#clojure – 2010-07-26

2010-07-26

00:35	brehaut	presumably there is a library in clojure or contrib to make walking directories and files easy?
00:35	brehaut	(i also presume im not smart enough to have found it yet)
00:37	brehaut	ignore me, file-seq appears to be it
00:39	technomancy	file-seq is sweet
00:40	technomancy	daaku: things get added to Clojure, but there has only been one purposeful instance of breakage so far since 1.0
01:02	brehaut	does the #(... %) macro have any way to type hint the % outside of converting to an (fn ..) form ?
01:14	Bahman	Hi all!
01:56	vu3rdd	technomancy: ping
01:57	vu3rdd	technomancy: I am facing some problem with the lein if I compile the lein uberjar myself.
01:58	vu3rdd	any help to fix it will be great! I sent the error to the list a couple of days ago
01:58	daaku	technomancy: cool. that makes me hopeful :)
02:00	daaku	i just noticed i wrote this, and seemed like a common thing i write (the 3x get part): (nil? (get (get (get req :cookies) "fbc") :value)) -- is there a better way to write this? (things in the middle may be nil)
02:02	hiredman	(-> reg :cookies (get "fbc") :value nil?)
02:02	slyrus	vu3rdd: did you update lein recently? ISTR some uberjar bustage being fixed recently
02:02	daaku	hiredman: cool, thanks
02:03	OliverUv	(nil? (reduce #'get (req :cookies "fbc" :value)))
02:03	hiredman	OliverUv: this isn't common lisp
02:04	OliverUv	then implement reduce
02:04	hiredman	if you want to use a function in reduce you just use it
02:04	OliverUv	it is fairly straight forward
02:04	hiredman	(reduce get …
02:04	OliverUv	ah
02:04	hiredman	your list there at the end will be evaluated as a function call
02:04	OliverUv	oh yeah I just remembered, ? for scheme, p for cl
02:05	OliverUv	you are right about that too
02:05	hiredman	,(macroexpand-1 '(-> reg :cookies (get "fbc") :value nil?))
02:05	clojurebot	(clojure.core/-> (clojure.core/-> reg :cookies) (get "fbc") :value nil?)
02:05	OliverUv	oh damn, I was in #clojure, I thought I was in #lisp
02:05	OliverUv	sorry
02:06	hiredman	,(macroexpand-1 '(clojure.core/-> (clojure.core/-> reg :cookies) (get "fbc") :value nil?))
02:06	clojurebot	(clojure.core/-> (clojure.core/-> (clojure.core/-> reg :cookies) (get "fbc")) :value nil?)
02:10	cobol_expert	hi, what's the syntax for defn default parameter values?
02:10	cobol_expert	if there is one
02:11	dsantiago	There isn't one.
02:12	cobol_expert	dang
02:12	dsantiago	Though you could define multiple versions of the function with different arities that behave that way.
02:13	cobol_expert	thanks, for some reason I thought defn provided that
02:33	vu3rdd	slyrus: I am using the released lein version 1.2.0 to create a uberjar of the latest lein
02:34	vu3rdd	slyrus: I created a new uberjar of lein (current git master) and tried it. Still same problem
02:34	vu3rdd	it is something to do with maven-ant-tasks
02:36	vu3rdd	Ok, problem goes away if I change java invokation in lein with -noverify option. Very wierd..
02:41	hiredman	why are you uberjaring lein?
02:56	vu3rdd	hiredman: I am trying to build lein itself.
02:57	vu3rdd	hiredman: The main goal is to create a debian package of lein. But debian has more recent versions of ant etc. So I wanted to create a workspace where I can play with lein itself
03:20	cais2002	hi guys, for logging, is it recommended to use clojure.contrib.logging ?
03:31	Lajla	cais2002, not sure, but I recommend that you Worship His Shadow.
03:31	Lajla	cais2002, also, if I really asked you nicely and gave you a hug, would you eat my eyeball in front of me?
03:38	raek	cais2002: I haven't used c.c.logging myself, so I don't have any good pointers except for searching the google group
03:39	raek	maybe it can get you at least one a little bit on the way
03:39	raek	http://groups.google.com/group/clojure/search?group=clojure&q=logging
03:40	cais2002	raek: thanks, I just used it and it is pretty intuitive to use
07:13	sergey_miryanov	hi clojurians!
07:14	sergey_miryanov	what heard about status of last-var-wins? it's very annoying to restart repl for each file reload :/
07:31	zmyrgel	any idea what is wrong as I get IllegalArgumentException when I try to run default conjure site
08:14	aldebrn	So I can't add a docstring to defmulti's?
08:16	rhudson	? (doc defmulti) says you can
08:18	aldebrn	Aha, sorry for the dumb question. Much appreciated rhudson
10:26	sid3k	hello clojure!
