run! is probably what you want there

https://github.com/clojure/clojure/blob/clojure-1.9.0-alpha14/src/clj/clojure/core.clj#L7585

Oh nice, thanks - TIL

Thanks for the advice!

I'm using clojure/java.jdb quite a lot and I'm pondering how to cancel abandoned requests. I don't see a place to do this, or a way to extract the jdbc statement to do it directly, anyone know if this is something that already exists? Of if there is somewhere else I should be asking about this?

I'm sure there is a better way to achieve that, someone has an idea ? (def pos ["zero" "one" "two"]) (for [i (range (count pos))] (print i " - " (get pos i))) I don't like to call get each time

Vectors are associative, so this works:

(reduce-kv
  (fn [_ k v]
    (println k " - " v))
  nil
  pos)

Thanks! I'm going to dig it

@tbaldridge and if I want to return something instead, for example a map {:i k 😛 v}, reduce isn't helpful here ?

a reduce can return any type you like

Sorry, I meant if I want to return a map for each element in the vector

yes, reduce can do that

+user=> (reduce-kv (fn [acc k v] (conj acc {:i k :p v})) [] ["zero" "one" "two"])
[{:i 0, :p "zero"} {:i 1, :p "one"} {:i 2, :p "two"}]

...

I'm so tired xD

I forgot about the acc, thanks!

I should bench them for fun 😛

Even if my collection is less than 20 elements... ><

Is WhaleSong the only Racket -> JS compiler, or is Carmark using something else to do Racket -> JS ?

Just getting started with Apache Spark. I'm wondering if there's a best™ library to interact with it?

https://github.com/yieldbot/flambo, https://github.com/gorillalabs/sparkling and https://github.com/HCADatalab/powderkeg, of which the last one is really interesting 🙂

Do we have anyone here who’s using Clojure and AWS Lambdas in production? Opinions on it?

🙋

have been using Clojure based Lambdas for more than a year now

been quite happy

@looveh @mhjort (of https://github.com/mhjort/clj-lambda-utils) can likely answer your questions

but the really neat thing is this: https://github.com/cgrand/portkey

Portkey will really shake things up 🙂

think live coding Lambdas, not in the AWS GUI, but in your familiar repl

just picked my jaw up off the table.

😄

not yet ready, but let’s see 🙂

if we start to talk about it in public, let’s create a channel #portkey

How should I name: - A function that finds the closest date of a given weekday in the past or today - A function that finds the closest date of a given weekday in the future or today ?

@not-raspberry last-weekday-date?

given it's impure, better start with a verb https://stuartsierra.com/2016/01/09/how-to-name-clojure-functions

Presumable accept the given date as the first param to make it pure 🙂

It doesn't need to be impure, it can accept now as an argument.

The actual problem is that while 'last' may imply that today is accepted, 'next' doesn't.

so next-weekday-date is an iffy name

I'd stick close to the new java time api. previous-or-same. See java.time.temporal

how about most-recent-weekday-date?

Thanks.

I changed the code to assume a week range from the current week, so I don't need those functions 🙂

Developing code intended to be primarily used from the REPL exhibits an interesting conflict between user-friendliness and consistency.

Clojure 1.9 / clojure.spec split https://groups.google.com/forum/#!msg/clojure/10dbF7w2IQo/ec37TzP5AQAJ

@coltonoscopy I used play-clj to produce a commercial point-and-click adventure (tick’s tales)

Hi, I have immutant in project as a dependency which adds wunderboss-core as dependency which comes with a logback-default.xml in its jar. When starting my server the logback-default.xml takes precedence over my own log4j.xml that I have in my resources folder. The same happens when creating an uberjar. Is there a way to configure the priority of the log configurations?

@sveri http://immutant.org/documentation/current/apidoc/guide-logging.html#h3341

@jcrossley3 Thanks, I will be trying this, should have checked the docs first

@coltonoscopy @brycecovert I'm taking the freedom to link @brycecoverts dev blog: http://www.tickstales.com/dev-blog/ It's pretty awesome!

