#clojure – 2014-09-14

2014-09-14

00:20	john2x	cider doesn't automatically load all namespaces defined in a project? Unlike in `lein repl`, where all the project's namespaces are immediately available?
01:08	amalloy	john2x: uh, lein repl doesn't autoload all your namespaces either. it autoloads the namespace you mark as :main in project.clj, if you set a :main at all. that namespace often transitively loads other namespaces, but that's up to you
01:13	john2x	amalloy: ah I think I mean 'evals' the namespaces.. it seems in cider, I have to eval a file before I can require it?
01:13	amalloy	no you don't. you can require files whenever you want
01:15	john2x	ah right. silly me. I was relying on company-mode to list all available namespaces..
05:57	SagiCZ1	is there a paredit command that swaps first expressions in sexps like this?
05:57	SagiCZ1	(foo1 (foo2 x)) --> (foo2 (foo1 x))
05:58	SagiCZ1	no amount of slurping or barfing does this
06:12	amalloy	SagiCZ1: paredit-convolute-sexp
06:13	amalloy	if you put point between foo2 and x
06:57	cfleming	amalloy: What does convolute-sexp actually do? Just swap the two head symbols?
06:58	cfleming	amalloy: I've never found a good explanation of what it does.
07:03	cfleming	Actually, I see - the smartparens doc has a better explanation: Move the expressions before point in the current list before the enclosing list.
08:30	SagiCZ1	cfleming: we dont have that paredit command in Cursive do we?
08:31	cfleming	SagiCZ1: No, but now I know how it should work I can implement it.
08:33	SagiCZ1	cfleming: alright, great.. not a major feature but it would be nice to have
08:37	cfleming	SagiCZ1: No doubt, I've wanted it from time to time (now that I know what it actually does)
08:42	gaverhae	Hi all! Has anyone got any experience with ClojureScript/React on Android?
09:56	favetelinguis	Why am not my pre condition firering if i call (straights 1) http://lpaste.net/111034
09:59	gaverhae	favetelinguis: What's the definition of "deck" ?
09:59	favetelinguis	[A 2 3 4 5 6 7 8 9 T J Q K]
10:00	favetelinguis	i want to only be able to call this function with values 2-5
10:01	gaverhae	favetelinguis: I get: (straights 1) AssertionError Assert failed: (and (> num-cards 2) (< num-cards 6)) stra.core/straights (form-init7754222051149817257.clj:1)
10:01	gaverhae	favetelinguis: What's your Clojure version? Any idea what JVM options you've passed? Did you disable assertions in your project.clj?
10:02	favetelinguis	running in lighttable insta repl
10:02	gaverhae	favetelinguis: If clojure.core/assert is false when the defn form is compiled, pre/post condition code will not be generated
10:02	favetelinguis	hmm how can i check that value?
10:04	favetelinguis	looks like it us true
10:12	gaverhae	favetelinguis: You need to check its value at compile time, so something like putting (println assert) at the top level
10:14	favetelinguis	does the function overall make sense for you? im a clj nood and found cycle to be perfect to represent straights in poker
10:14	favetelinguis	the let statement is just placeholder and does nothing
10:19	gaverhae	favetelinguis: I don't know anything about poker; other than that it looks fine. I'd only note that < and > in Clojure cna take multiple arguments, so you could replace (and (> num-cards 2) (< num-cards 6)) with (< 2 num-cards 6)
10:19	gaverhae	favetelinguis: Oh, and the local binding "cards" is unused, so you could remove it.
10:26	favetelinguis	ok ty
11:22	perplexa	hey
11:23	perplexa	i'm trying to use midje with leiningen in only one specific project. i don't want to add it to my global profiles.clj but rather project.clj and i don't see the midje task in leiningenm.
11:24	perplexa	i added the following to my project.clj: :dev {:dependencies [[lein-midje "3.1.3"]
11:24	perplexa	[cascalog/midje-cascalog "2.1.1"]]}}
11:24	perplexa	anything else i'm missing?
11:25	clojer	Can anyone explain how eval-ing forms in a core.cljs file works when using a Weasel browser repl? Nothing I eval in this file makes any difference to the connected browser (Chrome).
11:25	perplexa	regarding my question, i found out, it has to be in :plugins :P
11:25	clojer	I'm using Emacs (Live) 24/Cider 0.7
11:31	perplexa	/wg 24
11:41	guest889	اي عرب مهتمين بكلوجر؟
11:55	ethan_	/msg NickServ IDENTIFY cjs-emacs
12:50	johnwalker	anyone doing clojurecup? i am looking for a team
12:55	ro_st	is using future and future-cancel the correct way to start and stop threads in Clojure?
