Added alias jython-cli-next

[wfouche]

@jeff5 , @Stewori - I've made a small change to the jbang-catalog.json configuration file to allow multiple versions of Jython to be used.

$ jbang run jython-cli@jython -V
2.7.4

$ jbang run jython-cli-next@jython -V
2.7.5b1

JBang is being extended to allow the version string to be specified as part of the alias on the command-line:

• jbang run jython-cli:2.7.5b1@jython -V

but this functionality is not yet available.

Defining a unique alias (jython-cli-next) to launch the 2.7.5b1 version is the best we can do at the moment.

[jeff5]

This seems like a good idea (until the newer feature). I'll pull the PR branch and try it.

[jeff5]

LGTM. Any objections to merging? (Probably rebase merge as only one commit.)

[wfouche]

Please merge. :-)

[jeff5]

Testing a minute or two after the merge produces somewhat inconsistent results. It's not our fault I think, so I just exhibit it as a curiousity.

PS vsj> jbang jython-cli-next@jython -V
[jbang] [ERROR] No alias found with name 'jython-cli-next'
[jbang] Run with --verbose or -x for more details. The --verbose or -x must be placed before the jbang command. I.e. jbang --verbose run [...]
PS vsj> jbang jython-cli@jython -V
Jython 2.7.4
PS vsj> jbang jython-cli-next@jython -V
Jython 2.7.4

Yes, really. And it did it a second time.

PS vsj> jbang jython-cli-next@jython -V
Jython 2.7.4
PS vsj> jbang run --fresh jython-cli-next@jython -V
[jbang] Resolving dependencies...
[jbang]    org.tomlj:tomlj:1.1.1
[jbang] Dependencies resolved
[jbang] Building jar for JythonCli.java...
Jython 2.7.5b1
PS vsj> jbang jython-cli-next@jython -V
Jython 2.7.5b1

[wfouche]

JBang caches the jbang-catalog.json file + other files, and periodically invalidates cache entries to force fresh copies of files to be fetched. It looks like improvements can be made in this area of JBang.