#clojure – 2009-04-09

2009-04-09

01:22	hiredman	~jdoc java.util.LinkedList
01:54	scottj_	I have some html that is not standards compliant and I would like to use xml-seq with it. It appears that xml-seq needs parse which only works with standards-compliant xml. am I missing something?
02:12	spaceman_stu	hm. When I launch my compojure site from the repl, it can't find the public directory I set up with images, etc
02:12	spaceman_stu	rather, launch from slime
02:13	spaceman_stu	it's behaving as though it's not referencing directories from the app's root
02:13	spaceman_stu	is that a .emacs setting?
02:15	scottj_	probably referencing it from whatever directory was the working directory when you started slime. C-x C-f will try to open a file in the current working directory I think
02:15	hiredman	I think compojure looks for a directory called public in the cwd
02:15	spaceman_stu	cool. So how would I change the cwd?
02:16	hiredman	it is where you start clojure
02:17	scottj_	spaceman_stu: don't really know the best way. you could open a file in the directory you want to be your cwd and then launch slime from there, maybe
02:17	scottj_	I don't know if ,cd in slime changes the cwd, or whether you need to do that before you load your compojure code
02:20	spaceman_stu	looks like M-x cd is what I'm looking for. THanks both of you
02:31	hiredman	~mock objects?
02:31	clojurebot	Your mock object is a joke; that object is mocking you. For needing it. -- rhickey
03:21	AWizzArd	Moin moin
03:23	AWizzArd	~seen rhickey
03:23	clojurebot	rhickey was last seen quiting IRC, 318 minutes ago
03:24	AWizzArd	~max people
03:24	clojurebot	max people is 164
03:33	jdz	hmm, is there a function in core that composes functions?
03:33	jdz	i don't like how #(max (count %)) looks
03:34	jdz	hmm
03:34	jdz	those don't glue together anyway
03:34	jdz	but the question still remains
03:36	leafw	jdz: yes: comp
03:36	leafw	,(doc comp)
03:36	clojurebot	"([& fs]); 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."
03:36	jdz	ok, thanks
03:43	hiredman	,(pl ((inc � dec) 0))
03:43	clojurebot	java.lang.IllegalArgumentException: Wrong number of args passed to: core$dec
03:43	hiredman	,(pl inc � dec)
03:43	clojurebot	#<core$comp__3753$fn__3755 clojure.core$comp__3753$fn__3755@411379>
03:43	hiredman	,(pl (inc � dec 0))
03:43	clojurebot	0
03:44	hiredman	,(pl (range � inc 3))
03:44	clojurebot	(0 1 2 3)
05:02	AWizzArd	hiredman: what is this pl thing?
05:13	jdz	what would be a proper way to iterate over keyvals sequence (like :key1 val1 :key2 val2 etc) without first creating a map with apply?
05:14	jdz	by properly i mean at each iteration step getting a key/value pair
05:26	AWizzArd	like should have a header such as (defn like [[k v] & args] ...)
05:28	AWizzArd	or just take [& args] and have a (loop [[k v & rest] args, result []] ... (recur rest (conj result [v k])))
05:28	jdz	hmm...
05:29	AWizzArd	,(loop [[k v & rest :as all] '(:a 1 :b 2 :c 3), result []](if-not all result (recur rest (conj result [(inc v) k]))))
05:29	clojurebot	[[2 :a] [3 :b] [4 :c]]
05:31	AWizzArd	Does this get you started?
05:31	jdz	too bad "for" does not support this kind of destructuring...
05:31	jdz	yes, thanks
05:32	jdz	i have written so many loop/recur's that i'm trying to get rid of them
05:32	jdz	they have their place in utility functions, but not sprinkled all over the code
05:36	AWizzArd	They are as typical as loops are in any language, such as Javas for loop.
05:36	AWizzArd	It's everywhere :)
05:36	jdz	yes but i recently discovered "for" and many things can be written so much more clearly
05:37	AWizzArd	right
05:37	jdz	something like CL' s iterate would be awesome to have, though
05:37	jdz	and lazy!
05:47	AWizzArd	In principle I see it as a bug that it does not work with (for ..)
05:47	AWizzArd	The problem is the use of when-first in the for macro.
05:48	jdz	yes, i gathered as much
05:49	AWizzArd	The for macro needs a correction in my opinion.
05:50	AWizzArd	Currently it is hardwired into it that one takes only one element out of the collection.
05:52	hosiawak	,(doc pl)
05:52	clojurebot	"([& forms]); replaces a $ b with (a b) walking right to left replaces a � b with (comp a b) left to right ?a with (uncurry a) left to right ?a with (flip a) left to right"
05:59	antifuchs	so... plyntax?
06:07	Chousuke	jdz: partition might work too
06:08	jdz	Chousuke: yes, thank you.
06:11	jdz	,(for [[k v] (partition 2 '(:a 1 :b 2 :c 3))] [(inc v) k])
06:11	clojurebot	([2 :a] [3 :b] [4 :c])
06:11	jdz	looks so much better!
06:16	AWizzArd	jdz: but this is then again already much closer to the apply which you did not want to have
06:17	jdz	what apply?
06:17	jdz	the point is that i want function to accept a list of key/value pairs, not a map
06:18	jdz	like (defn foo [x y & keyvals] ..) instead of (defn foo [x y keyval-map] ...)
06:19	AWizzArd	Why? :)
06:19	jdz	and creating a map in-between feels worse than going through a sequence by two elements
06:20	jdz	because the first approach looks better at the call site
06:20	AWizzArd	It saves two chars: { and }
06:20	jdz	and many core functions work that way
06:20	jdz	and it also saves stress on my eyes
06:20	AWizzArd	Several of these core functions work this way to create a map.
06:21	jdz	yes, but they do not ask you to provide a map :)
06:21	AWizzArd	This is obviously necessary.
06:21	jdz	like assoc; there is a difference between assoc and merge
06:21	AWizzArd	Sure, how could you provide a map if your goal is to create one?
06:22	AWizzArd	,(conj {:a 1, :b 2} {:c 3})
06:22	clojurebot	{:c 3, :a 1, :b 2}
06:23	AWizzArd	The map is a really good data structure if you need key/value pairs.
06:23	jdz	i'd prefer (assoc {:a 1, :b 2} :c 3) to conj any time of day
06:24	AWizzArd	That's fine. But in that case you must already know what the target is.
06:25	jdz	target being?
06:25	AWizzArd	hashmap
06:25	jdz	in your context?
06:25	AWizzArd	,(conj (list 1 2 3) 0)
06:25	clojurebot	(0 1 2 3)
06:25	AWizzArd	,(conj (vector 1 2 3) 4)
06:25	clojurebot	[1 2 3 4]
06:26	jdz	i'm not getting the drift, sorry
06:26	AWizzArd	assoc is very good for documenting the code. It tells your readers that you explictly want to work on maps.
