#clojure – 2015-06-21

2015-06-21

00:00	zapho53	I have a function with a let binding followed by 2 function calls which add something to a database. Whichever way round I switch them only the last one executes.
00:01	amalloy	zapho53: they are both returning a lazy sequence, which you forget to force any elements from
00:01	zapho53	Both functions have a YeSQL <! return value.
00:02	zapho53	amalloy: Then why does 1 execute?
00:02	amalloy	because you return it, and whoever is above you in the call hierarchy happens to force it
00:03	zapho53	amalloy: How do I get both to execute?
00:03	amalloy	i mean there are other possible explanations and i don't know what this yesql thing is, but this is by far the most likely cause for the scenario you are describing, absent any code snippets to the contrary
00:04	amalloy	zapho53: try wrapping them both in (doall ...) to prove or disprove my supposition
00:04	zapho53	amalloy: Tried that once but maybe I screwed it up. Will try again.
00:05	amalloy	if that isn't the answer you will have to link to some actual code, or find someone who knows what yesql is
00:05	pranavrc	Hi. I'm having a little trouble with the syntax for unquote-splicing inside a macro. I've pasted the details here: http://pastie.org/10251103 Can someone suggest what might be wrong?
00:06	zapho53	amalloy: doall results in this error: clojure.lang.LazySeq cannot be cast to java.lang.Number
00:07	amalloy	zapho53: then we have fixed the problem you asked about, and advanced to some other error
00:07	zapho53	amalloy: Which is weird because both functions will execute the desired result if put last in the order.
00:08	amalloy	pranavrc: ` is shorthand for writing the tedious (list 'let ...) stuff you are doing by hand. you don't want to use both in most contexts
00:09	amalloy	you could either write `(let [~'time (now)] foo bar baz), possibly with some more quoting depending on what foo/bar/baz actually are, or (list `let ['time `(now)] `foo `bar `baz), possibly with less quoting that again depends on what foo/bar/baz are
00:14	pranavrc	amalloy, I can't use `foo `bar `baz there as is, because the ~@(list foo bar baz) component I've included is actually a different function call that returns a list. I just used a different function for brevity.
00:15	amalloy	okay, so it's `(let [~'time (now)] ~@(whatever))
00:16	pranavrc	amalloy, in which case I still get the illegalstateexception error for unbound unquote
00:16	amalloy	no you don't. you can't get that exception from the code i pasted, unless (whatever) by itself also throws that exception
00:17	amalloy	in which case, fix whatever
00:26	pranavrc	amalloy, alright, thanks!
00:26	amalloy	pranavrc: i suspect the reason whatever throws is you are trying to unquote stuff inside it, like @(whatever ~foo)
00:27	amalloy	which is not what you want. you have already unquoted the whole expression
00:27	pranavrc	amalloy, yeah, that was the problem.
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03:25	kwladyka	How clojure is developing during all this years? What can we estimate about job and projects in Clojure?
04:11	ttt_fff	how does one implement tuples in clojure?
04:11	expez	by using a vector
04:18	TEttinger	(inc expez)
04:18	lazybot	⇒ 1
04:19	TEttinger	yep, vectors already allow whatever for types, so you have the main advantage of tuples in a statically typed language right there already. and they're a single value, so that's the other use
04:31	rs0	also destructuring
04:49	mskoud	Hi there!
05:01	kaffeeboehnchen	Good morning. :) I have this macro: https://paste.xinu.at/dabljg/clojure When I call it I get a null pointer. test-auth is working with the data I am calling the macro with if I call it on its own. What am I doing wrong?
05:03	Chousuke_	is authed-header actual clojure code?
05:03	kaffeeboehnchen	Yes.
05:03	Chousuke_	how does the macro invocation look?
05:03	kaffeeboehnchen	it is a map looking like that: {:status 123 :body "hi"}
05:04	kaffeeboehnchen	(handle-request test-request other-fun)
05:04	Chousuke_	your macro is passing the symbol 'test-request to test-auth
05:04	kaffeeboehnchen	my goal is to call other-fun when authed-header does not have a specific status and give other-fun the same request.
05:05	kaffeeboehnchen	ah, ok
05:05	Chousuke_	why does this need to be a macro? :/
05:05	kaffeeboehnchen	I have no clue to do it otherwise.
05:05	kaffeeboehnchen	If there is a better way please tell me.
05:06	kaffeeboehnchen	other-fun will not always be other-fun by the way
05:06	kaffeeboehnchen	the function which should be called will change
05:06	Chousuke_	can't you just (if (check-status authed-header) blah (other-fun authed-header))?
05:07	amalloy	the easiest way to make this macro be a function is to change the defmacro to defn. it would be closer to working that way
05:07	Chousuke_	you can pass functions as arguments to other functions
05:07	kaffeeboehnchen	But doesn't it get evaluated the moment I pass it?
05:07	Chousuke_	evaluated?
