Re: Garbage collection (was a spinoff of a spinoff of a GA diatribe)

[dewar@merv.cs.nyu.edu (Robert Dewar)]

Wes says

"And with composites, the provider of the data type has the complete freedom
of choice to extend a controlled type with GC, extend a controlled type
without GC, or not use a controlled type.

So, compared to the above, how big is the payoff of having GC imposed on
you by the implementation?"


I don't think it is quite that simple. There is nothing to prevent a
compiler having a temporary copy of a pointer to some controlled object
in a register if this would not normally be detectable by as-if semantics.
Perhaps one can do a simple collector, but certainly a compacting collector
raises question marks.

Even the simple collector is not so simple as far as we can tell. If someone
thinks it is trivial, and would like to contribute a garbage collected pool
that really works to the Ada community, that would be very welcome!