2012-01-01
| 05:02 | lypanov | hey, is there a way to set a variable like this "(def *vm-session-type* "headless") from another file? |
| 05:03 | lypanov | i imagine its basic clojure knowledge. but i don't have time to finish my joy of clojure and need to get something working today ;) |
| 09:39 | Somelauw | Happy new year |
| 09:40 | Somelauw | I wanted to write a pokerhand recognizer in clojure. This is the code I ended up with for recognizing a full house: http://pastebin.com/q0Z5xBYK. What do you think of it? |
| 10:22 | wingie | how can i know what a function do in the repl and what args it takes? |
| 10:24 | gko | (doc function) |
| 10:24 | clojurebot | Titim gan éirí ort. |
| 10:24 | gko | ,(doc print) |
| 10:24 | clojurebot | "([& more]); Prints the object(s) to the output stream that is the current value of *out*. print and println produce output for human consumption." |
| 10:25 | wingie | gko: thanks |
| 10:25 | wingie | (doc function) |
| 10:25 | clojurebot | Excuse me? |
| 10:25 | wingie | (doc print) |
| 10:25 | clojurebot | "([& more]); Prints the object(s) to the output stream that is the current value of *out*. print and println produce output for human consumption." |
| 10:26 | wingie | (prn 1) |
| 10:26 | wingie | :) |
| 10:31 | ordnungswidrig | hi allo. |
| 10:45 | djh__ | has anyone ever used clj-http |
| 10:45 | djh__ | I'm struggling to get my head around one thing |
| 10:46 | djh__ | I'm trying to login to a website |
| 10:46 | djh__ | using POST |
| 10:46 | djh__ | I can login with my credentials which returns a cookie |
| 10:46 | djh__ | but I don't know how to "put" that cookie into subsequent requests |
| 11:05 | wingie | why isn't another delimiter used to create a list instead of having it like this: (list 4 3 2 1) |
| 11:06 | wingie | {} and [] are not used using a macro .. so why did they made a decicion that list should also be for execute the first one as function/macro ? |
| 11:07 | Chousuke | (foo bar) already is a list. it just evaluates as a function call. |
| 11:07 | Chousuke | [foo bar] is a vector, aand vectors have different evaluation rules. |
| 11:08 | Chousuke | you need to either quote the list (to prevent evaluation) or construct the list dynamically via a function call. |
| 11:09 | wingie | Chousuke: I see |
| 11:09 | wingie | could you say that a vector is like an array in other langs? |
| 11:12 | Chousuke | ,(let [foo {:bar 'test} bar :bar] ['[foo bar] '(foo bar) [foo bar] (foo bar)]) ; like this |
| 11:12 | clojurebot | [[foo bar] (foo bar) [{:bar test} :bar] test] |
| 11:12 | xcv | wingie: The underlying data structure is quite different, in order to preserve performance guarantees while staying immutable, but apart from the immutable properties, it feels a lot like a python/ruby array |
| 11:13 | Chousuke | I'm in a train and this internet connection is really laggy :P |
| 11:13 | Chousuke | took me a minute to write that example. |
| 11:14 | Chousuke | ssh is not the most pleasant tool to use with a connection that has 500ms average lag. |
| 11:15 | wingie | :) |
| 11:15 | wingie | xcv: right |
| 11:17 | Chousuke | anyway, the important thing to understand is that (foo bar) is a list, you just can't use them "as is" like vectors because a list is an operator call in clojure. |
| 11:18 | kzar | I want to import [org.apache.commons.lang RandomStringUtils] but I'm not having much luck, do I need to add something to project.clj? (I'm not really clear how you figure that out for Java libraries.) |
| 11:18 | Chousuke | in most cases where you'd want a literal list a vector will do just fine anyway |
| 11:19 | Chousuke | it's very rare to see actual calls to list in clojure code (it's more common in other lisps because they don't have vectors with useful evaluation semantics like clojure's) |
| 11:19 | xcv | wingie: As to the question of why lists are evaluated like they are, that comes back to lisp code being represented as lists: the function call reader interpretation for the list (list-as-code) is assumed to be more common than the list-as-data interpretation, so it gets the simpler syntax of the two. |
| 11:21 | xcv | wingie: Lists are basically singly-linked lists, with most of their performance characteristics (linear lookup etc) while arrays behave pretty much like you'd expect arrays to. |
| 11:21 | Chousuke | rather, it's impossible to have lists be function call forms while evaluating to themselves at the same time. |
| 11:21 | xcv | haha! Yep, that would definitely be tricky :P |
| 11:22 | Chousuke | if you have some other syntax for function calls that still somehow used lists, Clojure would lose its homoiconicity. |
| 11:22 | Chousuke | of course, you could have vectors be the function calls but then you'd just have the same problem with vectors instead of lists :P |
| 11:53 | solussd | is using a defn inside of a let good form? I have a bunch of functions that all need to reference the same "global", but I'd rather not put a 'def' at the namespace level |
| 11:53 | solussd | e.g. (let [something "some value"] (defn* ….) |
| 11:58 | Somelauw | I wanted to write a pokerhand recognizer in clojure. This is the code I ended up with for recognizing a full house: http://pastebin.com/q0Z5xBYK. The double transformation to a hashmap annoys me a little. |
| 12:00 | weavejester | The fullhouse function seems a little heavy for what its doing |
| 12:00 | Somelauw | Heavy? |
| 12:00 | Somelauw | Can it be done simpler? |
| 12:00 | weavejester | Well, if you just wanted to check if someone had a full house, then... |
| 12:00 | Somelauw | Oh, but I also want to return the fullhouse. |
| 12:00 | weavejester | (and (contains-pair? hand) (contains-three? hand)) |
| 12:01 | weavejester | Ah, presumably the highest fullhouse too? |
| 12:01 | Somelauw | Since I want to compare which fullhouse is best. |
| 12:01 | Somelauw | Yes, the highest |
| 12:01 | weavejester | I'd probably split it up into two problems then... |
| 12:02 | weavejester | (defn fullhouse? [hand] (and (pair? hand) (three? hand))) |
| 12:02 | Somelauw | And a implicit precondition is that there are no quads in the input of fullhouse. |
| 12:02 | weavejester | (defn highest-fullhouse [hand] (if (fullhouse? hand) (concat (highest-pair hand) (highest-three hand)))) |
| 12:02 | Somelauw | But if there are 3A's and 3J's, a fullhouse can be made by taking only 2 jacks. |
| 12:04 | weavejester | Hm... yes, a 3A 2J beats a 3J 2A |
| 12:04 | weavejester | So... |
| 12:05 | weavejester | Maybe something to take the cards |
| 12:05 | Somelauw | But a hypothetic highest-pair function will either ignore the 3J's or return the aces. |
| 12:05 | weavejester | Yes, you'd have to use partitioning |
| 12:07 | weavejester | Really you want a form of state... |
| 12:09 | Somelauw | The input could consist of 7 cards: 5 on the table and 2 held. |
| 12:09 | weavejester | Hold'em, presumably? |
| 12:09 | Somelauw | yes |
| 12:11 | Somelauw | state? why? |
