#clojure – 2015-11-26

2015-11-26

00:29	kenrestivo	logging change?
00:29	kenrestivo	~java logging
00:29	clojurebot	java logging is clown shoes
00:33	arrdem	the bojth
00:39	tolstoy	How many story points for "Log when the user logs in?" Get out your cards!
00:48	arrdem	heh
01:42	didibus	I'm trying to create a map from a vector as such: [:a "a" :b "b"] would give me a {:a "a" :b "b"} is there a method for that?
01:44	scottj	didibus: (apply hash-map [:a "a" ...])
01:45	didibus	hey, hadn't thought of that
01:54	douglarek	, (apply hash-map [:a "a" :b "b"])
01:54	clojurebot	{:b "b", :a "a"}
01:55	douglarek	, (hash-map :a "a" :b "b")
01:55	clojurebot	{:b "b", :a "a"}
03:23	jonathanj	is there an enlive selector that matches a nonexistent element?
03:23	jonathanj	for example if i want to add a child to the "head" element, if it doesn't exist then i want to create it
03:23	jonathanj	it's not obvious how you achieve this with enlive
03:37	wafflejock	if anyone can tell me how to translate this to a terminal command (or just explain the steps of what's going on) I'd be grateful http://paste.ubuntu.com/13513071/
03:37	wafflejock	So far I tried but it appears my base64 encoded output is longer than the actual passwords in the DB
03:37	wafflejock	echo -n SECRETSALTtest \| sha1sum \| awk '{print $1}' \| base64
03:38	wafflejock	basically inherited this code and trying to figure out how I can verify the passwords using the current method but in another language
03:38	opqdonut	sha1sum outputs the sum as hex
03:38	opqdonut	passing that to base64 sounds weird
03:38	opqdonut	what's "encode" in that snippet?
03:39	opqdonut	oh it's probably https://github.com/clojure/data.codec/blob/master/src/main/clojure/clojure/data/codec/base64.clj#L230
03:39	wafflejock	just made a more full version of the paste and just sanitized the salt value http://paste.ubuntu.com/13513085/
03:40	jonathanj	ugh, learning about enlive is a painful process
03:40	wafflejock	think that's it yeah but I have a tough time reading clojure let me know if you need me to search for anything else int he code
03:40	jonathanj	the documentation is awful
03:40	opqdonut	wafflejock: something like "sha1sum \| awk '{print $1}' \| xxd -r -p \| base64" is what you want
03:41	opqdonut	wafflejock: you want to base64-encode the raw output of sha1, not the hexadecimal representation
03:41	opqdonut	wafflejock: xxd -r -p takes in hex and outputs binary
03:41	wafflejock	opqdonut: okay will give that a go thanks for the help
03:41	opqdonut	wafflejock: and even that might be wrong due to byte order issues
03:43	wafflejock	opqdonut: nope you got it, so this is doing a sha1sum which outputs hexadecimal then that goes to xxd that converts to binary then base64 encodes?
03:44	wafflejock	thanks again for the help too, wasn't likely I was going to stumble on that myself
03:44	opqdonut	wafflejock: yes, which is what the clojure code does too
03:44	opqdonut	no worries
03:52	jonathanj	argh
03:52	jonathanj	i can't figure out how to select a <head> element only when it doesn't exist with enlive
04:08	jonathanj	this can't possibly be the best way to insert a <link>, and a <head> if necessary, surely? https://pb.codehash.net/ec8a2b65ef2c4f83a3f82451d0d96000
04:42	muhuk	suppose you're doing a fold (or reduce) and what happens inside has not clear description, perhaps just massaging data structures. But you still want to call the function you pass something. I'm using folder/reducer as generic names. Do you have a better name for this thing? (suppose I define these functions within some letfn inside another fn)
07:07	visof	hi guys
07:15	the_nona1	hey
07:41	ainu	ciao
07:41	powered	how to make function f such that : (f [:a :b :c :d :e] 1 3 4) = [:a :c :d] ?
07:41	wmealing	later
07:42	justin_smith	,(map [:a :b :c :d :e] [1 3 4]) ; powered
07:42	clojurebot	(:b :d :e)
07:42	justin_smith	hmm...
