#clojure – 2016-03-08

2016-03-08

00:51	AndreasO	(Select root [:#tag]) seesaw. How do I address the root widget?
01:03	TEttinger	AndreasO: I seem to remember a method that goes up in the hierarchy... let me check
01:04	TEttinger	http://daveray.github.io/seesaw/seesaw.core-api.html#seesaw.core/to-root
01:13	AndreasO	TEttinger: I think that function returns the root of the widget that triggers the event. In my case a button is pushed and triggers an action that should paint a canvas.
01:15	TEttinger	to-root takes a widget as an argument, you could pass it the event-triggering widget or another widget in a different frame/window
01:15	AndreasO	TEttinger: can I pass a tag?
01:16	TEttinger	you could select one first I think
01:16	TEttinger	do you not have the root to pass to select, so you can't use the tag for that reason?
01:30	AndreasO	TEttinger: I'm not sure what count as the root.
01:30	AndreasO	I'll bin the codefinger
01:32	AndreasO	TEttinger: pastebin.com/E63QbV7C
01:33	AndreasO	TEttinger: line 11-13 and 60-68
01:33	AndreasO	Damn. Pastebin not codefinger
01:33	TEttinger	hm, well Draw shouldn't be capitalized
01:37	AndreasO	I've been banging my head for days. I made simple GUIs before, this is somwath more complicated.
01:39	TEttinger	ohhh
01:39	TEttinger	this looks oddly familiar
01:39	TEttinger	I seem to recall a swing thread thing that the demos used
01:40	TEttinger	see the thing with invoke-later ? https://github.com/daveray/seesaw#tldr
01:42	AndreasO	I found a nother mistake now, draw needs one more arg... g2d?
01:46	TEttinger	seems to be a Graphics2D, doesn't look like that section is meant to be used often
01:48	TEttinger	https://github.com/daveray/seesaw/blob/master/test/seesaw/test/examples/clock.clj uses it
01:51	AndreasO	I'll try that.
01:51	TEttinger	it seems to be a :paint related thing
01:51	AndreasO	I might be overthinking this.
01:52	TEttinger	so you can call g2d-taking methods when you're in a fn that is called as a callback from :paint
01:52	TEttinger	since :paint gives the current g2d with it
01:53	AndreasO	Okay
01:53	TEttinger	also the require statement at the top seems weird, two slashes is not normally what I see
01:54	TEttinger	it may be because it isn't used yet that it isn't causing trouble
01:55	AndreasO	You mean the photomath?
01:56	TEttinger	YEAH
01:56	TEttinger	yeah
01:58	AndreasO	Well that's my own lib. It worked well in a nother test I did.
02:02	AndreasO	I'll look into the clock example, hopefully I'll get it. :-)
02:02	TEttinger	hm, not sure where the / is appropriate in those require sections
02:02	TEttinger	it's the part at the bottom
02:03	TEttinger	(canvas :id :canvas :background "#BBBBBB" :paint paint-clock)
02:03	TEttinger	paint-clock is called with a g2d as one of its args
02:04	AndreasO	Thanks!
02:05	TEttinger	I'm not sure how to explain the root thing other than "I tried a bunch of stuff and found some stuff that worked"
02:06	TEttinger	one of the things I did that I don't know if it's recommended is to, instead of using def to immediately create a widget, use defn to make a fn I can call when everything's ready and only then make the widget
02:08	AndreasO	I see, seems a redesign is in order.
02:10	AndreasO	(run :dispose)?
02:17	AndreasO	TEttinger: still there?
02:22	TEttinger	yeah
02:22	TEttinger	it does seem like it needs some moving around
02:22	TEttinger	graphics-related stuff needs to essentially modify a canvas or something like it... I think....
02:23	AndreasO	I se an error. Yes, you can :paint at the moment of creation as in the clock example. But to change it after creation you need to use the config! Command.
02:24	TEttinger	hm?
02:25	TEttinger	:paint is given a fn, it calls it whenever it repaints
02:25	TEttinger	I don't think config! would help here since it would just change the fn but not tell it to use it
02:27	AndreasO	Hmm... I see. Maybe I can put values in a vector that the :paint function reads .
02:29	AndreasO	The lines and dots need to bee saved anyway.
02:29	TEttinger	makes sense, I think
02:29	TEttinger	if they change you might want them in an atom, or you might want to pass them into the next update somehow
02:32	AndreasO	I did something similar in Python. APOS80
02:33	AndreasO	GitHub.com/APOS80/GeoCad
02:34	AndreasO	Some things is made to be mutable.:-)
02:47	AndreasO	TEttinger: thank you!!! I have now painted a circle!!
02:48	TEttinger	woohoo!
02:49	TEttinger	yeah, the examples for seesaw were the most valuable resource I had trying to learn it
02:49	TEttinger	I did make some tiny things early on, it's good for a lot of stuff. One I'm proud of was a nutrition DB searcher for my grandma
02:50	TEttinger	she had bizarre nutrition constraints, like couldn't have much phosphorus, and that isn't on most labels
02:51	AndreasO	For some reason I always try things that don't work instead of doing it right in the first place.
02:51	TEttinger	GUI is much better for grandma than CLI, haha
02:51	AndreasO	I like cli, but a cad in cli?? Nono
02:51	p_l	AndreasO: ever seen AutoCAD?
02:52	AndreasO	I use topical at work
02:52	p_l	or BRL-CAD (which is even more CLI-oriented)
02:52	amalloy	ed \| cad
02:52	AndreasO	Topocad
02:53	p_l	also, OpenSCAD seems to be currently popular thingy on the lower end
02:53	AndreasO	Hmmm... What graphical lib is used for cli?
02:53	p_l	Cadence CAD tools aren't CLI oriented, but IIRC include Lisp REPL :)
02:54	TEttinger	OpenSCAD is good
02:54	p_l	AndreasO: depends on environment - a CAD can have CLI despite being very graphical (the interaction might be through CLI)
02:55	p_l	https://en.wikipedia.org/wiki/OpenSCAD#/media/File:Openscad_screen_english.png <--- example from openscad
02:55	p_l	https://upload.wikimedia.org/wikipedia/commons/e/eb/BRL-CAD_screenshot.jpeg <--- upper left corner has the main editor interface, iirc
02:56	p_l	AndreasO: quite possibly lots of old CAD tools worked well in xterm thanks to its vector graphics support, too :)
02:59	AndreasO	True, but isn't a little more complicated?
02:59	p_l	AndreasO: not necessarily. And can be a godsend when you need to manipulate precisely
03:00	p_l	AutoCAD had very good interface in this which coupled command line with mouse/tablet
03:01	p_l	for example, how easy it is to convey by mouse that you want exactly X milimeters?
03:02	AndreasO	Isn't autocad written in lisp?
03:02	AndreasO	Heard that
03:02	p_l	and most of those CAD programs are directly extensible (AutoCAD with AutoLisp, Cadence stuff in SKILL - a lisp dialect, etc)
03:02	p_l	AndreasO: it isn't
03:02	p_l	it has a very old-school lisp dialect however
03:03	AndreasO	Like scheme?
03:03	p_l	used for interaction and automation (though, similarly to AutoCAD REPL, had been pushed to wayside)
03:03	p_l	AndreasO: Scheme is very modern lisp dialect :D
03:03	p_l	AutoLISP is old style, really old
03:04	p_l	older than elisp by now, because elisp evolved
03:04	p_l	last time I checked, AutoLISP still didn't have lexical scope
03:16	AndreasO	I'm new to lisp, I like it.
05:28	spba	Has anyone here worked through HtDP?
05:32	ridcully	is it "safe" to have a fn and an aliased ns with the same name. e.g. defn json and cheshire :as json - seems to work as expected in the repl, but maybe this is foolish?
05:43	hyPiRion	ridcully: should be safe, yes
05:44	amalloy	ridcully: yes, it's intended to work fine. you can always distinguish from context whether a namespace is meant or a var
05:45	ridcully	hyPiRion, amalloy: thanks. i thought it would since str is often used for clojure.string - but i was never sure, if that would shadow (str)
06:16	clgv	Hello, in Cursive is there something similar to CTRL+W that extends the selection to the next complete s-expr on the left or on the right?
06:25	Empperi	clgv: check Edit -> Structural Editing
06:25	Empperi	you can bind those to any shortcuts you wish
06:26	clgv	Empperi: sure, but which one is it`
06:26	Empperi	well, I don't know what "CTRL+W" is so :)
06:28	clgv	"extend selection to the next full s-expression" is what I am looking for
06:29	clgv	"CTRL+W" is "extend selection" which will select all expressions with an s-expression, then the whole s-expression and so on
06:29	Empperi	hmm, still not sure what that means, so you want to extend selection so that it contains a full s-expression? Yeah, there is that. But it's not in Cursive but in Idea and it works everywhere
06:30	Empperi	ah yeah, it's that then
06:30	Empperi	it's in Idea itself
06:30	Empperi	search for "shrink selection" and "extend selection" in keymap bindings
06:30	Empperi	and it will work in every editor
06:30	clgv	I want (->> xs \|(map bla)\| (map blubb)) to (->> xs \|(map bla) (map blubb)\|) where the selected part is enclosed in \| \|
06:31	Empperi	ok, that's not then exactly the same thing :)
06:31	clgv	I am used to that from CCW ;)
06:32	Empperi	shrink/grow would grow from \|(map bla)\| to both left and right
06:33	Empperi	dunno if there's a selection functionality exactly for that
06:33	Empperi	cfleming will know if anyone knows :)
06:33	clgv	is there bugtracker for cursive?
06:36	ridcully	clgv: i used https://github.com/cursive-ide/cursive/issues the last time - still seems active
06:38	clgv	ridcully: ok, thanks
06:38	Empperi	yeah, that is the place
06:38	Empperi	Cursive itself isn't opensource
06:39	clgv	btw is (.-some_field some-deftype-instance) preferred over (.some-field some-deftype-instance) for field access on deftypes?
06:39	clgv	Cursive tries to convince me strongly
07:04	Empperi	well, deftypes compile to java classes
07:04	Empperi	and you can't name java fields into private Foo some-field;
07:05	Empperi	it's a syntax error
07:05	Empperi	sure they don't compile to java source code but same rules apply on bytecode level
07:05	Empperi	more or less
07:05	Empperi	so yeah, I'd say it's better to stick with those conventions
07:06	Empperi	not sure actually how that will work on bytecode, it just might work
07:06	Empperi	field names with - in them that is
07:06	Empperi	but if you try to access those from java code...
07:07	Empperi	so at least for the sake of java interop you should avoid those
07:23	irctc	Hello, please forgive me just jumping into a question, my ignorance and the assumption that Datomic questions are relevant here. I think I understand queries across history in Datomic. What I'm unsure of is can one create a branch in that history and continue adding data? Can one create a tree of db states or can db history be linear only?
07:36	Empperi	irctc: https://groups.google.com/d/msg/datomic/jYjWvut3v3E/GZeod3hYaRQJ
07:36	Empperi	from 2012 but I guess that's still correct
07:37	Empperi	however this seems to indicate that branching is currently supported http://vvvvalvalval.github.io/posts/2016-01-03-architecture-datomic-branching-reality.html
07:38	Empperi	much less official source though but also much more recent
07:43	hyPiRion	irctc: you also have the notion of sagas, which is explained at the later parts of the presentation named "understanding and using reified transactions" over at http://www.datomic.com/videos.html
07:44	hyPiRion	(I think that's what they're sort-of used for?)
