#clojure – 2016-04-03

2016-04-03

00:00	tolstoy	I don't know what "vectors with a namespace :node" means. Maybe just show a couple?
00:00	backnforth	ah
00:00	backnforth	ok
00:01	backnforth	, [someVector [:node [1], :node [4], :node [9]]
00:01	clojurebot	#<RuntimeException java.lang.RuntimeException: EOF while reading>
00:01	backnforth	, [someVector [:node [1], :node [4], :node [9]]]
00:01	clojurebot	#error {\n :cause "Unable to resolve symbol: someVector in this context"\n :via\n [{:type clojure.lang.Compiler$CompilerException\n :message "java.lang.RuntimeException: Unable to resolve symbol: someVector 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: som...
00:01	backnforth	something like that
00:01	backnforth	I wanted to the count of 3 for the count of :node
00:02	tolstoy	,(count (filter #(= % :node) [:node [1], :node [4], :node [9]]))
00:02	clojurebot	3
00:03	tolstoy	Something like that?
00:03	backnforth	gross
00:03	backnforth	use filter?
00:03	tolstoy	Heh. ;)
00:03	backnforth	its so alient to me
00:03	backnforth	alien
00:03	backnforth	i will look into it
00:03	backnforth	thanks
00:03	backnforth	wow, im learning so much so fast
00:03	backnforth	this is great
00:04	tolstoy	,(:node (frequencies [:node [1], :node [4], :node [9]]))
00:04	clojurebot	3
00:04	will_sm	I've been doing some clojurescript with figwheel and reagent for fun. What are some other cool Clojure tools/libraries I could look into?
00:05	tolstoy	Seems like you'd have to do some sort of filtering, but perhaps the worthies on this channel will figure out something more clever.
00:05	tolstoy	will_sm: Instaparse to design your own language.
00:05	tolstoy	Well, sort of, anyway.
00:24	sdegutis	Is there a way to combine dec and max-0?
00:25	sdegutis	I guess (comp (partial max 0) dec)
00:28	sdegutis	,(def dec-pos (comp (partial max 0) dec))
00:28	clojurebot	#'sandbox/dec-pos
00:28	sdegutis	,(map dec-pos [-2 -1 0 1 2 3])
00:28	clojurebot	(0 0 0 0 1 ...)
00:29	sdegutis	,(map dec-pos [0 1 2 3])
00:29	clojurebot	(0 0 1 2)
00:29	sdegutis	Yay!
00:30	justin_smith	not to be confused with dec-comp-pos-e
00:43	backnforth	wow
00:43	backnforth	filter wont include a map if its value is false
00:50	tolstoy	Huh. Clojure's pretty good at, uh, s-expressions. ;)
00:50	tolstoy	Read in some forms that reference forms you previously read in, and, boom: there's postwalk-replace all ready for you.
00:56	sdegutis	backnforth: filter with some? if needed then I guess
00:57	backnforth	i like it, its very simple and useful
00:58	backnforth	reminds me of grep
01:41	Lewis	,(some #{false} [false false false])
01:41	clojurebot	nil
01:41	makufiru	Hey all, I'm using the Blaze templating system, and I'm wondering if there's a good way to sort a #each?
01:41	Lewis	why?
01:41	clojurebot	why is startup slow is busy compiling the `for` macroexpansion
01:41	makufiru	sorry wrong channel
02:09	ridcully	Lewis: because false is not logical true
02:09	ridcully	,(doc some)
02:09	clojurebot	"([pred coll]); Returns the first logical true value of (pred x) for any x in coll, else nil. One common idiom is to use a set as pred, for example this will return :fred if :fred is in the sequence, otherwise nil: (some #{:fred} coll)"
02:09	ridcully	,(some (partial = false) [false false])
02:09	clojurebot	true
02:10	Lewis	ridcully: what does logicaly true mean
02:12	Lewis	,(some #{nil} [nil nil nil])
02:12	clojurebot	nil
02:12	ridcully	neither nil nor false
02:12	Lewis	I see
02:13	Lewis	ridcully: what book do you advise
02:13	ridcully	,(some (partial contains? #{false nil}) [1 nil false])
02:13	clojurebot	true
02:16	Lewis	,(some (partial #{false nil}) [1 nil false])
02:16	clojurebot	nil
02:16	ridcully	i read two: the joy of clojure and clojure applied. the first one is a little tougher to chew and the second one is more practical
02:16	Lewis	,(doc contains?)
02:16	clojurebot	"([coll key]); Returns true if key is present in the given collection, otherwise returns false. Note that for numerically indexed collections like vectors and Java arrays, this tests if the numeric key is within the range of indexes. 'contains?' operates constant or logarithmic time; it will not perform a linear search for a value. See also 'some'."
02:17	ridcully	others suggested the "brave" book and the one from Carin Meier (spl?!) for beginners
02:17	Lewis	so joy of clojure and clojure applied are for intermediate?
02:18	Lewis	ridcully: i see.
02:19	ridcully	i'd say clojure applied is for you, if you have delivered software in other languages
02:19	ridcully	,(#{1 2 3} 1)
02:19	clojurebot	1
02:20	ridcully	the problem with using the set as a function here is, that it returns the element found - which is "the" false
02:21	ridcully	contains? on the other hand will tell you if the item is in the set
02:24	Lewis	ridcully: right i think i got it
02:31	Lewis	ridcully: what language are you coming from?
02:48	ridcully	Lewis: groovy on the jvm and c++, python otherwise
02:49	Lewis	i see
02:49	Lewis	ridcully: i dont know anything about the jvm
02:55	Lewis	,
02:55	clojurebot	#<RuntimeException java.lang.RuntimeException: EOF while reading>
02:55	Lewis	,(doc conj)
02:55	clojurebot	"([coll x] [coll x & xs]); conj[oin]. Returns a new collection with the xs 'added'. (conj nil item) returns (item). The 'addition' may happen at different 'places' depending on the concrete type."
09:12	ARM9	is there any decent way to leverage the jvm jit compiler to build programs at runtime?
09:12	ARM9	like say I've got some simpler functions that I'd want to combine into one function based on some input at runtime
09:13	ARM9	call it dynamic recompilation if you will
09:14	justin_smith	ARM9: the clojure bytecode compiler is always present during runtime in clojure
09:15	justin_smith	you don't need jit just to get something compiled
09:16	justin_smith	the jit is not predictable like that - it decides which bytecode it thinks should be inlined into machine code, and it has its own criteria. If you know exactly what should happen, do it yourself, and don't try to coerce the jit to do it.
09:18	ARM9	yes, and what I wanted to do is build a program at runtime that runs and (very likely) gets compiled by the jit to native code
09:20	justin_smith	ARM9: if you want the JIT to happen predictably there's a LOT to learn - there is no "compile this with jit" command. It looks at how frequently the code is called, the size of the method, the specific optimizations it knows how to do, the most common code path...
09:21	ARM9	I know how the jit works
09:21	justin_smith	ARM9: OK, have fun then
09:21	justin_smith	you can compile byte code at runtime in clojure. The JIT decides what to compile and how. That's your answer.
09:22	ARM9	yes and what I'm looking for is how to compile byte code at runtime
09:22	justin_smith	ARM9: by defining something
09:22	justin_smith	ARM9: every time you evaluate a clojure expression, it is compiled
09:22	Empperi	oh god I'm going nuts with boot soon
09:22	Empperi	I love the concept but man
09:23	Empperi	right now I just can't get my cljs compilation to end up into the target path I want it to
09:23	Empperi	yes, I know about the foo.cljs.edn thingy
09:23	Empperi	but it just doesn't read it apparently
09:23	justin_smith	ARM9: so if you can get fn or defn to run at runtime (likely using eval), then you're done, that's how it works.
09:23	Empperi	feels like only thing I can get to work properly is the stuff I define myself...
09:24	justin_smith	ARM9: the hard part is doing it in such a way that the JIT will be able to help you at all. Especially with idiomatic clojure code.