07:43	justin_smith	,(map [:a :b :c :d :e] (map dec [1 3 4]))
07:43	clojurebot	(:a :c :d)
07:43	jeaye	justin_smith: How's that working?
07:43	justin_smith	,(map (comp [:a :b :c :d :e] dec) [1 3 4])
07:43	clojurebot	(:a :c :d)
07:43	justin_smith	,([:a :b :C :d :e] 2) ; jeaye
07:43	clojurebot	:C
07:44	jeaye	justin_smith: So vectors, when invoked, behave like nth?
07:44	powered	vector as a function, cool
07:44	justin_smith	jeaye: just like hash maps
07:44	jeaye	Handy.
07:44	justin_smith	well, hash maps are get as a function, and get on a vector does nth
07:44	jeaye	Right.
07:44	justin_smith	see also keywords and symbols which become get as functions
07:45	justin_smith	,('foo '{foo bar baz quux})
07:45	clojurebot	bar
07:46	justin_smith	jeaye: it can also lead to really weird results...
07:46	jeaye	Yeah, I've seen this sort. Never with vectors though.
07:46	justin_smith	,('foo nil :huh) - if you didn't know this was calling get
07:46	clojurebot	:huh
07:46	justin_smith	or - even weirder
07:46	justin_smith	,((get get get get) nil :wat)
07:46	clojurebot	nil
07:47	justin_smith	,((get get get get) "anything" :umm :wat)
07:47	clojurebot	:wat
07:48	justin_smith	get can be used as (fn [a b c] c)
07:48	justin_smith	(as long as a isn't ILookup)
07:58	phaseNi	@seen onlineperson
07:58	phaseNi	whoops
07:58	phaseNi	wrong channel
07:59	mavbozo	,(instance? clojure.lang.IFn [])
07:59	clojurebot	true
07:59	mavbozo	,(instance? clojure.lang.ILookup [])
07:59	clojurebot	true
08:00	mavbozo	(,satisfies? clojure.lang.IFn [])
08:01	mavbozo	,(satisfies? clojure.lang.IFn [])
08:01	clojurebot	#error {\n :cause nil\n :via\n [{:type java.lang.NullPointerException\n :message nil\n :at [clojure.core$instance_QMARK___4118 invokeStatic "core.clj" 144]}]\n :trace\n [[clojure.core$instance_QMARK___4118 invokeStatic "core.clj" 144]\n [clojure.core$find_protocol_impl invokeStatic "core_deftype.clj" 511]\n [clojure.core$satisfies_QMARK_ invokeStatic "core_deftype.clj" 544]\n [clojure.core$...
08:01	mavbozo	,(satisfies? clojure.lang.ILookup [])
08:01	clojurebot	#error {\n :cause nil\n :via\n [{:type java.lang.NullPointerException\n :message nil\n :at [clojure.core$instance_QMARK___4118 invokeStatic "core.clj" 144]}]\n :trace\n [[clojure.core$instance_QMARK___4118 invokeStatic "core.clj" 144]\n [clojure.core$find_protocol_impl invokeStatic "core_deftype.clj" 511]\n [clojure.core$satisfies_QMARK_ invokeStatic "core_deftype.clj" 544]\n [clojure.core$...
08:01	justin_smith	,(doc satisfies?)
08:01	clojurebot	"([protocol x]); Returns true if x satisfies the protocol"
08:02	justin_smith	mavbozo: I think the issue here is that IFn and ILookup are interfaces, not protocols
08:03	mavbozo	,(doc instance?)
08:03	clojurebot	"([c x]); Evaluates x and tests if it is an instance of the class c. Returns true or false"
08:04	mavbozo	so, something can be a instance of a interface
08:04	justin_smith	yes
08:08	mavbozo	,(satisfies? CollReduce [])
08:09	clojurebot	#error {\n :cause "Unable to resolve symbol: CollReduce in this context"\n :via\n [{:type clojure.lang.Compiler$CompilerException\n :message "java.lang.RuntimeException: Unable to resolve symbol: CollReduce in this context, compiling:(NO_SOURCE_PATH:0:0)"\n :at [clojure.lang.Compiler analyze "Compiler.java" 6704]}\n {:type java.lang.RuntimeException\n :message "Unable to resolve symbol: Col...
