Scanf string using scanset (character class)

[Harvie]

Hello,
i've found that unlike original scanf(), the json_scanf() does not support "scanset" feature. Eg.:

json_scanf(in, sizeof(in), "{ str:%30[0-9a-zA-Z ] }", out);

should scan string of up to 30 characers from set [0-9a-zA-Z ] = both cases of alphanumeric characters and space. But it does not work in frozen.

Have you considered implementing this useful feature of scanf() to json_scanf()?

Also it would be nice to have some way to get pointer and length of escaped JSON string. sometimes there's no need to unescape so i would love to have way to parse string without using dynamic memory allocation, so it's faster and i don't have to free() anything...

Something like this would be great:

json_scanf(in, sizeof(in), "{ str:%.*s }", out.len, out.ptr);

i've used %.*s because that's how printf() handles situation where you want to pass string length along with pointer... But maybe %S would be nice option as well. in such case json_scanf() should return whole length of string minus the quotes (but still json escaped).