#clojure – 2013-04-23

2013-04-23

00:47	talios	shiny
03:47	NeedMoreDesu	how do you do nested loops?
03:47	ucb	,(doc for)
03:47	clojurebot	"([seq-exprs body-expr]); List comprehension. Takes a vector of one or more binding-form/collection-expr pairs, each followed by zero or more modifiers, and yields a lazy sequence of evaluations of expr. Collections are iterated in a nested fashion, rightmost fastest, and nested coll-exprs can refer to bindings created in prior binding-forms. Supported modifiers are: :let [binding-form expr ...], ...
03:47	ucb	NeedMoreDesu: you could try with for
03:48	NeedMoreDesu	If I wish to loop for (< i n) ?
03:49	NeedMoreDesu	ofc I can make lazy list of increases lol
03:49	ucb	NeedMoreDesu: you can map over (range n)
03:49	NeedMoreDesu	Is it lazy?
03:49	jaen	fzz
03:50	ucb	both map and range are
03:50	NeedMoreDesu	oh, nice.
03:50	jaen	;;--
05:23	linux_	Buy Korean stuff, all is well
05:32	silasdavis	how should I go about debuggin a ring-based application
05:33	silasdavis	I'd like to be able to break on a line and inspect variable values
05:33	clgv	silasdavis: first there is a middleware that prints you the encountered exceptions in a readable way
05:33	silasdavis	or at least see a trace of arguments
05:33	silasdavis	clgv, I think I'm seeing that (I get a stacktrace in the browser)
05:34	silasdavis	something like:
05:34	silasdavis	APersistentVector.java:265 clojure.lang.APersistentVector.invoke
05:34	silasdavis	friend.clj:196 cemerick.friend/authenticate*
05:34	silasdavis	friend.clj:208 cemerick.friend/authenticate[fn]
05:42	zackzackzack	How should I go about typing hinting methods that don't take any arguments?
05:44	mpenet	it seems like you want to type the instance
05:56	piranha	it seems there is no easy way to check if string contains a substring, right?
05:57	ejackson	piranha: use a regexp
05:58	ucb	piranha: alternatively use .substring
05:58	ejackson	,(re-find #"substring" "string with substring")
05:58	clojurebot	"substring"
05:59	piranha	ejackson: I also thought about (if-not (neg? (.indexOf str substr)))
05:59	ucb	lovely
05:59	ejackson	although ucb is right, .substring should be faster
05:59	piranha	but still, no simple clojure.string/contains?, eh
06:00	piranha	well, substring is like a slice, I need .indexOf
06:01	Ember-	,(.indexOf "my merry string" "merry")
06:01	clojurebot	3
06:01	Ember-	what's wrong with that?
06:01	Ember-	clojure does not try to invent the wheel again where java suffices
06:02	piranha	well, I have to check for -1, instead of true/false, which makes a lot more parens :)
06:02	Ember-	so you need index number except if there is no such substring in which case it should return false?
06:03	ucb	,(.substring "foo" "foobar")
06:03	Ember-	or do you just need true/false if there is such a string?
06:03	clojurebot	#<ClassCastException java.lang.ClassCastException: java.lang.String cannot be cast to java.lang.Number>
06:03	ucb	orly
06:03	ucb	,(.subString "foo" "foobar")
06:03	clojurebot	#<IllegalArgumentException java.lang.IllegalArgumentException: No matching method found: subString for class java.lang.String>
06:03	ucb	bleh
06:06	ucb	piranha: (defn str-contains? [s1 s2] (.contains (.toLowerCase s1) (.toLowerCase s2)))
06:06	ucb	,((fn str-contains? [s1 s2] (.contains (.toLowerCase s1) (.toLowerCase s2))) "foobarbaz" "foo")
06:06	clojurebot	true
06:43	piranha	Ember-: yes a true/false, yes
06:44	ucb	piranha: see above
06:44	piranha	ucb: yep, I could have a simple helper
06:44	piranha	sure, thanks
06:44	ucb	np :)
06:44	piranha	I haven't realized java has .contains on a string
06:45	piranha	was looking at some funny (and outdated) documentation :\
06:56	jjl`	ugh, i've just spent an hour figuring out why my code doesn't work and it's a hiccup bug. where can i report it?
07:01	tcrayford	jjl`: I'd assume on github
07:04	jjl`	ta
07:07	jjl`	heh, someone else already reported it
07:55	clgv	what am I doing wrong when I use `applet` from "quil" and additional window with title "Quil 1" opens in addition to the one I added the applet to?
08:12	piranha	alandipert: octagon: are any of you guys here by any chance? :)
09:40	TimMc	&(hash-map "\u00e9" "c" "\u0065\u0301" "d")
09:40	lazybot	⇒ {"é" "c", "é" "d"}
09:41	TimMc	What Unicode normalization form should I use before hashing a password?
09:42	TimMc	I'm inclined towards NFKD, although http://unicode.org/reports/tr15/#Norm_Forms says "Normalization Forms KC and KD must not be blindly applied to arbitrary text."
09:44	TimMc	I should really take that to StackOverflow.
09:45	pjstadig`	NFC
09:46	TimMc	I'm concerned that the NFC form might change if a future Unicode spec adds a composite form.
09:47	TimMc	s/form/character/
09:49	pjstadig`	so you use the stable version of NFC
09:50	pjstadig`	NFKD means that people could enter two different passwords and have them hash the same because they would decompose into the same sequence of code points
09:51	pjstadig`	http://unicode.org/reports/tr15/#Versioning
09:51	TimMc	Ah, the stability thing is new to me.
09:52	TimMc	I'm pretty sure any of the normalization forms have collisions. That's what normalization is, yeah?
09:53	TimMc	,(.importClass ns 'Norm java.text.Normalizer)
09:53	clojurebot	java.text.Normalizer
09:53	pjstadig`	i suppose that's true, someone could enter two separate characters that would get composed under NFC
09:53	TimMc	,(.importClass ns 'NF java.text.Normalizer$Form)
09:53	clojurebot	java.text.Normalizer$Form
09:53	pjstadig`	not sure if java.text.Normalizer supports stable normalization or not
09:54	TimMc	Yeah, I don't see a way to do that.
09:55	TimMc	But the D or KD forms should be stable, right?
09:57	pjstadig`	actually i think annex #15 defines normalization in terms of the 3.1.0 unicode database, which means the JVM implementation of annex #15 should be stable
09:57	pjstadig`	with respect to Unicode 3.1.0
09:58	TimMc	Do you see any harm in D or KD?
09:59	TimMc	The "must not" scares me, but there's no need for round-tripping or preservation of semantics.
10:00	TimMc	I'm OK with "oﬃce" -> "office"
10:01	pjstadig`	i think the non-round-tripping and non-preservation of semantics is why the recommend not using with arbitrary text
10:01	pjstadig`	if you know that, then maybe you'll be ok
10:12	xorola	Hey guys, i got a question. In what ways clojure macros differ from C macros and Other lisp macros ? a resource would be great .
10:13	tcrayford	principally, clojure macros operate on data structures, C macros operate on strings
10:13	tcrayford	http://clojure.org/macros
10:14	tcrayford	they are very similar to common lisp macros (though there's only one namespace, which makes things a bit different)
10:17	stuartsierra	To clarify tcrayford's comment, Common Lisp has separate symbol tables (namespaces) for functions and normal variables, called a "Lisp-2." Clojure does not, called a "Lisp-1." Clojure also has a language feature called "namespaces" which are something completely different.
10:18	tcrayford	stuartsierra: oops. Thanks
10:18	stuartsierra	tcrayford: No problem. Just saw an opportunity for confusion there.
10:21	xorola	tcrayfod: i have been through that link? it is still vague to me where should i use macros? I want to see a compelling use case where macros only solves the problem or macros is the way to go? any source code link?
10:22	stuartsierra	Macros are most-often used for language extensions. For example, many parts of Clojure itself are implemented as macros.
10:23	tcrayford	see clojure.core/defn for an example (though a noticeably hairy one)
10:24	tcrayford	in fact, searching this file: https://github.com/clojure/clojure/blob/master/src/clj/clojure/core.clj for defmacro will give you a host of examples
10:25	stuartsierra	Macros are rarely used in application-level programming, but they are a very powerful tool for extending the language.
10:27	TimMc	xorola: Macros are never the only way to solve a problem.
10:30	xorola	TimMc: fair enough, :)
10:33	TimMc	pjstadig`: Drat. I just read the part of the spec about stabilized strings. Even the D and KD forms need stabilization in the face of new characters.
10:33	pjstadig`	TimMc: right, but annex #15 is stable
10:39	TimMc	pjstadig`: You're talking about "3. Versioning and Stability", right? That only seems to cover assigned characters. I'm trying to understand how a Unicode N-aware system would handle normalization of characters introduced in Unicode N+1.
10:41	murtaza52	I have a structure - [+ 1 2 3 [- 4 3] 5 6 [- 9 8]]. In which if the form is a vector, then the first element is a fn and rest its args. How do I write a fn to eval it ?
10:42	gtrak	murtaza52: I recommend multimethods
10:43	gtrak	I wrote a similar little interpreter the other day: https://github.com/gtrak/webbedfeet/blob/master/src/com/garytrakhman/webbedfeet.clj
10:44	gtrak	stack-based
10:44	pjstadig`	TimMc: the way i read annex #15 it defines The Normalization Process™ and if someone claims to support that annex they normalize against the Unicode 3.1.0 database
10:44	pjstadig`	Unicode N will continue to normalize according to annex #15, which means against the 3.1.0 Unicode database
10:45	TimMc	Hmm. So no new compositions are allowed, then?
