK	So wouldnt it be (map (comp #(* % %) #(< % 5)) [1 2 3 4]) ?
17:02	kotarak	(map #(* % %) (filter #(< % 5) [1 2 3 4]))
17:04	kotarak	((comp #(* % %) #(< % 5)) 2) => (< 2 5) is true => (* true true) => ?
17:10	Chousuke	gp: ((comp (partial map #(* % %)) (partial filter #(< % 5))) [1 2 3 4 5 6 7 8]) works but you'll really want just (map #(* % %) (filter #(< % 5) [1 2 3 4 5 6 7]))
17:13	Chousuke	or at least give the component functions names before composing :)
17:30	alphazero	hi all, have a question regarding http://paste.lisp.org/display/72155
17:31	alphazero	test.Foo.doX() simply does a stack trace. first version seems to be basically to the metal, but the variant that calls a method on the instance later is using reflection. Why is that?
17:48	wipewindows	i successfully send the message but the
17:48	wipewindows	can someone explain to me how do use agents there?
17:48	wipewindows	http://hpaste.org/13078
17:48	wipewindows	i successfully send the message but it doesnt seem to get updated.
18:03	Chouser	alphazero: since locals are immutable, Clojure can apparently infer that your first 'a' will always be a test.Foo
18:03	Chouser	alphazero: but that may not be a valid assumption for (def a ...)
18:04	Chouser	you should be able to type hint, to avoid the reflection though: (def #^test.Foo a (new test.Foo))
18:08	wipewindows	would it be possible to write a macro that tags types to a function?
18:09	wipewindows	using :inline will that inline it as java code or what des that mean?
18:23	Chouser	sure, you can emit metadata-related code from macros
18:24	Chouser	the :inline stuff essentially allows you to create a function that in some cases can expand into inline clojure like a macro does
18:25	Chouser	inline in clojure means inline in the generate java bytecode, which I suppose can allow HotSpot to do better optimization.
18:43	alphazero	Chouser: thanks. let me try that and see.
18:45	alphazero	Chouser: that did it. Thanks.
18:51	RSchulz	Q: If I have a Java Iterator, how can I iterate over the values it yields?
18:52	RSchulz	user=> (doseq [erec (.iterateErrors psl-all-proc)] (println erec))
18:52	RSchulz	java.lang.IllegalArgumentException: Don't know how to create ISeq from: Itr
18:52	danm_	RSchulz: iterate?
18:53	RSchulz	See above...
18:53	danm_	mmm, sorry
18:53	RSchulz	Iterator<ErrorRecord> iterateErrors()
18:53	RSchulz	Iterate over recorded ErrorRecords.
18:53	blackdog	try putting a seq round it?
18:53	RSchulz	I did that. Exact same diagnostic from Clojure.
18:55	danm_	yeah, the sequence functions call seq for you afaik
18:56	RSchulz	Also...
18:56	RSchulz	user=> (.iterateErrors psl-all-proc)
18:56	RSchulz	#<Itr java.util.AbstractList$Itr@195dd5b>
18:58	danm_	I guess only collections are seq-able
18:58	RSchulz	OK. Flipping it around, what _can_ we do with Java Iterator instances?
18:59	danm_	well, anything you can do in java ;)
18:59	hiredman	there is a function that makes seqs out of iterators
18:59	hiredman	(doc iterator-seq)
18:59	clojurebot	Returns a seq on a java.util.Iterator. Note that most collections providing iterators implement Iterable and thus support seq directly.; arglists ([iter])
18:59	danm_	cool
18:59	RSchulz	Yeah. I just found that.
19:00	RSchulz	So anything Iterable is directly useable as a seq but not a naked Iterator?
19:00	RSchulz	I once asked on the Advanced-Java list why Iterators weren't themselves Iterable.
19:00	hiredman	thats how it reads to me
19:00	RSchulz	But it's moot, of course. They are what they are. I wrote my own IterableIterator class to wrap aribtrary iterators and make them Iterable.
19:01	hiredman	heh
19:01	RSchulz	This particular class's iterator-generating function must have pre-dated the inception of that class.
19:01	hiredman	cute
19:02	RSchulz	God, I love writing my own software. Got a problem with your API? Enhance it!
19:02	Chousuke	I guess an iterator itself is not iterable... but still, it sounds a bit weird
19:03	RSchulz	Chousuke: It definitely is not.
19:04	RSchulz	And just like that, problem solved!
19:04	Chousuke	looks like the iterator interface only specifies the "iterator" function... could be confusing to have iterators return themselves I suppose :/
19:07	rhickey	(doc iterator-seq)
19:07	clojurebot	Returns a seq on a java.util.Iterator. Note that most collections providing iterators implement Iterable and thus support seq directly.; arglists ([iter])
19:10	slangan	octave has a c++ api, does that mean i have to write c++ -> java -> clojure?
19:15	RSchulz	You don't _have to_ do anything, of course.
19:15	rhickey	https://jna.dev.java.net/
19:16	rhickey	People have done JNA directly from Clojure
19:27	aperotte	hello all, I've posted about this before, but I've been trying for a little while and I for some reason really can't get the new gen-class to work well, was wondering if someone could help me out
19:27	aperotte	More specifically I don't really understand how exposes works
19:29	aperotte	I am exposing an ancestral protected member, but after compiling, I can only call the public getter from the instance (not from the class) and also it returns nil instead of the thing I was expecting it to get
19:33	rhickey	aperotte: can you paste something?
19:34	RSchulz	Is it possible to call void (-returning) methods of Java classes?
19:34	aperotte	rhickey: sure, give me a second
19:37	phf	is it possible to extract source location information from java side?
