Re: technology discussion → does the world need a "new" C ?

On 16/08/2024 01:08, Ben Bacarisse wrote:

Bart <bc@freeuk.com> writes:
 

On 15/08/2024 15:33, Ben Bacarisse wrote:

Bart <bc@freeuk.com> writes:
>

On 15/08/2024 09:43, Tim Rentsch wrote:

Bart <bc@freeuk.com> writes:

>

                           C call-by-value         call-by-reference
                           ===============         =================
     at call:
>
       (array argument)    F(A)                    H(A)
>
       (pointer argument)  F(p)                    (disallowed)

>
My posts were about passing *arrays* and the fact that C's pass-by-value
was remarkably similar to pass-by-reference.

Which is why, presumably, you didn't show the differences.  Your
post was all polemic not part of a collegiate discussion of the
similarities and differences.
>

However your entry for pointers is not correct:

No, the entry is correct.  H(p) would be (is?) disallowed when H's
parameter is a reference to an array.

>
Sorry, what language does the right-hand column pertain to? /Any/ language
that has call-by-reference, or Tim's hypthetical language?

 Tim said that case was "disallowed".  You call that an error on his
part.  What language did you have in mind that permits such a gross
warping of types?  I would describe /any/ language that allowed it as
having a design error.

You or he would have to go into more detail, such as an actual example, to demonstrate whatever it is that you think is wrong about passing a pointer argument by-reference.
I assume here that the language in the right column is not C.

 

Or any that could be used to prove him right?
>
In general there is no reason, in a language with true call-by-reference,
why any parameter type T (which has the form U*, a pointer to anything),
cannot be passed by reference. It doesn't matter whether U is an array type
or not.

 I can't unravel this.  Take, as a concrete example, C++.  You can't pass
a pointer to function that takes an array passed by reference.  You can,
of course, pass a pointer by reference, but that is neither here nor
there.

OK. So why do you agree with this:
 >>>>>                            C call-by-value         call-by-reference
 >>>>>                            ===============         =================
 >>>>>        (pointer argument)  F(p)                    (disallowed)
What is 'pointer argument' here?