@smw: @cch1: binding will work.

newbie question, when i do (sort {:b 2 :a 1}) it returned ([:a 1] [:b 2]) in REPL, what is the data structure? why it didnt return {:a 1 :b 2}, if sort doesnt work in this way, why it sort the map but return a diff data structure?

@lumengxi: i am not sure but a map and a list are different things, map is not guaranteed to be in order

i guess you can not sort a map, that is IMHO sort converts the map to a list and gives you an ordered representation

@dbacar: thanks! it does look like that sort converts the map to a list, interesting

thanks!

please i am also a 4 year clojure newbie

dont take that info for granted

heh

@lumengxi: check out clojure.core/sorted-map

@bostonaholic: thanks! yea i found that func, was just curious why (sort {:a 1 :b 2}) would return something like that

@lumengxi: maps are seqs on their kv pairs, sort converts the input to a seq and then sorts.

hence you get a (sorted!) seq of kv pairs back

@arrdem: sorry, another newbie q: if map is already a seq, what do you mean by sort converts it into a seq again?

@lumengxi: sorry I was being imprecise. map is not a seq, but it can be converted to one. In this instance it is.

ha got it, thanks!

a seq is sort of similar to an iterator. so in order to sort the map '{:a 1 😛 2}' you need to traverse the elements

you'll see seq refered to as a "functional iteration protocol"

Good morning.

can you actually use 😛 in Clojure to mean :b? 😉

hello all. i'm interested in hugsql. http://www.hugsql.org . Is there any example how to do JOIN using hugsql?

@yogthos: Hello, Dmitry! I've read your article about hugsql? Can you tell where i can find example how to make JOIN using HugSQL?

@mike1452: hi, I guess you mean how to use table qualified keys?

@curtis.summers would probably have the answer for this one

@yogthos: thanx! (brief search by word JOIN did not return any useful results from docs) well, now i have a search direction

@mike1452: do you have an example of the query you’re trying to write?

@mike1452 A JOIN in HugSQL is just a JOIN in SQL. I guess I'm not exactly clear on the question, but I'm happy to help work through it.

How would I approach debugging c.t.namespace.repl/refresh? refresh wants to reload a CLJS namespace (in my CLJ code) even though the ns is never references, not on classpath. I also tried to set ctnr/set-refresh-dirs manually but the cljs macro file still gets picked up (and then "not found exception"). EDIT: Got it, inspected the #'refresh-tracker var and found out that it got picked up in resources (where cljs also compiles to). So I filtered resources|target directories from the classpath and did set-refresh-dirs and it works .

@stuartsierra: hey, in http://thinkrelevance.com/blog/2013/06/04/clojure-workflow-reloaded you’ve mentioned that “ring-devel is incompatible with tools.namespace”. As I understand - it currently is, and if I add wrap-reload to my ring stack - it would still work fine until: 1. dev.clj file (where the system is located) is changed. I guess the system will still work, as it would reference the objects, but I won’t be able to stop the currently running system. 2. components structure is changed and so the old components could miss some data? Am I right? And are those the only problems? Thanks in advance!

How can one take a string like "file.extension" and return ".extension"?

I.E.: How does one get the extension of a filename in clojure

See the extension function from this lib: https://github.com/Raynes/fs

bleh -- unfortunately I'm working in clojurescript

So can't use that

Perhaps I should ask in #C03S1L9DN

May need to write a regex for it.

Yea

improvising: (apply str (last (partition-by #{"."} "my.pdf")))

just tried in a REPL

but I'm sure it could be even simpler...

Nice

Even works for names like "double.dot.jpg"

yes, takes only the last portion after the "."

Is there any good way of working around having a protocol that does a conversion split across multiple namespaces when extended? I saw something like this argued in the past here: http://programming-puzzler.blogspot.com/2013/12/frustrations-with-namespaces-in-clojure.html While I disagree with a lot of what is written here and certainly don't support circular dependencies, in the case of protocols it makes sense to have a "merged" version. For example if I define in a "core" namespace conversions to/from various collection types, then in a more specific namespace I extend the same protocol to add in more specific conversions. As far as I know/have seen when the protocol is called and hits the "core" extend-protocol, it won't see the specific definitions. Thus it's not really possible to nest your conversions like that unless you put it all in 1 namespace.

@george.w.singer (let [[_ x] (re-find #"(\.[^\.]+)$" "file.extension")] x)

Is there a way to do a conditional assoc, which only associates the key, if the given value is truthy?

not in core, but you can take a look here: https://github.com/weavejester/medley/blob/master/src/medley/core.cljc#L25

wouldn't this just be something like (defn assoc-when [c k v] (if v (assoc c k v) c))?

seems to work for me

(how do I format code her in Slack?)

With backticks: code

ah.. let me try

Okay, we’ll I can’t show it, but you get the idea 😛

(defn assoc-when [c k v] (if v (assoc c k v) c)``

One backtick

ah

My mistake

(defn assoc-when [c k v] (if v (assoc c k v) c)

I was trying to escaping it

great - thanks!

I think my function is a correct solution

(it doesn't check for c being a mp though)

a map

forgot a parens, so:

(defn assoc-when [c k v] (if v (assoc c k v) c))

cool. looks good.

@swizzard: http://stackoverflow.com/a/7686324/3662110 or maybe approach it with :has

anyone using environ know if there is a way to “reload” configuration in a running repl session?

ive tried setting system properties (System/setProperty … …) but it doesnt seem pick it up

i had some luck with ns-unmap and redefining the env var, but that seems like a roundabout way

hey @jstokes environ tests remove and reloads the ns: https://github.com/weavejester/environ/blob/master/environ/test/environ/core_test.clj

hey great thanks @jonahbenton

hi, whats the correct way to use the logger? Like what kind of information do i log? do i log the result of my application?the arguments entered? my application is a text summariser

or if anybody could point me to a decent source regarding the conventions for what or when to log something, thank you

jstokes: Environ provides access to the process environment. You shouldn’t use it directly as a configuration.