10:37	chouser	hello sid3k!
10:43	Raynes	chouser: PING!
10:43	chouser	Raynes: hello
10:43	Raynes	That is the 4th time I've pinged you in 4 days. :p
10:43	Raynes	chouser: Hold on, give me a second to remember what I wanted to whine about.
10:43	chouser	heh
10:45	Raynes	chouser: Found it. In the latest MEAP, section 8.1.4, first code example.
10:46	Raynes	The example does this: (:use (clojure set xml))
10:46	Raynes	(:use [clojure.test :only (are is)])
10:46	Raynes	Is there a particular reason for that?
10:46	Raynes	It could be (:use (clojure set xml) [clojure.test :only (are is)])
10:50	chouser	Raynes: right, either would be fine. The indentation is perhaps a little cleaner this way.
10:51	chouser	we'll look at it.
10:51	fogus	Raynes: That specific example has an accompanying discussion that walks down the line explaining what each directive does. The separation sort of feel out of the discussion.
10:52	chouser	fwiw, you can report future things on the forum, rather than waiting for fogus or me to show up here
10:52	Raynes	I see. Do you demonstrate the single-use style anywhere else in the book?
10:52	chouser	http://www.manning-sandbox.com/thread.jspa?threadID=38170&tstart=0
10:52	Raynes	If not, it's probably a good idea.
10:52	Raynes	I would, but it didn't really feel like a report and it certainly wasn't important.
10:52	Raynes	It was really just a question about whether there was a specific reason for it.
10:52	Raynes	:)
10:53	cais2002	Raynes: still remember we talked about a replace-key functions the other day? I just realized that there is one pre-defineed function that does that
10:53	cais2002	-> (doc clojure.set/rename-keys)
10:53	cais2002	,(doc clojure.set/rename-keys)
10:53	clojurebot	"([map kmap]); Returns the map with the keys in kmap renamed to the vals in kmap"
10:53	Raynes	cais2002: Oh, good. :)
10:54	Raynes	Hrm.
10:54	cais2002	but the second param kmap has to be a real map
10:54	Raynes	Where oh where did my sexpbot go.
10:54	cemerick	chouser: wasn't there a ticket open for moving clojure.contrib.lazy-xml/emit to clojure.xml?
10:55	fogus	Raynes: We added much more about namespaces that is not included in the latest MEAP update, so yes. Although I do not know when you will see it. :O
10:55	Raynes	Methinks Licenser's server restarted or something.
10:56	chouser	cemerick: I've suggested it, but I'm not sure I've ever heard rhickey voice any support.
10:58	Raynes	Oh, it just dropped on freenode. Odd. I really need to add reconnection support to irclj.
10:59	Raynes	-> (clojure-version)
10:59	sexpbot	=> "1.2.0-beta1"
10:59	cemerick	chouser: I remember there being concerns about more hosty dependencies getting into those "core" namespaces. clojure.java.xml coming soon, perhaps.
10:59	Bahman	Hi all!
11:00	Raynes	Bahman: Hello there!
11:00	Raynes	:)
11:01	Scriptor	hey Bahman
11:01	chouser	cemerick: hm, perhaps. though the api provided by c.c.lazy-xml is fully wrapped, I think, so could be implemented on other hosts without API change.
11:01	Bahman	Hi there Raynes and Scriptor!
11:05	cemerick	fogus: which changes? Last I see are from the 16th?
11:07	fogus	cemerick: saw some ticket updates about clojure.xml/emit earlier today.
11:12	slyrus	i don't suppose I can use recur and a lazy-seq together can I?
11:13	chouser	slyrus: depends on how. :-)
11:16	slyrus	fair enough...
11:17	chouser	'range' for example uses both lazy-seq and loop/recur
11:18	slyrus	I see I can put the lazy-seq in the args of recur. I can't figure out how to get the lazy-seq around the recur call. not sure if that's even a good idea.
11:18	slyrus	the function in question is my breadth-first-traversal routine, or the bft-recur variant anyway: http://github.com/slyrus/shortcut/blob/master/src/shortcut/graph.clj#L163
11:19	chouser	you can't have a recur inside a lazy-seq form that jumps to something outside the lazy-seq form.
11:19	chouser	or that tries, because it won't work. :-)
11:19	slyrus	that's what I thought :)
11:20	slyrus	now I have to decide which is worse, not using recur or not returning a lazy-seq...
11:27	chouser	slyrus: if what you're trying to do makes sense, there's probably a way to arrange the code so you can use both.
11:28	slyrus	yeah, I can put the lazy-seq call in the args to recur. not sure if that makes sense though! I'm going to punt for the moment.