10:45	pjstadig`	not according to annex #15, if i'm reading it right
10:46	cmajor7	can't get flatland https://github.com/flatland/clojure-protobuf extensions to work: https://www.refheap.com/paste/13884 anything I am missing? thx
10:46	pjstadig`	TimMc: maybe annex #nn will define normalization process 2.0 against a new version of the unicode database, but for now if anyone claims to support unicode normalization, they support it against the 3.1.0 database
10:47	TimMc	"However, the Unicode Consortium strongly discourages new compositions, even in such restricted cases."
10:47	TimMc	I guess that works.
10:48	pjstadig`	right, they're saying that if they add a new composition character, it will be a composition of two new characters to a new composition character, which means it could not upset previously normalized text
10:50	TimMc	My concern is where the client sends newer characters than the server's Unicode support understands.
10:50	TimMc	Just reject it, maybe? :-/
10:51	TimMc	For that matter, I suppose byte sequences invalid for UTF-8 (or whatever) mus tbe rejected.
10:54	pjstadig`	i think any newer characters would just pass through the normalization process
10:54	TimMc	I'd be willing to say "the server always has a recent Unicode".
10:55	pjstadig`	there's a closed set of characters that the normalization process detects and (de)composes, anything else just passes through
10:56	TimMc	Perhaps then an NF(K)C form is preferable.
10:57	TimMc	Let's say the year is 2015. The server is at Unicode 6.1, and the client registers with a Klingon password. It is full of unassigned characters, and passes through normalization unchanged. Later that yearm the server is updated, and starts performing normalization on that password. The hash no longer matches.
10:58	TimMc	(The client here is at Unicode > 6.1 or whatever the current version is.)
10:58	pjstadig`	normalization is defined against the unicode 3.1.0 database
10:58	pjstadig`	it is frozen forever
10:59	pjstadig`	you will never get different results for a newer version of Unicode
10:59	TimMc	Oh! "A normalized string is guaranteed to be stable; that is, once normalized, a string is normalized according to all future versions of Unicode."
10:59	pjstadig`	(after 4.1)
10:59	TimMc	That's a pretty strong guarantee.
11:00	TimMc	Actually, "For all versions, even prior to Unicode 4.1, the following policy is followed:"
11:00	TimMc	^
11:00	TimMc	"strongly discourages new compositions" is a weaker statement.
11:04	TimMc	Ugh, that "and contains only characters allocated in that version" still bothers me. :-/
11:05	TimMc	"If an implementation normalizes a string that contains characters that are not assigned in the version of Unicode that it supports, that string might not be in normalized form according to a future version of Unicode."
11:08	ToBeReplaced	if i have a callback function being called asynchronously in a thread, how can I use that callback to create a lazy-seq in main?
11:08	joegallo	create a promise and have the other thread deliver on the promise
11:08	joegallo	for instance
11:09	ToBeReplaced	joegallo: what type gets delivered?
11:09	joegallo	whatever you put into it...
11:14	ToBeReplaced	joegallo: so would you create a seq of promises in an atom, have the thread deliver them in order, then have main deref them as it goes?
11:15	joegallo	i would promise to return a lazy-seq, and then i'd return a lazy-seq
11:15	joegallo	or are you trying to get into a producer and consumer?
11:19	ToBeReplaced	consumer producer; i have a service subscription that hits a callback in a separate thread; i want to view that subscription as a lazy-seq instead so that a doseq can run forever
11:28	TimMc	pjstadig`: Thanks. I've collected what I learned into a SO post: http://stackoverflow.com/questions/16173328/what-unicode-normalization-and-other-processing-is-appropriate-for-passwords-w/
11:33	pjstadig`	TimMc: with recommendation #1 what you are saying is you want NPSS http://unicode.org/reports/tr15/#Stabilized_Strings
11:33	pjstadig`	which is fine, i just wanted to point out that annex #15 handles that case (if you hadn't seen)
11:38	TimMc	Thanks, yes.
11:42	mynomoto	I'm trying to detect repetition in code. I would like to make the expressions generic so (string? abc) is converted to something like (string? x). Any ideas of how to do that?
11:43	aphyr	mynomoto https://github.com/clojure/core.match + a macro?
11:45	clgv	I cloned Clojure's `future` implementation to be able to exchange the threadpoolexecutor which is bound in a dynamic variable. when using clojure.core/binding-conveyor-fn in the `future-call` implementation I always get nil as result. when I remove `clojure.core/binding-conveyor-fn` then it works as expected. why?
11:46	tcrayford	mynomoto: I did something like this a while back (it almost definitely won't run anymore): https://github.com/tcrayford/umbrella
11:46	tcrayford	the source there might be useful, it's not too long
11:47	ucb	clgv: is your implementation of future available anywhere?
11:47	ucb	(I just happen to have a need for such thing :) )
11:48	clgv	ucb: I can make it available. but first it needs to work. it would be a shame to loose future's sematic with respect to thread-local-bindings...
11:49	ucb	clgv: nod
11:51	mynomoto	aphyr: Thanks.
11:52	mynomoto	tcrayford: I will look at the source, looks like what I'm looking for.
11:52	tcrayford	myonmoto: iirc it's kinda fucked in it's current state. But you can probably get some ideas from there
11:52	tcrayford	(as in, even if the code ran, it'll be broken)
11:58	noncom	hi! I have a jar which depends on other jars in the same folder. how do i instruct leiningen to push it to clojars correctly, specifying which is the mainjar and which are dependencies?
11:58	mynomoto	tcrayford: I'll try to run but the transmogrification appear to be what I want.
12:04	andrew__	does anyone have experience using server-socket (https://github.com/technomancy/server-socket/blob/master/src/server/socket.clj) to eventually write binary files? It defaults to using an OutputStreamWriter but I'm wondering if I can change it to using something different that might make serving up binary files a little bit easier (sorry, I'm really new to all of this so I'm probably not explaining too well)
12:09	nz	~.
12:09	clojurebot	Cool story bro.
12:09	nz	ls
12:09	lazybot	bin boot sbin srv swap
12:10	noncom	a question about clojars: I have a jar which depends on other jars in the same folder. how do i instruct leiningen to push it to clojars correctly, specifying which is the mainjar and which are dependencies?
12:10	noncom	do i have to create a correct pom for that with dependencies section?
12:12	S11001001	noncom: what are these "other jars"?
12:15	noncom	S11001001: i'm trying to push the Minim sound library (https://github.com/ddf/Minim). Those extra jars are it's dependencies. The library is written in java and has no pom descriptors...
12:15	noncom	there is a 3-year old push on clojars, in (https://clojars.org/org.clojars.automata/ddf.minim/versions/2.1.0) but that version is outdated
12:17	S11001001	noncom: I don't think maven supports an arbitrary set of jar artifacts for a particular artifactid. As with the link you just posted, each one needs to be pushed, so you have a dependency graph known to maven & its clients. Good news is you can just grab the poms there already and update them for your push.
12:20	nz	noncom: or you could have a hierarchy of pom.xmls and parent pom.xmls, then you can push jars from whole hierarchy to maven repo.
12:20	joegallo	from https://github.com/technomancy/leiningen/wiki/Repeatability, you should open a bug with the project to ask them to get their work into the maven central repo
12:20	joegallo	that's the long term correct answer
12:21	nz	I don't if lein and clojars support project hierarchies
12:21	check123`	hey, are there any books written specifically for beginning programmers based upon clojure?
12:22	david_pidcock	Just out of interest -- I"m working on a little Grails thing using their web flow plugin. At the same time I'm learning Clojure and getting feet wet with Luminus -- does the concept of a Web Flow even make sense in a Functional language? If so, have there been any efforts to create one in Clojure?
12:22	david_pidcock	Couldn't find anything on the web yet.. :D
12:24	clgv	ucb: ok I found the error
12:24	ucb	clgv: oh?
12:27	noncom	nice! thank you for the answers. I have open the bug on the project and I will try to push the jars to my Clojar group for the meanwhile
12:28	clgv	usb: https://gist.github.com/guv/5445115
12:28	clgv	ucb: ^^
12:31	ucb	clgv: nice. What was the issue?
12:31	danielglauser	david_pidcock: I haven't done a ton of webdev in Clojure but I don't think folks have found a web flow style necessary
12:31	clgv	ucb: the position of the type hint ^Callable led to the selection of the wrong submit method
12:32	danielglauser	david_pidcock: there are tons of ways to solve the web flow problem in Clojure
12:32	ucb	clgv: I see.
12:32	danielglauser	david_pidcock: And yes, I can see where that is a challenge for folks getting started
12:32	gtrak	david_pidcock: checked out pedestal yet?
12:33	david_pidcock	danielglauser: Yes - this was my gut instinct .. that the fundamental concepts of functional programming don't "project" on to web flow in the same conceptual way. I was wondering what the "functional" way of thinking about web flows and state might be…
12:33	gtrak	what's more flowy than event-sourcing?
12:33	david_pidcock	gtrak: I have not looked deeply into Pedastal. I found Luminus to be easier to get my brain around at this stage of my clojure-foo
12:34	danielglauser	gtrak: david_pidcock: The pedestal "base everything off of events" isn't a bad way to go.
