Add _NEWHANDLER option for ON ERROR GOTO... #531
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- added keyword and adapted compile tests
RhoSigma-QB64
added
bug
flukiluke
approved these changes
Aug 23, 2024
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This adds the _NEWHANDLER keyword to make a clear difference between existing legacy code and new QB64-PE specific code. It was required as the simple addition of a history chain to the legacy ON ERROR GOTO syntax introduced a potential memory leak to existing legacy code.
Now with _NEWHANDLER the possibility for this memory leak still exists and special care should be taken when using it, but at least existing code will not break anymore.
Legacy Syntax:
ON ERROR GOTO {label|0}Extended QB64-PE Syntax:
ON ERROR GOTO [_LASTHANDLER|_NEWHANDLER label]where the use of _NEWHANDLER will save the current handler to the history chain before actually setting the new handler, and _LASTHANDLER is used to restore back to the most recently saved handler.
The use of the legacy
ON ERROR GOTO 0will also reset/clear all saved history entries.