07:46	justin_smith	TEttinger3: regarding ATS and the benchmarks game - the ATS that wins is idiomatic ATS and is not calling assembly libs - it's a low level language with very strong typing. It's a hard language to learn though. Imagine Haskell where gc is explicit instead of implicit.
07:46	justin_smith	also it uses the type system to ensure correctness of resource usage (mem used but not provably freed, or files opened but not provably closed, are type errors)
08:10	clgv	Empperi: yes you can name them like that - Clojure takes care of that
08:10	irctc_	Great, thanks for the resources regarding branching and Datomic!
08:11	clgv	Empperi: I was just asking whether the preferred field access syntax in Clojure changed when they introduce the .- syntax which is compatible with ClojureScript
08:13	Empperi	no idea
08:16	Kah0ona	Quick question; i'm using compojure-api, and for one route I want to stream back a file rather than JSON data.
08:16	Kah0ona	what is the recommended way for setting up such a route, should it use compojure-api at all?
08:16	Kah0ona	or should i drop down to native compojure routes?
08:27	Empperi	well, no point in defining the return type then
08:27	Empperi	you can use compojure-api
08:27	Empperi	just don't define return schema
08:27	Kah0ona	ah so not defining it as s/Any then? :-)
08:27	Kah0ona	thanks
08:28	Empperi	we have it like that without :return and works nice
08:28	Kah0ona	cool will try
08:28	Empperi	then you have to handle response building yourself but that's what you want in that case
08:28	Empperi	actually we stream data through our app from another app of ours straight to browser
08:28	Empperi	it never sits in memory on our servers since we just use InputStreams all the way
08:36	Kah0ona	yeah i'm planning to do the same, when generating PDFs for instance, don't want them to hit the disk
08:41	Empperi	yeah, we are actually serving PDFs too
08:41	Empperi	some of them are HUGE
08:41	Kah0ona	great this works neat :-)
08:41	Kah0ona	neatly*
08:42	Empperi	yeah, it's nice that you can just throw InputStream for ring and it handles it correctly
08:42	Kah0ona	yeah
08:42	Kah0ona	I used to have pretty ugly servlets 'back' in the java days :-)
08:42	Kah0ona	this is really elegant
08:42	Kah0ona	<3
08:46	Empperi	servlets were revolutionary back when they were introduced
08:47	Empperi	but yeah, that was some time ago now :)
08:47	Empperi	world has gone forward
08:48	sharms	If I have a nested map of maps that occassionally has a {:key1 {:key2 {nil nil}} and want to create a new map with {nil nil} replaced with the (:key2 (:key1 another-map)), what is the clojure way to do it?
08:48	sharms	where :key1, :key2 ... :keyN
08:49	Empperi	use walk api
08:49	Empperi	https://clojuredocs.org/clojure.walk
08:50	sharms	Would you happen to know how I could get the keys required to get to the point I have walked to?
08:50	sharms	I have tried a few walk functions, tree seq etc but I am a bit hung up
08:51	the-kenny	Is there no way to use a :gen-class via `lein repl` without having to call `lein compile` first? I'd rather not introduce another step for devs to start developing
08:51	Empperi	well, your scenario isn't trivial
08:51	Empperi	would take some time to implement the solution with walk api
08:52	Empperi	would love to help but I've spent too much time doing all other stuff except the stuff I'm supposed to do :D
08:52	sharms	oh that is ok, I just wanted to make sure something like this wasn't a "oh just type this one line in" type thing
08:52	Empperi	don't want to sound like a total prick leaving you in distress but really, I need to do some work :/
08:52	Empperi	sorry
08:52	sharms	thank you for your help
09:33	the-kenny	Okay, I'm out of ideas: I've got a custom Exception generated via :gen-class in a namespace, foo.ValidationException. Now I want to import that in some other namespace, for example foo.model. As soon as I add it to the :import of foo.model, leiningen won't compile nor repl anymore, saying it can't find foo.ValidationException. I got it in my :aot in project.clj and tried every combination of aot, different
09:33	the-kenny	namespaces, adding :name to gen-class, requiring the namespace of the exception, running compile beforehand, etc. etc.
09:34	the-kenny	A colleague next to me did exact the same thing in clj-oauth2 before (some years ago): https://github.com/DerGuteMoritz/clj-oauth2/blob/master/src/clj_oauth2/OAuth2Exception.clj
09:34	the-kenny	All I get is ClassNotFoundExceptions everywhere.
09:36	the-kenny	The only "solution" I see right now is removing all usage of ValidationException in our codebase, running `lein compile`, then uncomment all usages.
09:40	justin_smith	do you require the namespace that defines the exception in the code that wants to throw that exception?
09:40	the-kenny	Tried that.
09:41	the-kenny	Same result.
09:41	justin_smith	if the namespace is compiled before the other namespace tries to use the class, then you should not see this error. You ensure this by using require.
09:41	justin_smith	OK
09:42	justin_smith	so you both require the namespace, you import the exception in the same ns that requires the namespace, and the exception defined in the required namespace is not available?
09:43	justin_smith	can you make a minimum reproduction of this error (eg. two namespaces, one tries to throw an exception defined in the other)?
09:43	the-kenny	Yeah, that's likely the next step.
09:43	the-kenny	Working on it, give me a minute
09:48	the-kenny	justin_smith: https://github.com/the-kenny/clojure-custom-exception-minimal-case
09:49	the-kenny	error is different, give me another minute. My brain doesn't really work today
09:49	the-kenny	okay, it works in that minimal example. I'll be damned
09:50	the-kenny	Okay, I'm getting some food and throw my day's work away afterwards and starting from scratch.
09:51	justin_smith	the-kenny: my suspicion is the whole package vs. namespace vs. class thing, it's a messy corner conceptually, even when people think they get it it's easy to confuse things
09:51	the-kenny	justin_smith: Yes, I'm aware of that. It's just that this is closest to the working example I've found. And I want to minimize the complexity.
09:53	justin_smith	I think the interactions are weird - the class does not exist unless you require the namespace but requiring the namespace doesn't import the class yadda yadda
09:54	Kah0ona	i've got something weird. I return a response with Content-Length 30705, but somehow it shows Content-Length 0 in the response header.
09:55	Kah0ona	It seems to be reset by compojure-api / compojure / ring?
09:55	Kah0ona	The header code is picked up, because if i change Content-Length to Content-Length2 it'll show that Content-Length2 header in the response
09:56	Kah0ona	how can i figure out which response middle ware (is there even such a thing?) is working in my compojure-api route?
09:56	justin_smith	Kah0ona: yeah, many middleware will alter the response
09:57	justin_smith	Kah0ona: the idea of a middleware is that it is free to alter the parameters before they hit your handler, or the response that comes out
09:57	Kah0ona	okay so how can i actually see what middleware is active? because my handler code just returns a response map of which I know it is correct
09:57	justin_smith	(by returning a new function that wraps a handler and does those things)
09:57	Empperi	Kah0ona: if you are using cursive then you can just use the debugger
09:57	justin_smith	Kah0ona: the only way I know of is to look into the compojure api code you are calling and seeing which middleware it inserts
09:57	Kah0ona	yeah i see the point of mw, but since there are some defaults being put in place by compojure-api
09:57	justin_smith	Empperi: oh, great point
09:58	justin_smith	Kah0ona: yeah, compojure-api is just a bunch of middlewares iirc
09:58	Empperi	well, that and some macro magic to build the route mapping :)
09:58	Kah0ona	yeah with some macro's that does some coercion and checking
09:58	Kah0ona	yeah
09:58	Kah0ona	okay so i gotta figure out which mw resets my content-length to 0
09:59	Empperi	pretty much
09:59	Empperi	default compojure-api mws shouldn't do it
09:59	Empperi	since we have compojure-api in use
09:59	Empperi	so I'd look at something else at first
09:59	Kah0ona	hmm don't have much else there actually...
10:00	Kah0ona	only some mw that modifies the request, but not the response
10:06	Empperi	so are you setting the content-length into your response headers correctly?
10:06	Empperi	and are you 100% certain of that?
10:06	Empperi	obviously ring cannot do that for you when you pass InputStream for it
10:08	justin_smith	,(.available (java.io.ByteArrayInputStream. (.getBytes "hello")))
10:08	clojurebot	5
10:08	justin_smith	not in the general case, but sometimes
10:13	Kah0ona	yeah i'm certain
10:13	Kah0ona	and i think the middleware: wrap-format-response causes it
10:13	Empperi	justin_smith: yeah but that is far from reliable
10:13	Kah0ona	https://github.com/ngrunwald/ring-middleware-format/blob/master/src/ring/middleware/format_response.clj#L202
10:14	Kah0ona	how can i disable that one for a certain route
10:14	Empperi	for a single route?
10:14	Kah0ona	i somehow find the compojure-api docs not really clear on how to disable a preconfigured mw
10:14	Kah0ona	yeah i have one /files?file_id=1
10:14	Kah0ona	route
10:14	Empperi	just define it separately from your other routes
10:15	justin_smith	Kah0ona: one option is a middleware wrapping that middleware that knows how to fix your Content-Length
10:15	Kah0ona	yeah but i defined it using compojure-api
10:15	justin_smith	Kah0ona: another is to replace the default middleware stack with something that behaves correctly
10:15	Kah0ona	ah like a new mw that undo's it
10:15	Kah0ona	hm
10:15	justin_smith	yeah, should be easy to write - it checks for your :real-content-length and applies it if present?
10:15	Empperi	hacky but would work
10:16	Kah0ona	ok i'll try that
10:16	justin_smith	the cleaner fix is to build your own custom middleware stack that isn't broken - depends on time available, how much work you want to put into it
10:16	Empperi	we actually have something like that in place for one of our custom middlewares
10:16	ikitommi_	Kah0ona: what mw's do you have outside of c-api `api`?
10:16	Empperi	which prevents it from doing it's magic for responses
10:16	Kah0ona	ah care to share?;-)
10:16	Empperi	Kah0ona: now you got compojure-api author to help you ;)
10:16	Empperi	ikitommi_ that is
10:16	Kah0ona	yeah i see that :-)
10:17	Kah0ona	well i dont have any that modify the response
10:17	Kah0ona	only some that modify the request
10:17	Kah0ona	atleast, as far as i can tell now
10:17	ikitommi_	can you throw in a gist?
10:17	Kah0ona	ikitommi_, : i'll make a little gist of the defroute
10:17	Kah0ona	yeah
10:17	Kah0ona	k
10:18	ikitommi_	the default mw-stack in c-api touches the reponse in two ways: 1) response coercion IF the endpoint has defined a Schema for it 2) using ring-middleware-format
10:20	ikitommi_	and the response coercion is defined in the endpoint, so if your route doesn't define a return schema, r-m-f is the only party doing something
10:20	justin_smith	ikitommi_: he just linked to the middleware that is setting his content-length - wrap-format-response
10:21	justin_smith	so maybe that means compojure-api is misled about the type of response or how to handle it?
