2016-02-13
| 00:06 | gratimax | quick question about the REPL -- does it compile statements and expressions into bytecode before running them? and if so, how? |
| 00:09 | rhg135 | yes, and it has an emitter built in |
| 00:12 | gratimax | ok, hmm. looking at clojure.core/eval right now, and it seems like it delegates to an eval java method that looks like an interpreter |
| 00:16 | gratimax | ah, nevermind, ObjectExpr generates bytecode in a new class's init method for its eval method, quite cool |
| 00:21 | amalloy | gratimax: the eval method is rarely used; only in very simple repl expressions. most of the time, the relevant method is emit |
| 00:37 | gratimax | amalloy: ah, thanks |
| 00:49 | gratimax | amalloy: I couldn't find any usages for emit apart from static compilation, are you talking about clojure.core/repl? |
| 00:51 | amalloy | well, maybe i don't understand your context well enough and answered with something irrelevant |
| 00:51 | amalloy | what are you trying to learn about? |
| 00:52 | gratimax | mostly how the repl and runtime work |
| 00:54 | gratimax | I was wondering if you were talking about something different like nrepl |
| 00:59 | gratimax | oh, I think I see what you mean. for IFn, eval() delegates to emit() of the function calls within it |
| 01:00 | gratimax | err not IFn, FnExpr |
| 04:20 | benjyz1 | anyone know what to put as connection URI here for a H2 database? https://github.com/weavejester/ragtime/wiki/Getting-Started |
| 06:13 | kwladyka | How do you share between backend and frontend code like for example rules for validation https://github.com/leonardoborges/bouncer ? In separate module which you include to project.clj or another method? For example i have rules for register-step-1, register-step-2 etc. I want share this rules between all separated parts of the system. |
| 06:34 | eli | hello people |
| 06:34 | Guest7427 | so is anyone here |
| 06:45 | TEttinger | Redguy43: yes, a few hundred |
| 06:45 | TEttinger | it's the middle of the night for many of them |
| 06:46 | TEttinger | if you have a question, just ask and stick around until people wake up and get answering |
| 06:47 | Redguy43 | oh haha i live in belguim and i forget the timezone's sometimes |
| 09:26 | faxm0dem | Hi |
| 09:26 | faxm0dem | is there a simple way to replace a key's value in a map? |
| 09:31 | justin_smith | faxm0dem: depends what you mean - maps are immutable, but it's simple to make a new map with a replaced value for a specific key |
| 09:32 | justin_smith | ,(assoc {:a 0 :b 1} :b 2) |
| 09:32 | clojurebot | {:a 0, :b 2} |
| 09:32 | justin_smith | ,(update {:a 0 :b 1} :b inc) |
| 09:32 | clojurebot | {:a 0, :b 2} |
| 09:32 | justin_smith | ,(update-in {:a 0 :b [2]} [:b 0] inc) |
| 09:32 | clojurebot | {:a 0, :b [3]} |
| 09:32 | justin_smith | etc. |
| 09:33 | faxm0dem | assoc, of course |
| 09:33 | faxm0dem | justin_smith: thanks |
| 09:33 | faxm0dem | sorry, clojure.noob/here |
| 09:34 | justin_smith | np |
| 09:34 | justin_smith | just remember you have to use the return values of those functions |
| 09:34 | justin_smith | the original is unchanged |
| 09:34 | faxm0dem | sure thing |
| 09:34 | faxm0dem | immutable is beautiful |
| 09:57 | Malnormalulo | What exactly is the distinction between Sequential and ISeq? Why are those two different things? |
| 10:00 | kwladyka | i stack with jdbc error... https://www.refheap.com/114761 somebody see something what i dont see? |
| 10:01 | kwladyka | and of course id is uuid: id uuid PRIMARY KEY DEFAULT gen_random_uuid(), <- table construction is ok for sure |
| 10:02 | justin_smith | kwladyka: did you cat .getNextException on the BatchUpdateException object? |
| 10:02 | justin_smith | *call |
| 10:04 | kwladyka | oh i incidentaly find the problem... it is not about it.... it is about :status... it is enum field in DB |
| 10:06 | kwladyka | why can't use {:status "foo"} on enum field? |
| 10:23 | kwladyka | Are you using solution like that https://gist.github.com/rkneufeld/e5d1acbb007f47655508 or :stringtype "unspecified" to use JDBC with ENUM in PostgreSQL? Any disadventage of using :stringtype "unspecified" ? |
| 10:57 | timvisher | is there a db agnostic jdbc timeout that i can set? |
| 10:59 | timvisher | i'd like to set it for a specific `jdbc/query` |
| 11:04 | kwladyka | timvisher not sure if you can do it for one query, but you can always make second connection |
| 11:05 | timvisher | kwladyka: ah i should say that i have full control over the connection |