| 12:13 | weavejester | Well, you'd want to ensure that the pair and three are different, but perhaps there's a better way to do that. |
| 12:15 | weavejester | It almost feels like a combinations function would be good here. |
| 12:16 | weavejester | Maybe your function is the best way of doing it. Let me take a look... |
| 12:17 | Somelauw | You mean trying all permutations of 5 cards? That would probably be slower but work as well. |
| 12:22 | weavejester | Hm... It makes sense to have a (pairs hand) which returns all the valid pairs, and a (threes hand) which returns all valid three of a kinds |
| 12:23 | bsteuber | Somelauw, weavejester: I'd do it like this: https://gist.github.com/1547828 |
| 12:23 | weavejester | So then the question becomes, do this pair and three overlap or not? |
| 12:23 | Somelauw | If I make three-of-a-kind return all remainders as well in a map, I could run pair on the remainders. |
| 12:23 | Somelauw | bsteuber: I'll take a look |
| 12:24 | weavejester | bsteuber: Does that account for the case where you have overlaps, e.g. 3J 3A ? |
| 12:26 | Somelauw | pair would return the highest triple or pair and do (take 2 on the output). |
| 12:26 | carlos1 | hello! |
| 12:26 | weavejester | bsteuber: Yeah, it looks like it might cover all cases |
| 12:26 | weavejester | carlos1: hello! |
| 12:28 | carlos1 | where can I have a good explanation of "when"? |
| 12:29 | weavejester | I'd be tempted to write a function (defn independent? [xs ys] (empty? (set/intersection (set xs) (set ys)))) |
| 12:29 | Somelauw | carlos1: (doc when)? |
| 12:30 | weavejester | carlos1: It's like "if" but all the forms after the condition execute in sequence |
| 12:30 | weavejester | carlos1: So... (when true (println "Hello") (println "World")) would print "Hello" then "World" |
| 12:30 | carlos1 | weavejester, but in (when true 1 2 3), only 3 seems to be executed |
| 12:31 | ordnungswidrig | carlos1: only 3 is returned. |
| 12:31 | weavejester | carlos1: All are evaluated, but only the last evaluated form is returned from an expression |
| 12:31 | carlos1 | ha ok. now everything makes sense. thank you |
| 12:31 | weavejester | (when x y z) is equivalent to (if x (do x y)) |
| 12:32 | ordnungswidrig | carlos1: the REPL can be confusing in this regard. compare (print 1) vs. 1 |
| 12:32 | carlos1 | it's OK haha |
| 12:33 | carlos1 | I understand. just a simple way of make an imperative if |
| 12:40 | weavejester | Somelauw: Maybe something like https://gist.github.com/1547883 |
| 12:41 | weavejester | Though I'm not sure if the order of the full-houses is correct... |
| 12:43 | weavejester | Maybe the order should only be calulated at the end with a (sort-by (comp sum rank)) |
| 12:46 | Somelauw | I came up with: http://pastebin.com/8dE8Bw49 |
| 12:46 | Somelauw | weavejester: I'll take a look |
| 12:48 | weavejester | Just added an overall-rank function for sorting |
| 12:48 | Somelauw | bsteuber: Thanks for your idea |
| 12:56 | Somelauw | I'm not sure but when determining the overall rank of a fullhouse, I thought first the triples are compared and then the pairs. |
| 12:57 | yoklov | if i wanted a fifo queue in clojure… can I get that? or should i just write my own |
| 12:57 | Somelauw | Thanks for helping me |
| 12:57 | Somelauw | afk |
| 12:58 | tscheibl | yokov: clojure.lang.PersistentQueue |
| 12:58 | tscheibl | yokov: you must create an empty one using PersistentQueue/EMPTY |
| 12:58 | yoklov | Oh, alright, huh. |
| 13:01 | tscheibl | yokov: look here: http://fiji.sc/javadoc/clojure/lang/PersistentQueue.html ... for some reason they still haven't wrapped it in idiomatic clojure but it's there and I've been using it for some time now |
| 13:01 | tscheibl | yokov: howeer, after creation you can use it like any other collection |
| 13:01 | tscheibl | however.. |
| 13:02 | yoklov | hm? |
| 13:04 | tscheibl | yoklov: you can use "peek" to get the most recent element you added with "conj" and use "pop" to get a new collection with this element removed |
| 13:05 | yoklov | oh okay, right, no mutation, pop would have to return a new queue |
| 13:05 | yoklov | instead of just the top value |
| 13:06 | tscheibl | yep |
| 13:06 | tscheibl | it's an immutable persistent collection like the others |
| 13:06 | yoklov | you know, coming from scheme i thought that wouldn't trip me up as much as it has. |
| 13:08 | tscheibl | maybe that's the reason why it's still "not officially" in clojure... it feels somewhat awkward |
| 13:09 | yoklov | haha, maybe. I sorta meant in general though. |
| 13:10 | yoklov | but yeah, queues are inherently imperative so it sorta makes sense that it would be a weird thing. |
| 13:10 | tscheibl | yoklov: you could also try lamina from ztellman (u find it on github).. it provides a somewhat statefull "channels" based abstraction.. |
| 13:11 | yoklov | hm. strange. |
| 13:13 | yoklov | I'm not really looking for more state, to be honest. I think of my scheme (racket) code as typically being fairly stateless but when programming in clojure I tend to realize "oh yeah i'd usually use a set! here" |
| 13:16 | yoklov | Oh, you mean for a queue |
| 13:16 | tscheibl | use atoms in these cases... or alter-var-root if you want to change the root binding of vars that don't get changed very often |
| 13:16 | tscheibl | ..instead of set! :) |
| 13:17 | tscheibl | yoklov: yeah u could use lamina channels like queues |
| 13:17 | yoklov | Oh, it's not a queue of things which need to be done, it's representing some data that when it changes it adds to the front and removes from the end. |
| 13:18 | yoklov | so i think persistent queue is more of what i want. |
| 13:18 | tscheibl | probably |
| 13:18 | tscheibl | channels are propably to "heavy weight" for that purpose |
| 13:18 | yoklov | Right |
| 13:21 | yoklov | so atoms are for when a thing needs to change? what are vars for then? |
| 13:21 | tscheibl | .. too ... damn keyboard :p |
| 13:26 | Vinzent | hm, I don't know it too - what's exactly the difference between swap!-ing the atom and altering-var-root? |
| 13:26 | tscheibl | yoklov: changing the root binding of a var generally isn't a very idiomatic practice |
| 13:27 | tscheibl | i beleive alter-var-root is primarily accomplished using locks (although I haven't looked at the code) yet |
| 13:28 | tscheibl | atoms use STM which should be better for performance |
| 13:28 | yoklov | oh okay, i thought there was another way of changing a var for some reason. |
| 13:28 | tscheibl | ..and you can use atoms everywhere... just bind it to any symbol.. locally scoped or dynamically |
| 13:29 | carlos1 | "user=> (new FileReader "source.txt")' opposed with this syntax sugar "user=> (FileReader. "source.txt")" is there any reason for the usage of that shortcut? |
| 13:29 | Vinzent | tscheibl, yeah I also think it's locks, but I'm not sure... Also, strictly speaking, atoms don't use STM, only refs do |
| 13:29 | Vinzent | carlos1, second is idiomatic |
