#clojure – 2015-01-26

2015-01-26

00:00	tomjack	one extension point I discovered: (defmethod core.match/emit-pattern-for-syntax [:foo :default] ...)
00:01	tomjack	then (match x (:foo y) :ok)
00:04	tomvolek	HI guys, I am trying to execute some sample syntax in Repl like : (difference #{1 2 } #{2 3}) I get error message "CompilerException java.lang.RuntimeException: Unable to resolve symbol: difference in this context," I thouth difference is in the core which gets loaded by Repl .
00:04	justin_smith	tomjack: clojure.set/difference
00:04	justin_smith	here's how you can find it ##(apropos "difference")
00:04	lazybot	⇒ (difference)
00:05	justin_smith	erg... it behaves better in newer versions, heh
00:05	justin_smith	(actually shows the full ns)
00:05	tomvolek	thanks
00:07	justin_smith	yeah, with 1.7.0-alpha4 I see the whole ns with apropos
00:07	justin_smith	&clojure-version
00:07	lazybot	⇒ {:major 1, :minor 7, :incremental 0, :qualifier "alpha1"}
00:08	justin_smith	,clojure-version
00:08	clojurebot	{:interim true, :major 1, :minor 7, :incremental 0, :qualifier "master"}
00:17	brainacid	I have installed lein, LightTable and jvm and looking through The Joy of Clojure
00:17	brainacid	~book
00:17	clojurebot	book is books
00:17	brainacid	~book
00:17	clojurebot	book is http://www.pragprog.com/titles/shcloj/programming-clojure
00:19	brainacid	~book
00:19	clojurebot	book is http://www.pragprog.com/titles/shcloj/programming-clojure
01:18	jinagarano	i want t build an h2 database to use with korma. i set up a migration file for ragtime that builds the tables "students," "teachers," "guests," "contact-details," "emergency-contacts," and "address." how do i define the relationship between them? eg students should have an address, contact details, and an emergency contact; emergency contacts should have only contact details; and teachers will have an address and contact details, bu
01:19	EvanR	adios
01:19	justin_smith	jinagarano: the end of your question was cut off, because the question was too long
01:19	jinagarano	justin_smith: where did it cut off?
01:19	justin_smith	; and teachers will have an address and contact details, bu
01:20	jinagarano	but no emergency contacts.
01:22	justin_smith	jinagarano: the typical approach is to have a unique ID column on each table, and then and have fields in other tables with content that points to those ids, and use the id field for a join on the tables in your query
01:26	jinagarano	justin_smith: if i understand you right, I create tables in SQL and nothing more; i create table entities in korma to match, and don't use "belongs-to" or "has-many" right? i create all linking in the functions that query my db.
01:27	justin_smith	jinagarano: I believe so, with h2 at least
01:27	justin_smith	maybe korma has something higher level that you want to use though
01:29	justin_smith	jinagarano: for many to many you would actually want a separate table, with an a_id column and a b_id column to create each of the cross table relations
01:29	justin_smith	since having one refering id on each would not suffice, of course
01:30	jinagarano	from korma docs:
01:30	jinagarano	;; Relationships
01:30	jinagarano	(has-one address)
01:30	jinagarano	;; assumes users.id = address.users_id
01:30	jinagarano	(has-many email)
01:30	jinagarano	;; assumes users.id = email.users_id
01:30	jinagarano	;; but gets the results in a second query
01:30	jinagarano	;; for each element (belongs-to account)
01:30	jinagarano	;; assumes users.account_id = account.id
01:30	jinagarano	(many-to-many posts :users_posts))
01:30	jinagarano	;; assumes a table users_posts with columns users_id
01:30	jinagarano	;; and posts_id
01:30	jinagarano	;; like has-many, also gets the results in a second
01:30	jinagarano	;; query for each element
01:30	justin_smith	jinagarano: do not do that
01:30	justin_smith	use a paste site like refheap.com, or provide a link to the source on github
01:30	justin_smith	please
01:31	jinagarano	ok sure, sorry
01:31	jinagarano	i think i know how to do it now, thanks
01:31	justin_smith	jinagarano: yeah, I didn't see you mention korma at first, and I am not as familiar with that, but if you are using korma it looks like those are the functions you would want
01:31	justin_smith	cool
01:32	justin_smith	jinagarano: but do notice that those are query functions - they assume those tables / fields I mentioned above exist already
01:32	justin_smith	but yeah, you should have a clear idea of how to make those columns / tables now
01:49	jinagarano	how do i set up ragtime and h2 for migrating?
01:52	justin_smith	if you are using clojure.java.jdbc, it shouldn't be different from using any other db backend I don't think
01:53	justin_smith	https://github.com/weavejester/ragtime/wiki/Getting-Started just use the apropriate jdbc url
02:03	drorbemet	Hi, do you know how to create a new namespace together with a new file and folders in a single command in emacs in a clojure project?
02:06	justin_smith	drorbemet: specify the full path that reflects the namespace you want to create (even if some subdirectories don't exist), then M-x make-directory and the default option if you hit return is to create all the parent directories for that file
02:07	justin_smith	drorbemet: when I say "specify the full path", do it as a file open, it will create a new file if the file you attempt to open does not exist
02:09	drorbemet	justin_smith: ok, that's the first step, but I didn't find a "create new namespace" command, I just want to make shure that I don't miss somthing before I write an elisp function or a yasnippet
02:12	justin_smith	drorbemet: there is a function to insert an ns declaration
02:12	justin_smith	and that is automatic based on the file name
02:13	drorbemet	justin_smith: oh, there is?! great
02:22	drorbemet	justin_smith: cljr-refactor contains an example, cljr-move-form is what I was looking for, thanks
03:06	zacts	hum.. I'm looking for a book that teaches functional programming really well, and in a down to earth way, that I could apply directly to clojure
03:07	SagiCZ1	zacts: little schemer perhaps?
03:07	zacts	hum.. yeah I own that book, but I'm thinking something more textbook style, yet still down to earth
03:07	SagiCZ1	down to earth as in easy to understand?
03:07	zacts	yeah
03:07	zacts	perhaps not quite so academic as SICP
03:07	SagiCZ1	i liked this one http://shop.oreilly.com/product/0636920013754.do
03:07	codestorm777	functional thinking, maybe
03:07	zacts	I hope to get through SICP, but that might take months to digest
03:08	zacts	codestorm777: is that a book?
03:08	zacts	SagiCZ1: oh cool, yeah I plan to read that too
03:08	codestorm777	yes, o’reilyy, it’s also a video series
03:08	zacts	oh neat. I'll check it out
03:09	SagiCZ1	the oreily book has some thoughts about how to make your programs more abstract shown on examples
03:10	zacts	oh cool
03:13	zacts	hm.. I can't wait until the grokking functional programming by manning press is out
03:13	zacts	that's kind of what I'm looking for
03:13	zacts	exactly too
03:13	clojurebot	I don't understand.
03:16	ro_st	any logback pros in the room? i need to log a specific set of namespaces to a different output file without it going to the file that the rest of the namespaces go to
03:43	acron^	morning
03:43	acron^	new clojurist here; if anyone's got the time, i'd appreciate some feedback on style and form - https://github.com/acron0/fae-scraper/blob/master/src/fae_scraper/core.clj
03:43	slipset	depends on your timezone, I guess
03:44	SagiCZ1	acron^: i also have morning.. good morning
03:44	acron^	:)
03:44	acron^	good [morning\|afternoon\|evening] then...just in case
03:44	SagiCZ1	acron^: maybe move to comments into the fn? you know if you add string after the arg list it is a regular doc
03:45	SagiCZ1	(doc take)
03:45	clojurebot	"([n] [n coll]); Returns a lazy sequence of the first n items in coll, or all items if there are fewer than n. Returns a stateful transducer when no collection is provided."
03:45	SagiCZ1	like this
03:45	acron^	ahh
03:45	acron^	(defn foo [x]
03:45	acron^	"comments here"
03:45	slipset	lines 19 and 26, pull out in functions?
03:46	SagiCZ1	,(defn foo [x] "comments" x)
03:46	clojurebot	#'sandbox/foo
03:46	acron^	got it
03:46	SagiCZ1	also consider putting the arg list on a new line if it is longer.. depends on your taste though
03:46	acron^	slipset: you mean separate it more?
03:47	slipset	also, I'm not to enthused about prefixing functions as in "fae", but YMMV
03:47	acron^	is there a convention?
03:47	slipset	acron^:yes especially the anon-function in line 26. Imagine you wanted to test that...
03:47	acron^	i guess all the funcs are namespaced so no need for a prefix >
03:48	Glenjamin	isn't it docstring before arglist? i always get mixed up :s
03:48	slipset	acron^: I kind of like writing functions so that I can do the following:
03:48	SagiCZ1	Glenjamin: docs after arglist
03:48	Glenjamin	,(doc foo)
03:48	clojurebot	"([x]); "
03:48	acron^	whats the 'feel' on anon functions? good? bad?
03:48	SagiCZ1	slipset: i wouldnt extract that.. if it is the only place where he uses it.. he could test the whole function
03:48	slipset	,(map (partial + 1) [1 2 3])
03:48	clojurebot	(2 3 4)
03:48	SagiCZ1	acron^: they are perfectly idiomatic
03:48	Glenjamin	,(defn foo "comments" [x] x)
03:48	clojurebot	#'sandbox/foo
03:48	Glenjamin	,(doc foo)
03:48	clojurebot	"([x]); comments"
03:48	Glenjamin	it's docstring before arglist.
03:49	acron^	:o
03:49	SagiCZ1	Glenjamin: indeed.. my bad
03:49	acron^	,(defn bar [x] "test" x)
03:49	slipset	SagiCZ1:I would, since then I could give the funciton a name, which kind-of documented what it did.
03:49	clojurebot	#'sandbox/bar
03:49	acron^	,(doc bar)
03:49	clojurebot	"([x]); "
03:50	SagiCZ1	slipset: i absolutely hate extracting something just to give it a name.. it fractures the code.. but i understand it is a matter of opinon..
03:50	slipset	That way I didn't have to try to figure out what (assoc
03:50	slipset	(:attrs %)
03:50	slipset	:desc (:alt (:attrs (first (:content %))))) was trying to achieve
03:50	SagiCZ1	slipset: in this case it would help i guess
03:51	slipset	:)
03:51	acron^	on line 43, I have a dissoc and and assoc
03:51	acron^	is there a better way to reformat a dict?
03:51	SagiCZ1	acron^: yeah i dont like that line very much.. try to keep the line shorter
03:51	slipset	acron^: in line 43 you deffo want a ~doseq
03:52	slipset	~do-seq
03:52	clojurebot	It's greek to me.
03:52	hellofunk	if you have trouble remembering if comments come before or after arglists, just remember how multi-arity fns are structured. it's one comment for the function, regardless of the number of arity implementations.
03:52	SagiCZ1	~doseq
03:52	slipset	~doseq
03:52	clojurebot	doseq is like for, but for side effects instead of values
03:52	clojurebot	doseq is like for, but for side effects instead of values
03:52	slipset	Thanks SagiCZ1,
03:52	acron^	hmm]
03:52	SagiCZ1	hellofunk: yeah actually i would prefer if i could comment each arity separately..
03:52	slipset	anyways, the println in 43 will not print the whole thing since map is lazy
03:53	SagiCZ1	slipset: print forces the evaluation
03:53	acron^	not sure I understand do-seq but I'll have a play
03:53	hellofunk	SagiCZ1: no, because the idea is that the function as a whole is a single function -- which it is, so it should have a single unified purpose. therefore, one comment for the function.