| 11:05 | timvisher | what i mean is is there something i can pass in the db spec that will cause statements executed on it to time out after, say, 100ms? |
| 11:06 | kwladyka | timvisher but i am not sure if db has option to set timeout only for one query, but there is an option to set timout for connection |
| 11:06 | timvisher | kwladyka: docs? |
| 11:07 | kwladyka | timvisher it depend on which DB you use |
| 11:08 | kwladyka | not from JDBC |
| 11:12 | timvisher | kwladyka: ah. that's not what i need then. i need it be entirely db agnostic |
| 11:13 | kwladyka | timvisher to work with every DB? I don't think so there is any ready solution |
| 11:13 | kwladyka | you should find out how to set it in every DB what you need and put all this solution in your code |
| 11:15 | kwladyka | I mean if you use Postgres you should do it in another way then you use MySQL |
| 11:15 | timvisher | kwladyka: sure. in reality i currently only need one. but that's far from ideal :P |
| 11:16 | kwladyka | timvisher for example in postgresql i see you can use that http://www.postgresql.org/message-id/BANLkTi=BKcBKAwqyqpDh2xWP9h3irQsVGg@mail.gmail.com <- maybe it is what you need |
| 11:16 | kwladyka | anyway i think you are doing something wrong if you need this for one query |
| 11:16 | kwladyka | i have to go... bye! |
| 12:08 | macrolicious | I'm wrestling with the following that's part of a tutorial: (defn even-numbers ([] (even-numbers 0)) ([N] (cons n (lazy-seq (even-numbers (+ n 2)))))) |
| 12:09 | macrolicious | calling (take 10 (even-numbers)) produces ; => (0 2 4 6 8 10 12 14 16 18) |
| 12:09 | macrolicious | is it fair to say that the recursive function takes a 'first pass' then a 'second pass'? If so, what is the state at each pass? |
| 12:10 | macrolicious | I'm confused by first expression of the defn. |
| 13:01 | spuz_ | hi i'm getting an error in my function saying "Don't know how to create ISeq from: java.lang.Long" what is the best way to debug this? |
| 13:02 | spuz_ | how can i find out the input to the function that is throwing the error/ |
| 13:02 | justin_smith | spuz_: it means you are calling a collection operation on a number |
| 13:02 | spuz_ | justin_smith, yeah i guessed that |
| 13:02 | spuz_ | i just don't know where that number is coming from |
| 13:02 | justin_smith | do you know which function is doing it? |
| 13:03 | spuz_ | well I typed *e at the repl and got the stack trace |
| 13:03 | spuz_ | from there i can see that it's a call to 'rest' |
| 13:03 | spuz_ | wondering what other tools i can use to figure out what is going on |
| 13:03 | spuz_ | i could println everywhere but that doesn't see correct |
| 13:04 | justin_smith | spuz_: if you want an actual debugger you'll probably have to use cursive |
| 13:04 | justin_smith | it's an editor plugin for idea |
| 13:05 | spuz_ | ok i'm using cursive |
| 13:05 | spuz_ | i'll lookup their docs |
| 13:05 | justin_smith | yeah, "degugging shoulnd't be hard to find", probably similar to any other degugging you would do in intellij idea |
| 13:05 | justin_smith | sorry for the random "" |
| 13:09 | spuz_ | justin_smith, ok it's pretty much what i'm used to |
| 13:10 | spuz_ | thanks |
| 13:31 | fantazo | what is the best practice of loading a file from resources? |
| 13:32 | amalloy | clojure.java.io/resource is usually involved |
| 13:34 | fantazo | amalloy, yep. but how? (load-string (slurp (clojure.java.io/resource "resource.clj"))) is not pretty. |
| 13:34 | justin_smith | fantazo: oh, so you want to load source code from a file? |
| 13:35 | amalloy | you want to eval a clojure source file? why is it in resources if it's source code? |
| 13:35 | justin_smith | in that case, just use require |
| 13:35 | justin_smith | file/resource/whatever |
| 13:35 | fantazo | justin_smith, well basically I want to load a edn but this is actually a clojure s-expression. |
| 13:36 | fantazo | I want to load a list of hashes I put into a file so that I can render that in a mustache file. |
| 13:36 | justin_smith | slurp and edn/read-string, or make a reader and use edn/read for successive entries |
| 13:36 | justin_smith | but really slurp and read string is easier and usually sufficient unless you have multiple top level forms |
| 13:37 | justin_smith | and all you need is a couple [] to turn multiple top level forms into one |
| 13:47 | fantazo | how do generally organize their compojure projects? |
| 13:49 | csd_ | amalloy: would you be able to speak to part of the 4clojure code? i have a question about a function in it, split-hosts |