10:22	Kah0ona	https://gist.github.com/Kah0ona/11c338cef61cd83ec7f0
10:22	Kah0ona	so i already got the hint of Empperi to _not_ put a `:return something` key in the options
10:23	Kah0ona	which got me around the default json encoder that tried to encode my file as json
10:23	Kah0ona	but now since content-length is always 0 i can't download my file (or it is empty that is)
10:23	Kah0ona	but it would be nice to also define this route in compojure-api
10:25	Kah0ona	for the purpose of this single route disabling the ring-middleware-format would probably fix my problem
10:25	ikitommi_	lot's of extra middlewares, is it possible to test without those?
10:25	Kah0ona	yeah okay i will try to disable them all
10:25	Deraen	r-m-f should do nothing with response body is not collection (i.e. it is Stream) and when no `:return` is not set
10:27	Kah0ona	by the way, i'll update the gist to show my file download function, which uses PipeInputStream
10:27	ikitommi_	yes, your compojure-api GET is really just a Compojure GET, so it's rendering rules apply (https://github.com/weavejester/compojure/blob/master/src/compojure/response.clj)
10:28	Kah0ona	one of which appearantly sets the Content-length automatically by checking the body, which, since it is a stream, doesnt give the correct Content-Length?
10:29	Kah0ona	so what is the best way to fix this?
10:29	clojurebot	Titim gan éirí ort.
10:30	Kah0ona	thanks so far by the way, for pointing in the right direction
10:31	Deraen	I don't think Compojure Renderable matters in this case. If response is map, it is used nearly as is.
10:32	ikitommi_	it could, if find-and-stream-file returns a stream and some evil external code has overridden the Stream-responses. Not likely thou.
10:32	Kah0ona	https://gist.github.com/Kah0ona/9c52f4932cc4de4219ae
10:33	Kah0ona	this is my fn that creates the stream by the way
10:33	cortexman	anyone using parinfer? https://github.com/edpaget/parinfer-mode
10:33	cortexman	(for emacs)
10:35	prohobo	hey guys, i have a problem
10:35	prohobo	nvm
10:35	TimMc	phew
10:36	Deraen	Interestingly file download code I have doesn't set content-length but the response has correct value, and the response body is a InputStream from Mongo GridFS
10:36	ikitommi_	Kah0ona: have to go, hopefully you find a solution for this with @Deraen & @Empperi
10:37	Kah0ona	yeah i go for the 'undo middle ware' approach
10:37	Kah0ona	thanks all
10:37	Kah0ona	then at least i think i ca nget it working without too much fuss
10:38	TimMc	I just took a look at the parinfer thing cortexman linked... it's weeeeeird.
10:38	justin_smith	sometimes you just have to add it to the "technical debt" list and go get other shit done, and some day you'll have the lightning bolt of inspiration that tells you how to fix it
10:38	justin_smith	TimMc: type python, get clojure
10:39	the-kenny	justin_smith: Found my issue. My user.clj required foo.core. And user being the repl's init-ns caused much much weirdness.
10:40	the-kenny	(my user ns requires core to use it in start/stop/reload for Component)
10:40	Deraen	Kah0ona: Btw. if the response is just a File, you don't need to turn it into Stream, you can just send File as response body
10:40	justin_smith	the-kenny: (dec user.clj)
10:41	justin_smith	because it's too easy to forget that it's modifying your environment
10:42	Kah0ona	Deraen aaahhhhh
10:42	the-kenny	yeah. We even moved it to dev-src/ so it's only loaded in dev environments. Very annoying.
10:42	Kah0ona	that's a good insight :)
10:42	Kah0ona	so just return a File?
10:43	Deraen	Yeah. And I think there is a good chance that content-length will be set automatically when you send a File.
10:43	Kah0ona	will definitely try now
10:47	Kah0ona	lol Deraen that did it
10:48	Kah0ona	and it removed like 10 lines of custom header building stuff
10:48	Kah0ona	just remove a File
10:48	Kah0ona	return*
10:48	Kah0ona	thanks man!!
10:48	justin_smith	awesome
10:48	Deraen	File response is mentioned in Ring wiki: https://github.com/ring-clojure/ring/wiki/Concepts#responses
10:48	Kah0ona	thanks
10:48	Kah0ona	yeah somehow i sometimes have trouble how thigns work together
10:49	Kah0ona	because at some point i'm working with compojure-api, and i now and then miss the link to how it pieces together with compojure/ring
10:49	Kah0ona	well bugs like this do make that more clear though :)
10:49	sdegutis	Good evening.
10:50	Kah0ona	good afternoon! ;-)
10:50	sdegutis	It's morning here.
10:51	Kah0ona	nice curveball then
10:51	Kah0ona	=0
10:51	Kah0ona	=)
10:52	Deraen	Looks like http server itself (e.g. http-kit) might overwrite content-length: https://github.com/http-kit/http-kit/blob/master/src/java/org/httpkit/HttpUtils.java#L437-L441 (check bodyBuffer method for code which handles File/InputStream etc. response bodies)
10:53	Deraen	Aleph checks if response already has content-length and only sets it if it is not already set :)
10:59	sdegutis	Hello.
11:00	sdegutis	Is there a way to make this template function prettier? http://sdegutis.github.io/2016-03-07/clojure-template-no-deps/
11:01	sdegutis	I'm trying to do it via fricken like -> and/or ->> etc but it like just aint workin or whatever
11:02	cortexman	i'm wondering if there's a way to use distinct (presumably as a stateful transducer) to distinct-ify objects based on a specific property
11:02	justin_smith	sdegutis: why not make that fn a helper with real variable names?
11:03	sdegutis	justin_smith: wait, what?
11:04	sdegutis	justin_smith: oh, you mean /instead/ of having a template function? like, each "usage" of (template) would actually be its own function?
11:04	sdegutis	justin_smith: kinda like this? (defn something [bar quux] (str "foo " bar " " bar " " quux)) ?
11:04	justin_smith	like (defn apply-key-to-template [s from to] (str/replace s (str "{{" from "}}") to)) (reduce (fn [s [k v]] (apply-key-to-template s (name k) v)) s m)
11:05	sdegutis	justin_smith: interestingly enough, I have done that in most places where I was using clostache (which I removed yesterday because it is a clustercluck on clojars and the latest version(s) are all broken with regard to dollar signs)
11:05	sdegutis	oh
11:05	sdegutis	justin_smith: never mind my last statement to you then
11:05	sdegutis	justin_smith: I'm always hesitant to make helper functions like that, but..
11:06	sdegutis	justin_smith: yeah, even in this case I'm hesitant to extract a helper function (even if it's private) for very little gain
11:06	justin_smith	sdegutis: bonus with that approach is that things like {{{}}} etc. become much easier
11:06	justin_smith	or if you want things that call helpers in templates
11:06	justin_smith	etc.
11:07	sdegutis	hm
11:07	justin_smith	that is, the gain is more if you plan on allowing different kinds of substitution
11:07	justin_smith	if you only do that one kind? leave it as is, it's fine
11:07	sdegutis	justin_smith: I see
11:08	justin_smith	and if you don't plan on doing more than simple substitution, why are you even writing this yourself? lots of libs do that
11:08	sdegutis	Wow. It's hard to imagine that only a year ago I was interested in Haskell and seriously considered it a viable alternative to Clojure: http://sdegutis.github.io/2015-02-10/haskell/
11:09	sdegutis	That blog post was extracted from an email I sent to my employers in hopes it might persuade them to consider Haskell instead of Clojure.
11:10	justin_smith	sdegutis: so if you had more than one kind of interpolation it would be like (comp (apply-key-to-template k v) (apply-escaped-key-to-template k v) (apply-helper-to-template k v)) where each returns a function that takes and returns the template itself
11:10	sdegutis	justin_smith: ah I see now, neat
11:11	sdegutis	justin_smith: that would be a cool start to an alternative templating library, possibly one with more configurability than clostache has
11:11	justin_smith	sdegutis: and you could have evil recursive templates if you repeat all steps until output string is equal to input
11:11	justin_smith	haha
11:12	sdegutis	Unfortunately I don't believe I'd ever like such a library. My preferred templating library so far is (comp (partial apply str) (flatten))
11:12	sdegutis	Oops I meant (comp (partial apply str) flatten)
11:13	sdegutis	So that you can just return any number of levels of nested strings and then just string-build those suckers together.
11:13	sdegutis	That works easiest with the sequence-transforming functions in clojure.core, e.g. for, reduce, range, take-while, etc.
11:14	sdegutis	~flatten
11:14	clojurebot	flatten is rarely the right answer. Suppose you need to use a list as your "base type", for example. Usually you only want to flatten a single level, and in that case you're better off with concat. Or, better still, use mapcat to produce a sequence that's shaped right to begin with.
11:14	sdegutis	WRONG clojurebot, you're WRONG
11:15	rcassidy	Heh
11:15	justin_smith	:b4
11:17	sdegutis	?
11:17	justin_smith	sdegutis: I added a plugin to my irc client, sometimes I use that plugin wrong
11:17	sdegutis	silly justin
11:18	justin_smith	sdegutis: you can pretend that says "C-u 4 M-x switch-to-buffer-by-number"
11:18	sdegutis	haha
11:19	justin_smith	this is simple, but not yet familiar (I think a clojure user can recognize that these can be separate things)
11:19	sdegutis	oh for sure, I'm an Emacs user remember? :P
11:19	sdegutis	Emacs is as simple as it can be for my usage given my needs
11:20	sdegutis	anything simpler would cripple my productivity
11:20	sdegutis	also I feel so bad for people who use vim
11:20	sdegutis	like, how can you get anything done in vim?
11:20	justin_smith	sdegutis: your sympathy is noted and appreciated.
11:20	sdegutis	maybe there is a way I just didn't learn about back when I used vim/mvim for a few years
11:21	sdegutis	haha justin_smith you dont use vim
11:21	justin_smith	sdegutis: I used evil for a while, it is an easy switch. I used evil because my wrists are mortal and are vulnerable to key chording.
11:21	sdegutis	haha
11:21	sdegutis	justin_smith: but even when I did use vim, I was always using chords, because you just can't use vim without them
11:21	sdegutis	C-r "
11:21	sdegutis	that's a common one
11:21	justin_smith	sdegutis: I know otherwise. I never use C-r "
11:22	justin_smith	I don't even know what that does
11:22	sdegutis	how do you paste from " then justin_smith?
11:22	sdegutis	justin_smith: it's a way to paste from " which is like some special thing
11:22	sdegutis	lemme go look it up
11:22	justin_smith	"*p pastes from my system clipboard
11:22	sdegutis	hmm
11:22	sdegutis	oh wait
11:22	justin_smith	"<foo>p pastes from foo
11:22	sdegutis	i remember now i think
11:22	sdegutis	C-r " is like when you need to paste while you're in the fake-minibuffer-thing
11:23	sdegutis	that's what it was
11:23	justin_smith	oh, I don't find myself doing that, maybe I'm not yet advanced enough for such things
11:23	sdegutis	i like how in emacs the minibuffer has the same commands as any other buffer for the most part, so you can backtrack with C-b and copy with M-w etc
11:23	sdegutis	justin_smith: dont worry ull get there in time
11:24	justin_smith	sdegutis: the top priority for me is nothing I do average 10 times a minute or more should be a chord. In vim I have a workflow that pulls that off (given I can use alternate hand for the shift key)
11:26	amalloy	but where will you find time for piano practice?