19:38	rhickey	phf: you can call any Clojure fn from Java
19:39	rhickey	get vars with RT.var("ns","name");
19:39	rhickey	call them with invoke()
19:41	whidden	changes in 1160 just the move to eclipse public license?
19:42	rhickey	whidden: yes
19:44	whidden	rhickey: Thanks, saw all the updates and was now sure what was happening :)
19:46	phf	rhickey: sorry, i wasn't at all clear. i meant, is it possible to get the source file location for a java class at run time
19:46	phf	for jumping to source in slime
19:46	phf	apparently not (or only using heuristics anyway)
19:47	rhickey	phf: ah, that's a debugger thing I think
19:48	phf	oh, yeah, that's a good idea
19:50	RSchulz	What determines argument compatibility in calling Java methods? I've got a call that appears to be valid, but is eliciting this:
19:50	RSchulz	java.lang.IllegalArgumentException: No matching method found: printMessage for class rrs.util.ErrorRecord
19:50	RSchulz	The method in question "returns" void.
19:51	rhickey	RSchulz: the return value is irrelevant for matching - is the method overloaded?
19:51	RSchulz	Yes. Two different kinds of output sinks.
19:51	RSchulz	PrintStream and PrintWriter. I'm calling it with out (the default one)
19:52	RSchulz	It's also overrided for different arities.
19:52	rhickey	user=> (supers (class out))
19:52	rhickey	#{java.io.Writer java.io.Closeable java.lang.Object java.lang.Appendable java.io.Flushable}
19:52	rhickey	out is neither of those
19:53	RSchulz	Gagh. Why not?
19:53	RSchulz	Why isn't it System.out?
19:53	rhickey	user=> (class out)
19:53	rhickey	java.io.OutputStreamWriter
19:55	RSchulz	But why is it not simpley equal to java.lang.System/out?
19:57	RSchulz	???
19:58	RSchulz	rhickey: I'd really like to know why out is distinct both in value and type from System.out?
19:59	aperotte	rhickey: paste.lisp.org worked without the channel. Here's my paste, http://paste.lisp.org/display/72170
20:00	rhickey	RSchulz: printing is defined in terms of Writers, which are more useful and avalable than PrintStreams - note how few subclasses of PrintStream there are
20:01	RSchulz	More useful is pretty subjective. I'm fine with it being a PrintWriter, but a mere Writer? Could you make it a PrintWriter?
20:17	rhickey	RSchulz: why don't you bring it up on the group? - I know there were some issues with charsets
20:17	RSchulz	OK. I'll send out a short message on the issue.
20:18	RSchulz	Huh. I just noticed this:
20:18	RSchulz	user=> err
20:18	RSchulz	#<PrintWriter java.io.PrintWriter@6397eb>
20:24	aperotte	rhickey: I need to reboot, I'll brb
20:31	aperotte	rhickey: you have any thoughts on what I might be doing wrong?
20:48	wipewindows	rhickey: was that for me before? could I somehow call a C++ API from Clojure you mean?
20:50	Chouser	wipewindows: http://groups.google.com/group/clojure/browse_thread/thread/77e626c5440bf1a0
20:59	aperotte	rhickey: I have to run, but thanks for offering to help
21:00	RSchulz	aperotte: I had the same problem with paste.lisp.org yesterday. If I selected #clojure as the channel, my paste just disappeared. Only when I did not select a channel (as Rich suggested) was I able to get the paste recorded.
21:01	aperotte	RSchulz: I'm not sure what's going on with it, it doesn't seem to be affecting all of the channels
21:02	RSchulz	I only tried #clojure, though I did that a couple of times. But it was also the case that the whole site appeared to be having serious problems at the time I was trying to use it. One time I got a 502 error.
21:04	rhickey	aperotte: :exposes doesn't handle static fields as static getters/setters, probably should
21:06	aperotte	rhickey: oh ok, thanks! I'm still unsure what was going wrong with the first thing I tried to expose there. Do I need to specify in the methods the return type of the public getter?
21:08	aperotte	rhickey: sadly, I really have to go, thanks again
21:08	rhickey	aperotte: no - it will match the type of the field
21:09	aperotte	rhickey: ok, I'll try again
21:22	phf	starting a jvm with a remote debugger and then recursively connecting from the inside allows for all sorts of introspection capabilities
21:22	phf	for example, to answer my original question
21:22	phf	(.sourcePath (.location (.concreteMethodByName (first (.classesByName vm (.getName (class [1 2 3])))) "count" "()I")))
21:23	phf	returns "clojure/lang/LazilyPersistentVector.java"
21:23	rhickey	phf: fun
21:28	durka	RSchulz: is it not sufficient to do (def pout (PrintWriter. out)) ?
21:29	RSchulz	Flushing?
21:30	durka	hmm?
21:30	RSchulz	What is Clojure trying to tell me with this diagnostic:
21:30	RSchulz	Can't embed object in code, maybe print-dup not defined: clojure.lang.LispReader$Unquote@5d391d
21:32	RSchulz	durka: If you wrap one I/O object around another, you get into trouble when multiple sources do not always flush after writing. And flushing excessively can be a detriment to good I/O performance.
21:32	rhickey	RSchulz: you've got an unquote outside of a syntax-quote?
21:32	durka	i see
21:32	durka	that's a pain
21:34	RSchulz	rhickey: I don't think so, but I'll look more closely.
21:35	RSchulz	Ah. That's it. Yet Another Copy-and-Paste Error.
23:08	yangsx	hi, if my clojure-contrib.jar was updated after slime/swank, how can I force swank to reload it?