#clojure log - Feb 14 2016

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5:45 vivekramaswamy: A quick question, I am getting a stack overflow in this small clojure program, not sure why ideas would help? http://shortText.com/736de871

5:48 blur3d: vivekramaswamy: you’re not using the correct recursion syntax

5:49 You use ‘recur’ instead of your function name - https://clojuredocs.org/clojure.core/recur

5:49 vivekramaswamy: ok, got it, thanks a lot

6:05 LauJensen: Gents, is there a switch which detect if AOT compilation is running? I have a java lib that dies if its called during AOT compilation, so I need it to bypass a certain line until the app is actually launched

6:11 vivekramaswamy: Hello blur3d, I did the change, but still end up getting a compilation error, any ideas, https://codeshare.io/F4J46

6:16 blur3d: vivekramaswamy: Well, you’re missing a closing paren

6:21 vivekramaswamy: Thank you blur, working off a textpad is a pain while using clojure, any easy to use editor other that emacs that you are aware of, that wil check for parens

6:29 blur3d: vivekramaswamy: What do you want the function to do? Print out each item in the list one by one?

6:31 if so, no need for recur… just use (map #(println %) '(1 2 3))

6:31 ,(map #(println %) '(1 2 3))

6:31 clojurebot: (1\n2\nnil 3\nnil nil)

6:31 TEttinger: ,(map println [1 2 3])

6:31 clojurebot: (1\n2\n3\nnil nil nil)

6:32 blur3d: vivekramaswamy: lighttable is fairly friendly.. i’d give it a go

6:32 TEttinger: ^ blur3d

6:32 no need for anonymous fns wrapping something if it's being called with the args as-given

6:33 blur3d: TEttinger: that works also, haha… haven’t written clojure in over a year now

6:33 TEttinger: ,(map str '(a b c) [1 2 3])

6:33 clojurebot: ("a1" "b2" "c3")

6:33 TEttinger: ,(map str '(a b c) [1 2 3] "?!@")

6:33 clojurebot: ("a1?" "b2!" "c3@")

6:34 TEttinger: I love how versatile the seq abstraction is

6:34 strings are seqs of chars! now everything's easier!

6:35 blur3d: Yeah. I really loved using clojure.. I’ve just changed my line of work

6:36 I have a personal project that is highly data driven and lazy, so I hope to prototype it in clojure soon

6:37 vivekramaswamy: Nope blur3d, I was just reading a book and trying out recur, you are right for something as simple as this I can use a map, but I just wanted to try doing it using recur

6:38 noncom: how to make a server built on ring/compojure accept params passed in url, like "http://some-url?id=1&something_else=2

6:57 blur3d: noncom: http://stackoverflow.com/questions/7785214/compojure-how-to-map-query-parameters

8:03 side_effect1: hello. I started learn clojure with clojurescript repl. I want to reproduce this code in repl [datascript.core :as d] context https://github.com/bnomis/om-next-datascript-localisation-demo/blob/master/src/om_next_datascript_localisation_demo/datascript/db.cljs#L5

8:04 I know I should start from basic and the I can write some combination from marcos import, def, refer

9:16 justin_smith: side_effect1: (require '[datascript.core :as d]) works in a repl

9:16 side_effect1: also, you can run the ns form exactly like it is there, in a repl

9:21 side_effect1: justin_smith, thanks. It works.

9:22 justin_smith: side_effect1: in general there are very few things you can do in a source file that you can't do in a repl

9:22 (and even with those there's a way to do it if you really want to)

9:23 hodwik: Any idea why in Emacs I would get Namespace not found. for everything in the repl

9:23 including simple stuff like (+ 1 1)

9:24 justin_smith: hodwik: because you ran (in-ns 'some-ns) for an ns that was not loaded yet

9:24 hodwik: run (clojure.core/refer-clojure) to restore sanity

9:24 hodwik: Namespace not found. :L

9:25 justin_smith: even (clojure.core/refer-clojure) doesn't work?

9:25 hodwik: Yeah

9:25 justin_smith: because clojure.core is kind of needed in order to have a repl at all...