11:27	sdegutis	amalloy: i dont get it
11:27	justin_smith	amalloy: some day the jazz world will appreciated my unique pointellistic style without chords
11:28	amalloy	sdegutis: if the audience doesn't get it, it wasn't a joke after all
11:28	sdegutis	amalloy: i vaguely remember that i had practiced piano in like 2013, but i dont recall any association between that and our current vim vs emacs conversation
11:29	amalloy	chords
11:29	sdegutis	amalloy: oh man wow yeah i got that it just seemed a little too obvious for an amalloy joke
11:30	sdegutis	btw, ive given my kids piano sheet music for FFVII songs, and they're killin it
11:30	sdegutis	i love hearin that while i work, its amazing
11:31	sdegutis	like, right now, my 12yo son is playing Forested Temple on the piano by ear.. i go and ask him "where did you even hear that?" because he doesnt have sheet music for it, and he said "from your room [office]" lol!!
11:32	justin_smith	sdegutis: https://www.youtube.com/watch?v=Y-Elr5K2Vuo
11:34	sdegutis	also he fricken did Rocky Maridia for his piano recital https://www.youtube.com/watch?v=nAR38Rf4ig4
11:34	sdegutis	which btw is a song off the Super Metroid soundtrack :D
11:41	sdegutis	I'm still trying to figure out the best way to use Components with a Router component. It feels very ugly to pass the whole system component into the Router component, but it feels even uglier to pass almost every single other component in the system through the router.
11:41	sdegutis	This is on account of how the whole Router contains many different kinds of routes, each of which use only some of the system's components, but all of which use almost all of them (probably all except the router).
11:42	sdegutis	I suppose splitting the routes up and giving them to the Router, per justin_smith's previous suggestion, is one way of de-tangling this, but then each route needs to become its own Component, which feels unnecessarily heavy.
11:43	justin_smith	sdegutis: what about letting each component define middlewares, and composing those in your router
11:43	justin_smith	all stateful stuff would be provided via middleware, and not directly in the handler definition
11:43	sdegutis	In my experience, Components and/or Records should only be used when a bit of functionality (1) needs to be started/stopped, (2) comes with configuration that it would like to have initialized with only once and carried with it through the lifetime of the system, or (3) I forgot #3.
11:44	justin_smith	sdegutis: right, and a middleware can be a bridge so that a handler (which the components need not know about / handle) can access something stateful
11:45	sdegutis	Oh right, (3) is when the thing inherently affects an external service (such as sending a live email) and it would be handy to have a "fake" version of that thing.
11:46	sdegutis	And in #3, there would be a Protocol that handles the thing, a live Record and a fake (usually in-memory) Record which both implement the Protocol, which inherently conform to Components and can be reasonably considered a stand-alone component in a system.
11:46	sdegutis	justin_smith: that's just an implementation technique of how to include all the system components in the router
11:47	sdegutis	justin_smith: it still comes with the drawback of having all the individual system components being passed to the router and thus the individual routes (via the request map).
11:47	justin_smith	not if you explicitly pass in only the middlewares - you can have each component optionally return a :middlewares key with a hash-map of keys to middleware provided
11:48	justin_smith	then the exposure is just the middlewares you pass in
11:49	sdegutis	justin_smith: afaiu, that's just a slight inversion of where the middlewares are defined; but the routes still need to access the component's provided functionality via a key in the request map, right?
11:50	justin_smith	the component decides how its state / functionality is exposed
11:51	justin_smith	via its definition of the middleware
11:51	justin_smith	I think that's going to allow clean isolation
11:53	justin_smith	for example it can provide a query function, instead of a handle to the db itself
12:05	sdegutis	justin_smith: I was thinking it would just provide itself to the request map; for example, the middleware would just (assoc request :db-conn db-conn-component), and then routes would access it via (:db-conn request) and use it like (myapp.interfaces.db-conn/query (:db-conn request)) assuming that query function lives in a Protocol or something.
12:05	sdegutis	Also, I cleaned up my thoughts about Components and put them at http://sdegutis.github.io/2016-03-08/when-to-use-clojure-components/ for everyone here
12:06	justin_smith	sdegutis: but if you do it that way, you need to mock a db. If you provide a query facade, that's much easier to test with, you just pass in a stub for the query facade instead of needing to mock a db api.
12:06	justin_smith	that's my theory at least.
12:07	sdegutis	hmm
12:08	RedNifre	Hey there clojuristas.
12:09	RedNifre	,(+ 1 2)
12:09	clojurebot	3
12:09	RedNifre	clojurebot step up your game, you're getting slow!
12:09	RedNifre	,(def y)
12:09	clojurebot	#'sandbox/y
12:10	sdegutis	,(def x #'x)
12:10	clojurebot	#'sandbox/x
12:10	mokuso	hehe
12:10	mavbozo	,(get get get get)
12:10	clojurebot	#object[clojure.core$get 0x6ab31f44 "clojure.core$get@6ab31f44"]
12:10	sdegutis	,x
12:10	clojurebot	#'sandbox/x
12:10	sdegutis	,(x)
12:10	clojurebot	#error {\n :cause nil\n :via\n [{:type java.lang.StackOverflowError\n :message nil\n :at [clojure.lang.Var fn "Var.java" 363]}]\n :trace\n [[clojure.lang.Var fn "Var.java" 363]\n [clojure.lang.Var invoke "Var.java" 375]\n [clojure.lang.Var invoke "Var.java" 375]\n [clojure.lang.Var invoke "Var.java" 375]\n [clojure.lang.Var invoke "Var.java" 375]\n [clojure.lang.Var invoke "Var.java" 375]...
12:10	sdegutis	HAHAHA
12:10	RedNifre	That output isn't that helpful in my case.
12:10	RedNifre	See, I have troubles understanding what an unbound var is.
12:10	justin_smith	RedNifre: do you know what a var is?
12:11	mokuso	'(expt 2 2)
12:11	mokuso	,'(expt 2 2)
12:11	clojurebot	(expt 2 2)
12:11	mokuso	,(expt 2 2)
12:11	clojurebot	#error {\n :cause "Unable to resolve symbol: expt in this context"\n :via\n [{:type clojure.lang.Compiler$CompilerException\n :message "java.lang.RuntimeException: Unable to resolve symbol: expt in this context, compiling:(NO_SOURCE_PATH:0:0)"\n :at [clojure.lang.Compiler analyze "Compiler.java" 6688]}\n {:type java.lang.RuntimeException\n :message "Unable to resolve symbol: expt in this co...
12:11	RedNifre	When I do this in the REPL: (def y) (def x y) (def z) then it looks like x and y point to the same "nothing" but z points to a different "nothing".
12:11	mokuso	meh
12:11	RedNifre	What exactly does this output mean: #object[clojure.lang.Var$Unbound 0x15b5893c "Unbound: #'user/y"]
12:11	mokuso	,(math/expt 2 2)
12:11	clojurebot	#error {\n :cause "No such namespace: math"\n :via\n [{:type clojure.lang.Compiler$CompilerException\n :message "java.lang.RuntimeException: No such namespace: math, compiling:(NO_SOURCE_PATH:0:0)"\n :at [clojure.lang.Compiler analyze "Compiler.java" 6688]}\n {:type java.lang.RuntimeException\n :message "No such namespace: math"\n :at [clojure.lang.Util runtimeException "Util.java" 221]}]...
12:11	justin_smith	RedNifre: a var is a container. (def x y) points the container x to hold the uninitialized default value held in the container y
12:12	RedNifre	What's an uninitialized default value? It sounds like it's different from nil?
12:12	mokuso	,(Math/pow 2 2)
12:12	clojurebot	4.0
12:12	justin_smith	RedNifre: yes, it is
12:12	justin_smith	,(def x)
12:12	clojurebot	#'sandbox/x
12:12	justin_smith	,x
12:12	clojurebot	#'sandbox/x
12:12	justin_smith	ahh, x already existed
12:12	justin_smith	,(def uninitialized)
12:12	clojurebot	#'sandbox/uninitialized
12:12	sdegutis	,(x x)
12:12	clojurebot	#error {\n :cause nil\n :via\n [{:type java.lang.StackOverflowError\n :message nil\n :at [clojure.lang.Var invoke "Var.java" 379]}]\n :trace\n [[clojure.lang.Var invoke "Var.java" 379]\n [clojure.lang.Var invoke "Var.java" 379]\n [clojure.lang.Var invoke "Var.java" 379]\n [clojure.lang.Var invoke "Var.java" 379]\n [clojure.lang.Var invoke "Var.java" 379]\n [clojure.lang.Var invoke "Var.ja...
12:12	sdegutis	,(x x x)
12:12	justin_smith	,uninitialized
12:12	clojurebot	#object[clojure.lang.Var$Unbound 0x1317c009 "Unbound: #'sandbox/uninitialized"]
12:12	clojurebot	#error {\n :cause nil\n :via\n [{:type java.lang.StackOverflowError\n :message nil\n :at [clojure.lang.Var invoke "Var.java" 383]}]\n :trace\n [[clojure.lang.Var invoke "Var.java" 383]\n [clojure.lang.Var invoke "Var.java" 383]\n [clojure.lang.Var invoke "Var.java" 383]\n [clojure.lang.Var invoke "Var.java" 383]\n [clojure.lang.Var invoke "Var.java" 383]\n [clojure.lang.Var invoke "Var.ja...
12:13	mokuso	,(Math/pow 2 (Math/pow 2 4))
12:13	clojurebot	65536.0
12:13	mavbozo	,(deref #'sandbox/uninitialized)
12:13	clojurebot	#object[clojure.lang.Var$Unbound 0x1317c009 "Unbound: #'sandbox/uninitialized"]
12:13	RedNifre	Yeah, so there is this "Unbound" thing and it has this hex number. What's up with that?
12:13	justin_smith	RedNifre: an unbound var is automatically given that special value - an instance of clojure.lang.Var$Unbound
12:13	justin_smith	RedNifre: $ is jvm syntax for an inner class
12:13	justin_smith	Unbound is a class created inside Var
12:14	RedNifre	Okay, so there is a type Var$Unbound and every unbound var gets a newly created value of that type assigned?
12:14	justin_smith	unbound vars are initialized to hold an instance of unbound
12:14	sdegutis	,(apply apply (repeat 10 (constantly 9)))
12:14	clojurebot	#error {\n :cause "Don't know how to create ISeq from: clojure.core$constantly$fn__4614"\n :via\n [{:type java.lang.IllegalArgumentException\n :message "Don't know how to create ISeq from: clojure.core$constantly$fn__4614"\n :at [clojure.lang.RT seqFrom "RT.java" 542]}]\n :trace\n [[clojure.lang.RT seqFrom "RT.java" 542]\n [clojure.lang.RT seq "RT.java" 523]\n [clojure.core$seq__4357 invokeS...
12:14	mavbozo	,(type uninitialized)
12:14	clojurebot	clojure.lang.Var$Unbound
12:14	justin_smith	RedNifre: exactly
12:14	RedNifre	So it's kinda like nil except that there's only one nil but many unbound?
