#clojure – 2008-11-01

2008-11-01

00:14	sunwukong	hi
00:16	sunwukong	browsing the closure-contrib files I've noticed that cond-let evaluates the first true test twice
00:17	sunwukong	I've created a patch for it - what's the stadard way to get this into svn?
00:33	danlarkin	sunwukong: http://clojure.org/contributing
00:35	sunwukong	that's nice, but seems an awful lot of work for a 3-line change :)
00:38	lisppaste8	sunwukong pasted "cond-let fix" at http://paste.lisp.org/display/69541
01:35	asbjxrn	Anyone using java debuggers together with slime?
01:36	asbjxrn	Seems to me that slime captures exceptions and prevents the debugger from getting to it?
05:53	AWizzArd	Moin
05:53	kotarak	salut
07:43	Lau_of_DK	Good day, folks
07:43	kotarak	Salut Lau
08:52	Lau_of_DK	rhickey, last I was head you said that AOT would subsume gen-class functions. Firstly, you cant use words like "subsume" with danish people, and second, would you please explain the practical implications of AOT ?
08:52	Lau_of_DK	head = here
08:54	rhickey	http://dictionary.reference.com/browse/subsume
08:55	Lau_of_DK	Yes sir, Im aware of dictionaries. I fail to see how I can prepare my code for the removal of gen-class when Im currently depending on it. So I was hoping for some insight into how AOT will be used in Clojure.
08:58	ReplRat_	AOT?
08:58	rhickey	Lau_of_DK: Don't worry about genclass being removed yet, there's no alternative anyway. I can't say how it will work until I've finished designing it. That won't happen until next week. Fundamentally it will be the same - generated classes will map methods to Clojure vars. All that might change is the syntax and organization, and for the better.
08:58	Lau_of_DK	Alright thanks - That puts me at ease :)
08:58	kotarak	ReplRat_: ahead of time compilation
08:59	kotarak	ReplRat_: compiling clojure to .class files
09:02	pjb3	Go Vote! http://thediscoblog.com/2008/10/19/poll-which-language-is-better-suited-for-jvm-concurrency/
09:03	pjb3	and not for Obama or McCain :)
09:18	vy	rhickey: Do you consider moving documentation pages on clojure.org to a documentation scheme -- e.g. DocBook, LaTeX, etc.?
09:36	Chousuke	maybe restructuredtext, if you don't want to learn a complex markup language. :)
11:34	Drakeson	(def a [1 2 3]) (a 0) -> 1, wouldn't it be nicer if (a 0 3) -> [1 2 3], or maybe (a 0 2) -> [1 3], or maybe (a [0 2 0]) -> [1 3 1] ?
11:36	Drakeson	or maybe (def a [[1 2][3 4]]) (a 0 1) -> 3
11:37	Drakeson	err, 2, that is
11:42	Chouser	(get-in a [0 1]) for the latter case
11:42	Drakeson	but (a 0 1) is not used for anything else.
11:42	Chouser	(map a [0 2]) for the former
11:43	Drakeson	Chouser: well, I am arguing about the builtins, (again).
11:45	Chouser	get-in has neighbors assoc-in and update-in
11:45	Chouser	(assoc-in a [0 1] 99) -> [[1 99] [3 4]]
11:45	Chouser	(update-in a [0 1] #(* 10 %)) -> [[1 20] [3 4]]
11:47	Chouser	Drakeson: I'm not arguing with you, I'm just not sure which of these behaviors is so much mor common than the others that it should become the default when you use a vector as a function.
11:49	Drakeson	for (a 0 1) to mean (get-in a [0 1]) sounds natural when (a 0) gives you (get-in a [0])
11:50	Drakeson	don't you agree?
11:51	Drakeson	well, at least, do you agree that (a 0 1) should have a meaning?
11:52	Chouser	I think it's better to have no meaning than the "wrong" one. Once it has a meaning, it'll be very difficult to change it later.
11:53	Chouser	having said that, get-in would seem reasonable. ...except I don't think I've ever actually used get-in in a program
11:53	Chouser	I've used update-in, but not get-in
11:54	Drakeson	I used to do a lot of matrix processing (using MATLAB). It was hard to replicate in CL, (no "good" support for vectors, no compact syntax for vectors, etc.)