| 13:50 | amalloy | sure |
| 13:51 | csd_ | so was the intent of that function to facilitate running the app on multiple servers, e.g. one for static content and another for dynamic content? |
| 13:51 | csd_ | i'm not clear on what exactly it is actually doing |
| 13:55 | amalloy | i never really planned to run it from multiple actual servers |
| 13:55 | amalloy | csd_: check out https://github.com/4clojure/4clojure/commit/4ef7b4e8, where it was added |
| 13:56 | csd_ | so its just an organization thing? |
| 13:57 | amalloy | i'm not sure really. it was five years ago and i rolled some of it back |
| 13:57 | csd_ | :) |
| 13:57 | amalloy | it might have been one of those "good practice" things |
| 13:57 | amalloy | to have your static resources on a different domain so you can use cloudflare or whatever |
| 13:57 | csd_ | ok thanks |
| 15:15 | rhg135 | do new threads inherit the Var bindings of the parent? |
| 15:23 | ashnur | why are there no datomic talk videos on youtube from the past year? one would think that there were many talks given on it.. |
| 15:25 | ridcully | there are at least to from end of 2015 from the conj(?) |
| 15:25 | ridcully | unless they got pulled |
| 15:26 | ashnur | maybe my search query was way too specific, will search again |
| 15:26 | ashnur | but still, strange, i searched for generate datomic queries |
| 16:02 | amalloy | rhg135: no, but if you use future to create the thread then it will |
| 16:03 | amalloy | ie, Thread. doesn't know about vars, but future does |
| 16:03 | rhg135 | ah that makes sense |
| 17:04 | macrolicious | I'm still a bit confused by (defn even-numbers ([] (even-numbers 0)) ([n] (cons n (lazy-seq (even-numbers (+ n 2))))))… is this an alternate syntax for aguments (i.e. if an argument is supplied, use those as [] but if not, call (even-numbers 0) ? |
| 17:06 | ridcully | yes |
| 17:07 | ridcully | imagine default params you might know from other languages |
| 17:07 | justin_smith | macrolicious: yes, that is the variable argument count syntax |
| 17:07 | justin_smith | (though of course it could do more than just provide default) |
| 17:18 | macrolicious | ok, understand now… found http://theburningmonk.com/2013/09/clojure-multi-arity-and-variadic-functions which discusses multi arity function definitions |
| 18:48 | amalloy | justin_smith: details re http://stackoverflow.com/a/35385598/625403 - creating a subvector is constant time, but each time you create a subvector or conj onto one, you add another "wrapper" over the underlying vector you started with, and your vector degrades into a linked list |
| 18:48 | justin_smith | amalloy: aha - I was talking about the constant time pop |
| 18:48 | justin_smith | but OK yeah |
| 18:48 | amalloy | but it's not even constant time to pop! |
| 18:48 | amalloy | is it? maybe it is |
| 18:49 | amalloy | i mean, it is, but you're just adding another wrapper |
| 18:49 | justin_smith | err sorry, not the pop, missspoke |
| 18:50 | justin_smith | aha, I should change my answer to persistentqueue |
| 18:50 | amalloy | conj and pop on a subvector are both constant time, but doing a lot of them makes peek *very* expensive |
| 18:50 | justin_smith | fascinating |
| 18:51 | amalloy | i bet it's not that hard to demonstrate, even. let's see |
| 18:52 | amalloy | ,((fn [v] (time (dotimes [_ 1e4] (peek v)))) (vec (range 1e3))) |
| 18:52 | clojurebot | "Elapsed time: 24.130148 msecs"\n |
| 18:54 | amalloy | ,((fn [v] (time (dotimes [_ 1e4] (peek v)))) (nth (iterate #(conj (subvec % 1 1e3) (first %)) (vec (range 1e3))) 1e3)) |
| 18:54 | clojurebot | "Elapsed time: 1.081422 msecs"\n |
| 18:54 | amalloy | ha. it said 100-odd ms when i /msg'd clojurebot with it first |
| 18:54 | amalloy | jvm warmup strikes again |
| 18:58 | arrdem | clearly we need a benchmarkbot |
| 18:58 | justin_smith | amalloy: edited that SO answer, thank you |
| 18:58 | justin_smith | critbot |
| 18:58 | arrdem | lazybot still dead |
| 18:59 | justin_smith | it amazes me we have a readable Exception literal now, but still no readable PersistentQueue literal |
| 18:59 | justin_smith | err, strike literal above, brain scrambled, shutting up now |
| 19:00 | arrdem | justin_smith: there are already patches for that lying around untouched since ~2013 iirc |
| 19:00 | justin_smith | arrdem: my laziness is vindicated! |
| 19:01 | arrdem | The tricky bit if I recall was implementing compilation for queue literals... |
