General purpose library for name/value pairs.

[Pawel Jakub Dawidek]

On Fri, Jul 26, 2013 at 12:26:15AM -0700, Jordan Hubbard wrote:
> 
> On Jul 25, 2013, at 1:28 PM, Pawel Jakub Dawidek <pjd at freebsd.org> wrote:
> 
> > Returning to this thread after a short break. I removed all
> > {,u}int{8,16.32.64} types and implemented only 'number' type which is
> > uint64_t. Looks much nicer now.
> 
> Indeed!
> 
> > Not sure if you looked at the API, but with nvlist you can lookup
> > element by name:
> > 
> > 	const char *nvlist_get_string(const nvlist_t *nvl, const char *name);
> 
> Sorry, I must have misunderstood that function since I thought it would just get you a named string - you can also do something like this?
> 
> 	{ { "name", "Pawel Jakub Dawidek" }, { "age", 37 }, { "favorite-float-num", 1.E027 }, { "likes", { "cats", "ZFS", "fashion models" } }, { "company", "wheel systems" } }
> 
> And then look up "name" and get a string, "age" and get a number, "favorite-float-num" for a float, "likes" for an array of strings, etc?

Exactly. The code would look like this:

	static const char * const *likes = {
		"cats",
		"ZFS",
		"fashion models"
	};
	nvlist_t *nvl;

	nvl = nvlist_create(0);
	nvlist_add_string(nvl, "name", "Pawel Jakub Dawidek");
	nvlist_add_number(nvl, "age", 37);	/* XXX: Not my age, yet:) */
	/* No floats. */
	nvlist_add_array_string(nvl, "likes", likes, 3);
	nvlist_add_string(nvl, "company", "Wheel Systems");
	if (nvlist_error(nvl) != 0)
		errx(1, "Unable to create nvlist.");

Then:

	printf("Name: %s\nAge: %d\nCompany %s\n",
	    nvlist_get_string(nvl, "name"),
	    (int)nvlist_get_number(nvl, "age"),
	    nvlist_get_string(nvl, "company"));

-- 
Pawel Jakub Dawidek                       http://www.wheelsystems.com
FreeBSD committer                         http://www.FreeBSD.org
Am I Evil? Yes, I Am!                     http://mobter.com
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