03:53	SagiCZ1	,(println (map inc (range 99)))
03:53	clojurebot	(1 2 3 4 5 ...)\n
03:54	SagiCZ1	hellofunk: yeah but then i have to specify all the arities in the one docstring
03:54	hellofunk	acron^: doseq is just like for. the only difference is that for generates a lazy seq while doseq makes side effects like printing, etc. if you understand for, you understand doseq. study for first.
03:54	hellofunk	SagiCZ1: of course but then when an editor gives docstring hints, it doesn't have to know in advance which version of the fn you will use to tell you how the fn works.
03:55	slipset	and SagiCZ1 is of course totally correct wrt println, my bad
03:55	SagiCZ1	hellofunk: makes sense.. okay
03:56	hellofunk	also key thing to note is that doseq always returns nil. so right there you know it's not designed for generating a sequence but rather doing something off in the world instead.
03:56	acron^	ahhh
03:56	acron^	i get it
03:57	acron^	:)
03:57	slipset	in fae-get-image-from-image-page
03:57	slipset	could you just continue your threading?
03:57	clojurebot	Excuse me?
03:57	SagiCZ1	acron^: your map achieves the same thing as doseq but doseq clearly states your intention to not collect the result into a collection
04:01	jinagarano	i'm trying to build an h2 db and use it via korma. when i compile, i get an error "unable to resolve symbol defentity." why? i added korma as a dependency in project.clj and put (use 'korma.db) in the source file.
04:04	acron^	slipset: can you expand on that?
04:06	slipset	(s/id "content-image"))
04:06	slipset	page)
04:06	slipset	(first)
04:06	slipset	:attrs
04:06	slipset	:data-src)
04:08	slipset	also, in line 15, you could use def and comp, I guess, instead of defining your own function.
04:09	TEttinger	slipset: defn has the advantage of being able to add a docstring
04:09	TEttinger	not sure if you can do that with comp
04:10	slipset	(def fae-get-list-page (comp get-page-as-hickory format))
04:11	slipset	or is it the other way around, I can never remember
04:12	slipset	~def
04:12	clojurebot	excusez-moi
04:13	TEttinger	,(doc def)
04:13	clojurebot	Titim gan éirí ort.
04:13	slipset	,(def ted-nugent "The nuge rocks" 123)
04:13	clojurebot	#'sandbox/ted-nugent
04:13	TEttinger	(doc def)
04:13	clojurebot	Cool story bro.
04:13	TEttinger	ha
04:13	TEttinger	,ted-nugent
04:13	clojurebot	123
04:13	TEttinger	,(doc ted-nugent)
04:13	clojurebot	"; The nuge rocks"
04:13	TEttinger	nice
04:14	acron^	,(doc comp)
04:14	clojurebot	"([] [f] [f g] [f g & fs]); Takes a set of functions and returns a fn that is the composition of those fns. The returned fn takes a variable number of args, applies the rightmost of fns to the args, the next fn (right-to-left) to the result, etc."
04:14	acron^	aha
04:15	slipset	I guess the threading macros and comp are somewhat related in terms of functionality
04:15	acron^	just to be totally clear
04:15	acron^	-> is a threading macro ?
04:15	zilti	slipset: But threading macros work left-to-right
04:15	SagiCZ1	acron^: yes
04:15	slipset	but since the threading macros, are well, macros, you can't pass them around
04:16	slipset	like you can with functions
04:16	zilti	slipset: you could pass around #(-> % whatever fns (you use))
04:16	acron^	so whats the impact of using a thread procedurally like in fae-get-image-from-image-page, line 33?
04:16	TEttinger	,(apply str (map (comp char (partial + 64)) [3 1 20]))
04:16	clojurebot	"CAT"
04:17	acron^	it's explicitly lazy?
04:18	TEttinger	that fae- stuff seems really C-style to me... the JVM always has namespaces/packages, you aren't going to have name collisions unless you :use or :require with :refer :all
04:18	slipset	acron^: I'm on a bit of deep water here, but line 33 gets rewritten at compile time.
04:18	acron^	TEttinger: unsurprising, I'm a C programmer, new to Clojure :)
04:18	TEttinger	heh
04:18	slipset	,(-> 1 (+ 3))
04:18	clojurebot	4
04:19	slipset	gets rewritten by the macro expander to
04:19	slipset	,(+ 1 3)
04:19	clojurebot	4
04:19	acron^	slipset: this code is adapted from hickory examples so I guess I dont see the benefit of the thread here
04:19	zilti	,(macroexpand-1 '(-> 1 (+ 3)))
04:19	slipset	at compile-time, not at run time
04:19	clojurebot	(+ 1 3)
04:19	SagiCZ1	acron^: by "threading" we dont mean actual OS thread.. its just an expression that says that the following s-expression get rewriten into the familiar nested structure (..(..(..(..))) .. there is no overhead or speeed impact
04:19	TEttinger	,(-> 1 (/ 3))
04:19	clojurebot	1/3
04:19	TEttinger	,(->> 1 (/ 3))
04:19	clojurebot	3
04:20	acron^	SagiCZ1: ah, that's an important detail
04:20	TEttinger	good to know about ->> , which puts the threaded arg in the last position
04:20	zilti	slipset: It's important to note though that macros are available at runtime
04:20	slipset	there is also some-> which is quite nice
04:20	SagiCZ1	acron^: threading as in putting a thread through the needle.. i guess you are not native speaker?
04:20	TEttinger	SagiCZ1, it tripped me up too the first time I heard of a threading macro
04:21	acron^	SagiCZ1: not native clojure speaker :) i just assume threading/threads means OS threads/coroutines
04:21	acron^	assumed*
04:21	SagiCZ1	yeah okay i guess it's strange even for native speakers.. but yeah it took me some time to understand what it meant
04:22	acron^	,(-> 10 (- 5))
04:22	clojurebot	5
04:22	acron^	,(->># 10 (- 5))
04:22	clojurebot	#<CompilerException java.lang.RuntimeException: Unable to resolve symbol: ->># in this context, compiling:(NO_SOURCE_PATH:0:0)>
04:22	acron^	,(->> 10 (- 5))
04:22	clojurebot	-5
04:22	zilti	,(macroexpand-1 '(->> 10 (- 5)))
04:22	clojurebot	(- 5 10)
04:23	acron^	,(macroexpand-1 '(-> 10 (- 5)))
04:23	clojurebot	(- 10 5)
04:23	acron^	magic
04:23	SagiCZ1	acron^: also check out 'doto' which is commonly used with java interop
04:23	zilti	,(source ->) ; I wonder if that works
04:23	clojurebot	Source not found\n
04:23	SagiCZ1	(source ->)
04:24	acron^	guys, you've been really helpful thanks
04:25	slipset	https://github.com/clojure/clojure/blob/clojure-1.6.0/src/clj/clojure/core.clj#L1558
04:25	alexyakushev	Like Heisenberg said to Hank when he used too many parentheses: "Thread lastly"
04:25	alexyakushev	Or was it "Tread lightly"? We'll never know
04:27	slipset	acron^: Jay Fields writes nicely on the usage of comp and partial, worth a read http://blog.jayfields.com/2011/01/clojure-partial-and-comp.html
04:28	acron^	thanks slipset, I shall
04:29	SagiCZ1	i always think whether i should use partial.. when the #( .. ) construct takes much less space..
04:29	SagiCZ1	partial is also sensitive to the arg order..
04:29	Glenjamin	partial doesn't generate a class, if that's important to you
04:29	SagiCZ1	#() does?
04:30	slipset	SagiCZ1: http://blog.jayfields.com/2011/01/clojure-partial-and-comp.html
04:30	slipset	crap, wrong link
04:30	slipset	SagiCZ1: http://blog.jayfields.com/2013/05/emacs-lisp-font-lock-for-clojures.html
04:30	SagiCZ1	beware of your clipboard!
04:31	slipset	l guess I was lucky this time.
04:31	slipset	SagiCZ1: re arg order, I tend to like to build my functions such that they fit with partial
04:31	SagiCZ1	slipset: oh yeah.. or using an actual lambda symbol for 'fn' .. i saw that in the core.async talk... anyway i will have to ask cfleming if something like that is possible in cursive
04:32	SagiCZ1	slipset: yeah.. 3rd party fn dont always work well though..
04:32	slipset	having said that, I really wish there was a (reverse-args f) function in clojure
04:34	Glenjamin	(defn reverse-args [f] (fn [&args] (apply f (reverse args))))
04:35	slipset	Glenjamin: cool! stuff is so simple in Clojure
04:36	SagiCZ1	slipset: ugh.. not always sadly.. i always struggle rewriting loops into higher order functions like reduce, iterate etc.. i dont always end up with better code
04:38	slipset	SagiCZ1: I don't think I've hardly written a loop in Clojure, apart from in a, well, go-loop
04:38	SagiCZ1	slipset: wow.. well you need to teach me your ways
04:38	acron^	i doubt anyone here can claim to be the perfect programmer SagiCZ1 :)
04:38	slipset	SagiCZ1: :)
04:39	SagiCZ1	slipset: loops like this give me trouble https://www.refheap.com/96481
04:40	clgv	SagiCZ1: seems to be more of an `iterate` - but there is no eager version of `iterate`
04:41	clgv	ah well recursion itself ;)
04:41	Glenjamin	could write as (reduce) using (reduced), but (loop) seems fine for that
04:41	SagiCZ1	Glenjamin: well.. thats the thing.. is the loop fine or should i always try to get rid of it?
04:41	Glenjamin	is it causing you a problem at the moment?
04:42	SagiCZ1	nope
04:42	Glenjamin	then i'd say it's fine
04:42	SagiCZ1	i just dont want to anger clojure gods
04:42	clgv	SagiCZ1: if you have that patternmore often you can write a fitting higher order function
04:43	SagiCZ1	clgv: function or a macro?
04:43	clgv	SagiCZ1: depends on the details, probably function
04:44	slipset	SagiCZ1: you got me, I'm not even clever enough to see what this is doing.
04:44	SagiCZ1	slipset: it just executes steps updates w and b.. and when e (error) is zero it exits
04:48	slipset	SagiCZ1: would something like (take-while p (partition 3 (repeatedly (partial rand-int 3))))
04:49	slipset	be something you could imagine?
04:49	slipset	where p is your step and if-test combined?
04:50	SagiCZ1	possibly
04:50	SagiCZ1	thanks for the idea
04:52	clgv	SagiCZ1: though you will sacrifice speed by rewriting the loop with lazyseq
04:52	SagiCZ1	so there is not much to gain apart from maybe having nicer,, shorter code
04:53	clgv	yeah, but then try `iterate` with a surround `take-while`
04:53	clgv	*surrounding
04:54	SagiCZ1	clgv: i used that construct elsewhere in my project to replace similar loop... i am using atoms to track progress of the loops.. and in the iterate case it was kinda hard to do
04:55	clgv	SagiCZ1: I just recommeded it since it matches the semantics of your snippet pretty closely
04:55	SagiCZ1	clgv: yep.. true
05:32	zarkone	hello all. When i use REPL with clojurescript, cider-jump-to-var doesn't work. Am I do something wrong or it's not possible for now?
05:42	jinagarano	i'm trying to build an h2 db and use it via korma. when i compile, i get an error "unable to resolve symbol defentity." why? i added korma as a dependency in project.clj and put (use 'korma.db) in the source file.
05:44	zacts	where can I get a list of supported clojure platforms? Well, perhaps that's a naive question, is it supported fully by all plaforms that support the jvm fully?
05:45	jinagarano	zacts: yes, that's the point.
05:45	samiswellcool	jinagarano: defentity is in korma.core
05:45	zacts	jinagarano: ah cool
05:46	jinagarano	samiswellcool: stupid question maybe; where do i put korma.core in my project? i'm new to all this, it's probably obvious.
