#clojure – 2017-02-22

2017-02-22

11:06	Ardx	what does the @ symbol mean in macros?
11:11	wink	that feeling when you read such a question and first have to check what language channel you're in. :P
11:11	mavbozo	@ is a shorthand for deref function
11:12	Ardx	how is it different from ~
11:12	Ardx	?
11:12	mavbozo	is the @ symbol you see has ~ in front of it?
11:12	mavbozo	like ~@
11:12	Ardx	well I'm trying to use it
11:13	Ardx	~@ seems to make it worse :D
11:13	clojurebot	Gabh mo leithscéal?
11:13	mavbozo	~please listen clojurebot
11:13	clojurebot	Excuse me?
11:14	mavbozo	,(def three-and-four (list 3 4))
11:14	clojurebot	#error {\n :cause "SANBOX DENIED"\n :via\n [{:type java.lang.Exception\n :message "SANBOX DENIED"\n :at [clojure.core$eval3$fn__4$fn__17 invoke "NO_SOURCE_FILE" -1]}]\n :trace\n [[clojure.core$eval3$fn__4$fn__17 invoke "NO_SOURCE_FILE" -1]\n [clojure.core$eval3$fn__4 invoke "NO_SOURCE_FILE" 0]\n [clojure.core$eval3 invokeStatic "NO_SOURCE_FILE" 0]\n [clojure.core$eval3 invoke "NO_SOURCE_FIL...
11:14	mavbozo	,(def a 1)
11:14	clojurebot	#error {\n :cause "SANBOX DENIED"\n :via\n [{:type java.lang.Exception\n :message "SANBOX DENIED"\n :at [clojure.core$eval29$fn__30$fn__43 invoke "NO_SOURCE_FILE" -1]}]\n :trace\n [[clojure.core$eval29$fn__30$fn__43 invoke "NO_SOURCE_FILE" -1]\n [clojure.core$eval29$fn__30 invoke "NO_SOURCE_FILE" 0]\n [clojure.core$eval29 invokeStatic "NO_SOURCE_FILE" 0]\n [clojure.core$eval29 invoke "NO_SO...
11:14	mavbozo	~aaargh
11:14	clojurebot	Gabh mo leithscéal?
11:16	Ardx	mavbozo this is my code http://pastebin.com/tUKyrd8a
11:16	Ardx	see it produces nil a lot
11:16	mavbozo	,(let [tf (list 3 4)] `(1 ~@tf))
11:16	clojurebot	(1 3 4)
11:17	mavbozo	the ~@ unquote-splicing removes the parentheses from a list
11:17	mavbozo	,(let [tf (list 3 4)] `(1 ~tf))
11:17	clojurebot	(1 (3 4))
11:18	Ardx	ah ok dont think that helps then
11:25	Ardx	Hmm are macros expanded before defs are initialised?
11:25	Ardx	that would explain why I get nil, as what I pass in is empty
11:38	Ardx	,(= 2 3)
11:38	clojurebot	false
11:38	Ardx	hmm how do I actually set values in clojure
11:46	mavbozo	Ardx, in a namespace you can bind value to a var using def
11:46	mavbozo	,(def x 1)
11:46	clojurebot	#error {\n :cause "SANBOX DENIED"\n :via\n [{:type java.lang.Exception\n :message "SANBOX DENIED"\n :at [clojure.core$eval31$fn__32$fn__45 invoke "NO_SOURCE_FILE" -1]}]\n :trace\n [[clojure.core$eval31$fn__32$fn__45 invoke "NO_SOURCE_FILE" -1]\n [clojure.core$eval31$fn__32 invoke "NO_SOURCE_FILE" 0]\n [clojure.core$eval31 invokeStatic "NO_SOURCE_FILE" 0]\n [clojure.core$eval31 invoke "NO_SO...
11:46	mavbozo	~darn
11:46	clojurebot	No entiendo
11:47	Ardx	Yeah I may as well figure out the clojure fnctional way of doing it though
11:48	scriptor	Ardx: you use (let) for local bindings, but try to think in terms of transformations and flows of data
11:48	scriptor	rather than setting values at each step
12:05	osfabibisi	Ardx: do you need a macro?
12:06	osfabibisi	if you are both trying to single-step through because it's complicated and asking about the syntax, then you may be biting off more than you can chew? ;-P
12:06	osfabibisi	(I feel I can say this, because I was doing exactly the same thing a month ago...)
12:15	Ardx	Yeah I started clojure yesterday
12:16	Ardx	But I fixed the macro now
12:17	Ardx	Now I'm just wondering, if I have a tree structure of hashmap, and I update a leaf node, how do I then add that lea node back onto the tee?
12:18	Ardx	Because it's all immutable, I can't just update one value. I guess I have to go back up the chain and recrate every hashmap along the way
12:18	technomancy	you would use update-in
12:19	technomancy	,(update-in {:a {:b [45 88 {:c 5}]}} [:a :b 2 :c] inc)
12:20	clojurebot	{:a {:b [45 88 {:c 6}]}}
12:20	Ardx	hmmm
12:23	Ardx	that would update any :a :b :c it finds though
12:23	technomancy	no, the second arg is a linear path to follow
12:24	Ardx	ahh
12:24	technomancy	,(update-in {:a {:b [45 88 {:c 5}]}} [:b 2 :c] inc)
12:24	clojurebot	#error {\n :cause nil\n :via\n [{:type java.lang.NullPointerException\n :message nil\n :at [clojure.lang.Numbers ops "Numbers.java" 1013]}]\n :trace\n [[clojure.lang.Numbers ops "Numbers.java" 1013]\n [clojure.lang.Numbers inc "Numbers.java" 112]\n [clojure.core$inc invokeStatic "core.clj" 919]\n [clojure.core$inc invoke "core.clj" 914]\n [clojure.lang.AFn applyToHelper "AFn.java" 154]\n ...