12:56	justin_smith	ro_st: future is good when the thread should run until it calculates some result, and you want to easily access that result
12:56	ro_st	i want to have a sleep loop run in its own thread but be able to kill that thread
12:56	ro_st	so that i can wrap it up in a reloaded Component
12:56	justin_smith	ro_st: future-cancel only works if the future hasn't started yet, or it checks if its thread is interrupted and acts on that
12:56	ro_st	i thought maybe to use agents but there's no way to stop one
12:57	ro_st	should i just interop with java?
12:57	justin_smith	no
12:57	ro_st	what should i use?
12:57	justin_smith	if you don't need a derefable result, you can pass an fn of no args to (Thread. f)
12:57	dbasch	ro_st: have a shared flag, and have the thread check the flag and exit if set
12:57	justin_smith	if you want it to be cancellable, you need to make it check for cancellation
12:58	ro_st	ahhh
12:58	ro_st	i'll try this. thank you
13:12	ro_st	what do i use to exit the thread?
13:12	ro_st	just return?
13:13	justin_smith	ro_st: put an if or when around your recur
13:13	justin_smith	if you are looping via recur (as you should)
13:13	justin_smith	or, do (while (not (.isInterrupted (Thread/currentThread))) ...)
13:13	justin_smith	there should really be a shortcut for that
13:17	ro_st	got it. thanks guys
13:23	irctc	hi, do you know how to filter all true results form a list such as (a b true c true d e f true) -> (a b c d e f)?
13:23	justin_smith	irctc: filter
13:23	irctc	yes but I don't know what function to filter with
13:23	justin_smith	,(filter #(= true %) '(a b true c true d e f true))
13:23	clojurebot	(true true true)
13:23	justin_smith	,(remove #(= true %) '(a b true c true d e f true))
13:23	clojurebot	(a b c d e ...)
13:24	irctc	ooh i see
13:24	justin_smith	sorry, first version was a serious thinko :)
13:24	justin_smith	short for thinkographical error, of course
13:25	irctc	can you link me to a reference for the % symbol? I come from clisp and it's something foreign for me
13:25	justin_smith	,(macroexpand '#(= true %))
13:25	clojurebot	(fn* [p1__79#] (= true p1__79#))
13:25	justin_smith	it's a shorthand for "first argument" inside the #() convenience macro
13:26	justin_smith	(fn [x] (= true x)) would be the same, it's just less friendly to read and write
13:27	irctc	thanks
13:27	justin_smith	the one gotcha with #(frob % %2 %3 %&) is that you can't nest more #() forms inside
13:27	justin_smith	because % would be ambiguous at that point
13:27	justin_smith	,(#(reverse %&) 1 2 3 4 5)
13:27	clojurebot	(5 4 3 2 1)
13:28	justin_smith	just for completeness' sake :)
13:30	irctc	oh I see
13:34	justin_smith	,(remove #{true} '(a b true c true d e f true))
13:34	clojurebot	(a b c d e ...)
13:34	justin_smith	sets can be used as predicates, this can be useful if you have some set of values to check
13:35	justin_smith	this fails of course if false and nil are values that should be matched
14:10	catern	are there any decent videos of Meta-Ex?
14:13	justin_smith	catern: have you seen what's linked from the official site? http://meta-ex.com/
14:14	catern	those are either sound-only recordings or just interviews
14:14	catern	i want to see them livecoding
14:14	catern	in fact, they should do a livestream
14:15	justin_smith	catern: first video, skip to the 15 minute mark
14:15	catern	(or the equivalent ofc)
14:16	catern	should I email them and request/suggest that they do a livestream? they've surely already thought of it...
14:19	catern	or perhaps not... little actually happens in the buffer, it seems
14:20	catern	or i guess the horrible cameraperson might just not be capturing it
14:22	catern	would be nice if instead of dirctly linking the hardware and supercollider or whatever, they linked hardware -> emacs buffer (-> overtone -> supercollider)
14:22	justin_smith	catern: that would be terrible
14:23	justin_smith	emacs does not to multithreading at all
14:23	justin_smith	adjusting two knobs at the same time would suck
14:23	catern	justin_smith: well, then it would be nice if they could do that
14:24	justin_smith	yes, I guess it would be nice if emacs was threaded. Don't hold your breath.