12:13	lozh	Put my first reasonably big chunk of clojure at http://gist.github.com/490689 would welcome any feedback on style/simplfication etc
12:16	cemerick	lozh: the in-ns is superfluous (implied by ns). Put your imports in the ns declaration (e.g. (:import (java.awt Robot ...))).
12:17	lozh	thanks
12:17	cemerick	Without getting into what you're actually doing, those are the only obvious things. :-)
12:22	Raynes	lozh: Also, you can supply a docstring to your ns rather than make all of the above comments.
12:23	lozh	Ah, I was just copying clojure .core, didn't realise that, thanks
12:23	Raynes	You don't have to. It's usually something libraries do. Just an idea. :D
12:24	Raynes	lozh: Here is an example: http://github.com/Raynes/clj-github/blob/master/src/clj_github/gists.clj
12:24	edbond	'lein deps' delete all in lib/ dir?
12:25	lozh	Raynes: I see what you mean, thanks
12:25	edbond	where is the safe place to put org.apache jars?
12:25	Raynes	edbond: In leiningen 1.2, I'm fairly certain Leiningen does an implicit clean beforehand.
12:25	Raynes	edbond: A maven repository.
12:25	Raynes	If you're using Leiningen for dependency management, you shouldn't be using jars that aren't in a maven repository.
12:25	Raynes	It kills the whole point.
12:26	Raynes	apache stuff is in maven central. If you run into some jar that you need, and it's open source, you can upload it to clojars if it isn't already in a maven repo.
12:27	edbond	Raynes: how to search for something in maven central?
12:29	Raynes	http://mvnrepository.com/ is a maven repository search engine.
12:29	Raynes	There are others.
12:30	edbond	Raynes: thanks a lot
13:22	janne	what's the easiest way to map [1 2 3] into [{:foo 1} {:foo 2} {:foo 3}] ?
13:22	KirinDave	Probably (map #({:foo %1}) [1 2 3])
13:23	KirinDave	,(map #({:foo %1}) [1 2 3])
13:23	clojurebot	java.lang.IllegalArgumentException: Wrong number of args (0) passed to: PersistentArrayMap
13:23	janne	yeah, I tried that but it doesn't work
13:23	Nikelandjelo	,(map (fn [a] {:foo a}) [1 2 3])
13:23	clojurebot	({:foo 1} {:foo 2} {:foo 3})
13:23	janne	hmh
13:24	KirinDave	Weird.
13:24	janne	what's wrong with that
13:24	janne	yeah, really weird
13:25	hiredman	,(macroexpand-1 '#({:foo %1}))
13:25	clojurebot	(fn* [p1__499900#] ({:foo p1__499900#}))
13:25	KirinDave	Ah
13:25	KirinDave	There's the problem. :)
13:25	KirinDave	#() isn't equipped.
13:30	Nikelandjelo	,(map #(hash-map :foo %) [1 2 3])
13:30	clojurebot	({:foo 1} {:foo 2} {:foo 3})
13:35	fogus	,(for [i [1 2 3]] {:foo i})
13:35	clojurebot	({:foo 1} {:foo 2} {:foo 3})
13:38	cddr	can leiningen be used to build projects which rely on non-jvm languages?
14:18	technomancy	cddr: well, it's turing-complete, so ...
14:18	technomancy	but I don't think anyone has done much of that so far.
14:50	akhudek	hm, I was going to take advantage of laziness of map, an almost got bit by chunked sequences
14:51	akhudek	it's not clear from the documentation that map will often grab chunks, and if you want true item at a time behaviour you need to pass in something like a list
14:51	LauJensen	akhudek: ouch
14:52	LauJensen	akhudek: And yea, the documentation isnt specific enough
15:30	cemerick	akhudek: that mattered to me recently as well -- (mapcat list some-chunked-seq) will ensure one-at-a-time behaviour, in case you hadn't determined that already.
15:32	akhudek	cemerick: yep, I discovered this. I just wanted to comment that it is important to have this documented at some point so people don't accidentally get tripped up.
15:43	cemerick	akhudek: I agree, though it's a tough documentation issue -- chunking behaviour is entirely automatic, and transparent in the overwhelmingly common use case (lazy seq processing). Anyway, see http://blog.fogus.me/2010/01/22/de-chunkifying-sequences-in-clojure/ for what might come along in 1.3.
15:46	akhudek	that looks promising!
15:46	chouser	it's also possible chunked seqs might just go away
15:46	akhudek	are they causing trouble elswhere?
15:47	chouser	not that I know of, but pods may allow better performance yet for similar pipelines
15:47	akhudek	ah
15:48	chouser	I haven't heard that stated recently, so I maybe mis-remembering or things may have changed again.
