#clojure – 2011-05-24

2011-05-24

02:41	markoman	I want to split string and include original value on set, what is an easy way to do this? (split #" " "some phrase") -> ("some" "phrase" "some phrase")
02:44	brehaut	(defn str-split-retain [s sep] (into #{s} (.split s sep))) ?
02:49	markoman	works great, thanks
02:50	brehaut	it has a terrible name though :P
02:51	no_mind	is it possible to introduce new tags with enlive html ?
02:53	markoman	name doesnt make man worse, they tell :)
02:53	thorwil	no_mind: i think it has no idea about specific tags, so i guess yes
05:07	clgv	is there something similar to juxt that allows me easily to combine funtions which create a map where every function provides a key and a value?
05:19	clgv	hm ok, I looked in clojure and contrib - there seems to be nothing. so I just build my own
05:23	ejackson	look a bit idiosyncratic
05:23	ejackson	i guess
05:27	clgv	why do you think?
05:28	clgv	my use case is (juxt-map :key1 func1 :key2 func2) that generates a function f that returns a map instead of a vector like juxt does
06:21	clgv	Is there a condition checking idiom for macro parameters?
06:23	clgv	assert-args from core is private unfortunately.
06:31	cemerick	clgv: if the fn does what you want, there's always the #'clojure.core/assert-args backdoor.
06:32	clgv	cemerick: so I should do a "with-private" hack with assert-args?
06:32	cemerick	with-private?
06:33	cemerick	It's not a hack; you just need to be prepared for potential breakage if assert-args changes
06:34	clgv	ok :(. Maybe it should be made public in general
06:34	clgv	wrong smiley...
08:07	no_mind	in enlive, how do i find the value of an attribute for a given node ?
08:16	mefesto`	no_mind: (:attrs node) ?
08:16	mefesto`	or possibly: (get-in node [:attrs :blah])
08:21	raek	no_mind: you can use select to extract the node in question (which is represented as a map with keys :tag, :attrs and :content) and then do as mefesto` said
08:24	no_mind	the problem is how do I pass the node to get ?
08:24	clojurebot	People have a problem and think "Hey! I'll use a regular expression!". Now they have two problems....
08:24	no_mind	let me paste teh code
08:25	no_mind	here is the code http://pastebin.com/JsWS7seg . How do I pass the node ?
08:28	raek	no_mind: is this for transforming a html tree, or extracting data form it?
08:28	raek	no_mind: a transformation is a function that takes a node and returns a node or a sequence of nodes
08:30	no_mind	raek: actually transformation. I need to apply a transformation function based on the type of form element. For which I need to first extract the "type" attribute.
08:30	raek	no_mind: to just get the value: (let [tree (html/html-resource "something.html") node (select tree [(html/id= "entity_label")]) attr (get-in node [:attr :foo])] attr)
08:32	raek	the transformation function could look like (fn [node] (let [type (-> node :attrs :type)] (case type "foo" <foo code> "bar" <bar code> <default code>)))
08:34	raek	(this probably looks prettier if you turn it into a defn)
08:34	no_mind	raek: Let me detail teh problem. I have a html file which has a form. I need to serve this html file by filling the values in form elements. The values of form elements is available as a map containing the elementid as key and corresponding value as the value to be set
08:38	raek	no_mind: but then you don't need to look at the type attribute, right? I think you just need to make one rule for each entry in the map, where the selector is as in your existing code and where the transformation is (set-attr :value "element value")
08:39	raek	(html/at tree [(html/id= "username")] (set-attr :value "raek"))
08:39	no_mind	I need to lookup :tag not :type . The (set-attr :value "value") will work for input type elements butfor checkboxes, select, multi-select we need more work
08:40	raek	I see.
08:40	no_mind	so I was thinking of writingmulti-method for filling value
08:40	no_mind	butfor multi-method to work, I should be able to identify the type of the node
08:42	raek	(defn tag-multi [node] (the-multi-method (:tag node) node))
08:43	raek	oh, wait.
08:43	raek	no need for that extra function.
08:43	no_mind	then
08:43	no_mind	?
08:43	raek	(defmulti your-multi-method (fn [node] (:tag node))) ; this should be enough
08:44	raek	this will make the multimethod dispatch on the element type
08:44	no_mind	raek: Icouldfigure that but cannot figureout how to pass the node from enlive selector
08:45	raek	no_mind: you just do it like this in your at form: (html/at tree ...selector... your-multi-method)
08:45	raek	no_mind: here, "your-multi-method" will receive the node as its only argument
08:45	no_mind	oh ok
08:46	raek	hrm. but you probably want the text value to be passed too...
08:47	timvisher	morning everyone
08:47	raek	(defn fill-in [text] (fn [node] (your-multi-method [node text])))
08:47	raek	(defmulti your-multi-method (fn [node text] (:tag node)))
08:47	timvisher	what could cause a binding expression to _not_ rebind the var, other than perhaps a typo?
08:47	raek	(html/at tree ...selector... (fill-in "value"))
08:48	raek	timvisher: laziness
08:48	timvisher	raek: could you explain that a bit further?
08:48	raek	,(binding [out :foo] (lazy-seq (cons out nil)))
08:48	clojurebot	(#<StringWriter >)
08:49	timvisher	ahh
08:49	raek	,(binding [out :foo] (doall (lazy-seq (cons out nil))))
08:49	clojurebot	(:foo)
08:50	raek	so the lazy expression does not remember the binding of the var...
08:50	timvisher	and it turns out that deftest runs lazily, i suppose?
08:50	timvisher	that explains a lot of what i've been expriencing
08:51	no_mind	raek: no luck http://pastebin.com/7UF3ZbRw
08:51	timvisher	i've been assuming that i could wrap all of my deftests in a single binding expression and get a global change
08:51	timvisher	but i suppose i need to wrap the is expressions instead
08:51	jjido	shouldn't doall force evaluation before the binding is lost?
08:52	dnolen	jjido: yes, but beware of nested lazy-seqs.
08:53	jjido	dnolen: I see...
08:55	raek	no_mind: remove the parentheses around (abc) since you don't want to pass the return value of the function, but the function itself to envlive
08:55	no_mind	k
08:55	raek	no_mind: tag values are keywords, so it should be :input instead of "input"
08:56	raek	no_mind: enlive will only pass one argument to the supplied function (the node), so it is common to make a closure that remembers "extra arguments"
08:57	raek	(defn helper-fn [arg1 arg2 arg3] (fn [node] (the-real-function node arg1 arg2 arg3)))
08:57	raek	(html/at ... ... (helper-fn 1 2 3))
08:58	no_mind	aha
08:58	raek	here, the call to helper-fn will return a function that takes a node, but when that function is invoked, it also knows ablut arg1 arg2 and arg3
09:02	raek	no_mind: https://gist.github.com/988666
09:03	raek	also note how set-attr is called due to the "two stage" way of doing things
09:16	no_mind	raek: thnxs
11:15	no_mind	raek: around ?
11:15	raek	no_mind: yes
11:17	no_mind	raek: how can one iterateover nodes in enlive. I have a list of nodes in a map with map keys being id of the nodes
11:25	raek	no_mind: you want to transform each entry in the map to one selector-transformation pair?
11:26	no_mind	yes, each node matching the id key in the map
11:30	raek	no_mind: since at is a macro, you can either write a macro that expands into the desired at form, or use loop/recur or reduce and in each iteration make a call to at with only one selector-transformation pair
11:31	raek	no_mind: will the map have different values at runtime? if so, you can't use the macro approach
11:35	raek	no_mind: the second way could look like this: (defn foo [tree form-map] (if (empty? form-map) tree (let [[id value] (first form-map)] (recur (at tree [(id= id)] (abc value)) (rest form-map)))))
11:35	raek	where "abc" is the function from my last gist
11:39	no_mind	ok
11:46	coopernurse	I'm doing this "count a sequence" problem here: http://4clojure.com/problem/22
11:46	coopernurse	My solution: (fn [xs] (reduce + (for [x xs] (+ 1))))
11:46	coopernurse	Site is complaining that I'm using "count", which is prohibited for this problem
11:47	coopernurse	Is there something about for / reduce that I'm not understanding? Or is 4clojure just returning a misleading error message? From what I can tell I'm not using count
11:49	manutter	hmm, for might use count internally
11:50	coopernurse	manutter: I see. maybe they're using trickery to detect that function anywhere in the eval loop?