06:26	AWizzArd	But conj allows for more generic algorithms.
06:26	jdz	yes, and that is besides the point
06:27	AWizzArd	also in your example you will need to apply assoc to your & kv-pairs
06:27	AWizzArd	if that were a map you could just assoc them
06:27	jdz	no
06:28	AWizzArd	,(assoc {:a 10, :b 20} '(:c 30))
06:28	clojurebot	java.lang.IllegalArgumentException: Wrong number of args passed to: core$assoc
06:28	AWizzArd	,(apply assoc {:a 10, :b 20} '(:c 30))
06:28	clojurebot	{:c 30, :a 10, :b 20}
06:28	AWizzArd	vs
06:28	AWizzArd	,(assoc {:a 10, :b 20} {:c 30})
06:28	clojurebot	java.lang.IllegalArgumentException: Wrong number of args passed to: core$assoc
06:28	AWizzArd	cool
06:28	jdz	the point is that i don't want to create a map
06:29	jdz	i want my function to accept options
06:29	AWizzArd	To save the caller side from typing two more chars?
06:29	jdz	the caller should not be constructing maps just to please the callee
06:29	AWizzArd	Yes, like keyword args in CL.
06:29	jdz	all i want is to pass some options
06:29	jdz	constructing maps is just a clutter
06:29	AWizzArd	But how do you define the defaults?
06:30	jdz	if the callee wants to construct a map out of the options, it's callee's business
06:30	AWizzArd	The idiomatic Clojure design pattern is to pass a map and merge it with the defaults.
06:30	jdz	in my case i don't have defaults
06:30	AWizzArd	What if you want to add them later?
06:31	jdz	it would be no problem
06:33	jdz	well, it may be my exposure to CL being at work here; i'm sure i'll pick up clojure idioms while writing more code
06:33	AWizzArd	I also come from CL. And &key args would indeed be nice to have.
06:35	AWizzArd	It's just the closest bet we have in Clojure to pass maps. Those you can easily bind in a let with destructuring and merge.
06:35	AWizzArd	(defn foo [args] (let [{port :port, prot :protocol, url :url} (merge defults args)] ...))
06:36	AWizzArd	&key args always need to have a default. Without one they don't make sense.
06:37	AWizzArd	If you really have no defaults in your case then I don't see why the user has to pass in key/value pairs vs just values.
06:37	jdz	sometimes they do; like in my case: (node "node" :fontname "Helvetica" :fontsize 16 :fillcolor "white")
06:37	AWizzArd	What if the caller does not specify a :fillcolor?
06:38	jdz	then the :fillcolor is not being used.
06:38	jdz	i mean, is not being used in the output
06:38	AWizzArd	So the output will have no color?
06:38	jdz	i'm generating .dot files here
06:38	AWizzArd	What fontsize will be used?
06:38	jdz	the default graphviz font size
06:38	AWizzArd	You are implicitly using the defauts of .. yes
06:39	jdz	yes
06:39	jdz	and i don't want to create my own defaults and override graphviz's defaults with them
06:39	AWizzArd	Does anyone here remember why Clojure does not support key args?
06:40	jdz	they don't mesh very well with rest args :)
06:40	jdz	umm, the optional ones
06:40	AWizzArd	true
06:41	AWizzArd	I mean, CL has a way to handle that, but maybe Rich thought it would make Clojure too complicated.
07:29	Neronus	I guess because you can emulate this very well using maps or arraymaps
07:49	AWizzArd	genau
08:37	hosiawak	where can I find the def of pl clojurebot knows about ?
08:40	AWizzArd	You can ask the bot where its sources reside.
08:54	AWizzArd	Is there an X that allows me to say (X methodC methodB methodA (get-some-object)) instead of (.methodC (.methodB (.methodA (get-some-object))))? If yes, what is it?
08:54	AWizzArd	I am aware that I can do (-> (get-some-object) (.methodA) (.methodB) (.methodC)).
08:55	gnuvince	AWizzArd: ..?
08:55	jdz	i curious why would you want that...
08:55	gnuvince	(doc ..)
08:55	clojurebot	form => fieldName-symbol or (instanceMethodName-symbol args*) Expands into a member access (.) of the first member on the first argument, followed by the next member on the result, etc. For instance: (.. System (getProperties) (get "os.name")) expands to: (. (. System (getProperties)) (get "os.name")) but is easier to write, read, and understand.; arglists ([x form] [x form & more])
08:58	AWizzArd	.. seems to be doing what -> is doing.
08:58	gnuvince	(.. "Hello" length (equals 5) toString)
08:58	gnuvince	,(.. "Hello" length (equals 5) toString)
08:58	clojurebot	"true"
08:58	AWizzArd	But for this case it documents better what I want to do. Thanks gnuvince
08:58	gnuvince	np
08:58	gnuvince	,(macroexpand-1 '(.. "Hello" length (equals 5) toString))
08:58	clojurebot	(.. (. "Hello" length) (equals 5) toString)
08:59	AWizzArd	I thought I would want to have it as (.. toString (equals 5) length "Hello"), but the other way around it's perhaeps even better.
08:59	gnuvince	,(macroexpand '(.. "Hello" length (equals 5) toString))
08:59	clojurebot	(. (. (. "Hello" length) (equals 5)) toString)
09:09	AWizzArd	jdz: I want that to make it a bit easier for a human reader to parse what it means.
09:09	AWizzArd	That is probably the biggest use of ..
09:10	jdz	well yes, i was just wondering about the order of invocation (since it seemed that you wanted the opposite of ->)
09:11	AWizzArd	jdz: Yes, that was indeed my first idea. But now I like the order of .. (or ->) more :)
09:26	AWizzArd	Hi PJ.
09:31	ozzilee	Hey all. I wrote a java class in Clojure that I can compile and call with JSVC. JSVC calls the class's 'start' method...
09:32	ozzilee	I'd like to be able to run it from an ant task without compiling for development. Can I get clojure.lang.Script to do this?
09:33	ozzilee	Or do I need to compile, and maybe write another script to start it?
09:41	hosiawak	clojurebot: def pl
09:43	hosiawak	clojurebot: def aofjo
09:45	AWizzArd	clojurebot: where are your sources?
09:45	clojurebot	I don't understand.
09:45	AWizzArd	clojurebot: where is your source?
09:45	clojurebot	source is http://github.com/hiredman/clojurebot/tree/master
10:01	pjstadig	AWizzArd: hi
10:21	cconstantine	booo! java regex is broken, so I can't do what I want in clojure :(
10:21	cconstantine	no named captures == broken
10:23	gnuvince	why?
