#clojure – 2016-05-10

2016-05-10

00:35	TEttinger	...yeah screw Kotlin. apparently I'm hitting a compiler bug that is scheduled to be fixed in 1.0.2, but there's no workaround currently?
00:50	tolstoy	Maybe just make a small inlein (or whatever) script and try the hardest problem and see what it looks like?
00:57	TEttinger	I guess. trying to remember what inlein is
00:58	TEttinger	ah, windows may make that tricky :)
01:02	tolstoy	Ah.
01:03	tolstoy	I guess I was advising what I wish I did more often: timebox a bit on the hardest problem and see what it looks like.
01:03	tolstoy	Helps if you know the problem, I guess.
01:54	ilevd	dysfun, mpg raise an error java.lang.IllegalArgumentException: No matching clause: int4 then I'm trying insert {:a 1 :b 2} to jsonb field
01:54	ilevd	*when
02:03	dysfun	ilevd: hrm?
02:04	dysfun	paste code?
02:05	ilevd	(reference.data.pages/add-page (:jdbc t1) "4" "class" "url" {:a 1 :b 2} )
02:05	ilevd	IllegalArgumentException No matching clause: int4 mpg.data/patch/fn--19517 (data.clj:47)
02:06	ilevd	(insert! jdbc :pages {:url url
02:06	ilevd	:type type
02:06	ilevd	:content content
02:06	ilevd	:full_name url
02:06	ilevd	:version_id version-id}))
02:06	dysfun	can you pastebin enough code that i can make it fail please?
02:07	ilevd	Sec
02:09	dysfun	and i have literally just woken up, so bear with me :)
02:11	amalloy	you have a (case ...), where the value being dispatched on is "int4", or something that prints like that, and there's no clause in the case matching it
02:14	dysfun	thing is, as that's during insertion, it should be taking the type (against which the case is performed) from jdbc
02:15	dysfun	https://github.com/mpg-project/mpg/blob/master/src/mpg/data.clj#L47
02:17	dysfun	the only way i could see that failing was if you tried to shove a map in an int column
03:13	ilevd	dysfun, https://www.refheap.com/118885
03:14	ilevd	Something wrong with order when using jsonb
03:17	dysfun	thanks, let me play with it a bit
03:17	ilevd	*without "references .."
03:30	dysfun	sorry, what precisely is 'jdbc' here?
03:30	dysfun	i wrapped the clojure.java.jdbc api so i didn't have to deal with all the intricacies
03:32	ilevd	#reference.components.jdbc.JDBC{:config {:subprotocol "postgresql",
03:32	ilevd	:subname "//localhost:5432/db",
03:32	ilevd	:classname "org.postgresql.Driver",
03:32	ilevd	:user "user",
03:32	ilevd	:password "pass",
03:32	ilevd	:stringtype "unspecified"},
03:32	ilevd	:conn {:datasource #object[com.mchange.v2.c3p0.ComboPooledDataSource
03:32	ilevd	0x28be5ba2
03:32	ilevd	"com.mchange.v2.c3p0.ComboPooledDataSource[ identityToken -> z8kfsx9g16hbakekppxyi\|28be5ba2, dataSourceName -> z8kfsx9g16hbakekppxyi\|28be5ba2 ]"]}}
03:32	luma	please use pastebin or similar instead of pasting directly to the channel
03:32	dysfun	okay, in future please pastebin anything longer than a couple of lines
03:33	ilevd	Ok)
03:33	dysfun	https://gist.github.com/jjl/0f71cbbecf8169d51366aaf624c31ae9
03:34	dysfun	this is why i find jdbc infuriating
03:39	namra	greetings
03:39	ronbonert	no u
03:45	namra	i want to write some tests for an http api that uses compojure as a routing library and ring-mock to mock http requests but i get the following error (with example code): http://pastebin.com/7Eric6SK
03:53	kwladyka	namra as i see you try to mock the route, you should use some url to also test a route. Like in the original example https://github.com/ring-clojure/ring-mock
03:54	kwladyka	namra just see what request return, it will help you a lot
03:54	namra	kwladyka: thanks alot
03:55	namra	but the problem was caused by a (reload!)
