Support indexing relative to 'last' position (was: Unbounded arity param)

Is it possible to use unbounded arity parameter without being the last parameters ? The following code

	@Parameters(index = "0", description = "Folder")
	private String folder;

	@Parameters(index = "1", arity = "1...*", description = "Source paths")
	private String [] sources;

	@Parameters(index = "2", description = "Destination folder path")
	private String destination;

is throwing picocli.CommandLine$MissingParameterException: Missing required parameter: <destination> when called with MyClass folder source1 source2 source3 destination

[remkop]

Thanks for raising this topic. I’ve started to think it may be worth supporting some index = last syntax in the future. That would allow something like:

@Parameters(index = “0..$-1”)
String[] sources;

@Parameters(index = “$”)
String destination;

The parsing logic for this is not straightforward though so this will be something for a future release.

[remkop]

While this is a nice idea, it turns out this is actually non-trivial to implement. I don’t see myself working on this in the near future. Closing this ticket.