10:23	gnuvince	It's a missing feature for sure, but I wouldn't call it broken
10:23	cconstantine	I shamelessly thing of Perl's regex as canonical, so if Perl's regex can do it anyone should be able to
10:24	cconstantine	s/thing/think
10:25	Cark	basic regex is easy, full blown and optimized is hard
10:25	cconstantine	yeah, with lookahead/behind and all that
10:26	cconstantine	even perl doesn't optimize as much as it could
10:26	Cark	have a look to http://www.weitz.de/cl-ppcre/ for a common lisp implementation
10:26	Cark	which is faster on some implementations than perl
10:26	cconstantine	Cark: I've had much luck with that. I was looking to re-write my fancy-grep in clojure based on my CL implementation
10:27	gnuvince	I don't see the point of rewriting the regex engine when there's one that works pretty darn well
10:27	cconstantine	My CL implementation wasn't very lisp-y anyway
10:27	cconstantine	no named captures... my fancy-grep is based around that feature
10:27	gnuvince	Especially if you can't use your own with Java libs
10:27	Chouser	named capture in perl is pretty new, isn't it?
10:27	gnuvince	Chouser: 5.10
10:27	gnuvince	Python had it way before
10:28	Chouser	I have a whole project written in python because I wanted named capture and neither perl nor ruby had it.
10:28	Cark	anyways if you need named capture, you might want to look into soime parser library instead ?
10:28	cconstantine	I know the CL, and o-caml implementations had it over a year ago.
10:28	frodwith	Parser::RecDescent, for instance.
10:30	cconstantine	eh, I have an implementation of my fancy-grep in python also (used it to learn both CL and python). I was hoping to implement it in clojure as a learning experiance
10:31	AWizzArd	Is there a way to list all namespaces which Clojure currently knows? (because of using/requiring Clojure libs)
10:32	cconstantine	Chouser: I'd avoid writing whole project in perl... but that's because I've never been able to write a non-trivial perl program/script and maintain it.
10:32	AWizzArd	,(doc all-ns)
10:32	clojurebot	"([]); Returns a sequence of all namespaces."
10:33	AWizzArd	oki
10:36	eyeris	If I have a string who's contents name a function, how can I call that function?
10:37	pjstadig	,(apply (eval "str") 1 2 3)
10:37	clojurebot	DENIED
10:37	pjstadig	d'oh
10:39	pjstadig	(apply (ns-resolve ns (symbol "str")) 1 2 3)
10:39	pjstadig	,(apply (ns-resolve ns (symbol "str")) 1 2 3)
10:39	clojurebot	java.lang.IllegalArgumentException: Don't know how to create ISeq from: Integer
10:39	pjstadig	,(apply (ns-resolve ns (symbol "str")) [1 2 3])
10:39	clojurebot	"123"
10:39	pjstadig	,((ns-resolve ns (symbol "str")) 1 2 3)
10:39	clojurebot	"123"
10:40	eyeris	((symbol "str") [1 2 3])
10:40	eyeris	,((symbol "str") [1 2 3])
10:40	clojurebot	nil
10:40	eyeris	,((symbol "str") 1)
10:40	clojurebot	nil
10:40	pjstadig	you would have to resolve the symbol to a var
10:40	eyeris	Oh, right
10:41	pjstadig	,((resolve (symbol "str")) 1 2 3)
10:41	clojurebot	"123"
10:41	pjstadig	if you want to specify a specific ns i guess you'd use the ns-resolve
10:41	pjstadig	~def resolve
10:42	pjstadig	resolve is the same thing as (ns-resolve ns sym)
10:42	pjstadig	,(resolve "str")
10:42	clojurebot	java.lang.ClassCastException: java.lang.String cannot be cast to clojure.lang.Symbol
10:45	eyeris	Thanks. That worked.
10:45	pjstadig	np
11:23	eyeris	How can I get the length of a Java array?
11:23	slashus2	.length ?
11:23	pjstadig	(doc alength)
11:23	clojurebot	Returns the length of the Java array. Works on arrays of all types.; arglists ([array])
11:24	eyeris	ah!! alength!
11:24	pjstadig	most of the array functions start with an 'a' as a prefix
11:24	pjstadig	so they are conveniently grouped on http://clojure.org/api
11:25	Chouser	kinda interesting that I've never needed that.
11:25	eyeris	This is so annoying. I've spent 3 hours tracking down phantom bugs in my clojure code, only to find out that this java Excel library is broken
11:26	pjstadig	(.length (to-array [1 2 3])
11:26	pjstadig	,(.length (to-array [1 2 3])
11:26	clojurebot	EOF while reading
11:26	eyeris	,(.length (to-array [1 2 3]))
11:26	clojurebot	java.lang.IllegalArgumentException: No matching field found: length for class [Ljava.lang.Object;
11:27	eyeris	,(count (to-array [1 2 3]))
11:27	clojurebot	3
11:27	eyeris	,(acount (to-array [1 2 3]))
11:27	clojurebot	java.lang.Exception: Unable to resolve symbol: acount in this context
11:27	eyeris	,(alength (to-array [1 2 3]))
11:27	clojurebot	3
11:27	slashus2	(.length (make-array Integer/Type 10))
11:27	slashus2	,(.length (make-array Integer/TYPE 10))
11:27	clojurebot	java.lang.IllegalArgumentException: No matching field found: length for class [I
11:29	eyeris	slashus2 .length is a property, not a method
11:29	slashus2	yeah
11:29	slashus2	I know
11:29	pjstadig	(amap (to-array [1 2 3]) i [] inc)
11:29	pjstadig	,(amap (to-array [1 2 3]) i [] inc)
11:29	clojurebot	java.lang.IllegalArgumentException: Argument is not an array
11:29	pjstadig	,(amap (to-array [1 2 3]) i (to-array []) inc)
11:29	clojurebot	java.lang.Exception: Unsupported binding form: (to-array [])
11:30	pjstadig	,(amap (to-array [1 2 3]) i ret (inc i ret))
11:30	clojurebot	java.lang.IllegalArgumentException: Wrong number of args passed to: core$fn
11:34	hosiawak	,(Integer/valueOf "2")
11:34	clojurebot	2
11:34	hosiawak	,(map #(Integer/valueOf) '(1 2 3))
11:34	clojurebot	java.lang.NoSuchFieldException: valueOf
11:35	hosiawak	how to pass Integer/valueOf to map ?
11:35	pjstadig	,(map Integer/valueOf '(1 2 3))
11:35	clojurebot	java.lang.Exception: No such namespace: Integer
11:35	Chousuke	#(Integer/valueOf %)
11:35	Chousuke	don't forget the parameter :P
11:36	Chousuke	,(map #(Integer/valueOf %) '(1 2 3)) ; like this
11:36	clojurebot	(1 2 3)
11:36	Chousuke	not very interesting though
11:36	hosiawak	,(map #(Integer/valueOf %) '("1" "2" "3"))
11:36	clojurebot	(1 2 3)
11:37	hosiawak	is there other way to get the integer value of a string ?
