JSON pretty printing indentation using tabs or double spaces

[timint]

Description

The current indentation of pretty printed JSON with json_encode() is using 4 bytes per level.
I feel we are lacking the ability to choose intendation type, i.e. for optimization.

Example:

• Tab (1 bytes)
• Two spaces (2 bytes)
• Four spaces (4 bytes)

Maybe by setting a flag to either:
JSON_PRETTY_PRINT
JSON_PRETTY_PRINT_TABS
JSON_PRETTY_PRINT_DOUBLE_SPACES

I know that we can preg_replace() it the way we want. But why waste resources if we could have it at the core.

[cmb69]

See also https://externals.io/message/114697. There was some consensus regarding a new parameter accepting int|string, but in any way, I think we should have an RFC about this.

[cmb69]

cc @bukka

[bukka]

The PR for the linked message (RFC) is here #7093 which I think is better than specifying the number in the flag. Flag could be potentially used to switch between spaces and tabs which was suggested in the thread IIRC.

[bukka]

The RFC wasn't successful possibly due to tabs so I will assign this to myself and will try to find for modified version in PHP 8.3

[timint]

@bukka Yeah I saw the voting result. Formatting is just one of many things in JSON encoding. So I think assigning two new parameters is a bit much. But I'm all ears to hear somone express the need for anything other than 2 spaces, 4 spaces or tabs.

What are your thoughts on adding two new flags instead?

Big thank you for running the whole RFC process and coding.

[KapitanOczywisty]

Seems like variant with int|string $indent got some likes, and it would be most sensible variant because of JSON.stringify similarity.

• int: 0..10 => 0 - no indent, >10 - insert 10 spaces (like JS)
• string: strlen 0..10 => 0 - no indent, >10 - use only 10 characters (like JS)
• allow producing invalid JSON
• JSON_PRETTY_PRINT is implicit when $indent>0
• JSON_PRETTY_PRINT + $indent=0 - no indentation

[maximal]

+ for having customizable indent string or at least tab possibility.

[marcing]

There is no way for json_encode to produce the same output as MySQL JSON field output:
https://bugs.mysql.com/bug.php?id=98135