#clojure – 2015-02-02

2015-02-02

00:00	justin_s3ith	zapho53 (go-loop (let [[f, reply-chan] (<! file-chan)] (>! reply-chan (fs/readFile f))) (go (let [result-chan (chan) _ (>! file-chan ["file", result-chan]) res1 (<! result-chan) _ (>! file-chan res1 result-chan) ...] (console/log resN)) ; something like this I think
00:02	justin_s3ith	zapho53: basic idea is have a file reader in a go block, and repeatedly pass it file names and get back file contents (which happen to be file names)
00:02	zapho53	justin_smith: Thanks. Looking at it now.
00:02	justin_s3ith	zapho53: that's a rough sketch
00:02	justin_s3ith	but the basic idea should be right
00:06	zapho53	justin_smith: Sorry to say my fFirst impression is the JS is much simpler :(
00:07	justin_s3ith	zapho53: not a great example
00:07	justin_s3ith	zapho53: that is to say, there are other things core.async does better, and the simple examples won't really show it
00:08	zapho53	justin_smith: I think the JS is fairly representative of typical nested callbacks.
00:09	zapho53	justin_smith: I've chosen this simple example because I want to see what typical transposed Node -> CLJS code would look like.
00:10	zapho53	justin_smith: My concern is whether core.async makes the code easier to understand, ie. simpler. Not convinced so far :(
00:10	justin_s3ith	OK
00:10	dnolen	zapho53: I've programmed JS for 10 years professionally, JS callback code is an abomination
00:10	dnolen	zapho53: what is your example that you want to see a simpler version of of?
00:10	justin_s3ith	dnolen: you can probably do a much better job of translating that nested callback example than I did
00:11	justin_s3ith	http://pastebin.com/JM1wEz5z
00:11	zapho53	dnolen: http://pastebin.com/JM1wEz5z
00:12	dnolen	zapho53: justin_s3ith example is not the write way to do it
00:12	dnolen	zapho53: write a callback to channel helper once and for all
00:12	justin_s3ith	I'm actually glad to hear that
00:12	dnolen	s/write/right
00:13	zapho53	dnolen: OK. I've looked around a bit but can't find a simple JS -> core.async example. I'm pretty new to core.async
00:13	zapho53	dnolen: I went through Tim Baldridge's great examples but they're all in clj/cljs so couldn't quite make the connection mentally
00:15	zapho53	dnolen: I'm asking here because for me a canonical JS callback -> cljs/core.async snippet would nail it for me.
00:15	dnolen	zapho53: well first off, expecting to understand core.async in anything less than a couple of weeks is unrealistic
00:16	zapho53	dnolen: No, I've been at it for a while, on and off.
00:16	dnolen	zapho53: a core.async version of your snippet is literally a version w/o callback nothing to see here
00:16	dnolen	(let [res (<! ...) res (<! ...) ...] ...)
00:16	zapho53	dnolen: I'm half way there. Just missing a kind of mental JS equivalent. I get the conecepts as bits and pieces.
00:17	dnolen	zapho53: there is no JS equivalent, unless you are using js-csp
00:18	dnolen	zapho53: https://github.com/ubolonton/js-csp
00:19	zapho53	dnolen: The example was taken from an article by Byan Gilbert about his asynchronize library
00:21	dnolen	zapho53: anyways my earlier point still stands. With core.async for that code the only thing that will change is no callbacks
00:21	zapho53	dnolen: Are you saying my snippet doesn't contain callbacks?
00:21	dnolen	zapho53: I'm not saying anything about your snippet other than that is typical JS callback hell
00:22	dnolen	zapho53: the problem with justin_s3ith "solution" is that it's at the wrong level of abstraction you would never write it that way
00:22	zapho53	dnolen: Yes, that's why I posted it - to see how core.async would improve on it.
00:22	dnolen	zapho53: Node.js fns are have a regular form, it's trivial to write a channelizer thing
00:23	zapho53	dnolen: An example would help. Then I'll let it rest :)
00:23	dnolen	zapho53: which I already answered, it's no different if you used generators - it would look like straightline code w/ no callbacks
00:24	zapho53	dnolen: OK, thanks.
00:24	dnolen	zapho53: your example is covered in this more general case I blogged about http://swannodette.github.io/2013/08/31/asynchronous-error-handling/
00:25	dnolen	zapho53: your example is covered where ES6 generators are discussed, core.async goes way further, pretty much any example you might encounter about Go has a trivial translation
00:26	zapho53	dnolen: Didn't see that one. Looks exactly like what I was looking for. Thanks.
00:28	PigDude	dnolen: i think that zapho53 is curious about the ellipses in your example. i'd be curious too, how <! is pulling the files off some channel in the right order while the file opening is still non-blocking. also, zapho53's code provides a place to handle each file read error explicitly, whereas your blog post only demonstrates generic error-handling for a series of channel reads, but the <? becomes verbose too with specific error handling (though the
00:29	dnolen	PigDude: your question means you need to read to blog post several more times
00:29	dnolen	PigDude: and the previous blog entries too
00:31	dnolen	PigDude: but the hint is that <! is semantically blocking, but not really blocking, once that sinks in the rest makes sense
00:31	PigDude	dnolen: pardon me for not reading the previous blog post. the mechanics of <! in this case were not clear from the first post alone (which was a quick read)
00:32	dnolen	PigDude: I'm just pointing out that you were interjecting on a conversation where some expressed at least some experience /w core.async :)
00:32	dnolen	s/some/soneone
00:32	dnolen	erg someone
00:32	PigDude	dnolen: i've used core.async in production code, in a library targetting both clojure and cljs runtime
00:33	dnolen	PigDude: right, but I don't think zapho53 was expressing confusion about <!
00:33	PigDude	dnolen: but to be fair it's been a few months. either way, i could see why zapho53 would be confused.
00:33	dnolen	PigDude: could be wrong about that of course, I didn't read all the backlog
00:34	PigDude	dnolen: i could see how to somebody new to core.async the <! usage there could be confusing because without some special handling, those reads would be either blocking or non-deterministic
00:34	PigDude	dnolen: so mostly i was hoping to provoke further discussion for zapho53's sake :)
00:35	dnolen	PigDude: ok but it's simple, <! is semantically blocking w/o actually tying up a whole thread :)
00:40	PigDude	dnolen: ah, i see my confusion -- you're proposing an API used like (let [f1 (<! (read-file fname1)) f2 (<! (read-file... ] , while i was reading as (let [out (file-reader fname1 fname2 ... fnamen) f1 (<! out) f2 (<! out) ... ] ;; sorry for the confusion!
00:42	dnolen	PigDude: yeah, sorry, my point was that you could write the imperative thing w/o callbacks
00:42	PigDude	dnolen: i was thinking of the question as "how do i express something waiting for n files to be read" and came up with a clunky api in my head, the other version is definitely simpler and more flexible
00:44	PigDude	dnolen: and then i thought you were saying "he wants to hear from somebody with experience with core.async" and got a little huffy ;)
00:45	dnolen	PigDude: sorry I didn't mean to assume anything, and I sounded like I did
01:30	zacts	hi clojurists
01:42	riceandbeans	do carbs make you sleepy or energitic?
01:47	zacts	I hear energetic
01:50	riceandbeans	so is it protein that makes you sleepy?
01:57	zacts	riceandbeans: milk does, but partly I think due to the lactose
01:57	zacts	cow's milk
02:01	ddellacosta	crazy Clojurists, always on about macro-nutrients
02:07	bonanza	Hi,
02:08	bonanza	does anybody know, why I'm getting HTMLCollection by this expression: (-> dom-node .-children)
02:08	bonanza	but a normal JS array with this: dom_node.children
02:08	bonanza	where dom-node/dom_node is some HTML node in my app
02:09	bonanza	ofc I'm talking about clojurescript in the first sentence
02:39	michaelr525	hmm
02:39	michaelr525	so I wonder, compojure-api or liberator?
02:40	bonanza	michaelr525: are you refering to my question?
02:40	michaelr525	bonanza: nope, that's my own question
02:40	michaelr525	what was yours?
02:40	bonanza	"does anybody know, why I'm getting HTMLCollection by this expression: (-> dom-node .-children)"
02:40	bonanza	"but a normal JS array with this: dom_node.children"
02:41	bonanza	"where dom-node/dom_node is some HTML node in my app"
02:41	bonanza	in another words,
02:41	TEttinger	I'm wondering if .- and internal . are different
02:41	bonanza	I'm trying to translate this to clojurescript with no luck
02:41	bonanza	document.querySelector("#news-list").children[0].children[0].className
02:42	bonanza	. means refering to functions,
02:42	bonanza	.- to properties
02:42	bonanza	(like (.-length some-array))
02:42	TEttinger	so is dom_node.children getting a function or what?
02:42	bonanza	anyway, how to express this "document.querySelector("#news-list").children[0].children[0].className" in CLJS?
02:43	bonanza	well, I tried "(-> (reagent/dom-node this) .-children (aget 0) .-children (aget 0) .-className)" but I'm just getting "undefined"
02:43	bonanza	"children" is a DOM node property
02:44	bonanza	it's an array
02:44	TEttinger	(-> document (.querySelector "#news-list") .-children first .-children first .-className)
02:44	bonanza	one more thing: "(reagent/dom-node this)" actually returns a dom node, it's a library function but it doesn't matter, it's just a DOM node
02:45	TEttinger	maybe something like that?
02:45	bonanza	let's try
02:46	bonanza	I got "Uncaught Error: [object HTMLCollection] is not ISeqable"
02:46	bonanza	that's another story - I should have got a plain JS array but instead I have HTMLCollection returned
02:47	TEttinger	hm
02:47	TEttinger	try taking out the - ?
02:47	TEttinger	I really don't know how the JS underlying this works
02:50	bonanza	I tried, but then I've got an error "object is not a function",
02:51	bonanza	which is understandable since these are properties, not functions
02:51	TEttinger	I wonder if [0] is actually accessing a property 0
02:52	TEttinger	in which case you'd use (-> document (.querySelector "#news-list") .-children (get 0) .-children (get 0) .-className)
02:53	TEttinger	or, depending on weirdness levels, (-> document (.querySelector "#news-list") .-children (get "0") .-children (get "0") .-className)
02:53	bonanza	it seems like it does,
02:53	bonanza	this is the output of this expression: "(-> (.querySelector js/document "#news-list") .-children (aget 0))" => "(document.querySelector("#news-list").children[(0)])"
02:54	bonanza	get is a function for getting from normal CLJ data types,
02:54	bonanza	aget is for Java(-script) arrays
02:54	TEttinger	I was wondering if it wasn't actually an array
02:55	bonanza	It is - following expression works as exprected: (-> (.querySelector js/document "#news-list") .-children (aget 0))
02:55	bonanza	i.e. it selects first ("0") node from "children" of #news-list
02:56	bonanza	but when I try to get first child of that node, I get "undefined"
02:56	TEttinger	uh hm. check its type however you do that in cljs?
02:56	TEttinger	(doc type)
02:56	clojurebot	"([x]); Returns the :type metadata of x, or its Class if none"
02:58	bonanza	yeah, but what node are you refering to?
02:58	TEttinger	first ("0") node from "children" of #news-list
02:58	bonanza	function HTMLDivElement() { [native code] }
02:59	TEttinger	yeah I have no idea how this works
02:59	bonanza	it's a normal HTML div element, it's just a way CLJS prints it
02:59	TEttinger	michaelr525: you seem to know something about cljs, which is about 10x more than I can say
03:06	michaelr525	hmm
03:06	michaelr525	what?
03:06	clojurebot	what is not a bug
03:06	michaelr525	what
03:10	Mr0rris0	lol it said that to me too
03:10	Mr0rris0	what?
03:10	clojurebot	what is http://gist.github.com/306174
03:10	Mr0rris0	what?
03:10	clojurebot	what with pervasive side effects
03:10	Mr0rris0	what?
03:10	clojurebot	what is cells
03:10	michaelr525	TEttinger: I've been disconnected. What was the problem?
03:11	Mr0rris0	what?
03:11	clojurebot	what is exceptions
03:12	TEttinger2	michaelr525: bonanza is having issues with html elements not acting like collections
03:13	bonanza	or - acting like HTMLCollections, not as arrays (as I'd expect)
03:13	michaelr525	why do you expect them to be arrays?
03:15	bonanza	because I'd like to get first elements from them,
03:16	bonanza	or, in other case (not presented here), I need to loop over such array
03:17	zacts	how can I easily convert a vector of vectors into a map of maps (map the data structure)?
03:18	michaelr525	bonanza: (-> (.querySelector js/document "#mich") (.-children) (aget 0))
03:18	bonanza	in other words, I simply need this "(-> some-HTML-node .-children (aget 0) .-children (aget 0))" to be equal to this "some_HTML_node.children[0].children[0]"
03:18	bonanza	michaelr525: yeah, that works,
03:19	bonanza	problem is when I have two such expressions in a row
03:19	bonanza	like in above example
03:19	michaelr525	let me try a sec
03:20	michaelr525	bonanza: works for me
03:20	michaelr525	bonanza: maybe your html structure doesn't match what you expecet
03:20	bonanza	simply put, this "(-> (reagent/dom-node this) .-children (aget 0))" gives me a first parent (some div in my case)
03:20	michaelr525	(-> (.querySelector js/document "#mich") (.-children) (aget 0) (.-children) (aget 0))
03:21	bonanza	but this "(-> (reagent/dom-node this) .-children (aget 0) .-children (aget 0))" gives me nothing, where there are children of that node (one child, to be exact)
03:22	bonanza	this is my compiled invocation (no optimizations): "((reagent.core.dom_node.call(null,this$).children[(0)]).children[(0)])"
03:22	michaelr525	what does (reagent/dom-node) return?