12:34	david_pidcock	danielglauser: gtrak
12:35	danielglauser	david_pidcock: One approach with Ring/Compojure would be to store the intermediary state in a DB
12:35	danielglauser	david_pidcock: that has the added advantage of letting you serve requests via clustered Clojure servers
12:36	danielglauser	david_pidcock: removes the session replication problem
12:37	danielglauser	david_pidcock: I used to do a lot of work with Grails and this pattern is what I recommended that we do in Grails as well
12:38	david_pidcock	gtrak: danielglauser: I will look into Pedastel more closely. The scalability of storing state in db has it's limits too, as I've discovered in some of the massive scale projects I've worked on in java+mysql in the past. Spring Web Flow claims to get around them by serializing the flow state with each request.. (which has other issues)
12:38	david_pidcock	gtrak: danielglauser
12:39	danielglauser	david_pidcock: you could always keep the intermediary state in a distributed cache, something like Redis, <insert data store of the week here>
12:39	gtrak	so far in my dev life, I've always preferred solutions that let me pick and choose the tradeoffs myself, instead of a one-size fits all thing.
12:40	danielglauser	gtrak: inc
12:40	gtrak	I would be hesitant of any 'do something to everything' strategy
12:40	david_pidcock	danielglauser: gtrak: (lol this silly auto-complete I'm using for the names just sends a blank line for multiples ) Anyways --- I imagine that passing a map to and fro is actually very functional-friendly, come to think of it.
12:40	david_pidcock	gtrak : you have an excellent point
12:41	david_pidcock	(wherever that map might be held)
12:41	danielglauser	david_pidcock: in memory session state is an optimization, one I'm not convinced is any faster than an in memory store or cache
12:42	danielglauser	david_pidcock: what you have in an architecture problem and not a Clojure problem, just know that Clojure supports just about any architecture that you could come up with
12:43	david_pidcock	danielglauser: Well - I wouldn't call it a problem yet :D Just a question .. and one with many answers it seems. Thank you (and gtrak) for your insights.
12:44	danielglauser	david_pidcock: You're welcome. Best of luck!
12:45	n_b	Could someone suggest a good book on Java concurrency? I had a project this weekend where I felt having a better handling of the primitives underlying the Clojure system would've been a boon
12:45	gtrak	JCIP, then CTMCP
12:46	n_b	gtrak: the second one is by Van Roy?
12:46	gtrak	yea
12:46	SegFaultAX	n_b: Isn't the Java Concurrency book considered the de facto standard?
12:47	gtrak	JCIP was a bit unfulfilling in terms of design for me, I feel CTMCP will fill the gap. It was more about gotchas and primitive constructs.
12:47	n_b	SegFaultAX: I think so (it was recommended to nooglers last I checked), but I wasn't sure if anything had changed recently with Java7/8
12:47	amalloy	i've heard nothing but good things about JCIP
12:48	amalloy	i wonder if the office has a copy of it, actually. maybe i should read it
12:48	SegFaultAX	n_b: Definitely go with JCIP.
12:48	SegFaultAX	gtrak: In terms of design? What do you mean?
12:49	gtrak	SegFaultAX: I mean, I came into it with a mindset of 'I want to learn the design tradeoffs and how to build good concurrent systems from scratch', and it didn't really address stuff like that.
12:50	gtrak	it was more like... 'don't do these things... these are the guarantees provided by the java memory model, etc..'
12:50	SegFaultAX	gtrak: I don't really think it's supposed to be the former, is it?
12:50	gtrak	no, I guess not :-)
12:50	SegFaultAX	gtrak: I've never had that impression about it.
12:51	amalloy	right, you want more of a "concurrency in general" for that, not specifically java concurrency
12:51	gtrak	it never claimed to be I suppose, but that's what I was looking for and I couldn't tell at first glance that it wasn't it
12:51	amalloy	since the building blocks are mostly shared across languages
12:51	gtrak	CTMCP is more philosophical
12:51	n_b	Follow-up question: Is there anything Clojure-specific I should read? My problems were largely centred on properly balancing consumers and producers, actually handling failures of a part of the pipeline. Learning more about concurrency in general should be fine, I imagine, but input is, as always, welcome
12:52	SegFaultAX	n_b: Doubt it, since all of Clojure's concurrency primitives either wrap Java primitives, or literally ARE Java primitives.
12:52	dnolen	gtrak: hmm, I think Clojure's design reflects a fairly close reading of JCIP
12:53	SegFaultAX	Also, IIRC Hickey is a fan of JCIP and HFJ
12:53	gtrak	I could explain it another way, I already signed on to the principles of clojure and I didn't feel I learned a lot of new stuff from JCIP because of time spent studying clojure itself.
12:54	SegFaultAX	gtrak: I think you didn't have reasonable expectations for what JCIP would teach you.
12:55	gtrak	yea, I'm not saying don't read it, just that it doesn't address some things that I thought it might
12:55	gtrak	that other might think it would, too
12:55	gtrak	other people*
12:55	n_b	SegFaultAX: When I ended up diving into futures that aspect was very welcome. It was very "Oh, hey, I know this!". Agents and the way they pool took a bit more digging. But JCIP to start, thanks again!
12:56	SegFaultAX	n_b: You'll learn about thread pools and executors for sure. Agents aren't that much more once you have the basics.
12:57	SegFaultAX	Has anyone here looked at RxJava by Netflix? I watched a talk about it last night on InfoQ.
12:59	dnolen	gtrak: makes sense
12:59	noncom	S11001001: so ok, i have downloaded the 'automata' clojars group poms, and it has the poms with dependencies set correct.. how do i use them now to push it to my group with factual jars replaced?
12:59	n_b	SegFaultAX: Executors were very interesting to read about, it's been a great experience finding out just how little I know about both the Java stdlib and the JVM itself. Concurrency is fun stuff (until it's not)
13:00	ucb	clgv: forgot to ask: are you releasing your future+?
13:01	gtrak	SegFaultAX: what's HFJ?
13:01	SegFaultAX	n_b: I agree. I think one of the most eye opening experiences I had was when I was first trying to wrap my mind around Erlang's concurrency model. Really interesting stuff.
13:01	clgv	ucb: you can use the code from the gist. it's too small for a lib just yet
13:01	SegFaultAX	gtrak: Head First Java.
13:01	SegFaultAX	gtrak: One of the more popular intro to Java type books, I think.
13:01	ucb	clgv: cool, thanks :)
13:02	SegFaultAX	clgv: Have a link handy?
13:03	clgv	SegFaultAX: for the future+?
13:03	SegFaultAX	Yup
13:03	gtrak	I really like 'Effective Java'
13:03	gtrak	had a few epiphanies from that one
13:04	SegFaultAX	gtrak: Also an excellent book.
13:04	ucb	SegFaultAX: https://gist.github.com/guv/5445115
13:05	clgv	SegFaultAX: that's the one ^^
13:05	SegFaultAX	`fogus: Do you know yet if JoC 2 will be available in a Kindle format?
13:05	SegFaultAX	ucb: Thanks!
13:06	`fogus	SegFaultAX: Probably through Manning yes.
13:07	SegFaultAX	`fogus: Awesome! Looking forward to it. How much of an update is it over version 1?
13:15	`fogus	SegFaultAX: Most of the early chapters will be the same with some clarifications and new examples here and there. The latter chapters will be either new or quite different.
13:16	pl6306	Does edn support datetime? If so how do I represent one?
13:20	llasram	pl6306: #inst
13:22	llasram	&#inst "2013-04-23T13:21:00.000"
13:22	lazybot	⇒ #inst "2013-04-23T13:21:00.000-00:00"
13:22	technomancy	pl6306: be aware that #inst will result in a java.util.Date unless you fix it though
13:22	technomancy	see clj-time
13:22	tcrayford	does clj-time have tools for #inst now? I was fighting this the other day (ended up just serializing to json instead)
13:23	tcrayford	(in all honesty I didn't look all that hard)
13:23	pl6306	thanks!
13:23	technomancy	haven't used it myself, but pretty sure it's easy to hook up the parts
13:29	silasdavis	how can I join multiple ring routes together
13:29	SegFaultAX	Why does leiningen sometimes have double messages while fetching a dep? RetrievingRetrieving ns-tracker/ns-tracker/0.2.1/ns-tracker-0.2.1.jarring/ring-jetty-adapter/1.2.0-beta2/ring-jetty-adapter-1.2.0-beta2.jar fromfrom clojarsclojars
13:29	technomancy	SegFaultAX: concurrent IO is hard =)
13:29	silasdavis	say I have defroutes routes1 ..., defroutes routes2... I want to combine [routes1 routes2] into a single handler
13:30	technomancy	silasdavis: you can call routes2 from routes1
13:30	technomancy	it's just a function
13:30	amalloy	technomancy: yes, but he just wants (routes r1 r2)
13:31	technomancy	that too
13:31	technomancy	lots of ways to do it =)
13:31	technomancy	req is a map, routes1 and routes2 are functions; you do the math
13:31	amalloy	silasdavis: for educational purposes: (routes r1 r2) is equivalent to (fn [req] (or (r1 req) (r2 req))), and that's how defroutes works as well
13:32	technomancy	was trying to think of a point-free way to do it
13:32	SegFaultAX	Compojure uses `some` but yea.
13:32	amalloy	SegFaultAX: note i said "equivalent to"
13:32	technomancy	oh yeah; some
13:32	technomancy	duh
13:32	silasdavis	which `routes` function in `(routes r1 r2)`?
13:33	amalloy	it's in the same place as defroute, unsurprisingly
13:33	amalloy	defroutes is nothing but a macro that expands to (def ... (routes ...))