(and I just bought the game 🎮 )

@curlyfry - thanks! wow! Blogging is really hard, it means a ton to have someone say it’s insightful!

and I hope you like the game! Probably more relevant to folks here might be my talk at clojurewest last year: https://www.youtube.com/watch?v=lql2yFXzKUs

Is there a good/common way to (centrally) throttle/rate limit outgoing http requests? I need to call an API many times (from different parts of my app) but am being rate limited on their end and want to control my request rate. Thanks.

@juliobarros core.async is good for doing this, essentially you can use pipeline-async or pipeline-blocking to explicitly set you parallelism.

You can complement this by implementing exponential backoff, which again is fairly easy to implement with core.async

Thanks @val_waeselynck do you know of a gist, example or library that takes care of all the details? Btw, you are vvvvalvalval aren’t you? Great name 🙂 and I’ve used your libraries! Thanks.

wow thanks 🙂

yes that's me

exponential backoff:

https://gist.github.com/vvvvalvalval/2fc2067cb96270396154dca34a85c083

Beware that the parallelism at least for pipeline-async (not sure about pipeline-blocking) is not precise. See https://dev.clojure.org/jira/browse/ASYNC-163 for some details.

is there a style preference for t/testingmacros? I feel like writing a bunch of prose is appropriate but Clojure doesn’t really have an applicable multiline string literal, right

@juliobarros as for http req throttling, here's the basic idea:

Thanks @val_waeselynck I’ll check out the gists.

> Clojure doesn’t really have an applicable multiline string literal

@lvh What do you mean? What's wrong with clj string literals ?

there’s no multiline string literal like e.g. Python’s """/`'''` that editors know about

so you can’t write long prose entries in t/testing without telling everyone to soft-wrap

@lvh yes there is, unless we don't talk about the same thing

(def(n) docstrings are a notable exception)

OK; what does a long clojure.test/testing string look like?

;; this is valid clojure "a multi line string"

there’s a subtle difference there; Python’s docstrings (not strings in genearl) don’t carry that formatting data around with them, and IIRC cljfmt doesn’t really like what clojure-mode does with filling those by default (except for docstrings): the indendation matches the (t/testing ...) baseline, not testing + 2 or the opening quote for the string

but mostly what I’m asking is: is there something of a style guide standard around this

oh

not that I know of

(clojure-style-guide does not)

Maybe you should write a (multiline s1 s2 s3 ...) macro 🙂

that sounds like it’d make editor integration a lot worse than just fixing string-literal-with-newlines-in-it

yeah you're right

didn't think it through

anyway, thanks for the soundboard, at least I’m not missing the obvious

as clojure is homoiconic, just wondering if there's any cool code refactoring library out there, I might not know how to google for that, or, nothing I found on my own looks quite stellar

e.g. I'm manually replacing one library with another across my source files in one project, and in a different universe I'd write a program that does it for me (go through all sources, find and replace under ns definitions in this one case, maybe make a backup.

I'm sure to write this one day, just wondering if there's already something out, possibly covering more useful concerns than I am thinking of

@matan I’ve written a program that did some complex searching for certain patterns in a clojure program using slamhound’s asplode (https://github.com/technomancy/slamhound) - may be helpful

I didn’t use it to manipulate any code, only to find certain patterns, but it seems like that might be half the problem for you

aspload? https://github.com/technomancy/slamhound/blob/master/src/slam/hound/asplode.clj

I thought slamhound was only for namespace stuff

yes, that

so you just tore apart / borrowed that source for your use case?

I didn’t need to change it at all; I just used asplode as is

You can use it to read in a clojure file, and then tree walk

Mmmmm

It worked great for my use case; specifically finding all string arguments to any usage of a few functions within my program

@brycecovert i watched your talk several weeks back and was inspired by the way you did your cutscenes 🙂

@brycecovert would that happen to be public code?

@matan No, but I’d be happy to send it to you privately. 😉

@coltonoscopy thanks!

A very fun problem, cutscenes. I’d be interested in taking it further, which I’ve been experimenting with, lately 🙂

@matan look at refactor nrepl, it has features that will help

@brycecovert yes and anything asynchronous, it applies well to turn-based games like the kinds i enjoy/want to write 🙂 (say, you want a character to walk to a tile in the battle grid, then cast a spell, etc.)

to get it as concise as you did takes a lot of work though

@coltonoscopy absolutely. There are many different approaches to those problems, like finite state machines, building your own scripting language, etc. core.async was a great answer - you get to write your game scripts in clojure, and it looks synchronous!