11:50	manutter	well, I'm just guessing
11:50	manutter	could just as easily be a bug at 4clojure too
11:50	coopernurse	ok, well 200+ people figured it out, so there's clearly another right way to do it
11:51	coopernurse	great site btw
11:51	manutter	It sounds good, I haven't gotten around to visiting it yet
11:51	coopernurse	yeah, I'm new to FP, so I'm really getting a workout
11:51	coopernurse	a bit humbling
11:52	manutter	I know what you mean, fp is almost a zen experience
11:52	manutter	"And then the Master hit him over the head with an 800 page COBOL listing, and he was enlightened."
11:53	coopernurse	yeah, I told my girlfriend it was like learning mandarin after learning 3-4 romance languages
11:53	coopernurse	you think you're good at languages, and then bam
11:53	manutter	indeed
11:55	manutter	If I were going to count a sequence without using count, I'd use a map/reduce, but that's just because map/reduce is also blowing my mind ever since I went to the NoSQL track at the last O'Reilly conf.
11:56	coopernurse	good hint. I'll play with that
11:59	jean-philippe	coopernurse: you might want to read on the reduce function, as it already iterates over the whole sequence, no for needed
11:59	coopernurse	jean-philippe: ok thanks
12:03	jean-philippe	coopernurse: or start from the beginning: knowing that a sequence can be expressed as a box containing a single element (the (first seq) function) and and and pointer to the sequence of the remaining elements (the (rest seq) function), and that the empty list can be checked using (empty? seq), how can you recursively count the number of elements?
12:05	coopernurse	can anonymous functions be recursive?
12:05	wastrel	use recur should work
12:05	coopernurse	thanks
12:05	wastrel	your super welcome :]
12:39	coopernurse	I suspect this is not what you guys had in mind earlier.. but it works
12:39	coopernurse	(fn [xs] ((fn [x xs] (if (empty? xs) x (recur (+ 1 x) (rest xs)))) 0 xs))
12:43	jean-philippe	that's quite right, although it could be a bit cleaner using (loop)
12:43	manutter	I think you were closer to a nice solution with your original snippet tho
12:44	coopernurse	manutter: yes, I think they wanted to force you to learn some other bits of clojure.. or it's a bug in the test :-)
12:44	jean-philippe	the reduce function is just an abstraction of that construct
12:45	raek	coopernurse: instead of nesting functions like this, you can use 'loop'
12:45	coopernurse	raek: thanks. reading docs
12:45	raek	coopernurse: (fn [xs] (loop [x 0, xs xs] (if (empty? xs) x (recur (+ 1 x) (rest xs)))))
12:46	raek	coopernurse: ...but it does exactly the same thing as your version
12:47	raek	I would use inc instead of (+ 1 ...), but other than that, this is what I would have written
12:47	coopernurse	raek: thanks. is the default variable binding in: (loop [x 0, xs xs]) a general thing you can do in functions? or is that a loop specific bit of syntax?
12:48	coopernurse	if I'm reading it correctly, we're saying "set x=0 if not provided"
12:48	coopernurse	or am I reading that incorrect?
12:48	coopernurse	incorrectly
12:48	raek	coopernurse: it is only for loop. think of it as ((fn [x xs] ...) 0 xs), but with a different look
12:49	jean-philippe	it's rather, bind x to 0 in the first iteration of the loop, recur will rebind it according to the parameters
12:49	raek	coopernurse: you must always provide a value
12:49	coopernurse	I see
12:50	raek	it has the same syntax as let, but works as fn/recur
12:50	coopernurse	from the docs it sounds like loop avoids recursion under the hood
12:50	coopernurse	so it's faster than my first example that used a nested function
12:50	coopernurse	and won't blow up the stack if xs has lots of elements
12:50	raek	actually, in this case there is no big difference, since you use recur in the other case too
12:51	jean-philippe	for completion's sake, here's the reduce version (fn [xs] (reduce (fn [acc x] (inc acc)) 0 xs))
12:51	raek	i.e. the avoiding-stack-overflow-magic lies in 'recur'
12:51	manutter	you're on the right track with your description of loop/recur
12:51	coopernurse	raek: oh, I see. thanks
12:51	manutter	right, what he said :)
12:53	coopernurse	wild stuff. very terse. curious how long it will take my brain to read these types of constructs
12:54	coopernurse	but I understand why people find lisp elegant. there really isn't much syntax
12:54	amalloy	coopernurse: we macroexpand the form before checking it
12:54	coopernurse	the hard part is learning the vocabulary of all the abstractions built on it
12:56	coopernurse	jean-philippe: the reduce version reads much more cleanly imho.
12:56	amalloy	the solution i find most elegant, though it's not shortest, is (fn [coll] (reduce + (map (constantly 1) coll)))
12:57	amalloy	which is more or less what you were doing, coopernurse, but with map/constantly intead of for
12:57	coopernurse	amalloy: that is nice.
12:57	coopernurse	btw, what's the party line for making sure your arguments don't name collide with functions?
12:58	amalloy	coopernurse: who cares? shadowing is fine
12:58	amalloy	some disagree with me, of course
12:58	ataggart	avoid it if it can be confusing to a reader, otherwise, meh
12:58	manutter	amalloy: So, if that's not the shortest, what is?
12:58	amalloy	but (fn [list] (map inc list)) is pretty clear if the input is a list
12:58	technomancy	which aren't very descriptive args to begin with
12:59	coopernurse	amalloy: I see.
12:59	ataggart	I think there's a list of idiomatic arg names somewhere
12:59	amalloy	#(.size (vec %)) is probably shortest, but it's surely cheating
13:00	coopernurse	yes, one of the clojure books I'm reading (not sure if it's Joy of Clojure or the pragmatic prog's book) has a list
13:01	amalloy	btw coopernurse, if you want to talk to the devs we generally hang out in #4clojure when we're around
13:01	coopernurse	amalloy: ah, great
13:04	manutter	heh, short == true, cheating == true, check check. :)
13:05	manutter	kinda like it tho
13:10	amalloy	&(.size (vec '(1 2 3 1 2 3)))
13:10	sexpbot	⟹ 6
13:10	amalloy	whew. (true? working) also
13:24	dnolen	interesting core.logic can solve the Einstein constraint problem in < 2ms now, making it nearly 40 times faster at that particular problem than the Prolog implementation in Qi.
13:25	ataggart	dnolen: what reading material do you suggest for someone to be able to grok core.logic?
13:26	dnolen	ataggart: The Reasoned Schemer, William Byrd miniKanren dissertation, Bratko's Prolog for Artificial Intelligence Programming
13:26	ataggart	thx
13:28	defn	good day, gents.
13:30	defn	back in a moment...
13:32	Pisketti	Speaking of books (for noobs), any suggestion for someone who wrote his first line of clojure a few months ago?
13:33	Pisketti	I read Practical clojure and Programming clojure is waiting. I've also thought about ordering The joy of clojure.
13:33	Pisketti	But other than that, any fundamental must-reads?
13:33	Pisketti	SICP maybe? Little schemer?
13:33	nishant	Hey everyone, I'm using the extend construct to make some java classes conform to a clojure Protocol. I am then loading these classes using load, however when I am calling a function on one of these classes, the same function from a different class is invoked, which leads to a "java.lang.IllegalArgumentException: No matching method found" exception. help!
13:34	chojeen	just bought "the joy of clojure", it's pretty nice for a beginner (read: me)
13:34	technomancy	hiredman: I bought that book from zed shaw.
13:35	Pisketti	chojeen: really? I thought it was the first not-the-first-to-read-on-clojure ever written ;)
13:35	hiredman	mine has a "USED" sticker on it, so I think it was a textbook
13:36	amalloy	Pisketti: it was my first clojure book
13:36	amalloy	(and only, thus far)
13:36	Pisketti	amalloy: but you were not a beginner
13:36	amalloy	when i read it back in july i was
13:37	chojeen	pisketti: sure, but I felt like a challenge, and coming from a decent functional background helps
13:37	amalloy	only had a few weeks' self-taught common lisp under my belt
13:37	Pisketti	I thought you were an old lisp guru :D
13:38	amalloy	JoC is good. it's a little less spoon-fed than the others (i'm told), but if you expend some effort you will learn lots from it whether you know clojure or not
13:38	Pisketti	Goes to show you can learn it pretty fast
13:38	amalloy	indeed
13:38	amalloy	i'm not old enough to be an old lisp guru :P
13:38	chojeen	I've never found "beginners" books all that helpful, anyway
13:39	qed	JoC is great.