| 13:30 | AWizzArd | Hello technomancy, please have a look into your query windows, thanks :-) |
| 13:30 | carlos1 | Vinzent, I would expect that, but I cannot seem to familiarize or find any reason for the decision, which makes it counter intuitive for myself |
| 13:30 | tscheibl | Vinzent: why wouldn't they? they have the same semantics as refs? |
| 13:31 | tscheibl | they just automatically commit |
| 13:31 | yoklov | So, sorry about all the questions, but what's the relationship between refs and atoms? |
| 13:31 | yoklov | is there any? |
| 13:31 | tscheibl | isn't it? |
| 13:32 | tscheibl | yoklov: you can change multiple refs in one transaction and commit them atomically |
| 13:32 | yoklov | Right, and you can't do that with atoms? |
| 13:33 | tscheibl | atoms just allow you to change their value atomically |
| 13:33 | yoklov | alright. |
| 13:33 | Vinzent | carlos1, well, it's 3 chars shorter! :) I don't know the details behind this decision, but I'm used to it very quickly |
| 13:34 | Vinzent | tscheibl, I thought STM refers to dosync and transactions, that's why it is software transactional memory :) |
| 13:35 | carlos1 | Vinzent. maybe because dot at the end means instantiation, as opposed to dot in the middle which means namespace escalation |
| 13:35 | yoklov | Its really interesting how well integrated concurrency is into clojure. I'm getting into it not for that but because it's a more modern lisp that runs on the jvm which seems quite well thought out, but it's very cool that it has all of these language-level concurrency semantics. |
| 13:35 | Vinzent | tscheibl, and if they just automatically commit, then why the perfomance is higher with atoms? |
| 13:35 | Vinzent | tscheibl, but actually I don't know, maybe you right |
| 13:36 | tscheibl | Vinzent: hmm.. you may be right... |
| 13:36 | tscheibl | Vinzent: but they have the "retry" semantics in common with refs |
| 13:37 | tscheibl | Vinzent: although they obviously don't use STM in the background |
| 13:38 | tscheibl | actually I've still never really found a reason to use refs in my projects... |
| 13:39 | tscheibl | .. atoms always did the job |
| 13:39 | yoklov | are refs the one that maintain a history? |
| 13:41 | Vinzent | tscheibl, yeah, the same for me. I guess I just haven't faced such problems |
| 13:43 | tscheibl | yoklov: changing refs within a dosync creates a local copy of the changed refs and only commits the changes if not one of them was changed in the meantime.. otherwise the transaction retries |
| 13:44 | tscheibl | ... it's the same with an atom.. just you don't do it in a dosync |
| 13:44 | yoklov | Oh hm, so thats what the ref-history-* functions mean? |
| 13:45 | tscheibl | .. so you can't change multiple atoms synchronously |
| 14:05 | Somelauw | Hm, does clojure sort lazily? |
| 14:08 | AWizzArd | Somelauw: https://github.com/clojure/clojure/blob/master/src/clj/clojure/core.clj#L2679 |
| 14:08 | AWizzArd | The sort fn forwards sorting to some eager JVM methods. |
| 14:09 | AWizzArd | So, sort is not lazy. |
| 14:14 | Somelauw | AWizzArd: okay, thanks |
| 14:37 | graphbum | howdy..i'm trying to abstact some stuff (a graph library) into a protocol but i hit a roadblock. is anyone willing to hear me out? |
| 14:38 | Raynes | ~anyone |
| 14:38 | 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 ..." |
| 14:39 | yoklov | is it more idiomatic clojure to use defstruct for a simple data structure to just use a map? |
| 14:40 | Vinzent | defstruct is kinda deprecated in favor of defrecord |
| 14:40 | Raynes | It is never idiomatic Clojure to use defstruct. It was generally replaced by records in 1.2. Furthermore, you almost always just want a map. |
| 14:40 | yoklov | i see |
| 14:40 | yoklov | thank you |
| 14:40 | Raynes | "Is there any reason for me to use defrecord?" is a good question to ask. |
| 14:40 | Raynes | Yourself, I mean. |
| 14:41 | Raynes | If the answer isn't technical, then you probably want a map. |
| 14:43 | AWizzArd | In most cases I want a record. A map is interesting if I want to hold tons of key/value pairs. |
| 14:43 | AWizzArd | Also records are able to hold any number, like maps. It is only that their access is a few nanoseconds slower. |
| 14:44 | Raynes | Why create a type for the sake of creating a type? |
| 14:44 | yoklov | what benefits does it hold? |
| 14:45 | AWizzArd | It depends on the situation. If you have a function which just wants to return some data, and it makes sense to return it in a key/value fashion, then a map is perfect. |
| 14:45 | graphbum | how can a protocol be modified, or properly utilized, account for different constructors? For instance, most operations on immutable structures can be represented as returning "new" structures via some base constructor function. I want to separate the underlying data storage mechanisms for a graph from the abstract operations on a graph (the graph protocol), so that I can create effecient implementations for various graph stru |
| 14:45 | AWizzArd | A record is interesting if you want to have a typed map, and when you know the keys already. |
| 14:45 | AWizzArd | Records should hold the core data of your application. |
| 14:46 | graphbum | protocols dispatch on the type of the first arg, so defining something like (make-graph [g nodes arcs]) inside the protocol doesn't quite work, since g might be implemented as a record (currently), but might be an array later |
| 14:47 | Vinzent | graphbum, you can use kind of factory or multimethods |
| 14:47 | graphbum | is there a significant performance penalty associated with multimethods that non-extended protocols avoid? |
| 14:47 | AWizzArd | yoklov: also records can be used in combination with Protocols. |
| 14:47 | Raynes | yoklov: Here is an excellent flow chart that will help you decide what to use. https://github.com/cemerick/clojure-type-selection-flowchart/raw/master/choosingtypeforms.png |
| 14:48 | Raynes | yoklov: I'd mostly just focus on what it says. |
| 14:48 | yoklov | haha, alright: regular map |
| 14:49 | Vinzent | graphbum, yeah they are slower, but does it really matters in your case? |
| 14:51 | graphbum | I have strayed away from using multimethods for high-traffic or performance sensitive calls, so I cannot answer that definitively at the moment |
| 14:53 | graphbum | I've tried sticking with protocols defined inline with defrecords as needed, for both inherent performance and for defining consistent operations |
| 14:55 | graphbum | are there any benchmarks on the performance hits for using multimethods? maybe something similar to Rich Hickey's transients vs. vectors benchmarks? |
| 14:58 | yoklov | graphbum: err, i'm not really a clojure programmer but that sounds a lot like premature optimization to me. |
| 14:58 | Vinzent | graphbum, I don't know about benchmarks, but you can use factory protocols like this https://gist.github.com/1548186 if you doubt |
| 15:00 | graphbum | vinzent, thanks. you're swtiching to reificiation to avoid the problem then. that's useful. |