11:55	Drakeson	so I would appreciate having many array-related facilities
11:57	Drakeson	in matlab 1:10 means (range 1 10), and a[1:10] is produces a sub-array of "a" with elements 1,2,...,10.
11:57	Drakeson	(a <vector>) could mean the same (i.e. (map a <vector>))
12:22	duck1123	what does "Can't let qualified name: view/session" mean?
12:23	Chouser	it means you're writing a macro
12:23	duck1123	session is one of my variable, but not on the line it says
12:23	duck1123	yes
12:23	kotarak	use '~ in the macro
12:23	Chouser	if you're trying to capture a name, right, use '~
12:23	Chouser	if you're not trying to, use gensym or foo#
13:06	lisppaste8	duck1123 pasted "Compojure putting 'POST' in namespace" at http://paste.lisp.org/display/69557
13:07	duck1123	could someone help me figure out why this isn't working?
13:07	duck1123	I can do forms just fine, except for when they're in a macro
15:15	Lau_of_DK	When experimenting with Gen-class, Im not allowed to create multiple objects with the same name (my wish was of course to overwrite) - how do I get around this limitation ?
15:20	Lau_of_DK	Come on gents, can somebody please help me a little with these classes?
15:20	gnuvince_	Good day
15:21	Lau_of_DK	Good evening Vincent
15:36	Lau_of_DK	Anybody here who can share a few words on java classes, and then perhaps gen-class?
15:49	sohail	Lau_of_DK, that's probably a Java thing
15:50	Lau_of_DK	ok - how do I go around it?
15:50	Lau_of_DK	I cant come up with a new name everytime I test-run the class
15:50	sohail	Lau_of_DK, you might have to
15:52	Lau_of_DK	hehe
15:52	Lau_of_DK	sohail are you proficient in Java?
15:53	sohail	Lau_of_DK, not at all :-)
15:54	Lau_of_DK	alrighty
17:11	Lau_of_DK	user=> (gen-and-load-class "HLayout" :method [["getLayout" [] QWidget]])
17:11	Lau_of_DK	#=HLayout
17:11	Lau_of_DK	user=> java.lang.IllegalArgumentException: Unable to resolve classname: HLayout (NO_SOURCE_FILE:35)
17:11	Lau_of_DK	So first it generates the class, and the it denies any knowledge of having done so ?
17:12	kotarak	Lau_of_DK: use 'some.namespace.HLayout and then import.
17:14	Lau_of_DK	right... :)
17:14	Lau_of_DK	Now I caused Java to throw a Segfault
17:25	danlarkin	is it possible to have the slime REPL print the return value of a form when I eval it from another buffer with C-x C-e?
17:26	Chousuke	it prints it in the minibuffer doesn't it?
17:27	danlarkin	if I have (first [1 2]) in my buffer and I eval it slime just prints: ;;;; (first [1 2]) ...
17:28	danlarkin	does it print 1 for you?
17:49	Chousuke	danlarkin: in the minibuffer it does.
17:49	danlarkin	Chousuke: ahh look at that. fantastic! Thanks :)
18:57	Lau_of_DK	Is Java supposed to automatically use .class file on the classpath, or is it only .jar ? And if its the case, are they supposed to maintain their original libraries hierachy, like /foo/bar/Baz.class ?
19:09	StartsWithK_	Lau_of_DK: sure, you can have directories with .class files and then you could just add them to class path with something like -cp rootdir
19:11	Lau_of_DK	so if I have /home/lau/code/com/lau/net/.class and I need the namespace .com.lau.net
19:11	Lau_of_DK	How do I add that to CP ?
19:19	AWizzArd	Oh, Bill Clementson now also tries out Clojure
19:38	danlarkin	is there a predicate that will be true for vectors and lists but not maps?
19:38	danlarkin	aside from (or (vector? foo) (list? foo))
19:47	Chousuke	(compose not map?)