12:24	osfabibisi	or you can use zippers
12:24	technomancy	osfabibisi: hush you; he's on his second day
12:24	osfabibisi	technomancy: then he shouldn't be playing with macros :D
12:24	technomancy	true
12:24	Ardx	\o/
12:25	justin_smith	macros are for absolute beginners (so you know what they hell they are about) and for people of advanced expertise who are redefining the language in their code, in between you'll rarely need macros
12:26	osfabibisi	justin_smith: ooo, good point ;-)
12:26	justin_smith	I'm barely at the point where making my own macros is a good idea myself
12:26	technomancy	day 2 of learning clojure: write three macros, understand how they work, and throw them immediately away
12:26	justin_smith	right
12:27	justin_smith	there's an optional "make a semi useful lib and fill it with domain specific macros with a cute syntax" - just skip that idea and throw it away
12:28	osfabibisi	;-)
12:29	osfabibisi	one day, there will be a `git diff` that isn't rendered crazy by the reordering of functions...
12:29	justin_smith	osfabibisi: it's possible to make diff plugins for git that are smarter about individual languages
12:30	osfabibisi	justin_smith: is there one for clojure that you can recommend?
12:30	justin_smith	it would be cool to make a diff plugin for clojure using planck (since it starts up fast and knows about clojure syntax...)
12:30	justin_smith	osfabibisi: not that I know of, but I think it would be an awesome idea
12:30	justin_smith	diffing by form/sexp rather than line...
12:30	osfabibisi	that said, diffing by sexp isn't my problem here
12:31	osfabibisi	it's 2 forms changing order e.g. (defn foo ......) (defn bar ......) getting swapped around
12:31	osfabibisi	which always results in one hunk being deleted from origin point and added to new point, because diff algos only work on things as sequences
12:32	justin_smith	osfabibisi: that's what I mean, if it was looking at balanced forms / subforms, it would know not to do weird splitting in the middle like that
12:32	justin_smith	it's diffing by line, which gives the weirdness
12:32	osfabibisi	no no, I've explained badly, sorry
12:33	osfabibisi	e.g. the definition of (defn foo ...) moves from line 15 to line 100
12:33	justin_smith	osfabibisi: I think we just disagree about why git is misbehaving
12:33	justin_smith	I know the behavior
12:33	osfabibisi	the forms are still balanced
12:33	amalloy	i think osfabibisi is complaining about even more benign behavior than you're thinking of
12:42	osfabibisi	yes, I think I understand what justin_smith is talking about - when 2 forms share common features
12:43	osfabibisi	but in this case they're not incorrectly misidentified, they've just moved
12:45	amalloy	there's not really a lot you can do about that in the unix diff model, since it's line based. there are sexp-based diff tools out there, though i don't know how good they are or whether you can get them involved in git diff at all
12:45	Ardx	so if I have a tree, made of hash maps, and then I have a list [:area :top], is there a function that does something like (get-leaf root-map [:area :top]), and iterates that list and goes down through the tree?
12:47	amalloy	actually i bet you could configure diff.tool to point to a shell script that launches your sexp differ for .clj files and a standard diff otherwise
12:47	Ardx	or I could use a macro to turn it into "(-> :area :top)" I guess
12:47	amalloy	(doc get-in)
12:47	clojurebot	"([m ks] [m ks not-found]); Returns the value in a nested associative structure, where ks is a sequence of keys. Returns nil if the key is not present, or the not-found value if supplied."
12:47	osfabibisi	probably. but again if it's sequence-based that won't really help for this case
12:47	osfabibisi	instead, I'm just going to give colleagues a hard time about their commit being impossible to review :D
12:47	Ardx	amalloy cheers!
13:04	justin_smith	amalloy: yeah- a sexp based diff for sexp languages was kind of what I had in mind
13:55	osfameron	what's the minimum I need to do to set a classpath in a boot repl?
13:55	osfameron	e.g. I have a project template I know works, if I have src/project/foo.repl and a namespace project.foo
13:56	osfameron	and a boot.build and so on
13:56	osfameron	but if I just want to edit scratch.clj to play around then my editor complains " Could not locate scratch/scratch__init.class or scratch/s
13:56	osfameron	cratch.clj on classpath"
14:05	justin_smith	osfameron: for super basic stuff I just use load-file
14:05	justin_smith	eg. $ vim /tmp/scratch.clj then (load-file "/tmp/scratch.clj")
14:05	justin_smith	I leave require and such for things that are defined parts of my project
14:06	justin_smith	(I did find the annoying fact that I can't do macros in planck this way - it only allows macros via classpath... but that's the only hiccup I've had for this workflow)
14:07	osfameron	justin_smith: you mean from the repl itself?
14:07	osfameron	ah yes, that works
14:08	osfameron	and then fireplace stops complaining
14:08	osfameron	ta
14:08	justin_smith	osfameron: yes, I call load-file from the repl - though most editors with clojure integration have a simple keypress that invokes load-file
14:09	osfameron	fireplace has the odd thing that it's supposed to be namespace aware, but it can't seem to resolve the location of a file it actually has open...
14:09	osfameron	it all works with a properly set up project of course
14:10	justin_smith	aha - I use fireplace but only in a very rudimentary way - I think I just assumed that rando .clj file would not play nicely so I should use blunt tools like load-file
14:10	justin_smith	but that was based on hunches, not expertise
14:11	osfameron	if you open a project with a proper boot (or I imagine leiningen) setup, then everything Just Works
14:11	justin_smith	yeah, all my work since I started using fireplace is in a library that doesn't have its own repl / process, so I have not been so lucky
14:12	osfameron	and you can't use clojure's builtin repl?
