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YAKINDU Statechart Tools (http://www.statecharts.org)
Eclipse Public License 1.0
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Missing documentation of behavior of events in guards #3211

Closed z3rone closed 3 years ago

z3rone commented 3 years ago

In version 3.5.9 it is possible to write events in transition guards. Doing so results in the transition being activated if the source state is entered because of that event being raised. This behavior seems not to be documented in the language reference.

Further more the behavior conflicts with the UML behavioral state machine definition. As states are stable vertices, the transitioning process should stop in a (simple) state. Further transitioning would require a new event being dispatched. However, the previous event would be consumed at this point, so the guarded transition should not become enabled.

Example of the behavior: image

When event a is fired (a single time) the transitioning continues up to state C.

tkutz commented 3 years ago

This is indeed incorrect. When event a is only fired one single time, state B should be activated.

This is already fixed in the latest version. You might want to update.

Note, that we have released a new version 4 of Statechart Tools. But you cannot update directly from 3.x. to 4.x, you need to download version 4. However, your 3.x models should also work with version 4 (check our migration guide for more details).

Regarding the documentation you are right, it is missing there.

tkutz commented 3 years ago

I created an issue for the documentation part in our internal tracker.

I will close this one here, as the actual behavior is already fixed.