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#babashka
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2021-02-11
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Daniel Stephens13:02:09

Hi all, is there a way to get babshka to automatically handle logging of data from an ExceptionInfo exception or do I need to catch and log them myself? Some code:

(def some-map {:a 1 :b 2 :c 3})




(throw (ex-info "ABC" some-map))
The output (no mention of contents of some-map):
----- Error --------------------------------------------------------------------
Type:     clojure.lang.ExceptionInfo
Message:  ABC
Location: /home/dstephens/git/ccm/ui/i18n/./translate.clj:249:1

----- Context ------------------------------------------------------------------
245: 
246: 
247: 
248: 
249: (throw (ex-info "ABC" some-map))
     ^--- ABC

borkdude13:02:14

hmm, I think the error output could be made nicer showing the contents of the ex-data

borkdude13:02:25

feel free to post an issue (and optionally a PR)

👍 4
borkdude13:02:09

I'm thinking something like this:

Type:     clojure.lang.ExceptionInfo
Message:  ABC
Data: ....
maybe?

Daniel Stephens13:02:25

okay cool, I've been meaning to understanding how babashka actually works for a while so I'll have a look. Yeah, that's sort of what I was expecting to see

borkdude13:02:35

We could also support:

(Thread/setDefaultUncaughtExceptionHandler
 (reify Thread$UncaughtExceptionHandler
   (uncaughtException [_ thread ex]
     (log/error ex "Uncaught exception on" (.getName thread)))))
This is currently not possible, but we could make it work.

borkdude13:02:48

feel free to post another issue about that too

borkdude13:02:30

maybe a nicer API like (set-default-uncaught-exception-handler! ...) in babashka.utils or whatever could also work

borkdude13:02:07

Let's first add the ex-data to the error output

Daniel Stephens13:02:53

I raised https://github.com/babashka/babashka/issues/730 for the ex-data, hope I've captured enough.

borkdude13:02:58

yeah, babashka already has a datascript feature flag :)

jeroenvandijk13:02:11

ah ok cool. Missed that 😅

jeroenvandijk13:02:29

• I was misled by this comment Datascript does not compile at all when using clojure 1.10.

jeroenvandijk13:02:39

In the other graalvm-clojure repo

borkdude13:02:44

are there any recent improvements for this btw? last time I tried it, it really took a long time and the binary was huge

jeroenvandijk14:02:15

du -h target/datascript
 28M	target/datascript
Didn’t take too long

jeroenvandijk14:02:43

maybe it is because of the reflect-config trick. Could be made smaller i guess

borkdude14:02:44

ok, maybe try again then by updating the feature flag. @jeroenvandijk have you seen this btw? https://yyhh.org/blog/2021/02/writing-c-code-in-javaclojure-graalvm-specific-programming/ a durable datascript, we can make a pod out of this

jeroenvandijk14:02:36

ah no i haven’t. Will check it out

jeroenvandijk14:02:41

Really cool that it’s posssible. Will stay away from C myself for now 😅

borkdude14:02:08

yes. soon we will have a sqlite-ish pod but then based on datalog, how cool :)

borkdude14:02:06

the author is now working in a CLI version first. maybe, if he's open to it, I can add pod support to that

jeroenvandijk14:02:42

Super nice 🙂

holmdunc21:02:58

for babashka.fs , is there some criteria for what to implement, and what not to implement, from the inspiration libs?

borkdude21:02:28

@duncan540 dunno - what do you have in mind?

holmdunc21:02:02

Something like expanding ~ in path strings to the home directory, I guess is a shell thing and not a Java thing. Handy though

borkdude21:02:41

yeah, I think such things could be handy, but I've never personally needed it. can you give an example when one would need this in a clojure program?

