Scala-cli REPL with Toolkit

[spamegg1]

Is it possible to fire up a Scala-cli REPL with the Toolkit loaded?

scala-cli repl --toolkit                                                                                          
Argument --toolkit: argument missing

To list all available options, run
  scala-cli repl --help

I'm guessing, not? Could not find anything in the documentation either.

[spamegg1]

Never mind, looks like it IS possible:

╰─ scala-cli repl --toolkit=latest                                                                                   
Downloading 3 dependencies and 2 internal dependencies
Welcome to Scala 3.3.1 (17.0.7, Java OpenJDK 64-Bit Server VM).
Type in expressions for evaluation. Or try :help.
                                                                                                                        
scala> 

It would be nice if this was documented somewhere. It's not here or here.

I will leave this here in case anyone else wonders.

[som-snytt]

I'm still not a user, only an onlooker, but it seems I have some version installed.

Pass --help to any sub-command of Scala CLI to list its options:

https://scala-cli.virtuslab.org/docs/guides/configuration#command-line

➜  scala-cli repl --help
Usage: scala-cli repl [options]
Fire-up a Scala REPL.

You are currently viewing the basic help for the repl sub-command. You can view the full help by running:
   scala-cli repl --help-full
For detailed documentation refer to our website: https://scala-cli.virtuslab.org/docs/commands/repl

Scala options:
  -P, --plugin, --compiler-plugin string*        Add compiler plugin dependencies
  -S, --scala, --scala-version version           Set the Scala version (3.2.2 by default)
  --platform scala-js|scala-native|jvm           Specify platform
  -with-compiler, --with-compiler, --with-scala-compiler  Allows to include the Scala compiler artifacts on the classpath.
  -d, --compile-out, --destination, --compile-output, --output-directory, --compilation-output /example/path  Copy compilation results to output directory using either relative or absolute path
  --toolkit, --with-toolkit version|latest       Add toolkit to classPath

[spamegg1]

They should sell "doesn't save your code anywhere" as a privacy feature that saves you embarrassment later.

😆 👍

For me (as a very casual user), searching around the docs is a cross between git and sbt UX.

Just adding a one-line scala-cli repl --toolkit=latest here would go a long way. (This is an instance of a more general "agnosticism in docs" issue that is seen everywhere in tech.) I spent near a day trying to make that (or the third option, worksheets) work.

[SethTisue]

is there a non-Scala-cli, non-script way to load the Toolkit into the REPL

The Toolkit is just an ordinary dependency. It transitively depends on the included libraries.

So in a build tool such as sbt, if add the toolkit to your libraryDependencies, then sbt console will start a REPL where the toolkit is available.

I think Mill also lets you start a Scala REPL with your code and dependencies on the classpath. Gradle and Maven, I'm not sure about.

[SethTisue]

Toolkit docs don't show how to use any one of the 6 methods mentioned

That's not entirely true, but I think it's very understandable that you didn't see it.

At the top of every "How do I....?" page in the Toolkit docs is a twistdown like this:

And if you open the twistdown, you see instructions with tabs for scala-cli, sbt, and mill:

so it's there, but if you missed it, then apparently the UX of how it's presented isn't ideal? fyi @szymon-rd @adpi2

[som-snytt]

I tried those widgets, and before I forget again, I intended to suggest that if there is a correspondence between "in-source comment" and "command line", then that could be summarized. An issue with using options is what's the semantics for foo where foo is toolkit. So the widgets don't cover when I'm just running repl from cli. I'm in late afternoon fog, so maybe I forgot what I saw earlier.

As always, worth adding, great effort on docs, I totally get FOMO. Just finding this one thing is always a hard ask.

[spamegg1]

That's fair @SethTisue I should have looked more carefully. And yes, the "Getting" tab is a bit confusing.

I still don't think I would have figured out scala-cli repl --toolkit=latest easily. I actually got it by chance after a lot of trial and error. It wasn't in Toolkit docs or Scala-cli docs, yes I should have looked more carefully into the command line options, and I couldn't think of the possibility to combine a sub-command (repl) with a command line option (--toolkit=latest) at first...

When the docs say "interactively in the Scala REPL" I used the scala command (that's what REPL means to me), and I thought Toolkit would be already loaded into the REPL.

 ➜ scala
Welcome to Scala 3.3.1 (17.0.7, Java OpenJDK 64-Bit Server VM).
Type in expressions for evaluation. Or try :help.
                                                                                                                      
scala> import os.*
-- [E006] Not Found Error: -------------------------------------------------------------------------------------------
1 |import os.*
  |       ^^
  |       Not found: os
  |
  | longer explanation available when compiling with `-explain`
1 error found

I know Scala-cli became the official runner but still, scala (the default REPL) and scala-cli are separate commands, right? Or are they aliases for each other now? Maybe there is something wrong with my setup then? I got Scala 3.3.1 from SDKMAN (in fact I was a bit involved in its release) I guess SDKMAN does not install Scala-cli along with the language?

[som-snytt]

Please reconcile with VirtusLab/scala-cli#2426 deprecate latest.

[spamegg1]

I think it's my misunderstanding that Scala-cli became the default code runner, apparently that's not going to happen until 3.4 is released. So the docs make a bit more sense now (they are future-leaning).