#clojure – 2011-03-13

2011-03-13

01:18	waxrose	>.>
01:19	scottj	I'm not very good at reading ascii art
01:21	waxrose	why's that?
01:23	scottj	lack of imagination I suppose
01:24	waxrose	What are you up to tonight?
01:25	scottj	was reading programming pearls first chapter (reduce (fn [bitmap n] (aset bitmap (dec n) 1) bitmap) (int-array 27000 0) file) then I got distracted by grooveshark
01:26	waxrose	I've never had a chance to read that one.
01:26	waxrose	Between class and doing every thing else.
01:30	scottj	reading's overrated
01:32	waxrose	how so?
01:33	waxrose	I find reading the only way to progress outside of pure experience.
01:34	scottj	I find reading uninspired by experience produces poor comprehension and short retention
01:35	scottj	I'm skeptical of the value of reading not motivated by problem solving
01:39	waxrose	mmhmm
01:40	waxrose	But then again, not every one reacts to stimulus the same way.
03:44	hiredman	~search for rhickey
08:42	pyr	hi
09:02	nawk	gud morning
09:24	raek	CompilerException java.lang.NoSuchMethodError: clojure.lang.RestFn.<init>(I)V (autodoc.clj:1)
09:24	raek	grrr
13:08	zoldar	,(do (defn pad [coll n x] (let [cnt (- n (count coll))] (if (pos? cnt) (concat coll (take cnt (repeat x))) coll))) (pad [1 2 3] 5 nil))
13:08	clojurebot	DENIED
13:08	zoldar	hmm, anyway, isn't such function already somewhere in core or contrib ?
13:10	david`	https://gist.github.com/868264
13:10	david`	:(
13:12	nickik	,((fn [coll n x] (let [cnt (- n (count coll))] (if (pos? cnt) (concat coll (take cnt (repeat x))) coll))) [1 2 3] 5 nil)
13:12	clojurebot	(1 2 3 nil nil)
13:13	MayDaniel	,((fn [coll n x] (take n (concat coll (repeat x)))) [1 2 3] 5 nil)
13:13	clojurebot	(1 2 3 nil nil)
13:13	zoldar	ah, nice
13:14	zoldar	david`, your (ns ..) form seems wrong to me. "use" instead of ":require" would probably work here
13:15	nickik	i edit de function in the irc. very lucky that i got all the parans right the first time.
13:16	david`	zoldar: thx!
13:16	TimMc	zoldar: ##(take 5 (concat [1 2 3] (repeat nil)))
13:16	sexpbot	⟹ (1 2 3 nil nil)
13:18	raek	david`: note that since 1.2 there is also clojure.string: (ns foo (:require [clojure.string :as str])) (str/replace ...)
13:18	zoldar	that just shows how my clojure-fu still sucks...
13:19	raek	though, some of the functions did not "make it" there
13:19	raek	or was renamed, so you'd have to read through the docs to see what's changed
13:19	raek	http://clojuredocs.org/clojure_core/clojure.string
13:29	joodie	...
14:00	avdi	I'm learning about metadata righ now, but "^" doesn't seem to be working. Has this changed?
14:01	joodie	Should work. Which version of clojure are you using?
14:02	spewn	&(let [x ^{:a 1 :b 2} [1 2 3]] (meta x))
14:02	sexpbot	⟹ nil
14:02	avdi	1.2
14:02	avdi	hmmm
14:02	spewn	Strange. That works for me with 1.2.0. What's wrong with sexpbot?
14:03	avdi	The Halloway book shows ^foo returning metadata for ^foo
14:03	joodie	works for me too @ 1.2
14:04	raek	avdi: this has indeed changed. since clojure 1.2, you have to use (meta ...) to extract the metadata
14:05	avdi	raek: gotcha, that explains it.
14:05	avdi	raek: thanks
14:05	raek	avdi: and ^ is the new reader syntax for adding metadta (#^ still works, though, but should be avoided for future compability)
14:05	joodie	and since 1.2 you can use ^{ ... } to set metadata
14:06	joodie	If you want the details of these sort of short-hands, look at the reader docs: http://clojure.org/reader
14:06	raek	also, with-meta is the function you'd use in you program (^ only adds metadata to the code literal)
14:07	avdi	raek: I'm going to have to think about that last statement for a bit
14:10	raek	if the evaluator sees a collection literal with metadata on it, it will evaluate the contents and make a new data structure of the same kind. the metadata map will also be evaluated. then, the evaled metadata will be attached to the new data structure
14:10	raek	,(let [x 1] (meta ^{:foo x} [1 x 3]))
14:10	clojurebot	{:foo 1}
14:11	raek	but
14:11	raek	,(let [x 1] (meta ^{:foo x} (list 1 x 3)))
14:11	clojurebot	nil
14:12	raek	(list ...) is not a data literal, so the metadata on the code won't be attached to the result
14:12	raek	,(let [x 1] (meta (with-meta (list 1 x 3) {:foo x})))
14:12	clojurebot	{:foo 1}
14:13	raek	,(let [x 1] (meta (with-meta [1 x 3] {:foo x})))
14:13	clojurebot	{:foo 1}
14:14	avdi	In the first (list) example, what exactly is the metadata attached to?
14:14	avdi	the list form?
14:15	joodie	could be
14:15	raek	it's attached to the list whose elements are the symbol "list", the number 1, the symbol "x" adn the number 2
14:15	raek	*3
14:15	avdi	raek: gotcha. Makes sense.
14:16	raek	that is, the thing that is sent to the compiler
14:17	raek	so, symbols and list have special behaviour for metadata, just as they have special behaviour for evaluation in general
15:42	angerman	how do i get c.c.string/join to not return LazySeq@… ?
15:43	angerman	I hoped, doall would do… but doesn.
15:43	fliebel	angerman: apply str?
15:44	angerman	fliebel: ?
15:44	amalloy	angerman: ##(str (range))
15:45	sexpbot	Execution Timed Out!
15:45	amalloy	angerman: ##(str (range 2))
15:45	sexpbot	⟹ "clojure.lang.LazySeq@3c2"
15:45	fliebel	&(apply str (reng 5))
15:45	sexpbot	java.lang.Exception: Unable to resolve symbol: reng in this context
15:45	amalloy	&(apply str (range 2))
15:45	sexpbot	⟹ "01"
15:45	fliebel	&(apply str (range 5))
15:45	sexpbot	⟹ "01234"
15:45	fliebel	right, finally
15:45	amalloy	string/join is the same, iirc - it wants multiple params, not a single coll
15:46	amalloy	so if you have a coll you should be able to apply it
15:46	raek	angerman: you can use pr-str to turn clojure data structures into strings
15:46	raek	*a string
15:46	amalloy	,(pr-str (promise))
15:46	clojurebot	Execution Timed Out
15:46	amalloy	raek: not entirely true :P ^
15:47	fliebel	&(pr-str [1 2 3])
15:47	sexpbot	⟹ "[1 2 3]"
15:47	raek	I don't know if I would call a promise a data structure
15:48	raek	,((juxt str pr-str) (range 5))
15:48	clojurebot	["clojure.lang.LazySeq@1b554e1" "(0 1 2 3 4)"]
15:48	angerman	what for is clojure.string/join?
15:48	angerman	so I tried to write code according to clojure.string/join whil eusing c.c.string/join. ouch.
