@adamkowalski It might be enough to implement the few interfaces mentioned here: https://clojure.org/reference/data_structures Until a better, more accurate advice comes along, you can study some of Zach Tellman's implementations: https://github.com/ztellman/clj-radix/blob/master/src/clj_radix.clj https://github.com/ztellman/clj-tuple/blob/master/src/clojure/lang/PersistentUnrolledMap.java Or this example: https://gist.github.com/david-mcneil/1684980

what do you do when u cant load namespace

CompilerException java.lang.Exception: namespace 'picture-gallery.routes.auth' not found, compiling:(cider-repl picture-gallery:51:7)

@lepistane when does this happen? If you try to eval buffer in Emacs?

well i am reading book WebDev with Clj 2nd edition and i am at chapter 8 making picture-gallery we are supposed to make authentication so i made new file auth.clj in routes folder and tried to test register user function i made but i cant it get that error i used cider-browser-ns and i cant see routes.auth namespace why is that?

try to eval auth namespace first

to double check you can always lein run, lein test, or lein repl to make sure that there are no errors

i did nothing changed, i tried to restart server to save files nothing

lein repl doesnt recognise the auth NS i created

hm, that's strange. Are you sure that you created the namespace in a proper directory? I'm just looking at picture-gallery-a from book's code examples and the namespace is "picture-gallery.routes.services.auth" (with "service") but it really doesn't matter much

i didnt get that part

so i just put auth in routes folder

because services is a file that has namespace

not a folder

yea that's what i thought. it shouldnt matter

just to make it clear: - in the book the file structure is as follows: src/clj/picture-gallery/routes/services/auth.clj -> you should declare namespace picture-gallery.routes.services.auth in this case - if you created file src/clj/picture-gallery/routes/auth.clj then you should declare namespace picture-gallery.routes.auth and be able to use it

k i am blind

error in process filter wrong type argument characterp nil getting this error while evaluating NS

Hey I want something like "1245" that I want to make "12:45"

I'm thinking of using regex

Not sure but the point is insert colon as the 3rd last char in string

@urbanslug not sure about elegance but something like take (let [s "1245"] (apply str (first s) (second s) ":" (rest s))) might work i am sure there are bugs or things u have to fix but that's my idea

@lepistane Yeah not too elegant (clojure.string/replace "1234" #"..$" #(str %1)) I have this which is close

I just need to find a way to add the colon

(clojure.string/replace "1234" #"..$" #(str ":" %1))

@lepistane LOL phantom js says "undefined is not a constructor" even thought I've used the function just above this use. 🙂 will try your way. clj to cljs fails

take 2

@urbanslug No need to use replace when substing is enough.

substring?

Yes, substring. Typo.

i made it work!! how? well bottom up approach function was making error so it couldnt load NS tnx for help everyone

(macro-expand-1 '(defn-with-defaults foobar {:inc 1} [deps b] (+ (:inc deps) b))
-->
(defn foobar
  ([b] (foobar {:inc 1} b))
  ([deps b] (let [deps (merge {:inc 1} deps)] (+ (:inc deps) b))))

I'm trying to write that kind of macro

I'm new to writing macros, but I think I'd need a macro that captures a variable on purpose (so it can add that overwriting let expression), but I also need splicing-unquote, which I think is only available when syntax quoting

but syntax quoting doesn't let me capture variables

(defmacro defn-with-defaults
  [name defaults params & body]
  `(defn ~name
    (~(vec (rest params)) (~name ~defaults ~@(rest params)))
    (~params (let [deps (merge ~defaults ~(first params))]
               ~@body))))

So this wouldn't work..

kauko ~‘foo allows variable capture

So keep that as it is, but (let [~'deps ..?

actually, I think what you want here is gensym

~‘deps should work, but I don’t think it is a good idea to write macros with magic variables like this

gimmie a sec

(defn-with-defaults increase {:inc 1} [deps a] (+ (:inc deps) a))
=> #'clojure.core/increase
(increase 1)
=> 2
(increase {:inc 5} 1)
=> 6

Nevermind the clojure.core namespace, I accidentally switched to that namespace instead of my own core ns when trying this out in the REPL 😄

But that is what I want. Just imagine the function actually does something sensible, and gets for example a db connection in the deps parameter

I don't think gensym helps me here, because the way I understand this is I need to have that let block in the function body

and it wouldn't do much if it was deps# instead of deps

here’s the problem:

kleinheit.extractor=> (macroexpand-1 '(defn-with-defaults foobar {:inc 1} [something b] (+ (:inc something) b)))
(clojure.core/defn foobar ([b] (foobar {:inc 1} b)) ([something b] (clojure.core/let [deps (clojure.core/merge {:inc 1} something)] (+ (:inc something) b))))

[something b] looks like a parameter list, but it doesn’t function the same way

which will be very confusing a couple of weeks later

Yeah, I actually realised that. I'd be fine with it. Do you have any ideas how to avoid that though?

(I deleted some messages). I guess it would be better if the let-binding bound to the same symbol as the first parameter

quick repl question!. why can't i see the gen namespace in this scenario? if i lein repl then (use 'ms.specs) and then try to call gen i get Unable to resolve symbol: gen in this context:

(ns ms.specs
  (:require [clojure.spec :as s]
            [clojure.spec.gen :as gen]))

kauko yeah

but IMO macros like these tend to be more trouble than they’re worth

I’d just type it out 🙂

Haha could be, I'm just learning 🙂

It's a personal project, I'm allowed to be cute dangit! 😄

for that purpose it’s completely fine 👍

first you should know how to to it, and then you should know when not to do it 😄

😄

I wonder if it's even possible to get this to work with destructuring though

I guess I can access the :as definition like from a map.. and make the macro fail if there is none? I dunno

I don't seem to be doing this right. Does anyone know how to invoke the playbackRate method?

#?(:cljs (.playbackRate (. js/document (getElementById "my-video")) 0.6))

Are you using React (Reagent, Rum...)? If yes, getElementById probably doesn't work.

Have you made sure the code is actually finding and returning the element?

I am using Rum

If I get the component how to do the function on it

Don't know off the top of my head. That looks pretty close. You probably need to use a built-in function in Rum to access the React component, then call .playbackRate on it 🙂

I'm sure you can get help at #rum. I see you've already asked other questions there :thumbsup:

Was just trying to not flood it with nooby questions haha

Hehe 🙂

@kauko is there a standard way to set a property in Rum/Reagent etc?

@joshkh: because namespaces are not seen as objects. So gen will not work but gen/vector will.

user=> (require '[clojure.spec.gen :as gen])
nil
user=> gen

             java.lang.RuntimeException: Unable to resolve symbol: gen in this context
clojure.lang.Compiler$CompilerException: java.lang.RuntimeException: Unable to resolve symbol: gen in this context, compiling:(/tmp/form-init7595209781886275963.clj:1:8637)
user=> gen/any
#<Fn@10f353c7 clojure.spec.gen/eval31156[any]>

thanks @not-raspberry

is anyone here good with spec? 🙂 i've used gen/generate to create bunch of maps with UUIDs and i'd like to generate (using spec) vectors containing those UUIDs.

#clojure-spec

ha, thanks again

Does anyone know if there is an equivalent to python's newspaper library in clojure? It looks like enlive might be the right place for me to look (https://github.com/swannodette/enlive-tutorial). Are there others?