#clojure – 2015-09-12

2015-09-12

00:17	kavkaz	justin_smith: Ah flyspell-popup is nice, I like it, thanks
00:18	kavkaz	good for the markdown side of my emacs usage
00:20	kavkaz	Is it okay to shadow the top-level parameter name with a parameter name in a letfn function definition? Given that they both refer to the same variable of course
00:27	mungojelly	is the clojure grammar too simple for anyone to have bothered saying it as BNF? i like BNF i'd like to see it just to make sure i'm not missing anything
00:35	mungojelly	here it is in ANTLR https://github.com/antlr/grammars-v4/blob/master/clojure/Clojure.g4 so i guess i'm satisfied :)
03:52	felipedvorak	So I have finally succeeded in answering Project Euler problem number 1 with Clojure, but now I was wondering if someone could read the code and criticize it for me. I'm worried if this is functional or not, and if the solution is too bizare.
03:52	felipedvorak	http://pastebin.com/rYZb8mVT
03:53	felipedvorak	You must get a sum of the numbers below 1000 that are divisible by 3 or 5.
03:53	felipedvorak	sorry someo*one but you probably have alerts turned off anyway...
03:54	kungi	felipedvorak: I can help you a little
03:55	kungi	,(reduce + [1 2 3 4])
03:55	clojurebot	10
03:55	felipedvorak	kungi: thanks
03:55	kungi	felipedvorak: you can use + directly in your reduce
03:55	felipedvorak	wow, I tried that but somehow it didn't work :/
03:55	felipedvorak	but I had some problems with paredit earlier, it may be that it was the culprit of the errors
03:56	kungi	felipedvorak: yes paredit can be a huge problem first
03:56	kungi	felipedvorak: why does create-range have to return a vector?
03:57	felipedvorak	kungi: don't know hauhauh
03:57	felipedvorak	I'm with the impression vectors are more consistent
03:57	kungi	felipedvorak: consistent?
03:58	kungi	felipedvorak: instead of (reduce + [1 2 3]) you can also write (apply + [1 2 3])
03:58	kungi	felipedvorak: then you don't need the 0
03:58	felipedvorak	wow, apply is new to me!
03:58	kungi	,(apply + [1 2 3])
03:58	clojurebot	6
03:59	felipedvorak	the 0?
03:59	kungi	felipedvorak: (reduce + _0_ list)
03:59	felipedvorak	alright!
04:00	justin_smith	kungi: you don't need the 0 anyway
04:00	justin_smith	,(reduce + [1 2 3])
04:00	clojurebot	6
04:00	felipedvorak	justin_smith: Yeah, this is something I just realized, I'm always using reduce with an entry value when its not needed
04:01	justin_smith	felipedvorak: well, better to supply a non-needed initial value than not provide one when needed
04:01	kungi	I just found my first real world usage of `tree-seq`
04:03	felipedvorak	kungi: the overall code, you would call this usable in the real world? the structure? sorry, I'm new to programming AND to functional, so I'm a bit (lot) confused hehe
04:04	kungi	felipedvorak: I would extract the (if (or (mod ... into its own predicate function `mod-3-5?`
04:04	felipedvorak	hmm
04:05	felipedvorak	very nice
04:05	kungi	felipedvorak: And I would use a precondition in add-all-odd to check for the vector instead of using a comment
04:05	felipedvorak	I still don't know how to do that :)
04:05	kungi	felipedvorak: And btw. It does not expect a vector.
04:06	felipedvorak	vector? perhaps hehe
04:06	felipedvorak	kungi: I see, I'm removing this malformed mental constructo about vectors from my mind immediately.
04:06	kungi	felipedvorak: let me write it and show you my solution
04:07	felipedvorak	great
04:08	kungi	felipedvorak: solution is 233168?
04:08	felipedvorak	yeah
04:08	felipedvorak	hehehe
04:09	kungi	(defn mod-3-5? [x] (or (= (mod x 3) 0)
04:09	kungi	(= (mod x 5) 0)))
04:09	kungi	(apply + (filter mod-3-5? (range 1000)))
04:09	felipedvorak	ok
04:10	felipedvorak	hehe still a lot to learn :)
04:10	justin_smith	kungi: use (zero? (mod x y))
04:10	kungi	justin_smith: yes
04:10	kungi	stull a lot to learn :)
04:11	justin_smith	that's why we are all here, even me believe it or not
04:12	felipedvorak	thanks both of you! :) 5am, my clojure addiction must come to an end for today
04:13	kungi	felipedvorak: good night :-)
04:24	expez	(defn bar [baz] (foo!)), should bar really be bar!?
04:25	kungi	expez: What are you trying to communicate? -:)
04:25	expez	kungi: is the bang naming convention transitive?
04:26	kungi	expez: in my opinion yes it is
04:26	expez	Or rather, I often see in the wild that it is not, but should it be?
04:26	kungi	expez: Hmm no wait .... it depends
04:27	kungi	expez: If you properly hide your impurity in a function then ! may not be transitive
04:27	clojurebot	excusez-moi
04:28	justin_smith	kungi: except in clojure.core ! often means not safe in a transaction, and unless you do some intense defensive programming that will be transitive
04:28	justin_smith	eg. because it combines retries and side effects
04:38	justin_smith	(doc io!)
04:39	clojurebot	"([& body]); If an io! block occurs in a transaction, throws an IllegalStateException, else runs body in an implicit do. If the first expression in body is a literal string, will use that as the exception message."
04:55	amalloy	i don't think transitive is the right word for that
04:55	amalloy	contagious would be my choice
04:58	justin_smith	"the flu is a transitive property of humans"
05:03	amalloy	yes indeed, for any three humans a, b, c, if a flu b and b flu c, then a flu c
05:04	amalloy	today's achievements: make flu into a verb
05:04	justin_smith	heh
05:04	sobel	nomenclature question: if a function has a remote side-effect (e.g. sftp cwd) should it end in !
05:05	sobel	or is that more aimed at namespaced vars
05:05	justin_smith	sobel: I'd say it's safe to skip if it's idempotent, but usually yes it should
05:05	sobel	hmmm. i like that.
05:05	justin_smith	sobel: my rule of thumb is "what if someone used the function inside a swap! call and it was done 50 times in a row"
05:05	justin_smith	would that suck? if so, use !, if it wouldn't matter, no
05:06	sobel	seems sensible enough.
05:06	justin_smith	sobel: not that I always follow this advice (handler code is especially egregious here in my codebases)
05:06	sobel	it's side-effect grey area
05:07	justin_smith	the kind of bug that's been haunting us lately is double transmits on a websocket in a react app
05:07	justin_smith	like - sometimes the server gets two requests and it should have gotten one
05:08	justin_smith	not all our request handlers listening on the websocket are idempotent, so we get weird ass bugs (many coming from weirdness in react it seems (probably because misusing react))
05:08	justin_smith	I would just debounce server side, but that only handles the symptom (and increases latency)
05:08	sobel	i hear that
05:10	justin_smith	it appears one bug was being caused by a side-effecting button that was acting like an innocent link, so that a pop-up preview caused a double-trigger of the event (maybe)
05:10	justin_smith	or, I should say "css magic tried to make an innocent link be a side effecting button"
05:11	amalloy	debounce? is that a common term?
05:11	sobel	yes
05:12	justin_smith	amalloy: it is a way to turn sputtering event clusters into a single event, comes from analog electronics, where a switch will literally bounce
05:12	amalloy	i feel like i've heard it in a past life, and can infer meaning from context, but have no real idea how i would have learned it
05:12	justin_smith	rebound
05:12	sobel	yes, it is literally slew-rate limiting
05:12	amalloy	slew-rate! it's like i have suddenly forgotten how to understand english
05:13	justin_smith	it's also closely related to how things like double-click are possible (if not technically used)
05:13	justin_smith	second event during bounce period = this is a double click
05:14	justin_smith	(also check for confounding parameters like x/y motion that would counterindicate, of course)
05:15	sobel	so idempotent handlers would prevent the 'bouncing' in the first place
05:15	justin_smith	right, but some of our handlers create resources for the client, this isn't negotiable
05:15	justin_smith	also, some idempotent actions are CPU expensive, so triggering twice is bad
05:16	sobel	so, can't that still be faux-idempotent (create-or-ignore)
05:16	justin_smith	I was also tempted to invent a higher order function that would return "your function, but refuses to run a second time". I could even abuse memoize for this if I was feeling dirty. But this also only fixes the symptom.
05:16	sobel	yeah, i wasn't quite clear how memoize wouldn't work
05:16	TEttinger	runonce to parallel defonce, justin_smith?
05:17	TEttinger	both rhyming with Beyonce
05:17	justin_smith	sobel: they are allowed to create two resources with the same parameters, it's a time-dependent thing - it's just that if the amount of time is under 5 seconds they won't get an interesting result
05:17	justin_smith	TEttinger: haha, awesome idea
05:19	justin_smith	(defn runoncé [f] ...)
05:19	sobel	(inc justin_smith)
05:19	sobel	,(inc justin_smith)
05:19	clojurebot	#error {\n :cause "Unable to resolve symbol: justin_smith in this context"\n :via\n [{:type clojure.lang.Compiler$CompilerException\n :message "java.lang.RuntimeException: Unable to resolve symbol: justin_smith in this context, compiling:(NO_SOURCE_PATH:0:0)"\n :at [clojure.lang.Compiler analyze "Compiler.java" 6704]}\n {:type java.lang.RuntimeException\n :message "Unable to resolve symbol:...
05:20	sobel	ok
05:20	justin_smith	sobel: the first one was right, but lazybot is on vacation I guess
05:20	sobel	clearly
05:21	sobel	i like the fn, defoncé
05:24	sobel	(def Brawndo™ [] (basically-mtn-dew) )
05:24	sobel	yes, unicode makes programming fun
05:26	sobel	🐙
05:44	TEttinger	sobel: unicode is fun
05:44	TEttinger	,(def def "Pfft, can't take the value of a macro, eh?")
05:44	clojurebot	#'sandbox/def
05:45	TEttinger	,def
05:45	clojurebot	"Pfft, can't take the value of a macro, eh?"
05:45	justin_smith	,(macro? def)
05:45	clojurebot	#error {\n :cause "Unable to resolve symbol: macro? in this context"\n :via\n [{:type clojure.lang.Compiler$CompilerException\n :message "java.lang.RuntimeException: Unable to resolve symbol: macro? in this context, compiling:(NO_SOURCE_PATH:0:0)"\n :at [clojure.lang.Compiler analyze "Compiler.java" 6704]}\n {:type java.lang.RuntimeException\n :message "Unable to resolve symbol: macro? in t...
05:45	justin_smith	,(:macro (meta #'def))
05:45	clojurebot	#error {\n :cause "Unable to resolve var: def in this context"\n :via\n [{:type clojure.lang.Compiler$CompilerException\n :message "java.lang.RuntimeException: Unable to resolve var: def in this context, compiling:(NO_SOURCE_PATH:0:0)"\n :at [clojure.lang.Compiler analyzeSeq "Compiler.java" 6891]}\n {:type java.lang.RuntimeException\n :message "Unable to resolve var: def in this context"\n ...
05:45	TEttinger	fine special form
05:45	justin_smith	haha
05:46	TEttinger	,(map def '(a b c) [1 2 3])
05:46	clojurebot	#error {\n :cause "Unable to resolve symbol: def in this context"\n :via\n [{:type clojure.lang.Compiler$CompilerException\n :message "java.lang.RuntimeException: Unable to resolve symbol: def in this context, compiling:(NO_SOURCE_PATH:0:0)"\n :at [clojure.lang.Compiler analyze "Compiler.java" 6704]}\n {:type java.lang.RuntimeException\n :message "Unable to resolve symbol: def in this conte...
06:25	noncom\|2	i am thinking about hosting a webserver written in clojure with the frontend written in clojurescript somewhere. the service is a CRM-like thing, i am wondering, what minimal and what recommended machine specs are?
06:25	noncom\|2	in particular, how much RAM do I need for that?