| 19:01 | amalloy | good luck with that, justin_smith. it's been in the clojure-dev black hole for four years already |
| 19:01 | amalloy | https://groups.google.com/forum/#!topic/clojure-dev/GQqus5Wycno |
| 19:01 | arrdem | I'll merge one into clojarr :P |
| 19:01 | amalloy | is that your pirated version of clojure? |
| 19:02 | arrdem | hard fork yes, logo is forthcomming currently sketched as a pirate hook around a lambda |
| 19:02 | arrdem | https://github.com/arrdem/clojarr |
| 19:02 | ridcully | arrr! |
| 19:02 | arrdem | I need to write a changelog at some point... |
| 19:02 | justin_smith | arrdem: not a gnarly pirate with metal lambda for hand? |
| 19:03 | justin_smith | arr, keel-haul the prisoners under the hash-map matey |
| 19:03 | arrdem | I think Bronsa was proposing #[] for queue a while back.. |
| 19:03 | justin_smith | that totally makes sense |
| 19:04 | amalloy | so allow me to ask a couple leading questions about a queue literal. i do think it's a good idea, but it's probably trickier than you think |
| 19:04 | arrdem | I think that the merged pull request tab is pretty comprehensive, mod a bunch of noise around getting the repo set up and running. |
| 19:05 | amalloy | presuming that #[] is the queue literal: what does (peek #[(+ 1 1)]) return? |
| 19:05 | justin_smith | #[] |
| 19:05 | amalloy | peek, not pop |
| 19:06 | justin_smith | 2 |
| 19:06 | arrdem | IMO the reason to do #[] is that it puts queues syntactically on par with [], #{}, which evaluate their textual arguments. |
| 19:06 | amalloy | okay, so it evaluates its arguments. how about (peek #[(+ 1 1) (+ 2 2)])? |
| 19:06 | arrdem | eager same as the others |
| 19:07 | justin_smith | amalloy: 4 |
| 19:07 | amalloy | really? i would expect the one on the left to be the one in the pop position |
| 19:07 | arrdem | yeah pop is leftmost |
| 19:08 | arrdem | sorry peek/pop |
| 19:08 | arrdem | same as vector |
| 19:08 | amalloy | so already there's some confusion, that's exciting |
| 19:08 | amalloy | vectors pop on the right |
| 19:08 | arrdem | I rememberd that right after hitting enter point amalloy |
| 19:08 | justin_smith | amalloy: there's some artificial confusion on my end |
| 19:08 | amalloy | haha |
| 19:08 | amalloy | clojurebot: alcohol is artificial confusion |
| 19:08 | clojurebot | In Ordnung |
| 19:09 | ridcully | artificial? |
| 19:09 | justin_smith | ridcully: weed (it's legal here) |
| 19:09 | arrdem | amalloy: I believe that the existing printers for lists eg as provided in CIDER, fipp show head on the left, tail right. |
| 19:09 | ridcully | ye lucky sob |
| 19:09 | arrdem | Eg. print in seq order |
| 19:09 | arrdem | read/print being nominally an isomorphism... |
| 19:09 | amalloy | sure, and i agree that's the order that makes the most sense. but that's one point that's not totally obvious |
| 19:10 | arrdem | I mean.. it is obvious you just have to declare vector Silly |
| 19:10 | amalloy | next up: what does this print? #[(println "Hello, ") (println "world!")] |
| 19:11 | amalloy | actually i guess that's not as confusing as i thought. i was thinking this would naturally lead to evaluating things in backwards order, but it doesn't |
| 19:11 | arrdem | yeah if you push on the end, you evaluate left to right with no problems |
| 19:12 | justin_smith | amalloy: hell you could even use natural eval order matching conj order as your first criteria in determining print order |
| 19:12 | arrdem | gives you the same result as [(println "foo") (println "bar")] already does |
| 19:12 | amalloy | yeah, i guess i'm out of leading questions |
| 19:12 | arrdem | That Wasn't Hard (tm) |
| 19:12 | amalloy | the question of whether it evals its arguments or not is the main one, since #queue [(+ 1 1)] shouldn't |
| 19:13 | amalloy | but #[(+ 1 1)] should |
| 19:13 | arrdem | right, which is why I said #[] |
| 19:13 | arrdem | I agree it's Hard otherwise |
| 19:14 | justin_smith | wait, am I missing something abvious? why shouldn't #queue [] eval its args? |
| 19:14 | arrdem | justin_smith: because it "looks the same" as a user defined reader literal which by convention shouldn't eval |
| 19:15 | amalloy | reader literals all don't eval |
| 19:15 | arrdem | not that I haven't written reader literals that eval... |
| 19:15 | justin_smith | arrdem: shows how much I know about user defined literals, thanks |
| 19:16 | amalloy | likewise #foo.MyRec[...] doens't eval |
| 19:17 | hiredman | I wonder if rich doesn't add a literal because pqueue has it is currently implemented has issues with complexity analysis and amortization |