16:01	cemerick	I've been under a rock. Pods are cells, right?
16:02	TakeV	Are there any Clojure libraries for hash generation, or do we just use the Java APIs for that?
16:02	cemerick	TakeV: what are you trying to get a hash for?
16:04	TakeV	cemerick: Playing around with password stuff. I know it's pretty bad form to keep the password stored, so I want to do a hash of it to compare.
16:05	cemerick	ah
16:05	chouser	cemerick: I think so, yeah.
16:05	cemerick	TakeV: MessageDigest is pretty straightforward to use.
16:05	TakeV	Is that in contrib?
16:06	cemerick	TakeV: no, it's a JRE library. java.security.MessageDigest
16:06	cemerick	s/library/class
16:07	TakeV	Ah, alright. Thanks. :)
16:09	cemerick	TakeV: Here's my (pre-protocols) hash-of multimethod. It's SHA1-only, just because that's what we use overwhelmingly.
16:09	cemerick	https://gist.github.com/83ce26f6ad06d5bda025
16:10	cemerick	man, that's some old code :-P
16:10	TakeV	SHA1 isn't bad. Could be worse. :P
16:11	cemerick	hrm, the MiscUtilities class is mine too -- replace that with (MessageDigest/getInstance "SHA1")
16:11	TakeV	Sure.
16:12	TakeV	Man, I love github...
16:12	cemerick	TakeV: 'course, that'd be a single fn given io/input-stream. I'm probably not doing you any favors by pasting that.
16:13	TakeV	It's enough to work off of. A nice seed.
16:19	seancron	How can I start a thread that runs, while the rest of the code executes?
16:19	mefesto	(doto (Thread. f) (.start))
16:20	mefesto	where 'f is the function you want to run in that thread
16:20	mefesto	or you can use a thread pool using Executors
16:21	seancron	How would I use a thread pool?
16:21	cemerick	seancron: Read about agents and send/send-off. Starting new threads as mefesto is almost never necessary or desirable.
16:21	cemerick	s/mefesto/mefesto suggests
16:21	mefesto	oops, yeah, agents totally slipped my mind :-\
16:22	seancron	Okay. I'm trying to show a GUI while I make network connections.
16:22	TakeV	Yeah, I was just about to ask if threads are really needed, given the existence of agents.
16:22	cemerick	seancron: take a look at c.c.http.agent
16:23	cemerick	(if you're doing http, that is)
16:23	seancron	I'm actually doing DNS right now
16:24	cemerick	seancron: then agents are the way to go, or maybe futures (though I suspect not)
16:24	arkh	what's wrong with the following?: (apply #(str %) ["one" "two" "three"])
16:24	arkh	I know I'm missing something basic :(
16:24	mefesto	arkh: just (apply str ["one" "two" "three"])
16:24	opqdonut	#(str %) takes only one argument
16:24	opqdonut	and what mefesto said
16:25	arkh	using str in an anonymous function is a placeholder for what I'd really like to do. Am I passing three arguments to #(str %) with the above?
16:27	mefesto	arkh: yeah, apply will call the passed function with the collection as it's arguments
16:27	technomancy	agents are value-oriented. sometimes you need Threads that don't necessarily revolve around a single identity
16:27	arkh	mefesto: , opqdonut: ok - thank you
16:28	TakeV	technomancy: What about, say, separating game logic and drawing in a video game? Would threads be better suited for that than agents?
16:30	duncanm	any of you use the netbeans platform?
16:31	technomancy	TakeV: I think drawing is a good candidate for a background Thread as it's pretty side-effecty. "game logic" is a little too vague to make the call.
16:31	TakeV	technomancy: I see.
16:31	arohner	TakeV: though you have to be careful with drawing in a separate thread. Many GUIs are picky about only doing drawing operations in a specific thread
16:33	lozh	I've not done much game programming, but the game loops I've seen normally manually interleave the update and the drawing, makes the locking easier, and both have to be pretty well time bounded for a smooth gameplay anyway
16:34	ordnungswidrig1	aikido
16:38	arkh	if I have a seqence of strings, what's a good way to print them out, one string per line, with spit?
16:38	mefesto	arkh: doseq ?
16:39	mefesto	(doseq [l lines] (println l))
16:39	arkh	mefesto: oh ... I didn't think to use println. That's java's isn't it?
16:40	arkh	mefesto: sorry and nvm (and thank you). A (doc println) says otherwise
16:40	clojurebot	defmulti doc is ugly
16:50	slyrus_	not sure if this is a bug or a feature. but if I :use clojure.contrib.seq, I can't C-c C-k my clojure file without getting the following error: error: java.lang.IllegalStateException: partition-by already refers to: #'clojure.contrib.seq/partition-by in namespace: foo
16:50	slyrus_	clojure.contrib.graph, on the other hand, for example, is fine. must be something about the :refer-clojure :exclude in seq's ns form
16:51	chouser	partition-by is defined in c.c.seq, but was promoted to clojure.core, so now it's in both places -- hence the error.