09:37	ARM9	right, fortunately for me I don't need it to be idiomatic
09:37	ARM9	like I said I just need some pointers on leveraging the jvm from clojure if at all possible, instead of writing my own jit
09:37	justin_smith	,(defn compile-a-thing [] (eval '(fn [])))
09:37	clojurebot	#'sandbox/compile-a-thing
09:38	justin_smith	that compiles bytecode every time it is called
09:38	justin_smith	you'll essentially be writing a macro definition, wrapped in eval
09:38	ARM9	that's good, I'll keep playing with eval then
09:38	ARM9	cheers
09:38	justin_smith	,(= (compile-a-thing) (compile-a-thing))
09:38	clojurebot	false
09:38	justin_smith	new one each time
11:12	sdegutis	bbl
11:13	liceoprova	ciao
12:42	justin_smith	java 9 will have a repl (!) http://www.pixelstech.net/article/index.php?id=1459558345
13:06	awwaiid	fancy
13:12	sdegutis	back
13:16	ane	java 9 will have nice things
13:17	sdegutis	justin_smith: seems weird
13:17	sdegutis	ane: like what
13:20	ane	the G1 GC becomes the default
13:21	ane	also Jigsaw, which lets you break the JRE into smaller components so you can drop the stuff you don't need
13:21	ane	native JSON support... uh what else, units of measure (!)
13:40	sdegutis	ane: JSON sounds nice
13:41	sdegutis	ane: Jigsaw sounds useless with Clojure
13:41	sdegutis	ane: units of measure?
13:41	ane	actually I was confused, not units of measure (like in F#), but currency support
13:59	Glenjamin	Java 9 has the module system merged, but punted on version numbers :(
14:18	sdegutis	wha
14:20	Glenjamin	jars can now specify the packages they contain, and the ones they depend on
14:21	Glenjamin	but they can't specify any version constraints, and you can only have one unique instance of a module in play
14:21	Glenjamin	or at least, that's what I can infer from reading up on the topic
14:42	ane	that's stupid
14:42	backnforth	yes
14:43	backnforth	exactly what i was going to say about my understanding of map functions
14:44	shafire	:-(
14:46	justin_smith	it's an improvement of not representing dependencies in the language
14:46	justin_smith	*over not representing...
15:17	Lewis	hey
15:17	Lewis	https://gist.github.com/6ewis/dcd71252a1277ed8d7b94e391a04d124
15:17	Lewis	can someone explain to me why 2 is showed twice
15:18	justin_smith	Lewis: swap! retries if concurrent modification occurs
15:19	justin_smith	Lewis: this is why you should not put anything with important side-effects inside a swap! call
15:19	justin_smith	Lewis: so two threads overlapped when incrementing from 1 to 2, one of them retried
15:19	justin_smith	(or is it 2 to 3?)
15:22	Lewis	justin_smith: thanks. I don't get it though...
15:22	justin_smith	Lewis: what do you think swap! does if two threads touch the same value?
15:22	Lewis	whats the difference between with the side effect and without
15:22	justin_smith	Lewis: the side effect will happen more than once when retries occur
15:23	justin_smith	Lewis: so if you put a file write, or a network connect, or a financial transaction, inside a swap!, it can be repeated
15:24	Lewis	justin_smith: can we start by the very basic..i use swap, what happen
15:25	justin_smith	Lewis: it reads the value stored, it executes your function, then it reads the value stored again
15:25	justin_smith	Lewis: if the value has changed, it runs your function over, but with the new value as input
15:25	justin_smith	Lewis: this is repeated until the same value is read twice, in every call to swap!
15:26	justin_smith	Lewis: it is much easier to see this in practice if you use a function that calls (Thread/sleep) before returning
15:29	Lewis	justin_smith: ok I think i undestand the basics but i still dont get whe i use swap multiple times why its different with sideeffects. let me think about it
15:37	Lewis	justin_smith: what's your favorite clojure editor?
15:44	cwgem\|mac	Lewis: I'd recommend looking over http://dev.clojure.org/display/doc/Clojure+Tools and picking one out. It's going to depend on what sort of needs you have and what you expect out of your editor (also what OS you're on)
15:45	sdegutis	bbl
15:45	Lewis	cwgem\|mac: im using lighttable and i can't get it to evaluate results
15:45	Lewis	"failed to open path
15:47	cwgem\|mac	Lewis: might want to ask around in #lighttable as that's where I'd expect more help from
15:47	Lewis	cwgem\|mac: its ok ill try something else
15:49	justin_smith	Lewis: if there's no side effects, nobody but the CPU cares that your function ran twice. With some kinds of side effects, (like running a monetary transaction or launching a weapon), doing the thing twice can be a problem
15:49	justin_smith	even doing the same file write twice can break things
15:51	cwgem\|mac	Lewis: yeah as I mentioned you should take a look at the wiki page and see what's easiest to setup and work with that. I like Light Table but it's a bit different in how it handles the overall process than something like eclipse or netbeans
15:52	justin_smith	also, light table has bugs that will lose all your work when it crashes - for some people that's a deal breaker in an editor
15:54	Lewis	justin_smith: cwgem\|mac ill look at vim
15:55	justin_smith	if you don't mind paying for an editor, cursive has an excellent featureset
15:55	justin_smith	I use vim currently myself (I like that I can easily ssh to my work box and work on the exact set of files I had last been looking at, with the help of tmux)
15:56	cwgem\|mac	justin_smith: any bug reports etc on the Light Table crashing issue? Trying to find something like that in their issue tracker
15:57	justin_smith	cwgem\|mac: sorry, it was anectdotal but I considered the source reliable (person I know from a local meetup)
15:57	cwgem\|mac	justin_smith: I personally think I might put it on hold for a bit as it's a bit weird getting koans to work with it
15:58	justin_smith	cwgem\|mac: I guess you could see what happens if you do a bunch of work without saving, then run kill -9 to force it to close - emacs or vim would have a file containing most or all of your work up to the point of that crash
15:58	justin_smith	(as would most other sensible editors I think, but those are the ones I have experience with)
16:04	Lewis	justin_smith: i use tmux/vim(yadr) im attempting to set up vim fireplace but it has a bunch of crazy dependencies
16:04	cwgem\|mac	Hmm Cursive looks interesting
16:06	rhg135	The good thing with it too is that it encourages doing the right thing
16:06	Lewis	https://github.com/guns/vim-clojure-static , how do you install it with vundle justin_smith
16:06	Lewis	rhg135: i also heard it makes easy to debug
16:06	justin_smith	Lewis: interesting - I use the vim-sensible package
16:07	rhg135	Debugging async code, pfft
16:07	Lewis	rhg135: talking about cursive*
16:07	justin_smith	Lewis: I added pathogen as an autoload, then I checked out vim-clojure-static in my bundle directory
16:07	justin_smith	Lewis: that doesn't get your fireplace though, that's just a pre-req
16:07	Lewis	justin_smith: right that's a dep
16:08	justin_smith	so you can get pathogen.vim as a single file, put that in the autoloads dir, then clone vim-clojure-static in the bundle dir, and it just worked for me
16:09	rhg135	The only reason I'm using it is because java
16:09	justin_smith	well, plus the pathogen.infect or whatever that is in the vimrc
16:10	rhg135	I'm writing public domain code anyway. Licensing is not an issue
16:11	justin_smith	rhg135: wow, not just open source, but full public domain?
16:11	rhg135	Yeah
16:11	Lewis	justin_smith: I'll try
16:11	rhg135	Feel the freedom
16:12	Lewis	justin_smith: so pretty much installing pathogen
16:12	Lewis	:)
16:12	Lewis	lol
16:12	cwgem\|mac	Well, it's still Java that has to run it, so there's only some freedom
16:12	rhg135	Using copyleft to keep people honest seems complicated
16:12	noethics	why was the jvm chosen for clojure
16:12	justin_smith	we can avoid having to think about javac at least (most of the time)
16:12	noethics	easy?