| 19:17 | arrdem | https://github.com/arrdem/meajure I think this does reader literal eval |
| 19:17 | justin_smith | I guess I'd know that if I ever used them other than as a side effect of dumping to edn |
| 19:17 | hiredman | as |
| 19:17 | hiredman | the cost of the flip isn't properly amortized because of the lack of laziness |
| 19:18 | hiredman | oh, of course the first comment |
| 19:18 | hiredman | " so no reversing or suspensions required for persistent use" |
| 19:19 | amalloy | that's a reason i hadn't considered before |
| 19:21 | amalloy | but right, vectors mean you don't need to amortize |
| 19:23 | ridcully | alcohol? |
| 19:23 | clojurebot | alcohol is artificial confusion |
| 19:24 | ridcully | well done |
| 19:24 | j-pb | balmer peak? |
| 19:24 | ridcully | thats how it works |
| 19:24 | ridcully | or the bot is confused |
| 19:46 | csd_ | is slamhound / its emacs plugin still maintained |
| 19:46 | csd_ | or rather, does it still work with the latest versions of cider et al |
| 19:47 | amalloy | i would be astonished if it did |
| 19:47 | csd_ | is there an alternative |
| 19:47 | arrdem | refactor-nrepl |
| 19:50 | ridcully | vim ^_^ |
| 19:51 | csd_ | arrdem: unless i'm mistaken though, that won't add things for you automatically, right? it still requires a degree of user manipulation. i've never really used it but that's what it appears like to me |
| 19:52 | csd_ | eg i still have to navigate to a symbol and tell it to add to the ns |
| 19:56 | amalloy | slamhound never really worked great anyway |
| 19:56 | amalloy | the reason we have ns declarations at all is that you can't just take a symbol and unambiguously guess what namespace it's from |
| 20:00 | rhg135 | technically speaking on some you can. fully qualified symbols |
| 20:00 | justin_smith | rhg135: what if I intended to do (require [clojure.string :as clojure.core.async] |
| 20:00 | justin_smith | I mean that would be daft, but it's legal |
| 20:01 | rhg135 | that.. is just.. nice |
| 20:01 | ridcully | legal in your county |
| 20:01 | csd_ | ha |
| 20:01 | justin_smith | ,(require '[clojure.string :as clojure.core.async]) |
| 20:01 | justin_smith | ridcully: lol |
| 20:01 | clojurebot | nil |
| 20:02 | justin_smith | ,(clojure.core.async/join ">" ["a" "b" "c" "d"]) |
| 20:02 | clojurebot | "a>b>c>d" |
| 20:02 | futuro | good lord |
| 20:03 | justin_smith | I'm not saying it's a good idea, just saying it's possible |
| 20:03 | amalloy | reasons not to make weed legal: justin_smith's weird pedantry |
| 20:03 | clojurebot | No entiendo |
| 20:04 | justin_smith | amalloy: I had a free pass there, the point I was correcting was already pedantic |
| 20:04 | amalloy | true fact |
| 20:43 | kenrestivo | i found slamhound very useful for cleaning up ns forms that had accumulated cruft |
| 20:44 | kenrestivo | i.e. import and require a ton of stuff in ns A, then refactor it out into ns B C and D, then ns A has tons of crap it doesn't need anymore |
| 20:45 | kenrestivo | only problem is slamhoud choked on #'foo.bar/baz and some other things |
| 20:45 | kenrestivo | as i recall |
| 20:46 | kenrestivo | also if you're fetishistic and you want your ns alphabetized but don't want to waste time doing it by hand, it does that |
| 20:46 | kenrestivo | aand, confirmed, it works with clojure 1.8, just used it a month ago |
| 20:48 | ridcully | you are a vim user |
| 20:49 | justin_smith | "yer a vimmer harry" |
| 20:50 | justin_smith | is there a spoof of harry potter where the sorting hat gives you an editor? |
| 20:50 | justin_smith | calling it now, vim=slytherin |
| 20:56 | timvisher | what am i missing about clojure.java.jdbc/with-db-connection? it appears that `prepare-statement` is a way to set a timeout on a query via the `:timeout` option. _but_ it also appears to need a Connection object, which I thought `with-db-connection` would have given it, but printing the class of the bound var in the body of `with-db-connection` yields a map, not a connection object |
| 20:56 | timvisher | but reading the source of with-db-connection _really_ leads me to believe it should be a Connection |
| 20:56 | justin_smith | timvisher it's an object that it knows how to turn into an actual connection |
| 20:57 | justin_smith | timvisher: it can contain an actual connection, a connection pool with a method to get a connection, or credentials with which to connect |
| 20:57 | justin_smith | all should work |
| 20:57 | justin_smith | being a clojure wrapper, it likes to get a hash map with various magic keys |