15:49	raek	clojure.string/join takes a seq of strings as its input (if the elements are not strings they will probably be converted with 'str')
15:50	raek	so if you want to turn the elements into strings in some other way (e.g. pr-str) you should (map pr-str ...) them first
15:50	angerman	no. I actually wanted to use "join" because I wanted the seperator.
15:51	raek	yes, but the stuff you want to join with the separator must be a seq of strings
15:52	angerman	reak, yes, that's what I get from (format…)
15:52	amalloy	&(use '[clojure.string :only [join]])
15:52	sexpbot	⟹ nil
15:52	amalloy	&(join "," (range 5))
15:52	sexpbot	⟹ "0,1,2,3,4"
15:52	angerman	the problem was that i tried (join coll sep) instead of (join sep coll)
15:52	raek	format will also call str on its arguments
15:52	raek	ah
15:53	angerman	&(doc clojure.string/join)
15:53	sexpbot	⟹ "([coll] [separator [x & more]]); Returns a string of all elements in coll, separated by an optional separator. Like Perl's join."
15:53	angerman	&(doc clojure.contrib.string/join)
15:53	sexpbot	⟹ "([separator coll]); Returns a string of all elements in coll, separated by separator. Like Perl's join."
15:53	angerman	that is plain weird!
15:53	amalloy	angerman: you're just misreading the arglists
15:53	amalloy	both of them take sep coll
15:54	angerman	amalloy: ahh, multi arity
15:54	angerman	dang.
15:54	amalloy	indeed
16:39	User	hey
16:39	jaley	hi guys - can anyone offer me some best-practice advice wrt wrapping up java APIs and mocking?
16:39	User	anyone familiar with Enlive?
16:41	jaley	I'm using java api generated by apache axis to talk to some servers with soap. I think for test purposes I'd like to mock out the real function calls with c.c.mock, but clearly I can't use binding to mock out a java method call. Is this an acceptable time to break idioms and wrap the java API with clojure function calls? Or would another approach altogether be better maybe?
16:43	User	what does the soap client look like
16:43	User	I generally extend the soap client with a class of my own
16:44	jaley	@User ; (.getEvents service)
16:44	jaley	where service is a java object, code generated by axis
16:47	anthony	I'm working with a datastore, which has an int field representing an enum. In Clojure, I need to translate these ints to/from keywords (with hard-coded associations). What's the cleanest way to do this? I've had a map like asc = {0 :start 1 :inprogress 2 :end}, which allows me to do (asc 1) to get a value from a key, but how about the other way around (given a value, find the key)?
16:48	User	make a java class with public static final variables then refer to it as class/CONSTANT
16:48	User	trollface
16:49	amalloy	&(clojure.walk/walk reverse hash-map {0 :start 1 :inprogress 2 :end})
16:49	sexpbot	java.lang.ClassCastException: clojure.lang.Keyword cannot be cast to java.util.Map$Entry
16:49	amalloy	booo
16:49	raek	I would use two maps. maybe initialize them from the same data
16:49	amalloy	&(clojure.walk/walk (comp vec reverse) hash-map {0 :start 1 :inprogress 2 :end})
16:49	sexpbot	java.lang.IllegalArgumentException: No value supplied for key: {:start 0, :inprogress 1, :end 2}
16:49	anthony	Is there an easy way to "flip" a map? Or should I store the data a different way, then create maps out of it (like an even-length vector?)?
16:50	amalloy	ugh, whatever
16:50	amalloy	anthony: there are a number of ways to flip a map. the one that requires the least thinking for me is ##(into {} (for [[k v] {0 :start 1 :inprogress 2 :end}] [v k]))
16:50	sexpbot	⟹ {:start 0, :inprogress 1, :end 2}
16:51	anthony	amalloy: Awesome. That works perfectly. Thanks a ton.
16:51	amalloy	i was trying to use walk because it's cleaner, but i was doing it wrong :P
16:51	amalloy	&(clojure.walk/walk (comp vec reverse) identity {0 :start 1 :inprogress 2 :end})
16:51	sexpbot	⟹ {:start 0, :inprogress 1, :end 2}
16:51	phenom_	anyone know how to fix indentation in amcs when declaring deftypes with multiple protocols ?
16:51	amalloy	there
16:51	sattvik	,(let [m {0 :a 1 :b}] (zipmap (vals m) (keys m)))
16:51	anthony	Even better.
16:51	clojurebot	{:b 1, :a 0}
16:51	amalloy	sattvik: ##(apply zipmap ((juxt vals keys) {0 :a 1 :b}))
16:51	sexpbot	⟹ {:b 1, :a 0}
16:52	raek	,(into {} (map (juxt val key) {:a 1, :b 2}))
16:52	clojurebot	{1 :a, 2 :b}
16:52	jaley	oh my, so many ways to skin that cat?
16:52	amalloy	ah, score one for raek, i think
16:52	anthony	haha dangit, now I have too many options to pick from. :-)
16:52	raek	phenom_: in emasc?
16:52	raek	*emacs
16:52	anthony	I like the juxt one, though. Thanks for all the help, amalloy and raek
16:54	User	I came upon the following code when looking at enlive:
16:54	User	(transformation [:.text] (content item) {[:input][:br]} (clone-for [x choices]
16:54	phenom_	raek: yea
16:55	User	what kind of selector is {[:input][:br]}
16:55	User	I thought selector had to be a vector
16:55	raek	phenom_: you can use M-x customize-variable, clojure-mode-use-backtracking-indent
16:55	amalloy	User: that doesn't look like a selector to me
16:55	phenom_	raek: http://pastie.org/1667951
16:55	jaley	@User from memory, can a selector not also be a function?
16:56	brehaut	User: enlive uses a map as a range selector for some things
16:56	raek	phenom_: yes, enabling backtracking indent makes that indent correctly
16:57	phenom_	raek: perfect, thnx
16:57	amalloy	maps...as range selectors? gross
16:58	User	I have no idea what that is
16:58	User	http://groups.google.com/group/enlive-clj/browse_thread/thread/45e0e64f51ec6bdb?pli=1
16:58	User	look at cgrand's answer
16:58	User	first code snippet
16:59	brehaut	User: {:input :br} selects (inclusively) everything between an input and br
16:59	User	oh
16:59	User	intredasting
17:01	brehaut	amalloy: why is maps as ranges bad?
17:03	amalloy	brehaut: it clashes conceptually with the notion of key=>value; he's just using it to store a pair. if [[:input][:br]] isn't used for anything else i'd like it better
17:03	brehaut	i think it is used
17:04	amalloy	i imagine so
17:04	amalloy	otherwise he'd use it here :)
17:04	brehaut	indeed :P
17:07	User	what's [[:input][:br]] used for ?
17:10	brehaut	[[#{:ul :ol} :.outline] :> :li] ul.outline > li, ol.outline > li
17:10	brehaut	thats from the readme
17:10	brehaut	under 'syntax'
17:11	brehaut	roughly parenthisis basicly (which CSS doesnt have)
17:13	User	so set is used for OR
17:13	User	and vector is and
17:14	TimMc	amalloy: Yeah, I was cringing when I saw that in his (not= DSL macros) talk
17:14	brehaut	its not and, its grouping
17:14	User	it has to match both selectors in the inner vector
17:14	brehaut	s/grouping/parenthsis
17:14	sexpbot	<brehaut> its not and, its parenthsis
17:14	User	does it not?