14:12	justin_smith	osfameron: I have an app, the app runs from two repls, this library is used by each of the repl based apps
14:12	justin_smith	point being that the code I am editing is not on the classpath of either repl - they are using the version that was put in cache by lein install
14:13	osfameron	ah. sounds complicated
14:13	justin_smith	and I refuse to muck with the whole symlink nonsense
14:13	justin_smith	osfameron: it would be super complicated if I tried to have convenient tooling, but all I need is a repl plus load-file and things work
14:14	osfameron	:D
14:14	justin_smith	eg. there are two different repls that both want the new version of foo.clj - doing this via the editor would be silly
14:16	justin_smith	since editor tooling that allows multiple repls wants to map a file to a single repl in my experience
14:22	Ardx	ended up using assoc-in
14:22	Ardx	and an atom for the tree root :D
14:23	Ardx	and turned the macro into a function, so I could actually step throguh and debug the many problems the code had
14:23	Ardx	god dang are clojure errors cryptic though
14:24	justin_smith	Ardx: a good design strategy is to use a function for all your logic, and if you need a custom syntax, make a minimal macro where the function is doing the real work
14:24	justin_smith	I think you've learned already how much easier that is to debug (also if you need to build more functionality, a function is a much easier starting point than a macro usually)
14:25	machinewar	do you think clojure.spec would be good solution for masking data? pretty much need to restore data from one db to another, but obfuscate some of the data (but it needs to still resemble valid data)
14:25	machinewar	so I'm thinking you could for example describe the shape of a postal code, a first name, last name, etc
14:25	machinewar	and use it at runtime to generate fake data
14:25	justin_smith	that doesn't sound like what spec is for at all...
14:25	justin_smith	I mean I guess it plugs into generators for testing purposes...
14:26	machinewar	yea that's what I'm thinking
14:26	Ardx	justin_smith yeah keeping macros small sounds like a good plan
14:27	justin_smith	Ardx: of course there's special cases like core.match and core.async which build whole languages (very useful languages!) that can't just be summed up with a bunch of functions, but those are very special
15:46	justin_smith	why would a ref have a name?
15:47	dysfun	did you call name on it?
15:47	osfameron	hmm, maybe I don't mean refs then? "stuff that you've def'd" ?
15:47	dysfun	vars!
15:47	justin_smith	vars?
15:47	osfameron	dysfun: yes!
15:47	clojurebot	vars are a linking construct
15:47	dysfun	vars are not refs
15:47	osfameron	right, so vars then.
15:47	osfameron	they have names don't they?
15:48	justin_smith	,(:name (meta #'+))
15:48	clojurebot	+
15:48	osfameron	that doesn't seem to work for things I've def'd or defn'd myself though
15:49	justin_smith	def and defn both attach :name
15:49	justin_smith	(as a metadata)
15:49	osfameron	ah, I missed the #' bit... what does that do?
15:50	justin_smith	accesses the var
15:50	justin_smith	+ points to the function pointed at by the var
15:50	osfameron	ah... instead of the value?
15:50	justin_smith	#'+ gets the var itself
15:50	osfameron	ok
15:50	amalloy	osfameron: imagine (def x 1)
15:50	amalloy	you want x to eval to 1, not to a var
15:50	justin_smith	,#'+
15:50	clojurebot	#'clojure.core/+
15:50	justin_smith	err
15:50	justin_smith	,'#'+
15:50	clojurebot	(var +)
15:50	amalloy	but sometimes, you want to get at the var anyway, and that's what #'x does
15:50	osfameron	ok
15:51	justin_smith	#' is a reader macro, shorthand for (var )
15:51	amalloy	the name can't be stored on the value 1, and is instead stored on the var
15:51	osfameron	so why doesn't (name #'+) work?
15:51	justin_smith	well that's a more controversial decision
15:51	amalloy	so, name is for getting the "name" part of a name+namespace pair thingy
15:51	justin_smith	but regardless of reasons, at least the :name key on the metadata will help
15:51	osfameron	true
15:51	osfameron	thanks!
15:51	amalloy	and a var is not one of those; it is a lot more things than just a name
15:52	osfameron	ah
15:52	dysfun	a var has a named thing, but it isn't one
15:52	amalloy	,(keys (meta #'inc))
15:52	clojurebot	(:arglists :doc :inline :added :line ...)
15:53	osfameron	well, that was all so exciting, I've now forgotten why I thought I wanted to call (name) on a var in the first place...
15:56	justin_smith	osfameron: my assumptions is shenanigans of some sort
15:56	justin_smith	osfameron: consider that given a symbol, you can get a var and a name from it
15:56	justin_smith	,((juxt name resolve) '+)
15:56	clojurebot	["+" #'clojure.core/+]
15:56	justin_smith	maybe that's what you wanted? resolve is good for shenanigans
15:56	amalloy	a symbol and a namespace
15:57	justin_smith	amalloy: well, symbols can be namespaced, and resolve will use your namespace's lookup rules to find a namespace
15:57	amalloy	yes, "your namespace" is the namespace here that you need
15:58	amalloy	calling resolve at runtime outside of a repl without specifying a namespace is going to give you trouble
15:58	justin_smith	right, because your thing likely isn't available by any shorthand in user
15:58	osfameron	justin_smith: ooo, thanks
15:59	amalloy	(because ns is bound to the current namespace while in a repl, but it's not when running an actual program via -main)
15:59	justin_smith	amalloy: in my experience it's always bound to user, unless someone made some effort to switch it
15:59	justin_smith	I've never seen it unbound
16:00	amalloy	what i mean is, it's not bound to any useful value that you might think of as "the current namespace"
16:00	justin_smith	fair
16:01	technomancy	doesn't resolve DTRT when passed a qualified symbol?
16:01	osfameron	if I want to go the other way - e.g. I have a map of {name function, ...} what's the best way to get those defn'd together?
16:01	justin_smith	technomancy: if it's fully qualified, yes
16:01	technomancy	oh justin said that already
16:01	justin_smith	osfameron: intern
16:02	justin_smith	osfameron: the tricky part is that intern doesn't add the nice metadata that def/defn do
16:02	justin_smith	in my experience intern is a good sign you are being too clever for your own good (moreso than resolve is even)
16:03	osfameron	yes, probably
16:03	osfameron	it's quite a common ask in e.g. Perl though
16:03	justin_smith	osfameron: consider that looking something up in a hashmap and calling it is perfectly acceptable
16:03	osfameron	where you can define exporters custom exporters for functions
16:03	justin_smith	sure, and perl is known for tricky business as a common programming style, right?