12:14	justin_smith	RedNifre: and it's less ambiguous where an Unbound came from
12:14	mavbozo	,(def un-init-0)
12:14	clojurebot	#'sandbox/un-init-0
12:14	justin_smith	RedNifre: there's so many ways to generate or end up accidentally with nil
12:14	mavbozo	,(def un-init-1)
12:14	clojurebot	#'sandbox/un-init-1
12:15	mavbozo	,(= un-init-0 un-init-1)
12:15	clojurebot	false
12:15	justin_smith	RedNifre: the two ways to get an Unbound are to not yet bind a var, or create one on purpose
12:15	RedNifre	Well, but there's only one null in Java and null is thus equal to null. Is the same true for nil in Clojure? I gather that comparing two unbound vars would be false since they contain different unbounds?
12:15	justin_smith	RedNifre: nil is null
12:15	justin_smith	there is no distinction
12:15	justin_smith	same thing, two names
12:16	RedNifre	okay, so only one nil and it's equal to itself. got it.
12:17	RedNifre	Are nil and Unbound the only "nothings" in Clojure or are there more? E.g. JavaScript also has undefined which is what you get when you read from a nonexistant var (where Clojure would throw an exception).
12:18	justin_smith	hmm, does Double/NaN count?
12:18	justin_smith	different kind of not a thing
12:18	RedNifre	I guess so, I mean NaN is for Doubles what null is for objects, huh?
12:18	justin_smith	there's also a promise that is not realized
12:18	justin_smith	which is also different but kind of "nothing yet"
12:19	sdegutis	NaN is just weird, never use NaN
12:19	sdegutis	and never use Doubles or Floats.
12:19	sdegutis	Prefer to use Strings for all your number manipulation.
12:19	justin_smith	doubles and floats would be less useful without NaN though
12:20	RedNifre	I'm not a fan of NaN either.
12:21	justin_smith	would you prefer (/ 0.0 0.0) throw an exception?
12:21	justin_smith	(not to mention various usages of trig functions)
12:21	mavbozo	,(/ 0.0 0.0)
12:21	RedNifre	I'm not sure. Maybe.
12:21	clojurebot	NaN
12:21	sdegutis	It's interesting how often I end up using (reduce).
12:22	RedNifre	In the REPL, can I undef something?
12:22	justin_smith	RedNifre: yes, you can
12:22	sdegutis	'reduce' is the simplest functionally pure way of transforming something based on the current and any/all past elements in a sequence.
12:22	RedNifre	Great. When I need it I'll ask how.
12:22	justin_smith	RedNifre: remembering...
12:23	justin_smith	ns-unmap
12:23	justin_smith	I keep forgetting that name though, I keep wanting unintern or something
12:26	RedNifre	Hm, how to use it? From (doc ns-unmap) I thought I should do (ns-unmap user y) but that complains about not finding user.
12:26	justin_smith	RedNifre: it wants symbols
12:26	justin_smith	(ns-unmap 'user 'y)
12:26	justin_smith	that's why I expect it to be called unintern, intern also uses symbols
12:26	RedNifre	ah.
12:27	RedNifre	How do I fetch the current ns?
12:27	justin_smith	,ns
12:27	clojurebot	#object[clojure.lang.Namespace 0x29fac779 "sandbox"]
12:27	sdegutis	,(ns-unmap ns 'map)
12:27	clojurebot	nil
12:27	justin_smith	ns-unmap will accept that value
12:27	sdegutis	Hahahha stupid clojurebot.
12:27	justin_smith	,(map inc [0])
12:27	clojurebot	(1)
12:27	sdegutis	,(map inc [1 2 3])
12:27	clojurebot	(2 3 4)
12:27	sdegutis	wha?
12:28	RedNifre	Do these asterisks have a special meaning or is it just the name of the function?
12:28	sdegutis	Oh, it probably creates a new ns every time? or something?
12:28	sdegutis	,ns
12:28	clojurebot	#object[clojure.lang.Namespace 0x29fac779 "sandbox"]
12:28	sdegutis	,ns
12:28	clojurebot	#object[clojure.lang.Namespace 0x29fac779 "sandbox"]
12:28	sdegutis	hmmmmm
12:28	justin_smith	sdegutis: you maybe want ns-unalias
12:28	sdegutis	justin_smith: no i dont think so
12:28	sdegutis	ns-unmap worked locally for me
12:28	justin_smith	,(ns-unalias ns 'map)
12:28	clojurebot	nil
12:28	sdegutis	justin_smith: alias is for things like str
12:28	justin_smith	,(map inc [0])
12:28	clojurebot	(1)
12:28	sdegutis	clojure.string :as str = alias
12:28	justin_smith	hrm
12:28	justin_smith	OK
12:28	justin_smith	sdegutis: must be clojurebot weirdness then
12:29	sdegutis	,(do (ns-unmap ns 'map) (map inc [1 2 3]))
12:29	RedNifre	,(def undef [symbol] (ns-unmap ns symbol))
12:29	clojurebot	#error {\n :cause "Unable to resolve symbol: map in this context"\n :via\n [{:type clojure.lang.Compiler$CompilerException\n :message "java.lang.RuntimeException: Unable to resolve symbol: map in this context, compiling:(NO_SOURCE_PATH:0:0)"\n :at [clojure.lang.Compiler analyze "Compiler.java" 6688]}\n {:type java.lang.RuntimeException\n :message "Unable to resolve symbol: map in this conte...
12:29	clojurebot	#error {\n :cause "Too many arguments to def"\n :via\n [{:type clojure.lang.Compiler$CompilerException\n :message "java.lang.RuntimeException: Too many arguments to def, compiling:(NO_SOURCE_PATH:0:0)"\n :at [clojure.lang.Compiler analyzeSeq "Compiler.java" 6875]}\n {:type java.lang.RuntimeException\n :message "Too many arguments to def"\n :at [clojure.lang.Util runtimeException "Util.jav...
12:29	sdegutis	,(map inc [1 2 3])
12:29	clojurebot	(2 3 4)
12:29	RedNifre	,(defn undef [symbol] (ns-unmap ns symbol))
12:29	sdegutis	WHA
12:29	clojurebot	#'sandbox/undef
12:29	sdegutis	i think whoever writes clojurebot wised up after i did this last time (2013 maybe?)
12:29	RedNifre	(def backupinc inc)
12:29	RedNifre	,(def backupinc inc)
12:29	clojurebot	#'sandbox/backupinc
12:29	RedNifre	,(undef inc)
12:29	clojurebot	#error {\n :cause "clojure.core$inc cannot be cast to clojure.lang.Symbol"\n :via\n [{:type java.lang.ClassCastException\n :message "clojure.core$inc cannot be cast to clojure.lang.Symbol"\n :at [clojure.core$ns_unmap invokeStatic "core.clj" 4048]}]\n :trace\n [[clojure.core$ns_unmap invokeStatic "core.clj" 4048]\n [clojure.core$ns_unmap invoke "core.clj" 4048]\n [sandbox$undef invokeStatic ...
12:30	sdegutis	,(ns-unmap 'clojure.core 'map)
12:30	clojurebot	nil
12:30	sdegutis	(map inc [1 2 3])
12:30	sdegutis	,(map inc [1 2 3])
12:30	clojurebot	#error {\n :cause "Attempting to call unbound fn: #'clojure.core/map"\n :via\n [{:type java.lang.IllegalStateException\n :message "Attempting to call unbound fn: #'clojure.core/map"\n :at [clojure.lang.Var$Unbound throwArity "Var.java" 43]}]\n :trace\n [[clojure.lang.Var$Unbound throwArity "Var.java" 43]\n [clojure.lang.AFn invoke "AFn.java" 36]\n [sandbox$eval399 invokeStatic "NO_SOURCE_FIL...
12:30	sdegutis	HAHAHAHA
12:30	sdegutis	oh wait
12:30	sdegutis	oops. sorry everyone.
12:30	mike7	,(loop for c across "abc" collect c)
12:30	clojurebot	#error {\n :cause "loop requires a vector for its binding in sandbox:"\n :via\n [{:type java.lang.IllegalArgumentException\n :message "loop requires a vector for its binding in sandbox:"\n :at [clojure.core$loop invokeStatic "core.clj" 4425]}]\n :trace\n [[clojure.core$loop invokeStatic "core.clj" 4425]\n [clojure.core$loop doInvoke "core.clj" 4419]\n [clojure.lang.RestFn invoke "RestFn.java...
12:30	RedNifre	Hm, did you assign map to a backup var first or is it now gone forever?
12:31	sdegutis	,(do (ns clojure.core) (defn map "Returns a lazy sequence consisting of the result of applying f to the set of first items of each coll, followed by applying f to the set of second items in each coll, until any one of the colls is exhausted. Any remaining items in other colls are ignored. Function f should accept number-of-colls arguments. Returns a transducer when no collection is provided." {:added "1.0" :static true
12:31	sdegutis	} ([f] (fn [rf] (fn ([] (rf)) ([result] (rf result)) ([result input] (rf result (f input))) ([result input & inputs] (rf result (apply f input inputs)))))) ([f coll] (lazy-seq (when-let [s (seq coll)] (if (chunked-seq? s) (let [c (chunk-first s) size (int (count c)) b (chunk-buffer size)] (dotimes [i size] (chunk-append b (f (.nth c i)))) (chunk-cons (chunk b) (map f (chunk-rest s)))) (cons (f (first s)) (map f (rest s)
12:31	sdegutis	)))))) ([f c1 c2] (lazy-seq (let [s1 (seq c1) s2 (seq c2)] (when (and s1 s2) (cons (f (first s1) (first s2)) (map f (rest s1) (rest s2))))))) ([f c1 c2 c3] (lazy-seq (let [s1 (seq c1) s2 (seq c2) s3 (seq c3)] (when (and s1 s2 s3) (cons (f (first s1) (first s2) (first s3)) (map f (rest s1) (rest s2) (rest s3))))))) ([f c1 c2 c3 & colls] (let [step (fn step [cs] (lazy-seq (let [ss (map seq cs)] (when (every? identity ss)
12:31	clojurebot	#<RuntimeException java.lang.RuntimeException: EOF while reading>
12:31	sdegutis	(cons (map first ss) (step (map rest ss)))))))] (map #(apply f %) (step (conj colls c3 c2 c1)))))))
12:31	sdegutis	hmm
12:31	sdegutis	yeah we'll just have to wait til clojurebot resets its jvm which afaik happens every few minutes
12:31	sdegutis	my bad.
12:31	RedNifre	Or you just write a new map, using for or something :)
12:32	sdegutis	Smart RedNifre.
12:32	sdegutis	,map
12:33	clojurebot	#object[clojure.core$map 0x753294f6 "clojure.core$map@753294f6"]
12:33	sdegutis	its back i guess
12:34	RedNifre	,(defn varargs [a & b] (vector a b))
12:34	clojurebot	#'sandbox/varargs
12:34	RedNifre	,(varargs 1 2)
12:34	clojurebot	[1 (2)]
12:34	RedNifre	,(varargs 1)
12:34	clojurebot	[1 nil]
12:34	RedNifre	Why does the vararg parameter turn into nil instead of () ?
