Re: Studying and Maintaining GNAT, Is There Any Interest in a New Group?

[AdaMagica <christ-usch.grein@t-online.de>]

Am Sonntag, 2. September 2018 14:10:36 UTC+2 schrieb Jeffrey R. Carter:
> On 09/02/2018 12:11 PM, AdaMagica wrote:
> > Am Samstag, 1. September 2018 00:51:42 UTC+2 schrieb Randy Brukardt:
> >> Similarly, in Ada 2012:
> >>      Ren1 : Natural renames Func(1); -- Legal.
> >>      Ren2 : Natural renames Natural'(Func(1)); -- Legal.
> >>      Ren3 : Natural renames Natural(Func(1)); -- Illegal!!!
> >>
> >> At least Ada 2020 will fix this one. But try this:
> >>       Ren4 : Boolean renames Boolean'(A and B); -- Legal.
> >>       Ren5 : Boolean renames Boolean'(A and then B); -- Illegal.
> >>       Ren6 : Boolean renames "and"(A, B); -- Legal.
> >>       Ren7 : Boolean renames A and B; -- Illegal.
> > 
> > Ahem, perhaps my Gnat 2018 is not correct, but it rejects only Ren7, which is an expression, and that cannot be renamed according to syntax.
> 
> FSF GNAT 8.0.1 rejects all 3:
> 
> $ gnatmake renaming.ads
> gcc-8 -c renaming.ads
> renaming.ads:9:27: renaming of conversion only allowed for tagged types
> renaming.ads:11:34: expect object name in renaming
I guess this is Ren5.
Why should Ren4 be legal? Also "A and B" is an expression, not an object.
"and"(A,B) is a function call, thus an object, whereas infix "and" in Ren4 is not a function call, but an expression.

Ah, I found AARM 6.4(3.a/3). This makes Ren4 legal.
So of course "and then" not being an operator, the expression in Ren5 is not considered a function call.

Truly bizarre rules.