Arrays and Access types...

[Eric G. Miller <egm2@jps.net>]

New to Ada and trying to figure out how to deal with arbitrary
slices of arrays.  I defined an array type and an access type
for it, but I can't seem to figure out how to take a slice of
the array and assign that slice to an access type.

Type is like:

type My_Array is array (Positive range <>) of Integer;
type My_Array_Ref is access My_Array;

... in body ...

left, right, start : My_Array_Ref;

begin
    start := new My_Array (1 .. 200);
    left  := start(start'first .. 100); -- that doesn't work!
...

The first is allowed, whereas I can't figure out how to
make second an access type assignment (is it possible?).

What I want to do is progressively subset the array, and I
won't know exactly how it'll get broken up until runtime.  The
original array will get divvied up into smaller and smaller
slices of an earlier slice (the remaining can be discarded).

If there's a way to do this with regular arrays (no access
types), that'll work.  I wanted to minimize the number of
"new" arrays -- I'm not quite comfortable with how/when to
use Unconstrained_Deallocation yet...

-- 
Eric G. Miller <egm2@jps.net>