08:36	newbie75	for systems created with nodejs it is a rather common pattern to hotswap JS source files on a running server. this is also possible with Clojure, but I know that most folks are very concerned about security and Clojure apps usually come as jars
08:36	newbie75	is there anything that holds me from hotswapping Clojure code?
08:37	justin_smith	even with a jar deployment, you can still load code at runtime if you want things to work that way
08:37	noncom	yeah, i know, i actually did that already
08:37	noncom	but otherwise, why is not it so common in this community?
08:37	noncom	or is it?
08:39	justin_smith	noncom: in terms of knowing the code works, there's a lot less to go wrong if you can be sure the exact code that was verified on staging can be run on production
08:39	justin_smith	and with hot-swapping there's a lot more ways for that to go wrong
08:39	noncom	that seems to me so too. so the nodejs people are simply more reckless?
08:41	noncom	yeah, probably there's not much more to it..
08:41	Glenjamin	erlang is the only language i know where people really hot-swap in prod
08:41	Glenjamin	or maybe some lispers
08:41	Glenjamin	node & JS swapping in general is generally only a dev tool
08:42	justin_smith	Glenjamin: but for every dev tool, you'll find some dev impatient enough to try it on production
08:43	Glenjamin	and so they should, as long as they let us know how it went
08:43	Glenjamin	erlang has been hot-swapping code in prod for decades
08:43	noncom	because erlang simply does not care if anything fails
08:45	justin_smith	see also php, which also cares not (for different reasons)
08:45	justin_smith	sounds like a joke - but the reason is the program is restarted for every request
08:46	justin_smith	with mirage, the vm loads so fast you can load up a new vm instance for a request
08:46	justin_smith	as in, OS level vm
08:50	ane	java, or well, the jvm, also has had hot-swapping for ages
09:02	mpenet	prismatic/schema question anyone knows if it's possible to have custom err message when using "pred" (it must be generated from the result of the predicate actually)?
09:03	mpenet	since it catches everything it's currently not possible (the pred throws, and is caught by "schema" internals and thrown away...)
09:07	justin_smith	mpenet: what about using s/check instead of s/validate?
09:07	mpenet	I guess I ll have to implement the Schema protocol
09:07	mpenet	hmm didn't try but I dont' think it makes any difference, "pred" will return the same (and still swallow the exception)
09:08	justin_smith	mpenet: check isn't supposed to throw is it?
09:08	justin_smith	it just returns a true/false
09:08	justin_smith	mpenet: I use check when I want to report that something isn't expected, but continue anyway
09:09	justin_smith	mpenet: see, no throw, just an informative return value https://github.com/Prismatic/schema/blob/master/src/cljx/schema/core.cljx#L136
09:09	mpenet	yeah but it's not what I want, I need to get to the exception thrown by my predicate used with "pred", right not it just says "the pred foo errored" in short.
09:11	mpenet	The predicate basically compiles a string input (SQL like language) into an AST, and I need to get to that error so that I can show it to the user (it has line/col info etc).
09:12	mpenet	anyway, I think I know how to do this, but it feels a bit convoluted, I hope I am not reinventing a wheel here
09:14	justin_smith	mpenet: if a function assumes that it can report a state to the top level of the code via a thrown exception, is that really a predicate though?
09:15	mpenet	it's not, but I can change it to return a value, I don't think it makes any difference. the pred must return non nil, rest is ignored
09:15	mpenet	or maybe I am not using the right fn from their api, I ll re-check
09:16	justin_smith	mpenet: right, sounds like what you have shouldn't be a predicate, it should be a custom validator with custom error output
09:16	mpenet	yeah, that's also my conclusion
10:19	powered	is there a faster way to concatenate a whole bunch of strings together than : (reduce str coll) ?
10:20	muhuk	powered: use a StringBuffer maybe
10:24	justin_smith	powered: apply str will use a StringBuilder, which is faster than what reduce will do
10:25	justin_smith	powered: see here https://github.com/clojure/clojure/blob/clojure-1.7.0/src/clj/clojure/core.clj#L517
10:32	powered	apply str was more than 500 times faster than reduce str
10:33	justin_smith	wow, I knew it would be faster, but that's a LOT faster :)
10:33	justin_smith	powered: how many items were being combined?
