I feel like im missing something that would explain this behaviour

(satisfies? B "foo")

yep that was it

(extends? B String)

thanks

How does the special form var resolve private symbols? Is something else used for resolving symbols that are used directly?

var resolves everything you give to it, including private symbols.

I have an old project that has a transitive dependency (via Immutant) that seems to have disappeared from the internet in the past few days: org.projectodd:polyglot-cache:jar:1.20.0

looks like it may have been hosted at https://repository-projectodd.forge.cloudbees.com/release which is now 404 ... anyone else seen this?

@taylor I used to work on Immutant. I'll ping my old team to see if that cloudbees account has been shut down

cloudbees just eol’ed some of their products this past weekend

I'm pondering the use of single-segment namespaces. In general, I know they are to be avoided. But as I'm moving to ns-qualified keys in all my data structures and as I'd like to use the :: reader syntax sugar, the keys in my data structures must correspond to namespaces. And I'm beginning to worry about the overhead — many extra characters per key are being stored in a database, exported, imported, moved over the wire, etc. I came here to listen for sage advice on the subject.

Is it possible to invoke the clj CLI with multiple -m args?

no

it’s possible to run a .clj script though that does anything you want

Did anything change between 1.10-RC5 and 1.10?

nope

Excellent thank you

@jrychter both type of namespaces have separate concerns in my experience: whereas a ‘code namespace’ should never clash with any other library, data namespaces mostly don’t need that: {:video/id "YR5WdGrpoug"} is better than {:id "YR5WdGrpoug"}. I’ve also heard experiences that using :: turns renaming a namespace into a nightmare.

there are a lot of assumptions in the question about how data is going to be stored and transported as well

We’ve been using 1.10 in production for sometime now with the cognitect/aws-api and it’s been working great so far. Solved some illegal reflective access warnings on our upgrade to Java 11 from 8. Only thing that we had to change in our code were Java import statements (:import [java.util Date])) instead of (:import [java.util.Date]))

the "overhead" of keys in a database is largely going to depend on your database choice, and if you storing blobs of data in the database, or actually storing data in a way that the database can see

a sql database for example, usually already provides facilities for namespacing names (tables, schemas, etc)

(on top of the fact, of course, that sql databases don't store column names repeatedly like that anyway)

The overhead gets accumulated all over the place, and I'm beginning to get worried. Think of things like memory consumption on the ClojureScript side. It can be mitigated in some places (transit helps on the wire, for example), but overall it feels silly to add additional 9 characters to every key everywhere, unless there is a very good reason.

keywords(in clojure, and likely in clojurescript) are interned

@eval2020 Hmm, I'm not sure if using separate data namespaces is practical. I'd need to try it to be sure, but all spec examples assume your code namespaces correspond to your data namespaces and use the :: syntax.

:x/f is always an identical object to :x/f regardless of the source

using :: in examples is strictly to keep examples short, not because it is good practice

Hmm. The renaming effort is huge anyway, so I guess I might as well use separate "fictional" data namespaces and stop using the :: notation...

@jrychter with spec you can run into circular references pretty easily: https://old.reddit.com/r/Clojure/comments/8ousfs/namespaced_keywords_question/

@eval2020 Yes, I did run into that. In most cases it turned out to be a signal for the need for code refactoring, but in certain cases it's unresolvable.

not only is it not required for keyword namespace names to match code namespace names, I think it is bad for them to do so

e.g. you don't name a database table after the code that touches it

data is data independent of the code that manipulates it

Right — but you lose the slightly nicer syntax, then. But I guess it's a reasonable price to pay.

the nicer syntax leads to brittle code too

you copy and paste code from one namespace to another then boom

I agree with hiredman: detach data ns-es from code.

Thank you for your time and advice — I am now looking at this closely and trying it out. Well, trying will take 2-3 days with the size of my codebase.

What's the landscape look like in 2018 if I want to develop a REST API using spec? I've seen compojure-api but are there any other libraries?

BTW, it doesn't have to be ring/compojure based

@trevor check out https://github.com/metosin/reitit. Works with ring, pedestal/interceptors and frontend.

How would one transform the string "#'user/msg" to the unevaluated literal #'user/msg?

