14: adda/oop/type-specific heaps:
[29: intro:
. in a type-specific heap,
each object reference has 2 parts:
# an ID of the type it belongs to,
# a serial number unique to that type . 31:
. this promotes encapsulation,
because the reference isn't a pointer,
the only one who knows the object's address
is the type mgt that owns the object .
]
. given the idea of type-specific heaps,
how does that mix with adda's oop?
--that's the efficient form of oop;
the inefficient way of doing oop
uses garbage collection
and that is a choice independent of
which heap an object is owned by,
whether local or global .
. using pointers is not what causes
pointer semantics and garbage:
that's caused when assignments are overwriting
the pointer instead of the pointer's target:
to avoid garbage collection,
assignments need to overwrite the objects themselves
not the pointers to the objects .
. instead of a global type-specific heap
local vars would be placed into
the subprogram's local heap
that can have within it type-specific subheaps .