03:23	TEttinger3	zacts: ##(let [vecvec [["a" "A" "b" "B"] ["z" "Z" "y" "Y"]]] (into {} (map #(into {}) vecvec)))
03:23	lazybot	clojure.lang.ArityException: Wrong number of args (1) passed to: sandbox6330/eval12173/fn--12174
03:23	TEttinger3	zacts: ##(let [vecvec [["a" "A" "b" "B"] ["z" "Z" "y" "Y"]]] (into {} (map #(into {} %) vecvec)))
03:23	lazybot	java.lang.ClassCastException: java.lang.Character cannot be cast to java.util.Map$Entry
03:23	TEttinger3	gah
03:23	bonanza	michaelr525: just a plain DOM node
03:24	bonanza	michaelr525: https://github.com/reagent-project/reagent/blob/master/src/reagent/core.cljs#L151
03:24	bonanza	reagent is a CLJS React wrapper
03:25	bonanza	michaelr525: in this case, "root node of a mounted component" is my #news-list div
03:26	TEttinger3	zacts: ##(let [vecvec [["a" "A" "b" "B"] ["z" "Z" "y" "Y"]]] (apply hash-map (map #(apply hash-map %) vecvec)))
03:26	lazybot	⇒ {{"a" "A", "b" "B"} {"z" "Z", "y" "Y"}}
03:26	michaelr525	bonanza: does it work fine when you use javascript api and not dom-node?
03:26	TEttinger3	that has a map as a key and a map as a value
03:27	michaelr525	what's that .' syntax btw?
03:27	bonanza	michaelr525: yes - "document.querySelector("#news-list").children[0].children[0]" gives me desired node
03:28	michaelr525	bonanza: and dom-node returns the same type as querySelector?
03:28	bonanza	the thing is that I just have a container which has "content" and "scrollbar", and after mounting that container node in a DOM, I need to select the "scroller" (div inside) of a "scrollbar"
03:29	bonanza	michaelr525: yes, it returns a plain DOM node (as in http://facebook.github.io/react/docs/working-with-the-browser.html)
03:29	michaelr525	do you wait until it's rendered?
03:30	bonanza	yes, because React works that way, it operates on "Virtual DOM"
03:31	bonanza	and to get a plain DOM node, you have to wait till it's "mounted" into, then you can select it
03:32	michaelr525	could you maybe "inspect" the desired element in chrome dev tools and paste a screenshot somewhere?
03:36	bonanza	michaelr525: screenshot of a page?
03:37	bonanza	or a dom structure?
03:37	drakezhard	Hi does anyone know how to use (proxy) to extend a class?
03:38	bonanza	michaelr525: OK, I'll give you a DOM structure to see
03:43	bonanza	michaelr525: there's it: http://i.imgur.com/IC0qa2e.jpg
03:45	michaelr525	hmm
03:45	michaelr525	looks ok
03:45	Viesti	argh
03:46	Viesti	trying to make a custom reporter for cljs.test
03:46	Viesti	targeting karma
03:46	Viesti	for some reason, I can't pass a custom :reporter key to the environment :(
03:47	michaelr525	bonanza: maybe try fetching them one at a time and inspecting their types and content?
03:47	Viesti	(run-tests (test/empty-env :karma) 'xxx.app-test)
03:47	Viesti	this should probably do it
03:48	michaelr525	bonanza: browser-repl for example prints result types like that: #<[object HTMLDivElement]>, #<[object HTMLCollection]>
03:48	michaelr525	so it's easy to know what you are getting
03:50	bonanza	michaelr525: well, the problem is that if I print result by plain js/console.log I got a HTMLCollection, like [item: function, namedItem: function]
03:50	bonanza	i.e. it prints like this, when I click, there is my "div.scroller" at [0], but I cannot select this by (aget 0)
03:51	michaelr525	i meant to use cljs repl
03:52	bonanza	michaelr525: result will be the same as printing it by ex. (println ...)
03:53	bonanza	michaelr525: because it just uses IPrettyPrint interface under the hood
03:54	michaelr525	so when you (println (dom-node "#news-list")) you get HTMLCollection?
03:55	michaelr525	and (println (-> (dom-node "#news-list") (-.children)))?
03:55	michaelr525	and (println (-> (dom-node "#news-list") (-.children) (aget 0))?
03:55	michaelr525	i think you get my point
03:55	michaelr525	did you try debugging like that?
03:56	bonanza	michaelr525: actually, (println (reagent/dom-node this)) yields "#<[object HTMLDivElement]>"
03:56	bonanza	and that's normal since it's a div, after all
03:56	michaelr525	right
03:57	michaelr525	what about the next step and the next one?
03:57	Viesti	has anyone tried to make a custom reporter for cljs.test?
03:58	bonanza	michaelr525: http://pastebin.com/wwLndRDJ
04:00	michaelr525	bonanza: ok, just go on and when you get a result you didn't expect, inspect the problematic node at hand. that's what i'd do..
04:01	bonanza	michaelr525: I'll definately try :)
04:01	bonanza	michaelr525: thanks for your effort
04:05	michaelr525	let me know what you came up with
04:24	zacts	ah thanks
04:41	dysfun	is there a builtin equivalent to (fn [seq pred] (let [a (filter pred seq) b (remove pred seq)] [a b])) ?
04:41	dysfun	probably with the argument order reversed
04:47	Glenjamin	,(doc split-with)
04:47	clojurebot	"([pred coll]); Returns a vector of [(take-while pred coll) (drop-while pred coll)]"
04:47	Glenjamin	oh, not quite
04:51	hyPiRion	it's just (juxt filter remove)
04:53	hyPiRion	group-by is a generalisation if you need to separate values even more
04:56	dysfun	juxt is good, thanks
04:56	dysfun	and does anyone know of a great example of cond-> ?
04:56	dysfun	it's very difficult to google for
05:01	hyPiRion	dysfun: (cond-> foo true (assoc :a :b)) acts as (assoc foo :a :b), and (cond-> foo false (assoc :a :b)) acts as foo only
05:01	hyPiRion	and they chain
05:02	hyPiRion	,(map (cond-> % (odd? %) (* 2) (even? %) (* 3) (neg? %) -) (range -3 3))
05:02	clojurebot	#<CompilerException java.lang.RuntimeException: Unable to resolve symbol: % in this context, compiling:(NO_SOURCE_PATH:0:0)>
05:02	hyPiRion	,(map #(cond-> % (odd? %) (* 2) (even? %) (* 3) (neg? %) -) (range -3 3))
05:02	clojurebot	(6 6 2 0 2 ...)
05:05	dysfun	hrm, so effectively a conditional pipeline?
05:05	hyPiRion	yep
05:06	dysfun	so this might be useful, for example for performing a bunch of data correction?
05:06	dysfun	if data displays this brokenness, fix it this way?
05:07	fairuz	anyone use Tinkerpop stack with clojure here? :)
05:07	dysfun	fairuz: did a very small amount with the orientdb library
05:07	hyPiRion	dysfun: yeah, that's an example
05:07	dysfun	hyPiRion: hrm. any other good cases you can think of, in terms of the high level?
05:13	hyPiRion	dysfun: Well, afaik it was introduced because Rich (?) had a lot of code which looked like this:
05:13	hyPiRion	(let [a input, a (if (old-style? a) (update-in a [:res] update-to-new) a), a (if (negative-results? a) (fix-results a) a)] (do-something-with a))
05:14	hyPiRion	With cond->, that's (let [a (cond-> in (old-style? in) (update-in [:res] update-to-new) (negative-results? in) (fix-results))] (do-something-with a))
05:16	dysfun	right, so again that's pretty much a data fixing up use case :)
05:17	Glenjamin	it's fairly good in speccing ring middleware
05:17	hyPiRion	Well, that's the examples I managed to come up with right now :p
05:17	Glenjamin	(-> app (cond-> dev wrap-stacktrace))
06:20	dysfun	Glenjamin: ooh yes, that's quite a nice one
06:20	dysfun	in fact, i've got a pattern for dealing with that that i'm not happy with, so i'm going to rewrite it in that manner
06:22	Glenjamin	it's actually not ideal for that, because you can only do one middleware per condition
06:22	dysfun	that's fine, they're already in functions for grouping
06:22	Glenjamin	unless you do (cond-> test? (-> () () ()))
06:22	dysfun	hrm, that could work
06:33	Viesti	hmm
06:33	Viesti	is there something like alter-var-root for ClojureScript?
06:34	Glenjamin	you can probably just use def
06:34	Viesti	hmm so how do I override a def in another namespace?
06:41	CookedGr1phon	Hey all. I want something which behaves like a promise mixed with an atom. Is there such a thing without two derefs?
06:42	CookedGr1phon	i.e. I want to promise and deliver later, block on read until it's delivered, but also with the possibility of changing it later on
06:44	Glenjamin	CookedGr1phon: i don't think that exists out of the box, but you could probably reify something
07:03	clgv	CookedGr1phon: maybe you should separate both concerns
07:03	clgv	CookedGr1phon: as soon as it is delivered you can wrap it in an atom and pass that along
07:04	CookedGr1phon	that's pretty much what I've done
07:06	clgv	well, then you do not need something merged ;)
07:07	CookedGr1phon	I meant that's what I've done since asking the question
08:21	LukasK	Hi, i tried to add the clojars repo to my maven nexus but it is not working
08:23	clgv	LukasK: did you add it as "proxy repository"?
08:25	LukasK	our nexus admin did, the type of the repo is proxy. but when i click on browse storage (nexus browser UI) there is just a corrupt archetype-catalog.xml
08:26	LukasK	browse remote is working
08:26	clgv	LukasK: and the index download is enabled as well?
08:26	LukasK	i dont think so
08:26	clgv	LukasK: it is enabled by default if you add a new proxy rep as far as I have seen
08:27	clgv	when you enable that, you can search for clojars artifacts in your nexus instance
08:27	LukasK	ok i ask my nexus admin if he enabled the index download, but if it is enabled by default and it is not working there must be another problem
08:28	clgv	LukasK: clojars.org/repo is the location
08:30	clgv	LukasK: do you know by any chance how your admin detects "failed logins"? nexus has an rss feed but you cant use that for fail2ban :(
08:32	LukasK	sorry clgv, i have no idea
08:32	clgv	LukasK: ok
08:32	clgv	it's pretty weird to have an rss feed for it but not to include it in the log files...
09:05	LukasK	hmm nexus can't download the clojars index
09:07	clgv	LukasK: mine did so yesterday..
09:20	LukasK	hmm strange
09:22	LukasK	ah it's working :P
09:22	LukasK	just took forever but now it is working :P
09:49	Scorchin	Hello, I'm using cider in emacs now instead of nREPL. Everything looks good so far, but it's not running the tests for a Clojure test when I run `C-c ,` or `C-c C-,`. It just shows "Testing..." in my mode line but no output. Has anyone seen this before and know what the fix is?
10:00	Scorchin	Never mind, figured it out. Had to add `[cider/cider-nrepl "0.8.2"]` to my :user :profiles hash
10:37	dnolen	just release ClojureScript 0.0-2760, fixes some ns parsing regressions introduced by 0.0-2755
10:39	clgv	dnolen: regarding the versions. is there a roadmap or essential features that need to be done before having some kind of 1.0 release?
10:40	dnolen	clgv: Google Closure Module support, fixing tons of bugs (> 100 open issues in JIRA), optional bootstrap at a minimum
10:41	clgv	dnolen: ok, sounds like a lot of work
10:41	dnolen	clgv: yep
10:41	daniel__	what about 0.1? :)
10:50	muhuk	Greetings. Which convention do you use for constructors in your libs; foo/make-foo or foo/create or foo/new ?
10:50	Glenjamin	module.exports = function(){}
10:51	Glenjamin	oh, wrong channel
10:51	Glenjamin	duh
10:51	Glenjamin	ignore me
10:51	stuartsierra	muhuk: I use just "foo" if it creates a new Foo; "new-foo" if I want to distinguish from returning a pre-existing foo; and "create-foo" if it has side effects (e.g. updating a database)
10:53	gfredericks	concoct-foo
10:53	gfredericks	discover-foo
10:53	muhuk	stuartsierra: so foo/foo, it's likely to be imported as foo
10:53	gfredericks	invent-foo
10:53	llasram	gfredericks: derive-foo ?
10:53	llasram	gfredericks: ooh: evolve-foo
10:53	gfredericks	imagine-foo
10:54	gfredericks	prove-foo-by-construction
10:57	stuartsierra	I generally like to name non-side-effecting functions as nouns for the thing they return.
10:57	stuartsierra	My side-effecting functions are verbs.
10:57	stuartsierra	So "foo" or "new-foo" are pure constructors.
10:57	stuartsierra	"create-foo" has side-effects.
10:57	muhuk	stuartsierra: makes sense. Thanks!
10:58	stuartsierra	And yes, I do end up with a lot of foo/foo, but it doesn't really bother me.