05:08	Chousuke_	if you pass it in a variable, why does that matter?
05:08	kaffeeboehnchen	It only should be executed if authed-header has the status 202
05:08	Chousuke_	it won't be executed.
05:08	Chousuke_	it's just a function
05:08	kaffeeboehnchen	ok
05:09	Chousuke_	I'm still not sure if I understand your problem correctly
05:09	kaffeeboehnchen	Later I wanna call (handle-request request this-fun), (handle-request request that-fun), (handle-request request other-fun).
05:10	Chousuke_	yeah, that's just fine
05:10	kaffeeboehnchen	Ok. Thank you very much!
05:10	Chousuke_	I mean, if you do eg. (list + -), that won't actually call the + - functions
05:10	Chousuke_	you just get a list that contains them
05:10	kaffeeboehnchen	aaaaahh
05:46	ambrosebs	what's the current stance on Java 7 support in core/contrib?
05:47	ambrosebs	going away soon?
06:17	TEttinger	ambrosebs: I wasn't aware core/contrib was still around, tbh
06:18	ambrosebs	core+contrib
06:18	TEttinger	but unless clojure is specifically moving from 6 compat to 8 compat, I kinda wonder why they would do that
06:19	TEttinger	(did clojure stop supporting JDK6 and thus android?)
06:19	ambrosebs	good question
06:19	kwladyka	Can i discuss with somebody about Ring architecture? My goal is learn about architecture on this project.
06:22	kwladyka	first of all what determine to separate catalogs core/devel/jetty-adapter/servlet as root direcotries, not as src/* directories?
06:27	kwladyka	as i understand ring respository has 4 projects 1 one, why not 4 separater ring repository?
06:34	Jickelsen	I've included react-with-addons (from CDN) but (aget js/React "addons") returns nil. Any ideas?
06:49	kwladyka	ok, next step... i understand magic happens because of lein-sub library
06:55	crocket	clojure repl uses 600MB of RAM from the beginning.
06:55	crocket	How do I tame its memory usage?
07:03	kwladyka	so next... ring project use lein-sub and has :sub in profile.clj for subprojects, but this subprojects doesn't have main function or something like this. Also if i understand then run as casdace one by one, not paraller or... exatly opposite to cascade, because i am not sure how to interpratate "Should you need recursive behavior, consider Leiningen aliases or lein-cascade." and if not main functions inside... what exatly is running?
07:06	kwladyka	crocket, what do you mean clojure repl? "lein repl"? for me 1 136K memory
07:07	crocket	yes
07:07	crocket	lein repl
07:07	crocket	It uses 620MB of RAM inside cider repl which is essentially lein repl.
07:08	kwladyka	crocket, "lein repl" for me on windows get only 1 136k memory
07:09	kwladyka	maybe you interpret used memory by process in bad way if you running repl inside another application
07:09	crocket	I?
07:09	crocket	not me
07:09	clojurebot	I will never forgive that
07:10	kwladyka	mmm?
07:13	crocket	Look at http://imagebin.ca/v/25zcAKgAPHTq
07:14	crocket	lein repl ends up using 1GB
07:14	crocket	kwladyka, ^^
07:15	kwladyka	crocket, i relogin to IRC, i guess i miss something
07:19	TEttinger	kwladyka: crocket meant http://imagebin.ca/v/25zcAKgAPHTq
07:20	TEttinger	lein repl uses more or less RAM based on the project you're in, IIRC
07:20	TEttinger	since it does load the whole project to make it available, IIRC
07:23	kwladyka	my mistake, but still i have 200 MB or 250MB, I forgot :)
07:42	crocket	TEttinger, It is a very minimal leiningen project.
07:42	crocket	It only has 3 functions.
07:43	ambrosebs	how can I tell lein to never compile/test a file in my test path
07:43	TEttinger	then... just curious, how much free RAM do you have on your machine?
07:43	TEttinger	it's possible Java's gobbling up more than it currently needs in anticipation for later usage
07:44	crocket	TEttinger, 8GB of RAM and 13.5GB of swap.
07:44	TEttinger	is it swapping now?
07:44	crocket	no
07:44	crocket	The system currently uses 2.5GB of RAM in total.
07:45	crocket	And, swapping doesn't necessarily lead to HDD access as far as I know.
07:45	crocket	However, swapping is not desirable.
07:45	TEttinger	oh that could be why then, you have enough free that java thinks it can take a whole lot, I guess
07:45	TEttinger	I know modern browsers do this
07:45	crocket	It could be -Xms option.
07:46	crocket	-Xms 512M could cause this.
07:46	TEttinger	uh yes
07:46	TEttinger	that would make it always start with 512 MB used, do you want to know if it's used by lein?
07:47	crocket	The command lines don't specify -Xms or -Xmx.
07:47	crocket	I don't like this.
07:47	crocket	Python wouldn't consume this much.