05:46	samiswellcool	just another use statement (use 'korma.core)
05:46	samiswellcool	or in your namespace (ns whatever.whatever (:use korma.core))
05:47	jinagarano	samiswellcool: brillitant, thanks. does a dependency get the files from github/wherever, and make them available in my project?
05:49	samiswellcool	it gets them from clojars I think, but basically yes
05:49	samiswellcool	then you have to include them as needed in individual files
05:51	TEttinger	zacts: I think clojure is compatible with anything that supports Java 6 or higher. Might be as low as 5.
05:51	zacts	TEttinger: cool
05:51	zacts	I'm just curious how well it runs on FreeBSD / OpenBSD
05:51	zacts	I'm considering switching OS on one of my laptops
05:52	TEttinger	almost certain it will run there, not sure if you have access to an Oracle JDK on there
05:52	jinagarano	to expand on the fundamentals - where can i find the h2 db file? i built it with a ragtime migration, and i think i have to link it with korma via (def h2-db (h2 {db :/....})) - right? well, i can't find the file i created.
05:52	zacts	TEttinger: I usually use OpenJDK
05:52	zacts	is that fine for clojure?
05:52	TEttinger	yep!
05:52	zacts	ok neat! :-)
05:54	TEttinger	I wrote a lein plugin to package clojure apps with a standalone JVM, no installation required, using the Packr library. It downloads a pre-made OpenJDK 7 distribution for mac, windows, and/or linux, and assembles an uberjar into one exe with the JVM in a directory next to it
05:54	TEttinger	it's a total hack but does work fine with OpenJDK
06:08	clgv	TEttinger: zacts: it is Java 6 for Clojure 1.6
06:08	zacts	oh cool
06:08	clgv	the versions before 1.6 required only Java 5
06:17	Glenjamin	TEttinger: sounds similar to capsule
06:17	TEttinger	probably!
06:17	TEttinger	Packr is meant for games, primarily
06:17	Glenjamin	oh, not quite
06:17	Glenjamin	https://github.com/puniverse/capsule "Have your JAR automatically choose an appropriate JVM version, set JVM flags, and add an embedded JAR to the boot class path."
06:18	TEttinger	"Java 9 is expected to have a mechanism for packaging stripped-down versions of the JVM."
06:19	TEttinger	interesting
07:17	SagiCZ1	does anyone know how future-cancel works? it cancels toy examples easily but in the real case the thread keeps going even though future-cancel returned true
07:17	Glenjamin	$source future-cancel
07:17	lazybot	future-cancel is http://is.gd/Z4YWxl
07:18	Glenjamin	welp, that wasn't very helpful
07:19	SagiCZ1	i was thinking that it probably needs Thread.yield() somewhere to be able to cancel itself..
07:19	clgv	SagiCZ1: you cant really use it to reliably stop something that is already processed by a thread. but queue futures should be canceled correctly
07:20	SagiCZ1	what is a reliable way to stop the thread then? i see it in every single application.. long running tasks can be cancelled with the cancel button
07:20	clgv	SagiCZ1: you need some predicate (keep-running? ...) in your processing loop
07:20	SagiCZ1	clgv: no other way? thats just awful.. why cant jvm just kill the thread
07:21	clgv	SagiCZ1: just google that, there are a lot of discussions ;)
07:22	clgv	SagiCZ1: the magic of clojure could ease the pain. you write a `stopable` macro that does the check almost transparently.
07:22	SagiCZ1	clgv: yeah.. or maybe use the deprecated stop() method
07:23	clgv	SagiCZ1: and achieve nothing?
07:23	SagiCZ1	clgv: and see this is where i run into problems.. some of my tasks are loops.. ok they could be dealt with.. but some of them are long running HOF like iterated, reduce etc.. i would have to add the checking mechanism to so many places..
07:24	cfleming	SagiCZ1: You want your code to catch InterruptedException, generally
07:25	cfleming	SagiCZ1: Then whatever is doing the stopping can interrupt your thread and you can handle it gracefully.
07:25	SagiCZ1	cfleming: would it raise the exception? i though i would need to check isInterrupted() ..
07:25	SagiCZ1	my future code is already wrapped in try catch and doesnt throw any exception when i call future cancel
07:25	cfleming	SagiCZ1: The Java concurrency primitives check it at various points so you generally don't have to. If the primitives Clojure uses under the hood don't then you'll have to do that yourself, yeah.
07:26	SagiCZ1	cfleming: yeah i am not using any concurrency primitives
07:26	cfleming	SagiCZ1: Sure, but Clojure is on your behalf.
07:26	SagiCZ1	well thats just such a bummer.. i thought clojure would have some better mechanism to deal with this madness
07:26	clgv	http://docs.oracle.com/javase/7/docs/api/java/lang/Thread.html#interrupt%28%29
07:27	clgv	cfleming: seems that exception is just thrown in pretty specific cases
07:27	SagiCZ1	so we have all these futures and promises and delivers and it just all falls back on the primitive java threads which cant be even reliable stopped..
07:28	cfleming	clgv: Yeah, but those cases are actually pretty common. If your code is in a tight loop you'll have to check it yourself, but often you'll finish a bit of work, check a queue or something for more work and get the exception.
07:29	clgv	cfleming: the tight loop scenario seems to be the use case of SagiCZ1
07:29	cfleming	SagiCZ1: You can't stop a thread reliably, right. But the concurrency primitive do provide good (if non-obvious and tricky) ways to do it.
07:30	SagiCZ1	so yeah.. my previous solution was to have an atom called progress.. which was repeatedly checked and when someone from the outside set the value to negative, the thread would immediately stop and return.. i thought future cancel would help me avoid writing the atom checks.. btu i guess i have to go back
07:31	cfleming	SagiCZ1: http://stackoverflow.com/questions/13623445/future-cancel-method-is-not-working
07:31	cfleming	SagiCZ1: And http://docs.oracle.com/javase/tutorial/essential/concurrency/interrupt.html
07:31	SagiCZ1	cfleming: so if i added Thread/yield everywhere it should throw the exception?
07:32	SagiCZ1	yield is basically 0ms sleep
07:33	SagiCZ1	nope.. doesnt throw exception
07:33	cfleming	SagiCZ1: I would check the thread interrupted flag
07:33	SagiCZ1	and then throw the exception?
07:33	cfleming	Or exit your loop, or whatever you need to do, yeah
07:33	clgv	SagiCZ1: from the javadoc of yield "It is rarely appropriate to use this method."
07:34	SagiCZ1	well that javadoc can bite me!
07:34	SagiCZ1	:D
07:34	clgv	SagiCZ1: the remaining description suggest that it is not what you want anyway
07:34	SagiCZ1	(Thread/sleep 0) works.. if i call future-cancel it throws sleep interrupted exception which i can handle
07:35	SagiCZ1	so just add the sleep to every task and it should work
07:35	cfleming	SagiCZ1: yield (IIRC) was to allow your thread to try to give up its runnable status and allow it to be rescheduled. It's an obsolete method to try to influence thread priorities
07:35	cfleming	SagiCZ1: Seriously, just check the interrupted flag and throw the exception
07:35	cfleming	That's what it's for
07:36	SagiCZ1	okay.. i can wrap that into a function so thats ok
07:36	cfleming	Using Thread/sleep will have other effects that you may not want, like affecting the scheduler
07:36	SagiCZ1	thank you very much guys..
07:37	cfleming	SagiCZ1: If you can get a copy, Java Concurrency In Practice is the bible for this stuff, it's a really great book.
07:37	SagiCZ1	cfleming: I am learning clojure so I could avoid Java convoluted concurrency mechanisms..
07:37	cfleming	SagiCZ1: The first five chapters (IIRC) give a great background.
07:37	SagiCZ1	but i guess i will have to learn it one day
07:37	cfleming	SagiCZ1: Yeah, but sometimes you just have to know what's going on
07:39	clgv	SagiCZ1: You have to embrace the host platform my young padawan. ;)
07:40	SagiCZ1	clgv: hehe :)
07:40	SagiCZ1	cfleming: on a completely unrelated note.. do you think Cursive would be able to replace some common core function names with greek symbols? some people use this in emacs.. for example they use lambda symbol for 'fn' etc.. just visually, not internally
07:43	cfleming	SagiCZ1: Yeah, it should be possible to use code folding for that
07:43	SagiCZ1	what is that?
07:44	cfleming	SagiCZ1: To be honest though, it's going to be a very low priority since I've never really seen the point
07:44	SagiCZ1	cfleming: yeah i thought so
07:45	cfleming	SagiCZ1: That when IntelliJ allows you to fold code, like top-level forms. Their engine is actually pretty powerful, so it gets used for a lot of other things, e.g. in Java they hide new HashMap<SomeBigLongThing>() as new HashMap<~>()
07:46	SagiCZ1	oh i know what that is.. ok
07:46	cfleming	SagiCZ1: It basically does what you're asking about. I'm going to use it in the REPL to fold stacktraces, so it'll automatically fold non-Clojure items, or items that aren't in your project, or something similar
07:46	cfleming	SagiCZ1: so they'll be hidden, but you can click or hover to see them
07:47	SagiCZ1	cfleming: yeah thats a great idea with the task traces..
07:51	cfleming	SagiCZ1: So, to answer your original question - it's possible but it's unlikely to happen unless a lot of people suddenly ask for it.
07:51	SagiCZ1	cfleming: understandable
07:52	clgv	cfleming: does cursive provide a plugin api? then he could implement it himself...
07:52	SagiCZ1	cursive is meant to be stand-alone.. so maybe then
07:53	cfleming	clgv: Not yet - it'll provide an extension API, but I'm not sure this would be something you'd be able to achieve with it, at least initially. Someone could always do it as an IntelliJ plugin.
07:58	slipset	SagiCZ1: You've probably considered it, but how 'bout using core.async to solve your problem
07:58	slipset	There is this example floating around, I think in a tbaldridge talk using alts! to choose from diffent channels, one of them being a timeout channel
07:59	SagiCZ1	slipset: yeah it would probably solve it... i started this project before i knew about core.async and this is just a finishing touch so i dont want to rewrite it all.. i actually solved the problem quite gracefully with what guys suggested here
07:59	slipset	cool!
08:00	jinagarano	if i make an h2 db with ragtime migration, where is the resulting file? i want to build a korma layer on top of it and can't figure out how to link them.
08:22	Empperi	HOLY SHIT http://www.itworld.com/article/2875112/ibm-is-about-to-get-hit-with-a-massive-reorg-and-layoffs.html
08:23	Empperi	IBM fires 111 800 people by the end of February
08:23	Empperi	and no, that number is not a typo
08:24	hyPiRion	"IBM fires 1/3 of Iceland"
08:25	Empperi	those numbers are just staggering
08:25	Empperi	several cities are going to shake with their economies after this
08:25	hyPiRion	Is IBM mainly located in the US?
08:26	Glenjamin	i'm aware of lots of UK offices
08:26	Empperi	it's very much global company
08:26	xemdetia	hyPiRion, hardly.
08:26	Empperi	there are several offices in Finland too
08:27	hyPiRion	Then it's probably not as bad of a hit for the cities
08:27	Empperi	really?
08:28	Empperi	when Lehman Brothers bancrupted 26k people lost their jobs
08:28	Empperi	that with the debt fiasco led to current economic situation
08:28	Empperi	no four times more people gets fired at once
08:28	Empperi	that's going to have some serious impact into economy world wide unless those people find new jobs and fast
08:29	hyPiRion	Well, I'm hanging out in #clojure, not #economics. Go figure :p
08:29	Glenjamin	there's no shortage of programming jobs, just because IBM is failing doesn't mean people won't be snapped up by other companies
08:29	SagiCZ1	Empperi: IBM is all over the world
08:29	Empperi	SagiCZ1: that's what I said?
