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clojurians | clojure | I had a hunch that constantly obviates the need for a macro that creates a do form ```+user=> (def foo (constantly :OK))
#'user/foo
+user=> (foo (println :a) (println :b) (println :c))
:a
:b
:c
:OK
``` | 2017-11-02T18:14:34.000006 | Margaret |
clojurians | clojure | I wonder if it still works for large arg lists | 2017-11-02T18:14:45.000124 | Margaret |
clojurians | clojure | oh yeah, constantly creates a functions that accepts any number of arguments. that invalidates my argument to prefer it over the macro form | 2017-11-02T18:45:12.000251 | Ahmad |
clojurians | clojure | I do not understand what the `n` argument does in practice in `pipeline-async` 0_o | 2017-11-02T19:03:53.000016 | Aldo |
clojurians | clojure | How do I use apply with a Java object? | 2017-11-02T19:04:40.000047 | Alix |
clojurians | clojure | I want to call a method on a java object using the apply function. Is this possible? | 2017-11-02T19:04:55.000048 | Alix |
clojurians | clojure | How do I call a java method with potentially different number of arguments? | 2017-11-02T19:05:16.000231 | Alix |
clojurians | clojure | <@Alix> afaik not without explicitly using reflection | 2017-11-02T19:06:19.000121 | Aldo |
clojurians | clojure | and even if you could figure out how to do it implicitly... it would still be expensive | 2017-11-02T19:06:40.000295 | Aldo |
clojurians | clojure | How expensive is reflection? | 2017-11-02T19:07:01.000095 | Alix |
clojurians | clojure | quite a few orders of magnitude more expensive than a regular function call | 2017-11-02T19:07:23.000275 | Aldo |
clojurians | clojure | but, if you're in a context where you're doing io... not at all | 2017-11-02T19:07:35.000013 | Aldo |
clojurians | clojure | bfabry: <https://dev.clojure.org/jira/browse/ASYNC-163?focusedCommentId=42480&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-42480> | 2017-11-02T19:16:32.000005 | Rebeca |
clojurians | clojure | ta, sounds like what I thought. practically it's only a limit if tasks are completing and sending results | 2017-11-02T19:22:46.000328 | Aldo |
clojurians | clojure | so, let’s say I have used reify on an interface and it closes over on of my Clojure functions. At the REPL, I want to be able to redefine my fn and have the reified object call it. I assume a layer of indirection will do the trick, but what is the best way to achieve this? Use resolve first to get the fn and then invoke it? | 2017-11-02T21:26:28.000025 | Tammie |
clojurians | clojure | <@Tammie> call the functions like this `(#'foo x y)` instead of `(foo x y)` | 2017-11-02T21:46:45.000074 | Sandy |
clojurians | clojure | Although vars work that way already | 2017-11-02T21:47:08.000045 | Sandy |
clojurians | clojure | how do I express the following in clojure:
1. I have a job queue with 1000 items
2. I have 12 worker threads
3. whenever a worker thread finishes a job, it pops off the next job from the queue, and executes it | 2017-11-02T21:59:00.000151 | Berry |
clojurians | clojure | Java has an ExecutorService that is a great match for this but you would use interop for it | 2017-11-02T22:20:07.000100 | Sonny |
clojurians | clojure | Maybe this? <https://github.com/TheClimateCorporation/claypoole/blob/master/README.md> | 2017-11-02T22:20:11.000050 | Kyung |
clojurians | clojure | Or use that ^^ | 2017-11-02T22:20:18.000055 | Sonny |
clojurians | clojure | Which is a Clojurey wrapper for it | 2017-11-02T22:20:45.000195 | Sonny |
clojurians | clojure | <https://docs.oracle.com/javase/7/docs/api/java/util/concurrent/ExecutorService.html> | 2017-11-02T22:20:48.000148 | Berry |
clojurians | clojure | I'm using the ExecutorService. How do I call 'sxubmit' on a clojure function? The problem is that it appears to match both Collable and Runnable ... (fn [] ...) | 2017-11-02T22:21:13.000030 | Berry |
clojurians | clojure | Add a type hint to disambiguate | 2017-11-02T22:22:04.000035 | Sonny |
clojurians | clojure | ah, <https://groups.google.com/forum/#!topic/clojure/MDAIeDDq--8> | 2017-11-02T22:22:06.000011 | Berry |
clojurians | clojure | ^Runnable | 2017-11-02T22:22:16.000043 | Sonny |
clojurians | clojure | (def #^Runnable r (proxy [Runnable] [] (run [] (rand))))
<-- does your solution avoid the 'proxy' ? | 2017-11-02T22:22:35.000212 | Berry |
clojurians | clojure | You don’t need a proxy | 2017-11-02T22:23:28.000114 | Sonny |
clojurians | clojure | ```
(.submit service
^Runnable
(fn []
...))