06:25	noncom\|2	no huge load is planned, just some document office work
06:33	wink	noncom\|2: I've successfully hosted a soup clone in pure clojure on a 5$ digitalocean box (incl. postgres)
06:34	wink	noncom\|2: sooo... I wouldn't go lower :) but should be enough for a first shot
06:34	noncom\|2	very nice!
06:35	wink	I think it will depend on your concurrent users as well
06:35	noncom\|2	well, for the moment there'll be no more than 100 users with occasional access to forms and documents, so should be ok. 512 or 1024 ram will do then
06:35	noncom\|2	btw what is soup? :_
06:36	noncom\|2	:)
06:36	wink	soup.io - a microblog with some social functions
06:36	wink	mostly posting pictures
06:36	noncom\|2	ah, i see
06:38	noncom\|2	cool!
06:39	noncom\|2	wink: btw, have you used hoplon?
06:39	wink	never even heard that
06:39	noncom\|2	i'm just picking the framework for now
06:40	noncom\|2	i worked with luminus, and there's also hoplon..
06:40	noncom\|2	so will try hoplon too then
06:41	wink	I've also mostly used luminus
06:41	wink	and somethin before that...
06:42	wink	noir
06:42	noncom\|2	yeah, noir is deprecated now. luminus builds on the best remaining parts of noir, compojure and stuff
06:42	noncom\|2	hoplon is more innovative, but idk is it all good or bad or just different
06:43	noncom\|2	for now it looks very cool, but different
06:43	noncom\|2	sometimes it is hard to choose between two techologies esp if you see no clear difference between them unless you've made a big project to feel it all through
06:49	wink	hehe
06:49	wink	sounds like our rewrite from ember to angular
06:50	wink	I'm only playing around with clojure web apps, nothing serious
06:50	wink	so far luminus was fine
06:50	noncom\|2	yeah, me the same :D
06:50	wink	and unlike with noir (when it got deprecated) I don't see a good reason to change anything even if it might be a lot better
06:51	wink	that said, the time will come when I am nosy enough to try my 30th web framework
06:51	wink	still havent used a rust one for example :)
06:52	noncom\|2	i did not use any rust even at all yet
06:52	noncom\|2	tried go though, liked it, but i have no real tasks for that
06:52	noncom\|2	besides, getting off a lisp is hard.. :/
06:52	wink	yeah I needed a small windows gui for ffmpeg
06:53	wink	that's where I had my problem to solve
06:53	noncom\|2	haha, i worked with ffmpeg through java-cv, so i was able to do it in clojure :D
06:53	noncom\|2	java-cv is cool
06:54	noncom\|2	thanks for the info! gotta go now, cheers! :)
06:54	wink	bye
07:45	crocket	hi
07:45	crocket	Is there an alternative to datomic?
07:48	ianhedoesit	https://github.com/tonsky/datascript
07:53	muhuk	it's in-memory only AFAIK.
07:56	msw	Is there a quick (clj) repl command to check in which protocol(s) a given method (say .. toString) is (potentially) defined?
07:57	Bronsa	msw: toString is not a protocol method
07:58	Bronsa	msw: for actual protocol methods, (:protocol (meta #'proto-method))
07:58	crocket	datascript is not an alternative to datomic.
07:59	ianhedoesit	that's the closest I'm aware of
08:01	msw	I see, thanks Bronsa.
08:09	Bronsa	woah datascript now supports clojure too, neat
08:25	crocket	What makes datomic special?
08:27	muhuk	crocket: special in what way?
08:27	crocket	I don't know
10:05	blucas	%n
10:23	tmtwd	how do I empty a whole channel in core async?
11:50	justin_smith	tmtwd: keep reading until you can't read any more in a loop?
11:52	mungojelly	is that really the idiom? i too was wondering if i should say like take-all or something
11:54	mungojelly	btw i'm running that ants.clj from rich's talk "clojure for java developers" or w/e that's one of the most popular talks on clojure, this is an awesome toy, someone should have linked me to this when i asked, this looks fun
12:08	expez	1.7 is such a breaking change it's not even funny
12:08	expez	Even library author now rewriting their libraries to use reader conditionals effectively forcing all consumers to also run 1.7 if they want patches
12:08	expez	Every*
12:10	Bronsa	expez: 1.7 is a breaking change?
12:10	expez	Is there any reason at all to ship cljc files to the consumer over two platform specific files?
12:10	expez	Bronsa: effectively yeah
12:11	Bronsa	expez: every release has had additional features over the previous ones, what's special about 1.7?
12:12	expez	Bronsa: I suppose the previous releases were nice to haves, but a lot of people seem to think cljc is essential.
12:13	expez	I get the allure of only maintaining a single file, but that should be an implementation detail and I'd prefer if people still shipped clj and cljs files :/
12:14	Bronsa	cljc is essential if you want to use reader conditionals
12:15	expez	obviously?
12:16	expez	You don't have to write your library with reader conditionals, though. And if you do I'd prefer if you processed those files as part of deployment and also shipped platform specific files so I don't have to upgrade to 1.7 to receive patches!
12:16	justin_smith	expez: why can't you use 1.7?
12:17	expez	justin_smith: I can, but I don't want to force everyone using CIDER and clj-refactor to use 1.7 :/
12:17	Bronsa	expez: oh come on, having to maintain both a clj and a cljs version of a library is so much worse than using reader conditionals
12:18	expez	Bronsa: Sure, but you can process those files and put the clj and cljs files in the jar along with the cljc file...
12:19	Bronsa	expez: that's what people did with cljx before clojure had native support for reader conditionals
12:20	expez	Guess I'm done here if nobody sees a problem
12:20	expez	Just needed to vent
12:20	Bronsa	expez: why can't cider/clj-refactor just process the cljc files internally to strip the reader conditionals?
12:21	kavkaz	How come the REPL is not letting me do (map Integer/parseInt <some-seq>) but it lets me do (map #(Integer/parseInt %) <some-seq>)
12:21	kavkaz	?
12:21	justin_smith	kavkaz: methods are not first class
12:23	kavkaz	justin_smith: So it's not a function object?
12:23	kavkaz	like (fn []), (defn [] ...) or #()
12:23	justin_smith	no, Integer/parseInt is a static method
12:24	justin_smith	another way to put it is that functions are objects, Integer/parseInt is not an object
12:24	kavkaz	justin_smith: Oh i see
12:24	kavkaz	Now that I think about it from a Java perspective
12:27	justin_smith	kavkaz: and since a static method is not itself a class, it isn't actually a thing that you can place on a call stack - in order to do so, clojure would have to implicitly create the anonymous function version for you
12:28	justin_smith	not itself an object - sorry
13:43	Narfinger	hiho, i am just starting out to learn clojure and i wonder if there is a similar library for xml parsing as hxt for haskell
13:43	Narfinger	for anybody who does not know, you basically define your structure of elements and it does the reading and writing according to the structure
13:53	justin_smith	Narfinger: we don't actually need something that strict, since we don't have Haskell's type system
13:53	justin_smith	Narfinger: not to say it doesn't exist - it might, but there is less motivation
14:06	justin_smith	Narfinger: if your data source is actual XML, clojure.data.xml might work (though it does have its limitations related to namespaces iirc)
14:14	noncom\|2	justin_smith: once you said "i prefer websockets where available" - so, where are they not yet available?
14:14	Narfinger	ok i will look around thanks
14:17	justin_smith	noncom\|2: some http servers / some clients, depends on what you are required to deploy to / support
14:18	justin_smith	noncom\|2: though sente has a nice feature where it works with a post based fallback if websockets are not supported client side
14:19	noncom\|2	but all general browsers do have support... i just wander, what a client today would not support it.. but i think i'm not gonna get in this situation...
14:19	justin_smith	noncom\|2: http://caniuse.com/#feat=websockets
14:20	justin_smith	so unless you need to support android 4.3 or ie 9, you are probably good?
14:21	noncom\|2	justin_smith: wow, that was exactly what i was looking for!
14:21	noncom\|2	thanks!
14:33	mungojelly	-> and ->> are fun but also they seem random, it seems like semantics is given sometimes to the positions to try to unrandomify it with partial success, i thought of maybe something that threads through maps by key or something so it could be more explicitly semantic
14:34	noncom\|2	mungojelly: they are not random in any degree
14:34	noncom\|2	mungojelly: what is your original task?
14:34	noncom\|2	mungojelly: maybe you're looking for get-in?
14:34	mungojelly	noncom\|2: hm? i'm just learning clojure. what i mean is that you're threading through the first/last argument, which gives those positions special powers
14:35	justin_smith	mungojelly: you can use ->> inside ->
14:35	justin_smith	and if you need a position that isn't first or last, you can use as-> inside ->
14:35	mungojelly	which is almost like having a semantics, and then there's things like um, the sequences it said somewhere are all sequence last, so then that approaches semantic order to it so you can thread through the last which happens to be a sequence, yay
14:35	mungojelly	oh cool i don't know as-> yet what's that?
14:35	oddcully	,(doc as->)
14:35	justin_smith	,(-> 1 inc (-> as n (* n n)))
14:35	clojurebot	"([expr name & forms]); Binds name to expr, evaluates the first form in the lexical context of that binding, then binds name to that result, repeating for each successive form, returning the result of the last form."
14:35	clojurebot	#error {\n :cause "Unable to resolve symbol: n in this context"\n :via\n [{:type clojure.lang.Compiler$CompilerException\n :message "java.lang.RuntimeException: Unable to resolve symbol: n in this context, compiling:(NO_SOURCE_PATH:0:0)"\n :at [clojure.lang.Compiler analyze "Compiler.java" 6704]}\n {:type java.lang.RuntimeException\n :message "Unable to resolve symbol: n in this context"\n ...
14:36	justin_smith	,(-> 1 inc (as-> n (* n n)))
14:36	clojurebot	4
14:36	justin_smith	,(-> 1 inc (as-> n (* n n) (inc n)))
14:36	clojurebot	5
14:37	mungojelly	so -> threads at the beginning, ->> at the end, and as-> in the middle, it's beautiful, i'm not saying it's not beautiful
14:37	mungojelly	but also you're like manually building something, i'd rather they were more like magic magnetic connectors and you wave them at one another and they fall in line good
14:37	noncom\|2	mungojelly: correction: -> threads at the second place
14:38	noncom\|2	mungojelly: well, these are core macros and are intended to be very simple
14:38	oddcully	as-> with the varname/position as you like (not only once, not only in the middle)
14:38	noncom\|2	mungojelly: also, take a look at the swiss arrows clojure library :)
14:39	noncom\|2	mungojelly: the core functions/macros must not have magic. they all have very simple meanings. magic can be created in libraries
14:40	mungojelly	ha well this is all very magic to most programmers still but i do think i see what you mean
14:40	noncom\|2	mungojelly: also, in most cases it is sufficient to use just -> or ->> or, rarely, their combination, as justin points out
14:41	mungojelly	are you saying you don't like my idea :p
14:41	noncom\|2	mungojelly: if you find yourself in need of more, it can be a sign that you need a (let) form with clearly labeled subresults
14:41	noncom\|2	mungojelly: nono, it's not that i don't like the idea
14:41	mungojelly	i want to thread semantically too, if the things i'm threading through have arguments with semantic names and i can say "thread through the :foo arguments" then i can take a random collection of stuff and throw it together more carelessly
14:43	mungojelly	or like you could take the same chains and thread them through various ways, like what are the chances a chain that works with -> is also going to work with ->> because it's haphazard but if they had semantically marked arguments they could easily happen to work with multiple ones
14:43	mungojelly	maybe i'm just talking about monads again idk
14:44	noncom\|2	mungojelly: yes, this looks like modals, and you could have such functionality here, but really, it is far from basic
14:44	noncom\|2	mungojelly: it is not always clear for the compiler, what do you really want to do and when it should signal you an error
14:45	noncom\|2	mungojelly: with that much guessing it can quickly break things
14:45	noncom\|2	since lisp is very fluid
14:45	noncom\|2	mungojelly: here's what - why don't you try to write such a macros youself?
