picocli

Can I have optional subcommands in picocli?

I have some existing syntax like:

mycommand --foo=x --bar=y

I want to migrate the syntax to:

mycommand A --foo=x --something=y
mycommand B --other=thing --another=thing

But I would like to continue to support the original syntax.

I don't think this is possible in picocli. Is that true? Are there any alternatives I should consider?

I have considered using an option instead of a subcommand. For example:

mycommand [--type=[OLD,A,B]]

With a default of OLD, if the type is omitted I could get the same behavior. However, now I have all of the options mixed together.

I considered using ArgGroups for this case, but do not see how they can be nested. That is, I cannot make a mutually exclusive argument group of dependent argument groups.

Solution

  • You can make the existing --foo and --bar options hidden on the top-level command. Hidden options are recognized by the parser but are not shown in the usage help message.

    Then add the subcommands with their own options.

    This provides a migration path to your new API.