Clojurians Log v2

If I would do one more talk this year about bb, would you like me to go into: 1) babashka / sci internals 2) dedicated talk on babashka pods 3) other (respond in thread) Vote here: https://twitter.com/borkdude/status/1317072035542171650

I notice that *file* isn't bound when I am using the nrepl server (which makes sense). Is the best way to work around this to just manually bind it during my repl sessions?

I would recommend something like this, where most of the code that deals with the filename takes it as an argument:

(defn process
 [filename]
 (println filename))

(when *file*
  (process *file*))

I've made a couple of updates to babashka process: https://github.com/babashka/process. Breaking changes: - use slurp to realize output into strings, :out and :err are always streams - :exit is always a delay, forcing the delay will wait for the process to end - :throw is removed, use (wait (process ...) {:throw true}) to explicitly throw

@mitchell_clojure Are you running into an unexpected error because of this?

Thanks, @nate, I think that is the way I am going (or setting a default value for *file* if not bound). @borkdude no breaking errors because of this, just trying to make my REPL flow ergonomic. I noticed that evaluating the buffer from cider did not produce the same result as running the script. It was simple to track down the cause and work around. I am not sure if the bb nrepl server can see which files forms come from, but that is the only place where I think this could be fixed

it is small potatoes regardless and maybe not worth rebinding the var root every time the nrepl server gets a message

@mitchell_clojure Can you give an example of how to reproduce this difference? I do have emacs + CIDER

I see, can reproduce it

will fix

ah cool, was just about to send the repro

thank you!!

Fix pushed to master https://github.com/babashka/babashka.nrepl/issues/31

I think I solved most of the problems I had doubts about in this lib. Might be ready for inclusion in bb. One issue I could not solve: https://github.com/babashka/process#piping-infinite-input It seems that io/copy of an infinite input stream never flushes to the output stream or something?

One thing of doubt: should (wait (process ...)) throw by default when the exit code is non-zero? Now it only does so when (wait (process ....) {:throw true})

I think it might make sense to throw by default...

(-> (process ["ls" "foo"]) (wait) (process ["cat"]))

I think throw by default makes sense

can you do a {:throw false} if you don't want it to throw?

The above can now also be written as:

(-> @(process ["ls" "foo"]) @(process ["cat"]))

hm, a couple of thoughts to consider: 1. default in bash is not to throw an exception (as in it doesn't exit the script) 2. defaults in bash might not be a sensible thing to follow

thanks :)

does clojure.java.shell throw if the command errors?

I can't remember

no, it doesn't. which is something I probably always wrap myself, or not, if I'm too lazy

I'm trying to completely mimic clojure.java.shell either though. if you want to use that, use that

From the docs: The function wait takes a process, waits for it to finish and returns it. When the exit code is non-zero, it will throw, which can be turned off with `{:throw false}`.

clojure
user=> (-> (process ["ls" "foo"]) wait :exit deref)
Execution error (ExceptionInfo) at babashka.process/wait (process.clj:74).
ls: foo: No such file or directory

clojure
user=> (-> (process ["ls" "foo"]) (wait {:throw false}) :exit deref)
1

clojure
user=> @(process ["ls" "foo"])
Execution error (ExceptionInfo) at babashka.process/wait (process.clj:74).
ls: foo: No such file or directory

Looks very good

I found the issue with piping infinite streams. If I put a flush in io/do-copy for stream -> stream:

(defn copy [in out opts]
  (let [buffer (make-array Byte/TYPE (buffer-size opts))]
    (loop []
      (prn :copy)
      (let [size (.read in buffer)]
        (when (pos? size)
          (.write out buffer 0 size)
          (.flush out)
          (recur))))))

Pod for SQL Server support: https://github.com/xledger/pod_sql_server

Amazing, thanks!

Any reason why not to use keywords as keys instead of strings btw?

Oh no, I guess it probably works either way, let me verify and update the readme

Just built the project on macOS as well: ` $ dotnet build Microsoft (R) Build Engine version 16.7.0+7fb82e5b2 for .NET Copyright (C) Microsoft Corporation. All rights reserved. Determining projects to restore... Restored /private/tmp/pod_sql_server/pod_sql_server.csproj (in 3.27 sec). pod_sql_server -> /private/tmp/pod_sql_server/bin/Debug/netcoreapp3.1/pod.xledger.sql_server.dll Build succeeded. 0 Warning(s) 0 Error(s) Time Elapsed 00:00:05.23

This works:

(require '[babashka.pods :as pods])

(pods/load-pod ["dotnet" "bin/Debug/netcoreapp3.1/pod.xledger.sql_server.dll"])

(require '[pod.xledger.sql-server :as sql])

But I don't have a sql server db. So I just tried the first example to see if it would produce an error, but it seems to hang

Ah interesting. Do you think that form is better? I was going to try and eventually merge it all to one .exe (it isn't yet), because I think they plan to release stuff that lets you bake in the dotnet dependency, so even people without it can run the code

Oh strange, I'll try to fix to repro + fix that

which form?

dotnet my.dll

no, on macOS it just baked a .dll, I can't run .exe here

ohh gotcha

I wonder if the IntegratedAuthentication would work on Mac, I'd guess not because I think it relies only on active directory

not sure. but anyway, I put some logging in the catch of the try/catch of HandleVar_Execute_Internal and it doesn't seem to reach there, it's waiting for something

Not sure if that's the same for you since I'm on macOS, which is a but unusual for this pod maybe

Strange, I get the exception. Does it help if you add await _writer.FlushAsync(); at the end of SendException?

} catch (Exception ex) {
                Console.Error.WriteLine("in try");
            
                await SendException(id, ex.Message);
            }

ah

but it does print earlier logs

oh. I wonder if it is a different and bizzarely high connection timeout

could be, I can let it sit there for a few minutes

Ah, after a while it seems to get stuck in a loop

Oh, for what code?

async Task SendException(string id, string exMessage, object exData = null) {
            Console.Error.WriteLine("dude");
        

Hm I guess it must be that outer exception handler catching a new exception when sending the exception message

ah if I remove that line, then I get this:

7: (sql/execute! {:connection-string "Data Source=my.db.host;Application Name=my.script;Initial Catalog=my_db_name;Integrated Security=True"
   ^--- A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: TCP Provider, error: 35 - An internal exception was caught)
8:                :command-text "select top 1 * from sys.objects"
9:                :multi-rs true  ;; Return multiple result sets, or just the first?
10:                })

but I do need to kill dotnet since it seems to stay running

Ok yea that is what I get too

and activates my CPU :)

strange, is that related to the pod load/unload thing?

This is what you removed, right? https://github.com/xledger/pod_sql_server/blob/master/PodHandler.cs#L37-L39

no, I only removed my own Console.Error.WriteLine("dude");

yeah, could be related to the unload error

let me me try with a fresh bb

ok

yep, that's probably it :)

sorry for the hassle

np, thanks for testing it

I wonder if it would work with a real SQL Server DB... is there like a free Azure thing I could connect to? I'd be really cool to have non-Windows users use this too

There might be a trial or something, and that would probably work with this

Otherwise it looks like you can install SQL Server on mac if you have docker: https://database.guide/how-to-install-sql-server-on-a-mac/

hmm yeah, docker!

going to test this tomorrow, thanks man