This essay says that inheritance is harmful and if possible you should “ban inheritance completely”. You see these arguments a lot, as well as things like “prefer composition to inheritance”. A lot of these arguments argue that in practice inheritance has problems. But they don’t preclude inheritance working in another context, maybe with a better language syntax. And it doesn’t explain why inheritance became so popular in the first place. I want to explore what’s fundamentally challenging about inheritance and why we all use it anyway.
Mathematically, the union of disjoint sets is often called the sum. This is a natural name because when you look at the number of elements (or in general, any measure), it will be the actual numeric sum.
Why the emphasis on “disjoint”? Aren’t integers a subset of floats? Would that mean then that
int | float
is incorrect?Anti Commercial-AI license
In most programming languages, integers are not considered a subset of floats, so when you have the type
Int | Float
, you can distinguish3
from3.0
.