13:34	amalloy	technomancy: (comp first (partial remove nil?) (partial map (partial (flip deliver) req))), i think? if we're willing to pretend we have flip
13:35	technomancy	hah; nice
13:39	deg	I'm trying to deploy a small cljs project, built with lein-cljsbuild, so I did 'lein uberjar' and get an error on my one .cljs file: "aborting ... duplicate entry"
13:39	deg	Tried lein clean, and renaming the file, but the error persists.
13:42	silasdavis	amalloy, hm so will I need (apply routes r1 r2)?
13:42	silasdavis	since I don't know the number of GETS, POSTS etc in the macro
13:42	silasdavis	or no because that macro has already expanded
13:42	amalloy	there are no macros involved. r1 and r2 are both functions of one argument
13:42	antares_	ClojureWerkz now has its own irc channel: http://blog.clojurewerkz.org/blog/2013/04/23/irc-channel-for-clojurewerkz-project/ — feel free to join :)
13:43	silasdavis	In general if you have (macro1 (macro2 ...) ...) will macro2 have expanded by the time it acts as an argument to macro1
13:43	silasdavis	?
13:43	silasdavis	I suppose that's up to macro1
13:44	gtrak	silasdavis: macros expand recursively... if you don't have one with side-effects, why do you care when it happens?
13:44	silasdavis	it might be clear I haven't looked into macros in any depth yet...
13:45	SegFaultAX	silasdavis: What you're asking for has nothing to do with macros. r1 and r2 are simply functions. You can use the routes function from compojure to effective compose those routes.
13:46	silasdavis	SegFaultAX, I was thinking that they could be 'unexpanded macros' or something like that
13:46	gtrak	silasdavis: it happens top-first, ##(macroexpand-1 '(fn [] (let [blah 1])))
13:46	lazybot	⇒ (fn* ([] (let [blah 1])))
13:46	gtrak	let is also a macro
13:47	SegFaultAX	silasdavis: Macros are expanded at compile time. By the time (routes r1 r2) runs, all of that would have been expanded.
13:47	silasdavis	got it
13:56	n_b	Is there some Reader-like construct for sequences, i.e. traversable once, dropping items once accessed?
13:57	amalloy	n_b: how is that different from a sequence itself?
13:57	amalloy	i mean, what you've described is an iterator, but that's just a seq with gratuitous mutation
14:06	n_b	amalloy: It's a sequence, the problem is the way I've written this and at the moment having an iterator is much easier than fixing it. Not ideal, obviously
14:07	amalloy	shrug sequences implement Iterable, so you can make an iterator if you want
14:07	n_b	Ah, I see. Thank you.
14:08	jtoy	is there a way i can make a method that instead of calling this: (let [result (filter (fn[x] (= 1 (classify-scalar forest x))) (map (fn[x] (pop x)) examples) )] ....) can take an argument and call that in the the context of the map, so: (let [result (filter (fn[x] (= 1 (arg_to_call))) (map (fn[x] (pop x)) examples) )] ....)
14:09	S11001001	noncom: update the poms to have the proper groupid (yours) and version #s, and then...do something to deploy. I know the mvn deploy plugin can deploy a pom & jar pair in a single command, but there may be something easier to use.
14:09	n_b	amalloy: annnd your comment made me realise a way this can work with just a plain seq without changing anything. Much cleaner :)
14:11	S11001001	jtoy: aside, (fn [x] (pop x)) ≡ pop
14:16	jtoy	S11001001: I want to pass the arg into my filter
14:16	jtoy	i think I can do this, im having a mental blopc kthough
14:17	S11001001	jtoy: irrelevant
14:18	jtoy	S11001001: how do I call (classify-scalar forest x) if the arg I pass is 'classify-scalar forest) ?
14:19	jtoy	(classify-scalar forest) I mean and the x needs to be passed as a nn argument?
14:19	S11001001	jtoy: I've just been ignoring that part, in favor of pointing out that you can write (map (fn[x] (pop x)) examples) as (map pop examples)
14:20	jtoy	ok, i see what you mean, does that help with my problem?
14:20	jtoy	i see that that simplifies my code
14:20	S11001001	jtoy: insofar as you should see that `classify-scalar' might be found in the list of arguments to your function, yes
14:22	S11001001	jtoy: functions are ordinary values, and functions you make with defn are just as functiony as ones you make with `fn'
14:22	rasmusto	is there an idiomatic way to unroll {[:a :b :c] [1 2 3]} to {:a 1 :b 2 :c 3}? I know the [:a :b :c] key in advance.
14:22	S11001001	jtoy: including the functions in the standard library
14:23	jtoy	im still not exactly sure
14:23	amalloy	rasmusto: so it's a map with only one k/v pair in it?
14:24	rasmusto	amalloy: it could have other k/vs
14:24	amalloy	but you want to take one k/v pair out and do this to it?
14:24	rasmusto	amalloy: I'm thinking I might just do a zipmap whenever I find a vector as a key
14:25	rasmusto	amalloy: I'd like to dissoc [:a :b :c] from the map, and merge (zipmap [:a :b :c] [1 2 3]) with that map
14:26	rasmusto	amalloy: I think I have a solution bubbling up to the surface, I'll paste it in a sec
14:27	jtoy	S11001001: I think its something like this: (let [result (filter (= 1 arg_to_call ) (map pop examples) )] ....) but then Im not sure how filter passes the arg to arg_to_call
14:29	SegFaultAX	,((fn expand-key [m k] (let [v (m k)] (into (dissoc m k) (map vector k v)))) {[:a :b :c] [1 2 3]} [:a :b :c])
14:29	clojurebot	{:a 1, :b 2, :c 3}
14:30	SegFaultAX	rasmusto: ^
14:30	ToBeReplaced	heh, i'd have (apply zipmap (first (select-keys {[:a :b :c] [1 2 3]} [[:a :b :c]])))
14:31	ToBeReplaced	oh there's a merge misread, nvm me
14:31	S11001001	jtoy: arg-to-call is an arg you have yes?
14:32	rasmusto	SegFaultAX: that's beautiful. Thanks
14:32	SegFaultAX	rasmusto: Honestly I'm more curious why you have such a requirement.
14:33	rasmusto	SegFaultAX: parsing stdout strings from some crappy tool
14:33	SegFaultAX	rasmusto: Ugh, that sucks. Hopefully that's what you're looking for.
14:33	jtoy	S11001001: yes, the problem why I am not sure is because arg-to-call is (somemethod first-arg x_from_map), so I pass in(somemethod first-arg)
14:33	jtoy	and get ArityException Wrong number of args (1) passed to: core$classify-scalar clojure.lang.AFn.throwArity (AFn.java:437)
14:34	rasmusto	SegFaultAX: most definitely. I have it figured out now :)
14:34	llasram	jtoy: Are you trying to get to something like `(comp (partial = 1) (partial classify-scalar forest))`
14:34	llasram	?
14:35	jtoy	passing this in works: (fn[x] (classify-scalar @american_forest x)) is this the way I should pass my argument?
14:36	jtoy	llasram: I havent used partial, im studying it now
14:36	jtoy	hmm, thats cool
14:37	SegFaultAX	jtoy: ##((partial + 1) 1)
14:37	lazybot	⇒ 2
14:38	jtoy	cool, so I'll just pass partial then, seems easier then calling with a funcfn
14:40	amalloy	jtoy: your client keeps sending 0x7F (ascii DELETE) characters instead of actually backspacing over stuff before you send it
14:41	jtoy	amalloy: yeah, something seems broken, thx
14:42	Raynes	This is sad. I can't remember how to configure refheap.vim.
14:42	Raynes	The reason that is so sad is because I wrote it.
14:42	jtoy	haha
14:43	Raynes	Ah, there we go.
14:47	arrdem	am I reading this right? because algo.monads works using lazy sequences you can't use ^:dynamic vars "correctly" in monadic code.
14:48	technomancy	arrdem: you can't use dynamic vars anywhere laziness is used; correct
14:48	arrdem	bah ok thanks technomancy
14:48	technomancy	not strictly true, but trying to use them together is very error-prone
14:51	technomancy	if you can guarantee the laziness is consumed inside the scope of the binding it can work. but there are serious composability issues.
14:56	arrdem	yeah that's what I'm running into right now..
14:57	gfredericks	usually "don't use dynamic binding" is the preferred solution
14:57	technomancy	probably even more error-prone if the laziness is hidden behind monadic magic
14:57	technomancy	(the irony of a guy who goes by "technomancy" complaining about magic is not lost on me)
14:57	pl6306	Can I add meta data to an entry of map? Or is only possible add it to a map.
14:57	arrdem	pl6306: if the entry extends IObj yes you can
14:58	gfredericks	,(-> {1 2} first (with-meta {::a ::b}) (list) (->> (into {})) first meta)
14:58	arrdem	ok. guess I'm stuck with my global state atom then.
14:58	clojurebot	#<ClassCastException java.lang.ClassCastException: clojure.lang.MapEntry cannot be cast to clojure.lang.IObj>
14:58	amalloy	arrdem: wait, to the entry or the value?
14:59	arrdem	well gfredericks just torpedoed the entry.
14:59	arrdem	I was talking about the value
14:59	arrdem	(meta (:foo {:foo (with-meta :bar {:foo 3})}))
14:59	amalloy	gfredericks: that's lame. i would have expected c.l.MapEntry to be an IObj
14:59	deg	Re my question above (duplicate entry in uberjar of lein-cljs project) it looks like the problem is having multiple :builds, with a dash in one of the :output-to js files.
