Re: on using array index, vectorized operation

[Phil Clayton <phil.clayton@lineone.net>]

On Mar 27, 11:00 pm, "Nasser M. Abbasi" <n...@12000.org> wrote:
> Only problem now is that I need to figure the castings I need
> to do to make the compile happy, Since now I get the error:
>
> $ gnatmake foo.adb
> gcc-4.4 -c foo.adb
> foo.adb:10:14: there is no applicable operator "-" for type "buffer_t" defined at line 2
> gnatmake: "foo.adb" compilation error
> $
>
> Will look at this now, how best to solve this? I understand
> that it want me to define a "-" operator for buffer_t. I really do
> not want to cast things, I need to find the best solution to this.
>
> May be I need to define a function "-" for buffer_t ?

(So please ignore my previous question.)

I had a similar quandary a few years ago where it was necessary to
describe results of vectorized operations (from Simulink as it
happens) using a language that had no natural support for
vectorization.  The thought of defining variants of operations to work
on 1-D arrays, another set of variants for 2-D arrays etc. was too
horrendous.  It was far simpler to promote scalar operations using a
loop, like in your example.  (We actually produced a vectorized meta-
notation that allowed an expression form of loop like 'for-aggregates'
that I've mentioned before, so didn't need to deal with temporary
variables.)  My advice would be to stick to the loop version, with
temporary variables if necessary, as that is most traceable to the
original text and surely the most maintainable.

Phil



> But I am happy now that at least I can avoid explicit loops if needed.