I’m incorporating Integrant into a side project, and I’m wondering if it’s common to put all of the init-key and halt-key! multimethods in the same file, or if folks more often break up those declarations into multiple files and rely on side-effectful imports to ensure the system is composed properly?

Hi. Has anyone got suggestions for introductory hands-on Clojurescript material. Recent enough that it's not going to collapse in a muddle of broken dependencies and with enough context that you don't have to be thoroughly conversant with the modern JS ecosystem to know what's going on?

Looking for good learning resources for Clojurescript+Re-frame/Reagent!

What is the correct way to write tests for function which are defined using memoize .? Before testing a function, my test case would often like to erase the cache.

hi everyone, is there an open source project that uses datomic in extense where I could study its code?

Hi guys.I want to iterate over a nested vector and delete some elements (for example deletes "5" whenever finds it) and I want to use reduce / transducer instead of nested loop (unlike imperative systems). I do understand that the answer isnt nested loop recur. so i went for reduce/transdures but my code fails each time. Can u give me an example of doing so?

Trying to make start a repl this error. Run a project

Could not locate cognitect/rebl__init.class

full error

Caused by: .FileNotFoundException: Could not locate cognitect/rebl__init.class, cognitect/rebl.clj or cognitect/rebl.cljc on classpath.

What am I missing?

not sure what you're doing

what do you mean by "make rebl"

Trying to make start a repl this error. Run a project

the error is saying that you're trying to run rebl, but rebl is not on the classpath. but I'm not sure what you're doing so I don't know how to help

How do I add rebl to my class path than?

https://github.com/cognitect-labs/REBL-distro#usage is info on using clj to do this

there are some wiki pages with more info on other envs https://github.com/cognitect-labs/REBL-distro/wiki

Ahh, I see what the issue is. Thank you

Hi, I have been working with clojure fixtures. I am running a test and take a screenshot at the end, everything working fine. My question is, is there a way to get the name of the function in the fixture? I want to use it as the file name of the screenshot. Code:

(defn fixture-selenium
  [f]
  (try
    ;; setup here
    (f)
  (finally
    (println f) ;; Prints cider.nrepl.middleware.test$test_vars$fn__38755$fn__38760
    (save-screenshot)))

Currently whenever I add new query in queries.sql , I have to close and reopen REPL everytime to test it. I have also tried to reload in the REPL using (use '[demo.db.core :as db] :reload-all) but it didn't work. Currently I'm using Calva plugin in VS Code. So is there any way to test it without closing and reopening REPL everytime ?

I seem to recall a trick, discussed a while ago that involved some sort of compliation of the code during startup/repl? I can't recall. @alexmiller I think you mentioned it?

https://clojure.org/guides/dev_startup_time

wunderbar!

thank you dan 🙂

I'm still trying to figure out the purpose of dynamic variables when let exists

What is the use case here

dynamic vars let you pass context down the call stack but not as parameters

Oh so it's just dynamic scope then?

yes

generally, you should avoid dynamic variables imo - usually it's better to make that stuff explicit in the call

That's an ... interesting feature

dynamic variables are very powerful, but with power comes responsibility.

what is the right away to share global variables in clojure. e.g i have 3 different namespaces with ring routes and I want to pass db information

Another namespace with those variables ?

Don't make globals, pass arguments

A common way to pass extra stuff to ring handlers is middleware that assocs that stuff into the request map

so i'm using the environ library to hold db information

but not sure how to pass it to each route without calling it each time

I pass "configuration" as a map (usually I leave it the in last position, if a reasonable n-arity is required)

I also use juxt clip to manage some state, like a shared database connection, or a redis connection. That state is held in the map and passed around.

you guys tried aero ? I just noticed that I am not using leiningen profiles to decide which aero #profile to choose. I have (read-config "config.edn" (System/getenv "PROFILE")) ... someone knows if you can use the profiles passed as lein with-profile PROFILE and catch that value to be used in aero?

Yes, I use aero extensively

It's part of my juxt clip setup 🙂

But I don't use lein, I'm a deps guy 🙂

ouch =/ this app is a bit old now, I was happy with leiningen and decided to leave this way rsrs

Hi all! I am trying to understand how to use the component library from Stuart Sierra, but I am struggling to understand the record part. In the example, he creates a record using (defrecord Database), and then a constructor using map->Database. My doubt is: What exactly this map-> is doing? Is it mutating the Database record? How it was created? Thank you in advance!

@joao.micena When you use (defrecord Foo), Clojure automatically generates two constructor functions for you: map->Foo that accepts a regular hash map and returns a Foo record populated from the hash map and ->Foo that accepts positional parameters matching the fields you declared in defrecord (and returns a populated record).

Records -- like other Clojure data structures -- are immutable.

user=> (defrecord Foo [a b])
user.Foo
user=> (->Foo 1 "Two")
#user.Foo{:a 1, :b "Two"}
user=> (map->Foo {:a "One" :b 2})
#user.Foo{:a "One", :b 2}
user=> 

Hmmm I see, this helps a lot, thank you! By the way, I am also using your usermanager-example repo and it has been really helpful!