[RFC] Add json_encode indent parameter

Hi internals, Almost a year ago I first proposed my RFC draft to introduce a new json_encode parameter 'indent'. I have received a lot of feedback on the change, very insightful. The feedback can be boiled down to: - Accepting user input characters means you could create invalid JSON. Do we want that? Should it be complying with the spec[1]? - Preference for pure types, so int OR string, not both. So I think I made the change more complex than it should have been and considered the three options: 1) Accept indent as an int, which will result in N spaces of indent per indentation level. 2) Accept indent as a string, which will result in string N per indentation level. 3) Accept indent as an int and indent_char as string, which will result in N * indent_char per indentation level. Option 1 seems very simple and feasible while not being confusing. Option 2 seems feasible, but somewhat more complex, because user input should be validated. Option 3 seems very flexible, but in my opinion very confusing at the same time, while I'm not sure there's even a use case for this level of flexibility. I have updated the pull request[2] and RFC[3] to be based on option 1, as I think this offers clear functionality and I feel like I can't really go wrong with the indent parameter as an int. Please let me know what your thoughts are and what needs to be done to get this RFC going forward! -- Kind regards, Timon [1] https://datatracker.ietf.org/doc/html/rfc4627 [2] https://github.com/php/php-src/pull/7093 [3] https://wiki.php.net/rfc/json_encode_indentation