08:29	SagiCZ1	Empperi: so the impacted is spreaded out
08:30	SagiCZ1	milions of people lose their jobs every year
08:30	Empperi	yes but not at once and on one industry at the same time
08:30	SagiCZ1	i doubt couple thousand people losing their jobs caused global economic crisis
08:30	xemdetia	Empperi, IBM is not a stranger to deep cuts like that.
08:30	Empperi	yes, they hold the previoius record
08:31	daniel___	its the apocalypse
08:31	Empperi	if there's some people here working for IBM I feel for you guys
08:32	zacts	ok, back to clojure now
08:32	Empperi	Glenjamin: IBM does a lot of other stuff too than just programming. Actually most of the layoffs are directed to people not doing programming
08:32	Glenjamin	ah :(
08:32	Empperi	old mainframe guys, storage unit etc
08:33	Empperi	business-wise a good move
08:33	SagiCZ1	IBM's services are expensive and useless nowadays.. this was to be expected
08:33	Empperi	but the impact will be felt, badly
08:33	Empperi	SagiCZ1: yeah
08:33	SagiCZ1	Empperi: doubt it.. maybe locally in the specific areas
08:33	Empperi	their attempts to become a cloud provider have been abysmal
08:34	Empperi	but yeah, back to clojure now.
08:34	Empperi	that was just such a huge news I wanted to share it here
08:44	Empperi	oh, btw to the IBM news: "Most of the layoffs will happen in the US, but some international operations will be affected as well"
08:44	Empperi	http://www.cultofmac.com/310012/ibm-prepares-largest-corporate-layoff/#uqtJmQqlX00Ar9kG.99
08:44	hyPiRion	alright, that might be pretty bad
08:45	Empperi	most likely the worst hit is centered around few US cities
08:46	yguan	trying to be familiar with core.async. why should the following fail?
08:46	cfleming	https://news.ycombinator.com/item?id=8944999 "Cringely has made dooms day predictions in the past that were widely innacurate"
08:46	yguan	(let [c (chan)]
08:46	yguan	(go
08:46	yguan	(print (<! c)))
08:46	yguan	(go
08:46	yguan	(let [f (fn [v]
08:46	yguan	(>! c v))]
08:46	yguan	(f "ab")))
08:46	yguan	(Thread/sleep 100)
08:46	yguan	(close! c))
08:46	dnolen	yguan: use a pasting service please :)
08:47	SagiCZ1	yguan: replace thread/sleep with (<! (timeout 100))
08:47	tbaldridge	no, the issue is that you can't use >! and <! outside of a go
08:47	yguan	dnolen, ehh i'll figure out pasting :)
08:47	tbaldridge	and go blocks stop translating at any call to (fn [...] ....)
08:47	SagiCZ1	tbaldridge: he doesnt have them outside of go
08:47	SagiCZ1	oh
08:47	SagiCZ1	nvm\
08:48	yguan	tbaldridge, I see, feel a bit black magic here...
08:48	tbaldridge	there'
08:49	tbaldridge	go blocks are basically nothing but black magic, elven herbs, and dwarven runes
08:50	gfredericks	stop blocks on the other hand just call System/exit, plain and simple
08:50	hyPiRion	those dwarven FSMs
08:51	tbaldridge	yguan: any async translation compiler like core.async, or C#'s async/await is going to have a few caveats, it's just the way the tech has to work if you don't want to transform your entire program
08:51	dnolen	yguan: supporting only shallow yield is a pretty common thing actually
09:08	thheller	dnolen: whats the policy for upgrading closure compiler + library for CLJS? It's been about 6 months
09:09	dnolen	thheller: just someone testing it to make sure it doesn't break everything, it's happened before
09:09	dnolen	thheller: more recent versions of Closure busted browser REPL, not sure if this has been addressed in a release
09:10	thheller	ok thx, will see if I can do some tests
09:13	stuartsierra	thheller: G.Closure compiler releases are on search.maven.org; there are scripts in the ClojureScript tree to build JARs of the G.Closure library.
09:47	thheller	dnolen: why is the :externs key outside :foreign-libs? I think it should be coupled with the foreign-lib?
09:47	_KryDos_	Hi guys. I'm learning Clojure and I need a little help. Could you please explain me the difference between (future) and (.start (Thread. ...))? And could you please give me information when I can search for answers on the similar questions. Thank you
09:47	_KryDos_	s/when/where/ - sorry
09:48	thheller	dnolen: suppose I have a deps.cljs for with a couple of foreign libs where some might be included and some not. a "global" externs might not be available
09:49	dnolen	thheller: that's just because it's the expected shape of the build description, that is, it worked this way before, this hasn't changed in 3 years. otherwise more processing required
09:50	dnolen	thheller: I don't have a problem with allowing :externs per lib but will need a patch for that
09:51	stuartsierra	_KryDos_: `future` returns a java.util.concurrent.Future, from which you can get the value returned by the code inside it.
09:51	thheller	dnolen: ok, was thinking of building a package for codemirror. there is a whole bunch of optional stuff in it, wiring all of it up via provide/require is gonna take some effort though
09:51	stuartsierra	_KryDos_: `future` uses a thread from a cached thread pool which Clojure maintains internally.
09:51	thheller	dnolen: will see how far I get
09:52	thheller	dnolen: pretty sure some of the addons require their own externs. thats why I'm asking
09:57	_KryDos_	stuartsierra: thank you so much for the answer
09:57	stuartsierra	_KryDos_: You're welcome.
10:05	dysfun	stuartsierra: just wanted to say thanks for building component. it seems like a nice way of building apps
10:05	stuartsierra	dysfun: thanks!
10:05	dysfun	although it'd be even better if you didn't fully qualify it with com.stuartsierra
10:05	dysfun	:)
10:06	stuartsierra	dysfun: I'm not going to try to claim ownership of the word "component" at the global Clojure namespace level.
10:06	hyPiRion	oh no, 16 more characters per require
10:06	dysfun	ah, point :)
10:06	justin_smith	SagiCZ1: regarding future-cancel - it won't stop the thread unless it is blocking in specific contexts (which are frequent places to catch it but not guaranteed). You can check (.isInterrupted (Thread/currentThread)) to see if your thread has been cancelled, and use that as a conditional before looping
10:07	dnolen	thheller: right, happy to take a patch for this - should only need to touch a few bits of code to make it work
10:07	stuartsierra	And I don't like names that have nothing to do with what the code actually does.
10:07	SagiCZ1	justin_smith: and if i call the future-cancel it flips the interrupt flag so at any time after that point if i ask isInterrupted it would always return true, correct?
10:07	justin_smith	right
10:08	justin_smith	and like I said, if the thread was eg. blocking on a read, it would be stopped automatically as well
10:08	justin_smith	but as you saw, that is not something you can always count on
10:09	hyPiRion	justin_smith: huh? A thread blocking on a read cannot be interrupted before it actually receives some data.
10:09	SagiCZ1	justin_smith: okay.. yeah i wrapped the isinterrupt check into a simple function whcih throws an exception.. then i catch the exception much higher in the hierarchy where i can deal with resetting progress bar etc.. its good because the exception propagation is automatic and no extra code is required.. overall i am after all pretty happy with the solution
10:09	justin_smith	hyPiRion: hmmm... let me double check my source
10:09	hyPiRion	justin_smith: http://bugs.java.com/bugdatabase/view_bug.do?bug_id=4514257
10:10	hyPiRion	You can't assume you can at least.
10:11	justin_smith	hyPiRion: I was going by this http://docs.oracle.com/javase/8/docs/api/java/lang/Thread.html#interrupt--
10:12	justin_smith	but now I see that is specific to wait, IO on InterruptibleChannel s and Selector
10:14	justin_smith	but regardless, of course, best to explicitly check interrupted status if you want future-cancel to actually work
11:39	thheller	dnolen: think we should support :source-map for :file-min in foreign-libs? some js libs provide source maps. not sure how that would work if we merge the :file-min into the build though
11:59	dysfun	i need to do live video encoding. anyone know what the state of tools for clojure is?
12:06	clgv	s/clojure/java/
12:06	TimMc	dysfun: Probably nothing clojure-specific. Try Java-land.
12:06	dysfun	yeah, i've found jcodec and i'm pondering writing a wrapper
12:11	TimMc	Does it need wrapping?
12:12	dysfun	anything that involves me writing lots of code using java method invocation syntax does, yes, for my sanity :)
12:21	tbaldridge	personally I'd try to keep as much of this out of the JVM as possible, and just do some sort of FFI wrapper around FFMpeg
12:21	noncom	dysfun: javacv is the option i think
12:21	djames_	I just posted a question about a challenge I'm facing with lots of nested functions that use destructuring to the ML. I find it convenient, but it makes memoization harder. I'm curious if others have faced this. I'm also interested in memoization.
12:21	noncom	i have a very positive experience with it
12:22	djames_	https://groups.google.com/forum/#!topic/clojure/RZE52iLY0oY
12:22	noncom	dysfun: worth noticing that javacv != opencv-for-java. it is much more. for example, it provides reach caps in playing and editing and converting video with ffmpeg
12:35	aaelony	is conj.io down?
12:36	puredanger	yes, and arrdem is aware
12:36	aaelony	thx
12:41	zacts	hum.. I'm finding I really prefer these two books the most: 0) brave clojure, and 1) O'Reilly Clojure Programming
12:46	dysfun	noncom: ffmpeg sounds like JNI hell to me
12:46	tbaldridge	for FFI stuff JNA is much easier and almost as fast.
12:48	dysfun	i'll give it a spin anyway
12:52	hiredman	swig is nice
12:59	noncom	dysfun: not at all. ffmpeg is wrapped in javacv for you already
12:59	noncom	it works very well
13:00	zacts	I want to make a music composition app with clojure
13:00	zacts	and a visual composition app
13:01	justin_smith	zacts: you could look into kunstmusik/pink, it's from one of the lead csound devs
13:01	zacts	oh neato!
13:01	zacts	also, how about ChucK?
13:01	justin_smith	it includes the signal processing stuff, and also higher level event processing too
13:02	justin_smith	ChucK is novel
13:02	devn	hola
13:02	zacts	oh cool
13:02	noncom	dysfun: here are two files for you to start with: https://www.refheap.com/96496 , https://www.refheap.com/96497 - them are from my project where I use javacv to play video on a JMonkeyEngine texture
13:02	justin_smith	if you want to target a synthesis language, csound has the most built in stuff, and has the easiest syntax to generate I think
13:03	zacts	ah ok
13:03	justin_smith	zacts: but with pink, you don't need to target another synth language, it implements its own in pure clojure
13:03	zacts	yeah, I'm a newbie in this regard
13:03	noncom	zacts: heeey, cojurists, do not forget http://overtone.github.io/ !
13:03	zacts	oh neat
13:03	justin_smith	yeah, overtone is an option too
13:03	justin_smith	it cheats by shipping supercollider in the jar :)
13:03	justin_smith	"cheats"
13:05	noncom	java minim and beads libraries could come in handy too... depending on usecase..
13:07	zacts	how about visual programming art?
13:07	zacts	like fractals / designs / etc..
13:07	zacts	I think it would be cool to combine music with the visual aspect
13:08	noncom	zacts: i think that the simplest start for you would be with processing
13:08	noncom	zacts: https://processing.org/
13:09	noncom	zacts: and from the authors of overtone, here comes a clojuric processing wrapper for you: https://github.com/quil/quil
13:10	zacts	oh cool!
