> To me the pragmatic essence of OOP is that it groups the data and the code which works on that data. If there's a pure C library which has a function to create some sort of 'context' and then has functions which take a context pointer as argument, then this is object-oriented to me. Most other features, like classes, inheritance, runtime polymorphism is just sugar-topping; useful in some cases, but not the essence.
You nailed it.It's just more elegant to group things as a class than having fopen,fread,fclose where you pass a resource as a first argument. Polymorphism then is the consequence of that design since you could have the same interface for a file,a socket,an archive or whatever. When in use,you can ignore the nature of the resource and just remember it can be opened,read or closed,which allows to write abstract logic on top of it.
I see no reason pure modularization wouldn't achieve the same thing. In fact, that's what I took OOP to mean for a long time. But it doesn't need to be bound to the data, or mutable as in not functional. If member functions return objects and data, they can be used in a functional approach and to construct polymorphism or inheritance through currying.
Are the OOP language features the essence of OOP? 'Everything is an object'? Multiple inheritance?
if an object can be reduced to a symbol like a void-pointer to data or a function that returns data and this object can be related to others on a graph, then that's still general enough.
Imperative Programms as well as Object models can be well organized in graphs. The CPU or bytecode doesn't know about objects anyway. So it's an abstraction and you need to applay that in a moderate fashion, depending on the complexity of the problem, so for simple or efficient procedures imperative style is not to be replaced by OOP. fopen, fread etc. all are abstractions of underying system calls, but depend on speed, so light OOP is a good fit there,
You nailed it.It's just more elegant to group things as a class than having fopen,fread,fclose where you pass a resource as a first argument. Polymorphism then is the consequence of that design since you could have the same interface for a file,a socket,an archive or whatever. When in use,you can ignore the nature of the resource and just remember it can be opened,read or closed,which allows to write abstract logic on top of it.