9:26 hodwik: Yes, that makes sense

9:26 justin_smith: wait, is "namespace not found" a clojure error or a CIDER one I wonder?

9:26 because it could be CIDER is just in a broken state

9:28 hodwik: So, the repl works until I change namespace to my project

9:28 then nothing works

9:28 justin_smith: how are you loading your project namespace?

9:28 is it automatic? are you sure it is actually happening?

9:28 hodwik: C-c M-n from the .clj window

9:32 How about I rewind a step, is there an out-of-the-box emacs setup for clojure

9:32 because I suspect I am setting something up incorrectly, but there's too many moving pieces for me to figure out what it is

9:34 justin_smith: hodwik: best practice with cider is to nuke it all (plugin for clojure and all elisp / elc related to clojure), then reinstall a specific version. And never do in-place incremental updates.

9:34 Always remove everything before updating.

9:35 frankly I got tired of the breaking things and just use a repl in a terminal now. (require 'foo.bar :reload) after saving a file does as much as I actually need

9:36 hodwik: I don't blame you, this emacs/clojure integration seems very touchy

9:36 This is install attempt 3 for me, still can't get it to work as described in the braveclojure book

9:37 justin_smith: actaully for files in another project, on disk, but loaded as a dep from a jar, you also occasionally need (load-file "/full/path/to/file.clj")

9:37 but anyway those things are pretty much all that's needed to redefine anything at runtime, which is the amount of integration I really need.

9:38 hodwik: So you're just using lein from terminal

9:39 what about for editing?

9:39 justin_smith: emacs

9:39 just clojure mode

9:39 hodwik: Oh, but you just run your code in the term window?

9:39 justin_smith: right, using require or load-file as apropriate to load new definitions

9:40 hodwik: I'm comfortable with that workflow, I think I'll switch to that

9:40 thank you

9:40 justin_smith: when working that way, clojure.repl/dir and clojure.repl/apropos become very usefil

9:40 *useful

9:41 hodwik: I'll take a look at those

10:25 LauJensen: Gents, is there a switch which detect if AOT compilation is running? I have a java lib that dies if its called during AOT compilation, so I need it to bypass a certain line until the app is actually launched

10:26 justin_smith: LauJensen: the standard way to do this is to put the line in question inside a function that gets called. Or does the line cause this error even inside a function body definition?

10:28 LauJensen: justin_smith, Its the instantiation of a global. I could wrap it in an atom and init it in -main

10:28 justin_smith: LauJensen: you can also use declare, and actually assign the value in -main

10:29 or even use a delay

10:29 no need for an atom if it isn't going to get multiple values at runtime

10:29 LauJensen: A delay?

10:29 justin_smith: ,(def foo (delay (do (println :realized) :OK)))

10:29 clojurebot: #'sandbox/foo

10:30 justin_smith: ,foo

10:30 clojurebot: #object[clojure.lang.Delay 0x54ae79a7 {:status :pending, :val nil}]

10:30 justin_smith: ,(realized? foo)

10:30 clojurebot: false

10:30 justin_smith: ,@foo

10:30 clojurebot: :realized\n:OK

10:30 justin_smith: ,@foo

10:30 clojurebot: :OK

10:30 LauJensen: Oh right

10:30 justin_smith: the code in delay gets called once, on first deref, then it holds that value

10:30 LauJensen: Good tip, thanks

10:31 In my test, delay fires immediately

10:31 justin_smith: are you dereffing immediately?

10:31 LauJensen: no

10:32 justin_smith: umm... then you are doing it wrong somehow

10:33 LauJensen: try this, (def tst (javax.swing.JOptionPane/showMessageDialog nil "TST"))

10:33 and on my system, it pops before dereffing

10:33 justin_smith: umm, that's nopt delayed

10:34 LauJensen: (def tst (delay (javax.swing.JOptionPane/showMessageDialog nil "TST")))

10:34 that won't pop the window until you run (deref tst) or the equivalent @tst

10:34 (just verified in my own repl)

10:38 LauJensen: also I discovered that call returns nil - it's not a value at all just a side effect. Which makes me think you don't want a delay, just a function call.

