Re: Prefix to 'ACCESS must either statically match... But why?

["James S. Rogers" <jimmaureenrogers@worldnet.att.net>]

"Wojtek Narczynski" <wojtek@power.com.pl> wrote in message
news:5ad0dd8a.0301280414.6ac8d45e@posting.google.com...
> > Why are you choosing to pass an access to a Stream_Element_Array
> > instead of just the Stream_Element_Array? Avoiding the use of an
> > access type would also eliminate the problem. Remember that any
> > parameter, even an IN parameter can be passed by reference by the
> > compiler. In fact, an array object is most frequently passed by
> > reference.
>
> Because this function uses 'Unrestricted_Access to return an array of
> accecceses to slices of the parameter array. This is supposed to yeld
> in better speed and compactness, and let me avoid heap allocations. If
> I were to copy the strings out of this huge array I'd have to allocate
> them on heap.

Since this is a parameter array, why not merely return an array of
index pairs? The index pairs can index the beginning and end of
each array slice.

The idea of returning a set of "pointers" to pieces of an array is
very common in C, where pointer arithmetic is tied to array
indexing. In Ada there is no corresponding tie between access
types and array indexing. If you want an index, then use an
index. This difference between C and Ada is made easier to
use due to Ada's array slicing capabilities, which are not
directly implemented in C.

>
> >> And in general I find the inablility to declare access type
> >> subtypes in parallel with the subtypes for the designated
> >> type obstructive.
> >
> > It appears that you are thinking in C while programming in Ada.
>
> Heh, maybe. Please take a look at my other post - even the compilers
> are unsure if what I've written is Ada ;-)

Jim Rogers