As someone who uses PHP nearly every working day, this RFC is the first time I've ever seen the ${var} syntax in PHP. It only gets a very brief mention and a single use in an example snippet in the documentation[1]. I don't think I've ever seen it in production code, and would have flagged it as a typo if I found it during code review.
Removing {$var}, on the other hand, would have broken practically every string interpolation I've ever written, and probably about 50% of all uses of string interpolation in the ecosystem.
The ${var} syntax has always been my preferred approach. In all the editors I’ve used it syntax highlights as if you had typed “.$var.”, rather than just displaying $var in bold and same colour as the string literal. Plus it allows for more flexible use of arrays or objects
Sad to see the way PHP is killing backwards compatibility. There has always been a way to bodge it with previous BC breaks like removal of mysql and mcrypt, but this isn’t fixable without code changes. I don’t even see any advantage, seems like change for the sake of change
Removing {$var}, on the other hand, would have broken practically every string interpolation I've ever written, and probably about 50% of all uses of string interpolation in the ecosystem.
[1]: https://www.php.net/manual/en/language.types.string.php#lang...