16:13	justin_smith	noethics: widely available, large standard library
16:13	noethics	ok
16:13	noethics	stdlib makes sense i guess
16:13	justin_smith	there's some nice advantages - as anyone that has deployed both ruby and clojure to a server could probably tell you
16:14	cwgem\|mac	Not only that but dealing with the annoying stuff like threading that the JVM does all over again isn't exactly fun
16:14	noethics	like what
16:14	justin_smith	noethics: repeatable builds - not needing a clean slate wipe of an entire system to reproduce a build environment
16:14	justin_smith	the fact that a deploy can be a single file uploaded, and that can just run
16:14	noethics	justin_smith, what are you comparing this to
16:15	justin_smith	noethics: ruby
16:15	noethics	most things fall into what you're talking about
16:15	noethics	oh
16:15	noethics	of course :P
16:15	noethics	i get you
16:15	justin_smith	I did say ruby above, right?
16:15	noethics	yeah
16:16	noethics	i'm not sure i really understand what you mean actually
16:16	noethics	given that both ruby and clojure need vms
16:16	justin_smith	but the existence of jars containing your deps (uberjars, fat jars, whatever you want to call them), is simpler to deploy than other things I've seen or tried. Also having version management that never requires global installs (and therefore doesn't require vms or sandboxing for basic day to day dev)
16:17	justin_smith	noethics: with ruby, you end up needing to worry about library versions, ruby version, and these typically are global installs
16:17	noethics	ok
16:17	backnforth	justin_smith, what if they're java dependencies?
16:17	justin_smith	not to mention native code dependencies (which are fairly common)
16:17	noethics	if this is interesting to you you might consider go :P
16:17	justin_smith	backnforth: you can pack them into the same jar with your code, and there is no need for a global install
16:18	backnforth	justin_smith, interesting
16:18	noethics	you compile a single binary and deploy that
16:18	noethics	no vm required
16:18	justin_smith	noethics: this is not the only reason I like clojure, but yes I hear go does these things somewhat sensibly too, haskell and ocaml as well (depending on tooling)
16:18	backnforth	noethics, Go is beautiful language and i have compared it to Clojure
16:18	rhg135	You act like a VM is a bad thing
16:18	noethics	backnforth, not sure about beautiful :)
16:18	justin_smith	noethics: the vm is a single file, and that can be part of the machine build and doesn't need to change
16:18	noethics	it is great though
16:19	rhg135	Well with jit
16:19	justin_smith	it's really not the pain point in any case I have seen
16:19	backnforth	noethics, harder to program with considering it's forced structures
16:19	backnforth	Go reminds much more of Python
16:19	backnforth	It is not a Lisp dialect
16:19	cwgem\|mac	You can toss a .war up to a tomcat server, versus getting your rails code up, running bundler, etc.
16:19	noethics	~_-
16:19	clojurebot	Excuse me?
16:20	noethics	is tomcat still used in new projects these days
16:20	noethics	in the clojure community?
16:20	justin_smith	noethics: elasticbeanstalk makes it easy to use tomcat as a target
16:20	noethics	$$$ though
16:21	justin_smith	noethics: I would never install it on my own machine, but it is easy to deploy to
16:21	justin_smith	typically I do a self hosting jar with aleph or http-kit though (for a web server)
16:21	noethics	ic
16:21	cwgem\|mac	Just a random example of something that can take a packaged file and deploy it
16:22	justin_smith	yeah, there are multiple containers you can trivially deploy to, when you can make a compatible jar
16:23	Lewis	I didn't get the talk about deployment, it's hardly difficult in rubyh
16:24	noethics	you have to program in ruby though
16:24	noethics	;)
16:24	cwgem\|mac	If you use JRuby you could tap into the Java deployment method
16:25	Lewis	huh
16:25	Lewis	deploying a rails app seems pretty straight forward to me
16:25	Lewis	justin_smith: could you get fire place to work> 'no live repl' on my end
16:26	cwgem\|mac	I'll say I don't hate ruby ( I work for a company that does a substantial amount of ruby deploys) and leave it at that since this is a Clojure channel ;)
16:27	ridcully	Lewis: have you started vim in the project root (where the .nrepl-port file is) or have you used `:Connect nrepl:///whattherepltoldyou` ?
16:27	noethics	fine
16:29	cwgem\|mac	Regarding why the JVM it's about what, 20 or so years behind it as a VM so a lot of issues have been solved (to some decent extent). Compare that to rolling your own VM and hoping to get it right.
16:30	noethics	i personally use a lot of go
16:30	noethics	there isn't any need for a vm
16:31	ane	eh, it has a runtime too
16:31	noethics	a far different thing than a vm :P
16:32	ane	maybe not a JIT compiler and all that jazz
16:32	ane	but it's still managed code
16:32	noethics	define managed
16:32	noethics	the distinction is that you're running machine code
16:32	ane	garbage-controlled, thread management?
16:32	noethics	the runtime just handles gc/scheduling
16:32	ane	"just"
16:32	noethics	?
16:33	ane	you shouldn't dismiss them like that
16:33	noethics	the runtime is also inlined into your binary
16:34	ane	sure is, that's what Clojure does as well
16:34	ane	but handling gc and scheduling isn't a minor thing
16:34	noethics	it inlines a full virtual machine :)
16:34	ane	no, it inlines the compiler
16:34	ane	the JVM runs that compiler
16:35	ane	if you want to compare Clojure to a completely VM-less language try Rust or C
16:35	noethics	i'm com[paring it to go because it's actually useable for the same problem space as clojure
16:35	noethics	they even have the same concurrency model!
16:35	ane	they don't
16:35	noethics	csp?
16:35	ane	clojure's innate concurrency model isn't CSP
16:36	noethics	because it runs on the jvm?
16:36	ane	no, that doesn't have anything to do with it
16:36	noethics	hmm
16:36	noethics	you mean outside of core.async?
16:36	ane	Clojure supports CSP with core.async, an external library
16:36	noethics	okay
16:36	noethics	what other method of doing concurrency is there?
16:36	noethics	java threads
16:36	noethics	?
16:37	ridcully	refs, agents, atoms
16:38	ane	yeah
16:38	ane	CSP is orthogonal to those approaches in some way
16:39	noethics	csp is more than just message passing but
16:39	noethics	maybe i'm not understanding how you mean
16:39	noethics	how would you define a concurrency model
16:40	cwgem\|mac	You don't have to have a VM persay, but with the JVM you have an abstraction around the different operating systems it supports, so (unless you use native OS code) you can hand someone a jar and mostly expect it to work
16:40	cwgem\|mac	Now compare that to a go binary built on linux handed over to a windows user
16:41	noethics	yes you need multiple binaries
16:41	noethics	just like you have to rely that they have a jvm installed for their target operating system
16:41	noethics	go has some nifty cross compiling functionality out of the box though
16:43	cwgem\|mac	yeah but I can tell someone "go install java" faster than explaining how to setup cross compiling. What it comes down to is each solution has some kind of sacrifice. Which sacrifice are you okay with decides what you use.
16:43	noethics	"go install java" or "here let me cross compile it for you"
16:43	noethics	:P
16:43	noethics	"don't forget to set PATH"
16:44	noethics	i dream of a day that clojure moves away from the jvm
16:44	tolstoy	I wouldn't mind seeing it built on top of Swift.
16:44	cwgem\|mac	That would kill the ability for it to easily integrate into Java environments of which there are plenty
16:45	tolstoy	Maybe not "clojure moves away" but "clojure also available on LLVM, JS, and Java".
