Re: Syntax for tagged record types (was Re: Not intended for use in medical,)

[jsa@alexandria (Jon S Anthony)]

In article <mheaney-ya023680002305971754170001@news.ni.net> mheaney@ni.net (Matthew Heaney) writes:

> What I am proposing is a new syntax, by adding a constructor abstraction;

Oh.

> File_Type'Open in this example.  (Today, in Ada 95, Text_IO.Open is an
> ordinary procedure.)  It would look something like:
> 
>    constructor Open (Name : String; Mode : File_Mode) return File_Type;
> 
> or maybe
> 
>    constructor File_Type'Open (Name : String; Mode : File_Mode);
> 
> 
> We want to "invoke" the constructor during the elaboration of the File_Type

Oh yeah.  Bob Duff and I went 'round and 'round on this issue a few
months back.  Actually, maybe it was all the way back in the Fall.
Specifically, it concerned why an allocator for a limited type was
defined in terms of assignment when it was given an aggregate.  Bob
generalized the issue to say that, well, for limited types you should
simply be able to initialize them other than by assignment and then
this special case would be OK as well.  Then someone posted a bit from
the Annotated RM which got even more to the point that I was trying to
say: for a limited type the _value_ is basically all there is (no
variable really at all).  Anyway, at that point, we all let the air
out of our shoes and went home.

/Jon
-- 
Jon Anthony
Organon Motives, Inc.
Belmont, MA 02178
617.484.3383
jsa@organon.com