14:24	catern	well, even for the pretty-much-single-threaded things
14:24	justin_smith	sorry, I only get this grumpy because I wish emacs was usable for such things.
14:24	catern	instead of directly linking hardware -> supercollider, have the hardware modify the code
14:24	justin_smith	and I tried it extensively, and it only led to pain
14:25	justin_smith	a clojure process in the jvm can easily be connected to MIDI though
14:25	justin_smith	and you could use something like cider to update midi state in an emacs view I guess
14:26	justin_smith	or, better, update the state of the things MIDI is controlling in an emacs view
14:56	irctc	hi
14:56	irctc	I have this (incomplete) function
14:56	irctc	http://pastecode.org/index.php/view/64873765
14:57	irctc	and I want to keep doing the same, but calling ciclo once more in each extra line
14:57	irctc	however, the number of times I want to do that can't be known beforehand
14:58	irctc	how can I automate it?
14:59	justin_smith	what is the logic for when (ciclo x) becomes (ciclo (ciclo x))
15:00	irctc	(1 2 3 4) -> (4 1 2 3) -> (3 4 1 2)
15:00	irctc	I want to call it n-1 times
15:00	irctc	where n is the size of x
15:00	justin_smith	OK, but the first two elements call just ciclo
15:04	irctc	oh well I soul've added (take-nth 2 (emparejar equipos (ciclo(ciclo equipos)))
15:05	irctc	Ibut the issue still remains
15:05	justin_smith	oh, so you alternate calling with n+1 ciclo calls, and then take the rest
15:06	irctc	yes, (take-nth 2 (rest ... is just a way to take even-placed elements in the list
15:06	irctc	without the rest it takes odd ones
15:07	justin_smith	,((fn [els] (take (count els) (iterate (fn [l] (cons (last l) (butlast l))) els))) [0 1 2 3 4])
15:07	clojurebot	([0 1 2 3 4] (4 0 1 2 3) (3 4 0 1 2) (2 3 4 0 1) (1 2 3 4 0))
15:07	justin_smith	is that the result you expect?
15:08	corecode_	hi
15:09	corecode_	does the reader somehow retain location information, where a (sub)sexpr was read from? (file/line)
15:10	justin_smith	corecode_: it adds the file / line data to the metadata of vars
15:10	justin_smith	((juxt :file :line) (meta #'map))
15:10	justin_smith	,((juxt :file :line) (meta #'map))
15:10	clojurebot	["clojure/core.clj" 2586]
15:11	justin_smith	cd
15:11	justin_smith	silly mouse to focus
15:18	corecode_	justin_smith: thanks!
16:58	Solokeh	what is this room?
17:02	gfredericks	~clojure
17:02	clojurebot	clojure is the bestest programming language available.
17:02	gfredericks	$google clojure
17:02	andyf	~gfredericks
17:02	clojurebot	gfredericks is a DSL for seeding clojurebot with high-concept talk ideas
17:03	andyf	That last one is a joke. gfredericks appears fully human in person.
18:27	ggarciajr	hi all. I'm starting with clojure and I was wondering if anyone can help me with an issue I'm having.
18:28	danielcompton	ggarciajr: fire away. For future reference you don't need to ask to ask
18:31	augustl	hyPiRion: random slightly off topic question: how difficult would it be to have a custom memory allocator for c-rrb? I.e. my own GC, a ref counter, whatever.
18:34	hyPiRion	augustl: I started out with that, but it was too much overhead for the time period of my thesis. It's possible, but you'll have to locate all positions where the refcount increases and decreases (obviously).
18:35	augustl	hyPiRion: I see, tnx :)
18:35	hyPiRion	augustl: If it makes the library more suitable for whatever you need it for, file an issue and I'll have a look at it this week
18:36	augustl	hyPiRion: trying to find an AOT compiled environment with persistent data structures ;) Rust + c-rrb seems like a good option.
18:36	ggarciajr	Why this works -> (println (str "Tweets downloaded: " (count (map #(extract-tweet-data %) (:statuses (:body downloaded-data))))))
18:36	ggarciajr	And this doesn't? -> (let [downloaded-data (search-twitter query count since) tweets (map #(extract-tweet-data %) (:statuses (:body downloaded-data))) tweets-downloaded (count tweets)] (println tweets-downloaded))
18:36	augustl	apparently, the clojure community is the only one that can't live without persistent data structures?
