👋 I’m here! What’d I miss?

May I ask here questions about cljs?

I have some functions here, I dunno how to compose in a map like structure....

I want to send-image-to-contacts! to work, some tip ?

@d.ian.b I'm not entirely clear what you're trying to do, but I suspect that #core-async might be a good place to ask, or #clojurescript ?

thanks!

I want to iterate send-image-to-contact! onto the contacts vector

on main

and the send-image-to-contacts! is not working

does clojure have association lists like common lisp does?

@radicalmatt Clojure has first class associative data structures: hash maps.

is there a standard clojure documentation system which I should use if I'd like to release a library to the public?

How do I transform this?:

({:s "a"
  :t [1 2]
  :l [3 4]}
 {:t [5 6]
  :l [7 8]})

{:s "a"
 :t [1 2 5 6]
 :l [3 4 7 8]}

looks like a reduce concat keys

Thanks for the replay, I played around with those functions a little but still no luck

@rickheere (apply merge-with (comp flatten vector) a)

quite interesting

(apply merge-with vector a)
{:s "a", :t [[1 2] [5 6]], :l [[3 4] [7 8]]}

(apply merge-with concat a)

Ah, very good. {:s "a", :t (1 2 5 6), :l (3 4 7 8)} is what I get from

(def a '({:s "a"
         :t [1 2]
         :l [3 4]}
        {:t [5 6]
         :l [7 8]}))

(comment
  (apply merge-with (comp flatten vector) a))

(apply merge-with concat a) +1

nice

I think that is good enough for now. Thanks @delaguardo and @danieltanfh95!

If you care about list versus vector in the result, you can replace concat with your own hand-written function that checks for list vs. vector, etc.

(apply merge-with (comp vec concat) a) works as well

I managed to get it to work with this as well

(apply merge-with (fn 
                      [a b] 
                      (into [] (concat a b))) a)

and yes (apply merge-with (comp vec concat) a) also work, probably better.

Thanks everyone.

Does anyone have an idiomatic way to test if a vector is sorted? I've got a predicate using destructuring and recur and I don't like it very much.

depending on the size you could just do (= c (sort c)) where c is your vector or collection

@radicalmatt If all the items in the vector are numbers, I guess you could also try (apply <= c)?

@dpsutton That was my first thought too, but, then you can just sort the vector and know that it's sorted, saving an equals on the whole vec

If the true / false test of a <= b is some other function cmp, then something like (every? (map cmp (partition 2 1 coll))) would work

If it comes from outside your application I would say you have to sort it yourself to be sure. If it's your own code, maybe it's possible to write some static analysis?

Not at a repl to test that right now — it is probably at least slightly wrong

the test of a collection being sorted does not require sorting it to be sure

Yea, thats true and finding out it's not sorted is probably faster than sorting it.

wow how did I miss apply

sean strikes again

I would probably do something like this to verify if not sorted, then resume

(reduce
 (fn [acc v]
   (if (<= acc v)
     v
     (reduced false)))
 a)

hm I didn't know about reduced either

What’s a good approach for printing the stack frames of a function call in Clojure? I would like to see the entire stack trace including the 3rd party libraries that my function is calling.

@tkjone At any given point you can try & catch an exception and get the stack elements from the exception object: there's a function Throwable->map in Clojure that will turn the object into Clojure data.

But you can only get at the stack from where you are in the call tree -- you wouldn't able to see down into 3rd party code below your current execution point.

Thanks, Sean! So the only way to trace, for example, a 3rd party library, I would have to clone said library and run the trace through that library. In general, i’m researching how a library works and I want to see all the function calls being made to get a high level overview of the code paths.

kind of like of you can do this with console.trace in cljs/js

@tkjone You may find https://github.com/clojure/tools.trace/ helpful for that (as long as the 3rd party libs are all Clojure).