rjson : a minimal json parser for rust

• Contain a single standalone lib.rs that do all the jobs.
• Impl the traits with your own structs before parse.
• A simple Impl can be, enum for Value, the same enum for Null, Vec for Array and BTreeMap for Object.
• It requires only core and alloc, nothing else, including std.
• In no_std environment, it need a global allocator to work.

Reminder

• We allow , after the last item/member of Array/Object.
• We treat unescaped line breaks as normal char, and ignore escaped line breaks.
• We do not support surrogate unicode char.
• We use f64 for all numbers, but you can use others. Remind: f64 means i52.
• We take &[char], not &[u8], and not &str.
• No stringify or encode, because they should not be a part of the traits.
• Instead of returning None, we simply ignore chars after the data.
• The position where data ends is returned through index. You can compare it with len() - 1.
• This value is also useful when Option::None returned, by indicating where the syntax error occurs.
• parse may return all possible values, not only Array and Object.