10:33	powered	just 11408
10:34	powered	with about 250 characters per string
10:35	tdammers	reduce is forced to concatenate strings one at a time; str can use a hanoi towers style algorithm
10:35	tdammers	the difference is sth like O(n^2) vs O(n) or sth
10:36	justin_smith	tdammers: also, reduce is generating 11407 immutable objects, while apply str uses one builder
10:50	zacts	hi clojurists
10:51	zacts	how does clojure compare to haskell?
10:51	zacts	when would I want to use clojure, and when would I want to use Haskell?
10:51	zacts	Clojure
10:52	powered	clojure is more dynamic and practical, but I haven't used Haskell so I don't know
10:52	dnolen	zacts: Haskell has a very powerful type system
10:52	dnolen	this is going to have a big effect on the way you write programs
10:52	ane	they are two different beasts
10:53	dnolen	in terms of prioritizing value oriented programming however they are very much the same
10:53	ane	i agree, there's lots of common ideas
10:53	dnolen	zacts: other things, Clojure has a more complete full stack story as it has a good mature compile to JavaScript story
10:55	zacts	ok
10:55	zacts	I know I do find Overtone interesting (the music processing system for Clojure)
10:55	zacts	and I think it's more mature for this purpose than anything Haskell offers afaik
10:56	zacts	can you metaprogram clojure via lispy () syntax tricks?
10:56	zacts	I know that Haskell doesn't use parenthetical syntax
10:56	zacts	so perhaps clojure would lend itself well to certain metaprogramming techniques better than haskell would?
10:58	ane	being a lisp, that is a given
10:58	ane	someone wrote a structured haskell editor mode for Emacs, but it's a bit... wobbly
10:58	ARM9	clojure almost has common lisp meta programming (just missing custom reader macros)
10:58	ane	haskell is not a lisp, it's descended from ML and Miranda
11:10	justin_smith	zacts: clojure does runtime metaprogramming like lisp, though it's not as common in normal clojure code. haskell supports compile time metaprogramming via template haskell, but I don't think it has runtime metaprogramming
11:11	zacts	I see, neat
11:12	zacts	how is clojurescript coming along these days?
11:12	justin_smith	I use it at work, it's good - the toolchain is a little awkward to set up
11:13	zacts	ah ok nice
11:13	justin_smith	but it is definitely usable, and it is very easy to migrate functionality between server and browser (since of course the backend is jvm clojure)
11:13	zacts	oh nice
11:13	zacts	so Clojure and Clojurescript interop is pretty good for most common tasks?
11:14	justin_smith	zacts: figwheel makes cljs development pretty amazing - you have a clojurescript repl, and the code you do in the repl immediately takes effect in the running browser
11:14	zacts	nice
11:14	justin_smith	zacts: I don't know about "interop" - eg the way you can directly use js in cljs, or directly use the jvm in clojure
11:14	justin_smith	but they communicate nicely, and you can share or migrate code between them very reasily
11:49	ARM9	any reason why some? isn't some ?
11:49	ARM9	since every? is [pred coll]
11:51	dnolen	ARM9: some isn't a predicate
11:51	dnolen	that is, doesn't return boolean value
11:52	phaseNi	Does anyone know a good example of using aleph to create a line based tcp connection?
11:52	ARM9	some does return a boolean or nil
11:52	dnolen	,(some #{:foo} [:foo :bar])
11:52	clojurebot	:foo
11:52	dnolen	ARM9: ^
11:52	ARM9	you're right
12:08	juanjo	hi
12:08	juanjo	how can i replace the last newline of a string by a space?
12:08	juanjo	like trim-newline but adding a space
12:13	broquaint	juanjo: (clojure.string/replace "foo bar\n" #"\n$" " ")
12:14	perplexa	+
12:14	juanjo	if i want \n or and \r? the same that trim-newline does?
12:15	broquaint	Use moar regexp :) e.g #"[\n\r]+$" that could be fancier but it'll do the job
12:16	juanjo	thanks
12:16	juanjo	im really new to clojure
12:46	juanjo	im using enlive
12:53	augustl	when I run "lein uberjar", the next clojure.tools.nameslace.repl/refresh fails with errors about namespaces it doesn't find
12:54	augustl	anyone know why that might be? Is it related to aot compilation maybe?