borkdude21:02:35

by not having this, people will maybe write more cross-OS friendly code, like (fs/path (System/getProperty "user.home"))

holmdunc21:02:47

If I write some script for a personal automation task, I don't want to hardcode my username in the script

borkdude21:02:42

$ bb -e '(System/getProperty "user.home")'
"/Users/borkdude"

holmdunc21:02:33

yep that works. I guess it's just a question of how much of a "light touch" writing Bash-style scripts in bb aims to have

borkdude21:02:57

I think adding a home function that does the above is still good

borkdude21:02:07

since not all people might know how this works in Clojure / JVM

holmdunc21:02:19

I remember we talked about a "light" way too have the equivalent of Bash set -e mode, and you came up with this nice macro:

(defmacro $$
  [& args]
  `(let [proc ^{:inherit true :dir fs/*cwd*} (child/$ [email protected])]
     (child/check proc)
     nil))

holmdunc21:02:22

The clj-commons/fs library has (fs/expand-home "~/path/to/something"). That's like Python's os.path.expanduser("~/path/to/something") and obviously it just happens natively in Bash

borkdude21:02:49

and this should also work on Windows while "~" isn't a thing there? why not just (fs/path (fs/home) "foo" "bar")? This is even more preferable than writing hard-coded file separators

borkdude21:02:34

maybe a function that will parse a unix shell path to a normal fs path could be nice though. So ~/path/to/something will even work on Windows

borkdude21:02:55

(I'm thinking out loud as you can tell)

holmdunc21:02:32

yep that true, writing paths as a single string is just a hard habit to break after writing a ton of Bash over the years

borkdude21:02:26

This is number one: https://github.com/babashka/fs/issues/12 The other one needs more hammock time maybe. Is ~ the only thing to expand? Are there other things that need expansion? Env vars?

holmdunc21:02:43

The deluxe version of ~ that I have a hunch hardly anyone knows exists is that you can put another user's name after the tilde. So ~alice/path/to/something. Env vars would certainly be useful for writing Bash style scripts. I haven't personally noticed the lack of them though. ~ is equivalent to ${HOME} I guess.

borkdude21:02:06

I'll just make an issue about this and then we'll think about it some more. People can react there so we can see if more people want this. My hunch currently is that this is fairly easy to do using a custom defined function

holmdunc21:02:36

Cool - thank you for considering it!

thumbnail22:02:55

Hey 👋:skin-tone-2: I'm looking to run cljfmt in babashka; which needs rewrite-clj. Replacing it with rewrite-cljc didn't work because it relies on clojure.lang.IMeta . Has anyone walked this path before 😬 ?

borkdude22:02:25

I don't think that path will work, since you will also have to run all of tools.reader, etc inside babashka. Even if this would work, I don't think it would perform as good as in clojure itself, which kind of misses the purpose of using babashka for good startup time.

3
borkdude22:02:39

Having said that, there is a cljfmt binary I think? There is also a zprint binary and the zprint binary uses sci (the same interpreter that bb uses) for configuring certain things using functions.

borkdude22:02:23

But if there is a good use case to add clojure.lang.IMeta, you can convince me to add it

thumbnail22:02:00

Thanks for the pointers. I am looking to integrate a couple of formatters in a single point of entry. But since the process will take several seconds; I might not win much by using babashka here over a lean clj project :thinking_face:

mynomoto13:02:41

Besides the alternatives already suggested I would recommend https://github.com/greglook/cljstyle that has a native binary and works mostly like cljfmt with more knobs.

3
borkdude22:02:50

Exactly. If the program already takes a few seconds in an already started JVM (with all the namespaces already loaded), it's probably better to just run it on the JVM

3
borkdude22:02:49

And if you want to optimize startup time for all of these formatters, you can compile this into a GraalVM binary later on

thumbnail22:02:33

This makes sense :thumbsup::skin-tone-2: Haven't played with Graal on a first hand but this seems like a good moment 🙂

borkdude22:02:06

https://github.com/lread/clj-graal-docs is a good place to start, also the #graalvm channel

thumbnail22:02:36

Thanks, appreciate the help

holmdunc22:02:58

zprint is an impressive program. it's quite amazing how systematic the configuration can be