14:59	arrdem	,(meta (:foo {:foo (with-meta :bar {:foo 3})}))
14:59	clojurebot	#<ClassCastException java.lang.ClassCastException: clojure.lang.Keyword cannot be cast to clojure.lang.IObj>
14:59	gfredericks	amalloy: I thought it was a terribly fascinating question
14:59	arrdem	oh frick
14:59	technomancy	amalloy: if only we had inheritance amirite
14:59	deg	Did I violate a known rule, or should I report this as a bug?
15:00	gfredericks	since it's a vector, it oughta be an IObj. But since it's a map entry which isn't really first class, it'd be stupid to put metadata on it
15:00	amalloy	technomancy: hm?
15:00	arrdem	,(meta (:foo {:foo (with-meta [:bar] {:foo 3})}))
15:00	clojurebot	{:foo 3}
15:00	arrdem	ok yes so you can have metadata on vals in a map
15:00	technomancy	amalloy: just amusing that it looks like that problem is due to avoiding implementation inheritance
15:01	gfredericks	interfaces can inheret though, no? IPersistentVector could extend IObj?
15:01	amalloy	technomancy: really? clojure.lang doesn't make any effort at all to avoid implementation inheritance afaict
15:01	technomancy	amalloy: it's possible I don't actually know Java or anything about Java
15:01	amalloy	i think it's because c.l.MapEntry tries to be an optimized, special-purpose two-element vector and thus can't inherit any of the more general vector stuff
15:02	llasram	I thought keywords couldn't have metadata because they are explicitly singletons. You can't have different copies with different metadata
15:02	amalloy	llasram: indeed
15:02	technomancy	it would be like putting metadata on numbers
15:02	danneu	Question: I want to start 8 threads each with its own computation. Once any thread returns the answer, I want to clear out all the thread work and issue out 8 new computations. I've been reading about Java's Executors and Clojure's Agents, but could someone point me in the right direction?
15:02	llasram	Oh, I didn't scroll back far enough
15:02	technomancy	^:even 2
15:03	llasram	Heh
15:03	technomancy	^:prime 7
15:03	Glenjamin	can anyone recommend a validation library? i've done a quick survey but it's not obvious which one is actually used by people
15:03	technomancy	the Clojure Way is to write your own validation library
15:04	technomancy	everyone's doing it
15:04	arrdem	technomancy: no that's the Lisp Curse
15:04	Glenjamin	heh, certainly seems that way
15:04	callen	Glenjamin: validation for what? Web?
15:04	Glenjamin	in my case, yes - but maps in general should be fine
15:05	callen	Glenjamin: Okay, just use one of the existing libraries.
15:06	Glenjamin	mm, just trying to pick one that isn't abandonware
15:07	xeqi	Glenjamin: I've used weavejester's valip
15:07	Glenjamin	the one from weavejester looks good, but hasn't been touched for 2 years!
15:07	callen	maybe it's perfect!
15:07	callen	>_>
15:07	technomancy	for something that simple it's possible
15:08	TimMc	Glenjamin: clj-schema works well, although mind the lack of semver and changelogs.
15:09	danneu	prob spend more time looking for a lib than the moment it takes to roll your own every-pred
15:10	Glenjamin	meh, i hate rolling my own when existing options exist
15:11	Glenjamin	most of the stuff i've used for this project so far i've contributed back a fix/improvement for - everyone wins
15:11	danneu	Glenjamin: https://github.com/weavejester/valip/tree/master/src/valip
15:11	SegFaultAX	Glenjamin: Look at the source for valip
15:11	SegFaultAX	Glenjamin: It's like 10 lines of code.
15:12	technomancy	heh
15:12	Glenjamin	with tests, and other contributors
15:12	Glenjamin	if we all keep re-inventing the same simple wheels, we'd never build a decent car
15:12	SegFaultAX	There are a few obvious things you could do to improve it, but it doesn't do very much as it is.
15:12	gtrak_	what's even the measure of a good validation library?
15:12	xeqi	... does it validate
15:13	SegFaultAX	Also a shitload of pre-built validators.
15:13	technomancy	xeqi: I'm imaginging a "does it blend" style video series
15:13	gtrak_	the subset of all functions that take an arg and return a boolean?
15:13	danneu	libraries are useful when they save you time.
15:13	SegFaultAX	gtrak_: I'm thinking more like ActiveModel::Validations
15:14	SegFaultAX	gtrak_: I guess that's not a shit load per se, but it covers a large number of the common cases.
15:14	danneu	yeah, the value added clearly comes from the predicates, not the actual implementation
15:15	xeqi	technomancy: Yes, it validates!
15:15	SegFaultAX	One annoyance I have with valip is having to specificy the messages manually. That could be trivially moved into metadata with the option to override.
15:16	Glenjamin	i appear to have stumbled onto a hot button topic
15:16	SegFaultAX	Also, making composable validators is really handy. I often have a core set of validations that are shared across a number of different things.
15:17	jcromartie	I feel like using sets along with watches and validators is better than using hash maps to model collections
15:17	amalloy	a bit off-topic here: is there a handy equivalent to pmap in bash? i'd like to perform N independent tasks in parallel, and be notified when they're all finished. i don't want to bring the system to its knees by forking them all at once, though, so it would be nice if it ran on something like the pmap threadpool
15:17	jcromartie	amalloy: xargs
15:17	Raynes	lol
15:17	Raynes	amalloy just got told to xargs. That's a twist.
15:17	amalloy	jcromartie: wat. that is not even related
15:18	jcromartie	amalloy: no? how does xargs not do that?
15:18	SegFaultAX	amalloy: #bash can help.
15:18	Glenjamin	-P maxprocs Parallel mode: run at most maxprocs invocations of utility at once.
15:18	Glenjamin	^^ from man xargs
15:18	arrdem	wat
15:18	amalloy	interesting. i didn't know about that option. i guess it assumes each argument could be a separate call to proc
15:18	arrdem	well that's new...
15:19	Raynes	Wherein Glenjamin changes our lives.
15:19	SegFaultAX	(inc jcromartie)
15:19	lazybot	⇒ 4
15:19	jcromartie	xargs -P 8 -n 1 ...
15:19	Glenjamin	credit to jcromartie :)
15:19	jcromartie	yay
15:19	SegFaultAX	(inc Glenjamin)
15:19	lazybot	⇒ 2
15:20	xeqi	Glenjamin: have any interest in commit rights for peridot?
15:21	Glenjamin	xeqi: can do, nothing planned to add at the moment
15:21	Glenjamin	i'm building up some functions to use kerodon with speclj at the mo
15:21	xeqi	awesome, https://github.com/xeqi/kerodon/issues/8
15:23	Glenjamin	i've got a (should-have) function which behaves similarly to (has)
15:24	xeqi	added, nothing planned here either, but nice to have others that can do something if I get busy/miss a pr
15:25	Glenjamin	cheers
15:53	callen	Glenjamin: (should-have) is a very quaint way of saying (has).
15:54	Glenjamin	callen: in the context of speclj, all of it's test assertion methods start with (should)
15:55	callen	Glenjamin: sounds like communism.
16:07	arrdem	is there some trick I'm missing to make protocols use a default implementation over records? I'm being forced into replicationg the same code about 12 times 'cause I'm getting "no implementation" errors over my types if I don't.
16:08	Raynes	callen: I really like speclj's name. Except for the stupid fricken clj crap.
16:08	Raynes	I hope nobody ever creates a new project with a cutesy clj or jure name in front of me.
16:08	Raynes	For their safety cannot be guaranteed.
16:09	trptcolin	Raynes: juraynesic_parclj
16:09	n_b	Tell us how you really feel ;)
16:09	trptcolin	granted, it's a stretch
16:09	Raynes	n_b: How I really feel is illegal in all governed countries.
16:10	Glenjamin	could be worse, in ruby-land libraries tend to be named after common dictionary words which make them hard to google for
16:11	Raynes	There is a python lib called 'requests'.
16:11	Raynes	FFFFFFFFFFFFFFUUUUUUUUUUUUUUUUUUUUU
16:11	Glenjamin	heh, true
16:11	Chousuke	haskell libraries are even more fun
16:11	Chousuke	if you google for them, you get wikipedia pages full of maths
16:12	Raynes	I am guilty of using Haskell's name in vain in my libraries.
16:12	Raynes	$google haskheap
16:12	lazybot	[Raynes (Anthony Grimes) · GitHub] https://github.com/Raynes?tab=repositories
16:12	amalloy	what's wrong with 'requests'?
16:12	Raynes	amalloy: We were complaining about libraries that are common dictionary words.
16:12	amalloy	like...laser, tentacles...?
16:13	Raynes	I wasn't complaining, you'll kindly notice.
16:13	amalloy	you uh...shouted FU so loudly they heard you in arkansas
16:13	jjttjj	yeah i kinda like that googleibility is an aknowledged thing in clojure
16:13	Glenjamin	i could make a form handling lib, and call it "forms"
16:13	Chousuke	I don't really mind using common words for names, but then you should prefix it with clj or py or something
16:13	Raynes	amalloy: I was playing along with Glenjamin.
16:13	Raynes	Chousuke: Get off my IRC.
16:13	Chousuke	nothing wrong with a library called py-requests
16:13	Glenjamin	"clojure forms" is bound to be a fruitful search term
16:13	Raynes	clj-* names are equally as anger inducing.
16:14	Raynes	We need very strict laws governing library naming.
16:14	Chousuke	well, clj is not so good as a prefix
16:14	Glenjamin	you could pronounce it "kludge"
16:14	bbloom	i prefix all of my library names with me.raynes.bbloom.