10:58	stuartsierra	I also break these rules all the time :)
11:01	uris77	rules are meant to be broken :)
11:02	gfredericks	I like breaking the "rules are meant to be broken" rule
11:03	clgv	gfredericks: no self-referential statements allowed! you probably know what this has done to mathmatics ;)
11:04	gfredericks	arguably the prior statement was already self referential
11:04	TimMc	(defn allocate-tmp-stack-frame [] nil)
11:05	gfredericks	(inc TimMc)
11:05	lazybot	⇒ 88
11:05	clojurebot	No entiendo
11:05	hyPiRion	,(let [x [1]] (aset (.tail x) 0 2) x) ; <- breaking the rules
11:05	clojurebot	[2]
11:05	clgv	gfredericks: maybe it was just a suggestion ;)
11:05	TimMc	I suppose that should have a ! at the end.
11:05	clgv	gfredericks: or an observation
11:06	clgv	hyPiRion: that's to easy to spot - convert an array to a vector and then modify the underlying array values ;)
11:07	hyPiRion	or just do this
11:07	hyPiRion	(let [x [1]] (aset (.tail x) 0 x) x)
11:13	sdegutis	I can't help but notice tons of similarities between Clojure and Haskell.
11:17	hipsterslapfight	well they're both functional languages sure
11:18	clgv	but on of them has a, let's say, "suboptimal" syntax ;)
11:18	sdegutis	hipsterslapfight: They both have things like comp and partial, they both have plenty of ways to operate on lists, they both encourage writing small, pure functions...
11:19	hipsterslapfight	about the only thing i really miss from haskell is auto currying
11:20	sdegutis	hipsterslapfight: you don't miss the compile-time type safety?
11:20	hipsterslapfight	sdegutis: no, if that were the case i'd be using haskell still :v
11:20	CookedGr1phon	hipsterslapfight: but in return you get varargs
11:21	hipsterslapfight	CookedGr1phon: sure, i have mixed feeligns on variadic functions though ...
11:24	tcrayford____	sdegutis: haskell was an explicit inspiration for rich when designing cleaxjure
11:24	sdegutis	tcrayford____: huh, I didn't know that
11:24	sdegutis	That explains a lot of the similarities.
11:27	sdegutis	Are Clojure's lazy sequence functions essentially lazy in the same way as any of Haskell's list functions?
11:30	stuartsierra	sdegutis: not really
11:30	sdegutis	oh ok
11:30	stuartsierra	I mean, you can use them to achieve similar ends, but the mechanism is totally different.
11:30	stuartsierra	In Haskell, evaluation itself is lazy, even function arguments.
11:30	stuartsierra	List laziness just falls out of that.
11:31	stuartsierra	Clojure functions always use strict evaluation semantics. Lazy sequences are a special-purpose data structure for achieving laziness in one specific area.
11:34	tbaldridge	Haskell's laziness can also have the same problems as lazy seqs in Clojure. In haskell it's possible to get into a situation where a while chain of calls are held in memory since you haven't executed them yet. Those calls could result in a single integer which would have been cheaper to evaluate when they were constructed.
11:34	tbaldridge	So I kindof compare that to some of Clojure's issues with "holding the head
11:34	tbaldridge	... of seqs"
11:39	mdrogalis	tbaldridge: Are promise channels out in any core.async releases yet?
11:39	tbaldridge	not that I know of, puredanger would be the one to ask about that
11:39	mdrogalis	tbaldridge: Okay, thanks man.
11:49	sdegutis	tbaldridge, stuartsierra: ahh, that's very informative, thank you
12:11	zerokarmaleft	it's all just lambda calculus
12:11	clgv	$karma zerokarmaleft
12:11	lazybot	zerokarmaleft has karma 0.
12:16	llasram	(inc zerokarmaleft)
12:16	lazybot	⇒ 1
12:17	hellofunk	lol that was scary there for a moment
12:24	zerokarmaleft	some people just want to watch the world burn
12:30	dnolen	cfleming: ping
12:30	csd_	Is there any way for me to have a function use global var foo of the current namespace calling the function, rather than global var foo of the namespace the function is in?
12:31	llasram	csd_: That honestly sounds horrific :-). Dynamic vars are the closest you'd get (fortunately)
12:32	csd_	its for testing purposes
12:32	csd_	i have a function that references a global ref, and i want to test the function
12:33	csd_	(open to alternatives)
12:33	llasram	csd_: It's not without its own limitations, but maybe `with-redefs`?
12:33	justin_s3ith	csd_: it can be hacked with a macro
12:33	justin_s3ith	but that's macro abuse
12:34	justin_s3ith	brb getting rid of this silly nick
12:34	csd_	with-redefs looks like it would do the trick
12:35	Frozenlock	Is there a way to list all the methods of a protocol?
12:37	justin_smith	Frozenlock: look up its source?
12:37	justin_smith	Frozenlock: it should be possible via reflection too actually, but all the methods should have to be right there in the protocol def, so I think that's easier
12:37	csd_	llasram-- thx, that works. what would the typical approach be when someone is trying to test a function that uses global state?
12:38	justin_smith	csd_: :P stop using global state maybe?
12:38	csd_	but i need it
12:38	justin_smith	OK
12:38	Frozenlock	justin_smith: yeah I did that, but I get "Can't define method not in interfaces" when I try a method defined in the source :-/
12:38	justin_smith	Frozenlock: that makes me think the arg count doesn't match
12:38	llasram	csd_: I'm actually with justin_smith on this one. I'm skeptical of general actual need for global state
12:39	llasram	(modulo wanting to use a library which is written to depend on it)
12:39	justin_smith	csd_: it should be possible to segregate the management of global state from program logic
12:39	csd_	llasram, writing an IRC server?
12:39	Frozenlock	justin_smith: hmm maybe... let me check that.
12:39	justin_smith	csd_: if you really need global state, make a logicless shim (which won't need testing) plus a pure function with all the logic (easy to test)
12:40	justin_smith	csd_: very similar to the trick of using a function to generate the expansion for a macro
12:40	llasram	csd_: Why would that necessitate process-global state, where you wouldn't be able to have e.g. the same JVM running multiple servers simultaneously on different ports?
12:40	csd_	sorry i don't understand the question
12:41	justin_smith	csd_: what if an app needs two or more instances of what your code implements
12:41	llasram	csd_: I'm saying that just because you have state doesn't mean it needs to be "global"
12:41	Frozenlock	justin_smith: Everything looks okay. Would you mind checking this very short example and telling me if there's any obvious problem? https://www.refheap.com/96802
12:41	csd_	i'm implementing global state with a ref, and each client will be its own thread, and will have functions to access global state
12:42	csd_	this is an area i'm pretty ignorant in so i'm learning as i go
12:42	llasram	csd_: But why does it have to be global? Why don't the threads start with a reference to the ref passed in as an initial argument instead?
12:43	tbaldridge	csd_: you could still use a ref, but pass it in to each client thread when you construct it
12:43	csd_	i was initially thinking of doing it that way, llasram, but someone smarter than i suggested otherwise, asking why should a single connection need access to everything
12:44	tbaldridge	bleh, didn't see what llasram wrote
12:45	justin_smith	csd_: if it's global, then everyone get's full access, that's no different than passing it as an arg
12:45	justin_smith	*gets
12:46	justin_smith	Frozenlock: all I can think is maybe a typehint that the result is Object? that seems like an odd thing to need though.
12:46	csd_	, do you know of any good reading on architecting this sort of thing?
12:46	clojurebot	#<CompilerException java.lang.RuntimeException: Unable to resolve symbol: do in this context, compiling:(NO_SOURCE_PATH:0:0)>
12:46	csd_	sorry my ERC is broken :-/
12:47	csd_	-- that was addressed to you
12:47	csd_	jesus
12:47	llasram	csd_: https://github.com/stuartsierra/component
12:47	justin_smith	csd_: sicp covers the general concept of transforming global state into explicit args iirc, but that's a tiny part of what it covers, and is actually pretty simple once you do it a few times
12:47	justin_smith	csd_: and yeah, component has some stuff built around that idea too
12:48	justin_smith	(inc llasram)
12:48	lazybot	⇒ 47
12:48	csd_	ok i'll check it out thanks
12:48	justin_smith	almost forgot to inc dnolen for saving that newb from my shitty code last night
12:48	justin_smith	(inc dnolen)
12:48	lazybot	⇒ 20
13:06	Frozenlock	,(clojure.pprint/pprint (->> (clojure.reflect/reflect clojure.lang.IAtom) :members (map :name)))
13:06	clojurebot	#<ClassNotFoundException java.lang.ClassNotFoundException: clojure.pprint>
13:06	Frozenlock	,(->> (clojure.reflect/reflect clojure.lang.IAtom) :members (map :name))
13:06	clojurebot	#<CompilerException java.lang.ClassNotFoundException: clojure.reflect, compiling:(NO_SOURCE_PATH:0:0)>
13:07	Frozenlock	grr... here's the result (swap swap swap reset swap compareAndSet)
13:07	justin_smith	Frozenlock: perhaps you need to require some namespaces
13:07	justin_smith	,(require 'clojure.pprint 'cojure.reflect)
13:07	clojurebot	#<FileNotFoundException java.io.FileNotFoundException: Could not locate cojure/reflect__init.class or cojure/reflect.clj on classpath.>
13:07	justin_smith	well, at least we have the pprint
13:07	Frozenlock	:-p
13:08	Frozenlock	I just wanted to show what was visible... 'deref' is not there. Any ideas why?
13:09	felixflores	Can anyone tell me why transit is not recognizing java.sql.Timestamp even after I've defined a handler for it? https://gist.github.com/felixflores/20a8cfa034628cae09ac
13:11	Frozenlock	oh dang... deref might be a IDeref method.
13:11	clgv	Frozenlock: there is IDeref
13:11	clgv	ah you got it
13:12	clgv	future, promise and ref implement IDeref as well
13:12	R0B_ROD	!seen godd2
13:13	clgv	it's "$seen" afaik
13:13	justin_smith	$seen godd2
13:13	lazybot	godd2 was last seen quittingPing timeout: 246 seconds 20 hours and 56 minutes ago.
13:13	clgv	strange order
13:19	felixflores	ignore me. I made a stupid mistake. I didn't send the appropriate MIME type
13:21	justin_smith	Frozenlock: yeah, I see that too, no actual deref in the IAtom methods
13:21	clgv	how do I find out the client IP from a ring request?
13:21	justin_smith	Frozenlock: do you remember if that was maybe protected?
13:21	clgv	I need that for monitoring abuse of the web app
13:21	Frozenlock	justin_smith: No, it looks like deref is an IDeref method, not an IAtom one.
13:22	justin_smith	Frozenlock: aha, for some reason I saw deref in the IAtom source, maybe I was mistakenly looking at an old version of the code
13:22	clgv	ah there is :remote-addr
13:23	Frozenlock	justin_smith: I saw it too (https://github.com/clojure/clojure/blob/master/src/jvm/clojure/lang/Atom.java#L29) which is why I didn't even think of looking in other interfaces.
13:27	tbaldridge	Frozenlock: there is a IDeref interface.
13:28	R0B_ROD	thanks justin_smith
14:20	ben_vulpes	anyone have a handle on clojure-west promo codes?
14:20	ben_vulpes	i missed the early reg :(
14:25	justin_smith	ben_vulpes: yeah that was over fast, and you're probably in the same boat I am where you would be buying your own ticket
14:26	noonian	us pdxers late to the party should all register together for the 10% discount
14:28	justin_smith	noonian: sounds like an excellent plan
14:28	justin_smith	"clojerk discount"
14:28	noonian	lol nice
14:50	crazydiamond	Hi. Can I wrap function (or macro?) deftest into my function? I.e. to have bunch of tests generated (e.g. to test single function on multiple data)?
14:51	slipset	hmm, maybe look into :pre and :post
14:51	slipset	which are like asserts?
14:51	slipset	or, better yet, could you show us an example of what you're trying to achieve?
14:52	crazydiamond	ah.. design by contract? :D
14:53	justin_smith	crazydiamond: you can define a test with defn similarly to how :pre and :post are defined https://clojuredocs.org/clojure.core/test
14:53	justin_smith	yeah, :pre and :post are more similar to design by contract, and :test is for tdd
14:53	justin_smith	though frequently/usually people directly use assert or clojure.test/deftest
14:53	crazydiamond	yep, I want TDD
14:54	crazydiamond	but I have repetition, like this: http://dpaste.com/09RV7F4
14:54	slipset	crazydiamond: if you're into TDD, checkout midje and autotest
14:54	justin_smith	crazydiamond: you can always define a function to be called inside tests
14:55	justin_smith	crazydiamond: calling deftest inside defn seems odd to me
14:55	hyPiRion	gfredericks: Implementation of factorial using a Y combinator:
14:55	hyPiRion	,(((->(->>(#(% %)(->>(!(->>(($ $)?)#()(->[?])))#()(->[$]))))(->> #()(->[!])))(->>(->>(({(=(+)$)#()}(= =)#( $(!(- $(*))))))#()(->[$]))#()(->[!]))) 10)
14:55	clojurebot	3628800
14:55	crazydiamond	justin_smith, yes, but every time... if I would have 50 tests, that would be 50 functions...
14:55	arrdem	(inc hyPiRion) ;; that's revolting but you deserve it.
14:55	lazybot	⇒ 64
14:56	justin_smith	crazydiamond: if there is duplicated logic between the tests, you can define one function, if there isn't there's no point in putting it in a function
14:56	hyPiRion	I implemented SKI as well. Pretty sure that proves Swearjure is turing complete, no?