19:47	Chousuke	;P
19:47	Chousuke	comp* too
19:48	danlarkin	heh, mostly I wanted a name for my function... I'm going with decode-list-vector
19:48	danlarkin	even though it's kindof a lame name
19:49	Chousuke	if it's going to be a predicate to test whether it's a list or a vector, why not just list-or-vector?
19:50	Chousuke	with the ? in the name
19:52	danlarkin	lisppaste8: url
19:52	lisppaste8	To use the lisppaste bot, visit http://paste.lisp.org/new/clojure and enter your paste.
19:52	lisppaste8	danlarkin pasted "example" at http://paste.lisp.org/display/69570
19:53	danlarkin	oh... formatting got messed up, but you see what I'm going for?
19:53	danlarkin	I decided to just exploit the procedural nature of cond and put map? before coll?
19:55	StartsWithK_	is there a zipper that can work with all clojure data strucutures (maps and sets too)?
19:56	StartsWithK_	or, what would be a best way to scan macro body for specific code fragments?
19:56	Chousuke	danlarkin: don't forget that sets are collections too
19:58	danlarkin	Chousuke: whoops! Luckily it turns out I want sets to be processed the same way as lists & vectors. Too bad decode-list-or-vector-or-set is a horrible name
19:58	danlarkin	I guess I'll go with decode-coll
19:59	Chousuke	or decode-nonmap
20:40	danlarkin	anyone familiar with cond-let from clojure-contrib? I'm getting java.lang.Exception: Unsupported binding form: clojure.lang.PersistentList@e2c88ceb
20:42	lisppaste8	danlarkin pasted "cond-let" at http://paste.lisp.org/display/69573
21:41	danlarkin	So how's everyone getting around having two functions that call eachother
21:41	danlarkin	since one has to be defined first
21:53	Chouser	(def foo) first, then you can write a function that calls foo.
21:53	Chouser	re-def foo later.
21:57	danlarkin	Mmm :-/
22:19	danlarkin	Anyone have a need for a custom Throwable yet? I guess you've gotta use gen-class to get that eh
22:22	Chouser	if you want to know what name to use when you catch it, yeah.
22:26	danlarkin	Chouser: I guess I'll stick with Exception for the time being
23:00	danlarkin	So I wrote a simple little JSON encoder, what kind of directory structure and files should I make to upload to github?
23:03	Chouser	at least directories that match the namespace: org.danlarkin.json should be defined in org/danlarkin/json/json.clj
23:03	Chouser	it seems common to put another src dir above that (src/org/dan...)
23:04	danlarkin	is it acceptable to have a namespace with no dots? (ns clojure-json)
23:05	danlarkin	I know it's possible, but is it frowned upon or something...
23:06	Chouser	well, I think clojure sort of adopts Java's conventions there, where they recommend using a domain name you control in order to avoid conflicts.
23:06	Chouser	http://java.sun.com/docs/books/jls/third_edition/html/packages.html
23:07	danlarkin	Ah
23:07	Chouser	especially section 7.7, I guess.
23:09	danlarkin	just seems egomaniacal for me to make everyone type org.danlarkin.json
23:09	danlarkin	:)
23:09	Chouser	heh.
23:09	Chouser	actually, it's the other way around -- might be egomaniacal to assume clojure-json means your package.
23:11	Chouser	it's why we have use and alias for packages. I can say (ns mything (:require [org.danlarkin.json :as json])) at the top of my file, and then just json/print or whatever when I want to use it.
23:11	danlarkin	so I'll have a README, LICENSE and src/org/danlarkin/json/json.clj -- should I be providing an ant build file too or something?
23:12	Chouser	I don't know. I've never written an ant build file.
23:13	Chouser	I guess if you want to let people download a .jar instead of making them use git, then you'll have to package it up -- you should provide the script or whatever you use to do that packaging, I suppose.
23:14	danlarkin	well to use this json encoder one would presumably have to make a jar and add it to the classpath, is that correct?
23:15	Chouser	no, you can add the src directory to your classpath
23:15	Chouser	that's how I use clojure-contrib. git svn rebase to keep it current, and clojure-contrib/src in my classpath. No rebuilding anything.
23:16	danlarkin	ah ha, that is better than building it indeed
23:59	danlarkin	tada http://github.com/danlarkin/clojure-json/tree/master