17:15	User	what the hell is parenthesis
17:15	amalloy	lol
17:15	brehaut	well yes, but not in an and way
17:15	User	parenthesis is a character
17:15	brehaut	(1 + 2) * 3
17:15	brehaut	parenthsis
17:15	User	I read it as such
17:16	brehaut	it makes that subselector atomic to the operators that contain it
17:16	TimMc	parentheses
17:17	User	ok so if I have this selector [:ul :.outline] it will select all elements that are ul tag and outline style
17:17	brehaut	TimMc: sorry
17:17	User	because I always thought that would select an element with outline style that is a child of ul element
17:18	brehaut	User: no, it will select all elements with the "outline" class that are inside a ul element
17:18	brehaut	wait, i think you might be right in that case
17:18	joshua__	Is there a Clojure library out there for converting HTML to Markdown. I've been trying to do it with an XSLT and Saxon, but I've been having a bit of trouble.
17:18	brehaut	hah excuse me for being a complete arse
17:19	brehaut	but i think you are right that it is actually an and in this case
17:20	User	that's what confused me immensely
17:21	User	the outermost vector is processed differently than any inner vectors
17:21	brehaut	yeah you are right
17:21	amalloy	brehaut: you forgot to pretend you prefer tea
17:21	User	off to my REPL
17:21	User	got to test this
17:22	brehaut	amalloy: oh crap
17:22	brehaut	User: good plan
17:25	User	http://pastebin.com/5AfExvj5
17:25	User	look at this
17:26	User	the difference between [:ul :.content] [:body :.content] and [[:ul :.content]]
17:26	User	or lack there-of
17:30	brehaut	TimMc: well done :)
17:30	tufflax	I don't like that clojurebot uses notice for that :P
17:31	TimMc	brehaut: Thanks!
17:33	brehaut	User: that does appear surprising
17:34	amalloy	tufflax: what would you prefer?
17:35	tufflax	Normal message maybe. The thing is that it makes a sound, which I turned off now, but it's handy to have that sound if someone needs to reach me
17:36	TimMc	Is it a new feature?
17:38	amalloy	tufflax: that's a weird thing for your client to do
17:38	amalloy	notices are supposed to be lower-impact than regular messages, not higher
17:38	tufflax	oh, is that so :P
17:39	tufflax	WHat's supposed to be higher then?
17:39	Derander	amalloy: textual makes them show up with a red background and red text
17:41	amalloy	The NOTICE message is used similarly to PRIVMSG. The difference between NOTICE and PRIVMSG is that automatic replies must never be sent in response to a NOTICE message.
17:43	Raynes	amalloy: I'd use notice for that as well assuming we had a similar feature in sexpbot.
17:43	amalloy	Raynes: github commits?
17:43	brehaut	whoa, raynes has taken time out from trying android apps to visit irc!?
17:43	Raynes	Ghats
17:44	Raynes	brehaut: I'm actually just on my phone.
17:44	tufflax	amalloy: I don't think it clear from that that notices are lower-impact than regular messages. But, anyway, it's not a big problem :)
17:45	Raynes	amalloy: That's a ripoff of someone else's bot. Never occurred to me to use notices for that.
17:45	Raynes	A more sophisticated ripoff, but a ripoff nonetheless.
17:46	Raynes	Brb, getting on the desktop.
17:46	amalloy	tufflax: agreed, that in itself is insufficient to show that notices are lower-impact. but i think it does demonstrate that they shouldn't be higher impact
17:49	tufflax	amalloy: Yeah, perhaps. Thank you for making me aware :)
17:50	Raynes	Back.
17:51	Raynes	amalloy: Don't we have a contributor list that isn't on my blog? Like, in the README?
17:51	Raynes	If so, we should add brehaut to that. I never intended to edit that blog post every time someone committed to sexpbot.
17:52	Raynes	I'll check and do that in a moment. Got to get my environment going.
17:56	Raynes	brehaut: But yes, Android is awesome. :>
17:56	brehaut	ha
18:01	nickik	What does this mean in java
18:01	nickik	int iterations = 1 << (maxDepth - depth + minDepth);
18:02	amalloy	<< is left-bit-shift
18:02	User	it's a retarded shift trick
18:02	User	It basically says 2^(maxdepth-depth + mindepth)
18:02	brehaut	looks liek someone is trying to (perhaps naively) optimize multiplication
18:03	nickik	i doing a benchmark
18:03	amalloy	tbh i can't imagine why you'd want to add max+min depths together, and subtract some other depth
18:03	nickik	im
18:03	User	it might make it faster but unless this is rolling in a loop like crazy
18:03	User	it's not worth the obfuscation
18:04	raek	it's like when people write x >> 1 instead of x / 2
18:04	User	yeah
18:04	brehaut	it also makes assumptions about the compiler(s)
18:04	nickik	http://shootout.alioth.debian.org/u64/program.php?test=binarytrees&lang=java&id=2
18:05	amalloy	wow, it's been a while since i saw such unanimous unbridled hate for shift operators
18:05	User	not worth it in this case
18:05	brehaut	amalloy: ha
18:05	nickik	how should I writ it in clojure?
18:06	User	the cost of other things in the outer loop is many many many times bigger than the difference between bitshift and multiplication
18:06	Raynes	brehaut: I just wrote a contributor section into the sexpbot readme and put you in it. Congratulations in becoming an honorary sexpbot contributor. You win a brand new internet!
18:06	brehaut	Raynes: cheers :)
18:06	brehaut	its trying hard to be the least used contribution too :P
18:07	User	(bit-shift-left 1 (- maxDepth (+ depth minDepth)))
18:08	Raynes	brehaut: It's a sneaky little thing that nobody would ever care about until it actually works for them and then they love it.
18:08	brehaut	thats the plan
18:08	amalloy	yeah
18:14	User	interesting page nickik
18:14	nickik	page?
18:14	spewn	&(+ 1 2 3
18:14	User	clojure is quite slow especially when problem size isn't huge
18:14	sexpbot	⟹ 6 ; Adjusted to (+ 1 2 3)
18:14	spewn	I love it!
18:14	phenom_	anyone have cake working with clojure 1.3 ?
18:14	User	the shootout nickik
18:15	phenom_	[org.clojure/clojure "1.3.0-master-SNAPSHOT"] as a dependency isn't working for me in project.clj
18:15	nickik	User, yeah im doing a project for school and i want to have the binarytree working with 1.3 alpha
18:15	User	for huge huge problem size of 2^20 it's only 3 times slower than java but for 2^12 which is a huge binary tree nonetheless it's like 15 times slower than java
18:16	User	(most of my programs use lists and vectors of size around 10 and there clojure is around 40 times slower than java)
18:21	User	wow for binary trees of size 4096 nodes, clojure is the slowest language
18:21	nickik	Mhh the bitshift does not seam to work with longs
18:22	nickik	call to shiftLeft can't be resolved.
18:22	nickik	(its a reflection warning)
18:23	nickik	User, why do you think that is?
18:23	User	yeah and that code uses unchecked ops everywhere
18:24	User	no idea
18:24	User	immutable data and checked arithmetrics are usually the biggest slowness
18:24	User	notice that lisp does much better
18:25	raek	boxing is very bad for performance too
18:25	User	because it allows mutation and it uses imperative programming
18:25	User	yes
18:25	User	this code uses (int x) and such a lot though
18:25	User	http://shootout.alioth.debian.org/u64/benchmark.php?test=binarytrees&lang=clojure
18:26	nickik	in 1.2 you cant box if you have a function call right?
