On unpack, one may want to mix `JSON_STRICT` and optional keys by using
a format like `{s:i,s?o!}`. Unfortunately, this fails the stric test
with `-1 object item(s) left unpacked` error when the second key is not
specified.
To fix that, we iter on each key and we check if we have successfully
unpacked them. This is less efficient than the previous method but it
brings correctness.
The decimal point '.' is changed to locale's decimal point
before/after JSON conversion to make C standard library's
locale-specific string conversion functions work correctly.
All the tests now call setlocale(LC_ALL, "") on startup to use the
locale set in the environment.
Fixes GH-32.
The keys which are stored temporarily to a hashtable to make sure that
all object keys are unpacked, were hashed with the object key hashing
function. It is meant to compute hashes for object_key_t values, and
it works incorrectly for plain strings.
Fixed by introducing suitable functions for hashing and comparing
strings for string-keyed hashtables.
Expand the pack/unpack API: json_(un)pack is the simple version with
no error output, json_(un)pack_ex has error output and flags,
json_v(un)pack_ex is a va_list version of json_(un)pack_ex.
Implement unpacking flags:
- JSON_UNPACK_ONLY turns off extra validation, i.e. array and object
unpacking doesn't check that all items are unpacked. This is really
just convenience for not adding '*' after each object and array.
- JSON_VALIDATE_ONLY turns off unpacking, i.e. no varargs are expected
and nothing is unpacked.
Note that we pass va_list pointers around instead of just va_lists, which
would seem more intuitive. This is necessary since the behaviour of va_lists
passed as function parameters is finicky. Quoth stdarg(3):
If ap is passed to a function that uses va_arg(ap,type) then the value
of ap is undefined after the return of that function.
The pointer-passing strategy is used by Python's Py_BuildValue() for the same
purpose.
