feat: Additional Arguments

[TheAngryByrd]

Description

Hi there! I work on a tool dotnet-mono that allows mono programs to be run under the dotnet cli tooling and I'm trying to be as compatible with dotnet-run's options as possible. I'm trying to imitate their use of -- <additional arguments>.

$ dotnet run --help
Usage: dotnet run [options] [[--] <additional arguments>...]]

...

Additional Arguments::
  Arguments passed to the application that is being run.

How would I go about that in Argu? Is there a way to specify this or a way to override the usage as to show this option and I can parse it out myself? Thanks!

Related issue: https://github.com/TheAngryByrd/dotnet-mono/issues/33

[rmunn]

BTW, in Unix convention, a double-dash (--) argument means "stop parsing arguments now, and pass everything after the -- literally to the program". So for example, if you want to grep for the string -v in file.txt, you would use grep -- -v file.txt. Without the -- parameter, the -v would mean "invert match". See https://unix.stackexchange.com/questions/11376/what-does-double-dash-mean-also-known-as-bare-double-dash for more details.

Since this is a standard Unix convention, it would be a good idea for Argu to allow treating a user-defined string (defaulting to -- but changeable) as a "stop parsing arguments at this point" marker.