18:26	User	I don't see how it can be improved
18:26	nickik	her is my take: https://github.com/nickik/IDPA-Programmiersprachen-Benchmarken/blob/master/clojure/src/clojure/binarytrees_me.clj
18:26	User	I mean even LUA is faster :D
18:26	User	and python :P
18:27	raek	nickik: you can't pass primitives over function boundaries, yes
18:27	raek	...in 1.2
18:27	User	and erlang
18:27	User	and ruby :D
18:28	nickik	reak, the version i linked is 1.3
18:28	User	seems to me that JVM also limits clojure performance in some ways, it just wasn't made for this
18:28	nickik	that should speed things up
18:28	User	LISP compilers have free hands
18:28	nickik	the code for this example is almost one to one translation from java
18:29	User	I know
18:29	User	it's quite non-idiomatic too
18:30	User	nobody actually writes clojure like that imo
18:30	nickik	does not matter its a benchmark
18:31	nickik	Was a stupid idea to use benchmarking for a school project
18:31	nickik	its way to hard and does not look impressiv
18:32	User	indeed
18:32	User	I'm just saying, it's an annoying thing with clojure
18:32	nickik	should of just have implemented some parallel code in clojure and java and show how clojure is better
18:32	User	you have to write differently than normal if you don't want some huge performance hits
18:33	User	in java I just write normal code and it usually doesn't run much slower than hand optimized
18:33	User	with clojure difference is quite significant
18:34	User	with all those unchecked-add, I think it woudl be easier to just rebind + to unchecked-add :P
18:34	nickik	2^(maxdepth-depth + mindepth) should work to right, then i could throw away bit-shift
18:35	nickik	whats the function for 2^ in clojure?
18:35	User	bit shift is quite a bit faster than power
18:35	nickik	but it needs to use reflection
18:35	User	clojure generally uses Math/pow from java
18:35	User	for all you power needs
18:36	nickik	i have to find out whats faster later
18:36	User	or (apply * (repeat 2 n))
18:36	amalloy	clojure.math/expt
18:36	User	both are slot :D
18:36	User	slow
18:36	clojurebot	Gabh mo leithscéal?
18:36	amalloy	User: i disagree with your claim about map/pow
18:36	amalloy	s/map/Math
18:36	sexpbot	<amalloy> User: i disagree with your claim about Math/pow
18:37	User	why
18:37	amalloy	it only deals with Double, and for example there's clojure.math/expt that handles all of clojure's numeric data types
18:38	User	yeah well in any case any implementation does as many multiplications as the exponent is
18:38	User	while bitshift is like a single add
18:39	amalloy	User: half an hour ago you were telling everyone that << wasn't worth the obfuscation
18:39	User	generally
18:40	User	in any case it's unfortunate that default numeric data in clojure is that slow...considering 99% of the time I modify numeric data it's "count++" type of code and the variable is well inside int range
18:41	User	thus I rarely get to use the benefits (automatic promotion of type)
18:41	brehaut	User: really? you increment counters a lot in your clojure code?
18:41	amalloy	hah, good catch there brehaut
18:41	User	not that much
18:42	User	usually when I use recur
18:42	User	but it sure comes up more often than anything else
18:42	User	any other numeric manipulation
18:42	amalloy	User: i rarely wind up needing to use recur either. just let the lazy seqs flow
18:43	amalloy	less performant but more reusable
18:43	User	and how do you generate these seqs
18:43	amalloy	and more readable
18:43	User	usually there's some variable that changes
18:43	brehaut	&(apropos "-indexed")
18:43	sexpbot	java.lang.Exception: Unable to resolve symbol: apropos in this context
18:43	brehaut	&(use 'clojure.repl)
18:43	sexpbot	⟹ nil
18:43	amalloy	map-indexed
18:43	User	in any case it's SLOOOOOW
18:43	brehaut	&(apropos "-indexed")
18:43	sexpbot	⟹ (keep-indexed map-indexed)
18:44	User	that just hides inc calls
18:44	amalloy	but brehaut, those use lazy seqs under the covers. it's so slow!
18:44	User	they still happen and they are still slow
18:44	amalloy	User: actually it's using (range), bet you a million dollars. (range hides the incs, of course)
18:44	User	:D:D:D:D
18:44	User	always comes down to inc :D
18:45	tomoj	don't bet
18:45	User	s/inc/inc calls/
18:45	sexpbot	<User> always comes down to inc calls :D
18:45	tomoj	neither use range in 1.2
18:45	amalloy	tomoj: if i'm wrong i'll just claim by "dollars" i meant something else
18:45	tomoj	ok :)
18:45	brehaut	tomoj: they do use primative ints for counters though
18:46	brehaut	(which is to say: agreeing)
18:46	phenom_	,(deftype Test [] clojure.lang.IPersistentVector (length [this]))
18:46	tomoj	really? I dno't see that
18:46	clojurebot	sandbox.Test
18:46	phenom_	,(Test.)
18:46	clojurebot	#<ExecutionException java.util.concurrent.ExecutionException: java.lang.AbstractMethodError>
18:46	brehaut	'size (int (count c))" hmm, maybe just for the size
18:47	tomoj	I see a letfn with lazy-seq that calls itself
18:47	tomoj	in 1.2 I don't see how this could possibly be primitive
18:47	brehaut	the inner most let
18:47	tomoj	ah, right
18:48	brehaut	it would boxed up again though wouldnt it
18:50	User	I doubt core functions use primitive ints for anything
18:50	User	because most of those functions are supposed to work for infinite sequences and stuff like that
18:51	User	in any case look at that language shootout page
18:51	brehaut	i see no reason that there could not be a polymorphic implementation that uses primatives till it overflows and then slowints to the rest of infinity
18:52	User	even though clojure beats a lot of languages such as ruby, lua and stuff at binary trees with size of 1 mil, it's the slowest language with small trees size 4000, which is majority of data
18:52	User	I ever use
18:52	tomoj	slower than ruby is hard to believe
18:54	User	look at it yourself
18:54	dnolen	User: JVM startup time.
18:54	tomoj	I don't mean that I don't believe those are the current results, I mean that those results aren't _right_ :)
18:56	dnolen	User: has nothing to do w/ small trees. A warm JVM will be eat Python and Ruby for breakfast.
18:56	User	I think jvm startup time doesn't count
18:56	User	look at java stats
18:56	User	it beats most languages
18:56	User	clojure none
18:56	ossareh	morning 'all
18:57	ossareh	s/'//
18:57	sexpbot	<ossareh> morning all
18:57	dnolen	User: I don't know the details of how those example are run, if they are AOT etc. Doesn't matter, Clojure is not slow on small trees, makes no sense.
18:57	tomoj	saying "java beats most languages" or "clojure beats none" seems a bit misleading. as if the results give facts about the languages
18:58	ossareh	clojure beats everything I've ever used in terms of expressiveness.
18:58	tomoj	that in this example clojure loses to ruby suggests very strongly to me that these results aren't about the language at all
18:59	User	see tomoj you are arguing with no data either
18:59	User	against what you call flawed data
19:00	brehaut	one sample point is not a basis for an argument either
19:00	User	from dropdown you can select other samples
19:00	joshua__	link to what your talking about
19:00	joshua__	?
19:00	User	but that's beside the point
19:01	User	joshua__: http://shootout.alioth.debian.org/u64/benchmark.php?test=binarytrees&lang=clojure
19:01	tomoj	presumably running with the larger tree sizes gives larger runtimes
19:01	User	it does
19:01	tomoj	I wonder if that is the only way the jvm startup time becomes less dominant, and the only way hotspot is allowed to wake up?
