Re: about inheritance of subtypes and entities (such as constants) related to a type in the same package

["Randy Brukardt" <randy@rrsoftware.com>]

"Dan'l Miller" <optikos@verizon.net> wrote in message 
news:c6b68b0d-e9f0-47a8-9692-7cba63ea1000@googlegroups.com...
On Tuesday, May 29, 2018 at 5:12:23 PM UTC-5, Randy Brukardt wrote:
...
>> long before
>> anyone really understood OOP or similar systems.
>
>Well, there was Simula in the 1960s.

Yes, I know that. But hardly anyone understood them. I recall studying 
Simula at the University of Wisconsin in the programming language class, and 
the textbook and instructors presented it as an interesting diversion from 
typical programming. (We also studied Planner and CLU in that class, along 
with more mainstream things like Lisp.) No one guessed then that a 
substantial branch of programming was going to grow out it.

Regardless of whether Ada 83 called the derived type mechanism 
"inheritance", it surely was that, and it survives virtually unchanged for 
all types in Ada 95 and later. Some additional stuff was added to it 
(especially for tagged types), and some details were nailed down better, but 
the mechanisms for subprograms in particular are identical. I thought that 
was a problem during the development of Ada 9x; no one understood derived 
types at all in Ada 83, and building the entire OOP system on top of them 
seemed like elevating an obscure bar band to the main stage at Summerfest. 
Luckily, I was mostly wrong about that.

                                                           Randy.


                               Randy.