| 15:00 | Vinzent | np |
| 15:03 | graphbum | yoklov: it's not premature...there are cases, particularly in graph algos, where arrays are ideal. to me, it makes sense to be able to change the underlying representation as neeeded to exploit effeciencies. I'd like to deal with everything as a lazy sequences, but that only goes so far. |
| 15:03 | yoklov | right, i was talking about reluctance to use multimethods |
| 15:04 | yoklov | That… doesn't have anything to do with seqs, unless i'm misunderstanding something |
| 15:04 | yoklov | Which is quite possible, as I said, I don't really know clojure. |
| 15:06 | graphbum | yoklov: multimethods pose a design problem as well. the times I have used them, I ended up realizing I'd just defined a protocol (in pieces), but with a guaranteed performance hit. I tend to end up refactoring them into protocols (if I don't need an uber dispatch function). |
| 15:07 | yoklov | that sounds pretty reasonable. |
| 15:07 | graphbum | yoklov: I shouldn't say problem. |
| 15:10 | yoklov | Is there a way to map over a, err, map? |
| 15:11 | yoklov | so (map #(* % 2) {:a 1 :b 2 :c 3}) => {:a 2 :b 4 :c 6} |
| 15:11 | graphbum | you're mapping over the vals in the map |
| 15:11 | yoklov | right. |
| 15:11 | yoklov | is there a way to do that? |
| 15:12 | raek | yoklov: one way is (zipmap (keys m) (map f (vals m))) |
| 15:12 | graphbum | a map is a seq of [key val] |
| 15:12 | graphbum | beat me to punch |
| 15:12 | Vinzent | and the other one is ##(into {} (for [[k v] {:a 1 :b 2 :c 3}] [k (* v 2)])) |
| 15:12 | lazybot | ⇒ {:a 2, :c 6, :b 4} |
| 15:12 | raek | another is (into (empty m) (for [[k v] m] [k (f v)])) |
| 15:13 | yoklov | is the ## just to make the bot eval it? |
| 15:13 | Vinzent | raek, don't know about empty, thanks |
| 15:13 | Vinzent | yoklov, yes |
| 15:13 | yoklov | okay |
| 15:14 | graphbum | there's also fmap in clojure.contrib.genric.functor |
| 15:14 | graphbum | but it's getting into other things you probably don't need. I use zipmap most of the time |
| 15:15 | yoklov | haha, i'll use zipmap i think, after all this isn't haskell :p |
| 15:15 | graphbum | the fact that it can quite nicely approximate haskell is fascinating (to me) |
| 15:15 | graphbum | there's a monad lib |
| 15:15 | yoklov | yeah, it's quite pure and has the required laziness |
| 15:17 | Vinzent | it's sad that pattern matching isn't integrated in the language |
| 15:17 | yoklov | right i was gonna say that |
| 15:17 | yoklov | which makes porting code much more awkward |
| 15:18 | yoklov | or, i imagine it would. |
| 15:20 | AWizzArd | Well, you could simply include core.match into your Leiningen project.clj file and have pattern matching… |
| 15:20 | AWizzArd | https://github.com/clojure/core.match |
| 15:20 | yoklov | I see, I had no clue that existed. |
| 15:21 | AWizzArd | Yes, it is just a one-liner away (: |
| 15:22 | Vinzent | AWizzArd, yeah, and it's very cool, but if I could use it with all my lets and defns it'd be even more cooler |
| 15:23 | AWizzArd | Vinzent: could you give a minimal example of what you would like to do? |
| 15:25 | Vinzent | AWizzArd, e.g. define functions like in other functional languages, something like (defn fac ([0] 1) ([n] ...)) |
| 15:26 | graphbum | pattern matching in the definition itself |
| 15:26 | Vinzent | yep |
| 15:27 | graphbum | I think that has to do with the choice arity in clojure |
| 15:28 | graphbum | it would be really nice though.... |
| 15:28 | graphbum | still, match is pretty cool |
| 15:29 | graphbum | thanks for linking it AWizzArd |
| 15:29 | AWizzArd | core.match will do most useful stuff already. And if anyone has good additions that would fit I am sure the original author would like to talk about it. |
| 15:30 | graphbum | that's in 1.3 ? |
| 15:32 | Vinzent | graphbum, I believe it works with 1.2 too |
| 15:33 | Vinzent | By the way, is there a way to create project templates in leiningen? So e.g. it'd automatically add midje and core.match to all new projects |
| 15:34 | Vinzent | I saw some conversations about this feature on irc... |
| 15:51 | tscheibl | ,(map (fn [[k v]] [k (* v 2)]) {:a 1 :b 2 :c 3}) |
| 15:51 | clojurebot | ([:a 2] [:c 6] [:b 4]) |
| 15:52 | tscheibl | ,(into {} (map (fn [[k v]] [k (* v 2)]) {:a 1 :b 2 :c 3})) |
| 15:52 | clojurebot | {:a 2, :c 6, :b 4} |
| 15:53 | tscheibl | why do you people always use "for"? |
| 15:54 | graphbum | I wondered that too for a while |
| 15:54 | graphbum | in some cases, it's clearer |
| 15:54 | AWizzArd | for can do map and filter at the same time. |
| 15:54 | graphbum | although you dip into a little language to do it |
| 15:54 | AWizzArd | Yes, it is a DSL for List Comprehension. |
| 15:55 | AWizzArd | In that sense map and filter are special cases of reduce. |
| 15:55 | AWizzArd | List Comprehension can do what map and filter offer, but not what reduce can do. |
| 15:55 | tscheibl | hmm I wouldn't consider that clearer |
| 15:56 | AWizzArd | It only needs to traverse the sequence once, and thus might be more efficient. |
| 15:56 | romanandreg | is using a String as a seq of characters a bad idea? |
| 15:56 | tscheibl | .. that's a point .... in case of map AND filter usage |
| 15:56 | AWizzArd | yes |
| 15:57 | AWizzArd | That “yes” was for tscheibl, not for romanandreg (: |
| 15:58 | tscheibl | romanandreg: nah, seems to be a quite natural approach |
| 15:58 | tscheibl | a string is in fact a sequence of characters... |
| 15:58 | graphbum | i think there may be times when you want to use native string ops and java strinb builders (ugh) but the seq approach to manipulating strings is great |
| 15:59 | romanandreg | tscheibl: so, <performance wise> it would be acceptable |
| 15:59 | romanandreg | ? |
| 15:59 | romanandreg | I'm developing a parser combinator library and I'm parsing strings as seqs of characters, that's why I'm asking... |
| 16:00 | tscheibl | romanandreg: If performance is your concern I would test several possible approaches for your application within a (time) |
| 16:00 | tscheibl | .e.g. like Java stringbuf |
| 16:00 | reiddraper | Any ideas how to troubleshoot this error I get when "require"ing one of my namespaces? CompilerException java.lang.VerifyError: (class: knockbox/registers/LWWRegister, method: create signature: (Lclojure/lang/IPersistentMap;)Lknockbox/registers/LWWRegister;) Expecting to find unitialized object on stack, compiling:(knockbox/registers.clj:27) |
| 16:00 | graphbum | good rule of thumb: go with the obvious seq-influenced route, to get obvious and readable code, then if performance is an issue, spot-optimize with less-general stuff (like string builders etc.) |
| 16:01 | graphbum | if performance ends up not being an issue.. declare victory |
| 16:01 | romanandreg | graphbum: cool… I won't do premature optimizations then :-P (just chillax mode) |
| 16:01 | graphbum | i was messing with a toy problem a while back. |
| 16:01 | graphbum | based on string stuff |