13:39	qed	amalloy: age has nothing to do with guruship.
13:39	amalloy	qed: he said "old lisp guru"
13:39	Pisketti	chojeen: Yeah, they tend to be geared towards beginner programmers (of any language) which isn't necessarily the case
13:40	amalloy	but yes, i'm aware. i've taken on the mantle of git guru in an organization or two
13:40	coopernurse	I'm 4 days into Clojure. reading JoC and Programming Clojure - both are good. JoC is more complete.
13:40	amalloy	SICP starts by introducing what programming is, but then it gets heavy fast. what a book
13:41	dnolen	nishant: do you have a simple paste of your problem?
13:42	chojeen	JoC appealed to me because it claims to teach "the clojure way", i.e. idiomatic clojure
13:42	Pisketti	http://sicpinclojure.com/ <-- This is extremely interesting. Does the person behind this happen to be on this channel?
13:42	qed	Pisketti: I think he used to be, not sure if he's around anymore.
13:42	qed	It's too bad it hasn't continued. I'm floating the idea to a few people to pick up where he left off.
13:44	Pisketti	qed: Do it! Seriously, that would be a great service to the community. :)
13:45	amalloy	Pisketti, qed: https://github.com/vu3rdd/sicp seems to exist
13:45	Pisketti	Mmm, interesting
13:45	amalloy	might be an easier starting point
13:47	Pisketti	Thanks, I'll check it out.
13:47	Pisketti	How about Little schemer?
13:48	dnolen	Pisketti: Little Schemer is good for picking up the basics of idiomatic Lisp style.
13:48	Pisketti	Or even Land of Lisp. I bought that to a friend, and once he has finished it, I'll read it too.
13:49	Pisketti	dnolen: that's exactly what I'm looking for
13:49	dnolen	Land of Lisp also good but too broad in scope to spend much time on Clojure's unique strengths
13:50	Pisketti	I'm thinking a healthy dose of basics of functional programming would do me good
13:52	Pisketti	There's also Let Over Lambda. I just somehow get the feeling that it might be too hardcore for me at this point
13:52	Pisketti	Not sure though
13:53	amalloy	On Lisp is probably not a good clojure book, but it's a good lisp-in-general book
13:53	qed	Little Schemer is a fun read.
13:54	amalloy	and it has the advantage of beeing free
13:54	qed	The curriculum for learning a lisp is kind of a big mixture IMO.
13:55	qed	It's hard to say there's one approach that everyone should use.
13:55	amalloy	qed: i mostly just loved the gorgeous writing in On Lisp
13:55	amalloy	reminds you lisp is a beautiful language
13:56	qed	I'm going to pick up another copy, on that note.
13:56	imade	hello, how's the easiest way to make a list of functions, let's say I have functions last1, last2, last3, last4
13:57	amalloy	[last1 last2 last3 last4]: a list! probably not what you're looking for, though; what do you want to do with that list
13:57	qed	&[(fn [x] (+ x 1)) (fn [x2] (+ x2 1))]
13:57	ataggart	xy?
13:57	sexpbot	⟹ [#<sandbox11964$eval14849$fn__14850 sandbox11964$eval14849$fn__14850@2100f3> #<sandbox11964$eval14849$fn__14852 sandbox11964$eval14849$fn__14852@1541c3f>]
13:57	clojurebot	xy is http://mywiki.wooledge.org/XyProblem
13:57	imade	right now I am trying to do (for [f '(last1, last2, last3, last4)] (f '(1, 2, 3, 4))), but it returns (nil nil nil nil)
13:58	qed	you don't need for
13:58	amalloy	$google clojure list vector difference quote
13:58	sexpbot	First out of 433 results is: Clojure - cheatsheet
13:58	sexpbot	http://clojure.org/cheatsheet
13:58	amalloy	bah
13:58	imade	I am trying to simplyfy my unit testing
13:58	qed	imade: which version of clojure
13:58	amalloy	qed: for is a fine solution. it's the ' that's a problem
13:58	imade	(deftest test-last
13:58	imade	(dorun
13:58	imade	(for [f '(last1, last2, last3, last4)]
13:58	imade	(is (= 4 (f '(1 2 3 4)))))))
13:58	raek	imade: what you wrote is a list of symbols, not a list of functions
13:58	ataggart	,(doc clojure.test/are)
13:58	clojurebot	"([argv expr & args]); Checks multiple assertions with a template expression. See clojure.template/do-template for an explanation of templates. Example: (are [x y] (= x y) 2 (+ 1 1) 4 (* 2 2)) Expands to: (do (is (= 2 (+ 1 1))) (is (= 4 (* 2 2)))) Note: This breaks some reporting features, such as line numbers."
13:59	imade	but currently it's failing
13:59	amalloy	&((juxt inc dec) 1)
13:59	sexpbot	⟹ [2 0]
13:59	ataggart	imade: use clojure.test/are
13:59	technomancy	amalloy: was wondering how long it would take before you pulled out el juxt
13:59	raek	imade: you probably want [last1 last2 last3 last4] (as amalloy suggested) or (list last1 last2 last3 last4)
13:59	raek	the first is more ideomatic, though
13:59	imade	k, thanks, will try them out
14:00	amalloy	technomancy: i wanted to point out the problem with the current approach first. i hope that doesn't make me a bad person
14:00	raek	but in the case of clojure.test, 'are' already solves this problem as ataggart pointed out
14:01	Pisketti	Is there any other reason for choosing a vector over a list other than "adding" to the end is faster?
14:01	amalloy	writing them in source code is easier
14:02	amalloy	and using a list gives a strong hint "these might be used as code, not data"
14:02	Pisketti	true
14:06	Pisketti	amalloy: btw, are you (one of) the creator(s) of 4clojure?
14:06	amalloy	yep
14:06	amalloy	(one of)
14:07	Pisketti	Ok. It's probably the best learning tool I've come across.
14:08	Pisketti	Mostly because it's so much fun. :)
14:08	coopernurse	Pisketti: I second that
14:08	coopernurse	although it is destroying my work productivity :-)
14:08	amalloy	the site's only been around for a little over a month. we're very pleased with the reception it's gotten
14:09	dnolen	interesting Clojure protocols have the same limitation as Haskell typeclasses (as opposed to Standard ML functors) - you should really only extend a type to a protocol once.
14:09	Pisketti	coopernurse: I've fought hard not to open the page at work.
14:10	amalloy	hah
14:10	coopernurse	Pisketti: I lack the willpower
14:10	Pisketti	:)
14:10	amalloy	worse when you can work on it at work
14:10	qed	yeah 4clojure is awesome.
14:10	Pisketti	amalloy: What I really miss, is a feature that would allow the users to compare solutions
14:10	qed	It's like an interactive Project Euler, which I found equally addictive.
14:10	Pisketti	Exactly
14:11	coopernurse	another site to never go to: http://www.coderloop.com/
14:11	amalloy	Pisketti: #4clojure on twitter
14:11	amalloy	and under Account Settings you can join the competition for finding the shortest solution
14:11	qed	Pisketti: we've been discussing that, but IMO it's a good idea to divorce solutions from the site to stop people from peeking too much.
14:12	qed	As it stands right now you can go out to Twitter and do a bit of searching to reveal a solution, which is bit bigger barrier than say, a button that says "CHEAT!" on each problem page. :)
14:12	pdk``	there's no real purpose to a "project euler for clojure" sort of site if people can copy paste crap :p
14:12	Pisketti	amalloy: sure twitter helps and that's what I've been doing but I'm thinking something like a forum.
