BP OOP problem
Prof A Olowofoyeku (The African Chief)
chiefsoft at bigfoot.com
Tue May 18 21:53:20 CEST 2004
On 18 May 2004 at 4:03, Frank Heckenbach wrote:
> I just found another problem in BP's OOP. In the following program,
> `o.f' in oo.p is ambiguous. It could mean field f of the field o, or
> function f of the parent type o. Both BP and GPC (currently) do the
> former (i.e., say 99).
> I noticed this because the OOE draft forbids this case by requiring that
> object fields don't clash with parent type names.
> We do we do here? Allow it in BP mode with a warning, error
> program Foo;
> o = object
> function f: Integer;
> oo = object (o)
> o: record
> f: Integer
> procedure p;
> function o.f: Integer;
> f := 42
> procedure oo.p;
> WriteLn (o.f)
> v: oo;
> v.o.f := 99;
This looks okay to me (i.e., I would expect "99"). The "Writeln (o.f)"
clearly refers to the "f" field of the record "o". The fact that it is
qualified makes it clear (to me at least). It could not possible refer
to the function "f" in the parent object, because using the base name
of the parent object in this manner must generate a compiler error.
On the other hand, "Writeln (f)" would refer to the function "f" in the
parent object. In other words, I don't see any ambiguity here - and
neither does the compiler, because, in fact, there is no ambiguity.
Best regards, The Chief
Prof. Abimbola A. Olowofoyeku (The African Chief)
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