On Thu, Apr 08, 2021 at 11:33:13AM -0700, Junio C Hamano wrote:
> > +/**
> > + * Same as `git_parse_maybe_bool`, except that "auto" is recognized and
> > + * will return "2".
> > + */
> > +int git_parse_maybe_tristate(const char *);
>
> A false being 0 and a true being 1 is understandable for readers
> without symbolic constant, but "2" deserves to have a symbolic
> constant, doesn't it?
I had the same thought.
This "tristate" really has four outcomes: true, false, auto, or error.
Since the caller has to then check for error or for "auto" themselves,
it feels like it is not actually making their lives any easier. I.e.,
without it:
if (value && !strcmp(value, "auto"))
do_auto();
else {
int b = git_parse_maybe_bool(value);
if (b < 0)
do_error();
else if (b)
do_true();
else
do_false();
}
but with it:
b = git_parse_maybe_tristate(value);
if (b < 0)
do_error();
else if (b == 2)
do_auto();
else if (b)
do_true();
else
do_false();
which is the same thing, swapping string comparison for a numeric one.
And a caller of git-config has the same thing: it still has to check for
"auto" in the output it gets (which it could just do via bool-or-str).
It seems like it would be more convenient if you could pass it a bool
value to turn the "auto" into. E.g., if you could do:
b = git_parse_maybe_tristate(value, 1); /* default to "1" */
if (b < 0)
do_error();
if (b)
do_true(); /* true, or maybe "auto" */
else
do_false();
I dunno. That would probably be hard to represent via "git config
--type". And some callers probably do care about "auto" versus "true".
It also feels funny calling this "tristate". Aren't there other
tristates we could have besides "auto"? The command-line option is
bool-or-auto, which is descriptive. Should this use a similar name?
-Peff