16:04	justin_smith	I'm not saying intern is never valid, just that it indicates you are likely adding complexity, which is a good moment to ask what you are getting in return for that cost
16:04	osfameron	well, that's part of doing hard work behind the scenes to get a nice API for the user of a library
16:04	osfameron	but yes, point taken, and I'll see if I can avoid it :D
16:05	justin_smith	osfameron: but clojure is a very introspective and reflective language, and libraries that make it hard to find definitions or map definitions back to some form are really annoying
16:05	osfameron	is that a problem if I set the metadata politely?
16:05	justin_smith	we have a lot of tools to find the code that generated a thing, but tricks like intern undermine them
16:06	justin_smith	osfameron: hmm, I wonder how hard it would be to set the right file/line metadata automatically...
16:07	osfameron	so the thing I'm thinking about is a logging library
16:08	osfameron	(info "hello") might write to stdout or it might send a message to a queue or whatever
16:08	osfameron	and I want to avoid a singleton global
16:08	osfameron	(info my-logger "hello") is ok, and doesn't need any cleverness
16:09	justin_smith	aside - (but don't most clients of logging libraries expect a global behavior?)
16:11	osfameron	hmm, maybe?
16:11	osfameron	I think dysfun mentioned that being something he didn't like about timbre
16:12	osfameron	and it chimed with whatever I was thinking
16:12	osfameron	anyway, you could always (info global-logger "hello") if you wanted it :D
16:12	justin_smith	I don't fully agree, but I've seen it argued that logging config should be global and static and hard to modify dynamically because security
16:13	osfameron	static sure, but why does global help there?
16:14	osfameron	I kinda understand why people want the dynamic behaviour, but I've found that confusing far more often than actually useful
16:16	justin_smith	I guess less complexity means less possibility for corner cases or unexpected combinations of behaviors
16:16	justin_smith	it wasn't my argument so I'm not sure :)
16:17	justin_smith	I mean, once someone can change a var in my clojure program, that machine is hosed, messing with logging is the least of it
16:20	jonathanj	Where do you get the logger from that you want to log to?
16:23	jonathanj	Is it okay if your library uses a different logger than the user calling your library?
16:24	jonathanj	It seems (but perhaps I don't fully understand) like it would be annoying if a library logged stuff somewhere else when I don't want it to.
16:28	justin_smith	jonathanj: I don't really get logging but/and I find "annoying" a good description for all my interactions with things related to logging
16:29	jonathanj	I'm probing because I'm on the brink of porting a logger library to Clojure and I'd like a nice API.
16:30	osfameron	yeah, logging tends to be overcomplicated, overengineered and badly documented
16:30	jonathanj	I thought of having something like `(with-logger a-logger some forms)` rebind `logger`.
16:31	dysfun	i hope you didn't want some async with that because dynamic bindings are thread local
16:31	jonathanj	I was wondering about that.
16:32	justin_smith	I've been briefly enticed with ideas of software friendly logging (eg. every log is a json record including level and namespace etc. and the one reading the logs uses a client to filter and format)
16:32	dysfun	(in fact i use them in my single threaded cljs refs implementation)
16:32	jonathanj	So if any of those forms are async then I guess you need to wrap the logger at another level.
16:32	technomancy	justin_smith: how about https://brandur.org/logfmt
16:32	dysfun	justin_smith: i think riemann is a good base for that sort of thing
16:33	jonathanj	justin_smith: the library I intend on porting is http://eliot.readthedocs.io/ which might be an inspirational read then
16:33	justin_smith	technomancy: I've never seen that, interesting
16:33	technomancy	justin_smith: we used it heavily at heroku and it was <3
16:34	justin_smith	see, all these things are great, but they are improvements to a thing I find very unpleasant so my likelyhood of taking them on is lower
16:35	technomancy	the team I was on at heroku was literally the logging team =)
16:36	technomancy	it was an island of erlang in a sea of ruby/golang so I wasn't complaining
16:36	justin_smith	hah, nice
16:36	jonathanj	After having used Eiot for some complex logging, being able to visualise the hierarchy seems like a can't-go-back experience.
16:36	patchwork	justin_smith: I like your vision of logging. That is all it needs to be
16:37	dysfun	always fun to play with things like erlang
16:37	patchwork	(tears out swaths of logging code from project)
16:37	patchwork	technomancy: Are you anti-golang? Is golang the devil? I haven't tried it yet
16:37	patchwork	You used it in the same sentence as ruby so....
16:37	technomancy	patchwork: it's ... not a good programming language
16:38	patchwork	I have a coworker who is an evangelist of golang right now
16:38	patchwork	since I don't have any experience with it I don't really have a good response for the guy
16:38	dysfun	technomancy: diplomacy, you has it. i would be less polite about it than that
16:38	technomancy	we use it some at work and the only reason I can live with it is that no one is evangelistic about it
16:39	patchwork	What are the issues? I thought the goal towards concurrency and minimalism coincides with why I love clojure
16:39	patchwork	Like I said though, haven't tried it
16:39	technomancy	patchwork: it's very clearly designed by someone who hasn't done their homework around type systems, to say the least
16:40	dysfun	or on many other areas critical to it, like garbage collection
16:40	patchwork	Ah okay.... after working in scala for the past year I am starting to resent heavy type systems ; )
16:40	technomancy	like ... what's the most common type error by at least an order of magnitude? null references. so you would think then if you were designing a type system, handling null references would be the first thing you would encode into it? not in golang. =(
16:40	patchwork	but maybe that is just because of implicits
16:41	technomancy	scala at least has the interop excuse; golang has no excuse.
16:41	patchwork	Ah yes, null references
16:41	technomancy	"this is how we did it in the 1970s so it's probably the best way to do it"
16:41	patchwork	Something I have been very happy to do away with in scala
16:41	patchwork	haven't had one of those in a long time
16:41	patchwork	I see, funny!