19:02	User	no idea
19:02	tomoj	still, slower than ruby baffles me unless the runtime for that size is very short
19:02	User	in any case you can compare java and clojure if you want
19:02	User	my java code is usually 3 - 200 times faster
19:02	User	most often in 10-40 range
19:04	User	this usually comes from ArrayList - clojure vector difference and arithmetics
19:06	joshua__	http://shootout.alioth.debian.org/u64/performance.php?test=binarytrees&sort=elapsed
19:06	joshua__	isn't that saying Clojure is ahead, not behind? Or am I missing something?
19:07	dnolen	User: not surprising. Writing fast Clojure takes some experience. Clojure generates a lot of classes, even w/ AOT I imagine that adversely affects startup time.
19:08	nickik	Ah it works know with 1.3, know i only have to find out if its going to be fast than 1.2
19:09	amalloy	joshua__: you must be reading it wrong
19:09	mec	my paredit has quit working. It was working perfectly yesterday, and I havn't changed anything since. Anyone know what might be wrong, or how to find out?
19:10	User	joshua__ that is N=20 --> million elements tree, try N=12 4000 elements tree
19:10	tomoj	mec: elaborate?
19:10	User	dnolen: saying that writing fast programs reuqires special knowledge doesn't do it any favors
19:11	mec	tomoj: the commands to move parenthesis around do nothing, and while typing ( produces () deleting the opening parenthesis does not remove the closing one at the repl. In a *.clj file it doesnt appear to work at all
19:12	amalloy	mec: the repl is generally not in paredit mode. mine isn't, anyway
19:12	tomoj	mec: and you still see "Paredit" in the modeline for a clj file?
19:12	dnolen	User: eh? that's the case for pretty much every PL I ever used for any non-trivial program.
19:12	mec	tomoj: no, there is a Paredit on the repl line
19:13	tomoj	I'd be surprised if that didn't cause trouble
19:13	tomoj	but if you don't see it in the modeline for a clj file, it's not on
19:13	dnolen	User: in fact, Alioth benchmarks is proof of that.
19:14	mec	tomoj: the lines are still in my .emacs to enable it
19:14	tomoj	a clojure-mode-hook?
19:14	brehaut	dnolen: you can write fast small programs in c without specialist knowledge
19:15	amalloy	i set my repl to use paredit mode once. it was a disaster, for reasons i don't remember
19:15	dnolen	brehaut: non-trivial means moving memory around, then you have start getting clever.
19:15	mec	it looks like it adds it to anything that is a -mode-hook and specifically after that to slime-repl-mode-hook
19:15	brehaut	dnolen: sure, it gets hard very fast
19:16	ldh	any compojure folks? i'm trying to set the content-type header in my handler response. I've seen it documented like this, but I get "unsuppored binding form: :headers
19:16	ldh	(GET "/" [{:headers {"Content-type" "text/plain"}} "Response text"]
19:16	tomoj	clj files aren't in slime-repl-mode
19:16	tomoj	and I don't think you want paredit turning on in every mode hook...
19:16	mec	oh sorry its just '(emacs-lisp lisp inferior-lisp slime)
19:16	tomoj	perhaps you should add clojure? ..do you use clojure-mode?
19:17	mec	yes let me add it and see if that fixes it
19:17	nickik	https://github.com/nickik/IDPA-Programmiersprachen-Benchmarken/blob/master/clojure/src/clojure/binarytrees_me.clj
19:18	brehaut	ldh: you might find #compojure more helpful?
19:18	nickik	Can somebody help me I keep getting "Exception in thread "main" clojure.lang.ArityException: Wrong number of args (2) passed to: core$number-QMARK-"
19:18	ldh	brehaut: ah, of course. thanks.
19:18	brehaut	ldh: sorry i cant help more, i mainly use moustache
19:18	mec	I get a "File mode specification error: (error "Unmatched bracket or quote")" when I open a .clj, could that be the case?
19:18	mec	r/case/cause/
19:19	User	dnolen: I can do very fast java programs without any special care
19:19	nickik	Hard to understand whats going on if you don't even get a linenumber.
19:19	tomoj	mec: you lost me, sorry. good luck
19:20	dnolen	User: would you say your Java knowledge is about equal to your Clojure knowledge?
19:20	tomoj	amalloy:
19:21	ldh	brehaut: no worries. a bit of struggle is part of the process of learning a new language/paradigm I suppose ;)
19:21	tomoj	er. amalloy: I heard durendal can make paredit work in the repl. haven't tried it yet
19:21	brehaut	ldh: perceiver though, clojure's web ecosystem is developing very nicely
19:22	nickik	dnolen, i think its true because in java you mostly just use plain old imperativ code witch is just fast than in clojure (plus its mutch easier to get primitv types working)
19:22	ldh	brehaut: indeed. seems like a pretty exciting time to be writing webapps in clojure
19:22	brehaut	ldh: definately is
19:23	User	dnolen: no, but in java I at least don't need to change operators in every function and wrap all in additional casts to get performance
19:24	tomoj	nickik: condp passes two args to each pred, number? and string? take only one arg
19:25	tomoj	er, ignore that
19:25	tomoj	but that's where your problem is :)
19:25	User	here's java optimization: unroll a loop somewhere, take a calculated variable and take it out of a loop
19:26	dnolen	User: I'm certainly not saying all in the Clojure world is wine and roses. < I agree 1.2 required too much expertise. Those are known pain points - 1.3.0 addresses some of the more problematic one.
19:26	joshua__	I just tried to implement a html to markdown converter. My attempt can be seen here: https://gist.github.com/868546 It was created by trying to translate this SO answer to Clojure: http://stackoverflow.com/questions/59557/html-to-markdown-with-java
19:26	User	here's clojure optimization: every trick of java optimization PLUS you need to replace all calls to * + - etc with unchecked, all numeric variables with (int x) and arguments with type hints
19:26	joshua__	It doesn't work. I don't know enough about what I'm doing to know why.
19:26	User	a LOT more work, also makes code super ugly
19:27	dnolen	User: and it would great for higher order operations to work on collections of Java primitives. Work is being done on this stuff.
19:28	nickik	you can rebind unckecked-math or something to avoid the hole unckecked stuff right? (in 1.3)
19:28	tomoj	nickik: right, so it's evaluating (apply number? args). I guess you're passing two args?
19:29	tomoj	..those will never be numbers anyway, will they?
19:30	nickik	tomoj, true i will replace it with something else
19:31	mec	wow so apparently an errant close paren somewhere in the source killed Paredit from loading at all
19:33	nickik	tomoj, i dont think its that. I use the same -main in a other namespace and it works there
19:33	tomoj	there, how many args do you pass?
19:34	Derander	serial-port is relevant to my interests
19:34	dnolen	User: for a lang that's three years old to be butting up against CL and Racket on Alioth is remarkable, I have high hopes for continued improvements to Clojure performance and regaining some lost expressivity.
19:35	nickik	tomoj, only one.
19:35	tomoj	nickik: gotta go. if you're passing one arg to that one, and two args here, maybe you can see the problem?
19:37	User	what expressivity was lost?
19:38	User	dnolen:scala isn't any older (I think?) and is 3 times faster
19:39	amalloy	ugh. unless you have to write any code in scala. that should slow you down
19:39	dnolen	User: Scala is 2003.
19:39	brehaut	Scala is much older than clojure: wikipedia lists its first appearance as 2003
19:39	Derander	doesn't clojure also stand to gain massively from java 7?
