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Date: Tue, 11 Jul 2017 20:41:17 +0200
To: PHP internals <internals@lists.php.net>
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Subject: String interpolation shortcomings
From: ilija.tovilo@me.com

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Hi everyone

String interpolations are a great feature. They make your code more reada=
ble and can reduce the number of allocations PHP has to make.

Unfortunately, PHP is very restrictive in what kind of expressions string=
 interpolation accepts. The only time you can actually use it is if your =
expression starts with the =60=24=60 symbol. You cannot use it for:

- =46unction calls
- Infix expressions
- Constants or class constants
- Instantiations
- Expressions in parentheses

Or anything else that doesn=E2=80=99t begin with the =60=24=60 symbol.

Even more unfortunate is that =60=24=7Bfoo()=7D=60 is equivalent to =60=7B=
=24foo()=7D=60 which means we cannot simply extend the current syntax to =
support all expressions. Of course, we could deprecate the =60=24=7Bfoo()=
=7D=60 syntax and reintroduce it with a different semantic meaning after =
some time but this is far from satisfying.

There is also the possibility of introducing new syntax for string interp=
olation and deprecating the old one after a transition period (e.g. =60=E2=
=80=9DHello =5C(world())=E2=80=9D).

Does anyone think this is worth fixing=3F



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