10:38 (if that's equivalent to what your code was doing)

10:39 LauJensen: sorry, i just forgot to type delay in here, had it in the repl

10:39 No wait, i didnt, nevermind :)

10:39 justin_smith: haha

10:41 LauJensen: Thanks for taking the time Justin

11:03 insamniac: anyone use quil much? I'm trying to figure out the best/right way to handle input from a channel

11:05 benjyz1: is there any good irc channel for web-security?

11:05 insamniac: my simple brain wants to make the channel read to update some mutable external state, and have quil :update look at it

11:05 benjyz1: ..maybe someone here knows

11:06 insamniac: ##security maybe

11:20 or i guess if i'm smart I can just read the channel during my :update fn

11:20 arkh: deny user input by default and allow only if input matches the right regex and min/max length

11:23 noncom: justin_smith: ping

11:24 justin_smith: hello, noncom

11:24 noncom: hi! now implementing the idea of a separate login page, and i lose the ani-forgery item on the login form POST erquest :/ do you know, how can I handle this?

11:25 justin_smith: you'll need to generate the login page on the server side and include the token in the submission form

11:25 noncom: i return the app html page in response to a correctly authorized request, but then the requests that are done from that page, like css requests, lose the token

11:25 ah.. ok, i am generating the login page from a template.. how do i include the token?

11:26 justin_smith: as a hidden field on the form

11:43 noncom: justin_smith: ok, for example, i create that field, say, i name it "csrf-aft", then how do i interpret it on the server? i have the ring middleware that cares for csrf, but how to make it recognize it

11:43 ?

11:49 got some info here: http://www.luminusweb.net/docs/security.md now studying

12:04 justin_smith: it worked! :) now - another question - how do you then come back to "http://host/#/single-page-app-address" addressing? because i now have "http://host/login/#/single-page-app-address" ..

12:04 the "/login/" part should not be thre

12:04 *there

12:05 justin_smith: noncom: via the target field of the form

12:05 or a redirect

12:05 either one works

12:07 noncom: justin_smith: hmm what do you put in there? neither _blank nor _self seem to fix this..

12:08 justin_smith: sorry, not target, I mean action d'oh

12:09 but then whatever path that posts to has to be ready to take a login, of course, and respond with the app if apropriate

12:09 so it might make more sense to redirect after success

12:10 noncom: justin_smith: ehh.. i am soo noob in the web.. okay, if i generate a token for a correct login attempt, then, if i redirect to another page which contains a web-app, how do i maintain the token on the client side and authenticate with the SPAPP correctly?

12:25 * this time i meant an auth token, not the csrf one

12:25 TimMc: Is there still a point in using # instead of ? given that all modern browsers support the History API?

12:26 noncom: TimMc: is this a general question or per my asking?

12:28 TimMc: general

12:29 noncom: justin_smith: if i don't redirect but instead give the page as a direct response then i can embed the auth token into it, but it won't work with redirect like that.. :/ or should i somehow pass the parameter with redirect? will it shuttle first to the client and then back to the targeted redirect page?

12:29 TimMc: There was this awkward period after SPAs became trendy but before the History API was a thing, and it was terrible -- people used various combinations of # and ? for resource paths. But now there's the History API and it's pretty well supported, so I'm not sure what the point of using # is.

12:30 noncom: TimMc: i am not really sure easy. i use the "session" middleware which implies using "#" as the path indicator..

12:33 justin_smith: TimMc: it allows following vanilla href links without page loads

12:35 TimMc: justin_smith: I think the idea is to intercept those clicks.

12:35 justin_smith: also it allows arbitrary content in links/ locations - anything after # is legal

12:36 TimMc: with # I don't need to intercept anything

12:36 much simpler

12:36 TimMc: hmm

12:36 justin_smith: TimMc: different routes in my SPA don't represent separate server resources

12:36 TimMc: ah

12:37 justin_smith: they represent different approaches to the app feature set, all backed by the same data

12:37 TimMc: I mean, I also don't like AJAX-for-main-content in the first place, I think it's terrible, and I generally assume that complexity is what you've signed up for with SPAs...

