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by _carl_jung 2365 days ago
I'd earnestly like to hear the responses to this from the down-voters. I had the same thought and suspect there is a good reason not to use mixins.

One problem off the top of my head is run-time changing of components. An entity that inherits from multiple mixins can't inherit from new mixins (or lose existing ones) at runtime.
1 comments
skybrian 2365 days ago
Yes, ECS is usually about runtime changes in behavior. It also uses IDs rather than hard references, like in a database. Deleting an object makes references to it invalid, rather than references keeping objects alive like in a functional or object-oriented object graph.
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spankalee 2365 days ago
But the complaints about OOP in the article are all about the difficulty in modeling orthogonal traits in a single-inheritance hierarchy. That is definitely addressed with mixins.

Nothing in the "Inheritance isn't Always the Best Tool for the Job" section talks about runtime changes in behavior.

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skybrian 2365 days ago
It does touch on it towards the end:

> Most object-oriented languages are designed so that an object's underlying type will be the same for its entire lifetime. This makes things interesting when users want to scale a Circle without maintaining aspect ratio.

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