13:10	zacts	brb, heading out for a sec
13:16	sorenmacbeth	is it possible to write a macro that calls a java method dynamically? im dying here
13:17	sorenmacbeth	something like (~meth ~obj ~val)
13:17	sorenmacbeth	where ~meth is a symbol like .set_something
13:18	puredanger	sure, although you'll probably want to use just . rather than .method I think
13:19	puredanger	so like (. ~obj (~setter ~value))
13:20	puredanger	I did something similar here: http://stackoverflow.com/questions/27308061/whats-the-idiomatic-way-to-do-this-java-function-in-clojure/27308254#27308254
13:27	sorenmacbeth	puredanger: yeah, like that
13:27	sorenmacbeth	that form didn't work fpr me when I tried it (at 2am)
13:28	puredanger	it doesn't work between 2-3 am
13:29	chouser	ha!
13:30	puredanger	chouser implemented that
13:30	stuartsierra	chouser: long time, no see
13:32	chouser	stuartsierra: Hi!
13:38	Glenjamin	dnolen: would it be fair to say the test.check ClojureScript port was "straightforward", i'm writing up some backstory on checkers ?
14:11	sorenmacbeth	so that works, but not if you pass in symbols
14:12	sorenmacbeth	(set-fields my-map my-options)
14:12	amalloy	sorenmacbeth: you have to use reflection. a macro can't do things "dynamically", because it emits code at compile time
14:13	sorenmacbeth	amalloy: i was afraid you where going to say that
14:14	dysfun	noncom: thanks :)
14:15	sorenmacbeth	(require '[clojure.reflect :as reflect])
14:15	sorenmacbeth	(def r reflect/reflect pv)
14:15	sorenmacbeth	f
14:15	sorenmacbeth	r
14:16	sdegutis	Does Clojure have functors?
14:16	justin_smith	sorenmacbeth: are you trying to use the bot?
14:16	sorenmacbeth	haa, this is not my REPL buffer
14:16	stuartsierra	sdegutis: In the ML module functor sense, no.
14:17	sdegutis	aww
14:17	sdegutis	What does Clojure have instead?
14:17	dysfun	sequences
14:17	justin_smith	functions that operate on protocol / multimethod methods instead of concrete types
14:18	noncom	dysfun: np. as a notice: i have used a clojure agent as a receiver of frames that a grabber grabs (to later draw on a texture), since i thought of it as of best possible concurrency model for the task.. idk if it is though.
14:18	stuartsierra	You can simulate functors in Clojure by combining protocols with some kind of dependency injection.
14:19	dysfun	noncom: in this case i'm encoding video server side so i'm basically shoving it straight back out of a pipe
14:20	tcrayford____	sorenmacbeth: hail satan
14:20	noncom	dysfun: ah, better for you then :) if you read javacv forums and docs, i bet you find much info on converting / encoding and saving video
14:21	dysfun	heh
14:24	dysfun	i haven't been able to concentrate easily this week, and i've got to present what i'm doing tomorrow afternoon, so we'll see :)
14:25	zacts	back
14:25	R0B_ROD	Hey
14:26	amalloy	sdegutis: do you mean functors in the ML sense like stuartsierra is saying, or the haskell sense?
14:26	zacts	heh, R0B_ROD I initially read your nick as ROB_FORD
14:27	zacts	sorry man
14:30	sorenmacbeth	tcrayford____: hail satan indeed
14:32	zacts	ile
14:48	sdegutis	amalloy: I only know OCaml
14:48	zacts	darn I forgot my headphones, and I'm at the cafe, so I'll have to try the overtone stuff laters
14:54	hellofunk	sdegutis: if i remember, you are the author of the great oo library OOPS, am i right? then if so, i can understand your affinity for OCaml
14:57	sdegutis	hellofunk: no, I am not the author of any great library
14:58	sdegutis	hellofunk: I have written OOPS as an experiment, although I'm surprised I haven't yet deleted it
14:58	sdegutis	hellofunk: it's certainly not in use anywhere
14:59	hellofunk	sdegutis: i was a bit tongue in cheek, though i remember your interest in OO mixed with FP and now see you've discovered OCaml which seems like a worthy exploration for your interestts.
15:01	sdegutis	hellofunk: I don't know anything about the OO part of OCaml yet. I just think dynamic typing is for toys and static typing is for serious projects, and OCaml has all my favorite Clojure features (destructuring, core.match, simple elegant syntax) and then some (polymorphic variants, etc).
15:02	hellofunk	theoretical question of the day: is it possible to express a simple average function as a single reduce?
15:02	llasram	hellofunk: yes
15:03	hellofunk	llasram: i suppose you'd keep a running count going in your reduction?
15:03	sdegutis	hellofunk: you'd probably use clojure.core/reductions
15:03	llasram	hellofunk: even better actually
15:03	llasram	sdegutis: ho ho ho
15:03	sdegutis	llasram: did I win that one?
15:03	tbaldridge	or if your input collection has O(1) count, just use that
15:03	zacts	my cat named lambda says hi
15:04	zacts	so how often do clojurists use java libraries?
15:04	justin_smith	zacts: in every project
15:04	tbaldridge	zacts: often
15:04	zacts	oh interesting
15:04	llasram	hellofunk: something like this: https://gist.github.com/llasram/5860685
15:04	justin_smith	in most namespaces
15:04	tbaldridge	every 5th thursday of the month.
15:05	sdegutis	zacts: there's no point to clojure unless you're gonna use a java lb
15:05	llasram	hellofunk: Also numerically stable, unlike naive sum + divide
15:05	dysfun	sdegutis: or...a clojure lib?
15:06	dysfun	it's not like we don't have an extensive library ecosystem by now
15:06	zacts	huh ok, so I guess I need to understand how java's OOP libraries interact with clojure's functional paradigm?
15:06	zacts	aren't the two kind of conflicting in a sense?
15:06	turbofail	there's not exactly much to understand... you call java methods when you need to using the (.foo blah) syntax
15:07	turbofail	occasionally you might need to implement a java interface
15:07	justin_smith	zacts: that comes up sometimes - eg. when a poorly designed api won't accept implementation of an interface (easy to do from clojure) but instead needs you to subclass (harder to do from clojure)
15:07	dysfun	first parameter being the object to invoke the method on
15:07	hellofunk	llasram: i see, so my initial assumption was more or less on point, that you keep a running tally of things as your reduce along
15:07	dysfun	justin_smith: potemkin makes it pretty easy
15:07	zacts	huh, cool
15:07	zacts	ok
15:08	zacts	well I'm almost to the point of learning about java interop
15:08	sdegutis	dysfun: it probably uses a java lib
15:08	dysfun	there's really not much to it
15:08	justin_smith	dysfun: wait, potemkin allows subclassing arbitrary java classes?
15:08	dysfun	sdegutis: many do, sure, but that's because we happen to be on java, just as you'd quite often integrate with a c library in ocaml land, i'm guessing
15:08	zacts	that was my biggest question, if I'm using java libs quite often, how do I not let java's non-pure functionalishness infect my clojure code
15:08	dysfun	justin_smith: deftype+
15:09	dysfun	try and keep as much as possible in clojure space, not java space
15:09	dysfun	and bear in mind that most java data are mutable and require mutation to do things, rather than returning altered copies
15:10	dysfun	so reduce and map and all of those won't work so well
15:10	zacts	hum..
15:10	dysfun	there are some macros to make it a bit less painful, like doto and ..
15:10	dysfun	,(doc ..)
15:10	justin_smith	dysfun: hmm... potemkin source indicates that it supports "abstract types", but I see nothing about it allowing the creation of a concrete subclass
15:11	clojurebot	"([x form] [x form & more]); form => fieldName-symbol or (instanceMethodName-symbol args*) Expands into a member access (.) of the first member on the first argument, followed by the next member on the result, etc. For instance: (.. System (getProperties) (get \"os.name\")) expands to: (. (. System (getProperties)) (get \"os.name\")) but is easier to write, read, and understand."
15:11	dysfun	justin_smith: deftype+ can have a provided parent class type
15:11	dysfun	justin_smith: the usual case being to inherit from an abstract class
15:12	zacts	dysfun: Hm.. I'm assuming I'll learn how this all fits together as I gain more clojure experience
15:13	zacts	so my projects I want to do: 0) make a simple text editor with clojure 1) do music synth 2) do visual fractal art with clojure
15:13	dysfun	it could be that it only works with the def-abstract-type generated classes, but i haven't had to use it since i discovered potemkin
15:13	justin_smith	llasram: dysfun: yeah I am reading the source and I see nothing that would or could do that so far...
15:14	alexyakushev	zacts: Go straight for 1) and 2); 0) is boring :O
15:14	zacts	alexyakushev: ah, ok! :-D
15:14	zacts	I'll call it yet another editor editor
15:14	zacts	(kidding)
15:14	dysfun	zacts: for your music synth project, you'll want to look at overtone
15:14	alexyakushev	Especially since Clojure already has great tools like Overtone and Quil
15:15	zacts	I'm also hoping to learn good software abstraction / design ideas from doing music synth with clojure
15:15	zacts	I'm feeling I'll get more of an intuitive sense of things
15:16	dysfun	hah, good luck with that
15:16	alexyakushev	Hey get some inspiration https://twitter.com/jackrusher/status/467571017679114240
15:17	zacts	wow that's pretty neat alexyakushev
15:17	alexyakushev	I keep this tweet in bookmarks so that I finally get to try Quil someday
15:21	zacts	so what is a good JSON alternative for clojure, is edn like this?
15:22	zacts	or should I just use clojure data structures in a text file?
15:22	justin_smith	zacts: it is easy to translate between json and edn, and also there is transit for faster network transfer
15:22	tbaldridge	edn works well, depends on your needs.
15:22	zacts	oh cool justin_smith
15:22	zacts	ah ok
15:22	justin_smith	for usage within one app, edn is great, if communicating with a client I would use json or transit
15:23	zacts	so the only issue with edn, is that it's not a tottaly stable api
15:23	tbaldridge	and if you're going JVM to JVM and clojure (or java) on both ends, Fressian is probably the fastest.
15:23	justin_smith	cheshire does a good job of translating from edn to json
15:23	tbaldridge	https://github.com/Datomic/fressian
15:23	tbaldridge	all depends on what you need.
15:23	zacts	ok neat
15:25	zacts	clojure reinvents the wheel, but it reinvents it to be a hovercraft
15:25	zacts	it's cool, although it still uses previous design lessons
15:25	tbaldridge	yeah, it learns from the stuff we all forgot 40 years ago.
15:26	zacts	so perhaps I should ask what would be a good first project to do after reading braveclojure? Can I start right away into the music processing?
15:27	zacts	oh project euler I did want to try some of those
15:35	sdegutis	So, anyone here know Haskell and have written a comparison between Clojure and Haskell to get Clojurians up to speed on Haskell? Thanks in advance, regards.
15:37	dysfun	i imagine if you google 'clojure vs haskell' you'll turn up all sorts of things like that
15:38	sdegutis	Only one from callen
15:38	raek	sdegutis: do you happen to know another language from the ML family?
15:39	hellofunk	sdegutis: i've seen a number of articls on the subject. google was my friend at the time, but you may choose an appropriate alternative as your friend if desired.\
15:39	sdegutis	raek: I started learning OCaml and stopped at Functors because it got too confusing to learn just by looking at code examples
15:39	hellofunk	sdegutis: i wonder if they are anything like c++ functors, probably not
15:40	dysfun	they are not
15:41	dysfun	http://www.catonmat.net/blog/on-functors/
15:41	raek	it's funny that so many languages use the name "functor" for so completely unrelated concepts
15:41	justin_smith	sdegutis: functors are like functions, but they operate on modules. To understand why they can't just be functions, you need to understand why modules can't just be normal data.