11:37	Chousuke	using vectors instead of quoted lists for literals is slightly more clojurey :)
11:37	Chousuke	Integer/parseInt
11:37	hosiawak	ok, thanks
12:19	kadaver	how would you implement types in clojure itself? i mean not writing a parser for a new language but jsut add it to clojure itself?
12:20	pjstadig	using maps, structs, and multimethods
12:24	kadaver	ok i did it with struct
12:25	kadaver	so basically you do it like with cons and cdr
12:25	kadaver	you jsut implement it as a function
12:26	kadaver	http://hpaste.org/fastcgi/hpaste.fcgi/view?id=3592#a3592
12:26	kadaver	haskell Maybe-type ^, is that how you would do it?
12:27	kadaver	and is there a function or macro for this: if x x y; ? instead do-if x y; so it will return the tested condition without me having to write it again as the then branch?
12:28	scottj_	Is there a way to use xml-seq with bad html? the parse function is too strict for most webpages.
12:29	stuarthalloway	kadaver: if-let
12:30	kadaver	(defn neat-if [a b]
12:30	kadaver	(if a a b))
12:30	kadaver	is what i want
12:32	Chouser	kadaver: or
12:37	AWizzArd	rhickey: Are you aware of the suggestions in this video? http://www.infoq.com/presentations/click-fast-bytecodes-funny-languages
12:39	hiredman	AWizzArd: I am interested to hear what you think the suggestions from the video are
12:41	AWizzArd	Dr. Click explains that he found some ways how Clojures bytecode could be improved to be more efficient. I don't understand in detail what he is talking about. But maybe rhickey does understand it, and perhaps there is new info waiting for him. So, I am just interested if he is aware.
12:42	rhickey	AWizzArd: I was there and spent a lot of time with Cliff. At the time, Clojure didn't inline all the ops in his test, it now does, he's seen that, and it's the same as Scala on his benchmark
12:42	AWizzArd	Oki, thanks.
12:48	stuarthalloway	rhickey: got two compiler questions for you: (1) any reason bytecode would blow up coverage tools? and (2) how would I compile to avoid this warning: "EMMA: package [clojure/contrib] contains classes [test_is__init] without full debug info"?
13:27	eyeris	Could someone tell me what I am doing wrong that is making Clojure fail to find this Java method? http://pastebin.ca/1387241
13:28	stuarthalloway	eyeris: getRefersToFormula sounds like the name of a getter method, not a field
13:30	eyeris	It is a method.
13:31	stuarthalloway	I don't see Clojure code in the paste, just a stack trace
13:31	eyeris	Here it is: http://pastebin.ca/1387245
13:33	stuarthalloway	can you try calling bean on the object to see what properties it does expose?
13:36	eyeris	The output of bean is appended here: http://pastebin.ca/1387247
13:37	eyeris	Though isn't the problem that clojure thinks I am accessing a field instead of a method?
13:37	stuarthalloway	no, the message is a little misleading
13:38	stuarthalloway	,(.toUpperCase "foo")
13:38	clojurebot	"FOO"
13:38	stuarthalloway	,(.toNonexistentPlace "foo")
13:38	clojurebot	java.lang.IllegalArgumentException: No matching field found: toNonexistentPlace for class java.lang.String
13:38	eyeris	Oh. Ok.
13:39	stuarthalloway	the bean info may be the clue -- it includes deprecated names and does not include the name you want
13:39	stuarthalloway	old version of the jar?
13:40	eyeris	Does getRefersToFormula being defined in an interface, and implemented in the class complicate matters with bean?
13:40	eyeris	No, it's the newest jar.
13:40	eyeris	What do you mean by "deprecated" names?
13:41	stuarthalloway	according to http://poi.apache.org/apidocs/org/apache/poi/hssf/usermodel/HSSFName.html, the property "reference" is deprecated
13:41	eyeris	perhaps that documentation doesn't refer to the latest release, but some in-development realease...
13:43	eyeris	Yep
13:43	eyeris	That's it
13:43	eyeris	I will track that down after lunch :)
13:43	eyeris	thanks for helping me track that down.
13:43	stuarthalloway	good luck
13:47	cemerick	the fact that (not= (delay 5) 5) has become a serious inconvenience, especially in the context of map and vector equality
13:48	cemerick	does anyone see any potential issues with the notion of building a c.l.Delay subclass that provides equals and hashcode impls that always force the delay's value and delegate such calls to that value?
13:52	Chouser	you want every delay in a key or value of a map forced if you test = on that map?
13:52	cemerick	in certain circumstances, yeah
13:52	cemerick	or, actually, in most circumstances, actually
13:53	cemerick	...maybe that's a sign I'm doing things wrong in a fundamental way....?
13:57	Chouser	cemerick: I couldn't say -- I've not used delay at all.
13:57	Chouser	people have previously asked for other operations to auto-force, such as math operators.
13:57	Chouser	are you sure you're only going to want hash and = ?
13:58	cemerick	well, auto-forcing isn't really appropriate across the board, I don't think (Rich semi-convinced me of that some time ago)
13:58	cemerick	I think that's all that's necessary in order to get maps and vectors to work properly.
13:59	twism	clojure question... when (let [kws (keys a-map)] ...) would (last kws) be equal to the last kw in a (doseq [kw kws] ...)?
14:00	twism	if that makes any sense
14:00	twism	of course i cold just test it out
14:02	twism	but it equality could be true by chance
14:03	twism	am i making sense or am i being stupid
14:04	pjstadig	twism: are you asking about a stable iteration ordering?
14:04	lisppaste8	cemerick pasted ""transparent" delays" at http://paste.lisp.org/display/78320
14:05	cemerick	that feels wrong, somehow....
14:07	twism	pjstadig: basically are the keywords of maps when returned by the "keys" fn ordered the same?
14:07	Chouser	twism: every time get a seq for the same map's keys, the seq will have those keys in the same order.
14:08	twism	Chouser: thanks i thought so
14:08	Chouser	as soon as you add anything or removing anything from the map, I wouldn't rely on the order being at all the same.
14:08	twism	ok
14:08	twism	gotcha
14:08	twism	thanks again
14:08	Chouser	cemerick: wrong because it was so easy to implement?
14:09	cemerick	heh, that's the good part!
14:09	cemerick	No, I just know I've planted some pretty difficult-to-track bugs for myself when I start screwing with identity like that.
14:09	cemerick	in the past, that is
14:17	dakrone_hb	can someone give me a hand with some refactoring? I have this code: http://gist.github.com/92640 and I think I need to switch it around to better operate on each line rather than loading the entire thing into memory...
14:22	hiredman	if use exec directly you get an outputstream from the process
14:22	hiredman	you can wrap the os with a bufferedreader, then call line-seq on it
14:23	Chouser	don't forget to clean up the streams and process when you're done
14:23	Neronus	but don't close it before line-seq has seen it all, or you're dead... or something less worse
14:23	Neronus	less worse
14:24	Neronus	that doesn't sound correct to me
14:24	Neronus	less bad
14:24	hiredman	which is why you should use a scope
14:24	Chouser	dakrone_hb: shell-out doesn't let you get at the streams or the process directly precisely because that's a whole lot to worry about for those many cases where getting a single string is sufficient.