03:55	namra	running 'lein ring server'
03:55	namra	and as soon as i change something and do a reload
03:55	namra	the tests fail with that error
04:06	hamid	:O
04:11	dysfun	how is it that postgres can have versions of every docs ever live for the database but only HEAD docs for the jdbc bindings?
04:12	dysfun	i mean who the hell is deploying an under-development release of postgres to production?
04:12	dysfun	or the jdbc drivers even
09:38	Rovanion	A function of mine takes a map. I want to check if the map contains a key - and then replace it with something else - before passing on the map. So (when (contains? map :key) do what exactly?)
09:40	ridcully_	you want to replace the key or the value?
09:41	Rovanion	The value.
09:41	ridcully_	assoc
09:41	Rovanion	Thanks!
09:43	ridcully_	but note, when using `when` you return nil, if the key is not there
09:48	justin_smith	yeah, (if (contains? m k) (assoc m k v) m) is probably what you want
09:49	Rovanion	Yes, that looks more like it. Thank you both!
09:50	justin_smith	,(let [m {:a 0}] (cond-> m (contains? m :a) (assoc :a :foo) (contains? m :b) (assoc :b :bar))) ; if you are doing this with multiple keys
09:50	clojurebot	{:a :foo}
09:53	Rovanion	Ah, a chaining of conditions all evaluated independently.
09:54	justin_smith	the conditions are independent, but the transforms are additive (if applied)
09:54	justin_smith	,(let [m {:a 0 :b 1 :c 2}] (cond-> m (contains? m :a) (assoc :a :foo) (contains? m :b) (assoc :b :bar))) ; if you are doing this with multiple keys
09:54	clojurebot	{:a :foo, :b :bar, :c 2}
09:55	Rovanion	Cool
09:56	abrunberaud	Yop
10:10	dysfun	https://gist.github.com/jjl/d92dc6f7675cd23d0f1c870e72443f8f # finally finished my monster of a macro faking the state monad
10:13	justin_smith	dysfun: what about replacing (map #(symbol (str "r" %)) (range (count clauses))) with (repeatedly (count clauses) #(gensym "r"))
10:14	dysfun	ooh that would shorten it
10:15	justin_smith	also wouldn't break if the user had symbols like r0 in their form
10:15	justin_smith	,(gensym "r")
10:15	clojurebot	r27
10:15	justin_smith	haha, well
10:15	dysfun	yes, though i considered it unlikely
10:16	dysfun	and it makes it more annoying verifying the correctness for output :)
10:16	justin_smith	,(= r28 (gensym "r"))
10:16	clojurebot	#error {\n :cause "Unable to resolve symbol: r28 in this context"\n :via\n [{:type clojure.lang.Compiler$CompilerException\n :message "java.lang.RuntimeException: Unable to resolve symbol: r28 in this context, compiling:(NO_SOURCE_PATH:0:0)"\n :at [clojure.lang.Compiler analyze "Compiler.java" 6688]}\n {:type java.lang.RuntimeException\n :message "Unable to resolve symbol: r28 in this conte...
10:16	justin_smith	ergh
10:16	justin_smith	,(= 'r28 (gensym "r"))
10:16	clojurebot	false
10:16	dysfun	and i just realised i can replace the (gensym "state") with `state#
10:16	justin_smith	that's a good one too
10:17	dysfun	okay, well it still appears to work :)
10:18	dysfun	https://gist.github.com/jjl/d92dc6f7675cd23d0f1c870e72443f8f
10:18	dysfun	(same gist)
10:18	justin_smith	👍
10:19	dysfun	nice. apparently lxterminal doesn't like unicode
10:19	justin_smith	it was just a thumbs-up
10:19	dysfun	it's still long and ugly
10:21	justin_smith	dysfun: what about postgrey.squirrel.util/init - I would expect to see 123 instead of that
10:21	dysfun	aha yes
10:22	dysfun	i was about to use it, so i'd have soon found that ;)
10:22	justin_smith	dysfun: I don't think there is any symbol to qualify in that form starting on line 21 - it's all values generated in the containing let, so you don't need ` there
10:22	justin_smith	though ~@ can be handy
10:22	dysfun	yes, i'm quoting precisely because of interpolation
10:23	dysfun	it's like a sort of fucked up template language
10:23	justin_smith	haha
10:24	dysfun	okay, now interpolating the initial value as well
10:24	dysfun	and all looks good enough for actually trying to use it
10:24	dysfun	then again i said that a minute ago...