| 16:02 | graphbum | got a dictionary of words, like 250K |
| 16:02 | graphbum | in a text file |
| 16:02 | graphbum | define the friend of a word w as any other word with levenshtein edit-distance of 1 from |
| 16:02 | graphbum | w |
| 16:03 | graphbum | you can substitute, remove, or add 1 letter |
| 16:03 | alexbaranosky | reiddraper, I've never seen that error, sorry |
| 16:03 | graphbum | the social network of a word are the friends of its friends, etc. |
| 16:04 | graphbum | problem was to find the social network of an arbitrary word in the dictionary |
| 16:04 | graphbum | used strings-as-sequences just like you described |
| 16:04 | reiddraper | alexbaranosky: thanks, google only seems to find one result too... |
| 16:04 | graphbum | not a big performance problem. |
| 16:05 | graphbum | then again, I did not go back and optimize using lower-level string operations (did not know enough java at the time, did not want to either). |
| 16:06 | tscheibl | ha.. I remember when I started to program in Clojure I used to put typehints almost everywhere (out of performance concerns).... |
| 16:06 | tscheibl | I haven't used a single Typehint now for month now... |
| 16:06 | tscheibl | .. still no performance issues... |
| 16:06 | graphbum | Joy of Clojure had a good section on how typehints can cripple the compiler and hurt performance |
| 16:08 | tscheibl | in essence it's really best to start with the most simpe and general approach and spot optimize if you really hit performance problems (as it already has been said) |
| 16:08 | graphbum | seems like reflection is the enemy of performance, so you want to stamp that out. type-hinting java classes during interop seems to be an obvious case. |
| 16:09 | reiddraper | alexbaranosky: looks like it may be related to this: http://dev.clojure.org/jira/browse/CLJ-837 |
| 16:10 | Okan | hello .. i have a problem on clojure emacs-slime lein instalation |
| 16:10 | Okan | i install lein in standalone bat file |
| 16:11 | Okan | can anybody help me.. i can share the error Message |
| 16:11 | Okan | Debugger entered--Lisp error: (error #("Could not start swank server: |
| 16:11 | Okan | \"C:\\Users\\OKan Aky】\\.lein\\self-installs\\leiningen-1.6.2-standalone.jar\" can not be found. |
| 16:11 | Okan | You can try running \"lein self-install\" |
| 16:11 | Okan | or change LEIN_JAR environment variable |
| 16:11 | Okan | or edit lein.bat to set appropriate LEIN_JAR path. |
| 16:11 | Okan | |
| 16:11 | Okan | " 49 253 (charset japanese-jisx0208))) |
| 16:11 | Okan | signal(error (#("Could not start swank server: \n\"C:\\Users\\OKan Aky】\\.lein\\self-installs\\leiningen-1.6.2-standalone.jar\" can not be found.\nYou can try running \"lein self-install\"\nor change LEIN_JAR environment variable\nor edit lein.bat to set appropriate LEIN_JAR path.\n\n" 49 253 (charset japanese-jisx0208)))) |
| 16:12 | Okan | error("Could not start swank server: %s" #("\n\"C:\\Users\\OKan Aky】\\.lein\\self-installs\\leiningen-1.6.2-standalone.jar\" can not be found.\nYou can try running \"lein self-install\"\nor change LEIN_JAR environment variable\nor edit lein.bat to set appropriate LEIN_JAR path.\n\n" 19 223 (charset japanese-jisx0208))) |
| 16:12 | Okan | (let ((debug-on-error t)) (error "Could not start swank server: %s" (with-current-buffer ... ...))) |
| 16:12 | Okan | clojure-jack-in-sentinel(#<process swank> "finished\n") |
| 16:12 | Okan | |
| 16:13 | graphbum | Okan: where is leiningen-1.6.2-standalone.jar located on your system? |
| 16:14 | Okan | inside the c:\user\Okan AKyüz\.. |
| 16:15 | graphbum | Okan: is LEIN_JAR setup as an environment variable pointing there? |
| 16:15 | graphbum | Okan: or did you modify the path in the .bat file? |
| 16:17 | Okan | the path is conrect |
| 16:17 | Okan | my problem is my surname because it is turkish |
| 16:18 | graphbum | Okan: did you run "lein self-install" ? |
| 16:18 | Okan | yes i did |
| 16:19 | Okan | should i move the file and change any environment setup |
| 16:19 | graphbum | okan: is lein working by itself? can you do "lein repl" |
| 16:20 | Okan | i can run under cmd commond |
| 16:20 | Okan | i cant reach under emacs with clojure-jack-in |
| 16:21 | graphbum | okan: so lein is working fine |
| 16:22 | Okan | graphbum: lein is fine but swank |
| 16:23 | graphbum | okan: is it possible the characterset is messing with the path? |
| 16:23 | graphbum | okan: or not being parsed properly |
| 16:23 | Okan | actually slime runs ccl common lisp fine too |
| 16:25 | pmooser | Has anyone managed to get colorized stack traces from swank-1.3.4 with just normal M-x slime-connect (as opposed to clojure-jack-in) ? |
| 16:27 | graphbum | okan: sounds like pmooser might be the dude to talk to. I am out of depth. |
| 16:27 | pmooser | Whaa ? |
| 16:29 | Okan | graphbum: i set the home environment and LEIN_JAR environment |
| 16:30 | Okan | my problem little bit changed |
| 16:31 | graphbum | pmooser: Okan was having trouble getting clojure hooked up in emacs-slime. given the context of your question, I figured you might be able to help. |
| 16:33 | pmooser | graphbum: It's reasonably challenging … I think the only real path for someone who doesn't use emacs regularly is try to use as much of the magical package.el stuff that technomancy provides to do their setup … As he describes here: http://technomancy.us/149 |
| 16:33 | pmooser | I don't have the option for doing that since at work we can't use leiningen, so I still have to figure out how to do things "the manual way", which is generally not straightforward. |
| 16:35 | Okan | i set the lein i guess |
| 16:35 | alexbaranosky | reiddraper, oh that looks very promising... |
| 16:35 | alexbaranosky | reiddraper, the link that is |
| 16:35 | Okan | i add HOME environment c:\lispemacs |
| 16:36 | reiddraper | alexbaranosky: yeah, i had a param called __meta, just changed it to `metad`. I have funcs that wrap the constructors anyway, so it doesn't really matter |
| 16:36 | graphbum | pmooser: I ditched and went with CCW/eclipse just to get functional.....although I have been lured by emacs. It's still a ways off for me. |
| 16:36 | Okan | i move the .lein folder which is under my user directory to c:\lispemacs\.lein |
| 16:37 | Okan | after that i set the LEIN_JAR |
| 16:37 | Okan | environment |
| 16:37 | pmooser | graphbum: Ah, hm. I can't use CCW for myself because its builder is slightly strange (to me) in that it seems to require an open REPL. |
| 16:37 | Okan | the current problem is swank does not recognize clojure.main() |
| 16:37 | pmooser | I'm actually trying to hack my own clojure builder for eclipse right now, but I know nothing at all about eclipse plugins, and it's not very fun. |
| 16:38 | graphbum | pmooser: yeah, you compile from the repl. |
| 16:38 | pmooser | graphbum: Yeh, our projects at work are largely java-based and I want a builder that doesn't require people who don't use clojure to know what a REPL is. |