15:41	justin_smith	it's a wrinkle in ml, imho
15:41	dagda1_	is there any difference between (if (empty? []) or (if (seq [])) I see both ways used. Is there any real difference
15:42	hellofunk	dagda1_: well obvious they are opposite tests
15:42	justin_smith	dagda1_: they are opposite conditions
15:42	justin_smith	hehe
15:42	hellofunk	,(doc seq)
15:42	clojurebot	"([coll]); Returns a seq on the collection. If the collection is empty, returns nil. (seq nil) returns nil. seq also works on Strings, native Java arrays (of reference types) and any objects that implement Iterable."
15:42	raek	sdegutis: There's a guide called "A Gentle Introduction to Haskell". It does not compare Haskell to Clojure though.
15:42	hellofunk	oh that didn't have the extra bit that i find useful in the seq docstring
15:42	sdegutis	thanks
15:42	tbaldridge	And as a favorite language developer of mine said once "If you start trying to implement parameterized namespaces, suddenly you realize that it breaks REPL development, because modules become the unit of compilation instead of the form being the unit of compilation"
15:42	justin_smith	,(doc empty)
15:42	clojurebot	"([coll]); Returns an empty collection of the same category as coll, or nil"
15:43	justin_smith	,(doc empty?)
15:43	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))"
15:43	justin_smith	that's the one
15:43	dagda1_	ha right, maybe the penny just dropped
15:43	raek	sdegutis: I found it useful to learn about the basic concepts and their syntax. (I came from Clojure and Standard ML.)
15:43	hellofunk	justin_smith: yep that's what i was looking for
15:43	sdegutis	raek: :)
15:43	sdegutis	I'm probably going to turn into one of those Haskell people for some reason.
15:44	raek	it doesn't teach you how to "think in Haskell", but I found it useful as a reference manual
15:44	sdegutis	Probably a lot because of callen's testimony: http://bitemyapp.com/posts/2014-04-29-meditations-on-learning-haskell.html
15:45	amalloy	i mean, haskell is pretty cool. you don't have to become "a haskell person". you can enjoy both
15:45	turbofail	unless you're callen
15:45	raek	sdegutis: both Clojure and Haskell are nice languages... you don't have to abandon one for the other
15:46	hellofunk	sdegutis: i am quite enamoured with the theories of math and how they intersect with programming, and haskell seems to be the great example of that. Even Sussman thinks haskell is the "greatest of the obsolete languages" (he thinks all programming languages today will soon be obsolete)
15:46	dysfun	i don't think he's wrong
15:47	dysfun	do you think we'll still be writing code in 20 years?
15:47	hellofunk	dysfun: i do.
15:47	dysfun	i do not
15:47	justin_smith	people still use lisp, fortran, and cobol, three of the oldest languages
15:48	turbofail	20 years isn't all that much time for such a drastic change in how we control computers
15:48	hellofunk	turbofail: exactly. now, 200 years, that's a different bet
15:48	dysfun	once we figure out how we can get rid of bizarre languages and communicate more clearly with the computer, development will improve apace
15:48	hellofunk	dysfun: i doubt that will happen in just 20 years
15:48	dysfun	we'll see :)
15:49	tbaldridge	to put it into perspective, Python has been around for 24 years.
15:49	hellofunk	and the origins of computing itself, as a theory and idea, are approaching a century old now.
15:49	nuwanda_	dysfun: we'll be maintaining a bunch of code bases we're creating now in 20 years :) imho
15:49	hellofunk	well, the modern idea of computing, anyway
15:50	stuartsierra	Haven't people been predicting the demise of programming languages ever since the invention of programming?
15:50	dysfun	nuwanda_: that too :)
15:50	hellofunk	stuartsierra: much like the constant exaggerated claims every few years across all of time about the impending doom or mystiquie of AI. recently there was another spattering of high profile claims. it's ridiculous.
15:51	dysfun	stuartsierra: moore's law held for long enough that it's possible
15:51	sdegutis	hellofunk: dunno who sussman is but ok
15:51	hellofunk	sdegutis: you heard of SICP?
15:51	sdegutis	oh yeah
15:51	hellofunk	sdegutis: he's an author of that. MIT professor. quite influenctial.
15:51	sdegutis	i imagine that guy loves dynamic typing then
15:51	hellofunk	sdegutis: he's a big fan of haskell, but clearly his background is much in lisp.
15:52	sdegutis	i imagine he wants a more dynamic, lispy haskell then
15:52	tbaldridge	I would sit and listen to Sussman for hours if I had the chance.
15:52	hellofunk	sdegutis: no, you're not going far enough.
15:52	dysfun	or a more typesafe lisp
15:52	dysfun	(which is what i want)
15:52	sdegutis	meh, i have no love for macros
15:52	hellofunk	no he thinks all manner of computing today is very far from the ideal power that could be available.
15:52	tbaldridge	Any man who is both an expert programmer and an expert watch maker is pretty awesome IMO.
15:53	dysfun	preferably with a touch of slightly clearer syntax on top. haskell does a reasonable job there
15:53	sdegutis	tbaldridge: easy there buddy, hes just a human like you and me
15:53	hellofunk	tbaldridge: let's not forget his prowess with electronics
15:53	sdegutis	;)
15:53	tbaldridge	yeah, that too.
15:54	noonian	you can find the sicp lectures on youtube, sussman is very fun to listen to because he's always excited about what he's teaching
15:54	hellofunk	noonian: i just watched one of this recently, my first. in the beginning i was like, "who is this cliche wearing a pocket protector and flip-up glasses?!" then i realized who he was and was like, dang, son, i'm gonna go get me a pocket protector imminently!
15:55	noonian	hellofunk: lol
15:58	dysfun	i never saw a need for a pocket protector anyway, but then by the time i grew up, we'd stopped using slide rules
15:58	dysfun	we did use fountain pens, but it was such a rare ocurrence to get a leak...
15:59	noonian	i never knew what a pocket protector protected one from until this moment
16:01	dysfun	these days noone carries a pen anymore
16:02	ordnungswidrig	dysfun: the pocket protector picure at wikipedia is weird.
16:04	puredanger	Sussman took the Haskell workshop when he did the keynote at Strange Loop (iirc it was Bryan O'Sullivan teaching)
16:04	puredanger	paraphrasing, he said "those people are weird"
16:05	dysfun	ordnungswidrig: why? because it's got a tux on it?
16:07	ordnungswidrig	dysfun: absolutly. I only know them blank and "reluctant"
16:08	dysfun	pretty sure if you wore a pocket protector at my old school you'd've had your head kicked in
16:09	ordnungswidrig	I still use a fountain pen but never carry it in a shirt pocket. I had no accident ever.
16:16	samiswellcool	I carry a whole case of pens
16:16	samiswellcool	and my current notebook and my last notebook
16:27	aaelony	I'm confused by clj-time: (clj-time.coerce/from-long (long 1418813990)) gives me #<DateTime 1970-01-17T10:06:53.990Z>, but http://www.epochconverter.com gives me GMT: Wed, 17 Dec 2014 10:59:50 GMT (which is correct) for the same value.
16:30	justin_smith	aaelony: is from-long doing a ms or ns conversion?
16:30	justin_smith	try adding three zeroes to the end
16:30	chouser	,((get get get get) (get get get get) (get get get get) 5)
16:30	clojurebot	5
16:30	justin_smith	lol
16:30	aaelony	justin_smith: thank you.
16:30	aaelony	that works now
16:34	Glenjamin	,(def get out)
16:34	clojurebot	#<CompilerException java.lang.SecurityException: denied, compiling:(NO_SOURCE_PATH:0:0)>
16:34	sssilver	Hey guys, what does this Clojure snippet calculate? Any clue? (defn fact [n] (reduce * (range 1 (inc n))))
16:34	sssilver	let me rephrase that... does that look like a correct implementation of factorial?
16:34	amalloy	hellofunk, did you notice http://stackoverflow.com/questions/28131135/how-to-implement-zip-with-foldl-in-an-eager-language ?
16:35	amalloy	sssilver: try it on a few numbers and see?
16:35	justin_smith	sssilver: it would take 1 through n inclusive, and take each item in that list and multiply it by the previous total (starting with 1*2)
16:35	sssilver	amalloy: I don't have clojure on my machine
16:35	amalloy	,(map (fn fact [n] (reduce * (range 1 (inc n)))) (range 1 8))
16:35	clojurebot	(1 2 6 24 120 ...)
16:36	amalloy	&(map (fn fact [n] (reduce * (range 1 (inc n)))) (range 1 8))
16:36	lazybot	⇒ (1 2 6 24 120 720 5040)
16:36	amalloy	there is an abundance of online clojure evaluators, for example http://www.tryclj.com/ if you want to play around without installing anything
16:37	sssilver	cool, thanks guys
16:39	Glenjamin	hrm, my mobile friendly PR got merged, but it doesn't look like tryclj is updated yet
16:41	Glenjamin	amalloy: i'm really confused by that answer, foldl :: (a -> b -> a) -> a -> [b] -> a - but the answer has 3 args to the folding function
16:41	amalloy	Glenjamin: it's folding up into another function
16:41	amalloy	ie, the accumulator is itself a function
16:41	Glenjamin	oh
16:42	amalloy	a ~ (c -> d)
16:42	Glenjamin	aha, so it is
16:42	Glenjamin	i find it really annoying having haskell arguments not named >.<
16:42	amalloy	what do you mean?
16:43	justin_smith	Glenjamin: aka point free style?
16:43	Glenjamin	(a -> b -> a) -> a -> [b] - took me a min to figure out which was which
16:44	Glenjamin	and yeah, the point free doesn't help massively, i only just realised the ys is applied to the folded function
16:44	Glenjamin	oh, and so is the (const [])
16:45	amalloy	well this like...isn't point-free style at all
16:45	Glenjamin	well, as i think about it more, the lack of parens is my problem
16:45	amalloy	he could have even removed the 'ys' argument, since applying it at the end is unnecessary: zip1 xs = ... (const [])
16:46	Glenjamin	which is odd really, as i learnt haskell before any lisps
16:48	amalloy	the translation of that haskell to clojure is not really made more readable by all the parens: https://www.refheap.com/37b61066156c2265969b7dd89
16:48	Glenjamin	haha
16:49	Glenjamin	i think separating the reduce into a function from the unrolling would help
16:49	Glenjamin	in the haskell version also
16:50	tbaldridge	amalloy: this is the code for the "multi arity map" thing from the other day, right?
16:50	amalloy	tbaldridge: yeah
16:50	amalloy	well, this is the implementation of zip, which is "the hard part" of multi-arity map
16:51	tbaldridge	from what I saw of the haskell code the other day, aren't they just turning the second collection into nested closures? If so, then why not use lazy-seqs?
16:52	amalloy	tbaldridge: my goal in finding this was to refute the claim that you can't do multi-arity map as a reduce. i'm not claiming this is a good implementation of zip that you would actually use
16:53	amalloy	i don't totally see how you would use lazy seqs instead of these nested closures; you can't really be lazy anyway, when you're reducing
16:53	hellofunk	amalloy: i'm glad to see you are still thinking about this. i spent the weekend reading about foldl and foldr and really understanding them as much as i can. i was thinking about continuing our conversation on that but am not well enough versed yet
16:53	hellofunk	amalloy: lots of old threads on the clojure mailing list about this, of which you participated, some going back five years
16:54	amalloy	haha, do share. i don't remember most of the things i said
16:54	Glenjamin	i'm not sure that this nested closure solution is really different from the (reverse)
16:54	hellofunk	my general motivating factor, a theoretical musing perhaps, is the notion of a higher level to HOFs
16:54	Glenjamin	doesn't it still effectively do two traversals?