14:24	Neronus	or write your own lineseq
14:24	dakrone_hb	hiredman, were you talking to me when you said exec?
14:25	dakrone_hb	so, I need to write something that will let me operate on a single line with a function, without loading all the lines into memory?
14:25	Neronus	which uses scoping, so... forget me :)
14:25	dakrone_hb	or does something already exist in this capacity?
14:26	hiredman	Runtime getRuntime exec?
14:28	dakrone_hb	hiredman, I was using this macro a while back: http://pacific.mpi-cbg.de/wiki/index.php/Clojure_Scripting#Executing_a_command_in_a_shell_and_capturing_its_output then Chouser suggested I use shell-out instead
14:29	hiredman	processing the output of a shell comand lazily is pretty silly
14:29	hiredman	the ouput is not generated on demand anyway
14:30	hiredman	it is just dumped into a buffer so it already exists
14:30	Chouser	well, a process will block waiting to write if the output buffer is full, won't it?
14:31	hiredman	I have no idea
14:31	Chouser	I think it does.
14:31	hiredman	I guess that depends on how java manages it
14:31	dakrone_hb	I believe that's what happens
14:32	pjstadig	i think the point still stands, you're not asking a shell command for its output, it is giving it to you
14:32	hiredman	dakrone_hb: http://java.sun.com/j2se/1.5.0/docs/api/java/lang/Runtime.html
14:33	pjstadig	so you process it based on the whim of the shell command, which means you don't really decide to be lazy
14:34	dakrone_hb	so instead of a line-seq, I'd use something that wasn't lazy, correct?
14:34	Chouser	you'll be dealing with lines not chunks of binary data or something?
14:35	hiredman	dakrone_hb: you are already doing that
14:36	dakrone_hb	Chouser, yes, dealing with another program that doesn't have an api, so I need to call it's executables, and then process each line of output to do different things with them
14:36	pjstadig	dakrone_hb: i don't think the OOME is coming from your code, but from the shell-out code that is trying to load all of the output at once
14:36	Chouser	dakrone_hb: in that case, a line-seq is probably appropriate
14:36	pjstadig	so if you use exec directly and read from the stream incrementally, then you wouldn't error out
14:37	Chouser	but shell-out isn't going to help you at all as it stands
14:37	dakrone_hb	so doing a (read <stream>) only return 1 line at a time?
14:37	Chouser	dakrone_hb: you're name's not Kyle is it?
14:37	hiredman	Chouser: it might be nice to have something like ruby's IO.popen
14:38	dakrone_hb	Chouser, no, why do you ask?
14:38	hiredman	well
14:38	dakrone_hb	yea, a popen is exactly what I need
14:38	Chouser	someone named kyle is asking for similar features for shell-out
14:38	hiredman	with readlines.each
14:38	dakrone_hb	oh, well that wasn't me
14:38	hiredman	basically a combination of with-open an shell-out
14:38	hiredman	with-open-proc
14:39	Chouser	the reason it doesn't have it already is because it forces the user to mange the closing of streams and the cleaning up of the process
14:39	Chouser	and there are a lot of simple use cases where getting a String back is fine, so it's nice to not worry about all that.
14:39	kadaver	what do you people prefer with Clojure over Haskell?
14:39	hiredman	(with-open-proc "echo foo" [stdin stdout stderr] (do stuff))
14:40	Chouser	I think these more advanced usages warrent a bit more design and thought.
14:41	hiredman	kadaver: I like lisp and clojure has easy access to all the millions of java libraries
14:42	rsynnott	because haskell is, well, haskell ;)
14:43	pjstadig	kadaver: i know Clojure, and I do not know Haskell
14:44	hiredman	there was a great quote
14:44	dakrone_hb	Chouser, I look forward to additions to the shell-out library ;) in the meantime I will try to hack something up with my limited knowledge of it
14:45	hiredman	#clojure.log:2009:Feb:10:16:37:16 ayrnieu : you have to see features like that in the context of Haskell's community, which is something like Perl's community in the garden of Eden: detached from all shame or need to do any work.
14:46	Neronus	lol
14:46	dakrone_hb	hiredman, Chouser, pjstadig, thanks for the help :)
14:46	pjstadig	np
14:47	kadaver	hiredman: what feature was that?
14:47	hiredman	I forget
14:48	kadaver	I used to use Clojure (got interested in functional programming via Python) and I thought at first Haskell was too facist functional but after some time in Clojure and really grokking functional programming then I loved Haskell the next time I tried it.
14:48	hiredman	clojurebot: logs?
14:48	clojurebot	logs is http://clojure-log.n01se.net/
14:50	hiredman	http://clojure-log.n01se.net/date/2009-02-10.html#19:37
14:50	hiredman	for context
14:50	hiredman	the context was infix operators, I believe
14:51	hiredman	,(pl inc $ inc $ inc $ 0)
14:51	clojurebot	3
14:51	pjstadig	?
14:52	kadaver	if you don't have macros int he lisp-sense then infix-math is nice...
14:52	hiredman	,(macroexpand `(pl inc $ inc $ inc $ 0))
14:52	clojurebot	(do (clojure.core/inc (clojure.core/inc (clojure.core/inc 0))))
14:52	pjstadig	(doc pl)
14:52	clojurebot	Huh?
14:52	hiredman	,(doc pl)
14:52	clojurebot	"([& forms]); replaces a $ b with (a b) walking right to left replaces a � b with (comp a b) left to right ?a with (uncurry a) left to right ?a with (flip a) left to right"
14:52	pjstadig	oh
14:53	hiredman	pl is not in clojure.core so (doc pl) doesn't pick it up
14:53	hiredman	,(doc uncurry)
14:53	clojurebot	"([x]); applied to a function it returns a function that will continue partially applying until it is called with no arguments"
14:53	pjstadig	hiredman: is there a way to get clojurebot to show the definition of a non-core function?
14:53	hiredman	,(((uncurry +) 1) 2)
14:53	clojurebot	#<sandbox$uncurry__1858$uc__1860 sandbox$uncurry__1858$uc__1860@8443a3>
14:53	pjstadig	~def parallel.par
14:54	hiredman	ha ha
14:54	pjstadig	~def clojure.parallel.par
14:54	pjstadig	~def clojure.parallel/par
14:55	hiredman	,(require '[clojure.parallel :as p])
14:55	clojurebot	java.io.FileNotFoundException: Could not locate clojure/parallel__init.class or clojure/parallel.clj on classpath:
14:56	pjstadig	it needs to to be required to post a url?