| 16:38 | graphbum | pmooser: eclipse isn't great, but it's decent enough. CCW has gotten better over time. I'm not doing any huge projects though, mostly research software (no teams to deal with). |
| 16:39 | graphbum | pmooser: got it. |
| 16:39 | pmooser | Okan: What do you mean that it does not recognize clojure.main ? |
| 16:39 | Okan | pmooser: error code is changed |
| 16:40 | Okan | Debugger entered--Lisp error: (error "Could not start swank server: java.lang.NoClassDefFoundError: clojure/main |
| 16:40 | Okan | Caused by: java.lang.ClassNotFoundException: clojure.main |
| 16:40 | Okan | at java.net.URLClassLoader$1.run(Unknown Source) |
| 16:40 | Okan | at java.security.AccessController.doPrivileged(Native Method) |
| 16:40 | Okan | at java.net.URLClassLoader.findClass(Unknown Source) |
| 16:40 | Okan | at java.lang.ClassLoader.loadClass(Unknown Source) |
| 16:40 | reiddraper | alexbaranosky: do you know if travi-ci has the lein-midje plugin? |
| 16:40 | Okan | at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source) |
| 16:40 | Okan | at java.lang.ClassLoader.loadClass(Unknown Source) |
| 16:40 | Okan | Cou |
| 16:40 | pmooser | Okan, how are you trying to launch the swank server ? |
| 16:41 | alexbaranosky | reiddraper, I'v never heard of travi-ci |
| 16:41 | Okan | pmooser: i start lein like lein new prj |
| 16:41 | Okan | pmooser: under the emacs i C-d to change directory |
| 16:41 | triyo | In leiningen, I'm running `uberjar` and have my own log4j.xml file I wish included. However, my question is what happens when dependency libraries get included with their own log4j.xml files? |
| 16:41 | reiddraper | alexbaranosky: it's a continuous integration service for open source projects, http://travis-ci.org/ |
| 16:42 | Okan | and after that clojere-jack-in |
| 16:42 | triyo | So question is will my own log4j.xml overwrite the lib ones? |
| 16:43 | pmooser | Okan: so you've previously done something like "lein plugin install swank-clojure.1.3.4", and then lein deps ? |
| 16:44 | pmooser | Does just doing 'lein swank' from the command line work for you ? This certainly won't solve your problem but if you are having class path issues I'm curious if lein swank hits the same issues or not. |
| 16:44 | Okan | pmooser: let me try |
| 16:44 | triyo | And if not, can I indicate in project.clj for the dependencies to exclude the log4j.xml file? |
| 16:45 | alexbaranosky | reiddraper, probably doesn't have the plugin -- what would it take to set travis-ci to have it? |
| 16:46 | alexbaranosky | reiddraper, do you have any first impressions or feedback on Midje? I like to hear people's reactions to it -- what they like/dislike, what they miss, etc |
| 16:47 | reiddraper | alexbaranosky: actually just including lein-midje in the project.clj might be enough. I'm not sure if it will be able to "interpret" the output though. Maybe it just uses exit code? |
| 16:47 | reiddraper | alexbaranosky: i've only written one test so far, but my first impression is that midje is _very_ well documented |
| 16:50 | reiddraper | alexbaranosky: ever see this in a test? java.lang.Boolean cannot be cast to clojure.lang.IReference |
| 16:53 | alexbaranosky | calling alter-meta! or reset-meta! on a boolean it sounds like ??? |
| 16:53 | lazybot | alexbaranosky: Oh, absolutely. |
| 16:53 | alexbaranosky | reiddraper, by test do you mean fact? |
| 16:53 | reiddraper | yes |
| 16:53 | reiddraper | alexbaranosky: https://gist.github.com/a550086d332419c55dbc |
| 16:55 | pmooser | Okan, any luck ? |
| 16:56 | triyo | Ok it actually seems that leiningen will prefer the resources from my project as oppose to the dependencies resources. |
| 16:57 | alexbaranosky | reiddraper, I'm not sure what that is |
| 16:57 | alexbaranosky | reiddraper, does it run fine without the with-test? |
| 16:57 | reiddraper | alexbaranosky: ah, yep |
| 16:57 | reiddraper | hmm |
| 16:58 | triyo | so if I have a log4j.xml file, it will prefer it to the dependency lib one when performing uberjar. |
| 16:59 | alexbaranosky | reiddraper, I've never used with-test, but looking at the source it seems to expect a body argument to be passed |
| 16:59 | alexbaranosky | reiddraper, http://clojuredocs.org/clojure_core/clojure.test/with-test |
| 16:59 | alexbaranosky | reiddraper, and voila with-test uses alter-meta! |
| 17:00 | alexbaranosky | ahhhhhhhhhh the fact is evaluating to false/true |
| 17:00 | alexbaranosky | and then the macro tries to alter the meta of that |
| 17:00 | alexbaranosky | reiddraper, and thus the exception you're seeing |
| 17:01 | reiddraper | ah, yep, that makes sense. I'll see if I just can't get lein midje to work on travis-ci |
| 17:01 | reiddraper | so i don't have to wrap with with-test |
| 17:02 | pmooser | OK, well, good luck Okan. |
| 17:02 | alexbaranosky | reiddraper, cool, keep me posted on the travis-ci stuff |
| 17:03 | wingie | what systems are clojure a good fit too and why shouldn't i use node.js? |
| 17:04 | technomancy | wingie: evented IO is really only appropriate for a very small set of computationally-nonintensive problems |
| 17:06 | edbond | Someone has example of using gloss with files? |
| 17:10 | dnolen | wingie: Clojure is a general purpose programming language. It's good for pretty much anything. JVM startup time makes it less than ideal for simple scripting. But you could of course compile to JS w/ ClojureScript and target node.js for that ;) |
| 17:11 | yoklov | what is the equivalent of progn or begin (in other lisps) for clojure? |
| 17:12 | yoklov | (those do a bunch of things in order.) |
| 17:12 | dnolen | yoklov: do |
| 17:12 | yoklov | ah, thanks. |
| 17:14 | wingie | dnolen: i read about clojurescript .. is it considered ready? |
| 17:16 | wingie | technomancy: what intense task would be a good fit for clojure? (can't find anything for me to test it with since im using node.js for web stuff) |
| 17:18 | technomancy | wingie: the evented approach is well-suited for tasks that consist of just routing traffic from one socket to another. everything else needs more flexibility. |
| 17:19 | wingie | technomancy: yeah im using it as web backend between web app and db |
| 17:19 | wingie | but cant figure out what else i would need |
| 17:20 | wingie | perhaps i have no need for clojure yet |
| 17:20 | wingie | but i wanna use it for something :) |
| 17:22 | dnolen | wingie: it's alpha, but it's already useful. |
| 17:23 | wingie | dnolen: the only reason for using it would be the scripting flexibility since java has a long start time? |
| 17:23 | dnolen | wingie: clojure is equally suited for web stuff. IMHO Clojure is a superior language over JavaScript (and I've been doing JS for a long time) |
| 17:24 | dnolen | wingie: yes |
| 17:25 | wingie | dnolen: yeah it seems very capable |
| 17:26 | wingie | and you learn a lot about proper programming |
| 17:26 | wingie | you could easily generate bad code in js |
| 17:26 | wingie | cs (coffeescript) helps a little |