14:46	mungojelly	well because i just learned clojure's macros yesterday, i suppose. i made a few simple things and it went fine as soon as i got used to all this # business. ;)
14:47	noncom\|2	mungojelly: actually, in the end you may come up with a pretty useful library, that's serious and a good excercise
14:47	noncom\|2	congrats with learning the stuff :)
14:48	mungojelly	here's something i'm thinking of writing, i want an abstraction that's a grid of tiles, like the tiles each know how to draw themselves and there's a display context that asks the tiles in its field of view to draw themselves, etc
14:48	mungojelly	is there something like that already, a generic tiles interface?
14:50	mungojelly	it seems to me like that would be a friendly context for beginners to start making things in, because they just need to make a few tiles that know how to be tiles, and then ideally there'd be various pretty viewers and tools that they're compatible with
14:50	noncom\|2	mungojelly: never heard of such a thing. how are you going to draw them, what graphics api to use? or you mean just data rendering of an n-dimensional grid?
14:50	mungojelly	there's a zillion games written with tiling systems but none of the ones i've read yet have the tiles written as a separate abstraction :(
14:51	mungojelly	noncom\|2: weeeeeeeeell i could target a particular graphics api, or i could target some intermediate abstraction, what do you think would be useful??
14:51	mungojelly	like they could just say a list of polygons to paint on their tile, and then various viewers could translate that into various graphics apis
14:51	noncom\|2	mungojelly: ah, i see. yep, you could very well do that. i would ofcourse decouple data rendering from the drawing api. and for the draving api in your particular case i'd pick the quil library that bases over processing
14:52	mungojelly	i saw something about quil and it looked awesome but i haven't tried it yet
14:53	mungojelly	one way i think would make sense to do it is to have tiles that know how to draw themselves in a zillion different ways, like they can make a tiny little version of themselves for zoomed out views, and say how to paint themselves as ascii, etc
14:54	noncom\|2	quil is a very simple, friendly and powerful tool that will let you do things reaaaally quick without boring stuff. then, when you have your engine functional, you can plug in other renderers
14:54	mungojelly	then if you make a tile set that implements all the different ways of viewing it you can view the same game made with those tiles through all those lenses
14:54	noncom\|2	mungojelly: interesting
14:57	noncom\|2	mungojelly: with that idea you could create tiles described by a certain dsl with symbols that draw themselved in various ways
14:58	mungojelly	i'd think of implementing that like tiles are a map with :ascii goes to a function that paints the ascii, etc., so like {:ascii paint-ascii :polygons paint-polygons} is that clojurey
14:58	noncom\|2	you mean ascii and polygons are two different renderers?
14:58	noncom\|2	well, it's not about clojure i think, its about the concept more
14:59	noncom\|2	i think more clojuric and functional would be to have a single language (a DSL) to describe a tile and then have interpreters of that DSL for every renderer
15:00	mungojelly	i was wondering earlier in general, is that what you do in clojure is fill data structures with functions you want to use, i thought of putting fields in my things and tucking functions into them but maybe i'm just messily recreating some object system i should use?
15:01	noncom\|2	mungojelly: hm, you could have functions stored in datastructs if you need that. but i am not sure about your specific cases. when i started clojure i was constantly finding myself recreating OOP
15:01	noncom\|2	after a period it gone, OOP and clojure (FP that it is) got separated completely, not i can use them independetly
15:02	noncom\|2	s/not/now
15:02	mungojelly	well i mean the dsl is that there's tiles with attributes, so not much to it, {:name "I'm a happy tile!" :tiny-ascii "**\n!\n**\n"} etc, but then i think of tucking code(-like data) into them somewhere to make them pop
15:02	noncom\|2	mungojelly: having fns in datastructs is perfectly fine if you really need this
15:03	noncom\|2	mungojelly: if you're asking about having a function stored within it to render it like ((:renderer tile) (:data tile)) then that's recreating OOP :)
15:04	noncom\|2	is this what you mean?
15:04	justin_smith	yeah, you don't need to recreate OOP in clojure, we've got protocols/records/multimethods for this
15:04	justin_smith	actual OOP!
15:05	noncom\|2	yeah, and even going futher than justin is saying, i almost never use protocols/records/multimethods in my programs :D so i went even that far
15:05	mungojelly	i read that there's something called protocols, but i haven't understood yet how they go
15:06	noncom\|2	not that it is a good example, many people use them, but that's just how it can possibly be too
15:06	mungojelly	so many facts about clojure are stirring my head and making it feel soupy
15:06	justin_smith	mungojelly: in pure clojure, the only way to have a method is to implement a method is to implement some protocol defining that method
15:06	mungojelly	clojure does seem to cohere though, there's some sense to it, the words are all somewhat memorable (a blessed rarity among lisps)
15:07	noncom\|2	mungojelly: yeap, clojure is that type of soup that is used to make crystals
15:07	justin_smith	oh wow that was a mess
15:07	justin_smith	the only way to implement a method is to implement some protocol defining that method
15:08	mungojelly	it just turns into actual normal java method dispatch right? so i get to copy my intuitions from there. that's part of what makes this language so learnable.
15:08	mungojelly	it's so hard to tell because of course every language is easier to learn than the last but it really does feel like a very easy language to learn.
15:08	justin_smith	mungojelly: pretty much, aside the fact that we don't really do concrete inheretence (only interfaces)
15:09	mungojelly	it's an odd thing in computer science, that inheritance didn't turn out to be very useful. in theory it seemed like it was going to be useful. hm.
15:11	noncom\|2	nah, inheritance is a very artificail concept, that's why it did not work
15:11	noncom\|2	does not go well hand-in-hand with the rest of the type theory
15:11	noncom\|2	well, it works, but in a much more limited application that many anticipated
15:12	mungojelly	clojure though scares me it's so much the other way, by which i mean nothing has any defined structure at all you're just biting at keywords in things :/
15:13	justin_smith	mungojelly: it's possible to have more structure - via things like defrecord, even deftype, protocols, prismatic/schema and core.typed
15:13	justin_smith	it's all optional though
15:13	noncom\|2	well, it's just a lisp with unstrict typing
15:13	noncom\|2	yeah and what justin says
15:14	noncom\|2	there are ways to impose total control of your structures
15:14	noncom\|2	turns out you don't need them most of the time though
15:14	noncom\|2	but sometimes yeah
15:14	mungojelly	yeah of course it's possible, but i mean just in general as a habit it seems to be the code here just works with bare data structures and secretly understands the semantics of them
15:14	noncom\|2	because in lisp there's actually not much semantics :)
15:15	mungojelly	of COURSE my thingamabob has a doohickey as its third whatzit, what else would it have
15:15	noncom\|2	:)
15:17	noncom\|2	my story was this: i wanted to learn a lisp for a very long time, but did not understand. then i became java, then, as a soft OOP->FP transition i was scala... was storming lisp walls several times never getting a grasp. i simply could not understand. then at one moment i understood that there's nothing to understand. it's just simple and it works.. was a revelation of sorts
15:18	mungojelly	i still don't understand common lisp, the concepts are fine but put them all together with that WEIRD VOCAB and i can't follow a thing. but i learned scheme from SICP, which is fantastic.
15:20	noncom\|2	hmmm maybe :D
15:21	noncom\|2	but there's just lambda and variable names..
15:25	noncom\|2	mungojelly: so, if you're going to explore the tiling system or write the intellectual threading macro, cool! if you have some progress later, we're glad to witness and try it out :)
15:26	noncom\|2	as i am programming games myself, i am especially excited about the tiling system excersise..
15:26	mungojelly	what are you up to? any code up i can read? i need to read a bunch of clojure
15:28	mungojelly	ugh if my tiles want to move should they request to move from a board manager or what sigh
15:29	mungojelly	i definitely feel like i'm not thinking clojure-y enough
15:29	justin_smith	IMHO unless you have a strong reason to do things otherwise, a tile should be pure data, and you should have a function that takes a board of tiles and returns a new board of tiles (including any moves needed)
15:30	noncom\|2	mungojelly: well, actually lately i am using a game engine (JMonkeyEngine 3) to create software for audio-visual installations, mappings and stuff... unfortunately it is protected by my employers contract but i can share the wrapper for JME3, if you later come to it
15:30	justin_smith	so the board is a big container, tiles are smaller containers inside it, and the logic is in a function that transforms boards by moving tiles
15:31	noncom\|2	mungojelly: yes, you have data and separately - functions that manipulate it
15:31	mungojelly	justin_smith: yes that's sorta what i was thinking but then.. do i ask every tile every time if they want to move? :/
15:31	noncom\|2	mungojelly: but i also be happy to answer any game programming related questions you might have regarding clojure specific stuff... and other people here too do games
15:32	noncom\|2	mungojelly: you just update the whole board at once
15:32	noncom\|2	mungojelly: like push the board through the monad
15:32	mungojelly	well what i don't know is what you already have. do you have anything? is there anything i can play with? i mean like little abstractions, toys
15:32	justin_smith	mungojelly: it depends on what your ruleset is? if it's like chess, the "player" abstraction should decide what should move, if it's like conway's life, you should process one group of 9 at a time, each time determining the fate of the one in the middle...
15:33	mungojelly	justin_smith: i'm just making a general abstraction for building various toys and games and experiments on. maybe serious things too i suppose w/e.
15:34	mungojelly	it's like a toybox that comes with some generic empty boards and some sets of tiles and then you can build from there
15:34	mungojelly	take the alphabet tiles, make a word game
15:34	justin_smith	mungojelly: well, in that case you'll probably need to support both those models (plus others)
15:34	noncom\|2	mungojelly: eh, sorry, no real functional code to play with :/ all is protected by the contract :/
15:37	justin_smith	mungojelly: one cool design which is very popular in the game world, and fixes a lot of the problems introduced by OO in games, is ECS
15:37	justin_smith	entity component systems
15:38	mungojelly	the whole time i've been learning to program i've been reading programs for games with tiles in them hoping for something i can pick up and play with but it's always, for row, for col, row * width * hope you got the rotation right, draw the imperative sequence of things :(
15:38	justin_smith	it's like you took the object graph, and made a normalized database out of it - you have a list of ids representing all entities in the game, and each property is actually a table mapping from an id to a value
15:38	mungojelly	justin_smith: everyone's saying ECS over and over but i don't understand what the big deal is. they weren't doing that already? wtf?
15:39	justin_smith	mungojelly: the difference is with ecs the player doesn't have a color
15:39	justin_smith	the game has a table of colors, that maps the player id to a color
15:39	justin_smith	so it's not OO at all in the layout
15:39	justin_smith	closer to sql
15:40	mungojelly	..which they weren't already doing? every basic programming text tells you not to hardcode numbers. do we not understand that colors are numbers and you can't do that with colors either. hardcoded numbers everywhere.
15:40	justin_smith	mungojelly: the point is, there is no player object
15:40	justin_smith	and before ecs they were doing OO, where your entities are objects
15:41	mungojelly	i've been so irritated the whole time i've been learning by the lack of anything for me to play with and it's my theory there's no good reason for it at all, which i now will have to back up with some code, but i don't see what the problem is, i really don't, just give beginners any toys at all. :(
15:42	mungojelly	i want to give them some boards, like maybe finite boards and infinite boards, and then some tiles to put on the board
15:42	justin_smith	then do that
15:42	justin_smith	the problem with easy tools for beginners is that too often big systems are built with those tools, as if you had a temple made of tinker toys. What works in the small isn't the same as what works in the large.
15:43	mungojelly	and then there's an example game and what it says is, give me some tiles and arrange them like this, so then of course you can make a different program that arranges them differently, or different tiles to plug in
15:43	mungojelly	yeah like these incredible movies people have been making in scratch, have you seen those?!
15:44	mungojelly	i checked it out because TIOBE said that Scratch is one of the top languages so i checked out what people are making with it lately. give people any tools they can use at all, even if it's difficult, and they'll do it. they'll do difficult as long as they can observe incremental progress.
15:44	tmtwd	http://pastebin.com/qrvqc90E what is the .. in this function? and the -target and -value?
15:44	justin_smith	sure, and my job would be a living hell if I had to make things in scratch
15:45	justin_smith	but it's a great tool for learning, and a great toy
15:45	justin_smith	(doc ..)
15:45	mungojelly	unlike those users, you'd quickly add new blocks
15:45	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."
15:45	noncom\|2	tmtwd: yes, one of the java interop things
15:46	justin_smith	tmtwd: .. is like -> but only for methods
15:46	tmtwd	oh
15:46	mungojelly	(doc ...)
