Re: OS Bindings (was: Where is the elusive jump command?)

["Tarjei T. Jensen" <tarjei.jensen@kvaerner.com>]

Robert Dewar wrote in message <8cp23c$4gp$1@nnrp1.deja.com>...
>In article <8ck638$krs3@ftp.kvaerner.com>,
>  "Tarjei T. Jensen" <tarjei.jensen@kvaerner.com> wrote:
>> A good example of this is the definitions in the interfaces.C.
>> The unsigned types are really useless and undermines the type
>> safety we should expect from Ada. These definitions fails
>> completely to capture the spirit of the usage in C.
>
>I am completely mystefied by the above, it includes a number
>of very curious assertions, with absolutely no indication of
>the strange theory that must underlie these assertions. From
>where I see things, there is no undermining of type safety in
>these declarations, and they capture the semantics of C
>unsigned types perfectly.

Unsigned in C might have similar semantics to modular types in that there is no
range checking. In C, unsigned types are used for types like size_t NOT because
there is no range checking, but because of the range. max(unsigned) > max(int).
An unsigned type allows for bigger files or whatever than a similar sized
signed value.

In most cases where an unsigned type like size_t is used it is apropriate to
translate it to an unsigned integer of some sort and not a modular type.
Arithmetic operations which causes wraparound are most likely errors and should
be caught.

Now I have to remember to check interface.C when I get home, to check verify
that the definition of int, short and long in gnat has C semantics.

Greetings,