Bug #75819 [NEW]: Generators have different behavior than Iterators

From: php at fleshgrinder dot com Operating system: - PHP version: 7.2.1 Package: Class/Object related Bug Type: Bug Bug description:Generators have different behavior than Iterators Description: ------------ Generators behave differently than Iterators when calling valid on them followed by a loop. A non-rewindable iterator can be asked if it is valid by calling valid on it followed by a loop. The same is not possible with a Generator because it throws an exception stating that an already closed generator cannot be iterated. This is extremely hard to debug because the problem is not apparent at all to the reader of the code. Iterator code: https://3v4l.org/v0qAZ Generator code: https://3v4l.org/2E7EJ Also, note that HHVM/Hack behaves as expected. Test script: --------------- $it = (function () { if (false) { yield 'foo'; }})(); var_dump($it->valid()); foreach ($it as $k => $v) { var_dump($k, $v); } Expected result: ---------------- bool(false) Actual result: -------------- bool(false) Fatal error: Uncaught Exception: Cannot traverse an already closed generator in /in/2E7EJ:7 Stack trace: #0 {main} thrown in /in/2E7EJ on line 7 Process exited with code 255. -- Edit bug report at https://bugs.php.net/bug.php?id=75819&edit=1 -- Try a snapshot (PHP 5.4): https://bugs.php.net/fix.php?id=75819&r=trysnapshot54 Try a snapshot (PHP 5.5): https://bugs.php.net/fix.php?id=75819&r=trysnapshot55 Try a snapshot (trunk): https://bugs.php.net/fix.php?id=75819&r=trysnapshottrunk Fixed in SVN: https://bugs.php.net/fix.php?id=75819&r=fixed Fixed in release: https://bugs.php.net/fix.php?id=75819&r=alreadyfixed Need backtrace: https://bugs.php.net/fix.php?id=75819&r=needtrace Need Reproduce Script: https://bugs.php.net/fix.php?id=75819&r=needscript Try newer version: https://bugs.php.net/fix.php?id=75819&r=oldversion Not developer issue: https://bugs.php.net/fix.php?id=75819&r=support Expected behavior: https://bugs.php.net/fix.php?id=75819&r=notwrong Not enough info: https://bugs.php.net/fix.php?id=75819&r=notenoughinfo Submitted twice: https://bugs.php.net/fix.php?id=75819&r=submittedtwice register_globals: https://bugs.php.net/fix.php?id=75819&r=globals PHP 4 support discontinued: https://bugs.php.net/fix.php?id=75819&r=php4 Daylight Savings: https://bugs.php.net/fix.php?id=75819&r=dst IIS Stability: https://bugs.php.net/fix.php?id=75819&r=isapi Install GNU Sed: https://bugs.php.net/fix.php?id=75819&r=gnused Floating point limitations: https://bugs.php.net/fix.php?id=75819&r=float No Zend Extensions: https://bugs.php.net/fix.php?id=75819&r=nozend MySQL Configuration Error: https://bugs.php.net/fix.php?id=75819&r=mysqlcfg