15:46	clojurebot	Pardon?
15:46	mungojelly	just wondering
15:46	justin_smith	tmtwd: so -target is actually property access (.-target e)
15:46	tmtwd	oh I see
15:47	tmtwd	(.-target e) and (.-value )
15:47	tmtwd	right I get it
15:47	justin_smith	right, the whole form is actually (.-value (.-target e))
15:49	augustl	anyone else suddenly getting "error in process filter: Wrong number of arguments: (1 . 1), 0" in emacs for cider-jack-in?
15:49	justin_smith	mungojelly: I've done a lot of visual programming (mostly in puredata), and the biggest problem is that the number of relations between things that you can draw clearly is limited on a 2d surface, we can easily read text and infer a larger collection of relations with less ambiguity
15:49	justin_smith	augustl: sounds like you updated something in your cider ecosystem
15:50	augustl	I haven't touched it since I installed it but for some reason I have a -snapshot dependency
15:50	augustl	so perhaps it was updated automatically by leiningen
15:50	augustl	(in my ~/.lein/profiles.clj)
15:50	justin_smith	yup, snapshots are intended to update
15:50	justin_smith	but that's an elisp error
15:51	augustl	when I set this up a long time ago I had to use snapshots to make it work
15:51	augustl	doh, I did update all my packages in emacs too
15:52	justin_smith	augustl: in my experience when I update any packages that are in any way related to cider in emacs, I need to delete my elc files before things work again
15:52	mungojelly	justin_smith: one mistake i think all those systems make is they're ugly, or rather just boring looking. you're wiring up boxes, and they're all boxes. they need to be like candy cane striped and fluffy if they're this sort of thing, something that engages your visual perception of them.
15:52	justin_smith	augustl: emacs / cider should be smart enough to work this out itself, but somehow is not
15:52	noncom\|2	mungojelly: btw, maybe nightcode by zach oakes is getting close to what you're saying
15:52	mungojelly	even scratch is just about being cute and silly and yet the blocks are all pretty much the same except they're color coded. boooooooring.
15:52	augustl	justin_smith: will try that, tnx :)
15:53	mungojelly	noncom\|2: i tried to run it and it didn't work. :( nightcode, nightrun or something, i tried the one that makes games. but when i clicked to show the code it just showed a greyness. :(
15:54	noncom\|2	hmmm.. should not be like that
15:54	mungojelly	i thought i'd see if i was doing anything obvious wrong and then write to the author
15:55	noncom\|2	what could possibly be done wrong with a program that should work out-of-the-box?
15:56	augustl	hmm, deleting the elpa folder solved the problem. I'm this close to throwing out emacs.. Why do I have to waste time with mundane bugs in software that's at least a few centuries old
15:57	kavkaz	augustl: Personally I don't really have any alternative to emacs + CIDEr
15:58	kavkaz	CIDER*
15:58	kavkaz	I was using vim with the lein repl in a tmux session, but it wasn't the same
15:58	augustl	yeah, I'm addicted to its paredit too
15:58	justin_smith	~justin_misth
15:58	clojurebot	Gabh mo leithscéal?
15:58	justin_smith	~justin_smith
15:58	clojurebot	justin_smith is sits on a throne of lies
15:58	justin_smith	~justin_smith
15:58	clojurebot	justin_smith is sits on a throne of lies
15:58	justin_smith	ugh keeps getting the wrong factoid
15:58	kavkaz	of course there's the eclipse plugin counterclockwise, but It's really not the same, because I'm too hooked on the vim bindings
15:59	justin_smith	anyway, I gave up on cider, and now code by banging parens with rocks
15:59	justin_smith	kavkaz: cursive is probably the most extensive integration right now
15:59	kavkaz	justin_smith: you mean emacs version 1.0
15:59	kavkaz	?
15:59	justin_smith	kavkaz: I mean zero editor integration
15:59	kavkaz	they added pebbles and sticks in version 1.5
15:59	justin_smith	heh
16:00	augustl	all editors having "added paredit" in a relatively late changelog lose a lot of trust from me :P
16:01	kavkaz	justin_smith: do you use cursive?
16:01	justin_smith	kavkaz: I use emacs with no repl integration
16:01	kavkaz	justin_smith: Ah i see
16:01	justin_smith	kavkaz: I edit the code in emacs, save it, then reload it in my repl terminal
16:01	kavkaz	justin_smith: That's what I used to do with vim in tmux
16:01	kavkaz	but i need those rainbow parentheses lol
16:02	mungojelly	what is cursive, how do you extend it
16:02	oddcully	~cursive
16:02	clojurebot	Gabh mo leithscéal?
16:02	noncom\|2	its simply a clojure ide on top of jetbrains idea
16:02	mungojelly	i've gotten a vague impression that cursive is a cool thing so i have it on my list of things to try
16:02	augustl	kavkaz: I've found "highlight opposite parentheses" to be sufficient
16:03	noncom\|2	many ppl say cursive is cool!
16:03	noncom\|2	it is being actively developed
16:03	kavkaz	I'm gonna give it a shot with cursive, I have 240mb free space on my SSD lol
16:03	augustl	mungojelly: cursive is "oh god which editor do I hate the least whatever I'll throw money at the problem"
16:04	oddcully	i run vim-fireplace most of the time and check from time to time into cursive, what it complains about
16:06	kavkaz	Nah I'll stick with emacs
16:08	kavkaz	augustl: To me emacs just has been a better experience. But I understand the struggle of trying to get it to work the way you want it to
16:09	kavkaz	It's been said very well, vim is something that works right off the bat, emacs is something that you have to poke around with
16:12	augustl	emacs is my favorite so far as well
16:18	kavkaz	Honestly I think bbatsov's work on CIDER and Clojure mode makes emacs very sufficient for Clojure
16:21	kavkaz	Also all the other contributors for those projects, I know there's at least a couple here
16:21	kavkaz	and for other community projects as well
16:23	augustl	yeah that part is really nice, it's emacs itself I'm struggling with - it's so big!
16:25	Tagore	emacs can be kind of tricky- it kind of comes from a different time.
16:27	justin_smith	I don't know, I figured out emacs itself OK, but I'm too stupid to use cider properly
16:27	Tagore	It can also be very rewarding, especially if you want to do the kind of programming Slime and its alternatives allow.
16:31	Tagore	Hmm- well I just joined this channel, so I'm missing context.
16:31	Tagore	And I'm just starting to play with Cider- have used Slime a lot in the past though.
16:32	Tagore	What's up with Cider?
16:32	Tagore	And you?
16:33	kavkaz	Cider is honestly very minimal
16:33	justin_smith	Tagore: I used cider, it's features kind of worked, and every time any part of it was upgraded the whole thing would break
16:33	kavkaz	justin_smith: perhaps if you have an extensive emacs config as it is, many things will break
16:33	justin_smith	I got tired of fixing it all the time, and stopped using it. But clearly other people are productive with it.
16:33	kavkaz	when I started I only had evil mode on
16:34	justin_smith	kavkaz: being able to switch to evil mode was a bonus of leaving cider
16:34	kavkaz	augustl: check out braveclojure.com, he talks about emacs, I got a couple pointers from there
16:34	kavkaz	most of my proficiency with emacs comes from practice though... well, as with anything
16:35	kavkaz	justin_smith: Ah i see. I don't think evil mode broke too many bindings. Perhaps this is an earlier version of cider you're talking about?
16:35	kavkaz	Anyways I gotta go guys
16:35	augustl	I guess a core problem is my grumpyness.. I don't want to have to deal with weird errors after updating packages that are solved by basically a "clean' :)
16:35	justin_smith	kavkaz: versions 0.5 through 0.9, things broke all along the way
16:35	justin_smith	augustl: exactly
16:36	justin_smith	perhaps my fundamental problem was imagining a paradigm where packages could be updated
16:38	expez	Expecting software marked unstable to be stable isn't fair
16:39	expez	CIDER uses semver so you should expect some stuff to break until it reaches 1.0
16:39	justin_smith	OK
16:40	justin_smith	expez: I guess I got used to clojure world, where I can use core.async 0.00001-ALPHA-asdlkfjasdklfj and then upgrade to 0.00002-ALPHA-joiasdf and things don't break
16:40	augustl	the problem seemed to be with emacs and how it compiles packages though
16:40	expez	Some people are even using the Melpa build while complaining about it being unstable. Melpa is like the development snapshot so unless you're willing to jump into the debugger every now and then you should definitely use melpa-stable
16:41	augustl	or I guess at least you could say emacs makes it possible for cider to update in a way that is broken unless you do a "clean" of already compiled elisp
16:41	justin_smith	expez: I wasn't using melpa, but you've concinced me to try cider if there's ever a 1.0
16:41	expez	justin_smith: the package manager gets better in emacs 25, but now you often have to manually delete packages after upgrading because emacs kept some of the old stuff around :/
16:42	justin_smith	expez: I guess cider was the only emacs thing I ever used that saw breaking abi changes, so it looked like a cider problem rather than an emacs one. But yeah, that sounds like a problem with emacs.
16:44	justin_smith	expez: also the nature of the projects I'm working on mean I expose some hairy edges UX wise. I have four clojure processes running at a time, juggling them is much easier when none of them are in my editor
16:44	expez	justin_smith: CIDER is 16k lines of Elisp now, and 4k lines of clojure. I doubt many other packages you use are of similar complexity.
16:46	justin_smith	yeah, that's very likely true
16:46	expez	justin_smith: you should check in every now and then to help find nasty edge cases :)
16:46	mungojelly	expez: huh that is big, what all does it do?
16:46	Tagore	Justin: do you have a way of interacting with a running program right now that works for you, or are you restarting it every time you change the code?
16:46	justin_smith	Tagore: I use (require my.ns :reload)
16:46	justin_smith	it's simple and it works
16:47	expez	mungojelly: check out the readme here https://github.com/clojure-emacs/cider for a list stuff
16:47	justin_smith	oops, (require 'my.ns :reload) of course
16:49	mungojelly	am i prematurely optimizing by thinking of having my tiles say what kind of tile they are and referring to one copy of how to draw them etc., will clojure make it ok if i just put the same thing over and over for the same tile. oh i guess it won't make it ok in serialized forms or whatever. so i should definitely just have the board be indirectly pointing to the tiles.
16:50	srbaker	heya folks.
16:50	srbaker	i'm using enlive-html to do some scraping for my first clojure project.
16:50	mungojelly	i'm just going to have them indexed by a vector of [x y] i guess, indexing by vectors is pretty, or should i name them x and y like {x: 0, y: 0} hm
16:51	srbaker	first q: what's the easiest way to print out the value of a function so i can see what it's giving me? i think it's a map, but i'm not sure
16:51	srbaker	i currently have just a println
16:51	Tagore	I haven't used that approach, so I have no idea what it's like to program using it. I have always found it very nicve to be able toi interact with a running Lisp image from my editor.
16:52	srbaker	http://pastebin.com/J9Q7bsyk that's what println gives me. but i'm having a hard time mapping over it
16:52	srbaker	i don'tknow why
16:52	clojurebot	Cool story bro.
16:52	justin_smith	srbaker: there's prn if you want the output to be less ambiguous, or you could print the type of the thing
16:52	srbaker	aha, prn is what i wanted for now. thanks
16:53	justin_smith	srbaker: here's my trick (-> d type) followed by (-> d count) (-> d first type) (-> d first keys) (-> d first :attrs)...
16:53	justin_smith	srbaker: this is very quick if you are using the arrow keys in the repl, you can find your data quickly
16:53	justin_smith	srbaker: also, it helps to put a pprint at the end sometimes to get multi line printout
16:53	srbaker	okay i've updated the paste: http://pastebin.com/Rqrgv8D1
16:53	srbaker	what type is that? and where do i get a list of functions i can use with it?
16:53	srbaker	specifically, i want the string at the end.
