The technical difference is lack of language-level module support, requiring manual management of vtables. It can be done, see Linux kernel for an example, but often times degenerates in a ball of globals.
To further clarify, one can use DOP style in many languages, including languages that are ostensibly OO. DOP is a style, using data hiding and polymorphism as sparingly as possible, as opposed to OOP style, which strongly encourages using data hiding and polymorphism at every corner.
Okay so it just sounds to me like careful OOP. Discipline just isn't a paradigm. It's an ethic and it's a good ethic. I love OOP, I've always built systems I was proud of with it. But to do that effectively you do need discipline and you need experience in design. Which most people think they can just skirt blindly by writing procedural code in class wrappers and the system will just magically emerge. This results in even more horrific programs when combined with blind TDD. This has always been nonsense. I don't use much OOP nowadays due to my work prioritizing efficiency and speed. Which OOP fails at miserably. But every now and again I'll find myself doing some monomorphism that looks like vtable dispatch without ever touching heap. And I'll kindly look back on my OOP days.
Agreed. Careful/Restrained OOP / 95% FP [the ML branch] / DOP, all names for the same sweet spot. The push back is against hard OOP culture, rooted in confused thinking.
* Everything is emphatically NOT an object. There is immutable data, there are functions and there are modules. These are not the interchangeable, learn to use them in the proper context.
* Everything is emphatically NOT a message. There are plain functions, there are polymorphic functions, there are RPCs and there are async messages. These are not interchangeable, learn to use them in the proper context.
To further clarify, one can use DOP style in many languages, including languages that are ostensibly OO. DOP is a style, using data hiding and polymorphism as sparingly as possible, as opposed to OOP style, which strongly encourages using data hiding and polymorphism at every corner.