07:49	crocket	hexchat consumes 23.5MB of RAM.
07:49	crocket	Does anyone plan to port clojure to python 3?
07:49	crocket	It wouldn't make sense for performance reasons, though.
07:49	TEttinger	huh, interesting. https://github.com/technomancy/leiningen/blob/master/bin/lein#L156-L158
07:49	TEttinger	crocket:
07:50	TEttinger	$google pixie lang
07:50	lazybot	[pixie-lang/pixie · GitHub] https://github.com/pixie-lang/pixie
07:50	TEttinger	it's very close to clojure, implemented in RPython (what PyPy uses) but not meant to call Python code yet
07:50	TEttinger	startup is one of its reasons to exist
07:50	kwladyka	crocket, i found solution like that about memory "You can set :jvm-opts in the user profile if you're using Leiningen 2. Otherwise set JVM_OPTS as an environment variable." Did you try that?
07:51	crocket	kwladyka, no
07:51	crocket	I didn't know about it.
07:51	TEttinger	yeah, I'd check if something else set your JVM_OPTS env var
07:52	crocket	I use leiningen 2.5.1 on openjdk 1.8.0_45.
07:52	crocket	Nothing sets JVM_OPTS in the user shell.
07:52	TEttinger	hm
07:52	TEttinger	JAVA_OPTS can also do it
07:53	TEttinger	(older java used that, lein treats it as an alias)
07:53	kwladyka	https://groups.google.com/forum/#!topic/clojure/h3M-LSlE4dw Larry Travis answer - maybe it is solution for you
07:53	crocket	I expect pixie to be different from clojure.
07:53	TEttinger	yes, no libs for one :)
07:53	crocket	No clojar
07:54	TEttinger	but it's very very close in terms of language features. it's also at an early state, (they were doing a major refactor last I checked a few months ago, to try to change how lazy seqs worked or something)
07:57	crocket	Ok, I specified :jvm-opts in ~/.lein/profiles.clj
07:57	crocket	Why did they name it pixie?
07:57	crocket	If they wanted it to be a clojure implementation on python, they would have named it accordingly.
07:58	TEttinger	I'm working on a clojure-like lisp as well, but using Perl 6's toolchain instead of PyPy. I'm encountering a rare problem in that the tools I am using to implement a new language, already have way more features than my language is going to even plan to have
07:58	TEttinger	it isn't directly clojure, and they planned to diverge in new features
07:58	TEttinger	(they have transducers in from the start, for example)
07:59	TEttinger	^ last 2 lines re: pixie
07:59	crocket	I expect clojure to be faster than the perl reincarnation and pixie.
07:59	crocket	python VM is not fast enough.
07:59	TEttinger	yes. except for startup and memory usage
08:00	crocket	pixie would suit command line programs and GUI programs.
08:00	crocket	Because of startup time and memory usage.
08:00	TEttinger	java and the JVM have atrocious startup time compared to scripting language VMs. thankfully, the perl thing I'm using can produce JVM bytecode or a scripty VM's bytecode (MoarVM)
08:01	crocket	Will anyone fix clojure's slow startup time?
08:01	TEttinger	there are some ways you can mitigate it
08:01	crocket	JVM itself is not slow to launch.
08:01	TEttinger	starting with the --server JVM will always slow down launch relative to --client
08:02	TEttinger	but --server does way more opts as your program runs
08:02	crocket	I heard http://clojure-android.info/skummet/ aims to reduce startup time.
08:02	TEttinger	there's a mix in JDK 7 and newer, you can pass the args... let me find em
08:02	crocket	skummet
08:04	TEttinger	-server -XX:+TieredCompilation
08:04	TEttinger	the second arg is only available for server JVMs, and it gives it -client JVM like startup behavior
08:04	TEttinger	it SHOULD be the default on -server
08:05	crocket	It seems leiningen ignores ~/.lein/profiles.clj outside leiningen projects.
08:05	TEttinger	low-end machines, particularly 32-bit windows machines, don't always have -server available as an option
08:06	crocket	It seems lein repl is beyond hope.
08:07	crocket	It is greedy of RAM.
08:08	TEttinger	were you passing an -Xmx option?
08:08	crocket	yes
08:08	crocket	-Xmx512m
08:08	crocket	And, it uses 350MB.
08:09	TEttinger	well that's not disobeying the -Xmx, but it is still a fair amount...
08:09	crocket	Why does leiningen ignore ~/.lein/profiles.clj outside leiningen projects?
08:10	TEttinger	I don't know if it does, actually -- I think the profile may affect your project when it runs, not the lein program itself
08:10	TEttinger	but I have no idea
08:11	crocket	I mean lein repl
08:11	crocket	Why does 'lein repl' ignore ~/.lein/profiles.clj outside leiningen projects?
08:15	TEttinger	oh!