16:46	noethics	"clojure now comes with a legacy bytecode to llvm compiler and native llvm frontend"
16:49	Lewis	justin_smith: it seems to work now, i expected more though..I wish it was like javascript plugins that gives your line errors and all those goodies
16:49	Lewis	noethics: what do you prefer - go or clojure
16:49	noethics	as a language, clojure
16:50	Lewis	cwgem\|mac: ane, cwgem\|mac, noethics: what's a good ressource to learn more about what you guys just talked about: Vms, etc..I'm very ignorant on the topic
16:50	Lewis	noethics: for web apps
16:50	noethics	Lewis, i think it depends very much on the problem :P
16:50	noethics	i would almost always choose go because it's more enjoyable stack to work with
16:51	noethics	if i could write clojure for the go runtime i'd be insanely happy though
16:51	noethics	or anything really. i just don't really like having to lug around the jvm
16:52	tolstoy	I've used the JVM for so long, I don't recognize the tax anymore.
16:52	tolstoy	Install JVM, "java -jar myapp.jar", done.
16:53	backnforth	tolstoy, not all of us have used it for long
16:53	troydm	I've declared unbounded variable using declare
16:53	troydm	how do I check if a variable is bounded or not?
16:53	troydm	I've tried (bound? abc) but it doesn't works on unbounded variable
16:54	Lewis	noethics: I was debating between clojure and go for my next web project (a tough choice)
16:54	tolstoy	backnforth: Right! That's what I meant.
16:54	backnforth	(exist? abc)
16:54	noethics	Lewis, do you know both
16:54	backnforth	maybe, im not sure
16:54	Lewis	noethics: no
16:54	noethics	Lewis, do you know either
16:54	tolstoy	Lewis: Maybe Go on the server side, and Clojurescript for the client?
16:54	Lewis	noethics: i know go syntax
16:54	backnforth	,(exist? abc)
16:54	clojurebot	#error {\n :cause "Unable to resolve symbol: exist? in this context"\n :via\n [{:type clojure.lang.Compiler$CompilerException\n :message "java.lang.RuntimeException: Unable to resolve symbol: exist? in this context, compiling:(NO_SOURCE_PATH:0:0)"\n :at [clojure.lang.Compiler analyze "Compiler.java" 6688]}\n {:type java.lang.RuntimeException\n :message "Unable to resolve symbol: exist? in t...
16:54	troydm	backnforth: no such function
16:55	noethics	what tolstoy said there is a super good decision
16:55	noethics	but if it means you have to learn a new language (or 2)
16:55	noethics	then weigh what is more important :P
16:55	tolstoy	noethics: I've wanted to do that on a project, but had no time to learn Go.
16:55	Lewis	tolstoy: I chose clojure because of reagent but I'm not looking forward to all those bad complain I hear about the JVM
16:55	noethics	completing the project, or learning said languuages
16:55	troydm	when I try bound? it gives me CompilerException java.lang.ClassCastException: clojure.lang.Var$Unbound cannot be cast to clojure.lang.Var
16:55	backnforth	guys, sorry to cut off the conversation, but can someone answer my question in #clojure-beginners please
16:55	backnforth	thanks
16:56	cwgem\|mac	https://docs.oracle.com/javase/specs/jvms/se7/html/index.html Here's a link on the JVM in detail
16:56	noethics	Lewis, to be clear the jvm is GREAT
16:56	Lewis	backnforth: I didn't know there was a clojure for beginners
16:56	noethics	itt's just big and noisy
16:56	cwgem\|mac	Can search around for youtube for "JVM Architecture" or "JVM" in general as well
16:56	Lewis	cwgem\|mac: holy cow, i was asing for a small summary to bring me up to speed with all the JVM gbc vs golang way of doing things talk
16:57	cwgem\|mac	I'm not sure if anyone has really done that kind of talk before
16:57	Lewis	cwgem\|mac: the argument you guys just had?
16:58	noethics	i think go wins on the backend (personally) because deployment is like the easiest thing NA
16:58	Lewis	noethics: How hard is it in clojure?
16:58	noethics	whereas with clojure you're probably dealing with some jetty stack
16:59	noethics	or maybe not, ut then who knows what you're dealing with :D
16:59	tolstoy	One thing the JVM has going for it in a lot of deployments is that most people know how to monitor it.
16:59	Bronsa	troydm: you need to check on the var object, on on the var value
16:59	Bronsa	(bound? #'your-var)
16:59	tolstoy	Tools to monitor the JVM can be independent of the app the JVM is running. (Basic ops, not business level, of course.)
16:59	noethics	like JVMTI and stuff
17:00	noethics	but tht degrades perf
17:00	noethics	you wouldnt use it in prod or anything
17:00	noethics	or maybe you would
17:00	Lewis	noethics: you're making me reconsider my choice (I hate that we have ten millions choices )
17:00	noethics	Lewis, why not both :P
17:00	Lewis	i only have one lifetime
17:01	cwgem\|mac	Lewis: here's a somewhat simplified explanation [PDF] http://www.cs.cornell.edu/courses/cs2112/2012sp/lectures/lec27-12sp.pdf [PDF]
17:02	noethics	Lewis, i think clojure is going to be easier to learn fwiw
17:02	noethics	go's syntax is simple but there are a lot of gotchas
17:02	tolstoy	Not too bad: https://en.wikipedia.org/wiki/Java_virtual_machine
17:02	noethics	specially with scoping and concurrency
17:02	Lewis	noethics: i learned goland pretty quickly
17:03	Lewis	well the basics
17:03	noethics	yeah P: but that's not where the trouble begins
17:04	noethics	another thing people stuggle with in go is lack of generics
17:04	noethics	everything you do is extremely adhoc and i think you need to understand that mindset to have a good time with go
17:04	ridcully	troydm: that should be (bound? #'abc) ?
17:04	noethics	in clojure you're free to do a lot of things
17:05	troydm	ridcully: hmm, let me think
17:05	Lewis	noethics: https://gist.github.com/6ewis/8bc789a14a46b921c16e
17:06	noethics	Lewis, decodeResponse should be a map[string]interface{}
17:06	noethics	but come to #go-nuts if you want to talk about it
17:06	noethics	:P
17:06	ridcully	hmm that's what Bronsa said already... didn't see
17:08	Lewis	cwgem\|mac: thanks, tolstoy: thanks ill check it out
17:08	Lewis	noethics: no offense but go seems ten times easier, i pick it up in a day
17:08	Lewis	noethics: and actually did that exercise the same day
17:08	noethics	o im not offended at all :P
17:09	noethics	i think you will see what i mean
17:09	noethics	maybe not
17:09	noethics	Lewis, note the things i said were problems in go
17:09	noethics	you have 0 concurrency and very ltitle scoping here :)
17:09	Lewis	cwgem\|mac: are you from cornell?
17:10	cwgem\|mac	Lewis: No I just happened to come across it and found it somewhat reasonable in content :P
17:10	Lewis	noethics: how complicated scoping can be if you're coming from ruby or javascript?
17:10	noethics	Lewis, about the same
17:11	Lewis	noethics: easier actually
17:11	noethics	??
17:11	Lewis	noethics: from what I read*
17:11	clojurebot	? is !
17:11	noethics	you have the obvious late binding problem in js but there are way more gotchas than in js
17:11	noethics	YouWillSee(TM)
17:11	Lewis	noethics: I haven't touched concurrency though. I have never had to deal with it yet but I'll have to on my next project
17:12	Lewis	noethics: shame on you, you really have noethics you put goland back on my mind. Now I'll have to think about what's the best path to take again
17:13	noethics	:)
17:14	cwgem\|mac	The answer is both paths at once :P
17:15	sdegutis	back
18:00	troydm	how do I make second argument to a function optional?