```
appears to work | 2017-11-02T22:23:31.000153 | Berry |
clojurians | clojure | Yeah | 2017-11-02T22:23:37.000062 | Sonny |
clojurians | clojure | All Clojure functions are Runnable | 2017-11-02T22:23:59.000178 | Sonny |
clojurians | clojure | everything works now; thanks for help | 2017-11-02T22:24:50.000066 | Berry |
clojurians | clojure | in The Joy of Clojure there's a passage stating:
> Clojure functions are highly amenable to interoperability. Their underlying classes implement a number of useful interfaces
does it means that the Clojure compiler wraps Clojure functions into Java classes that under the hood implement some interfaces or something like that? | 2017-11-02T23:03:02.000158 | Ahmad |
clojurians | clojure | qqq's message reminded me of it | 2017-11-02T23:04:42.000090 | Ahmad |
clojurians | clojure | <@Ahmad> Yes, each function is compiled to a class with a number of methods. | 2017-11-02T23:12:26.000189 | Daniell |
clojurians | clojure | <@Ahmad> Here's the ancestors of a function type: ```boot.user=> (defn foo [x] (inc x))
#'boot.user/foo
boot.user=> (class foo)
boot.user$foo
boot.user=> (ancestors *1)
#{java.util.Comparator clojure.lang.AFunction clojure.lang.IMeta java.io.Serializable clojure.lang.Fn java.lang.Runnable java.util.concurrent.Callable clojure.lang.IFn java.lang.Object clojure.lang.AFn clojure.lang.IObj}``` The function compiles to a class called, in this case, `boot.user$foo` (an inner class `foo` in the `boot.user` class which the namespace is compiled to), and it extends/implements all of those listed classes. | 2017-11-02T23:16:15.000115 | Daniell |
clojurians | clojure | <@Daniell> Interesting, so the namespace is also compiled into a class, at least that's what it seems from your example. Does it mean that if I was to create a namespace with `gen-class` its methods would be defined in the `boot.user` class for example and not in an inner class? | 2017-11-02T23:19:51.000116 | Ahmad |
clojurians | clojure | The methods would be defined in the class of the namespace yes (and `gen-class` lets you specify the class name if you want a different one). | 2017-11-02T23:22:18.000082 | Daniell |
clojurians | clojure | It's why the default application you often see has a `(gen-class)` in `whatever/core.clj` and a `-main` function -- and that's compiled to a `whatever.core` class with a `main` method (the `-` is the default convention for `gen-class`). | 2017-11-02T23:24:04.000052 | Daniell |
clojurians | clojure | Woah, I didn't know that, `-main` makes sense for me now :D | 2017-11-02T23:25:25.000071 | Ahmad |
clojurians | clojure | Thanks for your explanations <@Daniell>! | 2017-11-02T23:25:46.000031 | Ahmad |
clojurians | clojure | Also note that anonymous functions get compiled to "unique" class names ```boot.user=> (defn quux [n] (fn [m] (* m n)))
#'boot.user/quux
boot.user=> (def times2 (quux 2))
#'boot.user/times2
boot.user=> (type times2)
boot.user$quux$fn__1879``` | 2017-11-02T23:28:05.000029 | Daniell |
clojurians | clojure | In this case `quux` is compiled to an inner class inside `boot.user`, and the anonymous function is compiled to an inner class called `fn__1879` inside the `quux` inner class. | 2017-11-02T23:29:01.000074 | Daniell |
clojurians | clojure | Nice, it gets deeper and deeper. | 2017-11-02T23:29:56.000007 | Ahmad |
clojurians | clojure | Functions, all the way down :slightly_smiling_face: | 2017-11-02T23:30:03.000128 | Daniell |
clojurians | clojure | :) | 2017-11-02T23:30:12.000022 | Ahmad |
clojurians | clojure | I’m trying to solve an issue we have testing a largish project with `lein test`; occasionally the test run halts with
`Tests failed.