08:15	TEttinger	The :base profile provides dependencies necessary for basic repl functionality, adds dev-resources to the :resources-path, and sets defaults for :jvm-opts, :checkout-deps-share and :test-selectors. It is part of Leiningen itself; you shouldn't need to change it.
08:17	crocket	TEttinger, What is the clojure-like language that targets perl 6?
08:17	crocket	Does it compile to perl 6?
08:18	TEttinger	uhhh I'm making it and I don't know perl 6, don't expect much yet :)
08:18	TEttinger	https://github.com/technomancy/leiningen/blob/9c5192e6520fb96aa625313a468e0143001f54ca/leiningen-core/src/leiningen/core/project.clj#L467-L470
08:18	TEttinger	that link is the default set of JVM opts that :base adds
08:18	crocket	It seems Rakudo Perl targets MoarVM and JVM.
08:18	TEttinger	yes
08:18	TEttinger	that's what I will too
08:18	crocket	Whut
08:19	crocket	TEttinger, How are you desining your clojure-like language?
08:19	crocket	What does it target?
08:19	TEttinger	I'm writing it with NQP, which is Not Quite Perl, a subset of Perl 6 meant for making compilers
08:19	TEttinger	(perl 6 is really really big in terms of feature scope)
08:20	TEttinger	(NQP is a smaller subset that they can bootstrap)
08:21	TEttinger	anything that uses NQP to make a compiler outputs a "QAST", which is effectively the same as a clojure ast in my case after it's been fully macroexpanded (no compile time logic)
08:21	TEttinger	JVM and Moar backends take a QAST and compile it to a native jar or exe, respectively, I think
08:21	crocket	Is there any clojure implementation suitable for command line programs?
08:21	crocket	or any lisp
08:22	TEttinger	I'd say pixie is about as close to clojure and command line as you'd get
08:22	crocket	pixie dust
08:22	TEttinger	other things get more scheme-like or common lisp like
08:23	TEttinger	SBCL has worse compile times than clojure, from what I hear, but produces very good optimizations
08:23	TEttinger	(not sure about repl in there)
08:23	crocket	"Pixie implements its own virtual machine. It does not run on the JVM, CLR or Python VM."
08:23	TEttinger	yep
08:23	crocket	And, it's written in python.
08:23	TEttinger	PyPy's RPython is a toolchain for making VMs
08:24	TEttinger	well, the bootstrapper is in RPython and even that isn't all of Python
08:24	crocket	Is scheme decent for command line programs?
08:24	wasamasa	yes
08:24	crocket	What about common lisp?
08:24	TEttinger	there are many schemes though
08:24	wasamasa	common lisp sucks for that purpose
08:24	wasamasa	not a single open-source implementation has tree shaking
08:25	TEttinger	racket is a good bridge between Clojure features and Scheme-ness
08:25	wasamasa	and therefore cannot produce binaries comparable with what you'll otherwise find there
08:25	crocket	???
08:25	lazybot	crocket: Yes, 100% for sure.
08:25	TEttinger	there's actually a racket lib that adds clojure data structures, immutable and all, to racket
08:25	crocket	I don't know tree shaking.
08:25	TEttinger	Racket is a scheme
08:25	crocket	Is Racket a functional programming language?
08:25	wasamasa	nope
08:25	TEttinger	?
08:26	crocket	Is there a functional lisp dialect suitable for command line?
08:26	TEttinger	racket has immutable and mutable data structures like clojure
08:26	wasamasa	it's a good deal closer than CL though
08:26	wasamasa	crocket: stop treating "functional" as a binary value
08:27	wasamasa	crocket: makes about as much sense as doing the same for OO
08:28	crocket	javascript sucks.
08:28	TEttinger	racket doesn't support the same type of concurrency stuff as clojure. I don't think any other lisps do as well as clojure in that arena
08:28	crocket	pixie is close?
08:28	crocket	pixie has STM and CSP.
08:28	TEttinger	do you mean CPS?
08:29	wasamasa	crocket: I also suggest you to just start writing code instead of spending all day asking #clojure about theoretical things
08:29	TEttinger	I like talking though!
08:29	TEttinger	it means my brain hurts less from perl stuff!
08:29	expez	I deployed a version that I don't want to promote to a proper release to clojars, when I try to deploy agai I get ReasonPhrase: Forbidden. What gives?
08:30	wasamasa	crocket: you may learn valuable things along the way such as that there is no perfect programming language
08:30	wasamasa	crocket: or that one programming language is better suited for a certain task than another
08:30	TEttinger	clojure is very very good for server apps
08:30	wasamasa	crocket: or that people writing code usually learn other languages as well
08:31	crocket	ClojureScript on node.js could be made decent on command line.
08:35	crocket	TEttinger, Do you have other recommendations for command line than pixie?
08:35	crocket	pixie doesn't even have a tutorial yet.