| 20:58 | justin_smith | timvisher: for example when I upgraded a project to use a pool, I didn't change the connection object I was already using, I used the credentials and connection info it already contained to generate a pool, and put that into the same map with the credentials |
| 20:58 | justin_smith | none of the other code was changed at all and it just worked |
| 20:58 | clojurebot | Pardon? |
| 21:00 | timvisher | justin_smith: are we talking about the same thing? i.e. i think you're talking about the db-spec in `(with-db-connection [conn db-spec] …)` when i'm talking about the `conn` in `(with-db-connection [conn db-spec] (println (class conn)))` |
| 21:00 | justin_smith | timvisher: one moment, double checking |
| 21:00 | timvisher | at least the source of with-db-connection _looks_ like it takes the dbspec and turns it into a real connection with `get-connection` and `add-connection` |
| 21:02 | justin_smith | timvisher: it is a binding form, OK, I was confusing with-connection and with-db-connection |
| 21:02 | timvisher | or maybe it's that i don't understand what add-connection does |
| 21:02 | timvisher | right. with-connection is deprecated |
| 21:02 | justin_smith | timvisher: so it takes (with-db-connection [conn-db db-spec] and in that scope conn-db will be a connection created using that spec |
| 21:03 | justin_smith | timvisher: so conn-db is the explicit connection used (replacing the implicit connection with-connection imposed) |
| 21:04 | timvisher | so if i understand what you're saying correctly i'm not sre why `(with-db-connection [conn {:blah :blah}] (println (class conn)))` prints `clojure.lang.PersistentArrayMap` |
| 21:04 | timvisher | s/sre/sure/ |
| 21:04 | justin_smith | it's in impl detail of clojure.java.jdbc I'd bet |
| 21:04 | justin_smith | and it has a key describing the open transaction, that will be used when it's passed as an arg |
| 21:05 | timvisher | yeah. which means i'm going to have to go through all sorts of faffery to get a real connection :( |
| 21:05 | justin_smith | timvisher: ahh, you need the conn object directly? for interop calls to java.jdbc or what? |
| 21:06 | timvisher | well it seems that `prepare-statement` needs an _actual_ java.sql.Connection |
| 21:06 | timvisher | not just a db-spec |
| 21:06 | timvisher | which sucks because it appears to be the only way to `setQueryTimeout` |
| 21:07 | justin_smith | that's a hell of a yak you got there, nice |
| 21:07 | timvisher | and just more generally i'm confused at what with-db-connection is actually doing |
| 21:07 | timvisher | perhaps if the 'db-spec' is a java.sql.Connection (maybe in the context of a pool?) then it will pass that through |
| 21:08 | timvisher | but with the db-spec map it seems to just be doing nothing |
| 21:08 | timvisher | ah… maybe it's adding metadata |
| 21:08 | timvisher | nope |
| 21:09 | timvisher | sheesh you'd think this would be an option on `query` |
| 21:09 | timvisher | that'd be too obvious though |
| 21:19 | timvisher | ok so the solution is to just use `(with-open [conn (jdbc/get-connection db-spec)] …)` it would seem |
| 21:19 | timvisher | ¯\_(ツ)_/¯ |
| 21:19 | justin_smith | congrats! |
| 21:20 | rhg135 | ,((comp meta meta) (with-meta 'a {:suchmeta true} {})) |
| 21:20 | clojurebot | #error {\n :cause "Wrong number of args (3) passed to: core/with-meta--4375"\n :via\n [{:type clojure.lang.ArityException\n :message "Wrong number of args (3) passed to: core/with-meta--4375"\n :at [clojure.lang.AFn throwArity "AFn.java" 429]}]\n :trace\n [[clojure.lang.AFn throwArity "AFn.java" 429]\n [clojure.lang.AFn invoke "AFn.java" 40]\n [sandbox$eval25 invokeStatic "NO_SOURCE_FILE" 0]... |
| 21:21 | rhg135 | ,((comp meta meta) (with-meta 'a ^{:metameta true} {})) |
| 21:21 | clojurebot | {:metameta true} |
| 21:21 | rhg135 | Cool |
| 21:22 | ridcully | it could be a db connectiomn |
| 21:22 | justin_smith | rhg135: you could do a meta / with-meta version of the weird thing I showed sdegutis the other day with assoc / get |
| 21:23 | rhg135 | What thing, justin_smith |
| 21:23 | justin_smith | rhg135: one minute, recreating |
| 21:24 | timvisher | ridcully: was that for me? |
| 21:24 | justin_smith | ,(take 10 (reductions :rocks (iterate (fn [x] {:rocks x}) :rocks)) |
| 21:24 | clojurebot | #<RuntimeException java.lang.RuntimeException: EOF while reading> |
| 21:25 | justin_smith | ,(take 10 (reductions :rocks (iterate (fn [x] {:rocks x}) :rocks))) |