18:00	troydm	or rather I want to check if function that I get takes 2 or 1 arguments and act differently depending on that
18:03	justin_smith	troydm: you can define multiple arities to a function
18:03	justin_smith	but you can't check the arity a function accepts (now var for a defn, you can check that, and it will usually be useful - but more oriented to human readers)
18:03	troydm	justin_smith: I know but I get a function from calee as argument and I want to determine how many arguments that function can take
18:04	justin_smith	troydm: there's no way to do that
18:04	troydm	justin_smith: during runtime
18:04	justin_smith	troydm: you should be stricter about what functions someone can pass in, or expect them to pass args as a sequence and use apply
18:04	troydm	justin_smith: there is always a way (c) someone smart
18:04	justin_smith	troydm: trial and error, try/catch and when you get an arity error try something else? but that's bullshit, don't do it that way
18:05	justin_smith	troydm: there's no way to ask a function what argument count it takes and get a useful answer
18:07	justin_smith	troydm: you could look at what map does - it takes any number of colls and each becomes a source of one argument; or at swap! - it takes any number of args and passes them all to your swapping function after the value in the atom
18:07	troydm	justin_smith: found my answer http://stackoverflow.com/questions/17198044/how-can-i-determine-number-of-arguments-to-a-function-in-clojure
18:07	troydm	justin_smith: thx
18:09	justin_smith	troydm: so you are going to require that the var be passed in?
18:10	justin_smith	troydm: that means only supporting functions that are namespace level definitions
18:10	troydm	justin_smith: not sure what you mean, I just want my function to work with both (fn [a b] ) and (fn [a] ) arguments
18:11	justin_smith	troydm: the answer on that SO thread does not allow that
18:11	justin_smith	it only works for vars holding functions, not for functions - I mentioned the "require users to pass a var not a function" options above
18:12	troydm	justin_smith: I need it to work for vars holding functions only
18:13	justin_smith	troydm: OK
18:56	sdfgsadg	hello, could anyone give me a code review to see whether I'm writing idiomatic clojure, and what to fix/how to better model my data? I've tried #clojure-beginners but nobody has answered in several minutes
19:01	tolstoy	sdfgsadg Best to post a link and see if there are any takers.
19:05	sdfgsadg	Could I get a code review on this? https://bitbucket.org/pakoito/super8-clj/src/master/src/super8/ I want to know mostly whether the types I'm using to deal with mutable state in emu.clj are the correct ones, and whether the actual implementations are idiomatic cc @tolstoy
19:06	sdfgsadg	it's an emulator, so state is unavoidable. I'm porting from a terribly imperative codebase too, which doesn't help
19:06	sdfgsadg	thanks
19:08	sdegutis	brb
19:10	tolstoy	sdfgsadg: Looks fine to me. I guess some might say that you could hold all your state in an atom rather than refs. {:stack-point blah :program-counter blue} and so on.
19:10	sdfgsadg	train of thought was that given that only parts of it were updating at a time it need not block the whole map
19:11	tolstoy	sdfgsadg: Then on line 104, say, you can just (swap! state assoc :sp dec :pc (whatever)). But it's a bit unfair of me to say that given I don't know the code.
19:12	sdfgsadg	no, it's a fair point, I see what you mean
19:12	tolstoy	sdfgsadg: Well, that's a reasonable justification.
19:12	tolstoy	swap! doesn't lock for reads, I don't think.
19:13	sdfgsadg	are long let statements like the one in line 311 well regarded?
19:13	sdfgsadg	sometimes it feels like I could express all the logic save one return in it
19:14	tolstoy	For me, anyway, clarity is king. ;)
19:15	tolstoy	But you could do something like (let [{:keys [prog-c registers keys]} state] ....) destructure some of those things. But your way is easier to read.
19:18	tolstoy	Other than that, maybe you could put those dosync things behind functions, like (inc-program-counter state jump). Keep all the mutation in one place.
19:19	sdfgsadg	yup, I have to abstract that one
19:19	sdfgsadg	also collapse the =/!= opcodes
19:19	sdfgsadg	no need for duped code if it's just the operation that's different
19:20	tolstoy	Personally, I'm in favor of keeping things messy until one is nearly done, then seeing where the abstraction is appropriate. So I think the code looks great, in fact.
19:22	sdfgsadg	cool, many thanks :D
19:24	tolstoy	The only other thing I can think of is that a general pattern is that you pass in a state and get a new state back.
19:24	tolstoy	So, as you're processing each op-code, you'd do something like (loop [state init] (recur (process state next-opcode))) ....
19:25	tolstoy	If your emulator is just one code at a time, then maybe there's no need for mutation-in-place?
19:28	sdfgsadg	@tolstoy the actual op is a reduce, but I'm mutating the original map because performance, I guess
19:28	sdfgsadg	if I was to create a new state thousands of times per second it'd be too much
19:28	tolstoy	Ah. Well, there you go. Deviating from some common patterns for good reason. ;)
19:28	sdfgsadg	right now the emu is unbound
19:29	tolstoy	sdfgsadg: Well, but it's Clojure, so if you swap something onto a map, you're not creating a whole new state. It's fast.
19:29	sdfgsadg	you can see it in core, I'm actually passing back the same map
19:29	sdfgsadg	yeah it does the Persistance tree trick I guess
19:29	sdfgsadg	*trick as in the best part of Clojure collections :o
19:29	tolstoy	Yeah.
19:30	tolstoy	And then there's all that transient stuff I never use. But I don't see how dosync and so on are faster than just returning state with one key changed.
19:30	tolstoy	Sorry, that's sounds assertive: I just mean I really don't know. ;)
19:31	sdfgsadg	no, I'm learning, my assumption for going with that was multi-threading, which I won't implement because this is a learning project
19:32	sdfgsadg	and most emus/consoles are single threaded anyway
19:32	sdfgsadg	so no reason to descale it
19:32	sdfgsadg	*not to descale
19:32	sdfgsadg	I default to multi-threaded code because that's what I do day to day :P
19:33	tolstoy	Not that I know anything about how processors work, but you'd have to block anyway to switch context, etc, no?
19:33	sdfgsadg	you mean on the host or the emulated?
19:33	tolstoy	Well, hm.
19:34	tolstoy	I guess if you have multiple processes, each one seems single-threaded in and of itself (no shared memory).
19:34	sdfgsadg	the emulated isn't multi-threaded, it's ancient and just a step above a 7 segment display
19:34	tolstoy	So, each gets a "state". Can still do the loop technique.
19:34	tolstoy	Yeah.
19:35	sdfgsadg	yup, reducing on state makes sense to me, will change
19:35	tolstoy	Given the clarity of your code already, I'm hoping it be even simpler.
19:35	sdfgsadg	I have to return a vec or state/dirty, or reroll dirty inside the state again
19:36	sdfgsadg	dirty is not used by ops, so probably the vector/tuple return is the best option
19:45	sdegutis	back
19:46	sdegutis	what did i miss
19:48	tolstoy	sdfgsadg had a cool emulator.
19:50	sdegutis	oh cool
19:50	sdegutis	what did it emulate?
19:50	sdfgsadg	chip 8
19:51	sdfgsadg	I'm learning emulators and clojure at the same time, I'm almost done with CFTB&T and did the koans a while ago
19:51	sdfgsadg	so I started with the simplest one that had a decent reference
19:52	sdfgsadg	chip8, I'm like 60% done with the opcodes and will use play-clj for the UI, as libgdx is my jam
19:52	sdfgsadg	then move onto something with more meat, NES or GBC
20:09	sdegutis	WELCOME
20:13	sdegutis	justin_smith: Rappaport! I haven't seen you in ages! How have you been?
20:17	libertytrader	Hi I am trying to parse a single command line argument in clojure using cli tools
20:17	libertytrader	It is not working at all
20:17	libertytrader	here is my code:
20:17	libertytrader	(def cli-options
20:17	libertytrader	[["-t" "--test"
20:17	libertytrader	:id test]])
20:17	sdegutis	libertytrader: use gist
20:18	libertytrader	(if (= (:test (:options (parse-opts args cli-options))) true ) (println "true")(println "false"))
20:18	sdegutis	libertytrader: anyway i dont know what cli-tools is or how to use it
20:18	sdegutis	libertytrader: also, use gist
20:18	libertytrader	wtf is gist
20:18	libertytrader	and my code is small
20:18	TEttinger	http://gist.github.com
20:18	TEttinger	it's one of the many pastebins but most work allows viewing gist even if it blocks other pastebins
20:19	libertytrader	this is what I am trying use: https://github.com/clojure/tools.cli#example-usage
20:19	sdegutis	TEttinger: Rappaport! I haven't seen you in ages! How have you been?