16:52	chouser	you shouldn't really be doing :use without naming the specific vars you want anyway.
16:53	slyrus_	hmm... the fact that it compiles fine the first time through and breaks the second time makes me suspicious that this is the intended behavior.
16:54	slyrus_	and do you really mean I should call out every function I plan to use from an ns when I :use an ns? that seems a bit tedious.
16:59	mefesto	slyrus_: you can also 'require :as something so you don't have to name each var you need
17:02	chouser	slyrus_: I highly recommend against naked :use. Either alias the namespace with :as or call out each function with :only
17:02	chouser	of course that's just my opinion, but it would help with situations like this, as well as others.
17:09	Nikelandjelo	chouser: It's inconvenient (for me) when exploring some clojure contrib libs in repl and don't know what I need :( Is there are a way to not load function, which already exist, to escape this error?
17:10	chouser	if it's a clojure.core function, that should only be a warning and you should be able to proceed.
17:11	qbg	Nikelandjelo: There is an :exclude and :rename option for use
17:15	djpowell	hmm - I think clojure.java.shell has got messed up
17:17	Raynes	Heh. You know your language is getting popular when articles starting with single-digit numbers and assertions begin to pop up. http://twoguysarguing.wordpress.com/2010/07/26/7-rules-for-writing-clojure-programs/
17:20	chouser	heh
17:28	slyrus_	chouser: I assume you wouldn't apply the same recommendations to things in the same umm... project, right? do you really explicitly call out things used in foo.core by foo.baz and vice versa? or just do a :use?
17:29	chouser	slyrus_: perhaps I'm a bit pedantic, but if it's not defined in the same file, I use a namespace alias prefix or list every function in the :use :only
17:29	slyrus_	interesting. ok, thanks.
17:30	chouser	that always makes it easy to find the definition of every word in your code, as well as keeping strict control of your own namespace.
17:38	lpetit	woops, there's no 1.2-beta1 tag on git ?
17:44	slyrus_	chouser: ok, I think I can used to that.
17:44	lozh	Does the slime-repl in emacs have something to refer to the previous result?
17:45	qbg	You still have *1
17:46	lozh	thanks
17:49	lozh	Heh *1 is one of those things I just can't search for on google, any idea where it's documented?
17:49	qbg	,(doc *1)
17:49	clojurebot	"; bound in a repl thread to the most recent value printed"
17:50	lozh	Oh, it's a clojure thing - thanks!
17:52	slyrus_	chouser: as long as we're being pedantic, why don't we force namespaces to :use clojure.core?
18:01	somnium	once or twice I would've liked to be able to '(require [clojure.core :as core])
18:01	chouser	that works
18:02	somnium	really?
18:05	somnium	ah, cool. this worked (ns ... (:refer-clojure :only []) (:require [clojure.core :as core]))
18:40	nickik	Can somebody help me with this: http://paste.lisp.org/display/112848
18:40	nickik	why is it not working?
18:40	qbg	You should define the macro before use for one thing
18:41	nickik	evaluatet the macro first in my file
18:41	nickik	or repl
18:41	Raynes	Clojure isn't like Haskell. You can't use a function before it's defined unless you forward declare it with (declare)
18:42	qbg	(hash-map rest) looks wrong
18:43	qbg	(apply hash-map rest) would work
18:43	nickik	yeah
18:43	nickik	i was thinking (into {} rest)
18:43	qbg	You are also assuming something about the order of the seq returned by keys
18:44	qbg	(fn [a b] '(a b)) is probably not what you want
18:44	nickik	you mean in the (func .....)
18:44	qbg	Yes
18:44	nickik	it dont think it matters how they are orderd but i should change it for clarity
18:46	nickik	how else can i make a list of list like this ((key value) (key value))
18:46	qbg	(seq {:a 1 :b 2})
18:46	qbg	,(seq {:a 1 :b 2})
18:46	clojurebot	([:a 1] [:b 2])
18:48	tomoj	qbg: you mean we can't assume that keys and vals are in matching order?
