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

On 11/07/2024 00:01, Ben Bacarisse wrote:

bart <bc@freeuk.com> writes:
 

On 10/07/2024 14:32, Ben Bacarisse wrote:

I still consider arrays in C to be 'passed' by a
mechanism which is near-indistinguishable from actual
pass-by-reference.

 I don't really care how you consider it, but I do care about how you
misrepresent the facts in public.
 In another post you said that your language has pass by reference, and
we also know you have implemented C.  Either you are just very confused
and your language simply has call by value (after all, you think C has
pass by reference), or you know that pass by reference in your language
needs something from the implementation that was not needed when you
implemented C.  I can't decide if you are confused or just lying.

The way it works in my language is very simple (this is what I do after all):
     type T = int
     proc F(T x)=       # Pass by value
         println x.typestr
     end
     proc G(ref T x)=   # Manual pass-by-reference
         println x^.typestr
     end
     proc H(T &x)=      # Auto pass-by-reference
         println x.typestr
     end
     proc main=
         T a
         F(a)
         G(&a)
         H(a)
     end
I've written 3 functions using pass-by-value, pass-by-value emulating pass-by-reference, and actual pass-by-reference.
The G function and the call to G show what the compiler has to add when it processes function H: address-of ops and derefs. The cost is a single & in the parameter list to get that convenience.
This programs works just the same if T was changed to an array:
     type T = [4]int
(The output is 3 lots of '[4]i64' instead of 3 lots of 'i64'; 'int' is an alias for int64/i64.)
This is regular and orthogonal, a complete contrast to C even though both languages supposedly operate at the same level.
The behaviour of F, when written in C, is like my F function when T is an int (obviously the C won't have '.typestr').
But when T is an array, its behaviour is more like that of my H function.
So, my remark about arrays in C being passed by reference is understandable.

If somebody had proposed adding pass-by-reference for arrays, you'd say C
doesn't need it, because whatever benefits it might have you, C already
has!

 I see you are running out of statements to argue against so you have
started to make up your own.  I am sure you have thoroughly refuted this
made up person in your head.
 Anyone proposing adding pass-by-reference for arrays would be told (by
me at last) to start by allowing arrays to be passed by value first.
Why anyone would propose adding pass by reference for a type that can't
be currently be passed at all is a mystery that only you (as the
inventor of this person) can know.

This is my point. Clearly true pass-by-reference for arrays wouldn't add anything in C; it already works alike that! But due to complicated set of rules and quirks, which quite different from the type model illustrated above.