16:54	justin_smith	it's a list which contains a number of things, including hash maps
16:54	justin_smith	srbaker: use the -> as I recommended above, you'll find a series of accessors that get the data you want
16:55	justin_smith	(where d is the var containing that whole big blob of data of course)
16:56	srbaker	i suppose i should probably set up emacs to be more helpful
16:57	justin_smith	srbaker: here's how to do it (I just used your paste as the starting data) you don't need emacs, this is just a regular repl https://www.refheap.com/109471
16:58	srbaker	nice. tanks
16:58	srbaker	thanks
16:58	justin_smith	just fixed the formatting
16:59	srbaker	weird. so what's working in the repl is not working in my code
16:59	srbaker	(defn vf-days [] (html/select (vf) [:p.p1]))
17:00	srbaker	when i try to do first type on that, it complains that it can't convert it too ISeq
17:00	srbaker	when when i prn it, and paste it into (def d on the repl, no problem
17:00	justin_smith	srbaker: OK, what does your code say the type is?
17:01	srbaker	LazySeq
17:01	srbaker	er
17:01	justin_smith	then you should be able to get the first item of that
17:01	srbaker	whoops. missing parens
17:01	srbaker	hah
17:02	srbaker	i'm sure i'm not the first dude to run into that :P
17:02	justin_smith	the learning process never ends
17:18	srbaker	is there a has-key function?
17:18	justin_smith	srbaker: contains?
17:18	srbaker	i want to know if a map has a key :tag
17:18	justin_smith	,(contains? {:tag "OK"} :tag)
17:18	clojurebot	true
17:18	srbaker	what's ,?
17:19	justin_smith	,(contains? {:bag "OK"} :tag)
17:19	clojurebot	false
17:19	srbaker	ah, thanks
17:19	justin_smith	srbaker: it makes clojurebot evaluate things
17:19	srbaker	nice.
17:20	justin_smith	srbaker: also, in normal clojure code , is whitespace
17:20	_Bruno_	hey guys, does anyone know why (into {} [[:a 1] [:b 2]]) => {:a 1, :b 2} while (into {} ['(:a 1) '(:b 2)]) => throws ClassCastException??
17:20	justin_smith	,,,,,(,,,,,+,,,,,,,,,,21,,,,,,,10,,,,,11,,,,),,,,,,,,,,,,,
17:20	clojurebot	42
17:20	justin_smith	_Bruno_: because lists cannot be coerced to map-entries, but vectors can
17:21	_Bruno_	I came across this by trying to manipulating a sequence and turn it into a map, and I was curious to understand why the vector version works but it breaks with lists or sequences.
17:21	srbaker	(defn new-day [item] (if (contains? (item :content) :tag)) ...
17:21	srbaker	i'm getting "unable to resolve item in this context" which is confusing :(
17:21	justin_smith	srbaker: too many parens
17:21	justin_smith	for starters...
17:22	justin_smith	or wait...
17:22	justin_smith	srbaker: are you sure that's what you have? because that should not complain about item - I mean if item is not callable it would complain about that
17:22	justin_smith	(:content item) would be more canonical
17:22	_Bruno_	justin_smith: is there any particular reason why would you not coerce a list into a map entry?
17:23	justin_smith	_Bruno_: I'm not totally certain of the reasoning, but I do know that clojure can use a vector as a map entry without creating a new data structure
17:23	justin_smith	or something like this...
17:23	justin_smith	but this can't be done with a list
17:24	_Bruno_	I guess the protocol need to be extended to lists as well.
17:25	justin_smith	well, lists aren't associative
17:25	justin_smith	so I don't know if extending the protocol even makes sense in that case
17:25	_Bruno_	MapEntry isn't either, it need just a tuple of two values
17:26	srbaker	it is complianing about item
17:26	justin_smith	_Bruno_: yes it is, all vectors are associative, and mapentry is a vector
17:26	justin_smith	,(associative? [])
17:26	clojurebot	true
17:27	srbaker	it is definitely complaining about item :(
17:28	justin_smith	srbaker: can you use refheap.com to show us the whole function?
17:28	_Bruno_	justin_smith: vectors are but here you are trying to bridge Java's MapEntry which only cares about a key and a value which in turn can be extracted from a list with `first` and `second`
17:28	justin_smith	_Bruno_: no, this is clojure's map entry, which is a two element vector
17:28	luma	clojure's mapentry is a vector
17:29	justin_smith	_Bruno_: this isn't about the java data structures in hash maps at all
17:29	_Bruno_	justin_smith: it's java's one ClassCastException clojure.lang.Keyword cannot be cast to java.util.Map$Entry
17:30	justin_smith	,(into {} ['(:a :b)])
17:30	clojurebot	#error {\n :cause "clojure.lang.Keyword cannot be cast to java.util.Map$Entry"\n :via\n [{:type java.lang.ClassCastException\n :message "clojure.lang.Keyword cannot be cast to java.util.Map$Entry"\n :at [clojure.lang.ATransientMap conj "ATransientMap.java" 44]}]\n :trace\n [[clojure.lang.ATransientMap conj "ATransientMap.java" 44]\n [clojure.lang.ATransientMap conj "ATransientMap.java" 17]\n ...
17:30	justin_smith	oh, right, sorry
17:30	srbaker	hrm. not getting that error now. must've had some parens missing
17:30	justin_smith	anyway, the Map$Entry is a vector of two elements, regardless of provenance
17:30	srbaker	or too many at the bottom
17:31	_Bruno_	justin_smith: thx, i'll dig in the source code
17:31	justin_smith	_Bruno_: it's very unlikely you'll convice the core clojure team to change conj such that it would convert lists to map entries
17:32	justin_smith	though I guess it could be done hypothetically as a local extension
17:32	luma	clojure map's cons tries three different things: it checks if the object is a java.util.Map$Entry, then checks if it's a clojure.lang.MapEntry, then treats it as a sequence of java.util.Map$Entry without checking
17:32	justin_smith	luma: oh! I feel much less stupid now, thanks
17:32	justin_smith	luma: and it's conj not cons, of course
17:33	luma	in the java source, it's cons (but in clojure, conj obviously)
17:33	luma	https://github.com/clojure/clojure/blob/master/src/jvm/clojure/lang/APersistentMap.java
17:33	justin_smith	oh, cool
17:33	srbaker	so the canonical form is (key map) for getting values from maps?
17:34	justin_smith	srbaker: if the map is not a literal but the key is, yes
17:34	srbaker	okay
17:34	justin_smith	srbaker: the idea being that you know what the key is because it's literal
17:34	justin_smith	whereas what happens if the map were a list instead? or nil?
17:43	luma	reading my comment again, the second check is actually for vector and not MapEntry
17:43	luma	so that's why vector works but a list doesn't
17:45	_Bruno_	luma: looking at the code it looks like that lists or sequences are not accepted in order to be able to distinguish between the two following cases: (conj {} [:a 1] [:b 2]) and (conj {} {:a 1 :b 2})
17:45	luma	sounds reasonable
17:45	_Bruno_	the first one is a variadic parameter as seq of vectors
17:45	luma	since seqing a map results in a sequence of mapentries
17:45	_Bruno_	the second one is a seq of map.entry
17:46	justin_smith	I keep forgetting that (conj {} {}) works
17:52	srbaker	is there a pretty print function that will make these maps a bit easier to read when i print them?
17:52	justin_smith	clojure.pprint/pprint
17:52	srbaker	tack
17:52	justin_smith	it's automatically imported into your starting ns as pprint if you use nrepl
18:14	srbaker	,(seq? "")
18:14	clojurebot	false
18:15	justin_smith	,(map seq? [nil [] {} ()])
18:15	clojurebot	(false false false true)
18:36	srbaker	okay, this is a super weird error
18:37	srbaker	https://www.refheap.com/109472
18:37	srbaker	i'm sure it's someting to do with my expectionat of how the if works
18:37	srbaker	in new-day
18:37	justin_smith	srbaker: line 10, (true)
18:37	justin_smith	,(true)
18:37	clojurebot	#error {\n :cause "java.lang.Boolean cannot be cast to clojure.lang.IFn"\n :via\n [{:type java.lang.ClassCastException\n :message "java.lang.Boolean cannot be cast to clojure.lang.IFn"\n :at [sandbox$eval25 invokeStatic "NO_SOURCE_FILE" 0]}]\n :trace\n [[sandbox$eval25 invokeStatic "NO_SOURCE_FILE" 0]\n [sandbox$eval25 invoke "NO_SOURCE_FILE" -1]\n [clojure.lang.Compiler eval "Compiler.java"...
18:37	TEttinger	,true
18:37	clojurebot	true
18:37	justin_smith	srbaker: parens in clojure are not for grouping
18:38	justin_smith	they are for calling things
18:38	srbaker	oh
18:38	srbaker	right, of course
18:38	srbaker	and that shouldbe false :P
18:38	srbaker	excellent. thanks
18:39	justin_smith	also, line 100 (= (:tag (first item))) will always return true
18:39	justin_smith	,(= (:tag nil))
18:39	clojurebot	true
18:39	justin_smith	err, I mean line 11
18:39	srbaker	oh, right, i'm missing :strong
18:41	justin_smith	,(map #(apply (first %) %&) (iterate #(conj % =) [= =]))
18:41	clojurebot	#<ArityException clojure.lang.ArityException: Wrong number of args (0) passed to: core/=>
18:42	srbaker	i'm getting a lot furhter when i switched to test-driving this.
18:42	justin_smith	srbaker: yeah, that can help a lot when it comes to keeping your steps organized
18:42	justin_smith	(and ensuring you don't break something as you fix something else)
18:42	srbaker	especially since i've practised TDD pretty much without exception since about 2001
18:44	justin_smith	,(map #(apply (first %) (rest %)) (iterate #(conj % =) [= =]))
18:44	clojurebot	(true true true true true ...)
18:44	justin_smith	srbaker: that would help too!
18:45	justin_smith	srbaker: I'm a big fan of how you can make tests easy to implement in clojure by separating logic from side effects
18:45	justin_smith	well, I mean you can do that in other languages too, but clojure has some nice facilities for this sort of thing
18:46	amalloy	feature request: since (apply f x [y z]) is the same as (apply f [x y z]) already, (apply [f x y z]) should work too
18:47	giantwaffelcat	why do people think clojure is a lisp
18:47	dbasch	giantwaffelcat: because it plays one on the internet
18:47	amalloy	FR #2: replace all other characters in clojure source code with ( and )
18:47	justin_smith	giantwaffelcat: because they disagree with you about the definition of the word lisp
18:48	giantwaffelcat	heh
18:48	giantwaffelcat	I'm just upset Clojure lacks cons
18:48	TEttinger	,cons
18:48	clojurebot	#object[clojure.core$cons__4090 0x6db6d0a6 "clojure.core$cons__4090@6db6d0a6"]
18:48	justin_smith	,(cons 'a nil)
18:48	clojurebot	(a)
18:48	giantwaffelcat	justin_smith: not proper cons
18:48	TEttinger	do you mean cons pairs?
18:48	giantwaffelcat	,(cons 'a 'b)
18:48	clojurebot	#error {\n :cause "Don't know how to create ISeq from: clojure.lang.Symbol"\n :via\n [{:type java.lang.IllegalArgumentException\n :message "Don't know how to create ISeq from: clojure.lang.Symbol"\n :at [clojure.lang.RT seqFrom "RT.java" 535]}]\n :trace\n [[clojure.lang.RT seqFrom "RT.java" 535]\n [clojure.lang.RT seq "RT.java" 516]\n [clojure.lang.RT cons "RT.java" 655]\n [clojure.core$con...
18:48	giantwaffelcat	TEttinger: yes.
18:49	TEttinger	,['a 'b]
18:49	clojurebot	[a b]
18:49	dbasch	giantwaffelcat: don’t focus on the cons, think of the pros
18:49	TEttinger	it is not that much different.
18:49	giantwaffelcat	also the fact nil isn't the (canon?) empty list is annoying
18:49	amalloy	anything you can do with improper lists you can do with real lists anyway
18:49	giantwaffelcat	dbasch: ...goddamnit
18:50	TEttinger	,(seq (range 0))
18:50	clojurebot	nil
18:50	TEttinger	,(seq [])
18:50	clojurebot	nil
18:51	TEttinger	if empty list was equivalent to nil, would appending to it result in a list or a vector?