08:37	TEttinger	try lots of lisps. racket has a heavy focus on being useful for whatever people want to adapt it for, since it's primary unique feature is the ability to make new language modes that are still valid racket (one has algol syntax)
08:37	TEttinger	racket also has a better documentation generator than, uh, everything
08:38	TEttinger	(it's a tool called Scribble and it really produces very good docs)
08:38	crocket	Whut
08:39	crocket	Does clojure target python vm?
08:39	TEttinger	not that I know of, it potentially could
08:39	TEttinger	better would be LLVM, like many other languages are starting to try
08:41	crocket	https://github.com/halgari/clojure-py/ not useable
08:41	crocket	only 7 commits
08:41	TEttinger	as far as I can tell, LLVM has a number of advantages that explain why Apple is investing so heavily in it, and one is the quality of debugging and compilation speed that they get with Clang, the C/C++ compiler targeting LLVM, relative to GCC
08:41	crocket	LLVM sounds complex.
08:41	TEttinger	it is. it does have a lot of stuff under its banner
08:42	wasamasa	crocket: will you promise me to go quiet if I hand you a lispy language with a tutorial that's capable of producing executables and starting up quickly?
08:42	TEttinger	hehe
08:43	wasamasa	not to mention an alive community and sufficient amount of libraries
08:44	crocket	That sounds magical
08:44	wasamasa	it's not if you relax your criteria a bit
08:44	wasamasa	http://call-cc.org/
08:44	crocket	Actually, I was overwhelmed by lisp dialects....
08:44	crocket	Racket, chicken scheme, et al...
08:44	wasamasa	I'm using it for writing my CLI utilities and some simplistic web applications
08:45	crocket	I surmise chicken scheme is a decent language.
08:45	wasamasa	it's no clojure, but eh, I'm fine with scheme
08:47	crocket	I'd be happier if there is a clojure implementation that starts up fast because that means one less language to learn.
08:47	wasamasa	lol
08:48	crocket	I could probably try ClojureScript on node.js
08:48	wasamasa	just give up on it, as a good developer learning languages is a necessity
08:48	wasamasa	well, clojurescript's tooling sucks
08:48	crocket	Does it have leiningen?
08:48	wasamasa	you'll have to start with a clojure project first, then add clojurescript as dependency
08:48	wasamasa	then write some lines to make leiningen compile javascript
08:49	crocket	wasamasa, It seems chicken scheme implements R5RS. Does R6RS improve on R5RS in any aspect?
08:49	wasamasa	crocket: R6RS is very different from R5RS
08:50	wasamasa	crocket: R7RS is an attempt to actually improve R5RS and splitting the language into a small and large version
08:50	wasamasa	crocket: and chicken supports a good amount of the small version of R7RS
08:52	crocket	It seems committee has dominated scheme.
08:53	crocket	I have a selection disorder.
08:57	crocket	wasamasa, Does chicken scheme compile to native binaries directly?
08:57	kwladyka	wasamasa, did you use lein-sub?
08:57	wasamasa	kwladyka: nope
08:57	Bahman	wasamasa: Count me in :-D
08:58	wasamasa	Bahman: and I thought I was just seeing things
08:58	kwladyka	wasamasa, ok. I am just looking somebody who can explain me https://github.com/ring-clojure/ring architecture :)
08:59	wasamasa	kwladyka: not sure how a leiningen plugin comes into play there
08:59	Bahman	crocket: One of the strengths of Chicken (and Racket) are native binaries.
08:59	wasamasa	Bahman: didn't racket switch to having a VM?
08:59	Bahman	wasamasa: Yes...but the binary contains the slimmed down VM for easy redistribution.
08:59	Bahman	Pretty neat.
09:00	kwladyka	wasamasa, do you have any idea why author of code choose to have all this projects inside one repository then separate them?
09:00	wasamasa	well, ok
09:00	wasamasa	kwladyka: I suggest asking them
09:00	kwladyka	;)
09:01	kwladyka	it can be a solution :)
09:01	kwladyka	and maybe the esiest in this case
10:02	crocket	Is it ok to write a GUI program in clojure with a JavaFX binding?
11:19	whodidthis	https://www.refheap.com/104291 any way i could make core.match work in tests? 😿
11:25	crocket	Will clojure be fixed with regard to nil?
11:26	mmeix	What should be fixed?
11:26	crocket	nil
11:26	crocket	Nil causes errors
11:27	mmeix	example?
11:27	mmeix	,(doc fnil)
11:27	crocket	(if ({:a nil :b 1} :a) "ok" "no")
11:27	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."
11:27	crocket	,(if ({:a nil :b 1} :a) "ok" "no")
11:27	clojurebot	"no"
11:28	crocket	It leads to logical bugs.
11:28	crocket	,(if (contains? {:a nil :b 1} :a) "ok" "no")
11:28	clojurebot	"ok"
11:29	crocket	Since nil is everywhere, it is difficult to find the origin of nil.
11:29	whodidthis	maybe core.typed will help you out
11:30	crocket	nil should have been an interop feature.
