Assist in creating subcommand groups that add parameters and/or behavior

[Yann Kaiser]

Usefulness and API to be determined.

Clize currently supports sharing behavior and parameters through decorators. They offer flexibility in that they can be used arbitrarily, at the cost of limiting usage of those parameters to only after all arguments that designate subcommands. example:

$ prog command --quiet    # ok because command is decorated with @with_output_control
$ prog --quiet command    # not ok because only command's decorators know of --quiet

This feature request proposes a more elaborate API be devised for creating groups of commands, one that allows for behavior and parameters to be processed at the group level.

[Yann Kaiser]

In other argument parsers:

• argparse's subparsers
• click's groups