(read-string "#'user/msg") -> (var user/msg) which is not quite what I want

your repl is just being weird

(var user/msg) is a synonym for #'user/msg

(I assum you meant var there not val)

hrmm

oh

you are using clojure.edn/read-string

(nope)

and the synonym of var and #' is only after evaluation

Wait sorry, this is a moot problem now. The issue corrects itself when switching from nrepl “0.4.5” to “0.5.3". 😓

I use clojars in emacs to find deps ( M-x clojars), sometimes, but don't always find what I'm looking for... in the current moment clojure.java.jdbc... are any of you able to pull it up that way... is there a better approach? I might be misusing the package... dunno.

I found https://github.com/clojure/java.jdbc on the web.

all of the clojure contrib libraries are deployed to Maven Central, not Clojars

ah ok... so is there a way to find them from emacs? got used to the M-x clojars approach... or... how do you do it?

I also have seen several tools for adding the most recent dep version numbers if you type type the base name into your project.clj... but I usually get mixed up about when to use dot and / separators and have to look them up. #maybe-being-just-too-lazy

ok... the maven central site is pretty slick... that will work (although something from an editor would rock).

I feel like it would be great if we had an npm style tool you could search and add things to project.clj... as it is I flounder around on clojars, maven, etc and am never sure if I have a current version or not and it's a bit of a buzzkill when you're trying out deps. I'm sure it's all part of the adaptability of clojure which I may need to understand more.

I remember lein plz... I'll give that a go.

there’s also ataraxy if you like data-driven routing

https://github.com/weavejester/ataraxy

Hi guys! I comming back to clojure and I would like to know if is there a good alternative to Intelij IDE?

many people are happy with emacs + CIDER or VS code + calva, in addition to the cursive plugin for Intellij

@alexmiller fyi, these still point to clojure 1.9 https://clojure.org/guides/getting_started#_installation_on_linux

I’m still working on the 1.10 clj release

technically, you can use any Clojure version, including 1.10, with the current version of clj, so it’s not really that important - it just affects your default if you don’t have a deps.edn

ok, I was just about to update our docker images where we use the linux installer to install the default version and noticed this

updated

brew pr is still pending for mac

thank you, much appreciated

Awesome, thanks!

Hi - my understanding is that Clojure 1.10 has been released. Does a release apply to brew upgrade clojure on a mac?

$ brew upgrade clojure
Error: clojure 1.9.0.397 already installed

@aaelony from above. it is pending

ah - thank-you.

you don’t need an updated brew formula to use 1.10 though

understood

just add org.clojure/clojure {:mvn/version "1.10.0"} to your deps.edn to use it

pr is https://github.com/Homebrew/homebrew-core/pull/35199 - brew prs seem to be backed up at the moment

often takes 12-24 hrs to go through anyways

related question… I’m am very familiar with lein new myproject but about to try the deps.edn approach for the first time. Is https://clojure.org/guides/deps_and_cli the best resource? Is there a tool that does something analogous to lein new myproject?

there is

many deps tools at https://github.com/clojure/tools.deps.alpha/wiki/Tools

specifically clj-new

https://github.com/seancorfield/clj-new

awesome, I’ll read through it. Thank-you

although the “template” for a deps.edn project involves almost nothing, so I do not find it to be necessary

my goal is to migrate off an amazonica project to com.cognitect.aws… I haven’t experimented with deps.edn before however

cool, feel free to ask questions in #aws if you get stuck - David watches that

excellent. thanks

should

clj -Sdeps '{:deps
              {seancorfield/clj-new
                {:mvn/version "0.5.5"}}}' \
  -m clj-new.create \
  app \
  myname/myapp 

@aaelony It should just work, yes:

(! 507)-> mkdir aaelony

Mon Dec 17 15:17:08
(sean)-(jobs:0)-(~/clojure)
(! 508)-> cd aaelony/

Mon Dec 17 15:17:10
(sean)-(jobs:0)-(~/clojure/aaelony)
(! 509)-> clj -Sdeps '{:deps
>               {seancorfield/clj-new
>                 {:mvn/version "0.5.5"}}}' \
>   -m clj-new.create \
>   app \
>   myname/myapp 
Downloading: seancorfield/clj-new/0.5.5/clj-new-0.5.5.pom from 
Downloading: seancorfield/clj-new/0.5.5/clj-new-0.5.5.jar from 
Generating a project called myapp based on the 'app' template.