12:58	justin_smith	augustl: yeah, if you move the uberjar out of the target directory, then use lein clean, then the next refresh should not get an error
12:58	augustl	thanks! Will try that
12:58	justin_smith	augustl: I think it's the cached compilation artifacts (class files and such) made by uberjar that cause the problem
12:58	justin_smith	of course if you don't move the jar before running lein clean you lose the jar
13:10	augustl	ah, right :)
13:41	hlolli	,(def map-with-fn {:a (fn [[x y]] (+ x y))})
13:41	clojurebot	#'sandbox/map-with-fn
13:41	hlolli	,((:a map-with-fn) [2 2])
13:41	clojurebot	4
13:42	hlolli	,(def map-with-values {:a [2 2]})
13:42	clojurebot	#'sandbox/map-with-values
13:42	hlolli	My question is, what is a good syntactic sugared way to apply functions from one map to values of another map that share the same keyword?
13:46	justin_smith	,(apply apply (map :a [map-with-fn map-with-values]))
13:46	clojurebot	#error {\n :cause "Wrong number of args (2) passed to: sandbox/fn--26"\n :via\n [{:type clojure.lang.ArityException\n :message "Wrong number of args (2) passed to: sandbox/fn--26"\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....
13:46	justin_smith	ergh
13:47	justin_smith	if your fn had just been plus that would have worked
13:47	hlolli	hmm
13:47	justin_smith	,(apply apply (map :a [{:a +} {:a [2 2]}]))
13:47	clojurebot	4
13:47	hlolli	,((:a map-with-fn) (:a map-with-values))
13:47	clojurebot	4
13:49	justin_smith	,((fn [[f & args]] (apply f args)) (map :a map-with-fn map-with-values))
13:49	clojurebot	#error {\n :cause "Wrong number of args (0) passed to: PersistentVector"\n :via\n [{:type clojure.lang.ArityException\n :message "Wrong number of args (0) passed to: PersistentVector"\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.AFn applyToHelper "AFn.java" 152]\n [cloj...
13:49	hlolli	well, Im seeing if I can make my code cleaner by storing functions in a map and call them with another map, each function of course expects different input type.
13:49	justin_smith	,((fn [[f & args]] (apply f args)) (map :a [map-with-fn map-with-values]))
13:49	clojurebot	4
15:15	kenrestivo	i have a trivial question: why was there a plushy cthulhu on the podium at the conj?
15:52	waamaral	also, where can I get one?
16:15	beaky	any reason to use lsits over vectors?
16:20	beaky	i guess lists are more efficient when i want stack-like behavior?
16:20	beaky	and lists are the way to go for macros
16:20	beaky	and thats it?
16:40	justin_s1ith	beaky: just about any clojure function that goes through a collection and generates results one by one will return a lazy-seq, which is like a list but lazy
16:41	justin_s1ith	beaky: often it's a question of what you had to do with the input - and often there's no strong reason to make a vector again later
16:45	beaky	wow my use of multimethods has gone out of hand
16:46	beaky	ive got multimethods dispatching via multimethods and invoking other multimethods
16:46	beaky	how do you limit use of multimethods
16:52	elvis4526	I'm pretty sure the answer is yes, but is a uberjar generated on one server can be used again on another server?
16:52	elvis4526	If the JRE is the same version & architecture
16:52	justin_s1ith	elvis4526: yes, and with very few exceptions, the OS shouldn't even matter
16:53	justin_s1ith	and most of the time you just need the JRE to be 1.6 or newer, no other restriction
16:53	elvis4526	that's even better, that's really cool thanks
16:53	justin_s1ith	versions don't need to match
16:53	justin_s1ith	oh man my nick got changed
16:54	justin_smith	much better
17:57	m1dnight_	Hmm, I finally decided to fix the cider warning that cider-nrepl is not installed but none of the fixes i found online work. I have added it as :repl in my profiles.clj file and even as :plugin, but I still get the warning in emacs.
17:58	m1dnight_	I have updated all my emacs packages and updated leiningen as well.
17:59	m1dnight_	(ERROR: CIDER's version (0.10.0-snapshot) does not match cider-nrepl's version (not installed). Things will break!)
18:07	justin_smith	m1dnight_: you need the cider-nrepl plugin (usually added through profiles.clj)
18:08	justin_smith	m1dnight_: can you share your profiles.clj on maybe refheap?