20:19	libertytrader	Normally I would just try to use a repl... but how can i use a repl once i have launched app
20:19	TEttinger	eh?
20:20	sdegutis	TEttinger: You look taller than you used to be, did you grow?
20:20	sdegutis	TEttinger: Rappaport, you've got a new suit!
20:20	libertytrader	anyway here is my gist
20:20	libertytrader	https://gist.github.com/anonymous/699b95cd77d3c6503d44a1b67b0945cc
20:20	TEttinger	what's this?
20:20	sdegutis	TEttinger: now you say "I'm not Rappaport"
20:21	sdegutis	TEttinger: Rappaport, I don't remember you ever had glasses on?
20:21	sdegutis	(TEttinger: you're the straight man, you just say "I'm not Rappaport" whatever I say, ok?)
20:21	TEttinger	I've always had glasses on! Rattata, you remember this!
20:22	sdegutis	(Okay just say "I'm not rappaport" once)
20:22	sdegutis	(I set it up all wrong. It can still work though, just need this one line.)
20:23	TEttinger	I'm not rappaport
20:23	sdegutis	TEttinger: Rappaport, so you've gone and changed your name, too!
20:23	sdegutis	bu-dum tssh!
20:24	sdegutis	TEttinger: related: https://www.youtube.com/watch?v=F8yT24fnGJo
20:24	TEttinger	so confused
20:24	sdegutis	TEttinger: watch the video its 2 minutes
20:25	TEttinger	libertytrader: taking a look, is this code the ... in the block: (defn -main [& args] ... )
20:26	sdegutis	Well this has been a spectacular failure.
20:27	libertytrader	Tettinger: yes
20:28	TEttinger	what's wrong with it, libertytrader? are you getting an exception or bad behavior or what?
20:29	libertytrader	It always evaluates to false
20:29	libertytrader	even with --test passed in
20:30	TEttinger	have you tried just printing (:options (parse-opts args cli-options)) so you know what you're working with?
20:31	TEttinger	using = true is generally not needed
20:31	libertytrader	how do i print out a map
20:31	libertytrader	ive tried to no success
20:31	TEttinger	,(print {:options "like this"})
20:31	clojurebot	{:options like this}
20:31	TEttinger	or better
20:31	TEttinger	,(prn {:options "like this"})
20:31	clojurebot	{:options "like this"}\n
20:32	TEttinger	also clojure.pprint/pprint
20:32	TEttinger	,(clojure.pprint/pprint {:options "like this"})
20:32	clojurebot	#error {\n :cause "clojure.pprint"\n :via\n [{:type java.lang.ClassNotFoundException\n :message "clojure.pprint"\n :at [java.net.URLClassLoader$1 run "URLClassLoader.java" 366]}]\n :trace\n [[java.net.URLClassLoader$1 run "URLClassLoader.java" 366]\n [java.net.URLClassLoader$1 run "URLClassLoader.java" 355]\n [java.security.AccessController doPrivileged "AccessController.java" -2]\n [java.n...
20:32	TEttinger	,(use 'clojure.pprint)
20:32	clojurebot	nil
20:32	TEttinger	,(pprint {:options "like this"})
20:32	clojurebot	{:options "like this"}\n
20:32	TEttinger	same as prn here
20:34	TEttinger	(prn (:options (parse-opts args cli-options))) ;;; that's probably what you want
20:34	TEttinger	prn is print readably with newline
20:35	TEttinger	it prints vectors, maps, whatever you give it in a way that can usually be read back in as clojure code
20:35	libertytrader	I get unintelligible nonsense
20:35	libertytrader	{#object[clojure.core$test 0x61ff6a49 "clojure.core$test@61ff6a49"] true}
20:35	TEttinger	it's a map of some weird object to true
20:36	TEttinger	but that's not what I expected at all
20:36	libertytrader	I think the documenation for this api may be wrong
20:38	TEttinger	the code doesn't mention that class at all
20:38	TEttinger	ohhh!
20:38	TEttinger	,(doc test)
20:38	clojurebot	"([v]); test [v] finds fn at key :test in var metadata and calls it, presuming failure will throw exception"
20:38	TEttinger	you have :id test
20:39	TEttinger	it should be :id :test
20:39	TEttinger	test is a valid ID, it's just an existing fn in clojure.core so unlike most names it happens to have a valid value
20:39	TEttinger	:test is what that should be
20:40	libertytrader	thank you so much
20:40	TEttinger	libertytrader: that's an odd one, it only happened because test is already defined and the name was actually valid. for almost any other name it would have given an error!
20:41	TEttinger	glad to help!
20:42	libertytrader	it made a big difference in my daily sanity
20:42	TEttinger	heh
20:44	sdegutis	hi
20:44	sdegutis	how do u print fibbonaci help plz thnx
20:45	TEttinger	sdegutis: golf-off
20:46	TEttinger	,(take 5(map +(range)(iterate inc 1)))
20:46	clojurebot	(1 3 5 7 9)
20:47	TEttinger	hm.
20:47	TEttinger	there was a pattern for this
20:48	Lewis	what the heck is that
20:48	justin_smith	,(iterate #(juxt second (partial apply +)) 1)
20:48	clojurebot	#<ArityException clojure.lang.ArityException: Wrong number of args (1) passed to: sandbox/eval49/fn--50>
20:48	justin_smith	ergh
20:48	justin_smith	,(iterate #(juxt second (partial apply +)) [1 1])
20:48	clojurebot	#<ArityException clojure.lang.ArityException: Wrong number of args (1) passed to: sandbox/eval75/fn--76>
20:48	justin_smith	,(iterate (juxt second (partial apply +)) [1 1])
20:48	clojurebot	([1 1] [1 2] [2 3] [3 5] [5 8] ...)
20:49	Lewis	,(iterate inc 1)
20:49	justin_smith	sorry that took so many tries, I blame the hornitos
20:49	clojurebot	(1 2 3 4 5 ...)
20:49	Lewis	justin_smith: thank you for earlier by the way
20:49	Lewis	,(doc iterate)
20:49	clojurebot	"([f x]); Returns a lazy sequence of x, (f x), (f (f x)) etc. f must be free of side-effects"
20:49	justin_smith	np, glad I could help
20:50	sdegutis	TEttinger: WHOA you won
20:50	justin_smith	sdegutis: he didn't print fibbonaci, he printed odd numbers
20:50	sdegutis	justin_smith: now whatever I say, you just say "I'm not Rappaport"
20:50	sdegutis	justin_smith: Rappaport, how've you been? I haven't seen you in ages?
20:52	justin_smith	I am not the eponymous character behind a play originally staged at the seattle reertory theater in 1984
20:52	sdegutis	,(->> (iterate inc 1) (map + (range)) (take 5))
20:52	clojurebot	(1 3 5 7 9)
20:52	libertytrader	does anyone here use lighttable with vim bindings? Does anyone know how to make "/" for search and ":" for line number work
20:52	sdegutis	justin_smith: no no it was an old Willie Howard bit
20:52	sdegutis	justin_smith: now you be the straight man, I'll stand over here
20:52	sdegutis	justin_smith: Rappaport, what happened to you, you used to be a tall black guy now you're a short white guy?
20:53	justin_smith	I'm not rappaport
20:53	sdegutis	justin_smith: and you changed your name, too!
20:53	sdegutis	oh man
20:53	sdegutis	so good
20:54	sdegutis	libertytrader: did you see that?
20:54	sdegutis	haha!
20:57	libertytrader	what did i miss?