| 21:25 | clojurebot | (:rocks {:rocks :rocks} :rocks {:rocks {:rocks {:rocks :rocks}}} {:rocks {:rocks :rocks}} ...) |
| 21:25 | rhg135 | I like that you can put data about data about data |
| 21:25 | justin_smith | rhg135: the pattern of the result is that every power of 2 item is :rocks |
| 21:25 | ridcully | timvisher: no |
| 21:26 | rhg135 | justin_smith, wow |
| 21:26 | justin_smith | the one after it has next power of 2 instances of :rocks in its tree, nextp2-1, nextp2-2 etc. until next power of two is :rocks again |
| 21:26 | justin_smith | rhg135: I am thinking this pattern/phenomenon must have a known name, it's cool |
| 21:27 | justin_smith | this is probably an oddly specific version of a much more general and elegant phenomenon |
| 21:29 | justin_smith | rhg135: pprinting in your own repl and taking like 32 items helps |
| 21:30 | rhg135 | I'll remember to do that when I'm at a computer |
| 21:30 | justin_smith | w(n) is 1 if n is a power of 2, otherwise it is (h - (n-l)) where h is the next highest power of 2, and l is the next lowest |
| 21:31 | rhg135 | I don't think my car can run clojure... |
| 21:35 | justin_smith | I solved it! :rocks will remove an outer layer of the hash map at each step, until :rocks is not found |
| 21:36 | malwarez | =] |
| 21:36 | justin_smith | then it will take the nth deep nesting (n incrementing for each layer it had removed) |
| 21:37 | justin_smith | so it jumps to 1 for every power of 2, then goes to the next pow of 2, then counts down to 1 again |
| 21:42 | justin_smith | rhg135: I made it a gist https://gist.github.com/noisesmith/9b331f0f7a87b644ce10 |
| 21:43 | justin_smith | that gist also exposes the "breakpoints" in the pprint algorithm in an interesting way |
| 21:44 | rhg135 | That last line... |
| 21:45 | justin_smith | rhg135: anyway, I thought maybe you could do something similar with attaching and removing meta, until I realized it was exploiting the behavior of three-arg get |
| 21:47 | rhg135 | Yeah I see that now. At first I thought the function you passed to reductions was unary |
| 21:47 | justin_smith | right, that would not have worked at all |
| 21:49 | rhg135 | Yeah, hence my confusion |
| 21:53 | amalloy | justin_smith: the most unnecessarily complicated way i've ever seen to draw ascii hockey sticks |
| 21:54 | justin_smith | amalloy: haha, thanks |
| 21:54 | justin_smith | amalloy: the pattern is fascinating, and was an amusing 30 minutes or so of mental effort to puzzle out and solve |
| 21:56 | rhg135 | What fun is there in being straightforward |
| 22:11 | csd_ | clojuredocs.org is down |
| 22:12 | rhg135 | Works for me |
| 22:12 | csd_ | must be dns issues on my end |
| 22:15 | csd_ | nope, google's dns has no record... |
| 22:28 | matthavener | csd_: doesnt resolve for me |
| 22:48 | irctc922 | if i have an "env" vector. how can i add another key/val to it? (assoc) doesn't seem to persist |
| 22:51 | csd_ | an env vector? |
| 22:51 | irctc922 | a vector named env that stores various environment variables |
| 22:51 | irctc922 | sorry new to this |
| 22:52 | csd_ | is it a map? maps store key value pairs, a vector is more like an array |
| 22:52 | irctc922 | a map then |
| 22:52 | irctc922 | ah, sorry used the wrong temr |
| 22:52 | csd_ | assoc would add to a map but it returns a new map rather than mutating the old one |
| 22:52 | irctc922 | ah, so what can i do in this case |
| 22:52 | irctc922 | how would i mutate the map |
| 22:53 | csd_ | well in most cases you wouldnt as immutability is one of the paradigms of clojure |
| 22:54 | csd_ | if you really need to there are mutable types available, such as atoms which might be what you are looking for |
| 22:54 | csd_ | but clojure does require rethinking how you're used to programming if you're new to that sort of paradigm |
| 23:06 | rhg135 | ,(assoc [] 0 1) |
| 23:06 | clojurebot | [1] |
| 23:07 | TEttinger | ,(assoc [] 1 2) |
| 23:07 | clojurebot | #error {\n :cause nil\n :via\n [{:type java.lang.IndexOutOfBoundsException\n :message nil\n :at [clojure.lang.PersistentVector assocN "PersistentVector.java" 188]}]\n :trace\n [[clojure.lang.PersistentVector assocN "PersistentVector.java" 188]\n [clojure.lang.PersistentVector assocN "PersistentVector.java" 22]\n [clojure.lang.APersistentVector assoc "APersistentVector.java" 343]\n [clojure.... |
| 23:07 | TEttinger | aw |
| 23:07 | rhg135 | Interesting. I didn't think it did non existing indices |
| 23:07 | csd_ | is it possible to rename the function i'm :refer'ing |