19:40	dnolen	Derander: I don't think so.
19:40	nickik	mmh not really
19:40	Derander	okay
19:40	Derander	nevermind then :-)
19:40	nickik	maybe a little but not like ruby
19:40	amalloy_	Derander: it looks that way to me, but people who know better than i say no
19:40	User	besides clojure isn't butting up to CL and Racket for small lists
19:40	Derander	okay. I'm also watching from a ruby perspective so perhaps I crossed the channels
19:40	nickik	the forkjoin stuff and the closures will be helpfull
19:41	dnolen	User: Alioth doesn't bench small lists in long running programs.
19:47	User	4000 elements is still quite big
19:48	User	try putting 10 elements into a vector...then 10 elements into an arraylist, then run this in a million iteration loop, so hotspot isn;t an issue
19:48	User	staggering difference
19:49	nickik	dnolen, did you look into that logic programming language you mention on your blog (that so much faster then prolog). I didn't have time to look into.
19:54	dnolen	User: Try changing an ArrayList and getting the old version of the ArrayList before the change. staggering difference. Anyways sorry but this conversation isn't going anywhere for me.
19:54	dnolen	nickik: ? what are you referring to?
19:56	nickik	dnolen, The Mercury Programming Language
19:59	dnolen	nickik: I've only looked into it a little. Seems interesting, performance is very impressive. Lack of REPL is a turnoff for me tho.
20:12	amalloy	technomancy: that is an adorable thing for your kid to do
20:13	User	I knew you;'d say that
20:15	User	too bad immutability doesn't do anything when vector doesn't leave the fn
20:34	fliebel	dnolen: Which of your posts mentions Mercury? I think that paper you sent me also mentions it.
20:34	dnolen	fliebel: I only mentioned it in passing as something interesting to look at. Enjoying the paper?
20:36	fliebel	dnolen: So far… meh. It contains a lot of stuff I already read in TRS, but I assume it's only the beginning, and even there it has a few interesting insights.
20:38	dnolen	fliebel: yeah it picks up when it covers the implementation.
20:38	fliebel	I skipped forward to the arithmetic part, and they explained why it is so much more complicated that one would think at first, thinking of it as a recursive full-adder. They stress determinism(is that a valid word?) much more than the book.
20:40	fliebel	I think they mentioned Mercury for its ability to use regular functions in unifications, deferring their action untill all values are grounded, but deny this approach because it can not be said to terminate.
20:40	fliebel	This is kind of what project does, right?
20:43	dnolen	fliebel: project is for getting a logic vars value so you can use regular (non-relational) operations on them. For example you might know that a logic var is bound to a Clojure set, and you really just want to use conj etc on it's value.
20:45	fliebel	dnolen: Oh, yea, I mixed up a few terms, I need to sleep. See ya.
20:47	brehaut	dnolen: is project equiv to m-lift for logos ?
20:48	dnolen	brehaut: sadly my monad fu is significantly less than my logic fu, and honestly both are quite low :) what does m-lift do? lift a value out of a monad?
20:48	brehaut	it lifts a function into the monad
20:49	dnolen	brehaut: ah, it takes a regular function and allows it be used w/in a monad?
20:49	brehaut	yeah thats a better way of putting it
20:54	brehaut	my monad fu is pretty low too, but im interested in the correspondence between alternative models of evaluation and the monadic operations
20:54	dnolen	interesting, it does sound related. But the issue is different. Many useful operations are hard (impossible?) to define efficiently in a relational way (where inputs/outputs are interchangeable). So instead of struggling to define everything relationally, project is bit of an escape hatch for solving common problems with the downside that you can no longer infer inputs from outputs.
20:55	brehaut	ah right
20:56	brehaut	that input/output interchangability is where ive hit a roadblock trying to slowly evolve a logical variation of the monkey and banana from a naive functional variation
20:57	dnolen	brehaut: in Prolog?
20:57	brehaut	in clojure
20:58	brehaut	taken from the bratko book
20:58	brehaut	its trivial in prolog :)
21:01	brehaut	dnolen: even using fogus's unifier i still have to be fairly explicit about the solving steps
21:01	brehaut	dnolen: https://github.com/brehaut/monkey-and-banana if you are interested
21:02	brehaut	i want to have a crack at getting a logos version done too
21:02	dnolen	brehaut: have you looked at logicT ?
21:02	brehaut	dnolen: nope? what is it
21:03	brehaut	logic monad transformer?
21:03	dnolen	brehaut: yeah, Oleg's implementation in Haskell of miniKanren's core ideas.
21:03	brehaut	huh. thats definatly something i need to read up on
21:04	dnolen	brehaut: http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.84.6597&rep=rep1&type=pdf
21:05	brehaut	dnolen: great, thanks!
21:05	dnolen	brehaut: if you implement anything like that in Clojure I'd love to see that and compare :)
21:06	brehaut	dnolen: i'll have to understand it first :P
21:06	brehaut	but it soudns like something worth doing
21:15	amalloy	brehaut: writing code is a lot less adventurous if you understand it first
21:15	brehaut	amalloy: thats not true if monads are involved :P
21:16	brehaut	also the paper is by oleg, they man has a brain the size of a small galaxy
21:17	brehaut	it dawns on me that thus far none of my experiements in logic programming with clojure have included any notion of a logical variable
21:44	fmw	http://paste.pocoo.org/show/353261/ for some reason an if-not block seems to be executing there, even if it shouldn't. Any idea what I'm doing wrong there?
21:45	amalloy	fmw: ((println
21:45	amalloy	i don't think that is your actual problem (yet), but it will cause you pain eventually
21:46	fmw	amalloy: the whole 3 lines (both println's and (. vintage ...) are supposed to be part of the same block
21:46	fmw	the println's are only for debugging though
21:46	amalloy	there are two ways to fix this problem
21:47	amalloy	well. i guess that depends where the .add is supposed to go. your indentation makes this really hard to read
21:47	fmw	the .add is outside of the if (its added anyway)
21:48	amalloy	okay. so you have two issues here
21:48	amalloy	one is that you've stuck an if-not inside of a doto form where it doesn't realy belong
21:48	amalloy	this is expanding into (if-not document (nil? ...) ((println ...)) (.vintage ...))
21:50	amalloy	the other is that you don't group expressions by wrapping them with more parens: ((println x) (println y)) doesn't mean "print x, then y", it means "print x, then treat the return value of that print as a function and call it with argument y"
21:50	amalloy	you're looking for (do (println x) (println y))
21:51	fmw	amalloy: ok, thanks, that fixes it
21:51	fmw	that as in moving it out of the doto/wrapping the println's in a do
21:52	amalloy	good good
21:53	fmw	amalloy: as to the indentation, is it still objectable with http://paste.pocoo.org/show/353264/ ? if so, why? I suppose indentation is very personal, but I'd like to get used to an idiomatic identation style because I'm just starting out with Clojure anyway
21:54	amalloy	fmw: that's much better
21:54	amalloy	i wouldn't put a newline after the [ in let, but i'm pretty sure there are people who would side with you
21:55	fmw	amalloy: allright. yes, I was debating that with myself when I put it there
21:56	amalloy	btw, you know you don't have to type-hint those variables, right? i mean, feel free if you need performance or like it as self-documenting code, but it's not required
21:56	tomoj	(if-not x (do y z)) == (when-not x y z)
21:56	fmw	amalloy: aye, I know, but I was like: why not?
21:57	amalloy	sure
21:57	tomoj	but, (when-not (nil? x)) seems strange
21:57	tomoj	why not (when x) ?