12:37 justin_smith: TimMc: of course if different pages represent different wholly distinct server resources, that can be different I guess

12:37 TimMc: also endless synchronization issues

12:37 Github is *forever* getting out of sync with its URLs.

12:38 justin_smith: TimMc: the frontend knows how to display data, the backend knows what data should be displayed. The backend has no view logic. This isn't super complex - there are other sources of complexity but this part just works.

12:38 for my app at least, ymmv with other designs of course in various ways

12:39 bbl heading to the office

13:05 sevvie: i suck with clojure, but I used it to make a valentine's gift for my beloved. http://github.com/sevvie/vacant-riddles

13:33 justin_smith: if I weren't miserable and doomed to die alone I'd check it out

13:33 j/k looks cool, nice concept

13:35 rhg135: I have yet to find a girl who appreciates my unique abilities

13:35 Darn, that sounds so hipster

13:36 justin_smith: nah, just old-fashioned conceited

13:36 :)

13:37 hipster would be "I have yet to find someone who appreciates my discerning and obscure taste"

13:37 rhg135: I mean that in a totally not conceited way

13:38 hlolli: Humanity woulde evolve quickly if Clojure programmers were as sought after as bodybuilders. Same applies for female Clojure programmers.

13:39 rhg135: When I talk to a girl I mention code and her eyes glaze over

13:39 futuro`: rhg135: talk to different women?

13:40 rhg135: Maybe that'll work, futuro`

13:40 futuro`: goodspeed!

13:41 man, I am losing my mind trying to fix an om bug

13:41 * rhg135 looks at the calendar

13:41 justin_smith: rhg135: no time to lose, you know tonight is the best night possible for a first date!

13:41 futuro`: ooo, so true!

13:42 rhg135: I rather dislike the idea of dating

13:42 futuro`: as in, the common approach to a "date", i.e. dinner, a movie, some semblance of conversation?

13:43 hlolli: My flatmate and my neighbours are having sex. Im developing website and eating Ben Jerrys icecream to survive :)

13:43 futuro`: hlolli: I'm glad to hear that your flatmate is on such good terms with your neighbours

13:43 rhg135: No, the concept. Spending time with someone only to have it end suddenly

13:44 hlolli: not what I ment, BUT you are actually right, she is in faact having sex with our flatmate.

13:44 I mean neighbour and my flatmate. They fell in love.

13:44 futuro`: hlolli: neat!

13:44 hlolli: But I also hear sounds from the apartment below, so the love is in the air

13:44 futuro`: I rarely even /talk/ with my neighbors, let alone fall in love with them

13:44 justin_smith: rhg135: dates need to be relationship complete, which means you can't know without running them whether or how they end.

13:45 rhg135: That's not really love though

13:45 justin_smith: oh god that was a tortured metaphor or something

13:45 rhg135: Lol

13:45 futuro`: justin_smith: it's the perfect day for them ;)

13:46 rhg135: Try saying that to your gf

13:47 hlolli: By the way, is anybody going to :clojureD next weekend in Berlin?

13:47 futuro`: rhg135: it's incredibly difficult not to say cheesy things during inappropriate times with my SO

13:47 the struggle is real

13:48 rhg135: I'm hoping she's OK with that

13:48 futuro`: oh yeah, I wouldn't date them if they weren't

13:48 but, you know, all things in moderation

13:50 rhg135: Moderation is always a good strategy

13:51 justin_smith: moderators violate the first ammendment down with mods

13:51 * justin_smith is bad at jokes.

13:51 futuro`: First amendment means I can say anything I want without repercussions!


13:53 rhg135: Is America in some alternate universe?

13:53 justin_smith: no, but 'murika is

13:53 rhg135: Sounds like a good idea

13:56 Land of being called a bunch of explicit words while being filled with lead by your neighbor

13:56 'murica that is

13:56 futuro: That's exactly right; I know, I'm 'murican!

13:56 justin_smith: rhg135: basically it's a tarantino movie

13:57 rhg135: I don't know what that is.

