support generating classpaths embedded on command line

[maxandersen]

I find that sometimes cli's out there need a classpath and it can be quite tedious to type out.

I wonder if like done in #1043 where %{url} fetches content and make it available as a file we could support %{deps://DEPS syntax} to generate classpath.

i.e.

jbang sqlline@maxandersen -cp %{deps:org.hsqldb:hsqldb:RELEASE,..} other args

[maxandersen]

@quintesse tell me if i'm crazy or we should just do this :)

[quintesse]

It doesn't seem totally crazy, no.
But do we have a clear use-case where this enables something we can't do in another way?

Because I don't think you're interested in passing in the classpath as an argument to a script, right? (Which is what %{url} was meant for)

Edit: wait, I now re-read your example and see that you do actually suggest that. Ok, then yes, it seems like a perfect example of something like that.

Not sure if I'd go with the deps: though. I mean, if we're able to detect the difference in JBang between running something as a URL or a Maven dependency, we should be able to do the same for %{ ... } , right?

Something like %{ url | deps } or simply %{ url | dep } (singular dep), because you can always just put several %{ ... } on a line.

[maxandersen]

My usecase is https://github.com/jupyter-java/jbang-catalog/blob/main/installkernel.java where some of kernels especially the kotlin one expects a seperate classpath list as argument.

Similar to the sql drive tooling above.

Reason for deps: prefix is that we allow https urls to GitHub repo as deps too which would need treating differently i think?

[quintesse]

Reason for deps: prefix is that we allow https urls to GitHub repo as deps too which would need treating differently i think?

You're probably right. I don't think it would be impossible to come up with a scheme where we wouldn't have to use the prefix, but it might mean that we'd have to choose one interpretation over another.

Still, I like the simplicity of %{org.hsqldb:hsqldb:RELEASE}. Perhaps we can make the prefix(es) optional where they work to force one interpretation over another when the contents is ambiguous? Eg: %{org.hsqldb:hsqldb:RELEASE} would be ok, because it's obviously not an URL. The same with %{http://www.google.com}. But the issue would be %{https://github.com/jbangdev/jbang}.

In that case we can add the option to add a prefix: url or dep. I think it's good to have both for consistency.

And then we can use:

%{url:https://github.com/jbangdev/jbang}

and

%{dep:https://github.com/jbangdev/jbang}

(Btw, using "dep" here for the examples, but we can do "deps" too of course.)