18:36	hyPiRion	ah :)
18:36	hyPiRion	yeah, I'm pretty frustrated by the limited amount of persistent data structures in other languages
18:37	augustl	Go seems to say NOPE use message passing
18:37	ggarciajr	I get this error when trying to execute the second version -> actual: java.lang.ClassCastException: java.lang.Long cannot be cast to clojure.lang.IFn
18:38	augustl	apparently 4-16 core machines with shared RAM are going away very soon? ;)
18:38	hyPiRion	Go says no to generics :p
18:38	hyPiRion	Otherwise it'd be doable
18:39	augustl	ggarciajr: where does downloaded-data come from in the example that works?
18:39	augustl	ggarciajr: perhaps the values are different for downloaded-data in your two snippets
18:39	ggarciajr	it is downloaded from twitter using twitter-api
18:40	augustl	hyPiRion: if I can get c+rrb working in Rust, there's also https://github.com/michaelwoerister/rs-persistent-datastructures, and then I have everything i need :)
18:40	augustl	c-rrb*
18:40	ggarciajr	august1, they are comming from the same function. the data it just a map
18:42	ggarciajr	btw, tweets type is clojure.lang.LazySeq
18:46	raspasov	ggarciajr: how does extract-tweet-data look?
18:47	raspasov	can you put all your code in a github gist or something like that?
18:49	augustl	oh hey, https://github.com/BartoszMilewski/Okasaki
18:49	augustl	is there anything C++ doesn't have
18:49	brehaut	reason? clarity? determinism?
18:49	ggarciajr	(defn extract-tweet-data [tweet] {:id (:id tweet) :text (:text tweet) :user (extrat-screen-name (:user tweet))})
18:49	ggarciajr	(defn extrat-screen-name [user] (:screen_name user))
18:50	augustl	seems like C++ has no underlying concepts, just All The Features
18:52	raspasov	almost everything is possible in any language, it's really what the language makes idiomatic that counts
18:53	augustl	well, custom memory allocation is not possible in Clojure :)
18:54	raspasov	yes, almost :D
19:00	ggarciajr	found the problem. variable shadowing. count was being shadowed :(
19:00	raspasov	haha ok :) it happens
19:01	ggarciajr	thanks guys
19:01	raspasov	anytime you have a question you should post your whole namespace at least, someone with more experience would have spotted that right away
19:02	ggarciajr	thanks for the tip
19:02	raspasov	np :)
19:13	edipofederle	JOIN rubyonrails
19:16	locks	oops
19:16	edipofederle	hi
19:23	edipofederle	exit
19:23	edipofederle	\EXIT
19:23	edipofederle	QUIT
19:23	edipofederle	\QUIT
20:36	fUD	Helloo
21:29	johnwalker	campeterson: ping
22:08	normanrichards	hey
22:09	gfredericks	,'hi
22:09	clojurebot	hi
23:00	dee5	Is there any way to namespace qualify a symbol that was created/input to a macro?
23:26	clojurenoobie	hello!!
23:27	clojurenoobie	how goes the chat channel?
23:29	clojurenoobie	I am trying to write a function that given a string, will detect the indexes of a substring of vectors... Having some issues.
23:30	clojurenoobie	(map (detect-insubstring-function string-to-check-inside %)["item1" "item2" "item"]
23:30	clojurenoobie	I mean this seems like it would be really straightforward, but I keep keep getting errors...
23:31	clojurenoobie	I think python has made me a bit overreliant on string parsing magic...
23:31	clojurenoobie	any ideas?
23:31	falafel	clojurenoobie: I don't get your example, do you have some real world example of input and output
23:37	xeqi	,(map #(re-find #"\d" %) ["item1" "item2" "item3"])
23:37	clojurebot	("1" "2" "3")
23:37	xeqi	clojurenoobie: ^ ?
23:38	clojurenoobie	Yay, thanks
23:38	clojurenoobie	one other question, is there an elegant clojurish way to splite a string given a vector of indices?
23:39	clojurenoobie	I've got a function that works ok right now, but it's kind of ugly
23:44	justin_smith	clojurenoobie: what is a vector of indexes?
23:58	justin_smith	,((fn [s indexes] (map #(apply subs s %) (partition 2 1 (concat indexes [(.length s)])))) "chasefourdiamonds" [0 5 9])
23:58	clojurebot	("chase" "four" "diamonds")
23:58	justin_smith	that is at least a start