| 17:28 | dnolen | wingie: you can generate bad code in Clojure as well. But I think Clojure has saner, simpler semantics and a richer feature set. |
| 17:28 | wingie | dnolen: it just seems that when i read js book they don't talk as much about proper coding |
| 17:29 | wingie | why i wanna learn clojure's fp |
| 17:30 | reiddraper | alexbaranosky: got it working, http://travis-ci.org/#!/reiddraper/knockbox |
| 17:31 | alexbaranosky | reiddraper, that's really cool, I'll have to check out travis-ci sometime |
| 18:00 | wingie | should impure functions be tested too? |
| 18:01 | amalloy | "should x be tested" => yes for all x |
| 18:01 | technomancy | impure functions need a lot more tests than pure ones |
| 18:23 | yoklov | Hrm, should ``for'' be able to iterate over sets? |
| 18:23 | yoklov | Crap, nevermind. |
| 19:23 | yoklov | yes! my code works now! |
| 19:23 | yoklov | https://gist.github.com/1548720 |
| 19:24 | yoklov | is that code, uh, good style for clojure code? |
| 19:25 | yoklov | i feel like i am swap!ing too many things |
| 19:25 | scottj | yoklov: alignment formatting is uncommon and would be a burden for other people to maintain. |
| 19:26 | yoklov | alignment formatting? |
| 19:26 | amalloy | yoklov: your let bindings have the valeus lined up |
| 19:26 | scottj | (def foo {:bar...) too |
| 19:26 | yoklov | oh, right |
| 19:26 | amalloy | a style i mostly don't care for, but i do have a hacked version of align-let.el that works on clojure's let |
| 19:27 | yoklov | hm, thats sorta a thing i do in almost all code i write |
| 19:27 | yoklov | It's uncommon in clojure? |
| 19:27 | scottj | https://github.com/scottjad/align-cljlet |
| 19:28 | scottj | adds align-map and align-defroutes |
| 19:29 | amalloy | yoklov: i mostly like the approach, and it seems like you're making an effort to minimize mutable state |
| 19:29 | amalloy | or localize it, at least |
| 19:29 | yoklov | yeah |
| 19:29 | scottj | actually origin looks better now https://github.com/gstamp/align-cljlet (except align-defroutes) |
| 19:30 | amalloy | but you don't need the food/snake atoms at all - you can have tick return a food/snake pair instead of modifying the atoms |
| 19:30 | yoklov | i just use align-regex usually |
| 19:30 | yoklov | really? |
| 19:30 | yoklov | hm |
| 19:31 | yoklov | but then i'd have to change the key-event to work differently |
| 19:31 | yoklov | and the drawing |
| 19:31 | yoklov | which I couldn't figure out how to do so i went with mutating the atoms |
| 19:32 | amalloy | well, fair enough |
| 19:32 | yoklov | well no, i'd love to ditch the atoms, if you can suggest the way to have that not happen. |
| 19:33 | amalloy | because you need it to work in paint(), you do need at least one atom somewhere. my preference would probably be to have that atom be a map (or pair) of snake/food, and deref it before you pass it into anything but paint |
| 19:33 | yoklov | and swap it after tick? |
| 19:34 | yoklov | that still doesn't really handle the keypress though |
| 19:37 | amalloy | we've made the whole world into a single atom; it's easy for keypress to change the direction |
| 19:38 | amalloy | also, the way you're using @ and swap! a million times in a single function is not safe at all. if this code were actually called from multiple threads you'd quickly lose integrity. it won't be, because swing only calls you from the dispatch thread |
| 19:39 | amalloy | but if you make the whole world an atom, and then swap! it with a single function that makes all the necessary changes, that problem disappears as well |
| 19:39 | yoklov | i see. |
| 19:41 | reiddraper | alexbaranosky: are there any examples of programmatically generating tests in midje? |
| 19:47 | alexbaranosky | reiddraper, what do mean exactly by programmatically? |
| 19:47 | alexbaranosky | you could use `tabular` or a macro |
| 19:49 | reiddraper | alexbaranosky: I've got some test I'd like to test on some list of input, and i'd like to see them pass/fail separately. looking at tabular now |
| 19:49 | alexbaranosky | tabular sounds like what you want |
| 19:49 | alexbaranosky | it will give you sane output, letting you know which example failed |
| 19:50 | reiddraper | do you have any examples of generating tests with macros? |
| 19:50 | reiddraper | i'm kind of a macro noob |
| 19:50 | alexbaranosky | nope, I never use them, tabular always does what I want :) |
| 19:51 | reiddraper | alexbaranosky: thanks |
| 19:51 | alexbaranosky | tabular is 'basically' a macro that makes a fact for each row of the table |
| 19:52 | reiddraper | cool, it's looking like what I want |
| 20:00 | reiddraper | alexbaranosky: any way i can use (let) in tabular? |
| 20:02 | alexbaranosky | have you tried it? |
| 20:02 | alexbaranosky | you can always (I think) wrap the whole tabular form in a let |
| 20:03 | reiddraper | got it figured out, i was accidently including the table in my let sexp |
| 20:06 | alexbaranosky | a set-based Game of Life implementation: https://github.com/AlexBaranosky/GameOfLife/blob/master/src/retreat1/core.clj |
| 20:07 | alexbaranosky | where the 'cells' are people |
| 20:10 | mrb_bk | dnolen: playing with core.match, it's a lot of fun |
| 20:14 | alexbaranosky | reiddraper, I"m looking forward to see a proposal of what quickcheck-like testing via Midje might look like |
| 20:15 | reiddraper | alexbaranosky: cool. I need to give it some more thought, and play with the Erlang implementation more |
| 20:15 | reiddraper | but will do |
| 20:17 | alexbaranosky | reiddraper, in general I really like to hear feedback on what works/sucks/is-missing from Midje - it helps me think about improvements |
| 20:18 | reiddraper | alexbaranosky: Great. I'm sure I'll have more opinions once I've used it a bit more |
| 20:36 | yoklov | alright |
| 20:36 | yoklov | only one atom now |
| 20:36 | yoklov | https://gist.github.com/1548720 |
| 20:37 | technomancy | alexbaranosky: are you leading up the development of midje these days? |
| 20:37 | yoklov | if anybody has any suggestions on how to make that code any better, i'm very interested :) |
| 20:38 | alexbaranosky | technomancy, It's basically me and Brian Marick, but Marick's really busy and doesn't do as much as he did in the past |
| 20:38 | technomancy | sure |
| 20:41 | reiddraper | anyone using deftype find themselves having to use `lein clean` to get new code to run, even without AOT? |
| 20:41 | wiseen | Can someone help me figure out how to invoke this function http://docs.oracle.com/javase/7/docs/api/java/nio/file/Path.html#register(java.nio.file.WatchService, java.nio.file.WatchEvent.Kind...) ? |
| 20:41 | wiseen | I keep getting java.lang.IllegalArgumentException: No matching method found: register for class sun.nio.fs.UnixPath |
| 20:41 | amalloy | why do you have count in your main-loop at all? you never use it |
| 20:43 | yoklov | oh, thats let over from debugging |