16:56	amalloy	well uh...probably. i can't really tell what's going on tbh
16:56	amalloy	but it's all one big fold! that was all i was after
16:57	tbaldridge	amalloy: I always assumed multi-arity map could be done like this: https://www.refheap.com/96507
16:57	hellofunk	amalloy: i agree, the idea of folding in general, at the purest level, excites me, especially when a fold can be the composite of many folds, all of which have the same higher structure to each
16:59	amalloy	tbaldridge: that does seem a lot simpler
16:59	amalloy	though you want to replace [[] ys] with [[] (seq ys)]
16:59	tbaldridge	I don't think one is better than the other TBH. They both transverse twice, they both do allocation during reduction.
16:59	sdegutis	Is it bad practice to use :otherwise in a cond instead of :else?
16:59	sdegutis	(as the last case)
16:59	Glenjamin	dammit tbaldridge, i was just typing that
17:00	Glenjamin	but mine doesn't work yet :)
17:00	justin_smith	sdegutis: I prefer :YOLO
17:00	Glenjamin	(inc justin_smith)
17:00	lazybot	⇒ 172
17:00	sdegutis	justin_smith: whence all dat karma bruh
17:01	amalloy	justin_smith: hyphenated keyword-haiku
17:01	justin_smith	sdegutis: I stole it when technomancy wasn't looking
17:01	samiswellcool	Would you recommend just using clojure.test to write tests?
17:01	hellofunk	amalloy: unless it's me, the word "zip" seems quite overloaded
17:01	sdegutis	Too bad about him, up and leaving #clojure like that.
17:01	justin_smith	samiswellcool: yeah, clojure.test is good
17:01	amalloy	(cond x y, a b, :Light-of-the-moon-Moves-west-flowers-shadows-Creep-eastward "not found")
17:02	justin_smith	(inc amalloy)
17:02	lazybot	⇒ 216
17:02	Glenjamin	i had https://www.refheap.com/96508
17:02	Glenjamin	took me 3 goes to remember that i needed the & to destructure
17:04	amalloy	tbaldridge: do you mind if i post your clojure solution as another answer to that SO question? or you can do so yourself
17:05	tbaldridge	amalloy: please do
17:06	zacts	ooh, I want to make an RPG game too
17:06	Glenjamin	is there a strong reason to prefer first/next vs [x & xs] ?
17:06	zacts	but mine will be simple
17:07	hellofunk	amalloy: further to the point is the recent article i read somewhere about how foldl and foldl' are both expressable as foldr, making foldr the higher level
17:07	amalloy	hellofunk: sure. you can also express foldr as foldl, if you don't mind giving up laziness
17:09	hellofunk	amalloy: no, the opposite. foldl as foldr
17:09	amalloy	hellofunk: right, i mean you can go either way
17:09	amalloy	but if you implement foldr using foldl you can't be lazy
17:11	hellofunk	amalloy: the other issue that got me curious is the idea of the consumer function. it should be able to evolve during the folding to create interesting patterns. like the consumer is feeding back on itself as a minifold within the larger fold
17:19	amalloy	tbaldridge: http://stackoverflow.com/a/28159764/625403
17:23	amalloy	hellofunk: try picking up haskell, then. it's less hard if you already understand functional programming, although still foreign enough to teach you some new ways of thinking
17:24	hellofunk	amalloy: the syntax makes my eyes hurt
17:24	amalloy	hellofunk: complaining about that makes you a big baby, if you'll pardon my rudeness. people say the same thing about lisp all the time and clojure folks scoff at them
17:25	amalloy	surface syntax is an easy thing to complain about, but not terribly important
17:25	hellofunk	amalloy: fair enough, but it's still true. after staring at lisp all day, when you see haskell my eyes aren't trained to know where the expressions are delinieated
17:25	amalloy	sure. i had the same problem too, sometimes still do. the solution is practice, like with anything else
17:25	metellus	hellofunk: isn't that something you'd get over pretty quickly as you used the language?
17:26	hellofunk	sure, but i don't use it, but as an example comparison, i also don't use java, having never written a line of it in my life, but somehow java is straightforward to read while haskell, well, my ignorance hurts my eyes
17:27	turbofail	i still have trouble making sense of scala syntax sometimes
17:27	turbofail	actually i have more of a problem with writing scala than reading it
17:27	hellofunk	i feel like i have been spoiled by lisp syntax
17:28	turbofail	it's often not clear to me why something i've written in scala is a syntax error
17:29	tcrayford____	anybody got any idea why ring.util.codec/url-encode doesn't encode "," as "%2C" ?
17:29	amalloy	tcrayford____: why would it?
17:30	tcrayford____	because , isn't a valid url part according to compojure haha :(
17:30	hellofunk	amalloy: just came across this and interestingly turbofail you are quoted in it: https://gist.github.com/hellofunk/a1582981ecafa6b36e63
17:30	tcrayford____	aka /some-user-defined-path had a "," in it, and compojure just 404s haha
17:30	amalloy	well, it depends what part of a url, right. like it's valid in a query, but not in a path part
17:31	tcrayford____	right
17:31	amalloy	hellofunk: i mean, java is like super inexpressive: there is a ton of redundant information, lots of whitespace, and a very regular structure
17:32	tcrayford____	amalloy: is there a better alternative to url-encode from ring.util.codec for encoding path-parts?
17:32	turbofail	ah yeah i remember that discussion
17:32	turbofail	that was in #emacs
17:33	hellofunk	amalloy: do you have a tip for a quality quick start read in haskell? i can't invest much time but would like to get to the heart of the basics in a hurry without leaving serious parts out
17:33	amalloy	tcrayford____: actually , is valid in a path part. i was just assuming that it's not because you are having trouble with it
17:33	uptown	hello out there. i'm trying to retrofit midje into a project which had no tests but despite creating the correct diretory tree, "lein midje :autotest" doesn't find my tests. when autotest starts, it logs loading the source ns but not the test ns. has anyone run across this? i can't find the configuration magic...
17:33	amalloy	if compojure is having trouble serving routes with a , in them, you might just need to adjust what regex it uses in GET
17:33	tcrayford____	amalloy: guess this is actually a problem with clout then :/
17:34	tcrayford____	amalloy: no regex haha
17:34	tcrayford____	just :thingy
17:34	amalloy	tcrayford____: i mean, it uses a regex to match this stuff
17:34	amalloy	and you can customize what regex is used
17:35	tcrayford____	amalloy: got a pointer to that? (this is literally a production bug for an customer)
17:36	amalloy	i think it's just (GET ["/pages/:foo" :foo #"[\w_,]+"] ...)
17:37	amalloy	but see https://github.com/weavejester/clout/blob/master/src/clout/core.clj#L108 for details, and note that the stuff after the url in a vector there gets mushed into a hashmap and passed to route-compile
17:37	amalloy	and of course use a different regex
17:38	tcrayford____	ta
17:38	amalloy	it looks like https://github.com/weavejester/clout/blob/master/src/clout/core.clj#L91 incorrectly excludes , from the characters it's willing to match in a path
17:40	amalloy	$mail weavejester it looks like https://github.com/weavejester/clout/blob/master/src/clout/core.clj#L91 incorrectly excludes , from the characters it's willing to match in a path, given the characters that are allowed in a path (see http://stackoverflow.com/a/4669755/625403 for one listing of such)
17:40	lazybot	Message saved.
17:40	amalloy	i guess i should make a github issue but...irc is so nice
17:40	tcrayford____	I'm filing
17:45	tcrayford____	see https://github.com/weavejester/clout/issues/23
17:45	tcrayford____	amalloy: ^^
17:45	tcrayford____	thanks btw
17:46	amalloy	tcrayford____: did the suggested workaround work?
17:46	tcrayford____	not tried it yet
17:47	amalloy	hellofunk: LYAH is pretty great. a bit slow but fun
17:47	tcrayford____	think I'm just gonna wrap up my own encoder that escapes ,
17:54	tcrayford____	amalloy: I'm unsure why compojure/ring even do their own url munging regex stuff :/
17:54	tcrayford____	java has url encoding stuff in the stdlib
17:56	amalloy	well, clout has to understand the urls
17:56	amalloy	and java.net.url is pretty dreadful
17:58	amalloy	but even if you built a url successfully and called getPath on it, you'd still need to parse out the path parts, which is the code that's currently not working
17:58	tcrayford____	ah, gotcha
18:00	samiswellcool	I feel like I'm relying too heavily on loop and recur
18:01	amalloy	you're probably not wrong, samiswellcool
18:06	amalloy	with some examples somebody could help you rewrite, but in general you probably should be using reduce or lazy sequences most of the time
18:10	samiswellcool	I'm new enough to clojure that 'it works' is enough of a motivator for now, but I'm going through what I've done so far every now and again and refactoring parts away from recurring loops
18:20	Glenjamin	amalloy: is anything about loop..recur particularly worse than using reduce?
18:21	amalloy	Glenjamin: well. is anything better about map than writing for (i = 0; i < xs.size(); i++) {xs.get(i).whatever();}? reduce has the bookkeeping logic already written for you, so it doesn't muddy up the particular thing you're doing
18:22	Glenjamin	ah right, makes sense
18:22	Glenjamin	i was thinking they were equivalent, but forgetting you still need to split head/tail when loop ing
18:27	tbaldridge	also, reduce is much faster for vectors and reduce-kv is faster for maps
18:27	tbaldridge	less allocation that way
18:44	eriktjacobsen	Ok Macro wizards! I have a recurive macro problem… Since the failure conditions aren’t known at expansion time, I understand why I get a stack overflow error… I’m having trouble visualizing how to break this apart though… helper functions? some sort of loop-recur inside the macro? http://pastebin.com/Th2uB2gU
18:45	eriktjacobsen	the macro itself splits the first argument on thrown error into two smaller groups and runs them separately. I want that process to continue until it is running singles… but if I try to wrap the macro around each half-call, obviously it breaks.
18:46	eriktjacobsen	I’m still starting with macros, so visualizing how to break that into a helper function while maintaining what is a symbol, what is evaluated and what returns as a list is fuzzy for me
18:49	amalloy	so this doesn't look like a macro problem at all, eriktjacobsen
18:49	amalloy	you just want a function that takes a function and some args
18:50	amalloy	(defn split-retry [f main-args more-args] (try (apply f main-args more-args) (catch Exception e (if whatever (split-retry f (first-half-of main-args) more-args)))))
18:52	eriktjacobsen	My first intention was there was already a ton of code, so wanted something I could just wrap things… but if I did your way I could still make macro that just passed the body into that fn… yeah I way overcomplicated that
18:52	eriktjacobsen	Thanks. Got stuck in the weeds
18:54	hellofunk	eriktjacobsen: it is a right of passage in clojure/lisp, the abuse of macros when you first learn the language.
18:54	hellofunk	that should be "rite"
19:07	Glenjamin	that code sample is making me imagine a brute force macro
19:08	Glenjamin	which keeps modifying the input until it stops throwing exceptions
19:09	Raynes	If you put monkeys in a room with typewriters, eventually they'll produce Shakespeare
19:10	Glenjamin	i saw a toy language once that deleted your code if it errored
19:10	Glenjamin	like, from the disk
19:10	Glenjamin	https://github.com/munificent/vigil
19:11	amalloy	Glenjamin: https://github.com/mattdiamond/fuckitjs
19:11	Glenjamin	the support section is a nice touch
19:25	eriktjacobsen	Glenjamin: Unfortunately, that is not far from the truth. I also have some code that randomly picks dates between 2005 - 2008 to get around same issue…. Its a google API, fyi
19:26	eriktjacobsen	It randomly fails without any error messaging, even on same input… even with retries. Totally inconsistent, a list of ids that failed today for several hours would work the next day, etc
19:47	{blake}	Running under Windows (have to test IE) I find that access is denied when I try to open any port with "lein ring server". Python and Smalltalk can open ports with no difficulty.
19:48	{blake}	Could it be a Java thing?