@seancorfield, I filed a ticket. It doesn’t work as above for me

I don't know if it matters, but you have backslash at the end of most of the lines, but not the first two

As of yet, there is no means to attach rebel-readline to an nrepl server right?

attaching it to an nrepl server doesn't make sense

@andy.fingerhut - I literally just copy pasted the example from the “Getting Started” part of the readme

all in one line doesn’t appear to help

What does anyone think about this?

user=> (defn send-rockets! [] (println "BOOM!"))
#'user/send-rockets!
user=> (comment {:a} (send-rockets!))
Syntax error reading source at (REPL:1:14).
Map literal must contain an even number of forms
BOOM!
nil
Syntax error reading source at (REPL:1:31).
Unmatched delimiter: )

that behavior will depend on your repl

but in generally it is going to be hard to define a repl that does the right thing there

what repl are you using?

Figured as much. Would you say that such behavior is not set in stone, and custom REPLs are free to choose different behavior in such case?

yes

that behavior is due to treating the input as a stream

This works the same in clj, rebel-readline, and nREPL

I am surprised that it does that in nrepl, what nrepl client?

but basically, because the input is malformed, it isn't like there is an easy way to determine where the malformed "form" ends

so it isn't like you can just skip past it in the stream

CIDER, but I guess that doesn't depend on the client, it seems like a default "eval" op behavior

it would depend on the nrepl client

because nrepl isn't stream based

Yep, so the form is sent in one message wholesale

hrrm, yeah, even from nrepl it would be tricky

the "right" thing there would be to skip all that input, but doing that is tricky

because the case for processing input is like a combination of completed form and newline

What's even more jarring is that this makes it harder to debug a stray odd-element map in the code since the actual cause gets obscured by totally weird and unrelated errors.

so don't use (comment ...)

and don't have top level effects

comment was just an example how a syntax error causes Clojure REPL to go execute things it had no business executing at that particular invocation; and it also produces alien error messages.

(defn foo [a b]
  (let [c {:a a :bb}]
    (println "Inside defn, why would I be called during compilation?")
    c))

             clojure.lang.ExceptionInfo: 
clojure.lang.LispReader$ReaderException: java.lang.RuntimeException: Map literal must contain an even number of forms
             java.lang.RuntimeException: Map literal must contain an even number of forms
             clojure.lang.ExceptionInfo: 
clojure.lang.LispReader$ReaderException: java.lang.RuntimeException: Unmatched delimiter: ]
             java.lang.RuntimeException: Unmatched delimiter: ]
Inside defn, why would I be called during compilation?
clojure.lang.Compiler$CompilerException: Syntax error compiling at (script.clj:246:1).
             java.lang.RuntimeException: Unable to resolve symbol: c in this context
             clojure.lang.ExceptionInfo: 
clojure.lang.LispReader$ReaderException: java.lang.RuntimeException: Unmatched delimiter: )
             java.lang.RuntimeException: Unmatched delimiter: )
             clojure.lang.ExceptionInfo: 
clojure.lang.LispReader$ReaderException: java.lang.RuntimeException: Unmatched delimiter: )
             java.lang.RuntimeException: Unmatched delimiter: )

I get how this is a limitation of stream-based REPLs, but in the different case I'd say this should be avoided.

it didnt evaluate it, it parsed it

use ; comments if you dont want it to be parsed

> Inside defn, why would I be called during compilation?

it is a parse error, not a compile error

it is an invalid s expression in clojure

... which means it's perfectly reasonable to execute random parts of that invalid S-expression? I don't get what you trying to say.

it is not being executed, it is being read

REPL stands for Read Eval Print Loop. This is Read phase

it is being executed

No, it is being executed, because println triggers.

what is happening is the parser throws an error

the error is reported

then the repl goes back to the top of the repl loop

and reads from the input stream again

oh, isee, that is wild, i am wrong

and the input stream's state is pointing at to the place just after where the error occurred

but a strategy to pass over malformed input is really hard, because by definition it is malformed

File a ticket if you want

No, don’t as this isn’t going change

@alexmiller Yup, I get that. Just trying to figure out if it makes sense to try to push such change to nREPL since it's message-oriented, and it seems easier to skip over the invalid input there.

Thanks for everyone's response, I will brew it in my head for a while longer.