11:45	sdegutis	Why come this does not work,
11:46	sdegutis	,(> (java.util.Date.) (java.util.Date.))
11:46	clojurebot	#error {\n :cause "java.util.Date cannot be cast to java.lang.Number"\n :via\n [{:type java.lang.ClassCastException\n :message "java.util.Date cannot be cast to java.lang.Number"\n :at [clojure.lang.Numbers gt "Numbers.java" 229]}]\n :trace\n [[clojure.lang.Numbers gt "Numbers.java" 229]\n [sandbox$eval25 invokeStatic "NO_SOURCE_FILE" 0]\n [sandbox$eval25 invoke "NO_SOURCE_FILE" -1]\n [cloj...
11:46	luma	> can only compare numbers
11:46	justin_smith	compare, on the other hand
11:47	justin_smith	,(compare (java.util.Date.) (java.util.Date.))
11:47	clojurebot	0
11:49	sdegutis	,(->> #(compare (java.util.Date.) (java.util.Date.)) (repeatedly 100000) (distinct))
11:49	clojurebot	(0 -1)
11:49	sdegutis	haha clojure you so craaazay
11:49	sdegutis	So, you know about Ken M right?
11:49	justin_smith	of course
11:50	justin_smith	best idiot ever
11:50	sdegutis	It doesn't work so well on Reddit https://www.reddit.com/user/___kenm
11:51	sdegutis	They're too good of a target audience, they just downvote him, which hides his comments.
11:51	sdegutis	It only works on Yahoo News and Facebook because comments are listed there in chronological order.
11:52	sdegutis	I wonder if Datomic's < and > use (compare) internally.
12:02	ilevd	<offtop> Elm 0.17 is appeared http://elm-lang.org/blog/farewell-to-frp </offtop>
12:02	sdegutis	Why doesn't Clojure's > and < use compare internally?
12:02	ridcully_	,(.before (java.util.Date. 0) (java.util.Date.))
12:02	clojurebot	true
12:02	sdegutis	Also <= and => that would make it nicer.
12:03	sdegutis	ridcully_: unfortunately there is no .beforeOrEqual, it just must be .before with the arguments reversed
12:03	justin_smith	sdegutis: the numeric method is faster
12:03	sdegutis	or (or (.before) (.equal))
12:03	sdegutis	justin_smith: now I understand this
12:06	ridcully_	,(>= (.getTime (java.util.Date.)) (.getTime (java.util.Date.)))
12:06	clojurebot	true
12:16	OscarZ	is there something like (if-not-nil (myfunc xxx) default-value) which would evaluate to (myfunc xxx) if its not nil, and otherwise to default-value ?
12:17	luma	there's (or (my-func xxx) default-value, but that also evaluates to default-value if (myfunc xxx) is false (in addition to nil)
12:18	OscarZ	thanks luma, i think that works for me
12:18	justin_smith	OscarZ: also, there is fnil
12:18	justin_smith	,((fnil inc 0) nil)
12:18	clojurebot	1
12:18	justin_smith	,((fnil inc 0) 2)
12:18	clojurebot	3
12:21	OscarZ	justin_smith, yeah was looking at fnil but didnt understand it first.. now i do :)
12:27	justin_smith	OscarZ: the only difference from what you asked for is that it returns a new function, and you provide a default input, not a default result
12:28	OscarZ	so fnil identity would be what i want?
12:30	OscarZ	yes, seems to work
12:31	justin_smith	but or is more straightforward than (fnil identity default)
12:31	OscarZ	i was sure there was something like what i asked as "nil" seems to be pretty special value and often used like that... i guess "or" is very close though
12:56	sdegutis	justin_smith: wow another use for fnil
12:56	sdegutis	OscarZ: will myfunc ever return false?
12:59	sdegutis	I've not once used fnil in my code. It's usually overkill because false rarely turns up alongside nil.
12:59	sdegutis	Oh wait, no, we use fnil three times.