16:41	dysfun	and whoever thought it was a good idea to make all the containers non-threadsafe in a highly concurrent language, well that's just a stroke of genius
16:41	l1x	golang is amazing i think interface{} is just a pretty nice way of saying go and fuck yourself and your types
16:41	patchwork	You think the google people would put someone more thoughtful on their signature language design team
16:42	technomancy	also "pass by value semantics" aka we are going to implicitly copy all values for every function call unless you opt out of it
16:42	dysfun	signature language? perhaps you mean dart?
16:42	technomancy	patchwork: famous is apparently an acceptable replacement for thoughtful
16:42	l1x	yeah that too
16:42	dysfun	technomancy: oh yes, it's definitely a replacement for C!
16:42	patchwork	Ah, I thought golang was their flagship
16:42	l1x	the lack of proper types bothers me more though
16:43	patchwork	Cool, so it is better than C
16:43	patchwork	Progress is good
16:43	l1x	like we did not have ocaml or any good languages with decent type systems
16:43	dysfun	patchwork: that was sarcasm
16:43	patchwork	Thanks for the summary!
16:43	l1x	patchwork: it is good for a single reason: CSP
16:43	technomancy	patchwork: my favorite way to describe golang's type system is it's like wearing a bulletproof vest with a big gaping hole over the heart. it's bulky and impedes your movement, but it doesn't actually protect your most vital organs.
16:43	l1x	:D
16:44	patchwork	dysfun: I don't know what sarcasm is anymore
16:44	dysfun	there isn't a hole to get into it because they don't support generic vests
16:44	l1x	well go is pretty good if you are a python programmer
16:44	l1x	hey look ma, i can ship a single binary!
16:44	dysfun	l1x: so one of my friends is currently writing cgo and FFIing from python...
16:44	l1x	there you go! :)
16:45	technomancy	l1x: it's funny how ruby and python people are so impressed by such a simple thing
16:45	dysfun	tbf it's a cool thing
16:45	dysfun	single artifact deployments are ace
16:45	osfameron	uberjars!
16:45	l1x	technomancy: yeah, they havent seen ocaml this is why
16:45	technomancy	dysfun: yeah but racket, ocaml, lua... this is not exactly a high bar
16:46	dysfun	sure
16:46	technomancy	it's just the jvm/python/ruby go out of their way to make things difficult
16:46	patchwork	It is for people who've never seen it before ; )
16:46	l1x	do you want a single binary? or do you want byte code? do you want union types? do you have Some(x) or None? Please be my gues
16:46	osfameron	is Rust more interesting?
16:46	l1x	guest*
16:46	technomancy	osfameron: by a long shot
16:46	l1x	yeah
16:47	l1x	it has almost all the great features of ml languages
16:47	technomancy	osfameron: the original rust compiler was written in ocaml, so you know it's designed by someone who hasn't been ignoring the last couple decades of research
16:47	l1x	yep
16:47	patchwork	I mean, right now the heavyweight nature of the JVM is a pretty big strike against it
16:48	patchwork	I am shipping a 300MB uberjar.... it raises some eyebrows
16:48	l1x	sure
16:48	osfameron	for some applications yeah
16:48	patchwork	Mostly of code I did not write
16:48	l1x	this is because many of the Java devs are morons
16:49	technomancy	it's a great fit for server-side code but not a one-size-fits-all by any means
16:49	l1x	http://mail-archives.apache.org/mod_mbox/orc-user/201702.mbox/%3CCAB25XEXALvkPWcG1mf6VRS-C0ZXvfdZGww-Bf-mgYiFo%2BhObaw%40mail.gmail.com%3E
16:49	l1x	story of today
16:50	dysfun	but rust has some horriblenesses
16:50	dysfun	like a constant deprecation cycle
16:51	l1x	yeah, i am not going to use it before it turns 10 years old
16:51	l1x	that is the qualifier for a programming language
16:51	dysfun	and the libraries are way too immature. they're trying to get the type safety and doing it at the cost of the flexibility you need from a systems language
16:51	dysfun	like don't even get me started about things like raw files last time i tried
16:51	technomancy	wait a minute...
16:51	l1x	:D
16:51	dysfun	wasn't clojure 2006?
16:52	dxtr	It takes 30 seconds to start the jvm on my other laptop. Just food for thought :p
16:52	technomancy	dysfun: I guess it depends on if you're counting from first commit or first public commit
16:52	l1x	First appeared 2007; 10 years ago
16:52	dysfun	dxtr: over a minute on a shitty box i borrowed last year when i was down on my luck
16:52	l1x	what?! :D
16:52	dxtr	dysfun: :D
16:52	dysfun	technomancy: close enough then :)
16:53	l1x	dxtr: well it is slow but once it is up!!
16:53	dysfun	yes and no
16:53	dxtr	l1x: Once the help text shows it shows it lightning fast!
16:53	patchwork	Well luckily you don't ever need to modify your code
16:53	dysfun	i swear too many silicon valley people think we're all running supercomputers
16:53	dxtr	dysfun: Are we not?
16:54	dysfun	"i write my shell scripts in clojure" "i don't have a minute to wait for them to start"
16:54	l1x	hahaha
16:54	l1x	actually ocaml is much better for "shell scripts"
16:54	justin_smith	dysfun: did you meantion you were working on a lumo fork at some point?
16:54	dysfun	yeah, there are some good libs for that
16:54	l1x	dxtr: have you tried a neutered jvm?
16:54	technomancy	dysfun: my personal laptop is a core 2 duo
16:54	justin_smith	l1x: yeah - you can even compile ocaml to machine code from source, then run it, fast enough :)
16:54	dxtr	Remember that time when you parallelized some stuff in ocaml?
16:55	l1x	justin_smith: yep exactly that
16:55	patchwork	Just wrote a script in planck a few days ago.... that is my new paradigm
16:55	technomancy	have been enjoying mostly writing luajit on that
16:55	dysfun	justin_smith: no. i am working on a build tool that uses lumo
16:55	dxtr	l1x: I have not
16:55	justin_smith	aha, now I get it - that's smart
16:55	technomancy	dxtr: the best thing about ocaml is it's like the mirror world of the jvm. low memory usage, terrible at concurrency, no %$@& nils, spock has a beard, etc
16:56	patchwork	Ah sigh.... so 2017, we still don't have the perfect programming environment
16:56	dxtr	technomancy: It can do concurrency fine
16:56	patchwork	Someone told me we would have this down by now
16:56	dxtr	technomancy: Parallelism on the other hand :)
16:56	patchwork	dxtr: Oh yeah? Just by spawning a new process and communicating over sockets?