13:57 * rhg135 just nods

13:57 futuro: a movie by this dude https://en.wikipedia.org/wiki/Quentin_Tarantino

13:57 justin_smith: rhg135: quentin tarantino - did pulp fiction, reservoir dogs, hateful eight...

13:58 futuro: django unchained

13:58 rhg135: Oh!

14:05 noncom: justin_smith: can you possibly give an advice on how to maintain authentication throughout the redirect? As I understand, the redirect will make client to request a completely different page, how do I maintain the authentication token with it? Do I somehow store it in the redirect response that I give from the compojure router?

14:05 justin_smith: noncom: the page you redirect to should give the client a new token, etc.

14:06 noncom: justin_smith: oh, so you mean that if the redirect happens, this already implies authentication? but how do i pass the identity of the user to the new page?

14:06 justin_smith: when you return a redirect, you can then expect the client to hit the other page that you redirect to, that page can offer an auth token

14:07 noncom: how do i know it is the same client who passed the authentication?

14:07 justin_smith: you can attach a paramter to the request string in the redirect

14:07 that's the easiest at least

14:08 and that string can be the one time token, etc.

14:10 noncom: justin_smith: oh... a shuttle

14:10 i see

14:10 makes sense with the 1-time use tokens, right!

14:11 justin_smith: thank you so much, you can answer various web-related question very clear, i really appreciate that!

14:12 justin_smith: noncom: np, glad I could help

16:20 benjyz1: hello. I want to a transformation of a map https://www.refheap.com/114795

16:20 ,(def x {a {foo 0, bar 22}, b {foo 3, bar 44}})

16:20 clojurebot: #error {\n :cause "Unable to resolve symbol: a in this context"\n :via\n [{:type clojure.lang.Compiler$CompilerException\n :message "java.lang.RuntimeException: Unable to resolve symbol: a in this context, compiling:(NO_SOURCE_PATH:0:0)"\n :at [clojure.lang.Compiler analyze "Compiler.java" 6688]}\n {:type java.lang.RuntimeException\n :message "Unable to resolve symbol: a in this context"\n ...

16:21 justin_smith: ,(map (fn [k v] (assoc v :id k)) {a {foo 0, bar 22}, b {foo 3, bar 44}})

16:21 clojurebot: #error {\n :cause "Unable to resolve symbol: a in this context"\n :via\n [{:type clojure.lang.Compiler$CompilerException\n :message "java.lang.RuntimeException: Unable to resolve symbol: a in this context, compiling:(NO_SOURCE_PATH:0:0)"\n :at [clojure.lang.Compiler analyze "Compiler.java" 6688]}\n {:type java.lang.RuntimeException\n :message "Unable to resolve symbol: a in this context"\n ...

16:21 justin_smith: ahaha

16:21 ,(map (fn [k v] (assoc v :id k)) '{a {foo 0, bar 22}, b {foo 3, bar 44}})

16:21 clojurebot: #<ArityException clojure.lang.ArityException: Wrong number of args (1) passed to: sandbox/eval72/fn--73>

16:21 justin_smith: er

16:21 benjyz1: I'm getting a strange format

16:21 justin_smith: ,(map (fn [[k v]] (assoc v :id k)) '{a {foo 0, bar 22}, b {foo 3, bar 44}})

16:21 clojurebot: ({foo 0, bar 22, :id a} {foo 3, bar 44, :id b})

16:22 benjyz1: cool

16:22 I always want to do a doseq... but I guess its always (map fn x)

16:23 justin_smith: benjyz1: doseq can only generate nil

16:23 benjyz1: sometimes I see into {} ...

16:23 amalloy: nil...and controversy!

16:23 justin_smith: ,(for [[k v] '{a {foo 0, bar 22}, b {foo 3, bar 44}}] (assoc v :id k)) ; benjyz1 alternate

16:23 clojurebot: ({foo 0, bar 22, :id a} {foo 3, bar 44, :id b})

16:24 benjyz1: hard to get rid of the habit of iterating

16:24 for each ... do stuff

16:24 amalloy: well, we iterate all the time

16:24 for each ... make stuff

16:25 (into {} (for ...)) is very common

16:25 justin_smith: right, but why do that when you are not even trying to create a hash-map

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