Re: Latest suggestion for 202x

[Bill Findlay <findlaybill@blueyonder.co.uk>]

On 22 Jun 2019, Keith Thompson wrote
(in article <lnr27likgv.fsf@kst-u.example.com>):

> "Dmitry A. Kazakov"<mailbox@dmitry-kazakov.de>  writes:
> > On 2019-06-21 22:24, Keith Thompson wrote:
> > > "Dmitry A. Kazakov"<mailbox@dmitry-kazakov.de>  writes:
> > > > On 2019-06-21 20:12, Keith Thompson wrote:
> > > > > I *can't* replace A by a function without modifying the code that uses
> > > > > it.
> > > >
> > > > In short if I can't do something then I don't need it, sour grapes...
> > > >
> > > > > I suppose containers weaken that argument
> > > >
> > > > No, it is no argument regardless.
> > > >
> > > > If Ada has problems with array abstraction, and it has, that is
> > > > irrelevant to the point that this is the *same* abstraction.
> > > >
> > > > A language that syntactically distinguish array calls and function calls
> > > > breaks the abstraction or lacks it completely.
> > >
> > > Is breaking that abstraction such a bad thing?
> >
> > Yes, because abstraction is useful. Arrays have no "physical"
> > meaning. It is always an artifact of software design, some
> > implementation detail, not to expose.
> >
> > > Why *should* array
> > > indexing and function calls be treated as the same thing?
> >
> > Because they model the same thing, a mapping, when arrays come in
> > consideration.
>
> I disagree. Array indexing operations refer to elements of an array
> object. Function calls yield a value, and can have side effects.

They are not exactly the same, but similar enough.
This is/was known as "uniform referent notation".
I take the pragmatic view that it can be very handy.

> > > What about record component selection?
> >
> > Same. It is not mapping of ordered 1st class object to 1st class
> > object in this case, but surely the syntax sugar of record member
> > selection must be same for records and functions. And it is, since Ada
> > 2005 started to support dotted notation:
> >
> > R.X -- Record member *or* call to primitive X of R or ...
>
> So would you prefer "R.X" to be written as "R(X)" (or perhaps "X(R)")?

X(R) is exactly how it was written in ALGOL W
(to get a field of the record pointed to by R,
as there were no off-heap records).

In Pascal f^ could be either data in the buffer
of file f or data referenced by a pointer f.
When I converted some s/w from 1900 Pascal to 2900 Pascal,
all the accesses to filed data became accesses to data
in virtual memory without changing the source code.

-- 
Bill Findlay