16:56	l1x	technomancy: hahaha this is a perfect explanation
16:56	technomancy	dxtr: well I mean literal concurrency
16:56	justin_smith	patchwork: we might not have the perfect programming language, or flying cars, but you can get "croc martens" boots
16:56	l1x	but hey, concurrency is coming! :)
16:57	patchwork	Based on the way most people I see drive, I am super glad we don't have flying cars yet
16:57	l1x	well self driving flying cars
16:57	technomancy	patchwork: maybe we could wait till decent type systems become a bit more widespread before coding self-driving flying cars
16:58	dxtr	patchwork: Either that or you could just use the async package, for example.
16:58	l1x	btw. clojure got really fast over the years, lein repl is much faster to start up, lein uberjar is also more performant
16:58	technomancy	you put wings on that sucker and it better be written in Ada or an ML spinoff
16:58	l1x	i remember when lein repl took a decent amount of time
16:58	technomancy	lein repl is fast now? cool!
16:58	l1x	maybe because of java 1.8
16:59	l1x	technomancy: what do you use instead?
16:59	patchwork	Just started lein repl.... 5 seconds
16:59	l1x	since you wrote it, i bet you use lein :)
16:59	dysfun	3s here, but this is a nice machine
16:59	technomancy	l1x: I use lein inside docker-compose where it takes like five minutes to bring up the whole cluster
16:59	l1x	nice
17:00	dysfun	boot repl took 20s!
17:00	dxtr	Also, I started with clojure las week! Yay me, or something
17:00	l1x	dxtr: \o/
17:00	dxtr	I've been putting it off for years because jvm
17:01	l1x	dxtr: the best part is the community
17:01	l1x	like seriously
17:01	dysfun	dxtr: you learn to live with it. i was a massive java hater when i started with clojure
17:01	l1x	dxtr: the reason i started to use clojure because i could not even read java at the time
17:01	dxtr	dysfun: I have actually done Java professionally :p
17:01	l1x	dysfun: highfive
17:01	justin_smith	$ time java -jar ~/bin/clojure.jar -e '(System/exit 0)' => real 0m2.866s
17:02	dysfun	clojure is truly a breakthrough: it enables me to tolerate writing code that runs on the jvm
17:02	dxtr	I don't mind the jvm in itself. It's the bulkyness I dread
17:02	dysfun	i don't mind the jvm either, but the traditional way of programming it was java, which i do mind
17:02	l1x	dxtr: once in production this does not matter really
17:03	dysfun	even the java standard libraries aren't so bad driven with clojure
17:03	dxtr	What clojure needs is more templating, amirite?
17:03	l1x	most of our projects are 10-50MB uberjars where 95% is libraries not even needed but Java devs just add dependencies like trump outputs executive orders
17:04	l1x	dxtr: not sure
17:04	dxtr	:p
17:04	dysfun	(in particular i have to say AWT is a really nice API - transformation steps return new data rather than modifying in place)
17:04	l1x	i do not use too much templating
17:04	technomancy	if you can get over the horrid name http://docs.racket-lang.org/rackjure/index.html is a great way to write clojurey code without the huge jvm overhead
17:04	dxtr	l1x: I made a funny Java joke
17:05	dysfun	technomancy: they made ~> and ~>> more powerful than clojure's -> and ->> didn't they?
17:05	l1x	dxtr: no java jokes are funny :D
17:05	l1x	technomancy: racket does not have the libraries i need for my work
17:05	technomancy	dysfun: I hadn't heard that
17:05	dysfun	libraries are why i ended up sticking with clojure
17:05	l1x	this is why clojure is winning, there is a (shitty) java lib for everything
17:06	dxtr	l1x: Also, the worst part about Java stuff is the XML that surrounds it. I learned to hate a lot of things when I coded java at the job :p
17:06	l1x	dxtr: edn ftw
17:06	technomancy	l1x: well it's good to have options anyway
17:06	dxtr	Mainly XML and factory patterns
17:06	l1x	technomancy: true that
17:06	dysfun	i think most professional java devs know how to drive IDEs that generate boilerplate for them
17:06	l1x	how is CSP/concurrency in racket?
17:07	dxtr	dysfun: Which sucks when things break
17:07	technomancy	l1x: you get real threads, but the GC is stop-the-world. I would be surprised if there weren't a good CSP implementation but I don't know if it ships in the stdlib
17:08	l1x	i see
17:08	dxtr	well, Racket isn't really made to be performant, is it?
17:08	l1x	this is why i think lfe is a better direction
17:08	l1x	the erlang no global vm stop is just amazing
17:08	technomancy	dxtr: it's made serious strides in the past few years (especially on ARM) but nothing like the JVM
17:09	l1x	dxtr: last time i checked it was up in the same bracket with clojure in terms of http-hello-world-micro-benchmark-e-penis
17:09	technomancy	actually there was a brief window when racket could beat clojure on ARM performance
17:09	technomancy	when most of hotspot's jit smarts were x86-only
17:09	l1x	and it does not require a 160MB JVM
17:10	dysfun	l1x: i lost faith in lfe
17:10	dxtr	I just go with erlang
17:10	l1x	dysfun: how about joxa? :)
17:10	technomancy	joxa's design is great
17:10	l1x	dxtr: alright, erlang than! :)
17:11	dysfun	partially i think erlang is a nicer language, partially i'm not happy with some fundamental qualities of the erlang vm
17:11	l1x	i like erlang but i cannot find developers who i could work with
17:11	l1x	dysfun: like?