14:12	pdk``	or better yet
14:12	pdk``	make 4clojure 2
14:12	pdk``	where we copy paste assignments from our bosses and ask the public at large to solve them
14:13	qed	(second foreclojure)
14:13	qed	pdk``: i don't that's the logical next step ;)
14:13	amalloy	pdk``: that's already where all the problems i pose come from. my boss is always asking me whether this object i can't see is a vector or a list or what
14:13	qed	bahahaha
14:14	qed	it's like rich's talk at the (first clojure-conj): factorial, the problem we need to solve every day at work
14:14	qed	something along those lines anyway, not a direct quote, but funny either way
14:14	Pisketti	I don't care about solving the problems per se. I just would like to see what kind of approaches other people have used once I get my own initial or second or third solution working for any particular problem
14:15	qed	Pisketti: sure, but then what incentive do you have to think about making your solution smaller?
14:15	amalloy	qed: so what? not everyone wants to optimize their own solution in isolation
14:16	qed	amalloy: yeah I don't either really
14:16	qed	I guess I'm just saying having a barrier to peeking is nice, even if its superficial
14:16	Pisketti	But that's point. I spend a lot of time optimizing each problem and write several versions. When I'm "done", I'd like to see how other people dit it to _learn_.
14:16	qed	s/its/it's/
14:16	sexpbot	<qed> I guess I'm just saying having a barrier to peeking is nice, even if it's superficial
14:17	qed	Pisketti: nod
14:17	amalloy	Pisketti: at some point i'd like to add some kind of feature for seeing other user's solutions
14:17	amalloy	but how to make it usable is unclear
14:17	Pisketti	I's like you can only learn so much by writing your own code (= keep making the same mistakes). Seeing other people's code can be an eye opening experience
14:18	amalloy	if you want to submit an issue at https://github.com/dbyrne/4clojure/issues, having a user request will help
14:18	qed	Pisketti: but then it sort of cheapens the idea of having the smallest solution -- what incentive do most users have to slim down their solutions if they can just peek at the smallest solution and paste it in
14:19	Pisketti	qed: personally I don't care about the copy-pasters. I just want to learn.
14:19	qed	Pisketti: nod -- I guess part of what I've learned as a result of not seeing solutions is that I've been getting better and better at being clever about slimming down my solutions
14:19	amalloy	Pisketti: yes; i was the one to implement the "shortest solution" feature, but i think qed is a little too focused on it, when it's one of many good ways to learn and have fun
14:20	amalloy	we absolutely want to cater to you too, but catering to both is tricky. like i said, an issue request will help
14:20	qed	amalloy: id agree with you i am too focused on it
14:20	qed	:)
14:20	coopernurse	qed: agreed. I'm enjoying the fact that I can't see other answers
14:20	qed	that being said, the focus on that aspect has been really fun and interesting
14:21	coopernurse	I know that I would have cheated. I honestly don't want to tell you guys how long I'm spending on some of these problems. It's embarrassing
14:21	qed	ive been keeping a log of my solutions -- i do a "most readable" solution, followed by a smallest solution possible
14:21	amalloy	qed: that sounds fun
14:22	qed	that combination is really great -- you get your head around the problem, see the "shape" of the solution, and then find out how to condense that "shape"
14:22	amalloy	back when we weren't storing solutions for you, i stored them manually, but keeping multiple copies is too much work for me :P
14:22	qed	amalloy is in the server room manually typing your solutions into a 286
14:22	imade	k, so the updated version of my unit test is like this, is it idiomatic now or could I improve it further somehow (deftest test-last
14:22	imade	(dorun
14:22	imade	(for [f [last1, last2, last3, last4]]
14:22	imade	(are [x coll] (= x (f coll))
14:22	imade	4 '(1 2 3 4)
14:22	imade	nil '()
14:22	amalloy	hahaha
14:22	imade	1 '(1)))))
14:22	amalloy	i meant store my solutions manually
14:22	qed	:D
14:23	amalloy	imade: https://gist.github.com next time you paste something long, please
14:23	imade	aa, k, will do
14:23	amalloy	dorun/for is evil. just use doseq instead, which is like for with a dorun baked in
14:23	qed	I do a split window: 4clojure.clj and a REPL -- bounce back and forth, then paste my solutions into 4clojure
14:23	qed	and usually realize at that point I didn't account for one of the cases appropriately
14:23	qed	:)
14:25	imade	thanks, amalloy
14:25	imade	here's the gist also https://gist.github.com/989314
14:26	amalloy	i don't know how `are` works, but i'd replace '(1 2 3 4) with [1 2 3 4], and similarly elsewhere
14:27	imade	k vector, cause it indicates it's a data
14:28	amalloy	nod i mean, lists can be data too, and vectors can be code - it's lisp - but vectors are much more convenient when you want data
14:29	imade	yep
14:29	imade	wow, it's awesome how short this form of testing can be
14:32	qed	imade: not to mention how much less you /need/ to test in general :)
14:33	imade	yeah
14:33	amalloy	yes. it's very hard to get (map #(* 2 %) some-list) wrong
14:34	Cozey	OT: Do You develop javascript / css on web apps? What is the Lisper's favourite developing pattern for these? CoffeeScript? SCSS? QUnit for testing? or is it something on node.js - or - plain old code-'reload'-check in firebug pattern?
14:35	ataggart	imade: see the comment I added to that gist
14:36	imade	thank you ataggart, I edited the gist according to the recommendation
14:37	amalloy	ataggart: i love that you can fork gists. seems more intuitive to me than writing code in the comments
14:38	gfrlog	I love that you can gork fists
14:43	dnolen	Cozey: I just write regular JS / CSS + Webkit Inspector + reload.
14:43	technomancy	Cozey: if I were doing web work I'd use coffeescript
14:43	Cozey	i wonder if with all what is happening now in node.js environment (NPM packages etc), the way we code js for the browser will improve
14:44	technomancy	I just get so sick of playing the "where did I forget to put the explicit return" game
14:44	Cozey	personally i hate coding js in the browser because it takes so much time to find and fix bugs
14:44	Cozey	or 'where did this exception come from'
14:44	Cozey	or even better 'why my browser swollowed an exception'
14:45	dnolen	Cozey: WebKit debugger is quite good, but then again I have 7 years experience w/ client-side JS
14:45	Cozey	also i don't feel like clojure-script comming to the rescue very soon
14:45	Cozey	dnolen: do You use some frameworks except for instance jQuery/ Prototype etc?
14:45	Cozey	some object oriented thingy or functional one ?
14:46	dnolen	Cozey: currently using mixture of Underscore, jQuery, and some hand-rolled OO-like thing sans inheritance.
14:46	gfrlog	there's no way to destructure sets is there? :(
14:46	Cozey	and what do you thing bout node.js popularity? is it so super fast and cool 'older' languages: java/python/ruby - or clojure can't beat them?
14:46	Cozey	is js faster then clojure btw?
14:47	edw	JavaScript would be significantly less painful if it simply adopted some sort of shorthand anonymous function syntactic sugar.
14:47	dnolen	Cozey: no
14:47	coopernurse	Cozey: there was a benchmark someone did of a node.js vs Compojure site. Perf was about the same
14:47	dnolen	Cozey: I've used node.js for file-streaming, it's good for that. I've use for rapidly prototype network stuff good for that as well.
14:48	qed	(inc rapid-prototyping-with-node)
14:48	sexpbot	⟹ 1
14:48	ataggart	gfrlog: (seq a-set)
14:48	qed	(inc dnolen)
14:48	sexpbot	⟹ 3
14:48	gfrlog	ataggart: yeah, that's what I've been doing. Takes a whole nother (let) expression.
14:48	coopernurse	Cozey: the GC in V8 (node) isn't as advanced as the JVM from what I've read. I believe it's stop-the-world.. so you get some spikes in response time periodically
14:49	dnolen	Cozey: at the same time node.js can't fix a broken language. So I'm not really interested in node.js for anything but small projects w/ very limited goals.
14:49	qed	what's up with disclojure.org? No update since May 11th?
14:49	edw	technomancy: I think it has something to do with the fact that there are a lot of domains that no longer need big-ass web app frameworks e.g. RoR and Django and Node.js is the easiest way to write non-bloated web services.
14:49	coopernurse	dnolen: agreed. I'm actually porting a hobby site off of node.js
14:49	dnolen	Cozey: I also find the idea that code can easily be shared between server and client w/ Node.js absurd. Client code is filled with client crap. Server code filled w/ server crap.
