Wolf, Goat, Cabbage scenario

[kostmo]

A challenge scenario that makes use of the NOT prerequisites to simplify evaluation of the win condition. These prerequisites ensure that at no point did the player ever perform some illegal action.

Demo

./scripts/play.sh --scenario data/scenarios/Challenges/wolf-goat-cabbage.yaml --autoplay

Playing

Losing

[byorgey]

I was thinking about this scenario and I like that it can tell you when it's no longer winnable (could Towers of Hanoi be redesigned to make use of that feature?). But I thought it might be nice if you get a custom losing message, e.g. "too bad! the wolf ate the sheep!". I wonder what would be needed to make that happen. Maybe each objective can have a lose_message which is shown whenever that objective is the "cause" of the failed scenario? I'm not really sure how to determine which objective is the "cause" though.

[xsebek]

@byorgey we could let a system robot show a popup notification.

It would mean two of them get shown after each other, which is not ideal.

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Since the conditions that caused the failure must have been met, how about showing “failure” reason from all of them? In this case the only one met will mention wolf and sheep. Generally we would try to produce something like parser errors - “I was expecting X or Y”.

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EDIT: Hanoi could definitely use failure condition - just check if there is more than one disc missing or they are not sorted.

I kind of like it as a test of our ability to enforce invariant though.

Still, maybe we could add a failure condition in case the player manages to fool the system robots. 😄

[kostmo]

An objective can only "fail" if it has a "prerequisites" expression that contains a negated goal reference. The BoolExpr library allows us to query for and list all of the negated references in an expression. So we could just match that list against the "completed" objectives, and display as a summary in the "Condolences" popup.