12:35	sdegutis	,(apply (repeat 5 varargs))
12:35	clojurebot	#error {\n :cause "Wrong number of args (1) passed to: core/apply"\n :via\n [{:type clojure.lang.ArityException\n :message "Wrong number of args (1) passed to: core/apply"\n :at [clojure.lang.AFn throwArity "AFn.java" 429]}]\n :trace\n [[clojure.lang.AFn throwArity "AFn.java" 429]\n [clojure.lang.RestFn invoke "RestFn.java" 412]\n [sandbox$eval118 invokeStatic "NO_SOURCE_FILE" 0]\n [sandbox...
12:35	RedNifre	Is it because nil is falsy so it's easier to check whether there are any extra args?
12:35	sdegutis	,(apply apply (repeat 5 varargs))
12:35	clojurebot	#error {\n :cause "Don't know how to create ISeq from: sandbox$varargs"\n :via\n [{:type java.lang.IllegalArgumentException\n :message "Don't know how to create ISeq from: sandbox$varargs"\n :at [clojure.lang.RT seqFrom "RT.java" 542]}]\n :trace\n [[clojure.lang.RT seqFrom "RT.java" 542]\n [clojure.lang.RT seq "RT.java" 523]\n [clojure.lang.RT cons "RT.java" 662]\n [clojure.core$cons__4331 ...
12:35	sdegutis	I'm confused.
12:35	sdegutis	RedNifre: because it probably uses 'next
12:35	RedNifre	,(varargs 1 2 3 4)
12:35	clojurebot	[1 (2 3 4)]
12:36	RedNifre	sdegutis I don't understand that explanation, what's 'next?
12:36	sdegutis	,(map (juxt next rest) [[] [1] [1 2]])
12:36	clojurebot	([nil ()] [nil ()] [(2) (2)])
12:36	sdegutis	Hmm. That wasn't very clear.
12:36	sdegutis	RedNifre: sorry i meant #'next but yeah i could be wrong
12:36	RedNifre	Well, I understand nothing since I just started with the Joy of Clojure book :)
12:37	sdegutis	RedNifre: ok
12:37	sdegutis	bbl
12:38	RedNifre	Speaking of JoC, they write that they prefer to always use numbered % e.g. #(bla %1). I find that strange, why number parameters if there's only one? Isn't #(bla %) simpler in this case? Why number it?
12:39	ridcully	% is just fine; using %1 %2 i find polite to signal, that there is some higher arity at work
12:42	RedNifre	,(defn fib ([1] 1) ([2] 1) ([n] (- n 2) (- n 1))))
12:42	clojurebot	#error {\n :cause "Unsupported binding form: 1"\n :via\n [{:type clojure.lang.Compiler$CompilerException\n :message "java.lang.Exception: Unsupported binding form: 1, compiling:(NO_SOURCE_PATH:0:0)"\n :at [clojure.lang.Compiler analyzeSeq "Compiler.java" 6875]}\n {:type java.lang.Exception\n :message "Unsupported binding form: 1"\n :at [clojure.core$destructure$pb__5167 invoke "core.clj" ...
12:42	RedNifre	What's the correct way to write what I mean?
12:42	sdegutis	Hi!
12:42	RedNifre	howdy
12:42	RedNifre	,(defn fib ([1] 1) ([2] 1) ([n] (- n 2) (- n 1))))
12:42	clojurebot	#error {\n :cause "Unsupported binding form: 1"\n :via\n [{:type clojure.lang.Compiler$CompilerException\n :message "java.lang.Exception: Unsupported binding form: 1, compiling:(NO_SOURCE_PATH:0:0)"\n :at [clojure.lang.Compiler analyzeSeq "Compiler.java" 6875]}\n {:type java.lang.Exception\n :message "Unsupported binding form: 1"\n :at [clojure.core$destructure$pb__5167 invoke "core.clj" ...
12:42	RedNifre	:/
12:42	amalloy	RedNifre: there's no pattern matching
12:43	amalloy	but also (- n 2) (- n 1) doesn't make sense even if there were
12:43	RedNifre	why not?
12:43	RedNifre	Yeah, I meant ([n] (+ (fib (- n 2)) (fib (- n 1))))
12:44	RedNifre	So how to write this correctly then?: (defn fib ([1] 1) ([2] 1) ([n] (+ (fib (- n 2)) (fib (- n 1)))))
12:47	ridcully	RedNifre: http://rosettacode.org/wiki/Fibonacci_sequence#Clojure
12:49	sdegutis	Good evening.
12:50	sdegutis	amalloy: hmm, his pattern matching idea would be really cool though
12:50	sdegutis	It'd be like a version of defn that has core.match built in.
12:50	sdegutis	That said, I would have basically no need for it ever.
12:50	sdegutis	The only time I /might/ use it is to replace uses of defmulti/defmethod.
12:50	sdegutis	But even then, I might as well just use (case x) within the (defn foo [x] ...)
12:51	RedNifre	Thanks for the rosetta link ridcully. Hm, core.match sounds like it might be interesting as well, I'll check that out next.
12:51	justin_smith	the big gotcha is if you combine core.match with things like core.logic or core.async in the same code, it is easy to get method-too-large errors
12:52	RedNifre	what's a method-too-large error?
12:52	justin_smith	the jvm has a maximum method size for the resulting bytecode
12:52	ridcully	RedNifre: there is also https://github.com/killme2008/defun - i have never tried it, but it looks like it could make your initial version working (it uses core match under the hood)
12:53	justin_smith	RedNifre: since core.async, core.logic, and core.match all do a lot of code generation, combining them can hit that limit
12:53	RedNifre	Uhm, I thought the bytecode limit was 64KiB? Shouldn't that be enough for everybody?
12:53	justin_smith	RedNifre: you haven't macroexpanded core.async code have you
12:55	RedNifre	huh, interesting.
12:55	RedNifre	did that ever happen to you? if so, what did you do about it?
12:55	amalloy	i mean, core.match has something like defn built in. defne or something
12:55	justin_smith	RedNifre: https://gist.github.com/noisesmith/0fd7db0d239113c1d0c8
12:55	amalloy	RedNifre: you can macroexpand into some pretty silly stuff
12:56	amalloy	i actually saw a co-worker go over the 64KB limit in java
12:56	RedNifre	I'm new to clojure so I don't know what "macroexpand" means. Does it mean looking at the code that gets compiled after all macros got expanded?
12:57	justin_smith	RedNifre: exactly
12:57	amalloy	basically by trying to hard-code a several-megabyte Map<String, String>, using sed or something to produce a series of .put calls from a text file
12:57	justin_smith	amalloy: nice
12:57	RedNifre	okay, so core-async sounds like it contains macros that add a lot of "synchronized" and locks and stuff like that everywhere?
12:58	amalloy	RedNifre: a lot of things you do are macros underneath, some of them quite involved
12:58	amalloy	,(macroexpand-1 '(for [x (range 10), y [x (- x)]] (/ y 10)))
12:58	clojurebot	(clojure.core/let [iter__5216__auto__ (clojure.core/fn iter__27 [s__28] (clojure.core/lazy-seq (clojure.core/loop [s__28 s__28] (clojure.core/when-first [x s__28] (clojure.core/let [iterys__5212__auto__ (clojure.core/fn iter__29 [s__30] (clojure.core/lazy-seq #)) fs__5213__auto__ (clojure.core/seq (iterys__5212__auto__ #))] (if fs__5213__auto__ (clojure.core/concat fs__5213__auto__ (iter__27 #)) (...
12:58	hiredman	the go macro in core.async doesn't expand to any calls to thing like syncronized (locking)
12:58	RedNifre	Well, generating a lot of .put calls in Java from a text file through sed is kinda the same as using macros in clojure, huh?
12:58	amalloy	well, try that in your repl; it's much too large to fit here
12:59	RedNifre	can macros read external files?
12:59	hiredman	the locking is all inside the channel operations
12:59	amalloy	RedNifre: the difference is that in clojure you can use clojure
12:59	sdegutis	,(defn correct-answer-for [q] (->> q (reverse) (apply str) (read-string) (name) (reverse) (apply str)))
12:59	clojurebot	#'sandbox/correct-answer-for
12:59	sdegutis	,(correct-answer-for "Which is better? Ice cream or pizza")
12:59	amalloy	in java you ahve to use sed
12:59	clojurebot	"pizza"
12:59	sdegutis	,(correct-answer-for "sdegutis is better at Clojure than amalloy: true or false")
12:59	clojurebot	"false"
12:59	RedNifre	i.e. could I have a macro (big-string-map-from-file "stuff.txt") that expands into a giant map with the text file in it?
12:59	sdegutis	,(defn correct-answer-for [q] (->> q (reverse) (apply str) (read-string) (name) (reverse) (apply str) (read-string)))
12:59	clojurebot	#'sandbox/correct-answer-for
13:00	amalloy	RedNifre: you can, but you generally shouldn't
13:00	ridcully	RedNifre: yes, that works. i found that a nice way to have configs etc in clojurescript
13:01	sdegutis	,(defn correct-answer-for [q] (->> q (reverse) (apply str) (read-string) (name) (reverse) (remove #{\?}) (apply str) (read-string)))
13:01	clojurebot	#'sandbox/correct-answer-for
13:01	justin_smith	RedNifre: https://gist.github.com/noisesmith/db3b90abb6b9e5f7f282
13:01	sdegutis	(correct-answer-for "Will the Bears ever win the super bowl again? I mean, probably not, right?")
13:01	sdegutis	,(correct-answer-for "Will the Bears ever win the super bowl again? I mean, probably not, right?")
13:01	clojurebot	right
13:01	sdegutis	Best function ever.
13:02	sdegutis	,(correct-answer-for "Who's better at Clojure than rhickey?")
13:02	clojurebot	rhickey
13:02	sdegutis	touché clojurebot.
13:04	RedNifre	Wow, those macro expands look incomprehensible to me.
13:04	justin_smith	hey, I pprinted the second one
13:04	RedNifre	,(correct-answer-for "Which language should I use when I'm done learning Clojure?")
13:04	clojurebot	Clojure
13:04	RedNifre	hmkay.
13:05	RedNifre	,(correct-answer-for "Whazzap?")
13:05	clojurebot	Whazzap
13:05	justin_smith	RedNifre: usually the macroexpansion is irrelevant if the macro is well written and used properly, there's just the size gotcha, as I was mentioning, for the crazy ones
13:06	justin_smith	ones where a whole mini language is implemented in a macro
13:06	RedNifre	Yeah, I get that. You saved me from future "Hey, why is my jar so big?"-moments.
13:06	justin_smith	well, the expanded code shouldn't usually end up in the jar
13:06	justin_smith	and you can avoid aot too pretty easily
13:06	RedNifre	huh?
13:07	RedNifre	I thought macros always expand? Or can you compile them as function calls?
13:07	justin_smith	RedNifre: all you need in a jar is the clojure source.
13:07	RedNifre	hmmmm
13:07	justin_smith	the expansion happens at compilation, which in clojure happens during startup usually.
13:07	RedNifre	I thought that was unusual and you usually compile to java bytecode?
13:08	justin_smith	RedNifre: avoiding aot if possible is usually better almost always
13:08	RedNifre	That's surprising. Why?