14:50	coopernurse	dnolen: this was exactly what I wanted to explore. I found no shared code opportunities of any importance. client was all jQuery - very little html templating on the server
14:50	qed	dnolen: SoC
14:51	edw	technomancy: It's the triumph of XHR & Ajax: Node.js programs are basically adpters between NoSQL databases and JavaScript code on a client. Of course, it's like putting a loaded gun in the hand of a child in that it "empowers" every copy-and-paste JS monkey to start writing server-side stuff.
14:51	qed	sometimes things are too powerful, even for us...
14:51	technomancy	edw: sorry, still baffled. =)
14:52	coopernurse	edw: very good observation. but the avg node.js developer I've encountered is pretty skilled
14:52	qed	(see my first experience with pmap)
14:52	qed	"Oh, I just add a p and it all happens in parallel!"
14:52	edw	coopernurse: Yeah, I'm more bracing for the inevitable impact.
14:52	Cozey	edw: do you predict the age of node.js security horrors? ;-)
14:52	technomancy	http://p.hagelb.org/async.jpg
14:52	coopernurse	edw: heh.. yes. they'll need to dumb down the installation process first, although homebrew supports it now
14:52	dnolen	SpiderNode is also interesting, but the Node.js community seems filled with adolescent coders who can't really see what that project is trying to do - which is makes JS on the server not suck.
14:53	dnolen	I got mad respect for Brendan Eich and David Herman and the Mozilla Team, they're trying hard to make JS compete w/ programming languages circa 2000.
14:53	technomancy	you can't library your way out of the statement/expression distinction.
14:54	amalloy	technomancy: clojure is a pretty good library for java
14:54	technomancy	probably a lost cause
14:54	technomancy	amalloy: sure, the runtime is not a lost cause =)
14:54	coopernurse	technomancy: agreed. JS is a bizarre language. but there's a ton of client side developers who have gotten good at it, and want to use those skills on the server
14:55	Cozey	Uff. this means we'll not all be forced to leave lisp and code JS .... :P Thanks for the opinions, gotta go. good night!
14:56	qed	JavaScript in general is like Ke$ha barfing glitter.
14:56	manutter	ew
14:56	qed	:D$&#^&^$#&^$# <--example
14:56	dnolen	qed: problem is that JS neighter as bad as people say (Java people who don't know anything) nor as good (JS koolaid drinkers)
14:56	dnolen	s/neighter/neither
14:56	sexpbot	<dnolen> qed: problem is that JS neither as bad as people say (Java people who don't know anything) nor as good (JS koolaid drinkers)
14:56	edw	technomancy: That most languages insist on that statement/expression distinction is baffling to me.
14:57	qed	dnolen: agreed.
14:57	coopernurse	it has some serious issues for anyone writing anything nontrivial
14:57	Pisketti	Coming from a Java background, having everything as expressions is wonderful
14:57	coopernurse	error propegation in async code, for example
14:58	amalloy	qed: i saw a good tweet on that topic: "I think the most common complain about javascript is 'Help, this language is bullshit!'"
14:58	coopernurse	I haven't explored Clojure's promise implemenation yet
14:58	coopernurse	so I'm curious how it solves that
14:59	coopernurse	I'm still reversing a list :P
14:59	qed	amalloy: heh
14:59	amalloy	~source promise
15:00	pjstadig	http://twitter.com/#!/fogus/status/57082438286979072
15:01	coopernurse	great quote
15:01	edw	Is there an X analog to VNC?
15:01	coopernurse	edw: X itself is a network protocol
15:01	imade	why (comment ...) cannot contain : character? https://gist.github.com/989395
15:01	edw	Er, an X analog to screen?
15:02	coopernurse	edw: hmm.. that I don't know
15:02	wastrel	xdmcp
15:02	wastrel	screen?
15:02	amalloy	(comment) is misleading and evil
15:02	wastrel	iono
15:02	clojurebot	paredit screencast is http://p.hagelb.org/paredit-screencast.html
15:02	ataggart	imade: because the comment form is still read by the reader.
15:02	gfrlog	amalloy: why?
15:03	technomancy	clojurebot: what are you insinuating there
15:03	clojurebot	Titim gan éirí ort.
15:03	ataggart	imade: if you want the reader to ignore the form, use the #_ reader macro
15:03	amalloy	&(comment TODO: do some stuff)
15:03	sexpbot	java.lang.Exception: Invalid token: TODO:
15:04	amalloy	&(inc (comment make one bigger) 1)
15:04	sexpbot	java.lang.IllegalArgumentException: Wrong number of args (2) passed to: core$inc
15:04	edw	coopernurse: I want to be able to keep an X client going forever and simply re-connect my server to it.
15:04	imade	I see, ok, I will investigate this #_ macro then
15:04	edw	There must be some sort of X proxying app.
15:04	amalloy	gfrlog: ^
15:04	dnolen	&(comment ; foobar)
15:04	sexpbot	java.lang.Exception: EOF while reading
15:05	coopernurse	edw: gotcha. I don't know how to do that
15:05	ataggart	,#_(does not get read)
15:05	clojurebot	EOF while reading
15:05	gfrlog	amalloy: (comment) is misleading and evil
15:05	dnolen	imade: comment is fine, but you can't just have random text lying around in it, you need to to preface non sexpr lines with ;. It's still the most convenient way to block out code you don't want to get recompiled when developing, at least for me.
15:06	gfrlog	dnolen: what about #_?
15:06	ataggart	dnolen: can you think of a reason to use comment over #_ ?
15:06	TimMc	comment can take multiple forms
15:06	TimMc	So use #_(comment ....) :-)
15:07	gfrlog	TimMc: or just #_(....)
15:07	TimMc	gfrlog: Erk, yes,
15:07	dnolen	just personal preference, I use #_ to remove single exprs wedged in code, (comment ...) for blocks of various code I'm playing around with.
15:09	gfrlog	I agree that the name is misleading. Maybe (ignore) would be better. "comment" already means something specific that (comment) isn't
15:11	dnolen	ah #_ is effed up in SLIME, that's why I avoid it
15:11	dnolen	both for formatting and evaluation
15:12	edw	dnolen: I do the same (or similar): COMMENT for things like test or exercise code, #_ for individual expressions I don't want to be eval'd.
15:14	amalloy	dnolen: really? how do you find it messed up for evaluation?
15:14	ataggart	speaking of contains?, if I could go back in time, I'd have sets act as predicate fns, create a new fn called get? which behaves like current contain?, and change contains? to do what most people think it should do.
15:14	dnolen	#_(+ 4 5)^ C-x C-e -> 9
15:14	amalloy	sure. i would be astonished if it traveled back past that sexp to the first one that's not commented
15:14	TimMc	dnolen: Ah, it doesn't go back far enough?
15:15	amalloy	that is, i think the existing behavior is useful for "does this code i've commented out still work", and some other behavior would be useful for "oh shit i wanted to test this commented-out code, not that delete-the-db function before it"
15:17	dnolen	amalloy: not disagreeing I use #_ when I want to test multiple possible values for an expr in an existing expr, I put snippets of test code in (comment ...)
15:19	amalloy	incidentally i don't think it would be possible to make slime understand #_ without a huge effort
15:22	edw	I use #_ extensively and I've never been bitten by this. Do you really see "(foo) #_ (apocalypse)\|", type C-x C-e and expect the foo combination to be evaled? That's crazy.
15:23	dnolen	edw: I did say personal pref :) it affects movement and paredit as well
16:04	timvisher	hey all
16:04	timvisher	i'm using clojure.contrib.shell-out to interact with imagemagick
16:04	timvisher	when I get to an image that has bad data in it, my program just hangs
16:05	timvisher	i remember from my groovy days that if you don't properly consume output, you can get into this situation, but i can't find anything in the docs indicating how to consume the error stream
16:05	timvisher	thoughts?
16:06	ataggart	try clojure.java.shell
16:10	technomancy	dnolen: harder than you think as it would probably involve forking slime
16:10	technomancy	since I don't think upstream would be too keen on the feature
16:11	timvisher	ataggart: whoo! that seems to have done it. thanks!
16:12	timvisher	btw, when programming in slime, i find myself wanting to get a clean version of my namespace, i.e. wipe out all references and definitions and then reload them
16:12	timvisher	the way i do this is to kill the swank server and then restart it
16:12	pdk``	slime
16:12	timvisher	is there a better way to do that?
16:12	pdk``	clean
16:12	pdk``	wipe
16:12	pdk``	HMMMMMM
16:12	clojurebot	Cool story bro.