Happy to take it offline for more brainstorming for your game. 🙂

awesome, thanks! 🙂

Are there opinions on ease of implementing component vs. integrant? I have a Ring app I need to iterate on and I'm too impatient to restart my REPL 😉

@mattly hi btw

@bradford you’ve probably spent more time than you’ll likely save by not just grabbing one and starting 🙂

@robert-stuttaford hahah story of my life

@bradford For me personally, Integrant was a lot easier to understand

i like the look of integrant, personally, although i’ve never directly used either

I used component a few years ago. Although my current design pattern is 'atoms errywhere'

There are probably more resources for Component, but I think they generally apply to Integrant as well

I could use some feedback on something I'm puzzling over. I'm building a HTTP proxy that needs to have a weird architecture. The client hits a /upload endpoint which takes a multipart-form and content-type. It then transforms that to a Ring-based HTTP response with the proper content-type. This works fine for text content. But binary content isn't quite right. An image/jpeg is corrupted, with the browser seeing it as a text blob with size of 0. I feel I'm not "casting" the data correctly, but I'm not sure how to fix it. Just setting the Response content = the content of the multipart-form isn't right.

Maybe making the response body a input-stream is the key...

how are you specifying it now? file or input-stream should work

and anything that comes from a reader (like slurp) is likely broken

how do grownups merge maps of arbitrary depths?

(merge-with
  (partial merge-with merge)
  {:a {:b 1}
   :c 2}
  {:a {:d 3}})
=> {:a {:b 1, :d 3}, :c 2}

There's about 10 different ways to merge keys that collide during a deep merge

So either you can write custom merge logic, or switch to a structure that doesn't require you to merge nested maps.

One of those two is what I normally end up doing ^^

thanks @tbaldridge, that's what I expected.

https://github.com/sonian/carica/blob/master/src/carica/map.clj

with transit-clj, when reading multiple records from an InputStream, what’s the best way to detect the InputStream has no more records to read? (ie, the client can send a variable number of records, then close the socket) i see that when (transit/read) is called when there is nothing to read, a RuntimeException is thrown, but that’s not the normal use case, is it?

Whats the idiomatic way to make a list of a finite length which expels elements by fifo?

clojure.core.cache?

@laujensen if you’re trying to make a FIFO cache, then yeah. If you want a generic coll for that, you could probably use https://github.com/amalloy/ring-buffer , if you were trying to make a core.async buffer, you can use https://clojuredocs.org/clojure.core.async/sliding-buffer

Thanks @tanzoniteblack , I'll checm 'em out

Im just trying to make a really slim login-attempt logger which checks for high frequency attempts

yeah, a ring-buffer sounds great for that (but a loop with a clojure.lang.PersistentQueue that does a pop and a conj on each iteration works too and doesn’t require a dep)

Just looking through ring-buffer it looks as lean as it gets, but thanks for the example

How did you activate the bot ?

you can use /clj

Has anyone found a way to calculate the size of an object? I know its possible on .net now

structural sharing makes that ambiguous no?

Not really

a big percentage of live data in my app shares data with some other object also live in the app, it just has a few keys updated

just measuring its size as a tree would be misleading about its actual heap usage

Well, actually you were right, it would be ambigious, but then its also a choice you have to make, regarding how you weigh the shared data. But in most cases, I figure you want the whole deal. But check out the efforts on .net

yourkit lets you see the total size of referenced data in an object

but my experience was that so much of the data was shared between multiple hash-maps and lazy-seqs and vectors that I still had to do a lot of work to know what the real memory culprits were

one thing I found very useful was creating defrecords to replace hash-maps, just so the profiler would be able to look them up and summarize them quickly by name

but not defining any keys or methods, just a defrecord used like a map

Ah, I havent made that distinction, but I'll try it out. Youre probably right

Anyone want to give any software talk recommendations?

Any specific topic?

@laujensen nope! Just looking for what someone else finds interesting.

https://www.youtube.com/watch?v=gsffg5xxFQI

That one was interesting re the js landscape

great thanks!