Error encountered performing task ‘test’ with profile(s): ‘base,system,user,provided,dev,humane-errors’
Tests failed.` | 2017-11-03T10:27:46.000549 | Karolyn |
clojurians | clojure | I just cannot get it to be more verbose than that. We’re running this on CircleCI in a docker container and the last test namespace to run seems to be one that contains some clojure.spec generative tests | 2017-11-03T10:29:26.000402 | Karolyn |
clojurians | clojure | other than that no clue. Does anyone have any idea on how I can figure out which test in the test namespace was the last one run or any idea on what the problem might be? | 2017-11-03T10:30:45.000222 | Karolyn |
clojurians | clojure | <@Karolyn> you can log test names by redefining `report :begin-test-var` method: <https://gist.github.com/metametadata/c40a5f099814e591cd627b874f9bb595#file-reporter-clj-L14> | 2017-11-03T11:30:09.000764 | Adele |
clojurians | clojure | oh nice thanks! | 2017-11-03T11:38:04.000194 | Karolyn |
clojurians | clojure | Is there any idiomatic way of getting a map from a sequence of keys (with a value associated with each key based on the key)? | 2017-11-03T14:11:40.000053 | Earlie |
clojurians | clojure | ```
(into {}
(map (fn [a]
[a (derived-value a)])
[:alpha :bravo :charlie :delta :echo]))
``` | 2017-11-03T14:13:00.000204 | Earlie |
clojurians | clojure | I suppose you could replace that `fn` with `(juxt identity derived-value)` but that’s not necessarily any better | 2017-11-03T14:17:14.000253 | Shamika |
clojurians | clojure | Huh, I hadn't thought about that. Thanks | 2017-11-03T14:17:59.000204 | Earlie |
clojurians | clojure | into takes a transducer theses days | 2017-11-03T14:19:46.000422 | Rebeca |
clojurians | clojure | `(into {} (map (juxt ...)) ...)` | 2017-11-03T14:20:06.000512 | Rebeca |
clojurians | clojure | <@Rebeca> Nice, that is pretty concise.
`(into {} (map (juxt identity (partial str :test))) [:a :b :c])` | 2017-11-03T14:21:24.000152 | Earlie |
clojurians | clojure | `(zipmap a (map derived-value a))` | 2017-11-03T14:40:54.000515 | Sonny |
clojurians | clojure | ? | 2017-11-03T14:40:56.000296 | Sonny |
clojurians | clojure | <@Sonny> That certainly works, though I was looking for something that doesn't repeat a or require binding it. | 2017-11-03T14:42:29.000352 | Earlie |
clojurians | clojure | `(apply zipmap ((juxt identity #(map derived-value %)) a))` | 2017-11-03T14:45:38.000460 | Sonny |
clojurians | clojure | <@Sonny> That is quite nice. | 2017-11-03T14:47:22.000711 | Earlie |
clojurians | clojure | that’s awful :) | 2017-11-03T14:47:29.000363 | Sonny |
clojurians | clojure | I’d use zipmap :) | 2017-11-03T14:47:33.000216 | Sonny |
clojurians | clojure | Which is awful? :stuck_out_tongue: | 2017-11-03T14:48:04.000402 | Earlie |
clojurians | clojure | the apply / juxt version | 2017-11-03T14:48:12.000485 | Sonny |
clojurians | clojure | the simple zipmap one is far and away the clearest of these imo | 2017-11-03T14:48:35.000393 | Sonny |
clojurians | clojure | Yeah, I'd agree. | 2017-11-03T14:49:00.000118 | Earlie |
clojurians | clojure | <@Sonny> Good call; zipmap feels cleaner in my actual use case as well. | 2017-11-03T14:52:40.000065 | Earlie |
clojurians | clojure | (Compared to into/map/juxt) | 2017-11-03T14:52:52.000465 | Earlie |
clojurians | clojure | unfortunately, the implementation of zipmap is not as fast as it could be atm, although in the majority of cases you won’t have enough data for it to make any difference | 2017-11-03T14:53:21.000333 | Sonny |
clojurians | clojure | Yeah, there's only 7 keywords. | 2017-11-03T14:53:41.000187 | Earlie |
clojurians | clojure | Good to know though. | 2017-11-03T14:53:47.000320 | Earlie |
clojurians | clojure | I prefer the zipmap, though I want to give lip-service to `medley.core` which has `map-vals` to get rid of the the `(into {} (map...` nastiness, such as ```(map-vals derived-value (zipmap a a))``` It's an extra step, but separating the steps of creating a self-keyed map might be a helpful pattern elsewhere | 2017-11-03T14:55:38.000165 | Cecile |