16:13	technomancy	timvisher: you can do ns-unmap or remove-ns, but there's nothing exposed from elisp. there should be though.
16:13	TimMc	clojurebot: botsnack
16:13	clojurebot	thanks; that was delicious. (nom nom nom)
16:13	pdk``	have you considered using im4java through clojure
16:14	timvisher	pdk``: i was looking into JMagick but they don't appear to be available through maven/clojars
16:15	timvisher	i then figured that if I was going to bother shelling out through im4java, i want to do something so simple that there has to be an easy way to simply shell out
16:15	timvisher	so far, this is really all I want to do
16:15	timvisher	if I need more from imagemagick, i might go with im4java
16:15	timvisher	jmagick seems... poorly documented
16:17	timvisher	technomancy: I suppose I could effectively switch to the user namespace, (remove-ns whatever-ns) at the repl, and then switch back to the buffer and C-c C-k again.
16:21	technomancy	beware that remove-ns can screw up downstream consumers though
16:21	technomancy	actually ns-unmap may as well
16:21	technomancy	one way to find out
16:32	amalloy	timvisher: you could bind that sequence of commands to a key and just use that
16:36	timvisher	amalloy: indeed I could. 'nother day though. I can now generate thumbnails for my image seq. hooray! :)
16:36	timvisher	thanks for the awesome help as always ladies!
16:38	offby1	laddies?
16:39	timvisher	no, i meant ladies
16:39	timvisher	i was going to say gentlemen
16:39	timvisher	then i realized there may be ladies present
16:39	timvisher	then I felt like sticking it the old masculine general pronouns and just call us all ladies
16:39	timvisher	:)
16:40	timvisher	hopefully no one's offended, as I don't think i'd make much progress with clojure if I had to stop coming here
16:43	offby1	how dare he
16:43	offby1	yeah
16:43	__name__	I've been longing for something to feel offended about all day.
16:44	__name__	Oh. Wait. That's not how it works, is it?
16:44	amalloy	offby1: i admire the way you immediately turned a vicious personal attack into an opportunity to profit through merchandising
16:45	timvisher	offby1's got class
16:52	Pisketti	I wonder if there are any _real_ ladies here.
16:54	amalloy	good call there
16:55	pjstadig	i'm a dog
16:55	pjstadig	http://www.unc.edu/depts/jomc/academics/dri/idog.jpg
18:05	brian_	FYI - I created an s4code git repo that contains all the other repos as submodules for easy cloning/updating/etc
18:06	brian_	oops, wrong chat!
18:15	VT_entity	Hey all
18:15	VT_entity	I've got a question.
18:16	VT_entity	I'm trying to use cycle to produce an infinitely repeating collection. I want to use vectors because I think they will be faster
18:16	VT_entity	(def ringbuffermembers [1 2 3 4 5])
18:16	VT_entity
18:16	VT_entity	(def ringbuffer (cycle ringbuffermembers))
18:17	VT_entity	this works, but if I do
18:17	VT_entity	(take 20 ringbuffer)
18:17	VT_entity	it returns a list
18:17	VT_entity	not a vector
18:17	amalloy	vectors aren't lazy
18:17	amalloy	you can't have a lazy vector
18:17	amalloy	(also, it returns a seq, not a list; the repl renders them both as (a b c))
18:17	VT_entity	so... duck typing is turning my vector into a list because I'm treating it lazily?
18:18	VT_entity	ooooh
18:18	amalloy	&(class (take 1 (cycle [1])))
18:18	sexpbot	⟹ clojure.lang.LazySeq
18:18	amalloy	you can use a vector if you want, but cycle will take a sequence view on it anyway
18:18	amalloy	and return a sequence
18:19	VT_entity	yeah, I couldn't figure out why
18:19	no_mind	using enlive, I have selected a node of tag type :select . Now I want to iterateover all teh optin tags under selected select node and set one of the option nodes as selected. How do I do this ?
18:19	amalloy	&(seq [1 2 3])
18:19	sexpbot	⟹ (1 2 3)
18:19	raek	a seq is just a sequential view of some abstract collection, which can be infinite
18:19	raek	...and not really a data structure, in a sense
18:20	raek	no_mind: at?
18:20	VT_entity	I'm trying to figure out whether its faster to do this with lists or vectors
18:20	amalloy	neither, really
18:21	amalloy	i mean, you might notice a slight difference
18:22	VT_entity	I'm still learning the language. I figured vectors might be faster because I might eventually be creating a lot of these ringbuffers
18:22	amalloy	and if you did, lists would probably be the winner in this particular contest, but i'm just guessing
18:23	VT_entity	maybe do it with pvec
18:23	VT_entity	ah, thanks
18:23	amalloy	&(doc pvec)
18:23	sexpbot	java.lang.Exception: Unable to resolve var: pvec in this context
18:23	VT_entity	ah, I guess I forgot the mnemonic for parallel vector
18:24	amalloy	VT_entity: i don't understand what you're talking about. parallel vector?
18:24	raek	VT_entity: are you concerned about whether (cycle [1 2 3]) or (cycle (list 1 2 3)) is the most efficient?
18:24	VT_entity	lol, yes
18:24	VT_entity	I am an utter noob, sorry
18:25	amalloy	VT_entity: there are 10,000 more important things to worry about when you're learning a language. ask this question again once you've covered them all :)
18:25	VT_entity	I am going to be invoking a whole bunch of these ringbuffers and popping functions off of them
18:25	raek	if so, it must be hard for you to get anything done if you spend your time doing these (premature) micro-optimizations all the time
18:26	VT_entity	it's going to be pretty intense
18:26	amalloy	VT_entity: madness
18:26	amalloy	stop worrying about it
18:26	VT_entity	I'm building an artificial life game
18:26	raek	VT_entity: if a queue is what you need, there is a data structure in Clojure for that too
18:26	amalloy	so what? if you find out this is the bottleneck, you can change it later
18:27	VT_entity	ah, that's a smarter way to go about it.
18:27	amalloy	(cycle foo) will return a lazy-seq no matter what foo is, so the consumer won't care
18:27	no_mind	raek: no luck http://pastebin.com/KZ1jHJV1
18:27	VT_entity	&(doc queue)
18:27	sexpbot	java.lang.Exception: Unable to resolve var: queue in this context
18:28	amalloy	&(doc seque) i think?
18:28	sexpbot	⟹ "([s] [n-or-q s]); Creates a queued seq on another (presumably lazy) seq s. The queued seq will produce a concrete seq in the background, and can get up to n items ahead of the consumer. n-or-q can be an integer n buffer size, or an instance of java.util.concurrent B... http://gist.github.com/989895
18:28	amalloy	clojure's seq isn't very well polished afaik though
18:28	VT_entity	aaah
18:28	VT_entity	thanks
18:30	raek	no_mind: the problem with your code is that in the "transformation slot" of the outer html/at form, you don't put a transformation function
18:37	raek	no_mind: you need to turn (html/at <some node> [:option] abc) into a function that takes a node and returns the changed node
18:41	no_mind	k
18:41	no_mind	raek: we need a short book to explain the concepts of enlive :)
18:42	raek	no_mind: most of enlive is actually ordinary clojure
18:42	no_mind	wellclojure is not ordinary :)
18:42	raek	no_mind: what you put in the "transformation slot" of an 'at' form is just an ordinary clojure expression, and follows ordinary evaluation rules
18:44	raek	no_mind: I assume you come from a programming language where functions are not values?
18:45	no_mind	raek: but that still leaves the original problem unsolved. How to iterate over each option tag and set a tag value as selected ? From what I see, 'at' will select all the option tags
18:45	raek	no_mind: at will only operate on the tree that you give it
18:46	raek	no_mind: in your case, the outer at should pass the select element subtree to the inner at
18:47	raek	I assume you want to iterate over all the option elements of that select element
18:48	no_mind	raek: yes iterate over al elements and set one option as selected
18:51	raek	at works by matching nodes with selectors. on a match, it will pass the matched node (and its subnodes) to the corresponding transformation function.
18:52	raek	(at (html-snippet "<p><b>foo</b></p>") [:b] (fn [node] (prn node) {:tag :i, :content ["bar"]}))
18:52	dnolen	is it not possible to install swank-clojure via marmalade?
