Refactor function scopes: Capturing and returning

[thekid]

Idea

• fn captures variables from the surrounding scope, see https://wiki.php.net/rfc/scope-functions
• function does not
• => ... is short for { return ... }

What this applies to

Methods:

class T {
  public function name() => $this->name; // 🆕

  // Equivalent of
  // public function name() { return $this->name; }
}

Capturing closures:

fn($a, $b) => $a + $b;

// Equivalent of
// fn($a, $b) { return $a + $b; } // 🆕

Closures:

function($a, $b) => $a + $b; // 🆕

// Equivalent of
// function($a, $b) { return $a + $b; }

Functions:

function add($a, $b) => $a + $b; // 🆕

// Equivalent of
// function add($a, $b) { return $a + $b; }

[thekid]

With this the library is backwards-compatible for all instances using foreach / emitAll() on functions', closures' and methods' body member.

[thekid]

This can be removed in the next major release

[thekid]

Released in https://github.com/xp-framework/ast/releases/tag/v12.2.0