18:48	tomoj	that would be strange
18:49	qbg	,(into {} (for [x (range 26)] [(keyword (str (char (+ (int \a) x)))) x]))
18:49	clojurebot	{:r 17, :z 25, :y 24, :x 23, :a 0, :c 2, :b 1, :f 5, :g 6, :d 3, :e 4, :l 11, :k 10, :j 9, :m 12, :i 8, :n 13, :h 7, :o 14, :v 21, :w 22, :t 19, :u 20, :q 16, :p 15, :s 18}
18:50	nickik	i changed it to a sorted-map
18:50	qbg	,(keys (into {} (for [x (range 26)] [(keyword (str (char (+ (int \a) x)))) x])))
18:50	clojurebot	(:r :z :y :x :a :c :b :f :g :d :e :l :k :j :m :i :n :h :o :v :w :t :u :q :p :s)
18:50	qbg	nickik: Wouldn't an array-map be better here?
18:51	tomoj	,(keys (into {} (for [x (range 26)] [(keyword (str (char (+ (int \a) x)))) x])))
18:51	clojurebot	(:r :z :y :x :a :c :b :f :g :d :e :l :k :j :m :i :n :h :o :v :w :t :u :q :p :s)
18:51	tomoj	oops
18:51	tomoj	,(vals (into {} (for [x (range 26)] [(keyword (str (char (+ (int \a) x)))) x])))
18:51	clojurebot	(17 25 24 23 0 2 1 5 6 3 4 11 10 9 12 8 13 7 14 21 22 19 20 16 15 18)
18:51	tomoj	whew
18:51	qbg	keys and vals will always match
18:52	qbg	The order in which they are returned will not always be the same as the order they went into the map, of course
18:52	qbg	(which is what I was trying to point out)
18:53	nickik	if i do (let [body (sorted-map rest) func (map (fn [a b] '(a b)) (keys body) (vals body))]) should that be right too?
18:54	tomoj	,(let [m {:foo 1 :bar 2}] (map (fn [a b] '(a b)) (keys m) (vals m)))
18:54	clojurebot	((a b) (a b))
18:54	tomoj	,(let [m {:foo 1 :bar 2}] (seq m))
18:54	clojurebot	([:foo 1] [:bar 2])
18:54	tomoj	much shorter, and it actually works, too! :D
18:55	tomoj	if you really want lists, how would you do it, though?
18:55	tomoj	maybe (map (partial apply list) {:foo 1 :bar 2}) ?
18:56	nickik	ah ok do it like this (fn [a b] '(~a ~b))
18:56	tomoj	(map #(apply list %&) m)
18:56	nickik	or (fn [a b] (into '() [a b]))
18:58	brehaut	massive brain failure: whats the inverse to empty?
18:58	qbg	,(hash-map [1 2 3] "a", :foo 2, "3" 6, 8 9, \a 2, '(1 4 3) 6, 'a 'b)
18:58	clojurebot	{\a 2, [1 2 3] "a", :foo 2, 8 9, a b, "3" 6, (1 4 3) 6}
18:58	qbg	brehaut: seq
18:58	brehaut	cheers
18:58	qbg	,(source empty?)
18:58	clojurebot	java.lang.Exception: Unable to resolve symbol: source in this context
18:58	qbg	(empty? x) is (not (seq x))
18:58	tomoj	oh, hmm
18:59	qbg	,(sorted-map [1 2 3] "a", :foo 2, "3" 6, 8 9, \a 2, '(1 4 3) 6, 'a 'b)
18:59	clojurebot	java.lang.ClassCastException: clojure.lang.PersistentVector cannot be cast to clojure.lang.Keyword
18:59	qbg	,(array-map [1 2 3] "a", :foo 2, "3" 6, 8 9, \a 2, '(1 4 3) 6, 'a 'b)
18:59	clojurebot	{[1 2 3] "a", :foo 2, "3" 6, 8 9, \a 2, (1 4 3) 6, a b}
18:59	nickik	@brehaut (complement empty?)
18:59	qbg	,(doc empty?)
18:59	nickik	but seq better
18:59	clojurebot	"([coll]); Returns true if coll has no items - same as (not (seq coll)). Please use the idiom (seq x) rather than (not (empty? x))"
19:00	nickik	if been doing that after someone mentions it in the mailinglist
19:00	tomoj	just (map #(apply list %1) {:foo 1 :bar 2}), not %&
19:04	nickik	@tomoj that is better thx
19:05	tomoj	er, don't even need the 1
19:06	nickik	better is always posible :)
19:10	tomoj	I feel like there should be a cooler way than #(apply list %)
19:11	qbg	,(map (partial apply list) {:foo 1 :bar 2})
19:11	clojurebot	((:foo 1) (:bar 2))
19:11	hiredman	apply list is seq
19:12	hiredman	,(map seq {:foo 1 :bar 2})
19:12	clojurebot	((:foo 1) (:bar 2))
19:12	tomoj	great :)
19:12	hiredman	why are you doing that anyway?
19:12	tomoj	I'm not, nickik is
19:13	tomoj	macro, so maybe a good reason?
19:14	qbg	,(list? `(5 ~2))
19:14	clojurebot	false
19:15	hiredman	,(doc list?)