14:56	slipset	crazydiamond: also, maybe you should look into propertybased/generative testing
14:57	justin_smith	crazydiamond: also, that defn that calls deftest is not doing what you think it does
14:57	slipset	seems like you're using your functions to generate test-data for your tests?
14:57	justin_smith	crazydiamond: you are repeatedly redefining the same test
14:57	crazydiamond	justin_smith, yep. I realized that. my test doesn't fail (but it should)
14:57	crazydiamond	huh
14:57	arrdem	hyPiRion: now if only it were TCO'd it'd be useful as well
14:57	justin_smith	crazydiamond: test_run_func would need to be a macro
14:58	justin_smith	crazydiamond: also, camelcase and snake case for functions is a bad idea, it confuses readers. CamelCase is for classes, snake_case is for json / db keystrings. For clojure vars use kebab-case
14:59	hyPiRion	arrdem: Hrm. Need to find a way to implement trampoline.
14:59	slipset	hyPiRion: you need to stop with this hand crafting nonsense and write a clojure2swearjure code-walking macro
15:00	slipset	or something ;)
15:00	hyPiRion	slipset: I'm not that far away from doing that actually
15:00	slipset	Don't you write compilers for a living?
15:01	hyPiRion	yes
15:01	hyPiRion	I found the SKI properties while working on my swearjure interpreter.
15:02	crazydiamond	thanks for help
15:02	Frozenlock	What's the clojure way of doing the 'extends' part of this: "final public class Atom extends ARef implements IAtom" ?
15:02	crazydiamond	I wonder if I may just change defn to defmacro for test_run_func
15:02	hyPiRion	(Clarification: I don't implement a swearjure interpreter for work)
15:02	tbaldridge	Frozenlock: you can do it with proxy, but I'm not sure that's what you want
15:02	justin_smith	Frozenlock: deftype could do it, or proxy
15:02	tbaldridge	Frozenlock: what are you trying to do?
15:02	justin_smith	wait, maybe deftype can't
15:03	Frozenlock	adding IRef to a deftype without reimplementing all the methods.
15:03	justin_smith	Frozenlock: for interfaces, you can use deftype or defrecord to extend, for concrete classes you need proxy or gen-class I think
15:04	justin_smith	Frozenlock: oh, that's easy - clojure won't complain about partial coverage at all
15:04	justin_smith	Frozenlock: just add an IRef clause to your deftype
15:04	tbaldridge	yeah, it'll just throw NotImplementedException on any unspecified methods
15:04	justin_smith	if/when they are called :)
15:04	Frozenlock	Well, I want those methods...
15:04	justin_smith	Frozenlock: wait, what?
15:05	justin_smith	you want methods from an interface, but don't want to implement them?
15:05	Bronsa	justin_smith: he's ok with the impl provided by ARef
15:05	justin_smith	ahh, right
15:05	slipset	tbaldridge: just curious, the idea of implementing the go-macro as a state-machine, is that something that falls out of Hoare's CSP, the Go-lang implementation of CSP or out of the bright heads like yourself?
15:05	Frozenlock	Bronsa: yes, that.
15:06	Bronsa	Frozenlock: genclass/proxy are the only way to do that ATM
15:06	Frozenlock	If you look at this https://github.com/clojure/clojure/blob/master/src/jvm/clojure/lang/Atom.java#L17, you can see that Atom is just using ARef.
15:06	justin_smith	Frozenlock: you can do that kind of thing with proxy or gen-class
15:06	justin_smith	or just write some java
15:07	Bronsa	or use a custom version of clojure https://github.com/Bronsa/clojure/blob/defclass/src/clj/clojure/interop.clj#L27 ;)
15:08	justin_smith	Bronsa: I'm not sure whether I love that or hate it... definitely one of the extremes, just not sure which yet.
15:10	{blake}	OK, so I'm now maintaining/expanding this app I've built, at the very bottom of which, there's a call (.javaMethod obj). And now I've discovered obj MAY be nil. I can catch the nil going in, or I can make the call at the bottom return nil instead of trying to make the call.
15:11	justin_smith	{blake}: some-> can be helpful for either (depending on your current code)
15:12	justin_smith	,(some-> "hello" .toUppercase)
15:12	clojurebot	#<IllegalArgumentException java.lang.IllegalArgumentException: No matching field found: toUppercase for class java.lang.String>
15:12	justin_smith	,(some-> "hello" .toUpperCase)
15:12	clojurebot	"HELLO"
15:12	justin_smith	,(some-> nil .toUpperCase)
15:12	clojurebot	nil
15:12	{blake}	justin_smith: Interesting. I think. =P
15:13	justin_smith	{blake}: easy enough to turn (.meth O) into (some-> O .meth) and get free short-circuiting on nil
15:13	ianhedoesit	,(.toUpperCase "hello")
15:13	clojurebot	"HELLO"
15:13	justin_smith	of course this works nicely with chaining
15:13	ianhedoesit	,(.toUpperCase nil)
15:13	clojurebot	#<NullPointerException java.lang.NullPointerException>
15:14	ianhedoesit	neat
15:14	{blake}	justin_smith: Yeah...Hmmm. That argues for doing it higher level, I think. Because I can make the least traumatic change that, and it's easy to apply as-needed without making large assumptions about...things.
15:15	justin_smith	,(some-> {:a 0} :b inc) ; also useful without interop
15:15	clojurebot	nil
15:15	justin_smith	,(some-> {:a 0} :a inc)
15:15	clojurebot	1
15:17	{blake}	(inc justin_smith)
15:17	lazybot	⇒ 179
15:27	muhuk	I have a function that takes a namespace as a keyword like this (foo :bar.baz.foobar), it needs to call some bar.baz.foobar/bat then. But bat is not always named bat, it can be something else for another namespace. How do you suggest I set up the protocol here?
15:27	muhuk	Having an alias of bat with a fixed name comes to mind: (def that-thing bat)
15:32	amalloy	muhuk: that seems like a really weird function to write. why do you have a function looking up arbitrary things in arbitrary namespaces represented as keywords?
15:33	muhuk	amalloy: :) good question
15:34	Mr0rris0	maybe its not arbitrary?
15:34	muhuk	amalloy: it's for a library I'm working on. It provides different backends, and it is extensible
15:34	muhuk	amalloy: that's why I'm not creating a static table
15:34	amalloy	okay, so put things in a map?
15:35	amalloy	namespaces are great for compile-time lookups, and maps are great for runtime lookups
15:35	AeroNotix	muhuk: you might want to use defgeneric
15:35	AeroNotix	uhm, defmulti, sorry
15:35	AeroNotix	too much CL
15:36	justin_smith	muhuk: why not a map from keyword to implementation? or a defmulti yeah
15:36	muhuk	amalloy: I think I couldn't describe my situation. fn in question here: https://github.com/muhuk/clecs/blob/master/src/clecs/core.clj I'll take a param to go find the backend.
15:36	justin_smith	muhuk: the keyword -> symbol -> var-in-ns -> function thing is so indirected
15:37	muhuk	AeroNotix: that's a cool idea, except it'll be a bit backwards maybe
15:37	muhuk	justin_smith: hi
15:37	muhuk	justin_smith: yes, you're right
15:38	justin_smith	muhuk: depending on your other needs, any number of those steps in the middle could be skipped by just providing the thing it dereferenced to
15:38	amalloy	muhuk: so like, your caller, whoever is calling this function, has to pass you a namespace they wrote, right? as a keyword, for some reason. and in that namespace there are functions they had to write, yes?
15:38	justin_smith	eg. providing a symbol instead of keyword, var instead of symbol, function instead of var
15:39	muhuk	amalloy: they, or 3rd parties. Not known by clecs.
15:39	AeroNotix	it sounds like you might want a protocol then
15:39	justin_smith	yeah, I would use a multimethod or protocol, that's exactly what those things are for
15:39	amalloy	so, it's no more trouble for them to instead pass you a map, which contains the functions that would have been in a namespace
15:39	AeroNotix	if you know what you're going to call on the object, you pass in an instance of that and call the right methods on it
15:40	muhuk	justin_smith: suppose I give you a backend, as a lein dep, you'd need to read the source to find out which fn to use.
15:41	muhuk	justin_smith: but you already know the ns (hopefully)
15:41	justin_smith	muhuk: why? you pass me something implementing my protocol or multimethod, I call the protocol / multi methods
15:41	AeroNotix	justin_smith: this
15:41	justin_smith	muhuk: I don't need to know anything about your ns in order to call implementations of my protocol
15:41	justin_smith	just pass me the thing that satisfies it and we are good
15:41	AeroNotix	just a value of something which implements the protocol
15:42	justin_smith	exactly!
15:42	muhuk	I don't want the consumer to know anything more than the ns of the backend
15:42	muhuk	(if I can get away with it)
15:43	justin_smith	passing a map from keyword to keyword (said keyword needing -> string -> symbol -> var -> deref translation to be used) is just a very inefficient way of doing the same thing
15:43	AeroNotix	you don't need to know anything about the backend at all
15:43	justin_smith	muhuk: the consumer doesn't need to even know the ns!
15:43	AeroNotix	muhuk: you already know the operations you want to call on that object, right?
15:43	justin_smith	muhuk: if you implement my protocol, all I need to know is the methods I defined for my protocol
15:43	justin_smith	that's it
15:43	justin_smith	nothing else
15:43	AeroNotix	muhuk: look up defprotocol
15:44	justin_smith	(well that plus an instance of a thing that implements it, but how that's done is none of my business as the caller)
15:44	muhuk	justin_smith: see core.clj, suppose I removed that require
15:44	justin_smith	muhuk: the caller only needs to know it's protocol
15:44	justin_smith	muhuk: it can call the protocol methods
15:44	muhuk	justin_smith: and pass the ns as a symbol or keyword to make-world
15:44	justin_smith	the object implementing those methods is known because it is anonymously passed in
15:45	justin_smith	muhuk: why should the caller give a shit about your ns at all? it shouldn't matter
15:45	AeroNotix	muhuk: make a protocol which mandates `make-world` as a function, pass in a value which implements that
15:45	justin_smith	muhuk: the implementor shouldn't even need to implement an ns
15:45	jackhill	I'm having trouble with clooj: I only get a blank window, nothing is drawn in it. Has anyone else seen this?
15:45	muhuk	justin_smith: ok, how does the consumer call make-world and choose a backend then?
15:45	justin_smith	muhuk: it doesn't chose a backend, the end user passes one to it
15:46	muhuk	jackhill: it used to work for me. Any particular reason why you're not using Lighttable?
15:46	justin_smith	and make-world is a part of the implementor's protocol / is the implementor's multimethod, so they know how to call it
15:47	muhuk	justin_smith: I don't want the backend to be imported by consumer. How does that work?
15:47	jackhill	muhuk: I just wanted to try it out, but I suspect something is wrong with my Java setup, so I would like to get that fixed
15:47	muhuk	you guys are inverting my deps
15:47	justin_smith	muhuk: why not? they are creating something that is designed around the back-end's needs
15:47	muhuk	jackhill: probably. Maybe try another GUI app.
15:47	justin_smith	so why shouldn't they import an interface defined by that backend?
15:48	jackhill	muhuk: do you have a suggestion?
15:48	muhuk	jackhill: not really. You can try compiling a minimal swing example maybe.
15:49	muhuk	justin_smith: not really, backends should be interchangeable.
15:49	justin_smith	muhuk: make the backends all use the same protocol
15:49	justin_smith	same idea
15:49	mmitchell	I want to catch exceptions based on their ex-data contents. Any suggestions for how to do this? An existing library perhaps? Also, are there any plans to provide this sort of thing in clojure core?
15:49	justin_smith	the backends all use the same protocol, the frontends pass in an instance of a thing implementing said protocol to the backend
15:50	justin_smith	thus both frontend and backend are fully interchangable
15:50	justin_smith	muhuk: if you really must use magic keys in a map instead of a formal interface, just use {:f x :g y} etc. where x and y are just functions, don't force people to implement special namespaces
15:51	muhuk	justin_smith: I still don't like it if the consumer is calling stuff directly on the backends.
15:51	amalloy	mmitchell: slingshot is basically it, i think. maybe gfredericks has something, called catch-data?
15:51	muhuk	justin_smith: map doesn't do it either.
15:51	mmitchell	oh slingshot right!
15:51	justin_smith	muhuk: the consumer is calling what the implementor explicitly passed to it
15:51	amalloy	yeah, he totally does
15:51	mmitchell	will have a look at catch-data too
15:51	amalloy	i'd try catch-data first
15:51	mmitchell	cool will do
15:51	justin_smith	muhuk: doesn't do what?
15:52	justin_smith	muhuk: are you aware that a namespace is a map from symbols to vars?
15:52	muhuk	justin_smith: I don't know which backends are available, so I can't create a map.
15:52	justin_smith	it's just less flexible because we use it in special ways via require and resolution
15:52	justin_smith	but if you don't need those features, why use an ns?
15:52	justin_smith	muhuk: I think you are being silly
15:53	muhuk	well, you can always move on. It's not a first on IRC.
15:54	justin_smith	muhuk: I wanted to be sure you understood your options, and the extra complexity you are imposing on yourself. If the options are too simple and you prefer the complexity, have at it, hope that's enjoyable to you. No biggie.
15:55	AeroNotix	boom
15:55	mmitchell	+1 on catch-data looks nice and simple. Thanks!