17:11	l1x	i really like beam
17:11	dysfun	for example the atom table
17:11	dysfun	we wrote some generative tests for lfe and it would exhaust the atom table and crash the BEAM
17:12	dysfun	and the fact that the builtins can't spawn processes and reliably recover if they close (they expect an EOF character!)
17:12	l1x	even when you configure it right?
17:12	dxtr	Well, to be fair, if you're generating that many atoms you should consider another data structure
17:12	dysfun	OS processes i mean, not erlang processes
17:12	dysfun	dxtr: hard to do generative tests involving atoms without generating lots of atoms
17:13	l1x	dysfun: these are sort of issues that either i dont care or if i had to care i could solve them
17:13	dxtr	dysfun: Just seems like a weird thing to do :p
17:13	dysfun	generative testing? yeah it is but it's great
17:14	l1x	By default, the maximum number of atoms is 1,048,576. This limit can be raised or lowered using the +t option.
17:14	l1x	there, easy to fix for a real world use case
17:14	dysfun	l1x: of course, but the solutions here involve reserving memory for a large atom table and shipping extra C
17:15	dxtr	Also, the vm is pretty slow
17:15	dysfun	compared to the jvm, sure
17:15	dxtr	Compared to most things?
17:15	dysfun	nah
17:16	l1x	dysfun: what is the usecase when 1,048,576 atoms are not enough?
17:16	dysfun	erlang compares favourably with dynamic langs
17:16	l1x	also erlang beats almost everything with template rendering
17:17	l1x	might not be true anymore
17:21	dysfun	templatewise, everyone uses erydtl
17:26	dysfun	technomancy: do you prefer racket or clojure?
17:27	technomancy	dysfun: depends on what I'm doing I guess. I wouldn't do server-side stuff in racket, and I wouldn't do guis and CLI tools in clojure (with the obvious exception of lein)
17:28	dysfun	i saw they're moving to chez scheme because it's faster
17:28	technomancy	dysfun: I feel like Racket has historically had the edge on "prevent flexibility from becoming an unmaintainable mess over time" but now that Racket contracts are becoming part of Clojure that advantage is likely to lessen.
17:28	technomancy	I'm one of the weird ones who has never cared about speed
17:30	justin_smith	technomancy: "slow code" - hammock developed artisinal quality algorithms
17:30	technomancy	apart from leiningen startup I have only once had to profile Clojure code because it was too slow
17:30	technomancy	justin_smith: on a thinkpad from 2008!
17:30	justin_smith	sounds like a pitch
17:34	technomancy	dysfun: just for the record when I was hanging out in the #racket channel I frequently brought up how silly it was that hash-tables aren't callable and how their "just get the latest version of that lib lol" dependency system worked was ill-advised, etc
17:35	technomancy	I bring it up here more to avoid the echo chamber effect than to convince people to stop using clojure =)
17:35	dysfun	heh
17:35	dysfun	we tend to be free with our criticism of clojure in here too
17:36	dysfun	racket ~> tries to fix that, btw
17:37	technomancy	dysfun: racket or rackjure?
17:37	dysfun	(~> foo 'a 'b) -> (dict-ref (dict-ref foo 'a) 'b)
17:37	dysfun	rackjure, sorry
17:37	technomancy	IIRC rackjure fixes callable hash tables in a way that is not related to ~>
17:37	dysfun	that also
17:38	dysfun	of course you pay a performance penalty for those checks
17:39	technomancy	which is why regexes still aren't IFn in clojure =(
17:39	l1x	i was profiling clojure several times and rewrote parts that were slow
17:39	dysfun	well, if we moved to protocols for everything like cljs did, we could
17:39	l1x	just to beat java devs like 100x
17:40	l1x	10x was not good enough for me :)
17:40	l1x	threading is a bitch :(
17:40	dysfun	but that's not particularly likely, i think
17:40	technomancy	dysfun: how do you implement protocols if you can't define functions yet?
17:41	dysfun	fall back to Runnable
17:42	l1x	one guy was trying to convince our ceo that the bottleneck was our network (10G/s) and i was surprised to figure out he used a single thread to do network IO to a remote datacenter
17:42	technomancy	then you can't declare any protocol functions that take args though, right?
17:42	dysfun	okay, Callable then
17:43	technomancy	IIUC the only reason you don't have circularity issues on JS is that you can change your initial protocol implementation once you've bootstrapped enough of the language
17:44	dysfun	i haven't looked into it. i can see there are difficulties, but i think it's a bit moot because it would be a huge compatibility-breaking change at this point
17:46	technomancy	some day I'll be able to (filter #"correct horse battery staple" passwords)
17:46	dysfun	that would be pretty neat
17:50	justin_smith	technomancy: I knew someone once who called this "exampling" - where a concept is sound but someone takes an example of the concept's usage and follows literally, and remains ignorant of the concept itself
17:51	technomancy	justin_smith: sounds like a useful term but I'm not seeing the connection
17:51	justin_smith	technomancy: "here is how you can create a high entropy string that is straightforward to remember"
17:51	technomancy	oh haha right
17:51	justin_smith	"oh, OK, I will always remember that one high entropy string you used!
17:51	justin_smith	"
17:52	justin_smith	which is like, pathologically against the original point :)
17:52	technomancy	https://xkcd.com/221/
17:52	justin_smith	that's another good example of exampling actually
17:52	clojurebot	I don't understand.
17:52	justin_smith	clojurebot: you wouldn't, dummy
17:52	clojurebot	Pardon?
18:06	fifi-v	how can I play sound in reagent? Need something equivalent to js `new Audio("...")' and `.play()' as demonstrated here http://stackoverflow.com/a/23395136
18:08	justin_smith	fifi-v: that's not reagent specific is it?
18:10	justin_smith	fifi-v: (js/Audio. "data.....")
18:10	justin_smith	(.play ...)
18:10	justin_smith	fifi-v: this will all use standard interop syntax, it's pretty simple and well documented and worth learning
18:14	dxtr	Is korma a good choice for postgresql stuff?
