Re: Java vs Ada 95 (Was Re: Once again, Ada absent from DoD SBIR solicitation)

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

Dave says

"As I understand it (I might be wrong.), the Ada95 standard does not
include true garbage collection, but, instead, it has something called
garbage reduction.  Garbage reduction, apparently, is not as efficient
as garbage collection, and, I am told, you risk filling up memory if you
rely on it for a large, complex application.

I am very pleased to see that Intermetrics has developed a true garbage
collector for Ada95.  Can this be used as a third-party product to add
garbage collection to any Ada95 system.  If so, then quite a few
companies would be wise to reconsider Ada95 before starting their next
project."


First, you are wrong, completely! I have no idea what garbage reduction
might be, but in any case, the Ada language is neutral wrt garbage collection,
as, for that matter, is Java from a formal point of view. The whole point
of gc is that it has no semantics, it is transparent!

Any language that translates into JBC will naturally inherit the garbage
collection capability used when Java compiles to JBC. Remember, garbage
collection is NOT part of a language, it is part of an implementation.
This means that thre is no question of using the intermetrics garbage
collection in other contexts, since Intermetrics has not "developed a
true garbage collector", they are merely, quite reasonably, borrowing
the JBC collector. Any other Ada compiler that generated JBC would
inherit the same capability.

It is of course possible to add garbage collection to other Ada
compilers. Whether this is indeed desirable remains to be seen. Garbage
collection has never made it into a mainstream language before for all
sorts of reasons, but it seems quite possible that java will change this.
Of ccourse we won't really know till Java compilers appear, which should
be pretty soon now.