16:00	csd_	- I'm still confused after watching Stuart Sierra's two videos on components, and reading the example code. At some point I think a global var needs to be defined if you're going to let concurrent threads have access to shared state, no?
16:01	csd_	@justin_smith
16:01	dnolen	ClojureScript now support Nashorn based REPL https://github.com/clojure/clojurescript/commit/d0c9451035d3a9adf9a32e16e759d1e4384268dc
16:01	justin_smith	csd_: for shared mutable state you can pass an atom to each component
16:01	amalloy	csd_: no, you can pass those threads whatever state you want without a global
16:01	justin_smith	csd_: it's not global because it could pass a different atom to a different set of components
16:01	justin_smith	what amalloy said
16:02	csd_	would you be able to put in a pastebin a small sketch of what you mean?
16:02	tbaldridge	csd_: if you start and stop a system within a single let you can store the state as a local. I do this all the time when writing tests.
16:03	csd_	if have a local context, create a ref inside it, and then pass the ref to threads, will one thread's mutation of the ref show up in the other threads ?
16:03	justin_smith	absolutely
16:04	justin_smith	wouldn't be much point to refs if it didn't in fact
16:05	csd_	ok seems a bit clearer now
16:07	csd_	so crudely, the better solution would be something like: (let [state (ref {})] (map #(do-stuff state %) [threads]))
16:07	justin_smith	csd_: something with that basic outline, yeah
16:07	csd_	ok
16:08	justin_smith	csd_: advantage being, of course, that testing is now much easier
16:08	justin_smith	if you do it right
16:09	csd_	this is one of those concepts that coming from python etc takes a while to get used to
16:09	amalloy	gfredericks: wait, i remember us talking about the locals-capture feature in catch-data, and you removed it, but i thought you also made throw-data into a function instead of a macro (since it now doesn't have any macro-y features)
16:10	justin_smith	csd_: it's a place where we have options we can articulate, while imperative languages leave only one way to do it for the most part :)
16:11	gfredericks	amalloy: well it does have the macro-y feature of not making noise in your stacktrace
16:11	amalloy	hah. well, fair enough
16:12	gfredericks	I remember talking about that and the other point was that anybody tring to use throw-data not in the call position is a weirdo
16:12	justin_smith	us weirdos get no respect
16:14	amalloy	gfredericks: https://www.refheap.com/d80a9dd79c1374bae013e88a4
16:14	amalloy	all this has happened before, and will happen again
16:14	gfredericks	I look forward to round 3
16:15	amalloy	feature request: add to docstring for throw-data: "macro instead of a function to protect you from yourself, you weirdo"
16:16	gfredericks	patches welcome
16:18	gfredericks	~patches is <reply> welcome
16:18	clojurebot	Roger.
16:18	Glenjamin	what is throw-data from?
16:19	Glenjamin	is throw-data just comp throw ex-info ?
16:19	amalloy	Glenjamin: yes
16:19	gfredericks	github.com/gfredericks/catch-data
16:19	Glenjamin	presumably throw being a macro means that doesn't just work
16:19	gfredericks	throw isn't even a macro but yeah that doesn't work
16:19	Glenjamin	s/macro/special-form
16:20	gfredericks	,(comp throw ex-info)
16:20	clojurebot	#<CompilerException java.lang.RuntimeException: Unable to resolve symbol: throw in this context, compiling:(NO_SOURCE_PATH:0:0)>
16:20	gfredericks	,(let [throw #(throw %)] (comp throw ex-info))
16:20	clojurebot	#<core$comp$fn__4458 clojure.core$comp$fn__4458@3fceb526>
16:20	Glenjamin	makes sense
16:21	gfredericks	I'm going to go add a comment above (defmacro throw-data) to save amalloy some time next time
16:22	amalloy	;; amalloy please stop bothering me, you agreed this should be a macro
16:37	amalloy	so, i have written two different functions in my config-map-munging file that look like (reduce (partial apply assoc) x y), and i can't decide whether it would be more readable or less if i extracted that out into a function. also i don't know what name i would give to (partial reduce (partial apply assoc))
16:37	amalloy	er, assoc-in
16:38	gfredericks	amalloy: this isn't what reduce-kv is for is it?
16:38	amalloy	i'm reducing over a seq, not a map
16:38	amalloy	reducing into a map
16:39	Glenjamin	isn't that (into {}) ?
16:39	amalloy	Glenjamin: yeah if it were actually assoc (like i first said) it would be. but i'm using assoc-in
16:39	Glenjamin	right
16:39	amalloy	on a seq like ([[:x :y] 1] [[:a] 2])
16:40	DerGuteMoritz	how about assoc-into
16:40	amalloy	that's cute
16:40	DerGuteMoritz	hehe
16:41	gfredericks	ininto
16:41	uptown`	is there a lein plugin to profile performance or a way to wrap tests with a profiler to get a sense of how efficient a given form or fn is?
16:42	tcrayford____	uptown`: that's intensely difficult on the JVM
16:42	uptown`	thought so but we live in hope
16:42	tcrayford____	generally I'd recommend using FlightRecorder for profiling, and criterium for benchmarking
16:43	tcrayford____	e.g. the JVM after the JIT has warmed up, will sometimes completely eliminate benchmark code, etc
16:45	tcrayford____	http://docs.oracle.com/javacomponents/jmc-5-4/jfr-runtime-guide/run.htm for flight recorder (assumes you're on an oracle jvm iirc)
16:45	tcrayford____	https://github.com/hugoduncan/criterium for criterium
16:45	tcrayford____	though note you'll want to turn off leiningen's default jvm options - it turns off most of the advanced JIT optimizations
16:46	tcrayford____	(just throw `:jvm-opts ^:replace ["-server"]` in your project.clj, or in a benchmark/profile specific thing)
16:47	tcrayford____	note: I've seen perf differences of 5000x times different because of different benchmarking code, different ordering on benchmark runs etc. It's incredibly difficult to measure perf numbers on the JVM and have them be useful
16:57	uptown`	thanks for the pointer
16:57	uptown`	i'll see if i can get any traction
17:00	tcrayford____	uptown`: sure. I'm giving a talk on clojure and performance at a user group tomorrow, so this has been on my mind a bunch lately :)
17:01	tcrayford____	uptown`: glad I could help :)
17:03	Bronsa	tcrayford____: will you upload slides/notes somewhere? I'd be interested :)
17:03	tcrayford____	Bronsa: I'll (hopefully) post a video somewhere
17:03	Bronsa	ah, that's even better
17:06	justin_smith	tcrayford____: for that 5kx diff, were lazy seqs being forced or not a factor?
17:07	tcrayford____	justin_smith: nope, just reordered benchmarks
17:07	tcrayford____	like
17:08	tcrayford____	(do (bench a) (bench b)) (do (bench b) (bench a)) performs astonishingly differently
17:10	justin_smith	image of the ancient aliens guy, caption: "hotspot"
17:11	tcrayford____	exactly
17:14	uptown`	cries so true
17:24	TimMc	~aot
17:24	clojurebot	aot is Ahead Of Time compilation
17:24	TimMc	~aot
17:24	clojurebot	http://i.qkme.me/3vb225.jpg
17:47	gfredericks	~aot \|was\| so ahead of its time
17:47	clojurebot	In Ordnung
17:50	cfleming	dnolen: pong
17:52	denik	I'm having trouble writing integration tests that depend on channels. For example: I publish 100 messages to rabbitMQ, then, in a go-loop I want to pull each & count to make sure I have 100.
17:53	denik	This is mostly to make sure the go-loop pulls down every message rather than to test rmq
17:54	cfleming	tcrayford____: I'd also be very interested in video/slides/notes to your talk
17:55	dnolen	cfleming: so how do I get Cursive to understand my Clojure Maven project?, also how can I setup a REPL? Do I just need to specify the entire REPL command? Include nrepl?
17:55	dnolen	cfleming: if this is documented somewhere I'm more than happy to read over the setup
17:56	hiredman_	denik: pulling from rabbit mq is blocking io you should not be doing in a go block
17:56	cfleming	dnolen: Not really documented unfortunately. This is about as good as it gets: https://cursiveclojure.com/userguide/projects.html
17:56	denik	horedman: how then?
17:57	denik	hiredman_: I need someway to feed rmq into core.async chans
17:57	cfleming	dnolen: It should just work. You can set up a REPL using the "Use normal process" option instead of "Run with Leiningen". That does assume nREPL is on the classpath, right.
17:58	cfleming	dnolen: That basically starts a Java process with the classpath of the module you select, and starts an nREPL server
17:59	cfleming	dnolen: Actually, I lie - it will automatically add the version of nREPL shipped with Cursive to the classpath.
18:00	cfleming	dnolen: So you should just be able to run it.
18:00	dnolen	cfleming: what Module am I supposed to be selecting? "Java"?
18:01	cfleming	dnolen: Right, you set it up as a Java project
18:01	cfleming	dnolen: But do you already have a Maven project you want to import?
18:01	dnolen	cfleming: yes it's a pre-existing Maven project
18:02	dnolen	cfleming: so I should import it?
18:02	cfleming	dnolen: Ok, then you want File->Import project, Import from external model, Maven, then follow the options
18:13	cfleming	dnolen: Back in a bit - if that doesn't work, let me know the steps you're trying and I'll try to reproduce. I'll update that doc too, since a few people are using Maven now
18:14	dnolen	cfleming: ok so I imported but the same thing always happens for me, nothing is resolveable
18:14	dnolen	cfleming: i.e. the source code
18:14	AeroNotix	Which kafka client do people recommend/
18:14	dnolen	is all highlighted
18:14	AeroNotix	?
18:15	cfleming	dnolen: Has it created source dirs in the right places? Blue folders in the project view?
18:15	AeroNotix	people are using just maven for clojure?
18:15	dnolen	cfleming: blue java folder but not a blue clj one
18:15	dnolen	AeroNotix: yes
18:15	AeroNotix	dnolen: why?
18:15	dnolen	AeroNotix: lots of reasons
18:16	cfleming	AeroNotix: It just works, I guess
18:16	AeroNotix	dnolen: such as?
18:16	dnolen	AeroNotix: I'm not going to enumerate them for you
18:16	AeroNotix	:(
18:16	cfleming	dnolen: If you mark the folder as source, are things resolved correctly? Right click, mark as source
18:16	AeroNotix	I'm genuinely curious what I might be missing out
18:16	AeroNotix	on
18:16	cfleming	dnolen: Sorry, right click, mark directory as, source
18:17	dnolen	cfleming: ok that fixed that thanks!
18:17	amalloy	AeroNotix: better integration with a zillion java tools is one thing, i imagine
18:17	AeroNotix	amalloy: such as the IDEs and things?
18:17	cfleming	dnolen: What you'll find is that that source folder will be removed next time your project is synced
18:17	cfleming	dnolen: You'll have to add something to your POM so that Maven knows that's a source root
18:18	cfleming	dnolen: Whatever the :source-paths Maven equivalent is
18:20	cfleming	dnolen: Actually, check the Clojure project for inspiration, looks like it uses a Clojure Maven plugin to do that
18:20	dnolen	cfleming: hrm REPL interactions don't work
18:20	dnolen	I mean the REPL works
18:20	dnolen	but commands to send stuff to the REPL don't
18:24	dnolen	cfleming: ok got it working, a little weird but this is good enough for me
18:25	cfleming	dnolen: What did you have to change?
18:25	cfleming	dnolen: For the REPL, I mean?
18:26	dnolen	cfleming: I think I had to exclude some directories?
18:27	cfleming	dnolen: That sounds strange - normally it should just require an open active REPL, and to be doing it from a Clojure source file
18:29	dbronico	hey all. i'm new to cljs and am wondering what the idiomatic way to store the response from an xhr call would be in cljs without the callback function being a giant function with all of the program logic.
18:30	dnolen	cfleming: anyways this is good enough for me, after all this time in Cursive for ClojureScript dev now I just want to use it all the time
18:30	dnolen	dbronico: you should look into core.async
18:30	amalloy	cfleming: put dnolen's testimonial on your website somewhere
18:31	raspasov	cfleming: I've always been connecting to a remote REPL (running in a terminal window) and it works great for me; just trying to run a local version to test out the break points etc - I believe it has to run locally right?
18:32	dbronico	dnolen: I actually was, but was a little stuck on how to store. like, do this async thing and put it on the channel, but I can't have below it, (def xhr-response (take! the-chan)), can I?
18:33	raspasov	just trying to make it work with https://github.com/ninjudd/lein-protobuf , for some reason the protocol buffer classes don't get added to the classpath I believe and I get CompilerException java.lang.ClassNotFoundException when try to run locally
18:33	dnolen	dbronico: you can as long as you're in a go block
18:33	raspasov	maybe it doesn't play nicely with the leiningen plugin somehow?
18:33	dbronico	dnolen: oh, ok. and then I can use xhr-response outside of the go block?
18:34	cfleming	dnolen: Great, good to hear :-)
18:34	dnolen	dbronico: by storing it somewhere sure
18:34	cfleming	dnolen: I have a build coming out in the next day or two, hopefully the following one will have CLJS REPLs based on all the new hotness
18:35	dnolen	dbronico: you might want to ask your question in the #clojurescript channel, show us the JS code you would write and someone can show you how to do it better in core.async
18:35	dnolen	cfleming: sweet!
18:35	dbronico	dnolen: oh, ok. i didn't know it had a dedicated chan. thanks!