18:16	dysfun	depends what you need
18:16	dysfun	it doesn't have json operator niceties
18:16	dysfun	it's very good for bread and butter traditional queries
18:17	amalloy	korma is more of a naan and curry thing than bread and butter
18:18	dysfun	har har
18:18	technomancy	did someone pick up the development of korma? I thought it was abandonware for some time
18:19	amalloy	abandonware doesn't have to be brokenware
18:19	dysfun	it still works. it hasn't seen much action, but it's not total abandonware i think
18:19	amalloy	(i have no opinion about korma personally, i just don't really go for the "x hasn't been committed to in two months, therefore it must be garbage" attitude i see sometimes)
18:20	technomancy	amalloy: I was thinking more like 4 years but sure
18:20	dysfun	korma is okay for the 90%
18:20	dysfun	the limitations it puts on the remaining 10% triggered me to start building something more powerful though
18:24	dxtr	technomancy: Last commit was 11 days go, apparently
18:24	technomancy	cool
18:26	dxtr	So what do other people use?
18:27	Ardx	what does ! mean in clojure? Like if I had (set! ) does it denote that it will execute immediately (not lazy), or that it is a macro?
18:27	dxtr	side effects, if I'm not mistaken
18:28	dysfun	not safe inside dosync
18:28	Ardx	oh
18:28	dxtr	I was mistaken
18:28	dysfun	but that's only clojure core and some functions do not have the ! when they're not safe (it's presumed e.g. println is obvious)
18:33	Ardx	ugh emacs keeps puttign all my comment lines in the middle of the screen when I press return
18:34	technomancy	Ardx: use two semicolons for beginning-of-line comments
18:36	Ardx	oh yeah
18:36	Ardx	nice
18:48	justin_smith	dxtr: well, most things not safe in dosync are not safe because of a side effect
18:48	justin_smith	dxtr: dosync retries on conflict, and your side-effecting functions could be called N times
18:48	justin_smith	so, bigger picture, still mostly right :)
18:49	dxtr	Well, you've gotta really make sure your sides are affected
18:50	technomancy	I get the feeling "let's mark side-effects with a !" was something that seemed like a good idea early on but eventually was considered too much
18:51	dysfun	is that like "let's sprinkle io! in our code"?
18:55	justin_smith	at night, when I should sleep, I am haunted by the visions of all the code I should have wrapped in io!
18:56	dysfun	i believe you. millions wouldn't.
18:56	technomancy	early on a lot of the buzz around clojure was due to its STM
18:57	technomancy	which is quite remarkably good, but it's just not that frequently used
18:57	justin_smith	indeed
18:58	dysfun	well most of us build webapps which talk to a database. we just don't have much call for it
19:07	fifi-v	justin_smith: thanks
19:26	dysfun	so i'm reading an olde english book and all the 's' are 'f'. it's surprisingly demanding to parse
19:27	justin_smith	it's a separate ss that looks like an f but it has a tail on the lower left that an f doesn't have
19:27	justin_smith	iirc
19:27	TimMc	technomancy: Come for the STM, stay for the PDSs.
19:27	dysfun	justin_smith: nope
19:27	dysfun	https://archive.org/details/firstsixbooksofe00eucl
19:28	dysfun	flick to the introduction
19:29	dysfun	there is a less pronounced horizontal bar to the 's' than the 'f', but they're not double s because 'ssciences' in the first sentence
19:29	justin_smith	dysfun: https://en.wikipedia.org/wiki/Long_s
19:30	justin_smith	it is used for doubles, including if the second s is in the middle of the word
19:30	justin_smith	yes, super weird rule
19:31	justin_smith	wait, not doubles - just any lower case s not at the end of the word
19:32	technomancy	I remember on classic Mac they used to use that as shorthand for "folder"
19:32	justin_smith	technomancy: solder - it's a secret message
19:32	dysfun	what, a long s?
19:33	justin_smith	ſſſſſſſ
19:34	dysfun	https://ia800204.us.archive.org/BookReader/BookReaderImages.php?zip=/14/items/firstsixbooksofe00eucl/firstsixbooksofe00eucl_jp2.zip&file=firstsixbooksofe00eucl_jp2/firstsixbooksofe00eucl_0015.jp2&scale=2&rotate=0 # look at how beautiful this book is though
19:34	dysfun	despite the long ssssssss
19:35	justin_smith	yes, very nice
19:36	justin_smith	ſyſtem took me a moment
19:36	dysfun	fquare just looks so wrong
19:36	justin_smith	ſupercallifragiliſticexpealidocious
19:36	dysfun	"Befides the fuperior fimplicity"
19:38	dysfun	"lefs" is a tedious one
19:38	justin_smith	for fucks ſake
19:39	dysfun	but yeah, it surprised me how much effort it was to parse
19:40	dysfun	i suspect "correcting" that probably involves OCRing it and then spellchecking the OCR results because the OCR doesn't speak long S
19:52	Ardx	hah so cool you can do "lein new play-clj hello-world" and it downloads play-clj
19:53	dysfun	did your last language not have that?
19:54	Ardx	I'm used to c# and viual studio where there is a GUI on everything. I'm used to command line things never working quite right :>
19:54	dysfun	heh
19:55	justin_smith	Ardx: btw you can use clojure with CLR - it's even up to date and everything
19:55	dysfun	yeah, i was really surprised to see how well they've kept up to date
19:56	Ardx	Yeah I know, meaning to try out at some point
19:56	justin_smith	it doesn't have a clojure-centric tool like leiningen though
19:57	dysfun	yeah, i should add clr support to my lumo build tool when i get more time to hack on it
19:58	justin_smith	that would be awesome
19:58	dysfun	well the idea for me was that it shouldn't just build cljs
19:58	dysfun	because that would be lame
19:58	justin_smith	and putting the build tool in something that starts up fast (eg. lumo) is a great idea
19:58	dysfun	i want it to build all sorts of things so i can take my build tool wherever i go
19:59	justin_smith	dysfun: in this room, 10 years from now "hey I want to try clojure, does it have a lumo build plugin?"
22:58	iannnn	hiiiiiii