12:59	sdegutis	But every single time it's (fnil inc 0)
13:00	dysfun	fnil fnil fnil? is that like flatmap flatmap flatmap?
13:00	justin_smith	sdegutis: (fnil conj #{}) and (fnil conj []) are also very useful
13:00	sdegutis	justin_smith: hmm interesting
13:02	justin_smith	,(reduce (fn [m [k v]] (update m k (fnil conj #{}) v)) {} '[[a 0][b 1][b 2][a 0][c 3]])
13:02	clojurebot	{a #{0}, b #{1 2}, c #{3}}
13:16	sdegutis	justin_smith: I wonder if reduce-kv can be used there
13:16	justin_smith	sdegutis: well, the input isn't a value hash-map
13:16	justin_smith	(and wasn't meant to be)
13:20	sdegutis	ok
13:27	sdegutis	Mustery solved:
13:27	sdegutis	Found in stack trace: java.util.Date/compareTo, clojure.lang.Util/compare, datomic.extensions/<
13:27	sdegutis	Hooray
13:29	dysfun	those bizarre errors sure do sell datomic to me
13:29	sdegutis	dysfun: no no that's me truncating the stack trace to show the lineage
13:30	sdegutis	dysfun: (cont'd) lineage which proves that < does in fact use clojure's compare function
13:31	sdegutis	well not technically, but basically
13:31	sdegutis	since clojure.core/compare uses clojure.lang.Util/compare internally
13:31	dysfun	you know, in several channels i hang out in, if you said "well not technically, but basically", someone would change the topic to quote you and embarrass you
13:33	justin_smith	sdegutis: datomic's < you mean
13:34	sdegutis	in my cont'd statment yes
13:34	sdegutis	dysfun: how is that embarrassing
13:34	sdegutis	i mean, yes, we all know technically correct is the best kind of correct
13:34	sdegutis	but basically correct is also acceptable often
13:35	dysfun	well it seems to me that this is quite clearly a falsificable fact, ergo they're the same thing
14:08	ben_vulpes	if anyone's looking for short-term contract work, i'd like a hand with a postback clojure app over the next 4 weeks. PM for details, introductions happily accepted. local to portland would make me giddy, although possible to work around.
15:31	{blake}	You know, I had it in my head that that one was going to happen in 2016 or 2017. Couldn't figure out why I hadn't heard anything abou it.
15:31	kwladyka	anybody with good emacs experience and Intellij Idea + Cursive can say something clever? :) I consider to learn emacs, because it is like religion.... society demand it in some way, it determine how others see you :) If you use emacs you are pro :) Bla bla... back to my question, somebody use both and can say something in topic?
15:31	ridcully_	you might have confused 2017 with 2037
15:31	ridcully_	or some windows version goes boom soon
15:31	marcy--	can someone tell me how to get a clojure repl up with a dependency without relying on lein/boot? calling `require` after `java -cp "clojure.jar:dependency.jar" clojure.main` is not working.
15:31	{blake}	ridcully: Yeah, might be. There's some kind of twist on the Mayan-end-of-the-world thing that falls on 2017, too.
15:32	justin_smith	marcy--: that works, if all your deps are in that cp
15:32	justin_smith	marcy--: for example, you probably want the directory with your source-files to be in that cp arg
15:32	justin_smith	eg java -cp clojure.jar:src:dependency.jar clojure.main
15:32	justin_smith	the "" is not needed
15:33	justin_smith	(unless your deps paths have wierd names, of course)
15:33	engblom	kwladyka: I am in the minority as I do not use Emacs for programming. I have many times been giving it a chance and it is very decent for developing programs in any Lisp dialect. Personally I am using the "rivalling" editor which is called vim.
15:34	engblom	kwladyka: Regardless if you go with emacs or vim (both are getting the task done), you will have to experience a steep learning curve that will pay off later
15:40	justin_smith	require only works with an ns form, otherwise (load-file ...) will handle anything you throw at it
15:40	justin_smith	anything that would work in a repl, of course
15:41	justin_smith	one could also nitpick about file not being bound, and that thing that makes gen-class work...
15:42	dysfun	yeah, so it's actually not all that clear cut