13:08	RedNifre	What's the advantage of a jar full of source code other than the jar size?
13:09	justin_smith	when you aot compile you can end up in a state where the source code conflicts with the byte code on disk
13:09	justin_smith	wacky scenarios like two classes with the same exact name that are not identical
13:10	justin_smith	and one extends the protocol you are using and the other does not
13:10	justin_smith	most of it comes down to caching issues I think, since laoding byte code and loading the source are two equally valid ways to get the same ns
13:12	OscarZ_	anyone familiar with cemerick/friend ring auth library?
13:13	sdegutis	Good morning.
13:14	justin_smith	RedNifre: also, when you deploy a library, to compile your byte code means you tie your user to the exact library code you developed with, which can interfere with the correctness of their own code
13:15	justin_smith	so while aot in an app is debatable (I'd argue minimize the amount of code that gets aot compiled as much as possible), you should strictly never aot compile libraries if you want anyone to ever use them
13:28	RedNifre	I understand that the JVM has no tail call optimization... but why do I have to use recur? Can't the compiler figure out that I want TCO whenever possible?
13:29	justin_smith	RedNifre: yes, but by requiring the usage of recur we can catch the otherwise common error that someone assumes TCO is applied where it can't be
13:29	justin_smith	RedNifre: this is a big problem in cl / scheme worlds where it is implicit
13:29	RedNifre	fair point.
13:30	justin_smith	because you don't even see the problem until you get a big enough stack at runtime
13:56	OscarZ_	i have a compojure route like this (route/resources "/static") and i'd like to secure this with cemerick/friend library.. i can use macro called "authenticated" to protect any function, but i guess in this case i dont have a function
14:52	sdegutis	OscarZ_: I've avoided Friend because its API design didn't quite fit into my application. It's not hard to roll your own solution though.
15:39	justin_smith	I've avoided friend because I'm just too dumb to figure out how I should use it
16:05	sdegutis	Why is this returning nil?
16:05	sdegutis	,(re-matches #"\<h1\>" "<h1>foo")
16:05	clojurebot	nil
16:06	sdegutis	Help me #clojure, you're my only hope.
16:06	TMA	,(re-matches #"<h1>" "<h1>foo")
16:06	clojurebot	nil
16:07	TMA	,(re-matches #"[<]h1[>]" "<h1>foo")
16:07	clojurebot	nil
16:07	TMA	sdegutis: no idea. everything apparently does
16:08	sdegutis	,(re-matches #".\<h1\>." "foo<h1>bar")
16:08	clojurebot	"foo<h1>bar"
16:08	sdegutis	That almost works:
16:08	sdegutis	,(re-matches #".\<h1\>." "quux \n foo<h1>bar")
16:08	clojurebot	nil
16:08	sdegutis	But it ignores everything after the first newline.
16:08	TMA	,(re-matches #"\<h1\>" "<h1>")
16:08	clojurebot	"<h1>"
16:09	TMA	,(re-matches #"\_.*\<h1\>" "<h1>")
16:09	clojurebot	nil
16:09	TMA	(doc re-matches)
16:09	justin_smith	,(re-matches #"<h1>" "<h1>")
16:09	clojurebot	"([re s]); Returns the match, if any, of string to pattern, using java.util.regex.Matcher.matches(). Uses re-groups to return the groups."
16:09	clojurebot	"<h1>"
16:09	justin_smith	you don't need to escape anything in that re
16:09	justin_smith	and it needs to match the whole string, not just a substring
16:10	TMA	,(re-matches #"(.\|\n)*\<h1\>" "<h1>")
16:10	clojurebot	["<h1>" nil]
16:10	sdegutis	Oh.
16:10	TMA	,(re-matches #"(?:.\|\n)*\<h1\>" "<h1>")
16:10	clojurebot	"<h1>"
16:10	justin_smith	TMA: you don't need to escape < or >
16:10	justin_smith	,(re-matches #"<h1>\w+" "<h1>foo")
16:10	clojurebot	"<h1>foo"
16:11	TMA	justin_smith: yeah, i have read that when you told it before, it does not hurt either
16:11	sdegutis	Hmm, I'm going about this all wrong.
16:11	justin_smith	it hurts readability
16:11	justin_smith	,(re-matches #"<h1>(\w+)" "<h1>foo")
16:11	clojurebot	["<h1>foo" "foo"]
16:11	TMA	sdegutis: use (?:.\|\n)* instead of .*
16:11	sdegutis	Given a multi-line string, how can return all occurreeanncces of #"<h\d>" ?
16:12	sdegutis	I have no idea how to spell ocurances.
16:12	TMA	sdegutis: occurences
16:12	sdegutis	You sure? That doesn't look right.
16:12	sdegutis	ocurrances?
16:12	TMA	nothing does at the moment
16:12	justin_smith	there's also a flag to make . match newlines
16:13	TMA	sdegutis: I am patently sure there is no -a- in that word
16:13	sdegutis	I'm not so sure.
16:13	sdegutis	justin_smith: how do you specify that flag in a regex Clojure literal?
16:13	sdegutis	,#"foo"g
16:13	clojurebot	#"foo"
16:13	sdegutis	Hmm.
16:13	sdegutis	,#"foo" you suck
16:13	clojurebot	#"foo"
16:13	sdegutis	hahah clojurebot sucks
16:14	sdegutis	Oh!
16:14	sdegutis	(?m) at the beginning?
16:14	sdegutis	Yes!
16:14	justin_smith	,(re-matches #"(?m).*<h1>(\w+)" "\n <h1>foo")
16:14	clojurebot	nil
16:14	sdegutis	(re-find #"(?m)(<h1>)" "foo\nbar<h1>quux")
16:14	sdegutis	,(re-find #"(?m)(<h1>)" "foo\nbar<h1>quux")
16:14	clojurebot	["<h1>" "<h1>"]
16:14	justin_smith	sdegutis: hmm, worked in my local
16:14	sdegutis	Yay!
16:15	justin_smith	nice
16:15	TMA	sdegutis: there are two -r-s but still no -a-: http://www.merriam-webster.com/dictionary/occurrence
16:15	sdegutis	TMA: I'm not so sure.
16:15	sdegutis	"occurrence"
16:16	sdegutis	huh, yeah
16:16	sdegutis	weird.
16:17	sdegutis	Woo!
16:17	sdegutis	,(re-seq #"(?m)<h\d>" "foo\nbar<h1>quux<h2>")
16:17	clojurebot	("<h1>" "<h2>")
16:17	sdegutis	take THAT, clojurebot!
16:20	backnforth	hiberno
16:20	backnforth	Hey
16:20	backnforth	Should I use sequences or lists?
16:23	backnforth	Sorry.. I'm new to clojure.
16:23	TMA	sdegutis: it is a common misspelling (because there are other words like "happenstance" where there is a -stance and there is -currant (blackcurrant) with an -a-) -- the reason for the -e- is that in latin the verb is occurro, occurrere, occurri, occursum; with present participle occurrens [from the unprefixed curro, currere, cucuri, cursum there is english current, currency, course, ...]
16:24	TMA	backnforth: lists are a specific kind of sequences
16:24	sdegutis	backnforth: lists, always lists
16:24	sdegutis	backnforth: avoid anything that conforms to (sequence?), always use lists
16:25	TMA	backnforth: notwithstanding the advice of sdegutis, I would consider arrays or lazy sequences too, on a case-by case basis
16:25	sdegutis	,(map (juxt sequential? map? list? vector? seq?) [() [] #{} {} (lazy-seq)])
16:25	clojurebot	([true false true false true] [true false false true false] [false false false false false] [false true false false false] [true false false false true])
16:26	backnforth	Sequences are a multi dimensional list to my understanding. Although, yes I would prefer to use arrays.
16:26	sdegutis	,(map (juxt sequential? map? set? list? vector? seq?) [() [] #{} {} (lazy-seq)])
16:26	clojurebot	([true false false true false ...] [true false false false true ...] [false false true false false ...] [false true false false false ...] [true false false false false ...])
16:26	sdegutis	backnforth: see that clode
16:26	sdegutis	backnforth: clode is short for Clojure code. It's a shorthand way of saying "Clojure code"
16:27	backnforth	I don't understand. I'm new to lisp structured.
16:28	backnforth	But yes, there are other structures I could use.
16:29	TMA	backnforth: if you need to quickly prepend an item to a beginning of a sequence, use lists. if to the end, use vector, if you need random element access (give me the 3rd, give me the 7th, ...) use vector
16:29	TMA	backnforth: if the data might be infinite (like sequence of all primes) use lazy-seq
16:30	TMA	backnforth: if the computation is expensive and you might not need all the elements use lazy-seq
16:32	backnforth	I assume lazy-sequences have better jumps.
16:32	TMA	backnforth: and finally, when you need a set use a set, whereas when you need a key->value store use a map
16:33	backnforth	What are sets?
16:34	TMA	backnforth: #{} ... you represent whether an element belongs to/is contained in the set
16:35	TMA	backnforth: instead of list of visited nodes, you keep a set of them, so that you do not need to traverse the entire list every time to find out, whether a node was visited
16:36	backnforth	Ah
16:37	backnforth	I should read on sets.. How do I works with the values in a list.. I can't find anything about them in the clojure.org reference
16:40	TMA	backnforth: you mostly take the value out of the list and work with the value -- there is nothing magical with the value caused by it being (also) in a list
16:42	backnforth	I'm looking for syntax
16:42	TMA	backnforth: say you have a list of your friends, say Jo, Alex and Xi ... if you write the list of friends somewhere you still interact with the persons the same way as if there were no list
16:43	TMA	oh
16:43	TMA	conj prepends an element to a list
16:43	TMA	,(first '(a b c))
16:43	clojurebot	a
16:43	TMA	,(rest '(a b c))
16:43	clojurebot	(b c)
16:44	TMA	and you can use first and rest to get to the elements
16:44	TMA	,(conj '(a b c) 'd)
16:44	clojurebot	(d a b c)
16:45	TMA	to get to the b you can:
16:45	TMA	,(first (rest '(a b c)))
16:45	clojurebot	b
16:45	backnforth	How do I simply read the value? And how do I read the index?
16:46	TMA	in list there is no index
16:47	TMA	backnforth: I have shown you how to read the first and second element of the list.
16:47	justin_smith	backnforth: you can get an item by index with nth, but you can't find any info about the list (including index or anything else) from the item
16:47	sdegutis	TMA: i dont think lazy seqs are still recommended for infinite data
16:47	sdegutis	TMA: i think the new recommended approach is transducers
16:47	justin_smith	,(nth 3 [:a :b :c :d :e :f :g :h])
16:47	clojurebot	#error {\n :cause "clojure.lang.PersistentVector cannot be cast to java.lang.Number"\n :via\n [{:type java.lang.ClassCastException\n :message "clojure.lang.PersistentVector cannot be cast to java.lang.Number"\n :at [sandbox$eval121 invokeStatic "NO_SOURCE_FILE" -1]}]\n :trace\n [[sandbox$eval121 invokeStatic "NO_SOURCE_FILE" -1]\n [sandbox$eval121 invoke "NO_SOURCE_FILE" -1]\n [clojure.lang....