16:14	Chousuke	since you can't even pronounce it
16:14	callen	Raynes: the requests library is really nice though.
16:14	Raynes	bbloom: <3
16:14	callen	Raynes: I love everything that guy does.
16:14	Raynes	callen: Yes it is. Ken is amazing.
16:14	stuartsierra	Group IDs are the way to go.
16:14	callen	Raynes: REITZ IS MAH HOMEBOY
16:14	jjttjj	after working with R for a bit i'd take the cheesy/generic names over things even more slightly harder to find on google
16:15	SegFaultAX	stuartsierra: Have you looked at RxJava?
16:15	stuartsierra	SegFaultAX: not yte
16:15	stuartsierra	*yet
16:15	Raynes	stuartsierra: You'll note that I've started naming reverse domaining all my libraries so as to not be lynched to death by an angry mob at my next conference appearance.
16:15	SegFaultAX	stuartsierra: There is a pretty good talk about it on InfoQ from the lead at Netflix.
16:15	bruceadams	and Ken Reitz is coming to talk at Pittsburgh Python's meetup tomorrow. anyone in Pittsburgh should come!
16:16	stuartsierra	Raynes: I don't lead lynch mobs. I just complain. ;)
16:16	SegFaultAX	stuartsierra: Observables are similar in a lot of ways to PromisesA it seems. Possible a substitute for a cljque-type lib.
16:16	Raynes	stuartsierra: Sure. That blue hair was merely a disguise.
16:17	bbloom	i'm with technomancy: short, reasonably unique by best effort google/github search, no ceremony
16:18	SegFaultAX	bbloom: Then you'll appreciate the new "unicorn" lib that's hot on HN right now.
16:18	SegFaultAX	Completely unrelated to all the other unicorn projects, but still uses the name and images associated with them.
16:18	bbloom	that's total fail at best effort search
16:18	callen	zero effort
16:18	callen	also, how can you possibly not know about unicorn (rack) and gunicorn (wsgi)?
16:19	callen	and still be working on an HTTP related thingi?
16:19	mpenet	stuartsierra: did you see dajac/react, it's another impl of promises/futures & co
16:19	SegFaultAX	Worse, it's indistinguishable from the unicorn web server.
16:19	SegFaultAX	Even the fricken logo is the same as the one GH uses.
16:19	bbloom	once past the best effort search, there is like a several week probation period where people can ask you to change the name
16:19	bbloom	past that, conflicts are not my problem
16:19	mpenet	stuartsierra: apparently it's used at paper.li
16:19	SegFaultAX	callen: They actually specifically address the name conflict on their site.
16:19	SegFaultAX	Something ot the effect of "we named it before it was written, and never changed it"
16:20	callen	...
16:20	callen	SegFaultAX: the author of using the excuse that his little sibling or something named it.
16:20	callen	is*
16:20	Glenjamin	i don't see a unicorn on HN...
16:20	stuartsierra	mpenet: no, haven't run into that
16:20	Glenjamin	aha, page 2
16:21	SegFaultAX	callen: Even so, they could have added something to it. unicornhttp or something, I don't know. And to use the angry unicorn. Wtf.
16:22	callen	SegFaultAX: they named the Ruby version "unicorn-rest" and the python one "unicorn" <--- lol
16:22	callen	SegFaultAX: not only do Python users love their gunicorn, but the Unicorn is the unofficial mascot of Django, so they're likely to get cranky.
16:23	mpenet	stuartsierra: have a look, he took another interesting approach, uses atoms under the hood, and seems to have a rich api around its futures
16:23	SegFaultAX	For those interested in RxJava: http://www.infoq.com/presentations/netflix-functional-rx
16:23	stuartsierra	mpenet: I haven't had any time to focus on promise for months.
16:24	callen	SegFaultAX: that looks a LOT like Twitter's Finagle
16:24	callen	SegFaultAX: same idea and use-case, implemented differently.
16:24	SegFaultAX	callen: RxJava?
16:24	callen	SegFaultAX: da comrade
16:25	technomancy	gun-i-corn
16:25	technomancy	is how I say it
16:25	SegFaultAX	callen: I haven't looked at Finagle, I'll take a look. RxJava in particular is a port of Rx.Net.
16:25	callen	technomancy: I say gew-nee-corn
16:25	SegFaultAX	technomancy: I say "goon-i-corn"
16:26	callen	SegFaultAX: well the idea behind Finagle was to have a generic framework for composable SOA with deliverables wrapped in promises in Scala
16:26	laliluna	lein midge causes: Caused by: java.lang.NullPointerException
16:26	laliluna	at java.util.concurrent.ConcurrentHashMap.hash(ConcurrentHashMap.java:332)
16:26	laliluna	at java.util.concurrent.ConcurrentHashMap.get(ConcurrentHashMap.java:987)
16:26	laliluna	at clojure.lang.Namespace.find(Namespace.java:188)
16:26	SegFaultAX	callen: From what I've read so far, RxJava is just a normal observer + an onComplete and onException callback.
16:26	callen	laliluna: midje?
16:27	SegFaultAX	callen: Otherwise they're identical to what you normally think of with Observers. And their interface is nearly identical to iterables.
16:27	laliluna	once cheshire.core is used
16:28	SegFaultAX	laliluna: Can you refheap the offending code and exception? It's hard to read in IRC.
16:29	jasonjckn	Does each var have it's own timeline in Rx?
16:29	jasonjckn	how do you get a consistent view
16:29	jasonjckn	in parallel environment
16:30	laliluna	https://www.refheap.com/paste/13903
16:30	callen	laliluna: first bit of advice, don't use midje.
16:31	SegFaultAX	callen: Aww, why? I like midje.
16:31	callen	SegFaultAX: I like things that work even more.
16:31	technomancy	because callen said so, obvs
16:31	technomancy	(actually I agree in this case)
16:31	Raynes	callen: Works for me in laser.
16:31	Raynes	shrug
16:32	Raynes	I switched it to midje before everyone decided that it is the worst thing ever.
16:32	SegFaultAX	callen, technomancy: clojure.test users?
16:32	TimMc	Minus the bizarre stack traces, it works fine.
16:32	SegFaultAX	TimMc: Clojure isn't known for awesome stack traces as it is. But generally yea.
16:32	technomancy	SegFaultAX: yeah; I find midje invents too many new concepts that don't offer provide enough value to justify not using similar built-in constructs
16:33	SegFaultAX	technomancy: Actually the only thing that drew me into midje was auto test in the repl. Is there something like that for clojure.test?
16:34	technomancy	if you have a small team on an internal project and everyone's on board that's one thing, but if you want contributors to your OSS project to bother with the tests, there's a very strong case to be made for the lingua franca.
16:34	technomancy	SegFaultAX: sure; clojure-test-mode
16:34	technomancy	trivial to wire into an after-save-hook in emacs
16:34	technomancy	SegFaultAX: that's actually another gripe of mine though
16:34	jasonjckn	SegFaultAX: https://github.com/stuartsierra/lazytest
16:34	SegFaultAX	technomancy: Oh is that an emacs thing? I'm a vim user.
16:34	technomancy	why would the auto-runner be coupled to the test framework
16:34	technomancy	that's just wrong
16:35	technomancy	write a watcher/auto-runner that operates on an arbitrary task; it's so obviously the right way to do it, but no one has actually done it =(
16:36	technomancy	(personally I haven't done it because I just use the elisp equivalent)
16:37	n_b	SegFaultAX: You should be able to just have a BufWrite aucmd for test files
16:37	SegFaultAX	Sure, or use guard to watch the files.
16:37	SegFaultAX	How does one reload the entire project without having to restart the repl? I'm not too familiar with the nrepl internals.
16:38	SegFaultAX	And by not too familiar, I mean at all.
16:38	Glenjamin	there's lots that are based on running an executable, but i think doing it within the jvm would be tricky to generalise?
16:38	technomancy	SegFaultAX: require with :reload-all
16:38	Glenjamin	or not
16:38	technomancy	Glenjamin: I don't think so. with :eval-in :nrepl you could easily do it without starting up a new JVM
16:38	Glenjamin	speclj's auto-runner is pretty nice, manages to figure out the dependency chain and only re-run affected tests
16:38	SegFaultAX	technomancy: That won't reload the project.clj file will it?
16:39	laliluna	By the way, any idea why it is failing once I require chesier?
16:39	technomancy	SegFaultAX: no, changes to project.clj require a fresh repl
16:39	technomancy	SegFaultAX: but that's already a given in the repl-based workflow
16:39	technomancy	so nothing really changes there
16:39	SegFaultAX	technomancy: Just curious.
16:40	laliluna	This is the way, I refer to cheesier: (ns foo.bar (:require [cheshire.core :refer :all]))
16:40	SegFaultAX	Heh cheesier.
16:41	llasram	Took me a minute to parse that :-)
16:41	laliluna	The irc client has type incorrection
16:42	TimMc	That's for sure.
16:46	Foxboron	So, every time i try eval a record in emacs-live, everything freeze.
16:46	Foxboron	s/record/protocol
16:56	nz	so what is actually wrong with midje (other than it is not standard like clojure.test)?
16:56	trptcolin	technomancy: unless i'm misunderstanding, that's what speclj does: https://github.com/slagyr/fresh
16:57	technomancy	trptcolin: ten points to griffindor!
16:57	technomancy	nice
16:58	technomancy	I think it could be done as a leiningen task too, but I haven't considered the trade-offs between the two approaches
16:58	TimMc	,(isa? 5 5)
16:58	clojurebot	true
16:58	trptcolin	it's pretty handy; we use it for the clojure koans as well
16:59	Raynes	nz: Well, admittedly it is a giant macrofest hack. But I'm fine with that for the most part.