20:59	Lewis	libertytrader: vim
20:59	Lewis	I use vim and fireplace
21:03	TEttinger	,(map first(reductions(fn[[a b]_][b(+ a b)])[1 1](range 5)))
21:03	clojurebot	(1 1 2 3 5 ...)
21:04	TEttinger	love reductions
21:04	TEttinger	I can get it shorter...
21:06	Lewis	(doc nth)
21:06	clojurebot	"([coll index] [coll index not-found]); Returns the value at the index. get returns nil if index out of bounds, nth throws an exception unless not-found is supplied. nth also works for strings, Java arrays, regex Matchers and Lists, and, in O(n) time, for sequences."
21:06	libertytrader	is there a idiomatic way to say not equal in clojure?
21:06	libertytrader	instead of (not (= ...))
21:07	Lewis	the type signature is weird
21:07	Lewis	,(not= 1 2)
21:07	clojurebot	true
21:07	Lewis	libertytrader: ^^
21:07	justin_smith	Lewis: type signature?
21:08	justin_smith	,(nth [] 3 :something-else) ; you mean the arg list?
21:08	clojurebot	:something-else
21:08	sdegutis	i dont underst-- oh
21:09	Lewis	justin_smith: i mean the clojure type signature in the doc, what the args take and what it returns
21:09	justin_smith	Lewis: that's an args list
21:10	justin_smith	it doesn't describe what it returns at all - it just describes more than one arity
21:10	justin_smith	all it gives you for args is names
21:11	justin_smith	Lewis: it's saying that there are two argument counts for nth, I used the second one above
21:11	Lewis	justin_smith: for example check it out
21:11	Lewis	,(doc nth)
21:11	clojurebot	"([coll index] [coll index not-found]); Returns the value at the index. get returns nil if index out of bounds, nth throws an exception unless not-found is supplied. nth also works for strings, Java arrays, regex Matchers and Lists, and, in O(n) time, for sequences."
21:11	justin_smith	Lewis: yes I saw that the first time
21:11	Lewis	([coll index] [coll index not-found])
21:11	Lewis	can you explain it
21:11	justin_smith	it describes two lists of args
21:11	justin_smith	it does not describe the return value
21:12	justin_smith	you can either do (nth coll index) or (nth coll index not-found)
21:12	justin_smith	,(nth [1 2 3] 1)
21:12	clojurebot	2
21:12	Lewis	i see
21:12	justin_smith	,(nth [1 2 3] 42 :not-there)
21:12	clojurebot	:not-there
21:12	Lewis	i see thanks
21:14	justin_smith	,(defn foo "many ways of getting nil" ([]) ([a]) ([a b]) ([a b c]) ([a b c d]))
21:14	clojurebot	#'sandbox/foo
21:14	justin_smith	,(doc foo)
21:15	clojurebot	"([] [a] [a b] [a b c] [a b c d]); many ways of getting nil"
21:17	Lewis	,(iterate (fn [[a b]] [b (+ a b)]) [0 1])
21:17	clojurebot	([0 1] [1 1] [1 2] [2 3] [3 5] ...)
21:18	Lewis	,(first (iterate (fn [[a b]] [b (+ a b)]) [0 1]))
21:18	clojurebot	[0 1]
21:18	justin_smith	Lewis: yes, (fn [[a b]] [b (+ a b)]) is another way to write (juxt second (partial apply +))
21:18	TEttinger	,(map #(int(+(/(Math/pow 1.618 %)2.236)0.5))(range))
21:18	clojurebot	(0 1 1 2 3 ...)
21:19	TEttinger	justin_smith: not quite
21:19	justin_smith	TEttinger: wow, sneaky!
21:19	TEttinger	mine had a _
21:19	TEttinger	to allow the second arg of reduce fns
21:19	TEttinger	binet's formula, justin_smith
21:19	justin_smith	TEttinger: I was comparting to Lewis' function - which is identical to mine but written differently, not to your reduce
21:19	Lewis	,(take 10 (def fib (map (first (iterate (fn [[a b]] [b (+ a b)]) [0 1])))))
21:19	clojurebot	#<IllegalArgumentException java.lang.IllegalArgumentException: Don't know how to create ISeq from: clojure.lang.Var>
21:20	TEttinger	oh ok
21:20	justin_smith	Lewis: def returns a var, and that function never got called
21:20	justin_smith	,(take 10 @(def fib (map (first (iterate (fn [[a b]] [b (+ a b)]) [0 1])))))
21:21	clojurebot	#<IllegalArgumentException java.lang.IllegalArgumentException: Don't know how to create ISeq from: clojure.core$map$fn__4781>
21:21	Lewis	,(take 10 ((def fib (map (first (iterate (fn [[a b]] [b (+ a b)]) [0 1]))))))
21:21	clojurebot	#error {\n :cause "Wrong number of args (0) passed to: core/map/fn--4781"\n :via\n [{:type clojure.lang.ArityException\n :message "Wrong number of args (0) passed to: core/map/fn--4781"\n :at [clojure.lang.AFn throwArity "AFn.java" 429]}]\n :trace\n [[clojure.lang.AFn throwArity "AFn.java" 429]\n [clojure.lang.AFn invoke "AFn.java" 28]\n [clojure.lang.Var invoke "Var.java" 375]\n [sandbox$e...
21:21	Lewis	,(def fib (map (first (iterate (fn [[a b]] [b (+ a b)]) [0 1]))))
21:21	clojurebot	#'sandbox/fib
21:21	Lewis	,(take 10 fib)
21:21	clojurebot	#<IllegalArgumentException java.lang.IllegalArgumentException: Don't know how to create ISeq from: clojure.core$map$fn__4781>
21:21	justin_smith	Lewis: why is first preceded by a paren?
21:22	Lewis	,(def fib (map first (iterate (fn [[a b]] [b (+ a b)]) [0 1])))
21:22	clojurebot	#'sandbox/fib
21:22	Lewis	,(take 10 fib)
21:22	clojurebot	(0 1 1 2 3 ...)
21:22	Lewis	justin_smith: thanks
21:22	justin_smith	,(map first (iterate (juxt second (partial apply +)) [1 1]))
21:22	clojurebot	(1 1 2 3 5 ...)
21:26	Lewis	,(doc juxt)
21:26	clojurebot	"([f] [f g] [f g h] [f g h & fs]); Takes a set of functions and returns a fn that is the juxtaposition of those fns. The returned fn takes a variable number of args, and returns a vector containing the result of applying each fn to the args (left-to-right). ((juxt a b c) x) => [(a x) (b x) (c x)]"
21:27	Lewis	what does it mean in english?
21:27	justin_smith	,((juxt dec identity inc) 0)
21:27	clojurebot	[-1 0 1]
21:27	justin_smith	,((juxt name symbol keyword) "hi")
21:27	clojurebot	["hi" hi :hi]
21:28	Lewis	justin_smith: can you give me an example with each set of arguments given in the doc please?
21:28	Lewis	([f] [f g] [f g h] [f g h & fs])
21:29	justin_smith	,((juxt inc) 0)
21:29	clojurebot	[1]
21:29	justin_smith	,((juxt inc identity) 0)
21:29	clojurebot	[1 0]
21:29	justin_smith	do I need to do more?
21:30	Lewis	justin_smith: [f g h & fs])
21:31	justin_smith	,((juxt :a :b :c :d :e :f :g) {:a 0 :b 42 :c 33 :d 666 :e 420 :g 2 :f false})
21:31	clojurebot	[0 42 33 666 420 ...]
21:33	Lewis	justin_smith: what does fs mean
21:34	Lewis	& fs
21:36	sdegutis	,((fnil nil? 0) nil)
21:36	clojurebot	false
21:36	sdegutis	HAHAHA
21:37	Lewis	(doc fnil)
21:37	clojurebot	"([f x] [f x y] [f x y z]); Takes a function f, and returns a function that calls f, replacing a nil first argument to f with the supplied value x. Higher arity versions can replace arguments in the second and third positions (y, z). Note that the function f can take any number of arguments, not just the one(s) being nil-patched."
