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

On 16/08/2024 01:08, Ben Bacarisse wrote:
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Bart <bc@freeuk.com> writes:
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On 15/08/2024 15:33, Ben Bacarisse wrote:
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Bart <bc@freeuk.com> writes:
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On 15/08/2024 09:43, Tim Rentsch wrote:
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Bart <bc@freeuk.com> writes:
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                           C call-by-value         call-by-reference
                           ===============         =================
     at call:
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       (array argument)    F(A)                    H(A)
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       (pointer argument)  F(p)                    (disallowed)

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

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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.
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However your entry for pointers is not correct:

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

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

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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.

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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.
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I assume here that the language in the right column is not C.
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Or any that could be used to prove him right?
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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.

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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.

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

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What is 'pointer argument' here?