18:08	justin_smith	[/win 3
18:12	m1dnight_	I seem to have set it up atm.
18:12	m1dnight_	But now `cider-restart` is broken :<
18:12	m1dnight_	to the google-copter
18:14	m1dnight_	All those different version numbers are so confusing. Am I on 0.10 or on .2.12 or what?
18:14	m1dnight_	https://www.refheap.com/112118 <- profiles.clj
18:15	m1dnight_	lein repl gives me: REPL-y 0.3.7, nREPL 0.2.10
18:15	m1dnight_	but leiningen version is 2.5.3
18:16	m1dnight_	and according to clojars 0.10.0-snapshot is the latest.
18:20	m1dnight_	Or is this just a bug in the cider.el (or whatever it is)?
18:20	m1dnight_	Seems like it as it is an emacs-level error.
18:21	justin_smith	m1dnight_: leiningen and nrepl are two different projects
18:21	justin_smith	and cider is a third - cider requires both the others though
18:21	m1dnight_	okay
18:21	m1dnight_	so if I get it right, nrepl is a leiningen plugin?
18:21	m1dnight_	like lein-ancient
18:22	m1dnight_	so that can be upgraded seperately of all the rest.
18:22	justin_smith	no, cider-nrepl is a middleware for nrepl
18:22	m1dnight_	oh
18:22	justin_smith	nrepl is provided by lein, though cider might want lein to use a different version of nrepl
18:22	m1dnight_	But the error I get now in emacs is "CIDER requires Nrepl .2.12 (or newer) to work properly"
18:23	m1dnight_	I dont mind that, but what I do mind is that it really crippled my emacs. Somehow. Im guessing the newest cider package? Because C-c C-k is broken, `cider-restart` throws "wrong type argument: stringp, nil"
18:24	justin_smith	m1dnight_: package.el compiles el files to elc, but cider is not binary compatible between upgrades, so at the very least you have to delete all your old .elc files
18:24	justin_smith	you can optionally recompile them, that helps emacs start up faster, but it's not a requirement for things to work
18:25	justin_smith	s/binary-compatible/api-compatible
18:27	m1dnight_	I have versioncontrolled my entire emacs and setup to autoinstall on boot. so I just did that.
18:27	m1dnight_	Reinstalling everything as we speak :p
18:28	justin_smith	m1dnight_: you don't need to reinstall
18:28	justin_smith	in fact, reinstalling won't help
18:28	justin_smith	you need to delete the elc files
18:28	m1dnight_	well, reinstalling emacs == rm -Rf .emacs.d && git clone .emacs.d :p
18:28	m1dnight_	so that does help
18:29	justin_smith	oh, and no .elc files in your git?
18:29	m1dnight_	no
18:29	m1dnight_	okay lets see
18:29	justin_smith	ok, so that's just a roundabout way of deleting the elc files then :P
18:29	m1dnight_	it is :>
18:30	m1dnight_	still the error, though
18:32	m1dnight_	Oh, but it seems like it is meant to throw those.
18:32	m1dnight_	so all is well.
18:32	m1dnight_	now back to what I wanted to do an hour ago.. :p
19:43	ChristopherS	I'm confused about something and am having trouble finding info online. How can I run an application, interact with it in a repl while it's running, and also make changes to the source and have them update in real time? I feel like I've seen things that say Clojure can do this, but I'm having a lot of trouble actually figuring out how.
19:51	bhajana	ChristopherS: do you use leiningen?
19:53	rufoa	anybody familiar with cljs-ajax? It seems if I perform the same ajax.core/GET request several times in a row, only the first one actually causes an XHR to occur? is there e.g. memoization or something going on?
19:58	ChristopherS	bhajana: yep, I use leiningen!
19:59	justin_smith	ChristopherS: this doesn't require leiningen actually - you can start your program from inside a repl, and use (require some.ns :reload) to load the newest version of a namespace
19:59	justin_smith	though some editors have bindings to automate that based on the file you are editing
20:03	ChristopherS	That makes sense! So let's say I wanted to do something like add a route to an already running compojure server. How would I run the server to allow me to do that, and then how would I do that (load in the new changes without stopping the server)?
20:04	justin_smith	ChristopherS: when you pass the routes to the function that starts your server, pass in the var so that when you change the var it sees the new value
20:04	justin_smith	I assume you are either setting a handler in project.clj or using run-jetty ?