18:51	TEttinger	conj can produce either
18:51	srbaker	aw shit, partition-by won't do what i want anyhow :(
18:51	TEttinger	,(conj nil 1)
18:52	clojurebot	(1)
18:52	TEttinger	appears to be a seq anyway
18:52	srbaker	i was hoping that given a list of 1, 2, 1, 2, 1, 2; i could partitionon (= 1 1) and get three lists. whoops!
18:53	TEttinger	,(partition-by (partial not= 1) [1, 2, 1, 2, 1, 2])
18:53	clojurebot	((1) (2) (1) (2) (1) ...)
18:53	TEttinger	,(partition-by (partial = 1) [1, 2, 1, 2, 1, 2])
18:53	clojurebot	((1) (2) (1) (2) (1) ...)
18:53	TEttinger	ah!
18:53	TEttinger	you may want group-by, not sure
18:53	srbaker	oh
18:53	justin_smith	TEttinger: group-by returns a hash-map
18:53	TEttinger	err, no...
18:54	TEttinger	yeah I realized it was wrong after I said it
18:54	TEttinger	still waking up
18:54	srbaker	i basically want to iterate the list, and start a new sub-list every time (new-day) is true
18:54	justin_smith	srbaker: sounds like a good time to use reduce
18:55	srbaker	yeah.
18:56	justin_smith	,(apply conj (reduce (fn [[done curr] el] (if (even? el) [(conj done curr) [el]] [done (conj curr el)])) [[][]] [1 2 1 1 2 1 1 1 2 1 1 1 1 2])
18:56	clojurebot	#<RuntimeException java.lang.RuntimeException: EOF while reading>
18:56	justin_smith	,(apply conj (reduce (fn [[done curr] el] (if (even? el) [(conj done curr) [el]] [done (conj curr el)])) [[][]] [1 2 1 1 2 1 1 1 2 1 1 1 1 2]))
18:56	clojurebot	[[1] [2 1 1] [2 1 1 1] [2 1 1 1 1] [2]]
18:56	TEttinger	(inc justin_smith)
18:56	justin_smith	every instance of an even number starts a new vector
18:56	TEttinger	lazyboooooot!
18:56	justin_smith	KHAAAAAAAN
18:57	srbaker	,(apply conj (reduce (fn [[done curr] el] (if (odd? el) [(conj
18:57	srbaker	done curr) [el]] [done (conj curr el)])) [[][]] [1 2 1 1 2 1 1
18:57	srbaker	1 2 1 1 1 1 2]))
18:57	clojurebot	#<RuntimeException java.lang.RuntimeException: EOF while reading>
18:57	srbaker	whoops
18:57	justin_smith	srbaker: yeah, one liners only with lazybot
18:57	srbaker	,(apply conj (reduce (fn [[done curr] el] (if (even? el) [(conj done curr) [el]] [done (conj curr el)])) [[][]] [1 2 1 1 2 1 1 1 2 1 1 1 1 2]))
18:57	clojurebot	[[1] [2 1 1] [2 1 1 1] [2 1 1 1 1] [2]]
18:57	TEttinger	,(apply conj (reduce (fn [[done curr] el] (if (odd? el) [(conj done curr) [el]] [done (conj curr el)])) [[][]] [1 2 1 1 2 1 1 1 2 1 1 1 1 2]))
18:57	clojurebot	[[] [1 2] [1] [1 2] [1] ...]
18:57	srbaker	i'm actually oversimplifying with 1 and 2
18:58	justin_smith	srbaker: I assumed, but I also figure you can do the mutatis mutandis to make it work with your code
18:58	srbaker	it's literally: a list of lists. the list is either a 1 element string; or a list of things where the first element is a hash with :tag => :strong
18:58	srbaker	and it comes in, in order.
18:58	justin_smith	srbaker: do they always strictly alternate?
18:58	srbaker	i'm writing a bot to scrape and parse the lunch menus for the two restaurants near our office
18:58	srbaker	so we can ask a slack bot what's for lunch.
18:59	justin_smith	srbaker: admirable plan
18:59	srbaker	justin_smith: yes, they always alternate. but the list elements mightbe varied
18:59	srbaker	here's the menu: http://valfarden.nu/dagens-lunch/
18:59	justin_smith	in that case you can ditch the reduce and use partition-all 2
18:59	justin_smith	,(partition-all 2 [:a :b :a :b :a :b :a :b])
18:59	srbaker	nope. while there are two options per day this week
18:59	clojurebot	((:a :b) (:a :b) (:a :b) (:a :b))
18:59	srbaker	it's not always true
19:00	justin_smith	ahh, OK
19:00	srbaker	ii think reduce will do it
19:00	justin_smith	in that case a reduce to start new collections as you go should handle it then
19:00	justin_smith	yeah
19:00	srbaker	yep. it's a pattern i'm not familiar iwth, and it's 1am
19:00	srbaker	so i'm probably going to give up for the night shortly
19:01	srbaker	the solution is reduce, so i can start with that in the morning
19:01	srbaker	i know how i'd do this with #inject in ruby, which is just reduce.
19:01	justin_smith	srbaker: do note that this is using a non-obvious idiom of making a collection of collections as the accumulator, and conditionally emptying an in-progress collection into the master collection at each step
19:02	justin_smith	s/emptying/putting oops
19:06	justin_smith	I should totally write a splits function that does what people keep expecting split-with to do
19:09	amalloy	flatland.seq has partition-between
19:09	amalloy	er, flatland.useful.seq
19:10	_Bruno_	justin_smith: what do you think split-with should do?
19:12	justin_smith	_Bruno_: I'm fine with what split-with does, but what people keep expecting it to do is slice a collection based on a predicate
19:12	justin_smith	so that each item that is truthy for that predicate becomes the start of the next subsequence
19:12	justin_smith	(which is also useful and I think deserves to be its own function)
19:12	_Bruno_	justin_smith: isn't that partition-by ?
19:13	justin_smith	I think that's a special case of amalloy 's partition-between
19:13	justin_smith	_Bruno_: partition-by only splits once
19:13	justin_smith	oh wait,
19:13	justin_smith	you are right
19:13	amalloy	justin_smith: no, he's not
19:13	justin_smith	_Bruno_: it's almost partition by
19:14	_Bruno_	the one which split only once is split-at
19:14	justin_smith	but still not quite - that one starts a new coll every time the f returns a different value
19:14	amalloy	your predicate thing is different from partition-by, but not because of number of splits
19:14	amalloy	right
19:15	justin_smith	what I am talking about is (splits #{:a} [:a :b :a :b :c :a :c]) => ((:a :b) (:a :b :c) (:a :c)))
19:16	amalloy	right. which is different fro partition-by
19:16	justin_smith	amalloy: yeah, and it can be done with partition-between just by testing the pred on the second item in the arg
19:17	_Bruno_	justin_smith: could be called split-when
19:17	justin_smith	_Bruno_: that's a good name for it
19:18	amalloy	the split- family of functions each split once, and the partition family split N times. if you were going to define this function i wouldn't call it split-X
19:18	_Bruno_	amalloy: partition-when then :-)
19:20	oddcully	partition-at
19:22	justin_smith	,(defn partition-when ([p? [c & cs]] (partition-when p? cs [c])) ([p? [c & cs] acc] (cond (empty? cs) [acc] (p? c) (lazy-seq (cons acc (partition-when p? cs [c]))) :else (partition-when p? cs (conj acc c)))))
19:22	clojurebot	#'sandbox/partition-when
19:22	justin_smith	,(partition-when #{1} [1 2 1 2 3 1 2 3 4 1 2 1])
19:22	clojurebot	([1 2] [1 2 3] [1 2 3 4] [1 2])
19:23	justin_smith	oh it dropped the last part there...
19:23	oddcully	then do a partition-when-all
19:24	_Bruno_	(defn partition-when [p c] (->> c (partition-by p) (partition-all 2) (map (partial apply concat))))
19:24	justin_smith	,(defn partition-when ([p? [c & cs]] (partition-when p? cs [c])) ([p? [c & cs :as coll] acc] (cond (empty? coll) [acc] (p? c) (lazy-seq (cons acc (partition-when p? cs [c]))) :else (partition-when p? cs (conj acc c)))))
19:24	clojurebot	#'sandbox/partition-when
19:24	justin_smith	oddcully: it was just a bug, I don't need the all version :P
19:25	justin_smith	,(partition-when #{1} [1 2 1 2 3 1 2 3 4 1 2 1])
19:25	clojurebot	([1 2] [1 2 3] [1 2 3 4] [1 2] [1])
19:25	justin_smith	_Bruno_: that's a nice way to do it too
19:28	noncom\|2	i am using the latest version of tower and timbre from ptaoussanis and tower cannot be required because it does not find "timbre/logp", how can this be?
19:28	noncom\|2	both are of the latest versions and from the same author
19:28	noncom\|2	did anybody encounter such an issue?
19:30	justin_smith	noncom\|2: have you checked lein deps :tree ? that should show potential conflicts or misversionings
19:31	amalloy	justin_smith: the lazy-seq is in an odd place there. i think you want to either write (lazy-seq (cond ...)) or, better, (cons acc (lazy-seq ...)). and the last clause can/should use recur
19:31	justin_smith	ahh
19:31	justin_smith	good point, thanks
19:31	justin_smith	*points
19:31	noncom\|2	nope, did not check, will look at it now
19:37	noncom\|2	justin_smith: heh, it does not show anything, but manually i have found out that the latest version of tower uses timbre 3.3.1 while the latest version of timbre is 4.1.1
19:37	noncom\|2	weird
19:39	noncom\|2	damn so i hate when projects do not compile of incompatible logging frameworks...
19:39	noncom\|2	had this happening in java many times
19:39	noncom\|2	thats why i really prefer println
19:40	justin_smith	noncom\|2: I know, let's make a new logging framework api, that should fix this problem right?
19:40	noncom\|2	yeah!
19:40	noncom\|2	:D
19:41	emdashcomma	heh
19:41	crocket	What makes datomic attractive?
19:41	emdashcomma	strong, symmetrical features
19:41	crocket	Its EULA is unattractive, though.
19:43	oddcully	haha. and while you are at it also create a new linux distribution
19:45	noncom\|2	sure! we'll get it integrated right into the core!
19:45	oddcully	a linux distro specialized in java logging
19:46	noncom\|2	yeah!
19:46	noncom\|2	and it will be very flexible, so the user will have to like, manually compile like 1000+ other libs
19:46	emdashcomma	infinitely configurable
19:46	crocket	Fuck
19:46	emdashcomma	make sure it doesn't do anything useful out of the box
19:46	emdashcomma	better, have a team of consultants to offer
19:47	noncom\|2	yeah! and we'll provide a script that does half of the setup for ubuntu 10.04 coz we care
19:47	oddcully	export EDITOR=nano sorted!
21:53	elvis4526	Is there a way to pass arguments to tests ?
21:53	elvis4526	Let's say for example when you're inside a fixture
21:53	justin_smith	no, fixtures don't pass data to tests
21:53	justin_smith	though they can use binding of special vars
21:54	justin_smith	elvis4526: but remember that you can call test/is inside a normal function, and then call that function from multiple tests
21:54	justin_smith	(or multiple times in one test)
21:54	justin_smith	and then, you absolutely can pass in eg. different test data to the same harness
21:55	Trioxin	what do ppl use for clojure on windows? intellij?
21:56	Trioxin	cursive..
21:57	cfleming	Trioxin: People use all sorts of things, but I try to make it easy with Cursive
21:57	cfleming	Installing lein can be tricky so I bundle it, and you can do all your leiny things from the IDE
21:58	cfleming	Which is useful for getting started - you'll want it working on the command line at some point though
21:58	elvis4526	justin_smith: okay thanks. Special vars are the same thing as normal vars, right?
21:58	Trioxin	cursive seems to not be out yet
21:58	justin_smith	elvis4526: not quite
21:58	justin_smith	,(def foo 1) ; elvis4526 note the warning
21:58	clojurebot	#error {\n :cause "denied"\n :via\n [{:type clojure.lang.Compiler$CompilerException\n :message "java.lang.SecurityException: denied, compiling:(NO_SOURCE_PATH:0:0)"\n :at [clojure.lang.Compiler analyzeSeq "Compiler.java" 6891]}\n {:type java.lang.SecurityException\n :message "denied"\n :at [clojurebot.sandbox$enable_security_manager$fn__835 invoke "sandbox.clj" 69]}]\n :trace\n [[clojureb...
