[Libguestfs] [PATCH v2 2/3] mllib: Use L"..." and S '...' for long and short options.

[Richard W.M. Jones]

On Mon, Jul 18, 2016 at 03:21:31PM +0200, Pino Toscano wrote:
> On Monday, 18 July 2016 11:46:46 CEST Richard W.M. Jones wrote:
> > ---
> 
> Note that this changes the way -foo options are handled: this basically
> makes them as --foo, but still working as -foo because getopt_long_only
> is used.  IMHO either add a new M".." ([M]edium or [T]runcated or
> [D]ash or ...), or turn S to get a string instead.

Do you mean only for the 'virt-v2v --help' output?  I don't think
there is any other place in the code where the M option would be
handled differently from the L option.

> > -  let validate_key key =
> > -    if String.length key == 0 || key == "-" || key == "--"
> > -       || key.[0] != '-' then
> > -      invalid_arg (sprintf "invalid option key: '%s'" key)
> > +  let validate_key = function
> > +    | L"" -> invalid_arg "Getopt spec: invalid empty long option"
> > +    | L"help" -> invalid_arg "Getopt spec: should not have L\"help\""
> 
> Theoretically both Arg and the current Getopt allow applications to
> provide an own handler for --help, instead of the built-in one.

Sure, but I don't think that's a good idea :-)

> > +    | L s when String.contains s '_' ->
> > +       invalid_arg (sprintf "Getopt spec: L%S should not contain '_'"
> > +                            s)
> 
> Why this limitation?

I guess we don't need this limitation.  It's there to catch accidental
underscores.  If we actually have to use underscore parameters then we
can remove this later.

> IMHO it'd be better to sort the specs at this point, like done before;
> otherwise, --help (and potentially any non-hidden built-in option added
> here) will be shown only at the end of the other specs.

At the beginning of the list, and it was deliberate.  However it's
just a matter of preference, and the options could be sorted later.

Rich.

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