18:53	raek	dnolen: swank-clojure or swank-clojure.el?
18:53	dnolen	raek: used to install swank-clojure via ELPA, wondering if marmalade is the new way to go, has more packages, and seems more up-to-date.
18:54	raek	dnolen: the swank-clojure you probably want to use is not an emacs library
18:55	raek	there is an old lib called swank-clojure.el from the times before Leiningen, but it was hard to use since you needed to configure the classpath (so switching betsween projects was a pain)
18:56	raek	dnolen: http://technomancy.us/149
18:56	raek	dnolen: either add [swank-clojure "1.3.1"] to your project.clj or run "lein plugin install swank-clojure 1.3.1"
18:57	hiredman	dnolen: does core.logic provide a cond like macro for conditional execution based on matching?
18:58	raek	no_mind: in that example, the transformation function receives {:tag :b, :content ("foo")} and returns another tree ("<i>bar</i>"). it also prints the original tree
18:58	no_mind	raek: http://pastebin.com/CFZ1LAuk it prints the whole node including the html. Whereas what I want in function xyz is bunch of :option tags only
18:58	raek	no_mind: in your case, you probably want to write something like (fn [node] (at node ...selector... ...transformation))
18:59	dnolen	hiredman: yes, conde is the primitive form, defne gives you pattern matching sugar. It's a bit different from Prolog tho since in Prolog different clauses can be defined top-level, in core.logic matching is local to fns (goals) - kinda like Clojure multi-arity fns. Hope that makes some sense. I need to document more.
19:01	hiredman	and you wrap it in the whole run* thing?
19:03	raek	no_mind: it doesn't print the whole tree, it prints nil. the at expression returns the whole tree, though
19:03	carllerche	Is there a way to determine the arity of an arbitrary (anonymous?) function?
19:05	dnolen	hiredman: yup, run* is basically a sort of monadic thing, it threads an environment through your logic statements, it return a lazy-seq of answers.
19:06	raek	no_mind: sorry, actually it doesn't print anything at all. the selector does not match, somehow
19:06	dnolen	goals are really just closures that take an environment manipulate it (possibly replicate it) and pass it on to the next goal.
19:06	no_mind	raek: how come ?
19:06	dnolen	(== q true) -> (fn [a] (unify a q true))
19:07	dnolen	so I guess run* is sort of like do in Haskell.
19:09	raek	no_mind: strange, it works with (content "BOO") instead of xyz...
19:10	raek	dnolen: technomancy's recent blog post is the way to go. the previous approach (pre "clojure-jack-in") is here: http://dev.clojure.org/display/doc/Getting+Started+with+Emacs
19:11	raek	no_mind: (defn xyz [node] (prn node) node) works as expected...
19:12	no_mind	raek: the selctor for select tag is working, i checked by doing a set-attr instead of xyz and it works
19:12	amalloy	carllerche: no
19:13	raek	the printing seems to mess it up...
19:14	amalloy	mainly because functions can have multiple arities, and that information only really exists in the var's metadata (which anonymous function don't have) once the compiler's read it in
19:15	no_mind	raek: no luck here.. I am still getting the same result
19:15	carllerche	amalloy: there seems to be getRequiredArity it seems
19:16	amalloy	&(-> + var meta :arglists)
19:16	sexpbot	⟹ ([] [x] [x y] [x y & more])
19:16	amalloy	if you have an actual var object, you can work with that to see what it accepts
19:16	carllerche	that doesn't really help though
19:16	raek	no_mind: oh, now I get it! it actually works, but prn is called in the middle of the printing of the result!
19:16	amalloy	no
19:16	carllerche	amalloy: yeah, i'm working with anonymous functions :(
19:16	raek	try this: (html/at rr [(html/id= "one")] (fn [node] (prn "BEGIN") (prn node) (prn "END")))
19:16	amalloy	whose arities you don't know, but need to know? that seems like a bad design choice
19:17	carllerche	amalloy: it's mostly for convenience helpers during testing
19:17	amalloy	i don't think that message has much information in it :P
19:18	carllerche	it's not a big deal, it's mostly so that I can write tests w/o _ everywhere, but whatever.. worth a shot
19:18	raek	no_mind: due to laziness, the transformation won't be call until needed, which happens to be in the middle of the printing of the expression
19:18	no_mind	raek: ok butI am still receiving the complete html in prn whereas I want only option tags
19:19	raek	no_mind: take a look at this: (def a (atom nil)) (defn xyz [node] (reset! a node))
19:19	raek	no_mind: evaluate (html/at rr [(html/id= "one")] xyz) and then look at the value of a
19:20	raek	no_mind: the interleaved printing confused the matter
19:22	raek	no_mind: to answer your original question: (html/at rr [(html/id= "one")] #(html/at % [:option] abc))
19:22	raek	no_mind: do you see why this works?
19:24	no_mind	yaa
19:30	technomancy	what could cause a simple (clojure.java.shell/sh "ls") call to cause the JVM to never exit?
19:31	technomancy	adding shutdown-agents fixes it, but that's ridiculous
19:32	technomancy	there are a few futures in clojure.java.shell/sh, but they're all deref'd by the time the function returns
19:33	hiredman	technomancy: sh uses futures, which spins up the agent threadpool, etc
19:33	hiredman	the jvm waits for live threads to exit before exiting
19:33	technomancy	even with no active futures?
19:33	hiredman	after the futures finish they are returned to the threadpool, and are still "live"
19:33	hiredman	waiting to be reused
19:34	hiredman	(kind of what a threadpool is for)
19:34	technomancy	makes sense if the process isn't trying to exit
19:34	hiredman	which is why shutdown-agents was added
19:35	technomancy	shutdown-agents is permanent though
19:35	hiredman	the other option is to make the threadpool threads daemon threads
19:35	technomancy	useless for writing composable code without a corresponding startup-agents
19:35	hiredman	correct
19:36	technomancy	the JVM is getting revenge on me for having ported a 75-line clojure file to a 30-line shell script
19:36	hiredman	http://tech.puredanger.com/2010/06/08/clojure-agent-thread-pools/
19:37	technomancy	"If you really loved me, you wouldn't want to shell out! I've got everything you need right here. Come baaaaaaack..."
19:37	hiredman	I kind of agree with the blog post, not making the threadpool threads daemon threads by default is kind of a drag
19:37	technomancy	I wouldn't mind one bit if I could reset the thread pool
19:38	no_mind	raek: calling set-attr in xyz is throwing error
19:39	scgilardi	given that you can't recover from shutdown-agents, I wonder if arranging for a call to shutdown-agents in a shutdownhook would be appropriate. (Runtime.addShutdownHook)
19:40	raek	no_mind: what error?
19:40	technomancy	scgilardi: whoa; shutdown hooks.
19:40	technomancy	that looks like the Right Thing
19:41	hiredman	they won't run until the threadpool threads stop
19:41	hiredman	"The program exits normally, when the last non-daemon thread exits or when the exit (equivalently, System.exit) method is invoked, or "
19:41	technomancy	ಠ_ಠ
19:41	scgilardi	Isn't a successful System/exit what we're after?
19:42	technomancy	in this case System/exit would break composability as well
19:42	hiredman	unless lein did some kind of "run these tasks then call System/exit"
19:43	hiredman	(which it must, come to think of it)
19:43	hiredman	to return exit codes
19:43	scgilardi	inc
19:43	technomancy	it only calls System/exit on failures
19:43	technomancy	but it probably should either way
19:45	no_mind	raek: java.lang.IllegalArgumentException: Don't know how to create ISeq from: net.cgrand.enlive_html$set_attr$fn__696
19:46	raek	no_mind: all I can tell from that is that you have put the (set-attr ...) call in the wrong place...
19:47	raek	no_mind: could you explain the surrounding code?
19:48	no_mind	raek: http://pastebin.com/DLVbMw2F
19:51	raek	no_mind: first: use = instead of .equals
19:52	raek	no_mind: second: you are calling set-attr wrong. remember the "two stage" thing?
19:53	raek	and you are missing the else expression of the if
19:53	raek	which should return the node unchanges
19:53	raek	-d
20:01	raek	no_mind: anyway, here's my approach: https://gist.github.com/990033
20:03	no_mind	raek: thnxs, i fixed that
20:07	tomoj	clojurebot: single segment namespaces?