21:58	cfleming	Trioxin: It's not officially released but it works fine, it's as stable as anything else I think
21:59	justin_smith	elvis4526: anyway, in a real repl, if you try (def foo 1) it will warn you that the var is not declared dynamic, even though it has earmuffs
22:00	justin_smith	elvis4526: you make a special var with (def ^:dynamic foo)
22:00	elvis4526	Ah, right. I just tried with a non-special vars in the fixture and its still working
22:00	justin_smith	oh, you can use def too
22:01	justin_smith	but with a dynamic var you can use (binding [foo ...] ...) to rebind
22:02	elvis4526	the stackoverflow answer I read made it sound like the stars were just there to let know the programmer that the var was not dependant on lexical scope
22:02	justin_smith	the convention is that dynamic vars have ear-muffs
22:03	justin_smith	and yes, dynamic vars don't use lexical scope
22:03	elvis4526	okay - and what's exactly the difference between let and binding ?
22:04	Trioxin	Cursive > La Clojure?
22:04	Trioxin	both are intellij plugins
22:04	elvis4526	Trioxin: La Clojure is not maintained anymore AFAIk
22:04	Trioxin	kth
22:04	Trioxin	x
22:04	crocket	℘
22:04	justin_smith	elvis4526: let binds values to symbols that must be explicitly passed into a form to be used by that form
22:04	oddcully	i'd forget about ≠ cursive
22:05	oddcully	it's all old
22:05	justin_smith	elvis4526: binding changes the value of a dynamic var, and this has effect until another binding form is reached, or the scope of the binding call is escaped
22:05	justin_smith	and this does not rely on passing values in, it changes the execution environments view of some var
22:06	justin_smith	the reason we make dynamic vars look weird is because the scope and value rules for binding can lead to programs that are hard to reason about
22:07	justin_smith	(but calling def inside runtime forms instead is even worse, mind you)
22:09	elvis4526	okay i get it - thanks
22:09	elvis4526	i'm not sure where dynamic vars would be that useful though
22:10	justin_smith	for situations where you need to change some code's execution environment. It's very useful for the UI of emacs, so much so that the default is for variables to have dynamic binding.
22:10	amalloy	they're easier to misuse than use correctly
22:10	justin_smith	very true
22:11	amalloy	the compiler and other tooling like emacs make use of a fair number of dynamic vars, but most user programs won't
22:11	justin_smith	elvis4526: another example, out is a dynamic var, because a repl user should be able to change where a subprogram sends its output without adding an extra arg to every output function
22:12	elvis4526	yeah it make sense - cool
22:20	Trioxin	so, I want to write my first clojure program (first lisp for that matter) and i have cursive and it's asking me what project type so I guess I should start with Java EE Application??
22:21	justin_smith	Trioxin: there should be a "lein project" option, or something like that
22:21	Trioxin	i dont see that
22:22	amalloy	you don't want a java application or a java ee application
22:22	Trioxin	http://screencast.com/t/xMMZ4ZVwffW
22:23	oddcully	Trioxin: for reasons unknow, it shows java ee... do a `lein new lerl` and open that project
22:23	crocket	Stay away from java ee
22:24	crocket	java ee involves application servers which you don't want to deal with.
22:24	justin_smith	Trioxin: that was the UI for "additional libraries and frameworks" and you don't need any of them - just a basic leiningen project
22:24	Trioxin	leiningen isn't under the clojure tab
22:24	crocket	Embed jetty in your web application. Don't embed your web application in a java-ee application server.
22:25	justin_smith	Trioxin: there's an option on the left to use Leiningen as the build / dependency manager
22:26	oddcully	Trioxin: do the `lein new` dance and then open/import from idea
22:26	Trioxin	so don't use the clojure tab to use clojure.. ok
22:26	justin_smith	cfleming: I think your further assistence might be required here
22:26	justin_smith	oddcully: he doesn't know lein yet I don't think, he was trying to do this via cursive (which I guess should be easier on windows?)
22:27	oddcully	justin_smith: then he has to learn. idea is just a borken editor
22:28	Trioxin	i've used other versions of this but not for java, for html5, php, C, C++, D
22:28	Trioxin	i mean not for lisp
22:30	Trioxin	choosing clojure as my first lisp
22:31	oddcully	Trioxin: i hate to bust the bubble, but idea is not the ``be all end all'' ide; cursive might lack right now the means to generate a project out of thin air. it's the same for "advanced" gradle, ...
22:32	Trioxin	guess I'll just find a clojure tutorial first and then i'll know how to do it all right
22:33	Trioxin	else I'll never cause the singularity
22:33	Trioxin	loljk
22:34	Trioxin	or am i?
22:34	cfleming	Trioxin: La Clojure is now officially deprecated in favour of Cursive
22:34	oddcully	no you are
22:34	oddcully	all of them is depricated by not beeing useable
22:35	Trioxin	im not using la clojure
22:35	Trioxin	and i've done a lot of machine learning code
22:35	cfleming	Trioxin: In that screencast you sent, "Leiningen" appears on the left hand side as one of the project creation options.
22:35	Trioxin	yes
22:36	cfleming	That's the one you want
22:36	cfleming	That will allow you to create a new lein project
22:36	oddcully	cfleming: not for me it doesn't
22:36	oddcully	stuck at some java ee nonsense
22:37	cfleming	oddcully: What are you doing, exactly? File->New->Project..., select Leiningen from the left hand side list?
22:37	Trioxin	hold on updating my jdk first and then going back in there
22:37	Trioxin	cfleming, new project, then that yes
22:38	oddcully	meta-i -> ``Create New Project'' -> ``Leinigen''
22:38	Trioxin	well, I was under "Clojure"
22:38	Trioxin	and I checked out the other as well not knowing what it was then looked it up and about to open it again
22:39	Trioxin	idea
22:39	cfleming	oddcully: What do you have meta-i bound to?
22:39	oddcully	cfleming: start intellij
22:39	cfleming	Ok
22:39	oddcully	cfleming: that little window, with the "pick your project" stuff
22:40	cfleming	oddcully: So you select "Leiningen", and the next step is Project SDK and Additional Libraries and Frameworks
22:41	Trioxin	oh he's doing the same thing I am
22:41	oddcully	cfleming: yes. it's project sdk (1.8 here) and then it provides only java ee BS
22:41	cfleming	Right.
22:41	oddcully	this is on linux, if you mind
22:41	Trioxin	same on windows
22:41	cfleming	Where are you seeing the Java EE stuff?
22:41	cfleming	Under "Additional Libraries and Frameworks"?
22:41	Trioxin	hold on ill screencast it again and try the leiningen
22:42	oddcully	cfleming: configure your idea to start up where the projects get picked
22:42	cfleming	oddcully: I don't understand what you mean
22:42	oddcully	iirc there is some switch that prevents loading the last project
22:42	cfleming	Oh, right
22:42	cfleming	Ok
22:42	cfleming	One sec
22:43	Trioxin	in my case there is no last project
22:43	oddcully	cfleming: isn't it way to early in the morning in jolly good england?
22:43	cfleming	Ok, let's go though this together
22:43	cfleming	oddcully: It would be, but I'm in jolly good New Zealand
22:43	Trioxin	ok lol
22:44	oddcully	in that case... i'm way to early in the morning...
22:44	oddcully	once you are at that
22:44	cfleming	Ok, so I'm on the "Welcome to IntelliJ" screen, previous project list on the left, IntelliJ logo on the right
22:44	oddcully	"idea startup screen thingy"
22:44	cfleming	Create New Project
22:44	oddcully	pick ``create new project''
22:44	cfleming	Leiningen
22:45	cfleming	Choose your SDK
22:45	oddcully	for me there is regardless what i pick ``java ee''
22:45	cfleming	oddcully: Can you send a screenshot of what you're seeing?
22:45	oddcully	e.g. if i pick gradle, there is gradle stuff...
22:45	oddcully	for leinigen there is only revolting java ee stuff
22:46	cfleming	oddcully: I need a screenshot to know what you're seeing
22:46	Trioxin	here's what he's doing
22:46	Trioxin	http://screencast.com/t/nEzBL05ONJ
22:46	cfleming	Trioxin: Thanks
22:47	Trioxin	;)
22:47	cfleming	Ok, so that's all under additional libs and frameworks, you don't want any of that
22:47	cfleming	It's all unselected by default
22:48	oddcully	well without a flash player i can not confirm it...
22:48	cfleming	Just press next after doing the SDK
22:48	cfleming	You should see Project name: Project location: Template: Template options:
22:49	Trioxin	yes
22:49	cfleming	So if you just want a basic project, give it a name and location and press Finish
22:49	cfleming	If you want to use a lein template, enter its name and any args it needs
22:51	Trioxin	eh. i used an uppercase char
22:51	Trioxin	there's an iml file
22:52	cfleming	The iml file is the IntelliJ module file
22:53	cfleming	You don't care about that
22:53	cfleming	Your namespaces will be under the src and test directories
22:53	Trioxin	oh wait
22:53	Trioxin	i did it without the uppercase erorr. now much more files
22:54	Trioxin	a project.clj file
22:54	Trioxin	src
22:54	Trioxin	core.clj
22:54	justin_smith	oh, yeah, it probably would not like a capitalized name
22:55	Trioxin	oh I have a hello world app
22:55	oddcully	cfleming: i can confirm, that clicking ``next'' and ignoring the java ee ends up in a clojure prohect
22:55	Trioxin	and my own namespace
22:55	cfleming	Nice
22:55	oddcully	s/h/j/
22:55	Trioxin	aaaaaand
22:55	Trioxin	some code I've never tried to understand sooo
22:55	Trioxin	lol
22:56	oddcully	from what is generated this looks like a `lein new xxx`
22:56	cfleming	Trioxin: Right click on the project.clj file in the root, and select Run REPL for <whatever>
22:56	cfleming	oddcully: That's exactly what it is
22:57	oddcully	shall i dare to use e.g. `figwheel` for the template?
22:57	cfleming	Fortune favours the brave
22:57	justin_smith	haha
22:57	Trioxin	the result of that didn't run my code
22:57	Trioxin	it ran some server
22:57	Trioxin	then gave me the clojure version
22:57	cfleming	Trioxin: And gave you a window on the right?
22:58	Trioxin	yeah
22:58	oddcully	works fine too...
22:58	cfleming	Trioxin: That's what you want. Now you're ready for a Clojure 101 tutorial.
22:59	Trioxin	oh but my binary or jar or whatever... something was just compiled right?
22:59	justin_smith	Trioxin: clojure has a repl
22:59	oddcully	cfleming: get lost of that java ee stuff... it's scary sh**
22:59	justin_smith	Trioxin: the repl compiles forms as you enter them
23:00	Trioxin	i was expecting hello world
23:00	justin_smith	Trioxin: the idea is that you can use the repl to interactively define things, and then use the things that work to build up your app
23:00	cfleming	oddcully: I can't do anything about that, if you never use J2EE just uninstall the J2EE plugins and you won't see that.
23:00	justin_smith	Trioxin: you can run your -main to get the hello world
23:00	oddcully	cfleming: and while you are here... can we assume, that "current-2 years" will be the target for cursive for idea?
23:00	justin_smith	Trioxin: but that's not what the repl does right away
23:01	cfleming	oddcully: Yeah, last two major versions. Currently I sort-of support 12.1 but that's going away soon. 13.1 support will go away when 15 becomes GA
23:01	Trioxin	i get what you're saying but how do I run the existing code?