14:56	hiredman	clojure needs to be able to resolve the symbol
14:56	hiredman	I don't have the funky jars needed for parallel.clj
14:56	pjstadig	k
14:57	hiredman	,((((uncurry +) 1) 2))
14:57	clojurebot	3
14:57	pjstadig	~def clojure.set/union
14:57	pjstadig	gotcha
15:00	hiredman	fail whale
15:00	hiredman	I think this is my first (shows how 2.0 I am)
15:00	pjstadig	my first was just a couple of days ago
15:00	hiredman	http://twitter.com/boscoh/statuses/1484205898 <-- ouch
15:01	pjstadig	but then i only joined twitter like last month
15:02	hiredman	you know, clojurebot has a twitter...
15:02	cemerick	whoa, dude's got some rage
15:04	pjstadig	i like having my brain turned inside out by new ideas....but maybe i'm just weird
15:07	hiredman	I just don't get it
15:07	hiredman	functions are like the simplest thing ever
15:08	cemerick	not having mature tools can often trip people up pretty easily
15:09	pjstadig	it's maybe simple once you get it, but it takes people a while to give up their for loops
15:09	hiredman	clojurebot: functions?
15:09	clojurebot	anonymous functions are functions with no names
15:10	hiredman	clojurebot: functions is <reply>functions are maps
15:10	clojurebot	You don't have to tell me twice.
15:10	hiredman	clojurebot: maps?
15:10	clojurebot	Titim gan �ir� ort.
15:10	hiredman	clojurebot: maps is <reply>maps are functions
15:10	clojurebot	You don't have to tell me twice.
15:20	dhaas	are there any particular windowing toolkits that mesh well with clojures way of doing things?
15:21	hiredman	there are some miglayout (swing layout manager) wrappers in contrib
15:21	hiredman	some seem to like QT's java bindings, but those have been discontinued
15:23	hiredman	I would just swing, just watch out for the event dispatch thread
15:24	hiredman	jcip has a short section on concurrent guis, which made me re-think my opinion of swing
15:26	durka42	for the better or worse?
15:26	hiredman	it made me appreciate the need for all the EDT redtape
15:27	hiredman	http://weblogs.java.net/blog/kgh/archive/2004/10/multithreaded_t.html
15:28	hiredman	I still hate writing guis, and avoid it
15:28	hiredman	clojurebot: <3
15:28	clojurebot	Huh?
15:28	cemerick	hiredman: jcip?
15:29	hiredman	clojurebot: jcip?
15:29	clojurebot	I don't understand.
15:29	pjstadig	java concurrency in practice
15:29	cemerick	ah
15:29	hiredman	clojurebot: jcip is Java Concurrency in Practice
15:29	clojurebot	Ack. Ack.
15:29	cemerick	still haven't read that :-(
15:29	Chousuke	clojurebot: <3 is <3
15:29	clojurebot	Ok.
15:29	Chousuke	clojurebot: <3 is also </3
15:29	clojurebot	Ik begrijp
15:29	pjstadig	clojurebot: <3
15:29	hiredman	~<3 is also ?
15:29	clojurebot	Roger.
15:29	clojurebot	<3 is </3
15:30	Chousuke	hm
15:30	pjstadig	clojurebot: <3
15:30	clojurebot	<3 is <3
15:30	Chousuke	needs <reply>
15:30	hiredman	clojurebot: literal [?] <3
15:30	clojurebot	3
15:31	hiredman	~<3 is also <reply>?
15:31	clojurebot	c'est bon!
15:57	bradford	suppose i have a seq generated by file-seq
15:58	bradford	how would i find all jars?
15:59	cp2	(filter #(.endsWith "jar" (.getName %)) blah)
15:59	cp2	i guess
16:00	cp2	oh oops
16:00	Chouser	(filter #(.endsWith (str %) ".jar") blah) ?
16:00	cp2	#(.endsWith (.getName %) ".jar") rather
16:06	bradford	(def files-and-dirs (file-seq (new File "~/opt/capjure")))
16:06	bradford
16:06	bradford	(filter #(.endsWith (str %) ".jar") files-and-dirs)
16:06	bradford	i'm getting an empty seq back
16:06	bradford	thought i know there are jars under there
16:07	hiredman	decompose and examine intermediate results
16:14	dhaas	i hate writing GUIs as well, but they are still quite useful :(
16:16	bradford	ah, i was being dumb. :-) the result of filter is also lazy so i need to force it to see results
16:49	dhaas	im trying to do an import once im in a namespace
16:49	dhaas	(in-ns 'foo) ........ (clojure/refer 'clojure)
16:49	dhaas	but it doesnt think clojure is a valid ns...?
16:51	hiredman	clojure.core
16:54	dhaas	its having a problem resolving clojure/refer
16:54	dhaas	java.lang.Exception: No such var: clojure/refer (NO_SOURCE_FILE:1)
16:55	pjstadig	,clojure.core/refer
16:55	clojurebot	#<core$refer__4341 clojure.core$refer__4341@18600d7>
16:56	pjstadig	,clojure/refer
16:56	clojurebot	java.lang.Exception: No such namespace: clojure
16:56	dhaas	ah:)
16:56	hiredman	dhaas: there is no clojure namespace
16:56	dhaas	understood
16:56	dhaas	(now)
16:57	hiredman	now as of five (six?) months ago
16:59	AWizzArd	~ def time
17:02	kefka	,(let [rg (set (range 50000))] (count (set rg)))
17:02	clojurebot	50000
17:02	kefka	,(let [rg (set (range 50000))] (time (count (set rg))))
17:02	clojurebot	50000
17:02	clojurebot	"Elapsed time: 210.43 msecs"
17:03	kefka	It costs significant time to call set on a large object that's already a set.
17:04	pjstadig	,(let [rg (set (range 50000))] (count rg))
17:04	clojurebot	50000
17:04	pjstadig	,(let [rg (set (range 50000))] (time (count rg)))
17:04	clojurebot	50000
17:04	clojurebot	"Elapsed time: 0.04 msecs"
17:04	pjstadig	~def set
17:05	hiredman	set calls seq first
17:05	hiredman	oh
17:05	hiredman	oops
17:06	hiredman	looking at the wrong def
17:08	kefka	,(doc set)
17:08	clojurebot	"([coll]); Returns a set of the distinct elements of coll."
17:08	hiredman	well, someone has to ask
17:08	pjstadig	~def hash-set
17:08	hiredman	why call set on a set?
17:08	kefka	Calling set on a collection that may be a set.
17:14	eyeris	Uhm, how do I exit the repl?
17:14	pjstadig	(System/exit 0)
17:14	cp2	you may not leave :)
17:14	hiredman	I usually use control-d
17:15	eyeris	Yeah, ^d doesn't work on Windows. Neither does ^z^z for some reason
17:16	hiredman	yet another strike against windows...
17:16	pjstadig	to exit on window, insert unbuntu cd, go to start=>restart and install
17:17	cp2	actually its start -> turn off computer -> restart
17:17	pjstadig	oh you're right....that makes much more sense...