19:51	rplevy	Any thoughts on alia vs cassaforte? They seem pretty similar.
19:51	{blake}	(Running in a corporate environment and situation suddenly changed, so suspecting some kind of remote administration shenanigans, but want to make sure.)
19:56	{blake}	Crap. It's ONLY Clojure? How is that even possible?
20:07	Glenjamin	{blake}: check your firewall settings
20:08	{blake}	Glenjamin: Local firewall isn't running. I can open the port (3000) with Java, Python, Smalltalk.
20:08	amalloy	{blake}: what is some actual code you are running and what is it doing
20:08	Glenjamin	that's the extent of my windows knowledge i'm afraid. Maybe check java security settings?
20:09	amalloy	nobody wants to play twenty questions to narrow down all possible network failures, when you have a specific failure in front of you
20:09	{blake}	Glenjamin: Weirdly, I just threw up a Java server and it works just fine.
20:09	{blake}	amalloy: I'm running "lein new compojure app".
20:10	{blake}	I get "Started server on port 3000" followed immediatel by "Exception in thread "main" java.io.IOException: Failed to open http://localhost:3000/. Error message: Access is denied."
20:38	insamniac	{blake}: You have no windows network security things running?
20:40	insamniac	and has your hosts file been investigated?
20:52	R0B_ROD	Evening!
20:52	R0B_ROD	Is the 540MB NetBeans IDE worth it at all for clojure??
20:52	lazybot	R0B_ROD: Definitely not.
20:53	R0B_ROD	Ok thanks lazybot
20:53	amalloy	chuckle
20:53	justin_smith	R0B_ROD: for IDE experience, I think cursive with intellij idea is likely the best right now
20:53	R0B_ROD	Total newbie here
20:53	amalloy	bots make some funny conversations. i dunno if netbeans is any good, but you probably shouldn't blindly take lazybot's advice
20:53	justin_smith	would lazybot every answer yes to two question marks??
20:53	lazybot	justin_smith: What are you, crazy? Of course not!
20:54	amalloy	lazybot: if your friends jumped off a bridge, would you do it too???
20:54	lazybot	amalloy: Yes, 100% for sure.
20:54	amalloy	i love this guy
20:54	turbofail	what about now??
20:54	lazybot	turbofail: Uh, no. Why would you even ask?
20:54	R0B_ROD	am I brainacid??
20:54	lazybot	R0B_ROD: What are you, crazy? Of course not!
20:54	R0B_ROD	am I brainacid?
20:54	R0B_ROD	...
20:54	TEttinger	brainacid???
20:54	lazybot	TEttinger: Oh, absolutely.
20:56	R0B_ROD	Sure???
20:56	lazybot	R0B_ROD: Yes, 100% for sure.
20:56	R0B_ROD	lazybot: You are correct!
20:57	R0B_ROD	Well since I dont know what Im getting into yet, I have LightTable for now. Havent 'really' used it yet.
21:09	elarson	Is there a let* clojure?
21:10	justin_smith	elarson: let already acts like common lisp let*
21:10	elarson	ah ok, thanks!
21:10	justin_smith	,(let [a 0 b (inc a) c (inc b)] c)
21:10	clojurebot	2
21:20	gfredericks	,(def x 5.975884771000674E307)
21:20	clojurebot	#'sandbox/x
21:21	gfredericks	,(Math/toRadians x)
21:21	clojurebot	1.0429886497374912E306
21:21	gfredericks	,(Math/toDegrees (Math/toRadians x))
21:21	clojurebot	Infinity
21:21	gfredericks	,(* 2 x)
21:21	clojurebot	1.1951769542001347E308
21:21	gfredericks	^ x is not close to the max double
21:23	gfredericks	huh; the javadocs say both methods are "generally inexact"
21:25	Blake2	insamniac: The security's all taken care of elsewhere. But I haven't checked the HOSTS file out, maybe I fiddled with it. Thanks!
21:26	Blake2	Which is sort of like "funny lookin' in a general sort of way".
21:39	dweave	I’m trying to better understand how macros should be used. It seems like most advice is something like “Macros should be avoided whenever possible”. It’s always POSSIBLE. Right? A prime example is probably compojure. Couldn’t routes be defined using types implementing a ‘view’ interface much the same way we do in rails/django type frameworks.
21:40	dweave	why do compojure and other libraries chose to use macros for these types of things
21:40	elarson	I'm positive this is a dumb question, but... are there some functions for reading from a file handle? specifically I'm looking at reading the input stream from a java Process object and wanting to write to the input.
21:40	dweave	elarson slurp
21:41	elarson	dweave: I'll take alook
21:41	elarson	*a look
21:41	TEttinger	(doc slurp)
21:41	clojurebot	"([f & opts]); Opens a reader on f and reads all its contents, returning a string. See clojure.java.io/reader for a complete list of supported arguments."
21:41	justin_smith	slurp works if you want to block until the stream closes
21:41	justin_smith	if you want to read output from a proc as it is available, you want to do something different than slurp
21:41	oskarkv	elarson also maybe take a look at http://clojuredocs.org/clojure.java.io
21:42	elarson	justin_smith: right, that would be my concern.
21:42	elarson	oskarkv: that looks much closer to what I was thinking. Thanks!
21:43	justin_smith	if it's a fairly long running process, to get output as it is available, you can use the .read method on the thing and read into a buffer
21:43	justin_smith	I don't think anything in clojure.java.io will help with that
21:44	elarson	justin_smith: that should be OK. I'm just checking for a password prompt
21:44	justin_smith	ahh - yeah password prompt means you definitly want .read, since even an abstraction like line-seq would fuck that up (prompt does not end with a newline)
21:45	elarson	I'm assuming that something like (.write (clojure.java.io/writer (:in proc) "hello")) would work as expected
21:45	justin_smith	elarson: you would also want to flush it (usually newline flushes but I am not as sure about process input)
21:46	elarson	justin_smith: ok, that is also something I was thinking might be necessary :)
21:46	amalloy	so uh, i have to say that doing this from clojure by hand looks a lot harder than using `expect` or something
21:47	elarson	justin_smith: btw, thanks for consistently responding to my questions. I hope they aren't so obvious as to assume I'm avoiding RTFM
21:48	elarson	amalloy: I'll take a look at `expect` as well
21:48	justin_smith	I still think about making an expect like tool in clojure sometimes
21:56	amalloy	i expect that the best part of writing your own expect variant would be all the wordplay options it opens up
22:06	oskarkv	dweave I'm not familiar with compojure. Could you provide another example? :P
22:14	TimMc	expclject
22:15	TimMc	ecjpectl
22:15	amalloy	TimMc: that sounds like a botched magic spell
22:17	TimMc	ajjume
22:18	amalloy	now you're just typing sneezes
22:18	TimMc	all the best library names happen that way
22:18	TimMc	also
22:18	TimMc	&(format "lib-%04d" (rand-int 1e4))
22:18	lazybot	⇒ "lib-6971"
22:32	notbrent_	if you happen to be in vancouver, canada, i'm organizing a clojure/clojurescript meetup on feb 5 at 6pm to try to revive the meetup group: http://www.meetup.com/Vancouver-Clojure/events/220103236/
22:56	jonh	/close
22:58	dnolen	Om contributions welcome, just me an email to request a CA https://github.com/swannodette/om#contributing
22:58	dnolen	er, "just send me"
23:00	TEttinger	I'm glad the clojure community is so friendly
23:11	mercwithamouth	can anyone tell me if the clojure for the brave book offers more than the web version?
23:12	mercwithamouth	i've planned on buying it just to support...he gives an excellent introduction...
23:17	puredanger	afaik, it's same content. but you could just ask Daniel, he is a friendly guy. :) He's @nonrecursive on Twitter.
23:18	mercwithamouth	puredanger: ok. either way purchasing...it's a really enjoyable book...
23:20	mercwithamouth	also the web development lispcast package...does anyone know what sort of app he makes?
23:30	szatz	It seems like it is more idiomatic to access map elements with the key preceding the map, such as (:some-key some-map), but Clojure also proudly totes complex keys. Isn't this preceding key problematic because it could clash with an external function name?
23:30	justin_smith	szatz: :some-key cannot clash with a function name
23:30	justin_smith	it is a keyword
23:31	szatz	Well... You can use things that aren't :-prefixed as keys, too, is what I'm getting at.
23:31	justin_smith	no
23:31	justin_smith	not as lookup
23:31	justin_smith	well, OK symbols work, but nothing else
23:31	justin_smith	szatz: clojure decides what to invoke based on what is next to the open paren
23:31	justin_smith	:keyword invokes get
23:32	justin_smith	'symbol will too
23:32	justin_smith	but a function will be called
23:32	justin_smith	,(seq {seq 1})
23:32	clojurebot	([#<core$seq__4091 clojure.core$seq__4091@2d973d4f> 1])
23:33	justin_smith	,({seq 1} seq)
23:33	clojurebot	1
23:33	szatz	Hmm... OK, so ("justin" {"justin" "smith"}) is invalid, but ({"justin" "smith"} "justin") is fine, yet the former is more idiomatic, were it to use a key instead. Does that sound about right?
23:34	amalloy	szatz: you only look up keywords that way
23:34	justin_smith	szatz: if your keyword is a literal, put it in the first position
23:34	amalloy	see http://stackoverflow.com/a/7037211/625403 for a philosophical answer
23:34	justin_smith	,('or-symbols '{or-symbols true}) ; but this is more rare
23:34	clojurebot	true
23:36	alexyakushev	,('nowai '{nowai jezaz})
23:36	clojurebot	jezaz
23:36	alexyakushev	Who ever does that?
23:36	justin_smith	alexyakushev: nobody, but it is worth knowing about because it makes a specific error message easier to understand
23:37	justin_smith	,('+ 1 2 3)
23:37	clojurebot	#<ArityException clojure.lang.ArityException: Wrong number of args (3) passed to: Symbol>
23:37	justin_smith	,('+ 1 2) ; or lack of error message...
23:37	clojurebot	2
23:38	alexyakushev	Yes, that thing I remember reading somewhere
23:38	szatz	justin_smith, amalloy: Thanks for the info!
23:39	amalloy	i actually have ('foo x) in the source file i have open right now
23:40	justin_smith	first I've heard of using it intentionally
23:40	amalloy	i can't remember doing it very many other times, but sometimes a map wants symbols for keys, and when it does, you might as well look them up that way
23:40	justin_smith	fair enough, yeah
23:41	alexyakushev	only because of the cognitive gap I would use (get...) in that case
23:41	alexyakushev	takes everyone to new symbol semantics to immediately grasp what's going on
23:41	alexyakushev	s/new/know/
23:53	szatz	Another question if you guys are still around; In ClojureScript, since it's single-threaded, I'm guessing the main benefit of using reducers would be the lack of intermediate collections from a chain of higher-order functions. Is there much more to it than that?
23:54	amalloy	szatz: that's the main benefit on the jvm too. parallel fold is a fringe benefit really
23:56	szatz	Ahh, OK, because the parallelization isn't always guaranteed (associativity required), but the removal of intermediates is, right?
23:56	amalloy	plus, most of the reducing you do is actually on small collections anyway
23:57	justin_smith	it's also that the overhead of going parallel can be smaller than the gains it provides (with smaller inputs in particular)
23:57	amalloy	like you reduce over a four-item map, or a vector with a couple dozen items
23:57	justin_smith	err, s/smaller/bigger
23:57	amalloy	man i tried subbing out the wrong "smaller", got even more confused
23:58	justin_smith	amalloy: notice that there was no /g - only subbing the first instance
23:58	amalloy	yeah but i refuse to believe that anyone does that on purpose
23:59	szatz	Right, right. You guys are handy. Thanks again.