11:31	mmeix	,(if ({:a nil :b 1} :a) "ok" "no")
11:31	clojurebot	"no"
11:31	mmeix	is perfectly ok, because nil is falsey
11:32	mmeix	"Both nil and false are treated as "false" and everything else is treated as true."
11:32	mmeix	http://blog.jayfields.com/2011/02/clojure-truthy-and-falsey.html
11:32	crocket	Somehow, it leads to bugs.
11:32	crocket	nil leaks into collections.
11:32	crocket	conditionals return false because nil leaked into collections somehow in a large codebase.
11:33	mmeix	I guess, nil will not declared truey ...
11:34	Bronsa	crocket: no, it will never be "fixed". it's not considered a bug or misfeature
11:34	mmeix	maybe this helps:
11:34	mmeix	http://blog.jayfields.com/2011/01/clojure-fnil.html
11:34	crocket	nil shouldn't have been part of the core in the first place.
11:34	Bronsa	that's your opinion
11:34	crocket	Rich Hickey was forced to use nil due to JVM.
11:35	Bronsa	do you have any evidence to back that claim or is it just you assuming things?
11:35	crocket	Nil is a mistake in programming languages.
11:35	crocket	Nil, Null, ...
11:35	Bronsa	cool. you seem to have made up your mind. have fun trying to convince the core team I guess
11:36	crocket	mmeix, I think fnil is a band aid at best.
11:37	mmeix	hm ...
11:38	mmeix	I'm a beginner, but the concept of only nil and false being falsey seemed very plausible to me
11:38	mmeix	instead of say 0 being false, for example
11:38	mmeix	etc.
11:38	crocket	mmeix, My point is that I feel much better without nil in the core.
11:39	crocket	Nil is better served as a java interop feature.
11:39	mmeix	this is not going to happen, it would break nearly everything
11:39	crocket	I know
11:39	mmeix	AFAIK
11:40	mmeix	what is wrong with your example (if ({:a nil :b 1} :a) "ok" "no")?
11:40	mmeix	don't see the point
11:40	crocket	If a programmer assumes a map doesn't have nil, it is a problem.
11:42	mmeix	Something other: trying "boot" for he first time, and doing some silly error somewhere - could someone have a quick look at: https://www.refheap.com/104324
11:44	mmeix	,(contains? {:a nil :b 1} :a)
11:44	clojurebot	true
11:44	mmeix	if that matters
11:47	mmeix	what should (first {}) return? false?
11:47	mmeix	,(first {})
11:47	clojurebot	nil
11:59	crocket	Why does clojure not have an option type?
12:23	hellofunk	is the idea behind an option type to simply differentiate between "no value is there" vs "a value is there, but the value is nothing" ?
12:30	noidi	crocket, http://clojure.github.io/core.typed/#clojure.core.typed/Option
12:32	crocket	Thanks
12:32	mmeix	ad hoc: is core.typed preferable to prismatic/schema ?
12:32	crocket	I have my eyes on pixie which is similar to clojure and loads fast.
12:33	crocket	pixie would be great for embedded devices and command line programs.
12:34	whodidthis	maybe you can start a core.typed for pixie
12:34	justin_smith	mmeix: schema is about runtime assertions, typed is about proving things at compile time
12:35	mmeix	ah, ok ... thanks
12:39	clojer	I'm finding the more I work with Clojure the more I don't want to work with anything else. Can't decide whether that's a good or a bad thing :)
12:42	clojer	S-expressions just make it so easy to extract parts of a function and test in the repl by throwing some values at them.
12:48	hellofunk	clojer: welcome to lisp!
12:49	wasamasa	they want to know from me what I've learned at work
12:49	wasamasa	and it's been mostly clojure and clojurescript
12:50	Jickelsen	Asked this before but it was probably at a bad time of day :) I've included react-with-addons (from CDN) but (aget js/React "addons") returns nil. Any ideas?
13:12	kwladyka	What are you using to database migrations?
13:15	sdegutis	Are there any decent OCR libraries for Clojure?
13:25	clojer	Why does seq destructuring of a map change the original? For example:
13:25	clojer	(let [m { 365 [{:a 1 :b 2} {:a 4 :b 6}] 366 [{:a 11 :b 22} {:a 44 :b 66}]}] (for [[id [mps] :as orig] m] orig))
13:25	clojer	Produces: ([365 [{:b 2, :a 1} {:b 6, :a 4}]] [366 [{:b 2, :a 1} {:b 6, :a 4}]])
13:26	clojer	The original map has not been retained as a map.
13:26	justin_smith	clojer: a hash-map is made of entry objects
13:26	TEttinger	because for isn't changing the original?
