Yield from

[thekid]

This pull request implements yield from as described in this PHP 7.0 RFC in both PHP and XP and makes it work in PHP >= 5.5

var values() {
  yield 1;
  yield 2;
}

var including() {
  yield 0;
  yield from self::values();
  yield 3;
}

// 0, 1, 2, 3

• Yielding from a generator
• Yielding from an iterator
• Yielding from an array

[thekid]

Fails on HHVM: https://travis-ci.org/xp-lang/compiler/jobs/81253540:

HHVM

$recv= (yield $next);  // Fatal error: syntax error, unexpected T_YIELD
$recv= yield $next;    // Still doesn't work but at least parses!

PHP

$recv= (yield $next);  // Works as expectred
$recv= yield $next;    // Parse error (syntax error, unexpected '$next' (T_VARIABLE))

_Argl 😱_ - see also facebook/hhvm#1627

[thekid]

Choosing emitter based on PHP runtime version has also been applied to master branch.