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by phkahler 4287 days ago
>> I don't completely get his example

To use Minecraft as an example, a player may die from falling from too high, drowning, getting attacked by a monster. If killPlayer() is called serparately for each of those cases, he asserts that it may cause bugs due to differing context or sequencing relative to other parts of the code. If OTOH you just decrement player health in each of those places and then check for health<=0 at only one place, you eliminate that class of bugs.
2 comments
protonfish 4287 days ago
I am working on the most close-to-finished computer game I have written yet, and I have a bug caused by this exact thing! (I am learning a lot about what not to do as I go.) I plan on refactoring it to the check-once-per-loop style this weekend.
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ranran876 4287 days ago
That makes sense - though most of the time if a method call only makes sense give a particular state, it's generally set to be protected. You can still call it with the wrong state from within the same class, but I can't honestly think of a case of that happening in my work.. You generally are familiar with the workings of the class you are currently touching. If you aren't able to do that practically, then that generally means your class is simply too large.
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