13:26	TEttinger	for returns a new seq
13:26	justin_smith	for cannot return a hash-map
13:27	justin_smith	you can make a hash-map out of the entries there though
13:27	TEttinger	,(let [m { 365 [{:a 1 :b 2} {:a 4 :b 6}] 366 [{:a 11 :b 22} {:a 44 :b 66}]}] (into {} (for [[id [mps] :as orig] m] orig)))
13:27	clojurebot	{365 [{:a 1, :b 2} {:a 4, :b 6}], 366 [{:a 11, :b 22} {:a 44, :b 66}]}
13:28	clojer	I naively thought :as orig did exactly that, ie. saved the original, not transformed it.
13:29	whodidthis	orig there is a single key value pair
13:30	justin_smith	clojer: :as is a convenience for capturing bindings, but there is no binding in for that will capture the entirety of the original collection
15:11	whodidthis	how do i make a string from a list of strings in emacs lisp
15:11	Bronsa	whodidthis: what does this have to do with clojure?
15:13	whodidthis	ok, whats kind of like (apply str '("abc" "def")) but in emacs lisp
15:14	TimMc	haha
15:14	whodidthis	most of us not originated from the great land of lisp :(
15:15	whodidthis	s/most/some
15:18	wasamasa	(mapconcat #'identity '("foo" "bar") "")
15:18	wasamasa	next time, ask on #emacs
15:20	wasamasa	you can alternatively do it like you'd do in any other lisp, but I bet there's some stupid reason for not doing so, like it's version of apply and funcall being braindead
15:20	wasamasa	yup: "If a subr takes more than 8 arguments without using MANY or UNEVALLED, we need to extend this function to support it. Until this is done, there is no way to call the function."
15:27	TimMc	...emacs lisp can't apply when the fn doesn't specifically support it?
15:31	wasamasa	that's in the sources of funcall
15:31	wasamasa	so, I dunno how to interpret this, maybe it's a limitation at the C level
15:32	wasamasa	experimentation at elisp level doesn't suggest there's anything wrong
15:36	whodidthis	apparently there was a new function called string-join, i was a bit dum for trying to find something apply-like in elisp
15:42	wasamasa	it's using the same thing I suggested
15:42	wasamasa	and is relatively recent
16:34	kwladyka	Is any common rules for returning errors in Clojure from functions? For example validation error like "email is to valid".
16:46	kwladyka	Why you will choose Pedestal instead of Ring?
16:48	tcrayford____	kwladyka: for the former question: typically I'd use a value like a map or something in that case, exceptions in others
16:49	kwladyka	tcrayford____, yes.... i can't get used to i don't need some class for that...
16:50	kwladyka	Do you have any experience Validateur vs Bouncer?
16:50	tcrayford____	nope. I use mississippi and it's worked fine for me
18:01	zakwilson	I'm looking for an IMAP client library. All I've found so far is clojure-mail, a very gmail-specific wrapper around JavaMail. Is there something more general I should look at, or should I just use a Java library?
18:03	bbloom	zakwilson: in general, you should prefer java libraries over clojure wrappers of java libraries.... unless the clojure wrapper is particularly good
18:03	bbloom	clojure is designed to make it easy to call jvm code w/o a wrapper. so the wrapper needs to provide some substantial benefit to justify itself
18:05	bbloom	and "saves you from typing a dot character" is not substantial benefit
18:07	zakwilson	No, but converting from Java's representation of an email message to a Clojure map and dealing with what look to be a few thorny issues with JavaMail like clojure-mail does might be.
18:12	bbloom	zakwilson: a quick look at the library suggests to me it's probably not worth wrapping
18:13	bbloom	or at least not worth wrapping in a general way: write the adaptor functions you need, reference clojure-mail if you need to for how to do some things
18:13	bbloom	cut out all the stuff you don't need/want
18:14	bbloom	or fork it and make the changes you need to be less gmail-specific
18:16	zakwilson	bbloom: I was leaning toward forking it, as that doesn't look terribly hard. I was hoping for there to be a Right Thing I could use though, and it doesn't look like there is.
18:18	bbloom	zakwilson: i was telling you what (many in) the community will tell you is "the right thing": just call the jvm libs & write functions to make it nicer as you need them
18:18	bbloom	the extra indirection only adds bulk and complexity
18:21	jonathanj	is there a better way of expressing: (into {} (for [[k v]] (some-func {:x k} v))) ?
18:23	bbloom	jonathanj: not sure what you're trying to express, since your `for is malformed
18:23	jonathanj	it is?
18:24	bbloom	,(for [[k v]] anything)
18:24	clojurebot	#error {\n :cause "for requires an even number of forms in binding vector in sandbox:"\n :via\n [{:type clojure.lang.Compiler$CompilerException\n :message "java.lang.IllegalArgumentException: for requires an even number of forms in binding vector in sandbox:, compiling:(NO_SOURCE_FILE:0:0)"\n :at [clojure.lang.Compiler macroexpand1 "Compiler.java" 6644]}\n {:type java.lang.IllegalArgumentExce...