| 20:43 | amalloy | it seems to me it would also lead to nicer code if you represented x/y coordinates as a [y x] pair (or i guess [x y] if you prefer) instead of having to do all this pulling-apart and rebuilding of an x/y map |
| 20:43 | yoklov | i uh, forgot it was there, to be honest |
| 20:43 | yoklov | hm |
| 20:43 | yoklov | thats a good point |
| 20:43 | wiseen | I tried : (.register dir service (into-array WatchEvent/Kind [StandardWatchEventKinds/ENTRY_CREATE StandardWatchEventKinds/ENTRY_DELETE StandardWatchEventKinds/ENTRY_MODIFY])) and simply passing event kinds as varargs but each time I get the exception |
| 20:43 | amalloy | for example, you could do stuff like ##(let [north [-1 0], pos [8 3]] (map + north pos)) |
| 20:43 | lazybot | ⇒ (7 3) |
| 20:44 | amalloy | and write [(dec y) x] instead of {:x x :y (dec y)} |
| 20:45 | amalloy | (case (rand-int 4) 0 :n, 1 :s, 2 :e, 3 :w) => ([:n :s :e :w] (rand-int 4)), fwiw. nitpicky stuff |
| 20:45 | yoklov | yeah, i'm sort of blown away by (map +) haha |
| 20:46 | amalloy | yoklov: you can use a similar map trick to do bounds-checking |
| 20:47 | yoklov | something like (map < [0 0] [x y] [width height])? |
| 20:48 | amalloy | right |
| 20:48 | amalloy | https://gist.github.com/1548959 is a snippet from one of my 4clojure solutions using that technique |
| 20:50 | yoklov | thats very clever |
| 20:52 | alexbaranosky | wiseen, I think the problem might the overloaded method |
| 20:54 | wiseen | alexbaranosky, yeah but how do I tried to add a dummy argument for the second overload : nil and (into-array WatchEvent/Modifier []) |
| 20:54 | wiseen | still get the exception |
| 20:55 | wiseen | is there a way to specify the overload explicitly ? |
| 20:55 | alexbaranosky | wiseen, I saw a solution to this issue a while back, but cfan't recall it |
| 20:56 | alexbaranosky | I distinctly recall cemerick had the solution, but he isn't online now |
| 20:57 | alexbaranosky | wiseen, maybe this'll help http://stackoverflow.com/questions/2722856/how-do-i-call-overloaded-java-methods-in-clojure |
| 20:58 | wiseen | alexbaranosky, saw that :) it's about boxing - that doesn't seem to be my problem since none of the types I'm passing to the function are value types |
| 20:58 | amalloy | wiseen: WatchEvent/Kind shouldn't be a valid thing. you mean WatchEvent$Kind? |
| 20:58 | wiseen | amalloy, nope , let me try that |
| 21:01 | wiseen | amalloy, tnx. that fixed it |
| 21:01 | amalloy | tbh i don't know how WatchEvent/Kind compiled at all |
| 21:01 | wiseen | yeah, just goign to say that, it didn't complain about that |
| 22:43 | graphbum | is there an idiomatic way to serialize a record? |
| 22:43 | graphbum | as a string that can be evaluated with (read-str) |
| 22:43 | amalloy | use 1.3 |
| 22:43 | graphbum | err read-string |
| 22:45 | graphbum | do the record structures just "work" in 1.3? if I (= myrecord (read-string (print-dup myrecord))) evals to true? |
| 22:47 | amalloy | yes |
| 22:47 | amalloy | though i don't know why you're calling print-dup instead of just pr-str |
| 22:48 | graphbum | because I am ignorant |
| 22:49 | graphbum | and behind on versions |
| 22:49 | graphbum | thanks |
| 23:12 | lnostdal | ... :( sometimes all this cool stuff seems worthless when core stuff doesn't work .. stack-traces that doesn't make sense or even end up outside the debugger because heaven-forbid you're using futures or agents or whatever -- with no stack-frame data for variables etc. .. |
| 23:16 | graphbum | I haven't been screwed over by agents yet, but I haven't been using them too much. I hear you on the funky stack traces.....you develop a sixth sense about what errors "really" mean for some things. |
| 23:26 | bitops | hi all, clojure newcomer here - I'm playing around at the repl but having some trouble requiring libraries. If I plug in the code at the top of http://richhickey.github.com/clojure-contrib/generic.math-functions-api.html#clojure.contrib.generic.math-functions/pow I get an error. I'm using Clojure 1.3 if that's any help. |
| 23:26 | lazybot | Nooooo, that's so out of date! Please see instead http://clojure.github.com/clojure-contrib/generic.math-functions-api.html#clojure.contrib.generic.math-functions/pow and try to stop linking to rich's repo. |
| 23:27 | bitops | haha |
| 23:27 | bitops | it's unfortunate that rich's repo is at the top of google... |
| 23:30 | bitops | hm…after looking at the pages, maybe I should change my question. |
| 23:30 | bitops | how do I call the power function? I want to raise some number to another number. |
| 23:30 | technomancy | ,(Math/pow 12 3) |
| 23:30 | clojurebot | 1728.0 |
| 23:31 | bitops | technomancy: there's no Clojure pow function? |
| 23:37 | n0i | newp, alot of basic stuff like that is still missing from core.. have to go to java for it or write your own |
| 23:38 | graphbum | or wrap it |
| 23:39 | bitops | no biggie |
| 23:39 | bitops | it's actually pretty fun to wrap stuff up…learning a lot |
| 23:39 | graphbum | I actually went quite a while without running into that, until I sat flabbergasted at one point (trying to write a simulated annealing function) and I couldn't find exp |
| 23:40 | amalloy | "still missing" in the sense that there's no real reason to write it. in a hosted language there's really no reason to write strlen again, for example |
| 23:40 | technomancy | amalloy: welllll |
| 23:40 | technomancy | Math/pow only returns doubles |
| 23:40 | technomancy | which is why generic-math was written |
| 23:40 | graphbum | no ratios |
| 23:40 | amalloy | yeah, i agree having a real exp would be nice |
| 23:41 | amalloy | but to say that there's "a lot" of stuff that's "still missing" overstates the case |
| 23:41 | graphbum | basic stuff....which requires delegation to the host language |
| 23:44 | amalloy | btw technomancy, the way i found the apt package: $ apt-file find -x completion.*git |
| 23:45 | bitops | I suppose one could argue that Clojure sort of encourages you to delegate to JavaLand - lots of neat stuff to use there. |
| 23:46 | bitops | oh, but I'm reminded, so….what's the best way to require stuff? Looking at http://dev.clojure.org/display/doc/Clojure+Contrib it seems much has changed? |
| 23:47 | bitops | fair to assume that everything in core is auto-required on repl load? |
| 23:52 | technomancy | bitops: all of the clojure.core namespace, yeah |
| 23:53 | bitops | technomancy: that makes sense - I'll be darned if I can require numeric tower though |
| 23:54 | bitops | (require '[clojure.math.numeric-tower]) ;; is incorrect? |
| 23:57 | bitops | …..anyone?….. :) |
| 23:57 | technomancy | that should work if it's in your project.clj |
| 23:57 | graphbum | bitops, how are you running your repl? |
| 23:58 | bitops | graphbum: I'm just starting it via rlwrap java -cp /Users/sebastian/bin/clojure-1.3.0/clojure.jar clojure.main |
| 23:59 | bitops | (rlwrap just for line editing) |
| 23:59 | bitops | technomancy: I'm not running in a lein project |
| 23:59 | bitops | just plain old repl |
| 23:59 | bitops | does that make the difference? |