20:07	clojurebot	single-segment namespaces is unsupported. (foo instead of foo.core) they may work in a few circumstances, but you shouldn't rely on them.
20:07	tomoj	but why, clojurebot?
20:09	amalloy	tomoj: default package
20:10	tomoj	ah
20:10	tomoj	so e.g. osc-clj has (ns osc)
20:11	tomoj	that means if there is a java lib out there with an "osc" class in the default package, they clobber?
20:12	amalloy	i don't think that's the only issue
20:30	dnolen	when I try clojure-jack-in it says it can't find lein, how can I set the path to lein?
20:33	technomancy	dnolen: gui-launched emacs on OS X?
20:33	dnolen	technomancy: yeah
20:33	technomancy	yeah, your .profile is being ignored =\
20:33	dnolen	do I just (setq clojure-swank-command ...) ?
20:33	technomancy	there's some XML plist you have to edit
20:34	technomancy	to set your $PATH for GUI apps
20:34	technomancy	it's ridiculous
20:34	dnolen	technomancy: got a link?
20:34	technomancy	dnolen: actually clojure-swank-command would work too
20:35	technomancy	but you would still have trouble with non-swank commands like with magit
20:35	technomancy	maybe this? http://www.emacswiki.org/emacs/MacOSTweaks#toc11
20:36	scgilardi	http://developer.apple.com/library/mac/#qa/qa1067/_index.html
20:36	technomancy	that's specific to emacs rather than all gui-launched programs; maybe it's good enough
20:38	technomancy	ooh; a non-xml version. slightly less awful!
20:38	technomancy	that is probably the #1 most common problem people have with Emacs on any platform. probably should mention it in the swank readme.
20:39	technomancy	(apart from "zomg the parens" of course)
20:39	scgilardi	well, it's a gui on the xml. and comes with apple's developer tools.
20:39	jedi	ah that would explain my problem with it too
20:40	dnolen	technomancy: how long should jack in take? I see that it's pasting slime.el into swank buffer...
20:41	technomancy	dnolen: maybe 5-10 seconds on the server JVM?
20:41	dnolen	technomancy: hmm I should get a REPL ?
20:41	dnolen	technomancy: I tried jack in from the dired view of my project.
20:42	technomancy	that oughtta work; is it just stalled?
20:42	technomancy	what's at the end of the swank buffer?
20:43	scgilardi	example environment.plist: https://gist.github.com/990084
20:44	dnolen	technomancy: swank looks stalled on line 10000 something.
20:45	dnolen	technomancy: I used: lein install plugin swank-clojure 1.4.0-SNAPSHOT, and trying to jack into a 1.3.0-alpha7 project.
20:46	technomancy	dnolen: I haven't used it with clojure 1.3 but have seen reports of it working. what's the content at the end of the buffer?
20:46	dnolen	technomancy: it just keeps freezing around line 10937: it's in the middle of pasting "slime-repl-current-input"
20:47	dnolen	lein jack-in 36863: exited abnormally with code 1.
20:47	dnolen	in Messages
20:47	technomancy	freezing mid-function? that's odd; I haven't heard of anyone else getting that.
20:48	dnolen	I will say the slime.el paste it very slow, I see it scroll by
20:48	dnolen	s/it/is
20:48	sexpbot	<dnolen> I will say the slime.el paste is very slow, I see is scroll by
20:48	technomancy	if you already have slime installed, you can stick with lein swank + m-x slime-connect
20:48	technomancy	this is really more of a convenience for people who haven't gone through the setup process yet
20:49	technomancy	I am curious what's going on though
20:49	dnolen	technomancy: can you grab files from marmalade and ELPA ?
20:50	technomancy	yeah, you should be able to use curl or whatever
20:50	technomancy	they're also inside the swank-clojure jar
20:51	dnolen	technomancy: won't installing package.el from ELPA override marmalade package.el?
20:52	technomancy	you mean using package.el to upgrade itself?
20:52	technomancy	I'm not sure; I don't think the elpa version has a higher version number
20:55	dsop	is it true that I cannot access the cached collection inside a lazy-seq body?
20:55	dsop	so something like (lazy-seq (let [x (seq coll)] ... (count x)...)
21:03	dnolen	technomancy: so swank-clojure is not something I should install from ELPA right?
21:10	dnolen	Emacs is not for the faint of heart ...
21:10	hiredman	dnolen: core.logic run on 1.2?
21:11	dnolen	hiredman: I'd like it to but I haven't had time to sort out what needs to be fixed.
21:11	dnolen	hiredman: I ran into some weird errors and did not pursue. There no reason for core.logic to be 1.3 centric.
21:16	dnolen	after much teeth gnashing, animal sacrificing, I have a working Clojure Emacs setup again and I can get packages from Marmalade and ELPA.
22:03	dnolen	hiredman: OK looked at it a little, here's a real bug in 1.2.1 that prevents core.logic from working https://gist.github.com/990176
22:07	dnolen	if anyone knows how to work around this one, I'll be happy to fix core.logic to work w/ 1.2 now.
22:17	hiredman	dnolen: https://gist.github.com/990194
22:18	dnolen	hiredman: will that be slow? core.logic really relies on very fast map lookups.
22:19	hiredman	the other option is make Foo the full package qualified name
22:20	TimMc	arglbalrlgrl
22:20	hiredman	basically Foo is resolved to the wrong classname at compile time (it is resolved to the stub the compiler generates)
22:20	TimMc	I did my first serious Java coding today since... about a year ago.
22:20	TimMc	I REALLY want macros.
22:20	amalloy	haha TimMc i was gonna ask if it was java-related
22:20	TimMc	of course
22:21	amalloy	TimMc: well, it could be php-related
22:21	dnolen	hiredman: yeah tried fully qualified name, got classloader error.
22:21	dnolen	attempted duplicate class definition for name
22:22	hiredman	bleh
22:22	hiredman	stupid deftype bugs in 1.2
22:27	dnolen	hiredman: difference is pretty dismal, w/ resolve in 1.2 you're looking at 600ms for 1e7 iterations, 1.3 7-9ms if I can do the real instance check.
22:28	dnolen	core.logic is constantly reaching into the map to check vars, add vars, etc. so equal needs to really cost near nothing.
22:29	hiredman	I may noodle on it
22:30	dnolen	hiredman: if you come w/ something let me know, I think this is the weird issue I saw, probably the only real bug, but of course it breaks everything.
22:31	amalloy	dnolen: (let [this-class (atom nil)] (deftype Foo [] (equals [this other] (instance? this-class other))) (reset! this-class Foo)) perhaps?
22:31	dnolen	amalloy: not really willing to do something like that.
22:31	dnolen	I'll mention this on the dev ML
22:39	mefesto`	dnolen: this works for me on clojure 1.2.0: https://gist.github.com/990219
22:40	mefesto`	not sure if it meets your performance requirements but atleast it returns true :)
22:42	dnolen	mefesto`: huzzah! and it's even faster it seems!, k will see if that fixes core.logic in a few, gotta run for a bit.
22:59	amalloy	KirinDave: i found an entry in the #clojure logs where you talk about http if-modified-since. is there a compojure wrapper that handles that already (for static file-based routes), or would i have to write it myself? so far i can't even figure out how to convince the client to send an If-Modified-Since header
23:00	KirinDave	amalloy: I dunno if there is a compojure wrapper. I doubt it?
23:00	KirinDave	amalloy: Which client?
23:01	amalloy	KirinDave: neither chrome nor firefox seem to be sending that header afaict
23:01	KirinDave	amalloy: Oh
23:01	KirinDave	I dunno about it.
23:01	KirinDave	I see it usually in the context of proxies
23:02	KirinDave	I don't know how you'd provoke Chrome or Firefox.
23:03	amalloy	KirinDave: i thought most clients were keeping a local cache and would involve the server in a decision whether or not updating was needed
23:04	KirinDave	amalloy: Offhand I'm not sure what they do.
23:04	amalloy	KirinDave: looking at the headers when i request google.com a few times, it looks like mostly google says "this data is good for N seconds, don't even ask me if it's changed". but for at least one resource, they convince chrome to include If-Modified-Since
23:55	dnolen	core.logic is now compat w/ 1.2
23:56	mefesto`	very cool. now i just need to learn about this thing they call "logic"
23:58	technomancy	Licenser: ping