| 23:08 | TEttinger | well, it does _a_ non-existing index |
| 23:08 | csd_ | [foo :refer [bar :as baz]] |
| 23:08 | TEttinger | the one equal to length |
| 23:08 | rhg135 | On vectors, but it does match the map behavior |
| 23:08 | rhg135 | ,(doc refer) |
| 23:08 | clojurebot | "([ns-sym & filters]); refers to all public vars of ns, subject to filters. filters can include at most one each of: :exclude list-of-symbols :only list-of-symbols :rename map-of-fromsymbol-tosymbol For each public interned var in the namespace named by the symbol, adds a mapping from the name of the var to the var to the current namespace. Throws an exception if name is already mapped to somethin... |
| 23:09 | csd_ | im guessing its not possible |
| 23:09 | rhg135 | Eh, but yes csd_ |
| 23:10 | rhg135 | :renames iirc |
| 23:10 | csd_ | ahh |
| 23:10 | csd_ | sorta annoying the inconsistent syntax |
| 23:10 | rhg135 | But it might make people hate you |
| 23:10 | csd_ | :as was giving me an error |
| 23:11 | csd_ | :rename isnt working either :/ |
| 23:11 | justin_smith | TEttinger: did you see the fun generator / output I posted above? |
| 23:12 | csd_ | oh nm |
| 23:12 | amalloy | csd_: (require my.ns :rename {bar baz} :refer [baz]) ;; or maybe refer bar, i forget |
| 23:14 | csd_ | eh, in any event it won't let me do what i was trying to do, which is take import function foo, rename it foo* and then create wrapper function foo which calls foo* |
| 23:14 | TEttinger | justin_smith: nope |
| 23:14 | TEttinger | just got here |
| 23:15 | justin_smith | OK, check out this function/result before scrolling up to my explanation https://gist.github.com/noisesmith/9b331f0f7a87b644ce10 |
| 23:16 | justin_smith | it generates a series of larger/smaller hash maps in cycles |
| 23:25 | hodwik | Does anyone have any idea why, while going through the Clojrue Brave chap 1 tutorials, I'm getting a Java error |
| 23:25 | hodwik | At the Emacs section |
| 23:26 | hodwik | "CompilerException java.land.RuntimeException: unable to resolve symbol: -main in this context, compiling [...]" |
| 23:28 | justin_smith | hodwik: what are you trying to run when you get that error? |
| 23:30 | hodwik | (ns clojure-test.core (:gen-class)) (defn -man "Test" [& args] (println "testing!")) |
| 23:31 | hodwik | http://www.braveclojure.com/basic-emacs/#A_Cornucopia_of_Useful_Key_Bindings |
| 23:31 | justin_smith | hodwik: I think you want that -man to be -main |
| 23:32 | hodwik | Yeah, it's a main, I didn't copy pasta |
| 23:33 | justin_smith | was your cursor right on -main when you ran C-xC-e ? |
| 23:33 | justin_smith | because it is supposed to be at the end of the file for that demo |
| 23:34 | justin_smith | "eval last defun" is very sensitive to where your cursor is at |
| 23:35 | hodwik | Shoot, it works now. My cursor is in the same place. |
| 23:36 | hodwik | Chance for edification wasted |
| 23:36 | hodwik | Thanks for your help though justin_smith |
| 23:36 | justin_smith | C-M-x on the other hand loads the whole expression the cursor is in |
| 23:36 | hodwik | I was doing C-c M-n |
| 23:36 | hodwik | and then |
| 23:37 | hodwik | (-main) |
| 23:37 | hodwik | from a repl |
| 23:37 | justin_smith | and well you didn't mention you ran (-main), and that would indicate a completely different source of your problem, yes |
| 23:37 | justin_smith | clearly you hadn't loaded that definition into the right scope yet |
| 23:38 | hodwik | That's the weird thing |
| 23:38 | hodwik | the repl showed my app |
| 23:38 | hodwik | as the thing> |
| 23:38 | justin_smith | if there is an error in your function definition, the ns is still loaded |
| 23:39 | justin_smith | but that function (and the ones after it) are simply unavailable |
| 23:40 | hodwik | The function definition stayed static |
| 23:41 | hodwik | does it matter if started the repl with M-x cider-jack-in |
| 23:41 | hodwik | vs |
| 23:41 | hodwik | M-x clojure-main M-x cider-main C-c M-j |
| 23:41 | hodwik | er **mode, not main |
| 23:42 | justin_smith | you can use M-x describe-key to find out what C-c M-j does |
| 23:42 | hodwik | Yeah, C-c M-j runs cider-jack-in |
| 23:43 | hodwik | hmm |
| 23:52 | hodwik | @justin_smith now it's doing something else weird |
| 23:52 | hodwik | http://i.imgur.com/ssndSUP.png |
| 23:52 | hodwik | Haven't changed anything as far as I can tell, just restarted emacs and went to same point |
| 23:52 | hodwik | Any idea what this is? |
| 23:52 | hodwik | "Namespace not found." |
| 23:55 | hodwik | Anyone have any idea what I'm doing wrong? |
