Hi, what is the simplest way to convert js/Date to goog.Date?

i’m using cljs.time if it helps

@pbaille: I read this the other day which might help: http://clojurescriptmadeeasy.com/blog/print-goog-datetime-as-inst.html

I’m aware it’s not a direct answer to your question but I thought it might help

yes i’m receiving a transit datastructure from the server containing #inst object, that became js/Date instance on the client

and I would like to turn it into goog.Date

am i suppose to convert it to string and parse the string with cljs.time in order to create goog.Date instance?

Is there something like react-refetch for ClojureScript? https://github.com/heroku/react-refetch

Calling map on side effecty functions doesn’t work, does it?

@urbanslug: works, but probably best to use run!

same signature

@anmonteiro: Thanks 🙂

Hmm why would this fail (map (fn) (fn-that-returns-a-map)) ??

Returns a map? Not a seq?

@urbanslug: you probably want (map fn (fn-that-returns-a-map))

if (fn) doesn’t return another function, that is

hard to know without seeing it

well it’s really (map #(…) (fn-that…))

care to post a minimal case of what’s not working for you?

Let me try to.

So the anonymous function is going to get a vector containing a key/value pair, is that what it’s expecting?

No it’s going to get a list

hmm I guess I was doing something like (fn [n] (prn n))

should work too

You might want something like (map (fn [[k v]] (do-something-with k v)) (fn-that-returns-a-map)), so your keys and values get destructured into separate args

hmmm think I see the issue. map returns a sequence (lazy) but takes a collection is there a difference between this? There has to be. Also I’ll force a vector with (vec (map…))

@urbanslug: my preferred approach is to use into with a transducer

e.g.: (into [] (map fn) coll)

whenever I want a vector out, that is

(vec (map ...)) and (into [] (map fn) coll) is also equivalent to (mapv ...)

arkh: Nice I didn’t know about (mapv …)

(into ...) is more generally applicable but (mapv ..) is more succinct

(let [keys (into [] (map #(str "ba" %) ["br" "bro"]))]
  (println “br”)
  (map #(println %) keys))

br prints but second one doesn't

map is lazy so it needs to be realized

Ah!

bloody!

I knew this had to do with laziness!

more like had a hunch

in your code above, you'll notice that it doesn't print anything but it will return a LazySeq

and that LazySeq is map 'ready' to run your function over its collection

@arkh: Thanks a ton it makes sense

doseq ftw

hello, i've come uppon this particular code in om next and having a hard time figuring what .. means

(om/set-query! ac
  {:params {:query (.. e -target -value)}})

I can see it applies the event to those arguments but i cant see how the - and e works with it

and macroexpand dont seems to work

the .. is a macro built into Clojure. Its basically method chaining in javascript i.e. e.target.value

yeah i could see. but why is it so funky

you have to use (.-propName obj) syntax for properties in cljs

oh so its in clojure? I've searched the docs and couldnt find anything

yeah, but you don’t see it as often with Java interop in my experience because you are rarely grabbing instance properties (usually just grab methods or static members): http://clojure.org/reference/java_interop

Hi all, I am experiencing a really strange clojurescript bug.

I’ve created a repo explaining it here: https://github.com/ducky427/cljs-bug

essentially a map I am getting back from converting an edn string to a map using cljs.reader/read-string isn’t behaving like a map at all

and this weirdness only occurs under some very very particular circumstances

I’ve been able to able to narrow it down to as little user code as possible.

and its possible to reproduce it without the use of lein or boot or any library

Any help would be really appreciated. A co-worker and I have spent better part of 2 days to figure it out and are completely lost now

@rohit: good job at shrinking down the example, probably you can drop it in #C07UQ678E as well

@richiardiandrea: thanks. will do.

Or open a jira ticket directly

I’ll do that as well. I thought if someone can identify the actual issue, then its worth creating a jira issue.

Yeah well it looks like part of the reader, but I will leave the scene to core devs ;)

just wanted to verify it here on my machine but https://gist.github.com/darwin/02923ab43978f24389d6faf464f14fe4

I’m not sure how to run it, java noob here, have been happily living with lein for 1+ yrs

lol. ok let me also create a project.clj for it

I many times had strange behaviours with disparate node versions, especially regarding IO...in replumb I stick with 0.12.7 for now...

just pushed a project.clj file

lein cljsbuild once dev and then node main.js should get you to the error

@darwin: figured out why it didn’t work the first time around - i hadn’t committed the .jar file. d'oh

its done now

yep, does not work here: https://gist.github.com/darwin/407b51ba569524c0a95bd651f1059fb5

have to go...

cool. glad you were able to reproduce it

@rohit might be helpful if you start reducing the values in the edn file you have, just to narrow it down. When I run it with empty values

{:pnodes []
 :settings {:monitor false, :validation false},
 :sdata {}
 :data-files #{ },
 :version "1.5"}

java -cp cljs.jar:src clojure.main node.clj
node main.js
(:settings :sdata :data-files :pnodes :version)
1.5
:version key is present

@peterschwarz: thing is if i do that, it works as expected

so its something about the size

Maybe not size, but perhaps something in the data? It's not really a huge string...

it almost feels like (in a very unscientific) the large datastructures somehow push cljs over a limit of some sort.

@peterschwarz: not really. have a look at https://github.com/ducky427/cljs-bug#how-to-mitigate-the-error

so just commenting out some code, makes the program work as expected

so it isn’t just the data

I arrived on how to get rid of the error by just trial and error.

and it makes no sense to me

That's weird

@rohit another idea would be to check what the code compiles (transpiles sorry) to and try to execute it in node or even some JavaScript engine, maybe you've done that already

i’ve done that already. i could create a browser based test but then it would require a remote call to get the data

let me see if i can embed that string into a cljs file safely

Just to check if it is cljs on node only

Remote call: https://github.com/Lambda-X/replumb/blob/master/src/browser/replumb/browser/io.cljs

i’ve got the code translated for the browser as well here: https://github.com/ducky427/cljs-bug-browser

still the exact same behaviour

great this is more likely to be a Cljs bug then

the bug feels like its in when the cljs.core/PersistentHashMap datastructure is being created

if i make the result a cljs.core/PersistentArrayMap, it behaves as it should.

after the read-string?

yup

the read-string returns a cljs.core/PersistentHashMap

i convert it to a cljs.core/PersistentArrayMap and it all works

odd

array-map has just a performance improvement over hash-maps for small maps

so an implementation detail

the behaviour is supposed to be exactly the same

what if you try tools.reader there?

yes but it is probably copying it over

[org.clojure/tools.reader "1.0.0-beta1"]

let me try that

[clojure.tools.reader :as reader]

its [cljs.tools.reader :as reader] it seems

nope it has the same behaviour

😖

well, I would then report all these results in #C07UQ678E and maybe open a JIRA ticket

@richiardiandrea: thanks for the help.

gonna call it a night now.

I wish I could have helped more 😉

its fine.

really appreciate it

no problem