16:48	justin_smith	,(nth [:a :b :c :d :e :f :g :h] 3)
16:48	clojurebot	:d
16:51	backnforth	List test[:a :b :c]
16:51	backnforth	,(nth test 3)
16:51	clojurebot	#error {\n :cause "nth not supported on this type: core$test"\n :via\n [{:type java.lang.UnsupportedOperationException\n :message "nth not supported on this type: core$test"\n :at [clojure.lang.RT nthFrom "RT.java" 888]}]\n :trace\n [[clojure.lang.RT nthFrom "RT.java" 888]\n [clojure.lang.RT nth "RT.java" 854]\n [sandbox$eval169 invokeStatic "NO_SOURCE_FILE" 0]\n [sandbox$eval169 invoke "NO...
16:52	backnforth	list test [:a :b :c]
16:52	backnforth	,(nth test 3)
16:52	clojurebot	#error {\n :cause "nth not supported on this type: core$test"\n :via\n [{:type java.lang.UnsupportedOperationException\n :message "nth not supported on this type: core$test"\n :at [clojure.lang.RT nthFrom "RT.java" 888]}]\n :trace\n [[clojure.lang.RT nthFrom "RT.java" 888]\n [clojure.lang.RT nth "RT.java" 854]\n [sandbox$eval193 invokeStatic "NO_SOURCE_FILE" 0]\n [sandbox$eval193 invoke "NO...
16:53	backnforth	list test [:a :b :c] ,(nth test 2)
16:53	TMA	backnforth: saying "list test whatever" does not have any effect on clojurebot
16:53	backnforth	Was that the right syntax?
16:54	sdegutis	backnforth: that's closer to haskell
16:54	ddellacosta	&(let [test [:a :b :c]] (nth test 2))
16:54	TMA	,(let [variable [:a :b :c]] (nth variable 2))
16:54	ddellacosta	oh, guess lazybot no longer runs
16:54	clojurebot	:c
16:54	ddellacosta	,(let [test [:a :b :c]] (nth test 2))
16:54	clojurebot	eval service is offline
16:55	ddellacosta	yeah, thanks so much hiredman
16:55	ddellacosta	nevermind
16:55	TMA	,test
16:55	clojurebot	#object[clojure.core$test 0x45d4887d "clojure.core$test@45d4887d"]
16:55	backnforth	,variable
16:55	clojurebot	#error {\n :cause "Unable to resolve symbol: variable in this context"\n :via\n [{:type clojure.lang.Compiler$CompilerException\n :message "java.lang.RuntimeException: Unable to resolve symbol: variable in this context, compiling:(NO_SOURCE_PATH:0:0)"\n :at [clojure.lang.Compiler analyze "Compiler.java" 6688]}\n {:type java.lang.RuntimeException\n :message "Unable to resolve symbol: variabl...
16:56	backnforth	,test
16:56	clojurebot	#object[clojure.core$test 0x45d4887d "clojure.core$test@45d4887d"]
16:56	TMA	backnforth: test is a name, that is already predefined
16:56	backnforth	I like you, clojurebot.
16:56	TMA	backnforth: on the other hand, variable is not predefined
16:57	backnforth	Ok
16:57	TMA	that's why there is a difference when evaluating them
17:32	GroundhogTest	My speclj tests will not fail.
17:35	justin_smith	GroundhogTest: are you doing the classic (should [1] vector-of-1) thing and forgetting the =?
17:36	justin_smith	actually maybe that only happens in clojure.test
17:37	GroundhogTest	I don't think so. I was using (around [it] (with-out-str it)), though.
17:38	GroundhogTest	Removed that, added a throw to my first test, and finally got a failure
17:38	justin_smith	interesting
17:38	justin_smith	yeah, I just checked, should doesn't take multiple args like clojure.test/is anyway
17:41	GroundhogTest	Thinking about putting the around call back in to confirm, but hesitant to make my tests completely useless on purpose
18:55	backnforth	How do I create an incrementing for loop like for(i=0;i<n;i++) ... is it: for((range n n+4))
18:57	rhg135	my brain hurts from the lack of intent. I think that'd be like (dotimes [i 4] ...)
18:58	amalloy	rhg135: don't provice useless answers to useless questions. figure out how to get enough information that the question becomes useful
18:59	backnforth	I'm just looking to do a basic loop
19:00	backnforth	using some constant as a range
19:00	backnforth	... the reason for doing is to interact through a list to compare its values with some other value.
19:00	rhg135	amalloy: usually I would, but the sensible part of my brain is asleep
19:00	rhg135	or dead or stuff
19:05	backnforth	How would I iterate through some list, compare its values with some value, then put values into a new list?
19:05	backnforth	The program is to: take some value n, check the list if there exist some value n, then put the locations that n exist in the list into some other list.
19:08	backnforth	I really want to learn clojure
19:16	amalloy	backnforth: what do you mean, the locations? what is a location?
19:20	rhg135	probably indices
20:42	troydm	let's say I have character \space, how do I make Clojure print it in a form of \space instead of space character, e.g. unescaped form?
20:47	Malnormalulo	quote it?
20:47	Malnormalulo	,'\space
20:47	clojurebot	\space
20:48	Malnormalulo	nope nevermind that doesn't work for print. Hm, that's a puzzle
20:50	amalloy	,(pr \space)
20:50	clojurebot	\space
20:50	amalloy	don't use print for anything except like...honestly there are not a lot of good reasons to use print
20:51	amalloy	the pr family of functions is great for printing data readably and unambiguously, and print does a mediocre job of producing human-friendly text
21:02	troydm	amalloy: thx
21:02	troydm	also is there a way to attach comment to variable definition
21:02	troydm	when u defn function you can add description to it
21:03	troydm	but I was wondering if it's possible to add description to arbitary variable too
21:03	troydm	Common Lisp has this kind of functionality I think
21:07	Malnormalulo	troydm: def accepts doc strings before the value
21:07	troydm	,(def a "doc" 1)
21:07	clojurebot	#'sandbox/a
21:07	troydm	,(pr a)
21:07	clojurebot	1
21:08	troydm	ic, thx
21:08	Malnormalulo	,(meta (def a "doc" 1))
21:08	clojurebot	{:line 0, :column 0, :file "NO_SOURCE_PATH", :doc "doc", :name a, ...}
21:13	TimMc	amalloy: What do you mean? println is great when you want to print strings.
21:14	amalloy	okay true. if you have something that's already a string, print and friends are good
21:16	troydm	also I've deftype'd some type and I defn'd some mytype? function which is basicly (= (type %) mytype) is this correct way to handle checking if object is of particular type?
21:23	Malnormalulo	It should work, but you might consider using a protocol instead, if you've got a method whose behavior depends on its argument's type
21:25	Malnormalulo	*if you've got a function
21:25	Malnormalulo	(curse my hours every day spent in Java)
22:50	ajb-	Why is bit shift left output on the jvm different from the output in the browser?
22:50	TimMc	ajb: Different numerics between JVM and JS.
22:50	TimMc	Example?
22:51	ajb	,(bit-shift-left 53245 16)
22:51	clojurebot	3489464320
22:51	ajb	so that's the jvm, and the js output of `53245 << 16` is -805452285
22:53	amalloy	javascript doesn't have integers
22:53	amalloy	so a lot of things are wacky
22:55	TimMc	1 << 32 // 1
22:56	TimMc	,(bit-shift-left 1 32)
22:56	clojurebot	4294967296
22:56	TEttinger	,(unchecked-int (bit-shift-left 1 32))
22:56	clojurebot	0
22:57	TEttinger	ajb: I'd strongly distrust JS when it tries to do any bit twiddling
22:58	ajb	yeah, well I need to since I am trying to render reagent on the server and react requires a checksum for the dom
22:58	ajb	I wish I didn't have to do any of this in js
22:58	TEttinger	I'd check for any libs that can compute the checksum
22:59	TEttinger	there may be someone who did this already
23:03	TEttinger	not sure how easy it is to call JS from CLJS, but this might be port-able http://stackoverflow.com/a/3276730
23:03	ajb	in cljs it does <<, I'm trying to get the same behavior in clj
23:04	TEttinger	ah.
23:04	TEttinger	well cljs would be doing that on a float or double, I think, since JS doesn't have integers as amalloy said
23:05	kvey	js converts the number type to 32 bit ints for bitwise operations (via research)
23:07	TEttinger	,(unchecked-int (bit-shift-left 53245 16))
23:07	clojurebot	-805502976
23:08	TEttinger	looks like what you want, almost. the lower bits are off
23:09	TEttinger	,(Long/toHexString -805452285)
23:09	clojurebot	"ffffffffcffdc603"
23:10	TEttinger	that is not shifted over by 16...
23:10	TEttinger	,(Long/toHexString (unchecked-int (bit-shift-left 53245 16)))
23:10	clojurebot	"ffffffffcffd0000"
23:11	TEttinger	it looks like the shift filled the lower bits with garbage?
23:11	TEttinger	in the JS one
23:11	TEttinger	thanks kvey for the 32-bit tip
23:12	TEttinger	oh. herp derp me
23:12	kvey	welcome - ajb and I work together
23:13	TEttinger	,(let [b (Long/toBinaryString (bit-shift-left 53245 16))] [b (count b)])
23:13	clojurebot	["11001111111111010000000000000000" 32]
23:13	ajb	oh, derp
23:13	TEttinger	I think it may be outside 32 bits
23:14	ajb	I just forgot to apply the bit-or to the return value
23:14	TEttinger	ah ok
23:14	TEttinger	bit-or?
23:14	TEttinger	I was thinking bit-and
23:14	ajb	but thank you, uncheck-ing it made it work
23:14	TEttinger	ah ok! good
23:15	TEttinger	unchecked-XXX stuff is also pretty fast
23:15	TEttinger	it's using something very similar to what Java would output in the same set of calls with operators on primitives
23:15	kvey	thanks! - I'd tried uncheck-int'ing the parameters but not the return value haha
23:16	TEttinger	yeah, surprising that clojure on JVM doesn't have smaller sizes of bit-whatever ops
23:16	kvey	the unchecked-int should be what's padding the result with garbage like that right?
23:17	kvey	whereas int throws an exception
23:18	TEttinger	no, I don't think so
23:18	TEttinger	hm
23:19	TEttinger	,(unchecked-int 0xffff0001)
23:19	clojurebot	-65535
23:19	TEttinger	correct
23:19	TEttinger	,(unchecked-int 0x00000001)
23:19	clojurebot	1
23:19	TEttinger	,(unchecked-int 0xf00000001)
23:20	clojurebot	1
23:20	TEttinger	yeah, that last one truncated the bits above 32 correctly
23:21	TEttinger	unchecked casts are useful for when you want something to replicate java or possibly other languages' behavior
23:23	TEttinger	I think the garbage in the JS version (JVM had 16 0 bits where it had shifted over, JS has 16 random-seeming bits) was maybe the bit-or thing ajb mentioned and was a result of a later step?
23:23	TEttinger	so not actually garbage data, intentional just from a source I can't see
23:25	kvey	ah I see
23:25	kvey	makes sense
23:59	TimMc	,(Long/toBinaryString -805502976)
23:59	clojurebot	"1111111111111111111111111111111111001111111111010000000000000000"