21:40	justin_smith	Lewis: it describes a rest-param http://clojure.org/reference/special_forms#fn
21:41	justin_smith	,((fn [a b & cs] cs) 1 2 3 4 5 6)
21:41	clojurebot	(3 4 5 6)
21:42	Lewis	i see
22:34	sdegutis	hi
22:34	sdegutis	wait brb
22:34	sdegutis	in like lots of hours
22:39	dpzmick	hi everyone, I'm running some benchmarks of some code on google's cloud. I expect some variablilty in my timings, but I'm getting some strange results. I have java code and clojure code. The java code tends to have much more consistent performance than the clojure code though. Both of them are being run through lein with the same profile. Both are doing similar things. Can anyone think of a reason I get much, much larger variance o
22:39	dpzmick	heres java: http://pasteboard.co/2Lr08NhF.png
22:40	dpzmick	heres clojure: http://pasteboard.co/2Lr2Adki.png
22:41	justin_smith	dpzmick: one guess (not seeing code) is that clojure puts more pressure on the short term gc
22:43	dpzmick	justin_smith: I know my code is putting lots of pressure on the gc
22:43	justin_smith	and the effects of gc are unpredictable (which leads to larger variance)
22:43	dpzmick	justin_smith: The java code has about the same logic, but it's not implementing that logic with first class functions and clojure structures
22:43	dpzmick	this makes lots of sense
22:44	dpzmick	so I may be able to tune gc flags to get some tighter values
22:44	justin_smith	maybe - or use more things like transients and transducers that can reduce gc usage
22:45	justin_smith	(if used apropriately, may or may not be helpful on your code, of course)
22:45	dpzmick	Won't help in this case unfortunately.
22:45	dpzmick	I'm just computing fiboancci recusively in this example
22:46	dpzmick	with some macro magic that turns the computation into a bunch of fork/join tasks
22:46	dpzmick	which is pretty rough on the gc
22:48	justin_smith	you could also look at numeric reflection - there's a flag to warn for that
22:49	justin_smith	because boxing is allocation, and you can usually eliminate it (at least in the tight spots) with the right annotations
22:50	justin_smith	dpzmick: http://insideclojure.org/2014/12/15/warn-on-boxed/
22:52	dpzmick	justin_smith: I've added type annotations already but perhaps I'm missing something, will try the flag as well
23:29	user_	maybe someone here can enlightenment me. I'm sorry for asking the same question a few times, but how do I count the amount of values a map in a vector holds?
23:34	user_	Not descriptive enough>?
23:46	TEttinger	user_: as in multiple maps in a vector, or a specific one?
23:47	TEttinger	,(count (apply concat [{:a 1 :b 2}]))
23:47	clojurebot	2
23:47	TEttinger	,(count (apply concat [{:a 1 :b 2} {:c 3 :d 4}]))
23:47	clojurebot	4
23:47	TEttinger	also
23:48	TEttinger	,(apply count [{:a 1 :b 2}])
23:48	clojurebot	2
23:48	TEttinger	,(apply count [{:a 1 :b 2} {:c 3 :d 4}]) ;; I believe this fails
23:48	clojurebot	#error {\n :cause "Wrong number of args (2) passed to: core/count"\n :via\n [{:type clojure.lang.ArityException\n :message "Wrong number of args (2) passed to: core/count"\n :at [clojure.lang.AFn throwArity "AFn.java" 429]}]\n :trace\n [[clojure.lang.AFn throwArity "AFn.java" 429]\n [clojure.lang.AFn invoke "AFn.java" 36]\n [clojure.lang.AFn applyToHelper "AFn.java" 156]\n [clojure.lang.AFn...
23:52	TEttinger	dpzmick: just curious, but I wonder if your actual task is similar to fibonacci in terms of a sequence generator. if it is, it might be worth it to calculate a closed-form solution OH GOD THIS IS TURNING INTO #haskell
23:53	TEttinger	but really closed form solutions are interesting stuff
23:54	dpzmick	TEttinger: yeah that would be the right way to do fib. I'm doing a benchmark to see how much of a speedup I can get for a low intensity, embarassingly parallel problem though
23:54	TEttinger	mmm.
23:54	TEttinger	pmap is probably not the best example of parallelism in Clojure
23:54	dpzmick	akin to the fork/join fib examples, but I have clojure macros taking (defn fib ...) and spitting out fork join code
23:54	TEttinger	ah ok
23:54	dpzmick	pmap is interesting, but it's not "control flow parallel"
23:55	TEttinger	yeah pmap is mostly useless in practice it seems, since it doesn't allow much manipulation of the number of threads etc
23:55	dpzmick	I'm trying to find easy ways to parallelize control flow (eg pure recursive functions) as a proof of concept
23:55	user_	(let [listInput [] listInput (conj listInput [{:paths [[:node 1, :cost 1], [:node 2, :cost 2]]},{:paths [[:node 2, :cost 1], [:node 3, :cost 2]]},{:paths [[:node 0 :cost 1], [:node 1, :cost 2]]}])] (print (count (:paths(nth listInput 1)))))
23:55	dpzmick	who knows if its actually useful. I found some paper saying that people generally use data parallel things much more often than task parallel
23:55	user_	TEttinger, I'd want count to return 2
23:56	TEttinger	well let's run it with the comma prefix
23:56	TEttinger	,(let [listInput [] listInput (conj listInput [{:paths [[:node 1, :cost 1], [:node 2, :cost 2]]},{:paths [[:node 2, :cost 1], [:node 3, :cost 2]]},{:paths [[:node 0 :cost 1], [:node 1, :cost 2]]}])] (print (count (:paths(nth listInput 1)))))
23:56	clojurebot	#error {\n :cause nil\n :via\n [{:type java.lang.IndexOutOfBoundsException\n :message nil\n :at [clojure.lang.PersistentVector arrayFor "PersistentVector.java" 158]}]\n :trace\n [[clojure.lang.PersistentVector arrayFor "PersistentVector.java" 158]\n [clojure.lang.PersistentVector nth "PersistentVector.java" 162]\n [clojure.lang.RT nth "RT.java" 853]\n [sandbox$eval121 invokeStatic "NO_SOURC...
23:56	user_	TEttinger, I tried so many techniques, very frustrating
23:56	TEttinger	oh of course
23:57	TEttinger	conj doesn't modify listInput
23:57	dpzmick	TEttinger: paper: http://dig.cs.illinois.edu/papers/StudyParallelLibraries.pdf
23:57	TEttinger	oh you redefine it nvm
23:57	user_	TEttinger, maybe a straight binding would have looked better
23:57	user_	TEttinger, I was suggested that a few weeks ago on irc lol
23:57	user_	.
23:58	user_	i tried so many variations
23:59	TEttinger	,(let [listInput [{:paths [[:node 1, :cost 1], [:node 2, :cost 2]]},{:paths [[:node 2, :cost 1], [:node 3, :cost 2]]},{:paths [[:node 0 :cost 1], [:node 1, :cost 2]]}] ] (print (count (:paths(nth listInput 1)))))
23:59	clojurebot	2
23:59	TEttinger	I think the conj was producing a different vector than you thought
23:59	user_	no way.
23:59	user_	i think it added a nil vector
23:59	user_	to the main vector
23:59	TEttinger	,(let [listInput [] listInput (conj listInput [{:paths [[:node 1, :cost 1], [:node 2, :cost 2]]},{:paths [[:node 2, :cost 1], [:node 3, :cost 2]]},{:paths [[:node 0 :cost 1], [:node 1, :cost 2]]}])] listInput)
23:59	clojurebot	[[{:paths [[:node 1 :cost 1] [:node 2 :cost 2]]} {:paths [[:node 2 :cost 1] [:node 3 :cost 2]]} {:paths [[:node 0 :cost 1] [:node 1 :cost 2]]}]]