clojurians | clojure | oh sure, I agree that’s the intent | 2017-11-03T14:56:08.000595 | Sonny |
clojurians | clojure | I wish we had map-keys / map-vals in core | 2017-11-03T14:56:39.000520 | Sonny |
clojurians | clojure | Out of curiosity, why don't we? | 2017-11-03T14:58:55.000006 | Adelaida |
clojurians | clojure | b/c we consider new things for core somewhat rarely and I haven’t gathered the evidence to make a compelling case yet :) | 2017-11-03T15:04:01.000476 | Sonny |
clojurians | clojure | <https://dev.clojure.org/jira/browse/CLJ-1959> | 2017-11-03T15:04:32.000277 | Sonny |
clojurians | clojure | Fair enough. :simple_smile: Ah, thanks for the link, that was my next question. | 2017-11-03T15:04:45.000280 | Adelaida |
clojurians | clojure | vote away :) | 2017-11-03T15:05:51.000277 | Sonny |
clojurians | clojure | Done! | 2017-11-03T15:06:57.000085 | Adelaida |
clojurians | clojure | -> <https://twitter.com/pesterhazy/status/926529085458837505> | 2017-11-03T15:19:26.000004 | Fe |
clojurians | clojure | I wrote map-keys into tools.deps.alpha this week :) | 2017-11-03T15:20:12.000154 | Sonny |
clojurians | clojure | just seeing this, but my 2c — I happened to write map-keys, map-vals, and, just a couple days ago, map-kv in a utils library <@Sonny> | 2017-11-03T15:30:27.000299 | Larissa |
clojurians | clojure | where `map-kv` takes a function of arity-2 | 2017-11-03T15:30:39.000401 | Larissa |
clojurians | clojure | oh sure, there are lots of them out there :) | 2017-11-03T15:30:42.000297 | Sonny |
clojurians | clojure | ```(ImageIO/write (BufferedImage. 10 10 BufferedImage/TYPE_USHORT_GRAY)
"jpg"
(<http://clojure.java.io/file|clojure.java.io/file> "test.jpg"))
```
^-- this returns `false` .
How do I debug this ? | 2017-11-03T15:31:04.000305 | Berry |
clojurians | clojure | I'm attempting to call some Clojure code from a Java project. It seems that when I attempt to do an "import clojure.java.api.Clojure;", it succeeds when I'm pulling org.clojure/clojure 1.7.0 (via Maven), but fails when I pull org.clojure/clojure 1.8.0 since the Clojure class apparently no longer exists. Has this Clojure class been deprecated/moved? (or is there a better way to call Clojure code from Java?) | 2017-11-03T15:31:39.000001 | Lisette |
clojurians | clojure | specter also has MAP-VALS and MAP-KEYS navigators | 2017-11-03T15:31:43.000421 | Aldo |
clojurians | clojure | I suppose I should clarify that my goal is to call code from a library written in Clojure -- so I may be barking up the wrong tree with my approach. | 2017-11-03T15:33:02.000431 | Lisette |
clojurians | clojure | <@Lisette> see <https://clojure.org/reference/java_interop> Calling Clojure From Java | 2017-11-03T15:33:30.000170 | Shira |
clojurians | clojure | the docs say you should use clojure.java.api.Clojure - I don’t see why it wouldn’t find that with 1.8 so I suspect something else is wrong | 2017-11-03T15:34:41.000081 | Margaret |
clojurians | clojure | and I can verify I’ve used clojure 1.8 via clojure.java.api.Clojure in java code | 2017-11-03T15:34:56.000249 | Margaret |
clojurians | clojure | Those are the docs I worked with initially (and then searched around to find some people with the import statements as well) | 2017-11-03T15:35:25.000460 | Lisette |
clojurians | clojure | Hmm. Knowing that it's working for you with 1.8 should be helpful -- maybe I'll just have to wipe my .m2 repo | 2017-11-03T15:35:47.000070 | Lisette |
clojurians | clojure | it is odd that it has only worked for me when I'm pulling 1.7 | 2017-11-03T15:36:05.000135 | Lisette |
clojurians | clojure | hey all, can I ask a very n00b clojure question? | 2017-11-03T15:36:20.000372 | Floretta |
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