Negating options

[Denys Duchier]

John A Meinel <john at arbash-meinel.com> writes:

> This requires that global options occur before the command. People
> didn't like this. --quiet, --no-plugins should all be 'global' commands,

No, it doesn't.  --no-plugins is a bit special, so yes that one needs to occur
early.  But a --quiet global option does not have to occur before the command:
that is why my description suggested to _extend_ the parser with the command
specific options.  In this manner, nested subcommands always permit options of
super commands to be interspersed with their own.  I am not speaking
theoretically: I have actually tested this type of layered processing.

> So is there another way to have optparse handle this? Does it have
> "don't complain about unknown args" so that we can run one pass with the
> global option parser, and then run a second pass with the command
> specific one?

It is not possible to safely proceed in this fashion because during a 1st pass
you might not be aware of argument-taking options for the 2nd pass.  If
--no-plugins were actually supposed to be the argument value for a subcommand
option: extracting it on the 1st pass whould completely mess things up.

That's why I suggested the allow_interspersed_args=False based method of
iterative processing: only parse up to the first non recognized argument: if
that one is a subcommand, then extend the parser with options for that
subcommand and process the rest of the leftover.  repeat until done.

Cheers,

--Denys