Exclusive Option Groups

[ian-twilightcoder]

Flags can be mutually exclusive, but there isn't a way to do that for options. e.g. you can't have [--arch <arch> | --target <target>] Ideally these could be nested like [[--one <one> --two <two>] | [--combo <combo>]]

[rgoldberg]

Could flags, options, and arguments be allowed to be exclusive with each other by adding an exclusive: Bool = false argument to @OptionGroup()?

Current behavior is exclusive == false, which allows all of the options/flags/arguments in the group to be used in the same command line.

When exclusive == true, only one of the options/flags/arguments in the group can be used in a command line.

[rgoldberg]

Another way to implement this would be to wrap a property whose type is an enum with cases with associated values (& potentially cases without associated values, which would just be flags). I don't know if the wrapper should be @Option or something else, but, if #830 is merged, then @Option probably makes sense, with flags using a default-value option route, with their value default being nil/ignored.