20:13	ChristopherS	Hmm should I be using run-jetty? I've been doing `lein ring server`, but I'm pretty new to this
20:15	rufoa	there's also http-kit which works like run-jetty
20:15	justin_smith	ChristopherS: with lein ring server, you set the handler function in your project.clj - that is the other option I mentioned
20:16	justin_smith	ChristopherS: so in your project.clj, where it refers to the handler, what you can do is change some-ns/handler-name to #'some-ns/handler-name and this will pass the var to the http server, so that new values are used when it is redefined
20:23	kenrestivo	there are no apropos vars on async-shell-command to make it stop throwing a window up every time it runs. i want it to run in the background, is there a hook i can use to bury it before it shows?
20:24	kenrestivo	oops wron channel
20:27	kenrestivo	what i was going to ask here is: is there any way to convert a nested map into a zipper? i.e. {:foo {:bar 1 :baz 2} ?
20:28	kenrestivo	it's hard to determine the answer to the predicates that zip/zipper requires in a nested map like that
20:29	justin_smith	kenrestivo: a good predicate is coll?
20:29	justin_smith	,(coll? [])
20:29	justin_smith	,(coll? {})
20:29	clojurebot	true
20:29	clojurebot	true
20:29	justin_smith	and then seq to get the individual entries, of course
20:36	kenrestivo	hmm ok will try
21:27	douglarek	, (= ((fn [x y] (keep-indexed #(if (not= 0 (rem (inc %) y)) %2) x)) [1 2 3 4 5 6 7 8] 3) [1 2 4 5 7 8])
21:27	clojurebot	true
21:27	douglarek	, (= ((fn [x y] (keep-indexed #(if (not= 0 (rem (inc %) y)) %2) x)) [1 2 3 4 5 6 7 8] 3) '(1 2 4 5 7 8))')
21:27	clojurebot	true
21:27	douglarek	, (= ((fn [x y] (keep-indexed #(if (not= 0 (rem (inc %) y)) %2) x)) [1 2 3 4 5 6 7 8] 3) '(1 2 4 5 7 8)))
21:27	clojurebot	true
21:28	douglarek	= can be used between seq and vec,
21:28	douglarek	amazing!
21:31	justin_smith	douglarek: it's called structural equality
21:38	douglarek	justin_smith: thanks, any detail ?
21:39	justin_smith	douglarek: I rich hickey talks about his reasoning for structural equality in one of his videos, I forget which one
21:39	justin_smith	my version of he summary is that when you have immutable data, often what you want to know is if the shape of two collections matches, even if the exact type and instances are different
21:40	justin_smith	douglarek: for example, you expect (int 4) to be equal to (long 4) - same contents, different classes, right?
21:42	douglarek	yeah,
21:43	douglarek	so '(1 2) will share same structure with [1 2]?
21:43	justin_smith	douglarek: not on a literal sense of existing in the same place in ram
21:44	justin_smith	but they obviously have equal elements in each place
21:44	justin_smith	just as (int 4) and (long 4) are equal, but are not referring to the same object
21:44	douglarek	justin_smith: ok, i must try to understand it
21:45	justin_smith	douglarek: if you have "the joy of clojure" in hardback, and I have the same edition in paperback, we still say we have the same book
21:45	justin_smith	because what's in them is the same
21:46	douglarek	very vivid
21:46	douglarek	is it a value equality
21:47	justin_smith	right - they are equal by value, despite having different identity and class
21:47	douglarek	justin_smith: thanks a lot, Every time you help me all about it
23:44	kenrestivo	stuart's talk on debugging was great, but he left out the most important debugging technique:
23:45	kenrestivo	"copy/paste the error message into google"
23:45	kenrestivo	i think that's how 99% of problems are solved
23:47	justin_smith	kenrestivo: I swear one of these days I am going to make a website with the most common clojure error messages and what they usually mean
23:55	elvis4526	You should - most exceptions i encounter when using Clojure aren't terribly useful on their own. In general, would core.typed help against NullPointerException? Is it worth it?
23:57	justin_smith	elvis4526: it seems pretty cool, I have not tried core.typed though. I have tried prismatic/schema which is useful for runtime assertions about the shape of data in your inputs / outputs