16:59	trptcolin	[without actually using speclj]
16:59	TimMc	Has anyone seen Clojure's ad-hoc hierarchy system in use out in the wild? I'm curious what people use it for.
16:59	technomancy	trptcolin: will have to remember that for the next time someone says that's why they don't use clojure.test =)
17:00	technomancy	TimMc: the only one I know of that does that is friend
17:00	amalloy	TimMc: we use it a little at geni
17:01	amalloy	the web API exposes a bunch of endpoints like /bird/status, /horse/status, ..., and our dispatcher uses an isa? hierarchy that says those are all just special cases of /animal/status
17:01	technomancy	how long does it take before the "geni in a bottle" jokes get old?
17:03	TimMc	amalloy: Interesting. That uses a custom hierarchy, not the global one, right?
17:03	amalloy	nah, i think we just pollute the global hierarchy with keywords like :geni.api/bird or something
17:06	TimMc	,(isa? = 1 1)
17:06	clojurebot	true
17:06	TimMc	,(isa? = 1 2)
17:06	clojurebot	#<NullPointerException java.lang.NullPointerException>
17:06	TimMc	bah :-P
17:07	TimMc	I should have just left it at that.
17:07	technomancy	at least it didn't say true
17:08	SegFaultAX	Oh man, we just got a ping pong table in my office.
17:08	SegFaultAX	Goodbye productivity.
17:08	Foxboron	Trying again, having problems evaluating protocols in emacs-live, everything just freeze. Anyone able to point me int the right directions?
17:08	technomancy	Foxboron: the problem with emacs-live is it pulls in a bajillion different packages, so it's hard to tell which one is actually at fault
17:09	gtrak	SegFaultAX: happier devs means better code?
17:09	SegFaultAX	gtrak: That's the idea, I guess.
17:09	Foxboron	technomancy: i wasnt that succsessfull trying to setup Emacs on my own :/ Just feeling that this problem should have hit someone before, and not only me.
17:09	gtrak	I loved it when we had one, it made my life like 15% better
17:09	Apage43	Could be worse, we have a kegerator >.>
17:10	technomancy	Foxboron: you'd have to disable packages one by one till it quits breaking
17:10	technomancy	but IIRC emacs-live doesn't even use proper packages, so I don't even know how you'd do that
17:10	SegFaultAX	Apage43: Yelp had awesome kegerators.
17:11	Foxboron	technomancy: maybe i should just backup everything and do it the normal way :/ Annoying tho.
17:12	stuartsierra	jasonjckn, SegFaultAX: I gave up on auto-test-on-file-save after Lazytest. I think it's almost impossible for non-trivial apps. But that lead to tools.namespace and more work on reloading-from-the-REPL.
17:12	technomancy	Foxboron: I plan on writing a high-level guide covering various packages in the ecosystem and how they work together, but for now all I have is https://github.com/technomancy/better-defaults
17:12	SegFaultAX	stuartsierra: So what are you doing now?
17:12	technomancy	(note that this is not an emacs-live vs starter-kit thing; the starter kit has all the same problems)
17:13	Raynes	technomancy: Emacs live is super weird.
17:13	stuartsierra	SegFaultAX: Simulant.
17:13	technomancy	Raynes: well that too
17:13	SegFaultAX	stuartsierra: How does that work?
17:13	technomancy	I mean the "not using package.el" thing is specific to emacs-live and a really annoying problem
17:13	Foxboron	technomancy: i'll follow it closly. Thanks.
17:13	andrew__	Does anyone have experience using Java's ServerSocketChannel? I'm trying to make a simple server, but I can't seem to figure out how to set in to the proper thing to read any requests
17:14	stuartsierra	SegFaultAX: It's a totally different approach to testing. Not for everyone, but I like it.
17:14	Foxboron	Raynes: it is not that wierd...until you start messing with the whole package system. But out-of-the-box, it is OK for any beginner.
17:14	stuartsierra	https://github.com/datomic/simulant
17:14	SegFaultAX	stuartsierra: Are simulations different from unit tests?
17:14	Raynes	I don't like solutions that are bizarre when you stop being a beginner.
17:14	Raynes	I like things that just help you get going.
17:14	stuartsierra	SegFaultAX: very
17:15	hiredman	andrew__: serversocketchannel is an nio thing, which is java's async io framework, which is not what you want
17:15	technomancy	Raynes: that's why I want to switch gears to just documentation
17:15	stuartsierra	Simulation testing is a heavyweight approach to testing a whole system from the outside.
17:15	Raynes	technomancy: You're a good person.
17:15	Foxboron	I was just thinking btw. Are the dev.clojure.org site still in use? I wanted to add a few lines for the Sublime Text part as i got two packages for Clojure
17:15	technomancy	note that I haven't done it yet
17:15	hiredman	andrew__: serversocket has an accept method which blocks until a client connects, then returns a new socket you can get input and outpustreams from
17:15	stuartsierra	Foxboron: Yes, dev.clojure.org is still actively maintained.
17:16	Raynes	technomancy: You're a good person for wanting to do it.
17:16	andrew__	hiredman: I should've mentioned that, I'm trying not to use serversocket
17:16	hiredman	andrew__: clojure's in is for binding to streams
17:16	Foxboron	stuartsierra: you think anyone would mind if i add a few lines about my Clojure packages for ST2?
17:16	hiredman	clojure's reader reads from streams
17:16	stuartsierra	Foxboron: please do. There are "Getting Started" pages for each major editor / IDE.
17:16	SegFaultAX	stuartsierra: What do you like about it more than other more traditional styles of testing?
17:16	Foxboron	stuartsierra: i know, why i am asking ;)
17:17	hiredman	there are channel->stream adapters but you are biting off way more than you can chew
17:17	andrew__	hiredman: hmm, so it sounds like I'm trying to fit a square peg into a round hole
17:17	stuartsierra	SegFaultAX: Don't really have time to go into the details. Stuart Halloway has done some presentations on it.
17:17	SegFaultAX	stuartsierra: Ok I'll take a look. Thanks!
17:17	stuartsierra	np
17:21	Foxboron	stuartsierra: damn confusing site <.<
17:21	technomancy	Foxboron: clojure-doc.org has a lot better coverage of editor support
17:22	stuartsierra	Foxboron: dev.clojure.org suffers from serving multiple purposes: developer notes and user documentation.
17:22	stuartsierra	Also, Confluence. :(
17:22	Foxboron	stuartsierra: trying to see if i can edit the "Gettign started with Sublime Text"....nope..
17:23	Foxboron	technomancy: "a lot better", ST isnt even mentioned as i can see :P
17:23	stuartsierra	Foxboron: I believe the editing rights are given automatically to signers of the Clojure Contributor Agreement.
17:24	technomancy	Foxboron: a lot better for most topics; a lot easier to improve anyway
17:24	Foxboron	technomancy: i'll take a look at it tomorrow. Wanted to make a quick edit at dev.clojure.org...
17:24	Foxboron	wasnt that quick
17:25	TimMc	stuartsierra: My apologies for denigrating clojure/data.json yesterday. I was either working off of old information or thinking of a different lib entirely. :-'
17:25	TimMc	* :-/
17:26	andrew__	hiredman: by serversocket, did you mean the java ServerSocket class, or the server-socket library that used to be part of clojure.contrib?
17:26	stuartsierra	TimMc: Thanks you.
17:26	Foxboron	stuartsierra: i'll look into it. If anyone else can add them i got them on my github acc. Might be faster that way.
17:27	stuartsierra	TimMc: If I had a nickel for every ounce of grief I've gotten over that little JSON library, I could retire.
17:27	TimMc	That's like a metrix ton of grief.
17:28	TimMc	*metric, I shouldn't be allowed near keyboards today (or yesterday, apparently)
17:30	TimMc	stuartsierra: Oh, I'm curious; you have a private escape-unicode var -- is that intended to be public at some point?
17:30	TimMc	(I was checking for correct behavior around U+2028 and U+2029.)
17:31	stuartsierra	TimMc: No, control is all through key/value options on the public API functions.
17:33	TimMc	Oy, that's what I get for not reading docstrings.
17:33	stuartsierra	:)
17:35	TimMc	stuartsierra: Would you consider a patch to always escape U+2028 and U+2029? It eliminates a certain class of bugs: http://timelessrepo.com/json-isnt-a-javascript-subset
17:36	stuartsierra	TimMc: yes
17:36	TimMc	And I know your policy on that.
17:37	stuartsierra	Well, the Clojure contrib policies trump mine in this case.
17:38	TimMc	Yes, but IIRC, you also explicitly reserve the right to rewrite patches to your liking. :-)
17:38	stuartsierra	Indeed. :)
17:40	andrew__	hiredman: thanks for your input, I've played around with it a bit more and think you've set me down a much better path. Very much appreciated!
17:44	mynomoto	How do I call (meta) on a namespace?
17:46	stuartsierra	,(meta (the-ns 'clojure.core))
17:47	clojurebot	{:doc "Fundamental library of the Clojure language"}
17:47	Glenjamin	bah, why is there no with-err-str :(
17:47	mynomoto	stuartsierra: Thanks!
17:50	goza	hi, I'm trying to usecombinatorics on clojure 1.4, but I can't find the library as clojure.math.combinatorics or clojure.contrib.combinatorics. Anyone know where it went?