21:57	amalloy	tomoj: yeah. i wanted to emphasize "what do does" rather than "how i would write the code" which actually sidesteps the problem he was having
21:58	tomoj	sorry, I just got here
21:58	tomoj	did you already make the . point?
21:58	amalloy	no
21:58	amalloy	i just fixed his problem. i haven't addressed ways to make his code better in general
21:59	fmw	so, whats the . point? ;)
21:59	tomoj	whether you asked for it or not: (. age setIntValue x) is less idiomatic than (.setIntValue age x)
22:00	tomoj	I got excited when I saw lucene, then unexcited at couchdb :(
22:00	fmw	tomoj: aww, whats wrong with couchdb?
22:00	amalloy	before any of yours, i would (let [{:keys [distillery title bottler ...]} (:value json-item)] ...)
22:00	amalloy	then you can stop messing around with json maps and just have a bunch of local bindings for the stuff you're interested in
22:01	tomoj	fmw: nothing, I like it quite a lot, I'm just not using it right now
22:01	fmw	tomoj: ok :)
22:02	tomoj	I think there is a beautiful clojure library for solr/lucene that hasn't been written yet
22:02	tomoj	I tried and failed miserably
22:02	amalloy	tomoj: ninjudd and/or lancepantz were at least starting to work on that
22:02	tomoj	it's abstract classes all the way down
22:03	brehaut	i think abstract classes go up rather than down
22:03	amalloy	anyway fmw does my suggestion make sense? i think tomoj will agree that it's more interesting than his suggestions :), so if not let me know
22:04	fmw	amalloy: the :keys suggestion?
22:04	amalloy	right
22:04	tomoj	brehaut: maybe solr's got me standing on my head
22:04	brehaut	tomoj: entirely possible
22:04	fmw	amalloy: yes, I'm trying to implement it atm actually
22:04	amalloy	great
22:04	tomoj	amalloy: agreed
22:05	brehaut	tomoj: one of my friends wrote his own in memory clj text index because it was simplier than trying to grok lucene et al
22:14	amalloy	fmw: if you don't mind, i've rewritten this to remove most of the duplicated code i could find: https://gist.github.com/868661
22:14	amalloy	but since i don't have lucene/couch handy, i don't even know if it compiles, so test with care before including :P
22:15	fmw	amalloy: cool, I think I fully understand the code, even :)
22:15	fmw	cheers
22:15	amalloy	fmw: that's the idea! write each idea exactly once :)
22:16	fmw	amalloy: yes, I get the point and see why this is idiomatic
22:17	amalloy	oh, i bet my change from (Integer.) to (int) broke things, though. don't use that :P
22:18	fmw	amalloy: ok, that was one of the things I was wondering about
22:18	amalloy	a brief attack of amnesia
22:18	amalloy	nothing more
22:18	fmw	amalloy: also, why the when instead of if? AFAIK it does exactly the same, but when is more idiomatic because it implies a do?
22:19	amalloy	fmw: that is one of the two reasons
22:19	joshua__	Anyone here familiar with XSLT?
22:19	amalloy	the other is that, after doing this for a while, seeing an if without an else will make you dizzy: you will never leave one out on purpose
22:19	amalloy	er, on accident
22:19	amalloy	joshua__: it's been like four years but i used to be pretty solid on them
22:19	fmw	amalloy: ok :)
22:19	fmw	point taken
22:20	joshua__	I just tried to implement a html to markdown converter. My attempt can be seen here: https://gist.github.com/868546 It was created by trying to translate this SO answer to Clojure: http://stackoverflow.com/questions/59557/html-to-markdown-with-java
22:21	Derander	Is it possible to use java.nio.file's api to watch files for changes w/o polling in java 6? is there an alternate api for java 6? I can't believe polling has been the way to track files forever
22:21	brehaut	joshua__: have considered enlive instead of xslt ?
22:21	joshua__	brehaut, enlive has an html to markdown function!?!
22:21	brehaut	joshua__: no, but it has general html scrapping functions
22:21	brehaut	and its selector based
22:22	joshua__	brehaut, I'm already using it for the scraping. See: http://173.255.212.42/item?id=1589257
22:23	joshua__	I just don't want it to look ugly, so I'm planning to select only the part of the comment I want with enlive, convert that to html, convert that html into markdown, and than have the backend of comments be markdown
22:25	wooby	Derander: not that i've seen, if you really needed to you could dip into the host api w/ JNA
22:25	wooby	(or jni)
22:26	Derander	wooby: seems unbelievably goofy to me, but okay :-/
22:27	tomoj	I think I managed to get a stupid example with jnotify working reasonably easily once
22:28	wooby	possible someone's already done the goofiness for you, i haven't looked in awhile
22:30	amalloy	wooby: impossible. there is a limitless supply of goofiness to be done
22:39	fmw	amalloy: hmm, thats giving an error for me http://paste.pocoo.org/show/353276/
22:40	amalloy	fmw: missing a ~ in ~document at line 11, sorry
22:41	fmw	amalloy: meh, in hindsight I should've spotted that!
22:41	fmw	thanks though
22:41	amalloy	fmw: i left it in intentionally, to give you practice reading compiler stacktraces.......
22:41	fmw	amalloy: hehe :)
22:46	fmw	amalloy: this one is really inexplicable for me: http://paste.pocoo.org/show/353278/ says java.lang.ClassCastException: java.lang.String cannot be cast to org.apache.lucene.document.Fieldable
22:46	fmw	on the (doto document line, even
22:47	tomoj	is there a reason for add-field to be a macro?
22:47	amalloy	tomoj: i wanted to get the string version of the symbol
22:48	tomoj	ah, I see
22:48	fmw	the error occurs regardless of using a macro or not
22:48	amalloy	since he's doing (Field. "title" title)
22:48	fmw	(if I remember correctly)
22:49	amalloy	oh
22:49	amalloy	er hm
22:50	amalloy	fmw: sure? the easiest explanation would be that my macro is wrong somewhere
22:50	tomoj	presumably age and vintage are strings from the json?
22:50	tomoj	.add on a Document expects a Fieldable
22:50	amalloy	oh
22:50	fmw	tomoj: ah yes they are.
22:50	amalloy	yes thanks
22:51	fmw	its not being used for vintage/age though
22:51	fmw	the macro
22:51	amalloy	fmw: see the last two lines
22:51	amalloy	you mean age-field, not age
22:51	fmw	amalloy: ah yes
22:52	fmw	I corrected that in the let, but copied your code without thinking elsewhere.
22:52	tomoj	does using the name of the local binding for the field name not seem a bit strange? very terse and pretty, but..
22:52	fmw	I don't like the stack traces yet, really, so hard to see where you're going wrong exactly
22:53	amalloy	tomoj: i wouldn't object if you called it gross
22:54	amalloy	if you wanted to make it into a function and pass the string manually i guess that would be okay with me
22:55	amalloy	better i guess would be to create a function version, and wrap it in a macro that uses the local binding
22:56	tomoj	dunno that it's bad, just strange and different
22:57	amalloy	tomoj: part of my campaign to never type the same symbol twice in any program
22:58	tomoj	my analogous code just took a map of keywords for field names to values
22:58	tomoj	but solr took care of all the per-field properties
22:58	amalloy	tomoj: i have a keywordize macro i use occasionally: (keywordize [a b c]) expands to {:a a :b b :c c}
22:59	amalloy	it's pretty common that N different functions refer to some stuff by the same names, and want to pass around data in a map
23:00	tomoj	then again, do the per-field properties really belong in create-document?
