Add pointer to boolean .present field to opt desc, which (if non-NULL)
will be set to TRUE if the argument in question is present on the
command line. Unchanged otherwise.
Several changes at once, just to not have to change the same lines
several times over:
- Use designated initializers to initialize opt desc arrays.
- Only initialize the needed fields.
- Remove arg_id (short options) as unused.
- Replace opt_type and output_var with several type safe output
variables, where the output variable being non-NULL determines the
type. Introduce checks to ensure only one is set. The downside is
some waste of const space per argument; this could be saved by
retaining opt_type and using a union, but that's still pretty
verbose.
- Fix some variables due to the type safety. Mostly a good thing, but
leads to some enums being changed to ints. This is pedantically
correct, but somewhat annoying. We could also cast, but that defeats
the purpose a bit.
- Terminate the opt desc arrays using {}.
The output variable type safety and the ability to add new fields for
just some output types or arguments are the big wins. For example, if
we wanted to add a variable to set when the argument is present, we
could do so for just the arguments that need it.
Beauty is in the eye of the beholder, but I think this looks nice when
defining the arguments, and reduces some of the verbosity we have
there.
NOTMUCH_OPT_INHERIT expects a notmuch_opt_desc_t * pointer in
output_var.
The "Unrecognized option" message was moved out of parse_option() to
not be emitted twice or when parsing a non-inherited option.
Previously, the cli parser was a little erratic in what errors it
reported and would fail silently in many cases (for example, when no
argument was passed to an integer option). This was particularly
annoying as the user could not (easily) tell whether the command
failed or just there were no search results.
This patch tries to make the handling consistent and return a helpful
error message in all cases.
This changes the parsing for "keyword" options so that if the option
is specified with no argument the argument is parsed as if it were
passed an empty string. This make it easier to add options to existing
boolean arguments (the existing --option can default to TRUE).
As we noticed when Jani kindly converted things to getopt_long, much
of the work in argument parsing in notmuch is due to the the key-value
style arguments like --format=(raw|json|text).
The framework here provides positional arguments, simple switches,
and --key=value style arguments that can take a value being an integer,
a string, or one of a set of keywords.
