JSON.parse/stringify C APIs?

[martijnthe]

I think it would be nice if the jerry-core.h API would have C APIs that match JSON.parse/stringify.

Proposal API:

typedef jerry_value_t (*jerry_json_reviver_t) (jerry_value_t key, jerry_value_t value);

jerry_value_t
jerry_json_parse_utf8 (const jerry_char_t *utf8_str,
                       size_t str_sz,
                       jerry_json_reviver_t reviver);

typedef jerry_value_t (*jerry_json_replacer_t) (jerry_value_t key, jerry_value_t value);

jerry_value_t
jerry_json_stringify(jerry_value_t value,
                     jerry_json_replacer_t replacer,
                     jerry_value_t space);

Note the output of jerry_json_stringify is not a UTF-8 C string (jerry_char_t[]). Although in most cases you probably want a C string...:

1. how to allocate the buffer for the C string?
2. what's an elegant way to deal with any errors – perhaps a jerry_value_t *error_out?

Thoughts?

[martijnthe]

cc @jiangzidong

[jiangzidong]

1. how to allocate the buffer for the C string?

We can pass the allocated buf into the jerry_json_stringify, if the length is not big enough, return error.
or we pass the "malloc" function into the jerry_json_stringify, but this will make the API a little harder to use.

2. what's an elegant way to deal with any errors

Why not just return the error, like jerry_call_function did. if the ret has error flag, then it is the error.
It is the common way used in jerry-api.

[zherczeg]

1. I think the system constructs a string value, so I am not sure passing a buffer would work.
2. Yes, the returned value can have an error flag set.

[akosthekiss]

This has been implemented in #2243