19:15	clojurebot	"([x]); Returns true if x implements IPersistentList"
19:15	hiredman	,(class `(5 ~2))
19:15	clojurebot	clojure.lang.Cons
19:15	technomancy	list? is the black-sheep predicate.
19:15	hiredman	,(supers clojure.lang.Cons)
19:15	clojurebot	#{java.io.Serializable clojure.lang.Sequential clojure.lang.Seqable java.util.Collection clojure.lang.IObj java.lang.Object java.util.List clojure.lang.ISeq clojure.lang.ASeq clojure.lang.IPersistentCollection clojure.lang.Obj java.lang.Iterable clojure.lang.IMeta}
19:15	hiredman	not a IPersistentList
19:16	KirinDave	Wait.
19:16	KirinDave	Waaiiiitt a minute.
19:16	KirinDave	http://twoguysarguing.wordpress.com/2010/07/26/7-rules-for-writing-clojure-programs/
19:16	KirinDave	Rule 5 6 7
19:16	qbg	I've used sequential? before once I know something is not a vector to see if something is list like
19:16	qbg	There should be a better way...
19:16	hiredman	seq?
19:16	clojurebot	@ splices in a seq and foo# is a symbol, not a seq
19:16	hiredman	,(seq? (list 1 2))
19:16	clojurebot	true
19:17	hiredman	if it prints in parens it's a seq
19:17	technomancy	even the queuefish?
19:17	KirinDave	I can't believe that -> and ->> are going to be demonized now.
19:18	hiredman	the queuefish is ineffable
19:19	tomoj	demonized?
19:19	tomoj	oh, I see, wow
19:20	tomoj	"Don’t be lazy" ?
19:20	hiredman	pretty sure he doesn't mean it
19:20	hiredman	->> and -> are all about transformation
19:20	sexpbot	=> #<core$_GT_ clojure.core$_GT_@11286929>
19:20	KirinDave	I guess that should be, "Don't do a lot of identical subfunctions when you really want a helper function
19:20	tomoj	oh, I see
19:21	KirinDave	hiredman: "Don’t use -> or ->>" is a nasty pullquote tho.
19:21	hiredman	shrug someone's wrong on the internet
19:21	KirinDave	Also, “Transformation is not recursion.”
19:22	tomoj	"Don't use -> or ->>" is right after "Use -> and ->> to make one liners easier to read"
19:22	nickik	the reason is that I build a function in a macro (cons 'fn .....)
19:22	KirinDave	I wonder if it really is 2 guys arguing.
19:22	tomoj	I think if you're calling things rules you should be somewhat careful about how you phrase them..
19:22	nickik	the ........ are the key - value pairs
19:23	nickik	the key are the args
19:23	tomoj	so if two functions your macro would create happen to have the same arglist...?
19:23	nickik	so (fn ([n] (dosomething)) ([a b] (dosomething)))
19:24	tomoj	maybe that is not a concern for some reason for your macro?
19:25	KirinDave	fogus can't be serious about this.
19:25	nickik	its complicated to explain
19:27	nickik	ihas nothing to do with fogus
19:27	nickik	*it
19:28	tomoj	nickik: no one will ever do something like (def-contracted-fn foo :contract bar [a b] baz [a b] bing)? that's what I meant
19:28	tomoj	oh you're just passing them to fn, so it doesn't matter :)
19:29	nickik	why not its better then define contracts outside and then do the (def somename (with-contrains your-function your-contract))
19:30	nickik	and you could use more then one contract for one function if you do :contract [contract-1 contract-2]
19:30	nickik	the name def-contracted-fn is just temp
19:34	tomoj	huh
19:37	nickik	I just dont want to defin a contract then a function and then a nother def to connect them both
19:38	tomoj	were you not responding to what I said?
19:40	slyrus_	como se dice digit-char-p in clojurian?
19:41	slyrus_	,(int \3)
19:41	clojurebot	51
19:42	nickik	@tomoj only saw the second thing just now sry
19:42	tomoj	nickik: no problem, was just confused
19:43	tomoj	slyrus_: what would (int (char 3)) return?
19:43	tomoj	or, if that returns 3, what would (char 51) return?
19:44	slyrus_	^c doesn't represent an integer, throw an error.
19:44	slyrus_	yeah, yeah...
19:44	slyrus_	presumably there's some unicode char <--> char-code mapping going on somewhere, no?
19:46	mefesto	,(map int (map char "123abc"))
19:46	clojurebot	(49 50 51 97 98 99)
19:47	mefesto	err strings are char seqs so...