17:18	hiredman	start -> cmd.exe -> figure out the syntax for the shutdown command -> shutdown
17:18	cp2	that is true hiredman
17:18	pjstadig	you mean start -> run "cmd.exe"?
17:18	cp2	yes
17:18	cp2	or winkey + r
17:18	cp2	!
17:18	hiredman	ah, depends
17:19	hiredman	you might have cmd.exe in your start menu, or have vista with the search thinger
17:19	hiredman	so you just type "cmd.exe" and it finds it, and you hit enter
17:25	Chouser	^Z<enter>
17:31	eyeris	Is there a clojure api wrapper for Double/parseDouble?
17:32	hiredman	why would you need one?
17:32	hiredman	,(Double/parseDouble "1.0")
17:32	clojurebot	1.0
17:32	hiredman	~javadoc Double
17:33	hiredman	looks even simpler then Integer/parseInt
17:35	duncanm	it'd be nice if the api page on clojure.org contains examples, particularly for the macros
17:35	eyeris	But (dbl "1.0") would be cooler :)
17:36	eyeris	duncanm or at least a link at the top of the page to the examples page
17:36	Chouser	~examples
17:36	clojurebot	examples is http://en.wikibooks.org/wiki/Clojure_Programming/Examples/API_Examples
17:37	duncanm	i wanted to know how IF-LET looks
17:37	duncanm	(if-let [x 0] test? then-clause else-clause) ?
17:39	slashus2	duncanm: You mean having non-trivial examples in the doc strings?
17:40	Chousuke	duncanm: (if-let [x whatever] whatever-is-true whatever-is-false)
17:40	Chouser	people say that a lot. what is "non-trivial"
17:40	duncanm	Chouser: where's the test, then?
17:40	Chousuke	it's basically (let [x whatever] (if x ...))
17:41	duncanm	oh!
17:41	slashus2	Chouser: I think a concise example that demonstrates the core usage of the api item is good enough.
17:42	duncanm	it says bindings => binding-form test in the docs
17:42	duncanm	it's kinda hassle that metadata associated with a list 'l' is not preserved in (rest l)
17:42	duncanm	it makes sense, but it's a hassle
17:43	bradford	if want to go over a seq and call a func with each element of the seq, what is the right way..its like an each in ruby
17:43	pjstadig	(doc doseq)
17:43	clojurebot	Repeatedly executes body (presumably for side-effects) with bindings and filtering as provided by "for". Does not retain the head of the sequence. Returns nil.; arglists ([seq-exprs & body])
17:43	duncanm	bradford: do you want to get a seq back?
17:43	duncanm	MAP or DOSEQ
17:43	bradford	nope, not getting a seq back..its not a map
17:44	duncanm	then doseq
17:44	pjstadig	use doseq for side effects and map if you are transforming the seq
17:44	duncanm	(doseq [i '(1 2 3)] (println i))
17:44	bradford	yea, its causing side effects
17:44	bradford	cool, thx
17:52	bradford	ok, so if i throw a println in to see that my seq contains what i think in contains, how do is see the resutsl if i do a slime-eval-region?
18:01	bradford	i'm such a fool - it all sows up in the repl of course :-)
18:06	dakrone_hb	are there any already-built libraries for Clojure+Lucene?
18:10	Chouser	dakrone_hb: stuart sierra's apparently using it, though I don't know exactly what it is: http://groups.google.com/group/clojure/browse_thread/thread/62600c60f5279b8e
18:11	bradford	what is the best way to concat a string ... file:// /foo/bar/baz -> file:///foo/bar/baz
18:11	cp2	(str "abc" "def")
18:12	dakrone_hb	Chouser, cool, I'll check it out, thanks
18:17	bradford	suppose i have a filter liek this: (filter #(.endsWith (.getName %) ".jar") files-and-dirs)
18:17	bradford	if i now want to extend the predicate to filter .jar and /src dirs, how to i add that?
18:21	hiredman	it depends on what files-and-dirs is a seq of
18:22	bradford	(def src (filter #(.endsWith (.getName %) "src") files-and-dirs)) ... is how I would filter if i defined it seperately
18:22	hiredman	it might be easier to half two filters one for jar files and one for directories named "src"
18:22	bradford	yea, that is what i have now
18:22	hiredman	well
18:22	hiredman	that is easy
18:22	bradford	perhaps i will jsut stick to that
18:22	hiredman	just use or
18:22	hiredman	#(or (.endsWith (.getName %) "src") (.endsWith (.getName %) ".jar"))
18:23	hiredman	(def jar-filter (partial filter #(.endsWith (.getName %) ".jar")))
18:23	hiredman	(def src-dir-filter (partial filter #(.endsWith (.getName %) "src")))
18:24	hiredman	(-> files-and-dirs jar-filter src-dir-filter)
18:24	hiredman	hmm
18:24	hiredman	that wouldn't work
18:25	bradford	i was wondering, in your first example using or...might there be another anonymous function to extract to avoid the cuplication?
18:25	bradford	the endswith getname stuff
18:25	hiredman	shrug
18:25	bradford	hehe
18:25	bradford	i'll jsut leave it as two seperate seqs :-)
18:27	Raynes	hiredman: Would you still love me if I learned Scala? :)
18:30	hiredman	be sure, I would not love you the less for doing such a thing
18:34	SethTisue	there are 12 of us on both #clojure and #scala
19:32	bradford	add-classpath at the repl is not working for me as it did earlier
19:32	bradford	(add-classpath "file:///home/bradford/opt/capjure/lib/java/hadoop-0.18.1-core.jar")
19:32	bradford	then ... (System/getProperty "java.class.path")
19:33	bradford	and that jar is not on the cp
19:33	bradford	any ideas?
19:33	hiredman	(System/getProperty "java.class.path") is never updated
19:34	hiredman	clojurebot: add-classpath
19:34	clojurebot	add-classpath is bad, avoid it. I mean it!
19:34	bradford	ok, what shall i use?
19:34	hiredman	java -cp
19:35	hiredman	clojurebot: jar directory
19:35	clojurebot	with java6(jdk1.6) CLASSPATH can contain a "" so /jar/dir/ will suck in all the jars in the /jar/dir directory, this also works with swank-clojure-extra-classpaths in emacs, alternatively you can use this shell snippet: find .jars/ -type f -name \*.jar -print0\|xargs -0\|sed "s/ /:/g"
19:36	bradford	i ahve been using the swank-clojure-extra-classpaths
19:37	bradford	but i building up a project with many dependencies...and trying to find a nice way to slurp up al the deps in various lib folders (jars) and esatablish deps on .cljs via the src dirs
19:39	hiredman	why bother connecting jars to individual source files?
19:39	bradford	so, sicne add-classpath is not working. what is a good hook for me to use so that I can create a clojure script that generates the list of paths that I want to feed to swank-clojure-extra-classpaths?