18:36	cfleming	raspasov: No, you can run it remotely too, but you'll have to create a remote debug connection. Run->Edit Configurations->+->Remote, then start your JVM with the parameters it shows you
18:36	cfleming	raspasov: Connect the remote debugger then the remote REPL, all should work
18:36	raspasov	cfleming: oh great, that's cool, let me try
18:36	cfleming	raspasov: Someone confirmed on the mailing list the other day that that works, let me know if you have problems
18:43	raspasov	cfleming: "Run->Edit Configurations->+->Remote, then start your JVM with the parameters it shows you" - are there special parameters I need to add when running lein repl?
18:45	cfleming	raspasov: Yeah, where it says "Command line arguments for running remote JVM" you need to add those to your JVM startup, in your project.clj
18:46	raspasov	hm I don't see that, could it be because I'm on 13.1 ?
18:50	raspasov	http://i3.minus.com/iXvgpqOA3r2J7.png
19:08	trptcolin	how (if at all) does one get korma (with the postgres jdbc adapter) to tell them how many rows got updated?
19:09	trptcolin	seems like i always get a single record (if any were updated) or an empty seq
19:09	trptcolin	w/ no way to see how many succeeded
19:09	tcrayford____	trptcolin: are you using RETURNING ?
19:10	trptcolin	oh clojure.java.jdbc is all good
19:10	tcrayford____	oh ok :/
19:11	trptcolin	well, "all good" meaning there exists some path where i can get what i want
19:11	trptcolin	yeah... i really like the idea of being able to share pieces of queries, something something composable something
19:12	trptcolin	but every library is frustrating when i'm in the internals trying to figure out a monkeypatch to make it work like i want :)
19:12	{blake}	I tried Korma on Friday, along with Yesql, and I'm using straight JDBC.
19:12	raspasov	ORM = OMG :)
19:13	rhg135	indeed
19:13	tcrayford____	trptcolin: sorry I can't help more :(
19:13	trptcolin	tcrayford____: no worries, thanks for the try :)
19:14	cfleming	raspasov: That's the remote REPL - the config you want is just called "Remote", it's for remote debugging
19:15	cfleming	raspasov: You need two connections to the remote JVM - the debugger and the REPL
19:15	raspasov	cfleming: ah got it, I'm blind
19:15	{blake}	cfleming: As long as you're hanging around...what's the magic for starting the debugger?
19:15	raspasov	/don't follow instructions carefully/ lol
19:16	raspasov	I'm sure cfleming is having a hard time working with all of asking questions :-)
19:16	raspasov	all of us*
19:16	{blake}	I hardly see how we can be held accountable for a lack of adequate cloning technology.
19:18	raspasov	haha well
19:22	AeroNotix	ok what's the deal with lazy-seqs
19:22	AeroNotix	I have found some code which blocks outside of a lazy-seq, but works inside of one
19:22	AeroNotix	"works"
19:22	amalloy	AeroNotix: ?
19:23	AeroNotix	hmm
19:23	AeroNotix	it's 1:21am
19:23	AeroNotix	Should I be doing this....
19:26	noonian	AeroNotix: what do you mean 'works inside' of lazy-seq? if you aren't every realizing the lazy seq it might just never be executing the blocking code
19:26	AeroNotix	noonian: yeah that's what I just realised
19:27	noonian	heh
19:27	AeroNotix	this is inside a library
19:28	noonian	what library/code?
19:28	AeroNotix	clj-kafka
19:30	AeroNotix	I actually can't get it to read messages out of a kafka queue for some reason
19:30	AeroNotix	and the laziness inside the read with clj-kafka covered up something for a while
19:32	TimMc	Ugh, just got bit by http://dev.clojure.org/jira/browse/CLJ-1232
19:32	noonian	sounds frustrating. I have zero experience with kafka so probably can't be much help. If you posted some code snippets someone might notice something funky.
19:32	AeroNotix	noonian: just run of the mill stuff really. Straight out the README.
19:32	TimMc	(defn foo ^Hint [] ...) fails when a.b.Hint is not imported in the namespaces that calls that fn.
19:33	cfleming	raspasov: If it weren't for you people I'd be at version 7 by now, instead of still in beta :)
19:33	AeroNotix	TimMc: :(
19:33	raspasov	cfleming: lol
19:33	cfleming	{blake}: Are you having problems starting the debugger?
19:33	{blake}	cfleming: Yes! Uh...where is it? =P
19:33	cfleming	raspasov: Actually, that's mostly true of my daughter rather than tech support
19:34	cfleming	{blake}: Haha, I see
19:34	raspasov	raspasov: haha well
19:34	raspasov	cfleming: haha well
19:34	cfleming	{blake}: See here under Starting a debug REPL: https://cursiveclojure.com/userguide/repl.html
19:35	cfleming	{blake}: There's no real doc on this at the moment, in the meantime you can try https://confluence.jetbrains.com/display/IntelliJIDEA/Debugger
19:35	cfleming	{blake}: That's Java specific but mostly relevant
19:35	cfleming	There are bugfixes for the debugger in the next build too
19:36	{blake}	cfleming: Oh, okay, cool, I'll give it a shot. I didn't think that would work.
19:36	{blake}	cfleming: When are we going to be able to buy?
19:36	cfleming	{blake}: Yeah - make sure you're on 0.1.44, lots of fixes there
19:36	cfleming	{blake}: Not sure, but the shortlist for a version 1 is getting shorter
19:37	{blake}	cfleming: Cool. Yeah, I'm up-to-date.
19:45	andyf	TimMc: Fortunately clj-1232 has a pretty easy workaround - add import, or edit function to fully qualify the type. I was going to recommend voting, but see you already have
19:46	cfleming	TimMc andyf: The other workaround is to type hint the var, not the args vector
19:47	TimMc	andyf: Easy, but annoying and bloaty. Also, I'm annoyed at Rich for saying it shouldn't be fixed at all.
19:48	cfleming	TimMc: Yeah, I hate that bug.
19:49	cfleming	TimMc: Fortunately type hinting the var works fine, so that's what I do everywhere.
19:49	cfleming	TimMc: With an imported class, I mean.
19:56	TimMc	cfleming: I found if I put a newline after the arity hint it's not so bad -- it increases vertical space use, but at least the giant Java class names don't push the arglist waaaay over.
19:56	cfleming	TimMc: Any reason you don't want to hint the var?
20:00	OldTree	is it possible to use Om's transact function outside of a component?
20:01	amalloy	yeah, hinting the var is the thing you're supposed to do
20:02	amalloy	i basically regard hinting the argvector with a non-primitive type to be an accidental feature and am not terribly surprised when it doesn't work
20:02	hiredman_	which is hilarious, because it used to not work at all, until someone tried to unify the two ways to hint the return type
20:03	cfleming	amalloy: I'd say based on the doc, you're supposed to hint the arg vector, but no-one does because of this bug
20:03	amalloy	what doc?
20:04	cfleming	amalloy: http://clojure.org/java_interop#Java%20Interop-Type%20Hints
20:04	cfleming	"For function return values, the type hint can be placed before the arguments vector:"
20:05	cfleming	The doc for fn and defn make no mention of type hints at all
20:06	cfleming	I guess the only advantage is that you can hint individual arities differently
20:07	cfleming	Although IMO that's probably bad, or at least confusing, form anyway
20:15	gfredericks	dangit I'm writing a little data diff/patch library
20:15	gfredericks	how could this have happened.
20:15	dangit	Are you taking my name in vain?
20:16	gfredericks	no in vein
20:16	gfredericks	also sometimes in vane
20:21	cfleming	I've always wondered who someone is - they must get pinged a lot
20:22	amalloy	hey, speaking of, whatever happened to the guy named so?
20:22	amalloy	$karma so
20:22	lazybot	so has karma -33.
20:29	gfredericks	oh is that why so gets dec'd
20:30	amalloy	gfredericks: yeah, numerous times i heard people complain that he kept making the word "so" get the username-highlight treatment in their clients
20:31	gfredericks	(dec so) ; serves him or her right
20:31	lazybot	⇒ -34
20:40	gfredericks	there we go https://github.com/gfredericks/minus
20:40	gfredericks	now it just needs a decent algorithm or two
20:41	amalloy	ahaha that algorithm. too good
20:42	gfredericks	hey man it works great and anybody can understand it
20:42	amalloy	i was like, wow, what algorithm could be correct but trivial
20:42	amalloy	question answered
20:56	justin_smith	gfredericks: seeing the defmulti for diff, I expected something using data.diff at first
20:57	justin_smith	(inc dangit)
20:57	lazybot	⇒ 1
21:12	gfredericks	justin_smith: well it could but that would be an impl detail
21:27	dnolen	https://github.com/omcljs/om
21:29	julianleviston	Building a thing to run n things in “parallel” using core.async go blocks… but I want the results to be co-ordinated into a set of results and the main body to block until the results are in, at which time it does something contingent on them finishing. This code is currently sitting in a doseq block… is there a nice way to do this? What would you call this? is it fanning? I can only think of doing it via a bunch
21:29	julianleviston	n go blocks, then a blocking loop that takes n values off a “results chan”… is that a good way?
21:37	julianleviston	Maybe I’ll take a stab at that and see what happens.
21:38	justin_smith	between "doing it via a bunch" and "n go blocks" I think your irc client ate something
21:43	julianleviston	I wrote: Building a thing to run n things in “parallel” using core.async go blocks… but I want the results to be co-ordinated into a set of results and the main body to block until the results are in, at which time it does something contingent on them finishing. This code is currently sitting in a doseq block… is there a nice way to do this? What would you call this? is it fanning? I can only think of doing it vi
21:43	julianleviston	bunch of n go blocks, then a blocking loop that takes n values off a “results chan”… is that a good way?
21:43	amalloy	julianleviston: there is a maximum length to the length of an IRC message
21:44	justin_smith	julianleviston: your message is cut off (even eariler this time)
21:44	amalloy	your client doesn't seem to know what it is
21:44	julianleviston	Maybe my expressions capacity got broken
21:44	julianleviston	ah....
21:44	julianleviston	That’s weird.
21:44	julianleviston	lol
21:44	julianleviston	Building a thing to run n things in "parallel" using core.async go blocks, but I want the results to be co-ordinated into a set of results and the main body to block until the results are in,
21:44	julianleviston	at which time it does something contingent on them finishing.
21:45	julianleviston	This code is currently sitting in a doseq block. Is there a nice way to do this? What would you call this? is it fanning?
21:45	julianleviston	I can only think of doing it via a bunch of n go blocks, then a blocking loop that takes n values off "a results chan"... is that a good way?
21:45	julianleviston	Hopefully all that came thru :)
21:45	julianleviston	(it may have been due to strange chars I was typing)
21:46	justin_smith	julianleviston: that idea looks perfectly reasonable (now that I know there is nothing insane hiding in the truncating part)
21:46	julianleviston	haha :)
21:46	julianleviston	ok thanks.
21:46	justin_smith	julianleviston: a function that spawns one of the worker go blocks
21:46	justin_smith	and then a go block that sends your inputs to those channels, and then waits on all of them coming back, perhaps with a timeout or whatever
21:47	justin_smith	that is, function that spawns the worker go blocks, then run it N times etc.
21:50	julianleviston	yep. Just seems a little clunky to write it myself. I kind of assumed there would be prior work... like ?oh, that?s a fanning pattern, just use the fan function from blah blah? or something...
21:51	julianleviston	but I’m halfway done writing it so, all good :)
21:51	justin_smith	julianleviston: oh yeah, that likely exists, I can't name the function though
21:51	justin_smith	haha
21:52	drsco	julianleviston: have you looked at pipeline or pipeline-async?
21:52	julianleviston	drsco: do they work on cljs?
21:53	drsco	yep
21:53	julianleviston	drsco: I did look at them and followed a tute oh them… but I wasn’t sure coz the tute was for clj, not cljs.
21:53	drsco	used pipeline-async yesterday
21:53	julianleviston	drsco: ah ok. cool… that sounds like it’d be helpful...
21:53	julianleviston	I find the dox a bit… terse.
21:53	drsco	yeh, i didn't see that mentioned on the clojure docs either, but i found some docs elsewhere that did mention. lemme see if i can find the link.
21:54	julianleviston	good if you know what they’re talking about...
21:54	drsco	for sure. precise, but hard to puzzle the use case unless you've seen it before.
21:55	julianleviston	drsco: no, not really… I think it’s hard to even see the use case sometimes, even if you’ve had it before...
21:55	drsco	julianleviston: check this http://www.core-async.info/reference/apidocs#pipeline_async
21:56	julianleviston	drsco: until you’ve built it yourself… then you’re like… “oh… this thing here!”
21:56	julianleviston	yeah that site is great!
21:56	drsco	page is slow. painful client side rendering, but nice looking.
21:56	julianleviston	ironically for about 2 weeks I could never get it to load on safari… works fine on chrome tho.
21:56	drsco	i like how it breaks out the clojure and cljs source. very handy.
21:57	drsco	weird. looks like maybe it's polymer or material design type of thing. probably relying on something slightly experimental.
21:57	julianleviston	drsco: isn’t it the same as the main clojure site for core async?
21:57	julianleviston	drsco: I really don’t undrestand what the desc of pipeline-async means. :(
21:57	drsco	the part from the docstring is. no inlined source on clojure docs i don't think.
21:58	julianleviston	drsco: ah ok.
21:58	drsco	hmm...well i think it does what you're asking for. let me see if i can break it down. i'm pretty new to this still.
