1--TEST--
2yield from on multiple trees needing merge
3--FILE--
4<?php
5
6function from($levels) {
7	foreach (range(0, 2 << $levels) as $v) {
8		yield $v;
9		if ($v == (1 << ($levels - 1)) - 2) {
10			throw new Exception();
11		}
12	}
13}
14
15function gen($gen, $level) {
16	yield from $gen;
17}
18
19$levels = 5;
20
21print "$levels levels\n\n";
22
23$all = array();
24$all[] = $gens[0][0] = from($levels);
25
26for ($level = 1; $level < $levels; $level++) {
27	for ($i = 0; $i < (1 << $level); $i++) {
28		$all[] = $gens[$level][$i] = gen($gens[$level-1][$i >> 1], $level);
29	}
30}
31
32for ($i = 0; $i < 2; $i++) {
33	try {
34		foreach ($all as $gen) {
35			var_dump($gen->current());
36			$gen->next();
37			if (!$gen->valid()) {
38				break;
39			}
40		}
41	} catch(Exception $e) {
42		print "$e\n";
43		unset($all[array_search($gen, $all)]);
44	}
45}
46?>
47--EXPECTF--
485 levels
49
50int(0)
51int(1)
52int(2)
53int(3)
54int(4)
55int(5)
56int(6)
57int(7)
58int(8)
59int(9)
60int(10)
61int(11)
62int(12)
63int(13)
64int(14)
65Exception in %s:%d
66Stack trace:
67#0 %s(%d): from(5)
68#1 %s(%d): gen(Object(Generator), 1)
69#2 %s(%d): gen(Object(Generator), 2)
70#3 [internal function]: gen(Object(Generator), 3)
71#4 %s(%d): Generator->next()
72#5 {main}
73ClosedGeneratorException: Generator yielded from aborted, no return value available in %s:%d
74Stack trace:
75#0 [internal function]: gen(Object(Generator), 1)
76#1 %s(%d): Generator->current()
77#2 {main}
78
79