19:40	hiredman	just use the find command from above
19:40	hiredman	unless you are on windows, in which case find does something completely different
19:40	bradford	well, if i skip the add-classpath garbage, i don't need to collect jars sicne i can just add lib dris with lib/*
19:40	hiredman	and the classpath seperator is different
19:40	hiredman	correct
19:44	bradford	the issue is finding dirs containing jars to add lib/* to classpath and then finding dirs such as /src containing other clojure projects to add those paths to classpath to be able to use vars from those projects
19:45	bradford	I already have all the manual hackery in the my .emacs and bash scripts and stuff. but this is not really a great setup for maintaining a project aht dependens on many other clojure projects.
19:45	hiredman	I would jar up the other clojure projects
19:45	bradford	ah
19:45	hiredman	so you just have a set of jars
19:46	bradford	so assume that everything msut be jar'd
19:46	hiredman	well it lets you manage java and clojure in a uniform way
19:46	bradford	so then i just bring all projects under one dir my/project/deps ... jar them all up, and then something simpelr like find will be OK
19:46	bradford	good point
19:47	durka42	i see
19:48	bradford	and i should not need to use the find comamnd at all in that case?
19:48	bradford	will the lib/* work recrusively?
19:48	hiredman	I dunno
19:48	bradford	cool, i'll find out.
19:48	bradford	thx
19:54	hiredman	the "*" is not handled by shell globing but by java
21:13	redalastor	How can I do a GUI with a data entry zone and a rendering zone (data should asynchronously be rendered as typed).
21:14	redalastor	I thought of using an agent but I want the current rendering to be thrown out if it's not done and more data is typed. An agent would just queue all the intermediate stages.
21:15	arohner	redalastor: have you looked at atoms?
21:16	redalastor	I read about them but I didn't grok how they work.
21:18	arohner	they are a variable than can be set without race conditions
21:18	arohner	the new value is a function of the old value
21:18	arohner	but thinking about it, that isn't quite what you want
21:19	arohner	you sort of want agents, but you want new jobs to cancel in-progress jobs
21:19	redalastor	Exactly
21:20	Chouser	your in-progress jobs are going to have to poll to see if they should give up
21:20	redalastor	So somewhere in my rendering loop, I have to check if I should continue or not?
21:21	Chouser	Java doesn't like you cancelling threads from outside the thread, so I think your only option is from within the thread.
21:21	redalastor	Would there be a way to achieve what I want by storing a future in an agent?
21:22	Chouser	futures are for when you want something to block if it's not done computing yet
21:22	Chouser	I think some kind of reference type (perhaps an atom) to store the most-recent data value as entered by the user.
21:22	redalastor	Yes. But they return instantly so if I call an agent twice it will hapilly replace the first future with the second, right?
21:23	Chouser	you can put a watcher on that so that when the value changes it sends off an agent
21:23	arohner	you could use an atom or a ref to cancel in-progress rendering jobs
21:23	Chouser	that agent runs, occasionally checking its starting value with the current value of the atom
21:24	Chouser	if they don't match, return out of the agent, allowing the next watcher-sent agent in the queue to start over
21:25	redalastor	Makes sense. I was hoping there was a way to kill off a thread from outside itself.
21:25	Chouser	yeah, java doesn't like that
21:26	redalastor	According to Google, Java used to like it but it's deemed unsafe these days.
21:26	redalastor	http://java.sun.com/j2se/1.5.0/docs/guide/misc/threadPrimitiveDeprecation.html
21:27	dreish	Sounds like STM and immutable data structures would fix these problems.
21:29	redalastor	That's what I was thinking.
21:29	Chouser	fix the problems with halting a thread?
21:29	redalastor	With having damaged objects when you do.
21:30	Chouser	ah
21:30	dreish	I wouldn't trust it without a test running for tens or hundreds of hours, though.
21:30	Chouser	well, you could still have issues with exiting without going the finally blocks and such
21:34	Chouser	I do it every time I press Ctrl-C
21:34	dreish	gasp!
21:34	dreish	Wouldn't it be simpler to never make mistakes?
21:34	Chouser	hehe
21:35	dreish	I hold a code review meeting before hitting return, every time.
21:51	hiredman	must an issue clearing day
23:11	hiredman	~ticker IDSOX
23:11	clojurebot	IDSOX; +0.54
23:11	hiredman	:D
23:21	markgunnels	Not sure of the protocol but I have two Clojure questions I was hoping to get answered. I imagine they are rather simple but just non-obvious to a noob like myself.
23:23	markgunnels	If variables in Clojure are by default non mutable, why does this work:
23:23	markgunnels	(def favorite-books (list "Anathem" "Matter" "I know this much is true"))
23:24	markgunnels	(def new-favorite-books (cons "The Road" favorite-books))
23:24	markgunnels	Oops.
23:24	markgunnels	I mean (def favorite-books (cons "The Road" favorite-books))
23:24	markgunnels	It seems that I shouldn't be able to reuse the favorite-books variable.
23:24	arohner	markgunnels: vars can be re-defed to make development easier
23:25	arohner	you shouldn't do that in production
23:25	hiredman	it's usefull for swapping code in a running system
23:25	markgunnels	Ok. I know Erlang calls me on it.
23:25	markgunnels	So it surprised me when I got away with it.
23:26	markgunnels	Thanks.
23:26	arohner	np
23:27	hiredman	just do anything crazy like re-def'ing in a loop
23:27	markgunnels	Ok.
23:29	Chouser	don't
23:31	hiredman	good catch
23:31	cp2	heh
23:31	markgunnels	:-) I translated.
23:31	hiredman	~hiredman
23:31	clojurebot	hiredmans euler.clj is so embarassing
23:39	arohner	is there a way to find all existing refs?
23:40	arohner	when unit testing, I was thinking of a macro that would grab all refs, grab their value, execute body and then ref-set all of them back to their original value
23:40	hiredman	erm
23:41	hiredman	for why?
23:41	Chouser	arohner: I highly doubt it
23:41	arohner	so I don't have to worry about tests causing side-effects and interfering with each other
23:42	Chouser	arohner: you could find all vars in a namespace
23:42	arohner	from there, I could find all vars in all namespaces that are refs
23:42	arohner	hmm...
23:43	Chouser	but not any local refs
23:43	Chouser	or any refs only accessible via closures
23:43	arohner	yeah
23:48	slashus2	,(^ 5 2)
23:48	clojurebot	java.lang.NullPointerException
23:48	hiredman	,(pow 5 2)
23:48	clojurebot	java.lang.Exception: Unable to resolve symbol: pow in this context
23:48	hiredman	,(.pow 5 2)
23:48	clojurebot	java.lang.IllegalArgumentException: No matching method found: pow for class java.lang.Integer
23:49	slashus2	It is because ^ is a reader macro
23:49	slashus2	reader syntax
23:49	slashus2	,(Math/pow 5 2)
23:49	clojurebot	25.0