17:51	lzm	hfaafb: you will be missed
17:51	arrdem	goza: so clojure.contrib.* is dead.
17:51	arrdem	goza: https://github.com/clojure/math.combinatorics
17:52	goza	arrdem: yea, it's supposed to be under math.combinatorics now, but I can't find it
17:53	goza	arrdem: ClassNotFound for both clojure.math.combinatorics and math.combinatorics
17:53	Glenjamin	is it possible to with-redefs a java function?
17:59	goza	ah, I'm a total newb I guess. the libraries aren't like standard libraries. you have to download them because they're not built into clojure,
18:05	joegallo	Glenjamin: no. write a function that calls the function. always use that. that can be with-redef'd.
18:05	joegallo	s/that calls the function/that calls the method/
18:05	Glenjamin	yeah, just wrapped it - cheers
18:05	Glenjamin	i hate testing randomness =/
18:06	Glenjamin	UUID/randomUUID
18:06	joegallo	yeah
18:06	joegallo	(defn random-uuid [] ...) ; awww yeahhhh
18:06	Glenjamin	mm
18:08	arrdem	goza: yep, check out technomancy's tool "lein" for dealing with all that.
18:15	llasram	I've just started telling people that the Clojure command-line tool is spelled "lein," for historical reasons
18:16	technomancy	llasram: close; it's actually for hysterical reasons
18:16	llasram	heh
18:16	technomancy	not to be confused with hysterical raisins
18:18	callen	llasram: you don't tell them it's named after the story?
18:25	Glenjamin	I've decided to write a tcl interpreter in clojure...
18:26	Glenjamin	so i can name it tclj!
18:26	nightfly__	ticklojure
18:29	arrdem	Raynes: ^^
18:30	Raynes	arrdem: He's in DC, man. That's about as far away as you can get from me while still being in mainland USA.
18:31	arrdem	hum... so why does clojure.set not have a universal set..
18:31	bbloom	arrdem: the set of all objects including itself?
18:32	arrdem	bbloom: that's the one...
18:32	technomancy	(constantly true) <- that one?
18:32	arrdem	close enough.
18:32	hiredman	clojure.set is largely written in terms of seqs on sets
18:33	hiredman	clojure.set is only suitable for dealing with set datastructures, not math sets
18:35	arrdem	ok. I'm using a set of sequences of types as my function argument representation and was hoping for a non-hacky way to represent a function which will eat anything.
18:35	arrdem	looks like I'll just hack it tho.
18:53	pppaul	.set is nice
18:54	pppaul	functions don't eat
18:54	pppaul	they consume
19:17	aaelony	does anyone know the best place to ask incanter questions?
19:20	hiredman	try-let! let-try!
19:20	technomancy	there is no try. only do.
19:20	hiredman	,(try not do)
19:20	clojurebot	#<CompilerException java.lang.RuntimeException: Unable to resolve symbol: do in this context, compiling:(NO_SOURCE_PATH:0:0)>
19:20	hiredman	bah
19:21	technomancy	huh?
19:21	technomancy	shouldn't that be "couldn't take the value of a macro"?
19:21	hiredman	do isn't a macro
19:21	gfredericks	hiredman: it doesn't surprise me that you've probably written this before :)
19:21	hiredman	no, I try-let and let-try are just things I bring up at work from time to time
19:22	hiredman	given how often tryand let are combined
19:22	hiredman	like my with-with macro, which I think I actually implemented at one point
19:22	gfredericks	this is for having result-handling code alongside error-handling code
19:22	technomancy	ruby's def has an implicit begin (their version of try)
19:22	gfredericks	where the result-handling code's exceptions are _not_ caught
19:23	technomancy	sometimes I feel like that would make me more likely to bother catching exceptions
19:23	technomancy	if I didn't have to introduce another level of nesting to do it
19:23	hiredman	you would do (with-with [binding [...] with-connection connect] ...) and with-with would build (binding [...] (with-connection ..))
19:23	technomancy	you only need an explicit begin/rescue if you want to limit the scope of your handling to part of the function body
19:24	gfredericks	hiredman: one of the swiss arrows flattens out that pattern as well
19:42	pick	anymore familiar with monger?
19:43	pick	*anyone
19:44	pick	failing over here… clueless on this error when I try to connect with a db instance: NoSuchMethodError clojure.lang.RT.mapUniqueKeys([Ljava/lang/Object;)Lclojure/lang/IPersistentMap; monger.conversion/loading--4910--auto-- (conversion.clj:24)
19:45	amalloy	your program is AOT-compiled against clojure 1.5, but running on an older version, pick
19:45	gfredericks	hiredman: (if-try (compute) res (f1 res) Exception e (f2 e))
19:57	pick	amalloy: many thanks! sorting deps tree, blarg
20:00	Raynes	pick: lein clean
21:50	tieTYT	why am I getting this error: Exception in thread "AWT-EventQueue-0" clojure.lang.ArityException: Wrong number of args (1) passed to: core$eval10074$fn This is the code: (defmulti action-as-string (fn [action] (nth action 0))) (defmethod action-as-string :delete [[_ f] action]
21:50	tieTYT	(str "Deleting: " (.getAbsolutePath f)))
21:55	holo	tieTYT, maybe you need to have same arity both in defmulti and defmethod
21:55	tieTYT	hrm
21:56	tieTYT	i thought I did have that
21:56	tieTYT	oh right
21:56	holo	in defmethod I see 2 inputs
21:56	tieTYT	ok so how do you deconstruct a list?
21:57	holo	[_ f] if you mean this, I guess it's alright. what I mean is inputs of defmulti is 1, and defmethod is 2
21:59	holo	maybe you mean: (defmulti action-as-string (fn [[_ _] action] (nth action 0)))
22:00	tieTYT	you're right about my issue
22:00	tieTYT	but now I'm asking, how do you destructure a list?
22:03	holo	tieTYT. dunno. i usually just destructure vectors
22:03	tieTYT	yeah that's what I had to do
22:04	xeqi	&(let [[x y & more] (list 1 2 3 4 5 6)] {:x x :y y :more more})
22:04	lazybot	⇒ {:x 1, :y 2, :more (3 4 5 6)}
22:04	tieTYT	ah so you just treat it like a vector
22:05	tieTYT	I feel like destructuring is pretty hard in the "making simple easy" sense
22:05	tieTYT	maybe it's because the jay fielding article only demonstrates it in let bindings which adds another layer of complexity
22:08	holo	tieTYT, what's the difference if you do it in let or input params?
22:09	tieTYT	in a let, you need an even number of arguments
22:10	tieTYT	so when you're trying to learn the destructuring syntax, the let syntax obscures the signal by adding noise
22:12	holo	tieTYT, I think let is more explicit for learning this, cause you need something to destructure right? (list 1 2 3 4 5 6) is what you need, as shown in the example above
22:14	xeqi	well, you could write it ##((fn [[x y & more]] {:x x :y y :more more}) (list 1 2 3 4 5 6))
22:14	lazybot	⇒ {:x 1, :y 2, :more (3 4 5 6)}
22:14	tieTYT	holo: just create a function and call it instead
22:37	murtaza52	I have a seq '(2 3 1 4). I want to iterate through it, and whereever the previous element is smaller then the next element replace it with another seq '(- 4 1). So f('(2 3 1 4)) => (2 3 (- 4 1)). How do I write it?
22:43	amalloy	try (map list xs (rest xs)) and see if you can get anything interesting from that
22:49	murtaza52	amalloy : ah thats clever, really clever !
22:50	capcrunch	anyone uses clj-native ?
22:53	amalloy	~anyone
22:53	clojurebot	anyone is anybody
22:54	amalloy	clojurebot: forget anyone \|is\| anybody
22:54	clojurebot	I forgot that anyone is anybody
22:54	amalloy	~anyone
22:54	clojurebot	Just a heads up, you're more likely to get some help if you ask the question you really want the answer to, instead of "does anyone ..."
22:55	capcrunch	so nobody uses clj-native ?
22:57	amalloy	evidently nobody who uses it is so excited about it that they answer questions like "does anyone use it" within four minutes, at least
23:05	capcrunch	amalloy ...
23:07	Raynes	I sure bet the guy who wrote it uses it.
23:07	Raynes	Probably worth your chances emailing him or opening an issue on the github issue tracker or something.
23:10	capcrunch	Raynes , thanks ok , did you coded noir framework ?
23:13	xeqi	&(clojure.walk/postwalk #(if (vector? %) (remove nil? %) %) {:x [nil 1 2 3]})
23:13	lazybot	java.lang.ClassCastException: clojure.lang.Keyword cannot be cast to java.util.Map$Entry
23:14	xeqi	simplified example, but spot what I'm doing wrong?
23:14	xeqi	*anyone spot
23:15	technomancy	using clojure.walk, which has been repeatedly disowned by its author? =)
23:16	xeqi	heh
23:16	xeqi	I suppose that could be it
23:17	xeqi	was hoping for an easy way to transform a map with values of vectors of maps with vectors of maps ... :/
23:17	technomancy	IIRC clojure.walk was only included in clojure because clojure.test uses it
23:17	xeqi	lame
23:18	akhudek	I should really get around to releasing the zipper based visitor library I have.
23:18	xeqi	insert rage comic here
23:26	amalloy	xeqi: what about an orgy of into/for?
23:27	technomancy	postwalk implies to me that you don't know all that much about the structure of the input
23:28	xeqi	amalloy: I'm headed down a multimethod path that looks that direction
23:29	amalloy	heh. postwalk docstring addendum: "only intended for transformations that would be impossible in a statically-typed language"