21:58	julianleviston	drsco: I guess pipeline-async handles the “paralleling
21:58	julianleviston	“paralleling” part...
21:59	julianleviston	and then I’d write a doseq n underneath that blocked the main go block until I had all the results in?
21:59	justin_smith	julianleviston: yeah, it does the fanning out, and then you can then feed it into your own fan in (via the design of the function parallelized)
21:59	julianleviston	got it.
22:00	drsco	right, af is a transducer that runs on the fan in part.
22:00	julianleviston	um…
22:00	julianleviston	it is?
22:01	julianleviston	I’m not confident I can write a transducer, and that’s not what the doc says.
22:01	drsco	it could just be a simple 1-to-1, but it doesn't have to be
22:01	drsco	wait, i'm wrong. my mistake
22:01	julianleviston	I’ve looked quite a bit into transducers, but they’re complex.
22:01	julianleviston	drsco: phew! :)
22:01	julianleviston	ironically it’s complex to understand them because they’re so simple.
22:02	drsco	af is the async function. derp.
22:02	julianleviston	yay! :)
22:02	JustinusIII	does transducers require understanding of reducers?
22:02	drsco	but using them isn't so tricky.
22:02	drsco	http://matthiasnehlsen.com/blog/2014/10/06/Building-Systems-in-Clojure-2/
22:02	julianleviston	drsco: using tranducers is easy. Making them is tricky.
22:02	drsco	i enjoyed that article a lot. nice graphic.
22:02	justin_smith	JustinusIII: not really - transducers are stackable transformations you can put on some source of data
22:03	justin_smith	julianleviston: uhm (filter isafoo?) is a transducer
22:03	justin_smith	julianleviston: or (map frob-it)
22:03	justin_smith	,(type (map even?))
22:03	clojurebot	clojure.core$map$fn__4507
22:03	julianleviston	justin_smith: sorry I mean making a function that creates transducers.
22:03	justin_smith	,(fn [] (map even?))
22:03	clojurebot	#<sandbox$eval49$fn__50 sandbox$eval49$fn__50@799b710e>
22:03	justin_smith	:P
22:04	justin_smith	julianleviston: they may seem weird, but they are not actually super hard
22:04	drsco	and they're composable with comp, stackable as you said
22:04	julianleviston	justin_smith: what do you call functions that create transducers?
22:04	justin_smith	right. They do what I expected eg. nested usage of map to do when I first learned clojure
22:05	justin_smith	,(sequence (comp (filter even?) (map inc)) (range 10))
22:05	clojurebot	(1 3 5 7 9)
22:05	justin_smith	there's a pair of transducers composed and applied to a lazy-seq
22:05	TEttinger	it's weird how comp is in reverse order here
22:05	TEttinger	or not reversed I guess
22:05	justin_smith	TEttinger: middleware style :)
22:06	drsco	yeh, it's mindbending
22:06	drsco	just a little
22:06	julianleviston	justin_smith: yeah, the thing that is hard is creating your own transducer factory.
22:06	justin_smith	julianleviston: when do you need to do that?
22:07	julianleviston	justin_smith: when you want to write map, or something different than the provided ones.
22:07	drsco	julianleviston: take a look at the streaming-buffer example in the link i posted above
22:07	julianleviston	drsco: why?
22:07	drsco	or log-count in the same one, that one is a bit simpler
22:08	justin_smith	OK, but one main point of transducers is not needing to implement eg. map over and over - you just pull in the transducers that have them all defined
22:08	drsco	it describes how to make your own transducing function
22:08	JustinusIII	reducers in Joy Of Clojure 2 was scary....I didn't have the courage to look into transducers after that
22:08	justin_smith	JustinusIII: I think it's much easier when you get to a point where you've done the stuff they abstract over enough times to realize the benefit
22:09	julianleviston	drsco: I’m pretty familiar wth transducer usage.
22:09	julianleviston	drsco: just not the nomenclature...
22:09	drsco	ah, ok, got it.
22:09	julianleviston	drsco: aparently.
22:09	julianleviston	drsco: so map is an example of a transducing function?
22:10	julianleviston	drsco: a “tranducing function” is any function that has a single-arity that produces a transducer, yes?
22:10	drsco	perhaps i'm not using the right nomenclature either. should probably verify.
22:10	justin_smith	julianleviston: if you provide one arg, yes
22:10	JustinusIII	justin_smith: hmmm....what are the best resources to learn transducers?
22:10	justin_smith	julianleviston: the single arg thing isn't a pre-req
22:10	julianleviston	justin_smith: that’s a single arity, is it not?
22:10	julianleviston	justin_smith: ah ok.
22:11	justin_smith	julianleviston: right, but the arg count is an implementation detail is all I am saying
22:11	julianleviston	I think rich hickey’s trandsucer talks are the best. He explains well.
22:11	justin_smith	a transducer with two or three args could exist, as long as it has the right behaviors
22:11	drsco	justin_smith: because map, filter, et al already had two and three arity versions, right?
22:11	justin_smith	I like this talk by Rich Hickey on transducers. Opens with the classic burrito joke. https://www.youtube.com/watch?v=6mTbuzafcII
22:12	justin_smith	drsco: right
22:12	justin_smith	julianleviston: he gives a really nice intro to what the point of transducers is
22:13	justin_smith	julianleviston: even just the first couple minutes is very informative
22:13	julianleviston	justin_smith: it is a great talk. As is the precursor talk...
22:13	julianleviston	I really liked his core async ones, too...
22:13	julianleviston	plus, this page is obviously pretty useful… http://blog.cognitect.com/blog/2014/8/6/transducers-are-coming
22:20	julianleviston	god I can never remember which of <! or >! is which, or which order they go in. GUH
22:21	justin_smith	julianleviston: in a let block, the > or < will point in the direction the data is going
22:21	julianleviston	justin_smith: that makes no sense.
22:21	julianleviston	justin_smith: sorry, but these things always depend on your perspective, and mine isn’t fixed.
22:21	justin_smith	so (let [result (<! c)] ...)
22:21	julianleviston	justin_smith: again… that doesn’t help.
22:21	justin_smith	that means c has contents going into result
22:22	justin_smith	OK
22:22	julianleviston	justin_smith: yeah, I know when I look it up, but what’s to say that it’s pointing to the data, or the channel?
22:22	julianleviston	justin_smith: lol :)
22:22	justin_smith	julianleviston: the arrow points in the direction the data moves
22:22	justin_smith	> means left to right
22:23	justin_smith	< means right to left
22:23	julianleviston	justin_smith: in relation to what, positionally?
22:23	julianleviston	justin_smith: the syntax of clojure?
22:23	justin_smith	the thing that gets the data, and the thing that sends it
22:23	justin_smith	right
22:23	rerb	Newbie alert. I want to swap a couple of values in a vector. What's the idiomatic way of going from, e.g., [1 2 3 4] to [1 3 2 4]?
22:23	julianleviston	ok… so !> chan is put?
22:23	justin_smith	the binding in the let block will be to the left of the (<! call)
22:23	justin_smith	right
22:23	gfredericks	rerb: an assoc call
22:24	justin_smith	because the place the data is going is to the right of >!
22:24	gfredericks	(defn swap [m k1 k2] (assoc m k1 (get m k2) k2 (get m k1)))
22:24	julianleviston	so <! means takne?
22:24	amalloy	!> doesn't exist, it's >!
22:24	julianleviston	take*
22:24	justin_smith	julianleviston: right
22:24	julianleviston	gfredericks: don’t def swap!
22:24	gfredericks	okay
22:25	julianleviston	gfredericks: IMHO.
22:25	rerb	gfredericks - thanks
22:25	gfredericks	np
22:25	julianleviston	amalloy: see my problem? lol
22:25	julianleviston	it’s fine… just annoying
22:25	amalloy	shrug everyone has to figure out their own mnemonics
22:25	julianleviston	amalloy: exactly. That’s the problem.
22:25	gfredericks	we need to standardize on mnemonics
22:25	amalloy	how do you keep + and * straight?
22:25	julianleviston	amalloy: I’ve never once had to look up put or take tho...
22:26	amalloy	they're both crossy mathy things
22:26	gfredericks	(inc amalloy)
22:26	julianleviston	amalloy: it’s not quite the same, actually…
22:26	lazybot	⇒ 220
22:26	amalloy	both make numbers bigger
22:26	julianleviston	amalloy: - and + would be a better example/
22:26	julianleviston	amalloy: and the’re clearly different.
22:26	TEttinger	yeah, and I always mess up my addition and tetration operators
22:26	justin_smith	amalloy: or even > and < in a math context :)
22:26	julianleviston	+ has more strokes than -
22:27	gfredericks	I'm always confusing unchecked-byte with alter-var-root
22:27	julianleviston	justin_smith: > and < is a better example. the big part is linguistically on the left… we say “5 is greater than 3”
22:27	julianleviston	lol… ok maybe I’m being a douche… point taken.
22:27	amalloy	julianleviston: justin_smith was trying to give you an analogous mnemonic
22:28	amalloy	but instead of stopping to think about it you immediately reponded "that makes no sense"
22:28	julianleviston	amalloy: I value his help, and what I was annoyed about wasn’t him.
22:28	julianleviston	amalloy: I have thought about it a fair bit, actually :) I’m not flaming at the moment.
22:29	justin_smith	julianleviston: in general, in data-flow or related types of frameworks, you often see some kind of "arrow" as an operator that indicates which direction your data is flowing in a given statement
22:29	justin_smith	> and < are popular constituent characters for "flow of data" arrows
22:30	TimMc	cfleming: Hinting the var with a classname looks icky. :-P (It makes it a little harder to read.)
22:30	julianleviston	justin_smith: yeah, I know this. I’m not debating the logic of using it. I just generally expect Rich to make saner decisions than “the majority did it that way”.
22:30	justin_smith	OK
22:30	julianleviston	at the end of the day it doesn’t matter, tho… I’ll just be quiet. It’s just syntax.
22:31	julianleviston	Oh… the pling is the pling of “whatchout”?
22:31	justin_smith	general question: would people hate you for remapping <! and >! to more verbose names in your code?
22:31	justin_smith	julianleviston: the bang? yeah
22:31	julianleviston	justin_smith: It’s cool… I want to use the condoned names. Thanks for being so supportive… :)
22:31	TimMc	_GT__BANG_ is a good choice
22:31	julianleviston	justin_smith: revelation!
22:31	TimMc	but not for both
22:31	TimMc	hmmm
22:31	justin_smith	(inc TimMc)
22:31	lazybot	⇒ 89
22:31	julianleviston	lol
22:31	TimMc	I have karma for the stupidest things.
22:32	julianleviston	(inc TimMc)
22:32	lazybot	⇒ 90
22:32	TimMc	amalloy has karma for actually helping people
22:32	justin_smith	I've likely got an even mix
22:32	julianleviston	(dec julianleviston )
22:32	lazybot	⇒ -1
22:33	julianleviston	clojureland is so pretty :) <3
22:33	amalloy	i like to imagine that the ! is the channel
22:33	justin_smith	oh, nice :)
22:33	amalloy	stuff being pushed into it, squeezed out of it, via the <>
22:34	julianleviston	amalloy: yeah, I used to do that, too… then I forgot which side it went on. LOL. But now I undrestand it’s the bang of danger, I can always know.
22:38	julianleviston	drsco: thanks for the help, the async fanning worked nicely. I should probably rewrite it to use pipeline now tho… because I have unlimited width… which is not good. I like the pipeline fn which requires a parallelism argument… mine just fans infinitely.
22:40	raspasov_	julianleviston: are you using core async pipelines?
22:40	julianleviston	raspasov_: I’m about ti.
22:40	julianleviston	to*
22:41	raspasov_	Cool I use them as well
22:41	raspasov_	Pretty good, you know about the pipeline vs pipeline-blocking?
22:41	julianleviston	raspasov_: not really… do tell :)
22:41	julianleviston	raspasov_: the doc says “same but blocking” lol :)
22:42	raspasov_	Depending on the type of operations you are going to do
22:42	raspasov_	If there's going to be blocking IO calls basically use blocking otherwise you are going to exhaust the limited core async thread pool potentially fast
22:43	justin_smith	amalloy: gfredericks: thanks for the laugh
22:43	amalloy	you're welcome
22:43	amalloy	i think if obtainance were a word it would quickly degrade to obtenance, so i can't advocate that choice
22:44	julianleviston	raspasov_: the work I’m doing is caching some data…
22:45	gfredericks	catch-data!
22:45	julianleviston	lol.
22:45	raspasov_	Caching data in memory?
22:45	raspasov_	On the same machine?
22:45	julianleviston	raspasov_: yissir!
22:45	julianleviston	raspasov_: in cljs, tho.
22:46	raspasov_	Oh
22:46	raspasov_	I'm pretty sure there's no blocking there
22:46	julianleviston	raspasov_: yeah, no core.cache for me.
22:46	raspasov_	It's only one thread
22:46	julianleviston	raspasov_: yeah.
22:47	julianleviston	it’s only a tiny memoizationy kind of cache anyway.
22:47	raspasov_	Ok well I don't even know if you really get any benefit from pipelining on cljs?
22:47	julianleviston	raspasov_: just wanted to make sure I didn’t do it in sequence too much or it takes too ages.