18:25	jonathanj	(for [[k v] some-map] ...) then
18:25	bbloom	jonathanj: you need an expression for [k v] to iterate over
18:25	bbloom	so you're trying to apply a function to each key in a map and then get a new map with the same values?
18:26	jonathanj	uh, i don't think that's what that code does
18:26	jonathanj	i want to apply a function to each value in a map, with access to the key, and have it result in a new map
18:27	bbloom	(reduce (fn [m [k v]] (assoc m k (f k v))) {} m)
18:29	bbloom	or just (into {} (map f m))
18:34	jonathanj	bbloom: yeah, i guess into map makes more sense than into for, thank you
18:36	whomp	how can i get a list of all the values of a hashmap? like the keys fn, but for values instead
18:37	whomp	oh... vals... seems reasonable
19:17	jonathanj	is there a less repetitive way of writing: (cond (map? value) ... (vector? value) ...)?
19:18	bbloom	jonathanj: what repetition are you attempting to eliminate?
19:18	justin_smith	jonathanj: for one thing, a multimethod can replace a cond over types
19:19	jonathanj	bbloom: repeating `value`
19:20	jonathanj	justin_smith: true, but it's quite a small task
19:22	bbloom	jonathanj: you can 1) just deal w/ it, as it's not the problematic kind of repetition (spreading knowledge to multiple places) or 2) choose a smaller variable name or 3) probably can use condp
19:22	bbloom	(doc condp)
19:22	clojurebot	"([pred expr & clauses]); Takes a binary predicate, an expression, and a set of clauses. Each clause can take the form of either: test-expr result-expr test-expr :>> result-fn Note :>> is an ordinary keyword. For each clause, (pred test-expr expr) is evaluated. If it returns logical true, the clause is a match. If a binary clause matches, the result-expr is returned, if a ternary clause matches, its result-fn, which must be a unary fu
19:23	bacon1989	bbloom: it was something I was going to suggest, but I think that would just lengthen his code
19:23	bacon1989	IPersistentMap doesn't seem shorter to me ;)
19:26	bbloom	,(let [value "foo"] (condp (fn [f _] (f value)) nil keyword? 1 symbol? 2 string? 3 number? 4))
19:26	clojurebot	3
19:27	bbloom	you can write a macro for that, or a custom macro built on cond
19:27	bbloom	or, really, just don't worry about that superficial repetition
19:29	bbloom	,(defmacro condv [v & clauses] `(let [v# ~v] (condp (fn [f# _#] (f# v#)) nil ~@clauses)))
19:29	clojurebot	#'sandbox/condv
19:29	bbloom	,(condv "foo" keyword? 1 symbol? 2 string? 3 number? 4)
19:29	clojurebot	3
19:29	bbloom	,(condv 567 keyword? 1 symbol? 2 string? 3 number? 4)
19:29	clojurebot	4
19:29	bbloom	,(condv 'there-you-go keyword? 1 symbol? 2 string? 3 number? 4)
19:29	clojurebot	2
19:30	jonathanj	,(condp #(%1 %2) {} map? :map :else :unknown)
19:30	clojurebot	:map
19:30	bbloom	er duh, yeah, that works better than mine closing over value
19:30	bbloom	go with that
19:30	jonathanj	is there another way of writing #(%1 %2)?
19:31	bbloom	no
19:31	amalloy	infinitely many ways, but none of them very good
19:31	bbloom	yeah that
19:32	bbloom	,(defn call [f & args] (apply f args))
19:32	clojurebot	#'sandbox/call
19:32	bbloom	,(condp call {} map? :map :else :unknown)
19:32	clojurebot	:map
19:33	jonathanj	(comp eval list) is what i came up with
19:33	jonathanj	but okay, i'll just use the macro
19:33	justin_smith	eval for that is like using a chainsaw to do your nails
19:35	amalloy	(inc justin_smith)
19:35	amalloy	lazybot pls
19:35	clojurebot	Cool story bro.
19:35	jonathanj	i generally assume that using anything like "eval" or "exec" in any language is like that :P
20:05	bacon1989	will there every come a day where clojure is written entirely in C, and has an FFI that works with C libraries fairly well
20:06	bacon1989	not that i'm asking for it, I think it would be cool
20:06	bacon1989	I would just love to see commandline tools written in clojure
20:07	bacon1989	skummet definitely helps, but it's a crutch to the main problem
20:07	bbloom	bacon1989: https://github.com/pixie-lang/pixie
20:08	bacon1989	oh yeah, I think that's awesome
20:09	bacon1989	but that's in 'pre-alpha'
20:09	bacon1989	in time though
20:11	bacon1989	i'm liking the direction of pixie actually
20:11	bacon1989	maybe I just need to be patient
20:12	bacon1989	'clojure inspired lisp'
22:19	jjttjj1	is there a way built into incanter to get a dataset from a sequence of maps keyed by the colnames?
22:21	jjttjj1	found it, to-dataset works
23:18	keramida	ma