23:00	tomoj	nevermind, it's 30 lines of code :)
23:01	amalloy	the dude wants code to add some fields to a thing? he gets code to add fields to a thing
23:01	fmw	heh
23:01	tomoj	is lucene schemaless?
23:01	tomoj	never used it except through solr
23:02	fmw	tomoj: as in that it doesn't require all fields for every document?
23:02	tomoj	I mean, you could add whatever fields with whatever names/properties you wanted?
23:03	fmw	tomoj: yes
23:04	amalloy	hey ossareh, were you at the clojure meetup? nobody ever said "hey i'm ossareh"
23:09	tomoj	amalloy: I think it's that it blurs the distinction between code and data in a way I just haven't really seen before
23:10	tomoj	but the more I think about it, the more it seems like that might be a good thing
23:10	amalloy	tomoj: well, glad to have opened your mind, i guess, whether or not you decide you like it
23:12	tomoj	:)
23:13	tomoj	being without keywordize when you need it is certainly ugly
23:14	amalloy	heh
23:15	amalloy	needing it is usually a bad smell anyway
23:16	phenom_	does clojure have a sort of circular linked list or ring-like data structure ?
23:17	tomoj	for what?
23:17	brehaut	&(take 10 (cycle [:a :b :c])
23:17	sexpbot	⟹ (:a :b :c :a :b :c :a :b :c :a) ; Adjusted to (take 10 (cycle [:a :b :c]))
23:18	phenom_	well, i've got a list but id like to read the first element, then rotate left (so the head goes to the end and everything shift over 1)
23:18	brehaut	phenom_: cons pairs are you easiest route to cycles
23:19	phenom_	cons pairs ?
23:19	brehaut	,(cons 1 ())
23:19	clojurebot	(1)
23:19	brehaut	,(cons 2 (cons 1 ())
23:19	clojurebot	EOF while reading
23:19	brehaut	that'll teach me to use clojurebot
23:19	tomoj	guess the question is, do you need to edit it during these read/rotates?
23:20	brehaut	tomoj wins for best question
23:20	phenom_	tomoj, well, other threads may edit it
23:20	tomoj	then it's an interesting problem
23:20	tomoj	:(
23:20	phenom_	i was using a [index, content] pair
23:21	phenom_	"head" was (nth content index)
23:22	amalloy	ken wesson implemented a ringbuffer on the mailing list a while ago
23:22	brehaut	phenom_: can you back up a step and explain what you are trying to solve?
23:23	amalloy	but in general i like brehaut's answer better. instead of asking for a data structure to solve a problem (which you've usually created for yourself), look for a better approach to the problem
23:24	phenom_	well, i've got a list of items, i need to get the first element, then rotate the list ... other threads might be adding elements to the end of the list or removing elements from anywhere within the list
23:24	amalloy	phenom_: what do you mean, get the first element then rotate the list? "rotating the list" sounds like an artifact of your implementation, not your requirements
23:25	phenom_	i want to cycle through the list
23:25	amalloy	ie, it sounds like you're really looking for a bounded-size queue
23:25	amalloy	and you want to let other threads delete things from the list while you're doing that? prefer suicide
23:25	phenom_	well, using refs :P
23:26	amalloy	that's not going to make it less confusing
23:28	phenom_	amalloy ... let's say you've got a list of email addresses and a system that receives requests to send out email ... everytime you get an email, you cycle through the list of addresses, send it to exactly one, then rotate the list
23:29	phenom_	so: list = a@a.com, b@b.com, c@c.com ... request one get's mailed to a@a.com, then the next request to b@b.com etc.
23:29	amalloy	why would my system do that? i can't imagine a real-life scenario where i would say "here is an email, please send it to someone on this list but i'm not sure who"
23:29	phenom_	that's beside the point
23:30	brehaut	phenom_: what requirement forces you to remove from anywhere in the list?
23:30	amalloy	i don't think it is. refs or no, if you introduce concurrency to this model your performance will be basically random
23:31	amalloy	like, i was thinking "maybe he's doing load-balancing for a set of servers"
23:31	amalloy	but you might as well just assign randomly in that case, it will all work out on average
23:31	brehaut	phenom_: is it some sort of priority requirement?
23:31	phenom_	no priority
23:31	phenom_	just round-robin
23:32	brehaut	its not round robin if you take randomly
23:32	phenom_	well, server 4 may go down
23:33	amalloy	phenom_: so? keep an unordered set of servers and assign randomly to any that are still working. no reason to futz with keeping an ordered list
23:34	phenom_	amalloy: the requirement is to do sequentially in the order they were added to the list
23:35	brehaut	phenom_: it sounds like you want a clojure.lang.PersistentQueue in some reference type
23:35	brehaut	or alternatively to restructure your program to run in an agent
23:36	brehaut	your third option is to not use a persistent queue type and switch to a java concurrent queue which is blocking
23:36	tomoj	wouldn't you need a dequeue?
23:36	phenom_	brehaut: but how do i get the round-robin behaviour? dequeue then requeue ?
23:37	tomoj	er, deque
23:37	brehaut	phenom_: round robin is the consumeres taking turns
23:37	brehaut	im not sure how thats a data concern
23:38	tomoj	yyy ju'i nai
23:38	phenom_	brehaut: the logic to forward requests to the appropriate server ... how would that be done in round-robin then ?
23:38	phenom_	given a list of servers
23:39	brehaut	cycle your list of servers, send a message to each server to to get work, server requests work?
23:43	phenom_	brehaut: the problem with that is given list [s1 s2 s3], when the first request comes it it should be sent to s1, when the second comes in (possibly in a different thread), it needs to go to s2
23:44	phenom_	meaning, the system doesn't know up front all the requests ... it's done as it's picked up off the network
23:47	amalloy	phenom_: how can it be a "requirement" that servers be assigned to strictly in order, when you have to be tolerant to them disappearing at any time?
23:47	brehaut	phenom_: i think we are talking passed each other now. i have no idea what you want that i havent mentioned previously
23:47	brehaut	i know that if i had n servers and 1 work queue, i would just use a blocking work queue
23:48	brehaut	and make the workers request items off it as fast as they could
23:48	brehaut	and not owrry about trying to implement some addition round robin scheduling
23:48	phenom_	okay, maybe load balancing is the wrong anaolgy
23:49	phenom_	how about a message queue ... you have n subscribers but you want an incoming message in a queue to be sent to exactly one and only one ... so you use a round robin system
23:49	brehaut	phenom_: i wouldnt. i would us a blocking queue
23:50	amalloy	indeed
23:50	brehaut	phenom_: the blocking queue ensures all the concurrency semantics around dequeueing one item to each requester, in order, and such that if there is no work to do, nobody spins
23:50	amalloy	what if one message were really long? or one server were really slow? round-robin makes no sense
23:51	phenom_	subscribers are passive ... the messages need to be pushed over the network
23:52	amalloy	that's even more nuts. how will you find out if a subscriber crashes?
23:52	phenom_	ack/nack expiry
23:53	amalloy	in the meantime you've wasted time sending him N requests he never got, and you've had to remember them so you can reassign them to someone else
23:53	amalloy	just make the subscribers ask you for data like brehaut says
23:53	phenom_	assume the other :P
23:53	phenom_	the problem is the cycling
23:53	amalloy	anyway apparently my being opinionated isn't solving your problem, and i don't have real ideas. afk