22:47	julianleviston	raspasov_: I don’t either! :)
22:48	raspasov_	Yea you should benchmark with and without
22:48	julianleviston	raspasov_: I’m experimenting… but it seems to be faster with my fanning in place…
22:48	julianleviston	raspasov_: at this stage I’d be happy if my UI didn’t block.
22:48	raspasov_	Yea I have no experience with pipeline on cljs
22:49	raspasov_	That's always good to avoid ! :)
22:49	raspasov_	You building a web app?
22:50	Lewix	hello all
22:51	Lewix	https://gist.github.com/6ewis/f86d3c0721e79197712c - please some insight
22:51	drsco	julianleviston: glad to hear it's working out
22:51	julianleviston	raspasov_: yeah, a really difficult one.
22:51	julianleviston	raspasov_: Well, for me… seeing as it has been my first clojure app…
22:51	julianleviston	raspasov_: rewriting it from Ember.
22:51	raspasov_	Difficult = learning = good ;)
22:51	julianleviston	raspasov_: indeed!
22:51	raspasov_	Even better lol!
22:52	Lewix	julianleviston: how do you like it. Im new too
22:52	justin_smith	Lewix: can you explain what you think ` is for?
22:52	julianleviston	Lewix: I’m not that new…
22:52	Lewix	justin_smith: changing it to the data structure list
22:52	justin_smith	Lewix: it being...
22:52	julianleviston	Lewix: about 7 months into clojure… more or less...
22:53	Lewix	justin_smith: I see. It's only me myself and i then..sniff
22:53	julianleviston	Lewix: lol how new are you?
22:53	justin_smith	Lewix: the problem here is that (1 2 3 4) is evaluated before your function is run
22:53	justin_smith	Lewix: if you want to be able to provide a list in that way, second would need to be a macro
22:54	Lewix	julianleviston: two days ago new
22:54	julianleviston	Lewix: wow… that is new.
22:54	julianleviston	Lewix: is CLJ your first lisp?
22:54	TEttinger	` is the syntax-quote, and it's not meant for newbies. I've used clojure for at least 2 years now, off and on, and I have never used it
22:54	julianleviston	Lewix: just FYI, on your gist, you should probably mention your expected output, too...
22:54	justin_smith	Lewix: functions get their args evaluated before they are called, macros get access to the raw form of the provided arguments, and can modify them before they are evaluated
22:54	Lewix	justin_smith: so it doesnt expect it as arg
22:55	justin_smith	Lewix: can you rephrase that?
22:55	Lewix	justin_smith: sorry
22:55	julianleviston	Lewix: yeah, what are you trying to do?
22:55	julianleviston	raspasov: mmm
22:56	julianleviston	raspasov: Using Om.
22:56	Lewix	justin_smith: so if i have a function fn and arg [arg], it expect a data structure right?
22:56	Lewix	and ( 1 2 3 4) is not a pure list
22:56	justin_smith	Lewix: the function doesn't get to decide how its args are evaluated
22:57	justin_smith	in clojure source code, (f) means invoke f (except for a few very specific contexts)
22:57	julianleviston	Lewix: maybe you mean to write ‘list not `list
22:57	TEttinger	julianleviston, wrong quote
22:57	TEttinger	,(defn snd [coll] (nth coll 1))
22:57	clojurebot	#'sandbox/snd
22:57	justin_smith	,(+ 1 (+ 2 3)) ; in this case, (+ 2 3) is not passed to the top level +, it is evaluated to 5 first
22:57	clojurebot	6
22:57	TEttinger	,(snd '(0 1 2 3))
22:57	clojurebot	1
22:57	julianleviston	tho that wouldn’t work very well...
22:58	julianleviston	Lewix: it’d be good to know what you’re trying to do.
22:58	Lewix	julianleviston: i thought my gist was informative enough
22:58	Lewix	if you read the comments
22:58	justin_smith	Lewix: in order to change the rules for evaluation, you need to use a macro
22:58	TEttinger	(doc second)
22:58	clojurebot	"([x]); Same as (first (next x))"
22:58	julianleviston	Lewix: your gist just says it doesn’t work.
22:59	justin_smith	Lewix: and making (1 2 3) mean '(1 2 3) means changing evaluation rules
22:59	TEttinger	I think you should not start with macros
22:59	TEttinger	start with 4clojure maybe
22:59	justin_smith	agreed
22:59	TEttinger	$google 4clojure
22:59	lazybot	[4clojure – Welcome!] https://www.4clojure.com/
22:59	julianleviston	(second (1 2 3 4)) isn’t valid syntax… because (1 2 3 4) means “run the function called 1 with the arduments 2 3 4)
23:00	Lewix	julianleviston: what i thought. thanks
23:00	Lewix	justin_smith: thank you
23:00	TEttinger	also, [] is strongly preferred for list-like data instead of '()
23:00	Lewix	TEttinger: isnt [] vectors
23:00	TEttinger	yes
23:00	justin_smith	Lewix: np
23:00	TEttinger	they're extremely similar
23:00	julianleviston	Lewix: which brings me back to my question… what are you trying to do?
23:00	Lewix	julianleviston: learning
23:00	Lewix	simple
23:00	TEttinger	vectors however don't quote their insides
23:00	justin_smith	Lewix: most of clojure is defined in terms of interfaces, not concrete classes, so it is quite rare that you actually need a list rather than a vector
23:01	Lewix	justin_smith: i see - thanks. i have a long way to go
23:01	justin_smith	Lewix: if you repeatedly add items to the front, yes you want an actual list, otherwise using a vector loses nothing
23:01	julianleviston	Lewix: in that case, all lists that are being used as data must be quoted, or they will be evaluated as function calls…
23:01	Lewix	thanks guys
23:01	Lewix	back to playing with some code
23:02	julianleviston	Lewix: you might want to look into defn next. :)
23:02	TEttinger	map filter reduce are all important, and you'll get to them quickly I hope
23:03	justin_smith	Lewix: actually, now that I think about it "list the functions that work on a list but break when supplied a vector" would be a fun clojure trivia question
23:04	justin_smith	Lewix: I think the answer is very close to 0 if it isn't 0
23:04	justin_smith	any suggestions? I can't think of any...
23:05	TEttinger	map, filter, reduce, and a few others are kinda the building blocks of most other functions in clojure. they're where clojure starts to have a massive edge over java in succinctness of code beyond just "no java boilerplate"
23:05	justin_smith	(in clojure.core that is)
23:05	justin_smith	TEttinger: yup, and all of those seamlessly turn a vector into a seq if needed
23:08	TEttinger	,(eval (list + 1 2))
23:08	clojurebot	#<ExceptionInInitializerError java.lang.ExceptionInInitializerError>
23:08	TEttinger	uh....
23:08	TEttinger	,(eval '(+ 1 2))
23:08	justin_smith	TEttinger: security restrictions :P
23:08	clojurebot	3
23:08	TEttinger	nope
23:08	justin_smith	oh, wow
23:08	TEttinger	,(eval [+ 1 2])
23:08	clojurebot	#<ExceptionInInitializerError java.lang.ExceptionInInitializerError>
23:08	justin_smith	,(eval [+ 1 2])
23:08	clojurebot	#<ExceptionInInitializerError java.lang.ExceptionInInitializerError>
23:08	justin_smith	wat
23:09	TEttinger	needs quoted
23:09	TEttinger	eval
23:09	TEttinger	,(eval '[+ 1 2])
23:09	justin_smith	,(eval (seq [+ 1 2]))
23:09	clojurebot	[#<core$_PLUS_ clojure.core$_PLUS_@2e18648a> 1 2]
23:09	clojurebot	#<ExceptionInInitializerError java.lang.ExceptionInInitializerError>
23:09	justin_smith	wurt
23:09	justin_smith	OK
23:09	justin_smith	,(eval (seq '[+ 1 2]))
23:09	clojurebot	3
23:09	justin_smith	:P
23:10	TEttinger	hiredman_ is the boss, lazybot can't eval
23:10	justin_smith	TEttinger: anyway, point taken - eval definitely behaves very differently when supplied a vector :)
23:10	TEttinger	lol
23:10	TEttinger	I had to rack my brain on that one
23:11	TEttinger	I was thinking, peek/pop?
23:11	justin_smith	oh yeah, that changes in behavior too
23:11	justin_smith	so we have eval, peek, pop
23:11	TEttinger	but it's documented
23:11	justin_smith	and of course conj
23:11	justin_smith	yeah
23:11	julianleviston	but we weren’t talking about behaviour.
23:11	julianleviston	list the functions that work on a list but break when supplied a vector
23:11	justin_smith	ahh, yeah, the code doesn't break
23:11	julianleviston	;-)
23:12	justin_smith	it just does something different :)
23:12	justin_smith	(inc julianleviston)
23:12	lazybot	⇒ 1
23:12	TEttinger	yay karma
23:12	justin_smith	for the technical save
23:12	julianleviston	lol
23:12	julianleviston	(julianleviston)
23:13	julianleviston	I can’t call myself :(
23:13	TEttinger	(identity julianleviston)
23:13	lazybot	julianleviston has karma 1.
23:13	TEttinger	(identity justin_smith)
23:13	lazybot	justin_smith has karma 179.
23:13	julianleviston	(map identity [justin_smith julianleviston])
23:13	julianleviston	(help)
23:14	julianleviston	lol. sorry everyone.
23:14	justin_smith	haha
23:14	TEttinger	it is just a little bot quirk. it doesn't eval it
23:14	justin_smith	((juxt inc dec) julianleviston)
23:14	TEttinger	it's like justin_smith++ in C++ channels
23:14	justin_smith	I like (juxt inc dec) for bad puns - it leaves karma unchanged just as you would expect
23:15	julianleviston	TEttinger: today is the first day I was exposed to this ;)
23:16	TEttinger	here's a good evil C obfuscation: [18:46;31] <jdaywin> for (int c = 10; c--; c >= -10) { } // will stop after 0, of course, not -9, but at a glance not everyone will notice
23:17	julianleviston	TEttinger: oh that’s quite cool… it took me 20 seconds to work out!
23:18	TEttinger	heh, it was after he brought up that any loop that needs to stop before 0 can be done without all 3 forms: for (int c = 10; --c;) { }
23:19	TEttinger	or after 0 with c--
23:19	justin_smith	oh wow that is evil
23:19	justin_smith	(it's been a while since I touched C)
23:19	TEttinger	yes, I'm glad I don't use much of that kind of iteration these days
23:20	TEttinger	you can write some crazy for loop one-liners though
23:20	raspasov_	Wait why does that stop lol?
23:20	justin_smith	gfredericks: I think one could turn this into a slide in a talk about boxing of primitives in clojure http://i.imgur.com/R89vgJB.jpg
23:20	julianleviston	raspasov: the last two segments are out of order.
23:21	julianleviston	c - - will get to 0… which is the condition clause.
23:21	raspasov_	Oh shit lol
23:21	TEttinger	raspasov: the condition is c--, and 0 is falsy in C
23:21	julianleviston	raspasov: and 0 is logical false in c.
23:21	raspasov_	Got it :)
23:21	julianleviston	TEttinger: much succincter! ;-)
23:21	TEttinger	lol
23:21	raspasov_	I guess even in PHP that would "work" lol
23:22	raspasov_	Java?
23:22	julianleviston	TEttinger: (intentional abuse of the English language intended).
23:22	TEttinger	that's adorable, justin_smith
23:22	justin_smith	it could also be used as a set theory intro, if you replaced the equation
23:22	julianleviston	oh my god. it IS.
23:22	julianleviston	that’s so cool
23:23	justin_smith	,#{:cat #{:cat}}
23:23	clojurebot	#{:cat #{:cat}}
23:23	gfredericks	justin_smith: but it's so obviously about cons cells
23:23	justin_smith	aha
23:23	justin_smith	gfredericks: just needs something about "taking the tail" maybe "holding onto the head"
23:24	justin_smith	so if we take the tail of (cons cat (cons cat nil)) it will freak out and swat the other cat...
23:24	gfredericks	for some reason I've never put internet photos in any of my slides
23:25	julianleviston	gfredericks: coincidentally, I’ve never slid on any photos of the internet.
23:26	gfredericks	(inc julianleviston)
23:26	lazybot	⇒ 2
23:27	gfredericks	omg
23:27	gfredericks	somebody help me out
23:27	gfredericks	(first (range)) ;; => 0
23:27	gfredericks	(second (range)) ;; => 1
23:27	gfredericks	(with-redefs [first second] (first (range))) ;; hangs
23:28	justin_smith	$source second
23:28	lazybot	second is http://is.gd/9vPOzT
23:28	gfredericks	oh hah of course
23:28	gfredericks	that's the best
23:28	justin_smith	it becomes an infinite loop
23:28	gfredericks	(inc justin_smith)
23:28	lazybot	⇒ 180
23:29	raspasov_	gfredericks: why are you redefing first to be second? :D
23:29	julianleviston	raspasov: I’m guessing it’s for the lols.
23:29	raspasov_	Lol
23:29	justin_smith	gfredericks is a madman
23:30	rhg135	#define 1 0
23:30	SegFaultAX	Is that analogous to do `True, False = False, True` in Python? :)
23:31	gfredericks	raspasov_: it's only temporary
23:31	julianleviston	coz we have the immutability on our side… ironically.
23:32	rhg135	I'm afraid people actually do this stuff
23:33	justin_smith	it's humor, kind of like using 1nth or 3nd in normal text
23:36	justin_smith	or that story from the cyberiad about the machine that can make anything starting with the letter n