23:01	justin_smith	Trioxin: what namespace is your repl in (you can tell from the prompt)
23:01	justin_smith	if it's in your core namespace, you can run (-main)
23:01	cfleming	justin_smith: Trioxin: actually in the title of the REPL tab
23:01	cfleming	In Cursive
23:01	justin_smith	cfleming: oh, OK :)
23:01	oddcully	cfleming: cool. i'd rather buy cursive than 15
23:02	cfleming	Trioxin: click in your main editor window
23:02	cfleming	Trioxin: Then Tools->REPL->Load File in REPL
23:02	Trioxin	im in core. i just ran core and it exited with code 0 and showed that in bottom console
23:02	Trioxin	oh k
23:03	cfleming	That will load your code into the REPL
23:03	Trioxin	it's loaded
23:03	cfleming	Then Tools->REPL->Switch NS to current file
23:03	cfleming	You should see the REPL NS change to the NS of your file
23:04	Trioxin	yes
23:04	cfleming	blah.blah.core, probably
23:04	cfleming	Ok, now you have your code from your editor loaded, and your REPL is in the same NS.
23:04	cfleming	Go to the REPL editor at the bottom right, and type (my-function), or whatever your function is called - I don't recall what lein generates off the top of my head
23:05	Trioxin	foo
23:05	cfleming	Ok, (foo) then
23:05	Trioxin	i did but it didn't do anything
23:05	cfleming	Sorry guys, I have to go
23:05	Trioxin	i just typed it
23:06	Trioxin	it autocompleted
23:06	cfleming	Hit Cmd-Enter
23:06	cfleming	Or Ctrl-Enter if you're on Win/Linux
23:07	oddcully	(inc cfleming)
23:07	oddcully	lazy bumbot
23:07	cfleming	You should also be able to type (+ 1 2) and hit Cmd/Ctrl-Enter and see 3 come out.
23:07	cfleming	Aww man, my fake internet points!!!
23:08	ro50	Hi everyone I'm a linux noob...when I tried to install leiningen the install 'worked' but I could only run lein in sudo mode
23:08	justin_smith	cfleming: I'll make sure you get them eventually
23:08	amalloy	ro50: you used apt-get?
23:08	justin_smith	ro50: it's better to just install lein to your ~/bin/ and not do a system wide install
23:08	ro50	I tried from the web site, apt get doesnt have version 2.x
23:08	amalloy	well that's good
23:08	cfleming	Ok, I really do have to go. Trioxin: assuming you can execute things there, check out Aphyr's Clojure from the ground up, or Clojure for the Brave and True, and just ignore the bit where it tells you to install Emacs :)
23:09	justin_smith	ro50: that's the right way, lein manages it's own version better than linux would do it for you
23:09	Trioxin	k thanks
23:09	oddcully	apt-get lein? that would get you lein 0.01?!
23:09	ro50	in ~/bin/ the ~ refers to the 'home ' folder?
23:09	justin_smith	ro50: right, and make sure that is on your path too of course
23:09	oddcully	ro50: yes, ~ is $HOME
23:10	justin_smith	the idea is to have it be executable, but belonging to your user only
23:10	ro50	ok ~ is home of my normal account is / is root of the entire os right
23:10	justin_smith	ro50: right
23:10	ro50	my home folder doesnt have a /bin so i make one
23:10	justin_smith	yup
23:11	justin_smith	ro50: many linux distros come with a shell set up to add ~/bin/ to your PATH at startup if it exists
23:11	justin_smith	but this is easy to fix if yours does not
23:11	justin_smith	s/startup/initial login/
23:12	Trioxin	Hello World!
23:13	Trioxin	finally
23:13	ro50	ok I installed it but it says lein is not currently installed
23:13	Trioxin	don't know why a hello world needs an argument but okay
23:13	ro50	when I type lein in the terminal
23:13	Trioxin	oic it concatenated
23:13	Trioxin	sweeeeeeet
23:14	justin_smith	ro50: is your ~/bin in the $PATH variable in the shell?
23:14	ro50	uh im not sure
23:14	oddcully	ro50: in a _new_ terminal try `which lein`
23:14	ro50	nothing happens
23:15	ro50	after typing $PATH I get: me@me ~ $ $PATH bash: /usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/usr/lib/jvm/java-8-oracle/bin:/usr/lib/jvm/java-8-oracle/db/bin:/usr/lib/jvm/java-8-oracle/jre/bin: No such file or directory
23:15	justin_smith	also double check that ~/bin/lein is executable, and then check that ~/bin/ is on your path (you can use echo $PATH to do that)
23:15	justin_smith	ro50: oh, you can also get your PATH from an error message :)
23:15	justin_smith	so no, ~/bin/ is not on your path, and you need to add it
23:15	justin_smith	in your shell you can do PATH=$PATH:~/bin/
23:16	justin_smith	to make this happen automatically it can be added to your shell init file, usually .bashrc or .login or .profile or something
23:16	justin_smith	(all will be hidden files in your home directory)
23:18	ro50	oh there is already something in there for that
23:18	ro50	i will try reset and see if it works
23:18	ro50	brb
23:19	justin_smith	oh man he left before I could tell him about "bash -l"
23:19	oddcully	he'l be right back
23:20	justin_smith	oddcully: right, but he didn't need to reboot
23:20	justin_smith	or whatever he thought he had to do
23:20	oddcully	he is doing the ole windowsaroo: reboot to update the env
23:20	justin_smith	the ms-dance
23:21	Trioxin	so, I'm used to curly braces and this defn shows the closing ) on the same line as the last statement in it. Is it bad form to close the function on the next line?
23:22	justin_smith	Trioxin: yup
23:22	Trioxin	whyyyyyyyyyyyy
23:22	justin_smith	Trioxin: we have different standards around here
23:22	justin_smith	Trioxin: I like it because it means I don't get confused about which kind of code I'm reading
23:23	justin_smith	(if the braces are on their own lines, I'm reading an algol, if on the same line, I'm reading a lisp)
23:23	rem500	hi got it working thanks everyone
23:23	justin_smith	rem500: cool, right as you left I was like "use bash -l instead of logging out or rebooting" but I was too late
23:23	justin_smith	lol
23:24	rem500	has anyone else read the leiningen vs the ants story it's good
23:24	oddcully	rem500: kindled it
23:24	justin_smith	yup, that's where the name of our build tool comes from - ant is a popular build tool for java
23:24	oddcully	justin_smith: also salve
23:25	TEttinger	Trioxin: I totally used to feel that way. I quickly got accustomed to closing parens on the same line because it saves a lot of space
23:25	justin_smith	oddcully: salve?
23:25	oddcully	justin_smith: vim-salve
23:25	Trioxin	is "I don't do a whole lot." here a comment? http://hastebin.com/purosucode.lisp
23:25	TEttinger	docstring
23:26	justin_smith	Trioxin: it's considered the official documentation of that function
23:26	Trioxin	oooo
23:26	justin_smith	Trioxin: you can look up doc for functions using the doc function too
23:26	justin_smith	,(doc +)
23:26	TEttinger	,(defn foo "I don't do a whole lot." [x] (println x "Hello, World!"))
23:26	clojurebot	"([] [x] [x y] [x y & more]); Returns the sum of nums. (+) returns 0. Does not auto-promote longs, will throw on overflow. See also: +'"
23:26	TEttinger	,(doc foo)
23:26	clojurebot	Excuse me?
23:26	clojurebot	#'sandbox/foo
23:26	Trioxin	well, I hope I like this enough to not want to go to CL
23:26	TEttinger	,(doc foo)
23:26	clojurebot	"([x]); I don't do a whole lot."
23:26	TEttinger	there we go
23:27	justin_smith	Trioxin: cursive will use doc-strings for help popups iirc
23:27	rem500	I tried to learn clojure a month or so ago but now im back even though I'm busy
23:27	TEttinger	Trioxin: it's definitely an active community here. not sure if the same can truly be said of CL, which has been a bit more subdued I would say
23:28	Trioxin	i really wanted to try lispworks but it was a billion dollars
23:28	TEttinger	you're more likely to find up-to-date libs in clojure than for CL, I would say.
23:28	rem500	i never thought id see a lisp make a comeback
23:28	oddcully	Trioxin: better pay cfleming
23:28	Trioxin	i can use all that is java in clojure right?
23:28	TEttinger	yes
23:29	TEttinger	also, technically, all that is Scala or Groovy or any JVM language, though Java remains the easiest to call
23:29	justin_smith	clojure / java interop works very nicely going both directions
23:29	justin_smith	others might not be as easy (scala makes things harder then they should be to be sure)
23:29	Trioxin	interesting
23:29	TEttinger	Olajyd used the Scala Storm stuff from Clojure, that was... interesting
23:30	TEttinger	it worked though
23:30	Trioxin	what about mobile dev how is that coming?
23:30	Trioxin	i see lein-fruit and something for android
23:31	Trioxin	goby
23:31	justin_smith	yeah, there are projects, I've only done things with mobile via web-apps myself
23:31	TEttinger	I think, as for many many platforms, the best approach is "make a web app that the user can view on mobile and on desktop." and clojure has excellent support for that via clojurescript
23:31	Trioxin	clochure
23:31	justin_smith	TEttinger: exactly, that's what's worked for me
23:31	oddcully	i put some cljs stuff up for me mobile dudes. my last mobie projects made made me imagine killing people
23:32	TEttinger	there are also various things that let you convert a webpage to a web app. I believe Intel's XDK consumed Appcelerator Titanium
23:32	Trioxin	well I write all my mobile in HTML5 using cordova but I was thinking for heavy lifting...
23:32	TEttinger	yep, clojure works well on servers
23:32	Trioxin	or maybe better API access on the mobile platform
23:32	Trioxin	well, more not better
23:33	TEttinger	I've had clojure processes open for months without intervention. And, that was on a windows laptop with overheating issues
23:35	Trioxin	wonder how hard it would be to port my ANNs from c
23:36	TEttinger	I'd imagine a rewrite would be easier than a port, myself. probably a lot shorter
23:36	justin_smith	ANN ?
23:37	TEttinger	the approaches used in C programs and in Clojure programs are really not at all similar.
23:37	Trioxin	neural networks. been doing prediction code lately on a side project
23:37	TEttinger	have you looked at Torch at all?
23:37	Trioxin	no
23:37	TEttinger	Torch struck me as unusually high-level Lua meant for neural networks and other scientific code
23:38	TEttinger	also it has GPU acceleration for CUDA stuff
23:38	Trioxin	I started with matlab
23:38	Trioxin	torch seems cool
23:41	TEttinger	there's some stuff in that area for clojure but I haven't looked into it as much
23:42	oddcully	i'm parsing factorio files with instaparse... i hope there is some jlua...
23:42	TEttinger	I've found clojure is really really good for writing complex collection heavy code without making your brain explode
23:42	TEttinger	the immutable collections are a big contributor to brain stability
23:43	Trioxin	i see clojure has been used in robotics, that's good
23:43	justin_smith	can verify, I have an explosion-prone brain and clojure is very nice about not lighting the wick
23:44	justin_smith	or was that "can verify, am exploded brain"
23:44	Trioxin	well it doesn't look too touch. I'm sure if I can learn all these other languages I can get this
23:45	Trioxin	i'm just wanting it mostly for the paradigms
23:45	TEttinger	clojure's also hilariously good at code golf. some CL people described Clojure as a Lisp meant for writing one-liners :)
23:45	TEttinger	(part of the joke being that any lisp program can be rewritten as a one-liner)
23:45	TEttinger	(for very long lines)
23:47	Trioxin	after this I'll get into python and then my brain will be complete with programming. I've stuck with the same languages for too long and all these papers come out in PY and ppl talking about lisp paradigms. must not miss out
23:51	Trioxin	will it be difficult to understand CL knowing clojure?
23:51	Trioxin	wow you weren't overselling the java interop. that was ez
23:52	justin_smith	in my experience using clojure after common lisp and scheme, there was a break in period of being constantly annoyed about minor syntax differences, followed by everything being easy because the core building blocks were the same.
23:53	Trioxin	fair enough
23:53	justin_smith	though CL and even scheme use mutable data structures much more than we do in clojure, so they make a wider variety of programming styles possible that don't work as nicely in clojure
23:54	justin_smith	the tradeoff is that due to clojure being more constricted in style we get nice things like easy concurrency (due to eschewing the things that make concurrency really hard, like rampant mutation of data)
23:54	justin_smith	Trioxin: it is easy to code CL or scheme as if they are clojure, coding clojure like one of the others is a bit harder
23:55	justin_smith	(and probably not a good idea even when it isn't hard)