Unescape constant strings

[rvanvelzen]

Fix #142

[JanTvrdik]

I would expect double quoted string to support the same escaping sequences as PHP. See https://github.com/nikic/PHP-Parser/blob/master/lib/PhpParser/Node/Scalar/String_.php#L71-L130

[rvanvelzen]

I initially was going to do so, but didn't for parity with Psalm. I'd be more than happy to mirror PHP's functionality though, if @ondrejmirtes also agrees :)

[ondrejmirtes]

Yes, parity with PHP would be great, we're in a very edge case territory anyway. And inform the Psalm maintainers afterwards 😊 BTW is this a BC break? Do we need a feature flag for the new behaviour?

[rvanvelzen]

I've basically copied most of the implementation from PHP-Parser, but that probably needs to be mentioned somewhere. Any suggestions?

[ondrejmirtes]

A github.com permalink in a code comment would be fine I think.

[ondrejmirtes]

This is gonna need some modification and a bleedingEdge toggle in phpstan-src too, right?

[rvanvelzen]

It should only require a feature toggle :)

[ondrejmirtes]

What about the bool $trimStrings = false? parameter? Shouldn't we eventually get rid of it? In PHPStan it's probably called with false...

[rvanvelzen]

What about the bool $trimStrings = false? parameter? Shouldn't we eventually get rid of it? In PHPStan it's probably called with false...

I would definitely like to get rid of it, especially because it is used with both true/false internally. @method parameter default values are parsed without unescaping, which eventually leads to unescaped values in PHPStan as well. Those never really propagate anywhere though…

There isn't a pure BC-friendly approach to removing it I'm afraid, but I really don't think it should be used at all so maybe it's not that bad?

[ondrejmirtes]

Thank you!