getopt upgrade

[Robert BuRnEr Schadek]

please make this happen.

maybe a user defined help printing function would be useful. I could
image that printing the help information is something somebody would
like to modify.

On 01/03/2014 06:16 PM, Andrej Mitrovic wrote:
> On 9/3/13, Jacob Carlborg <doob at me.com> wrote:
>> Could we get some form of API to set a header and footer that is printed
>> with the help text. Possible idea:
>>
>> bool help;
>>
>> getopt(args, "h|help", &help, @doc("Show this message and exit.");
>> getopt.header = "Usage foo [options]\nVersion 0.0.1\n\n";
>> getopt.footer = "\n\nUse the 'h' flag for help.";
> I have a simpler idea, and I'm already working on the following features:
>
> // no help string:
> getopt(args, "foo", &foo);
>
> $ app --help
>
> I think it would be nice if getopt simply listed all the options here,
> even if there are no help strings attached and no --help options
> explicitly defined.
>
> // help string is in-between the name and the address,
> // which is an easy disambiguation for getopt:
> getopt(args, "foo", "describe foo option", &foo);
>
> $ app --help
>
> This would print out all the options and their individual help strings
> (when present).
>
> // header and footer is described after an explicit "help" option:
> getopt(args, "foo", "describe foo option", &foo,
>                   "help", "this is the header for --help", "this is
> the footer for --help");
>
> $ app --help
>
> This would print out the header, followed by all the options and their
> individual help strings, followed by the footer.
>
> Additionally, I was thinking that getopt could be smart enough that if you run:
>
> $ app --help=foo
>
> It would only display the help string for the foo option (if present).
>
> Another addition: when parsing the runtime argument for some option fails:
>
> bool threads;
> getopt(args, "threads", "use multithreading", &threads);
>
> $ app --threads=1
>
> Currently this prints:
>
> -----
> std.conv.ConvException at std\conv.d(2794): Can't parse string: bool
> should be case-insensitive 'true' or 'false'
> -----
>
> But if a help string is present we could append the help string to the
> exception message:
>
> -----
> std.conv.ConvException at std\conv.d(2794): Can't parse string: bool
> should be case-insensitive 'true' or 'false'
>
> Help string for option 'threads': use multithreading
> -----
>
> The one special case is when the user actually wants --help to store
> to a variable, e.g.:
>
> getopt(args, "foo", &foo, "help", &help);
>
> In that case getopt would simply parse --help as a regular option,
> rather than attempt to print out the help screen. This avoids any
> existing code from breaking.
>
> Thoughts? Andrei?