19:47	mefesto	,(map int "123abc")
19:47	clojurebot	(49 50 51 97 98 99)
19:47	nickik	thanks for the help. My first real macro works ... in some cases :)
19:48	slyrus_	,(int \a)
19:48	clojurebot	97
19:49	slyrus_	who says that (int \a) is 97? the clojure language spec? latin-1? presumably the way characters are converted to ints is documented somewhere.
19:49	mefesto	slyrus_: i think ascii and beyond
19:50	somnium	slyrus_: could you do something like (when (<= 48 (int c) 57) (- (int c) 48))? or (Integer/parseInt (str \3))
19:50	slyrus_	sure, I _could_. I'm used to having a nice handy digit-char-p lying around which I found much more attractive and readable than either of those, thank you...
19:51	somnium	slyrus_: there's always that handy `defn' in a pinch :)
19:51	tomoj	slyrus_: do you care about the radix arg?
19:51	slyrus_	not at the moment
19:51	tomoj	#(.isDigit %) would work, I think
19:52	tomoj	oh, no
19:52	tomoj	#(Character/isDigit %)
19:53	mefesto	slyrus_: fyi, http://en.wikipedia.org/wiki/ASCII#ASCII_printable_characters
19:53	mefesto	slyrus_: i think utf-8 is mostly backward compatible with that table
19:54	somnium	,(Character/digit \3 9)
19:54	clojurebot	3
19:55	somnium	,(Character/digit \a 9)
19:55	clojurebot	-1
19:55	somnium	slyrus_: warmer?
19:57	slyrus_	mefesto: I'm less interested in the ascii printable characters and more interested in knowing how clojure knows about that wikipedia page
19:57	slyrus_	or at least the mapping contained therein
19:57	mefesto	slyrus_: i think it's less clojure and more how java does things
19:57	slyrus_	does it just hand all of the string encoding stuff of to javaland?
19:57	mefesto	jvm using utf-8 i believe
19:57	mefesto	*uses
19:58	somnium	http://java.sun.com/j2se/1.4.2/docs/api/java/lang/Character.html
19:58	slyrus_	thanks somnium
19:58	arohner	slyrus: (int \a) is defined by the ascii spec, as implemented by Java
19:59	slyrus_	ok. I'll use CL for all of my EBCDIC coding requirements then :)
19:59	mefesto	"A String represents a string in the UTF-16 format in which supplementary characters are represented by surrogate pairs (see the section Unicode Character Representations in the Character class for more information)"
20:00	mefesto	http://java.sun.com/javase/6/docs/api/java/lang/String.html
20:01	technomancy	I heard CL is _really_ good at EBCDIC
20:04	slyrus_	ok, thanks for the help everyone. the important point, for me, is that Character/digit will handle the encoding for the code point and do the right thing.
20:05	slyrus_	so Character/digit is the digit-char-p equivalent i was looking for
20:05	slyrus_	which is much nicer than, say, subtracting 48 from (int the-char).
20:13	slyrus_	,(chars "moose")
20:13	clojurebot	java.lang.ClassCastException: java.lang.String cannot be cast to [C
20:16	tomoj	,((juxt identity seq) (.toCharArray "moose"))
20:16	clojurebot	[#<char[] [C@184dc10> (\m \o \o \s \e)]
20:16	mefesto	,(.toCharArray "moose")
20:16	clojurebot	#<char[] [C@1b995c2>
20:17	slyrus_	tomoj, mefesto: thanks, but the error message could be a little nicer :)
20:17	mefesto	slyrus_: must it be a character array? a string is a seq of chars
20:18	slyrus_	no, i was just surprised at that error, that's all
20:18	slyrus_	and, yes, strings being seqs of chars is indeed very nice :)
20:18	tomoj	could be nicer by saying "char array" instead of "[C"?
20:19	slyrus_	ah, that's what that means. thanks!
20:21	arohner	[C is java's .toString on an array
20:22	arohner	pprint'ing it is nicer
20:22	arohner	,(clojure.pprint/pprint (into-array Character/TYPE [\a \b \c]))
20:22	clojurebot	[\a, \b, \c]
20:23	hiredman	[C is the jvm internal type of an array of characters
20:23	hiredman	[B is bytes
20:23	hiredman	etc
20:24	hiredman	[Ljava/lang/Object; is objects
21:23	reburg	why doesn't #({% 1}) work, while (fn [a] {a 1}) does?
21:23	cemerick	#({% 1}) is the equivalent of (fn [a] ({a 1}))
21:24	reburg	cemerick: but (#{% 1} :foo) throws an exception
21:24	reburg	oh wait
21:24	reburg	i see what you typed now
21:24	reburg	cemerick: thank you!
21:25	cemerick	reburg: #(hash-map % 1) is what you want (though that's a little odd :-)
22:12	Drakeson	technomancy: ping