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From: "Randy Brukardt" <randy@rrsoftware.com>
Newsgroups: comp.lang.ada
Subject: Re: Ichbiah 2022 compiler mode
Date: Sat, 14 Sep 2024 01:18:25 -0500
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"Lawrence D'Oliveiro" <ldo@nz.invalid> wrote in message 
news:vbvpmt$esm6$7@dont-email.me...
> On Wed, 11 Sep 2024 23:39:27 -0500, Randy Brukardt wrote:
>
>> "Lawrence D'Oliveiro" <ldo@nz.invalid> wrote in message
>> news:vbdk2t$hj0r$6@dont-email.me...
>>> On Thu, 5 Sep 2024 19:03:22 -0500, Randy Brukardt wrote:
>> ...
>>>> (10) Variable-returning functions are introduced.
>>>
>>> Is this like updater functions in POP-11, or "setf" in Lisp?
>>
>> No, it is a function that returns a variable, meaning you can assign
>> into the function result.
>
> I think an updater function would be more generally useful. Because some
> things you want to update might not (depending on the implementation) live
> independently in an explicit variable. And it seems good not to constrain
> implementations unnecessarily.

Unfortunately, "updater" functions don't work with the Ada model of 
components, because you can't tell what to do when a component appears or 
disappears in an assignment. (That's why Ada doesn't allow overloading 
":=".) And composition is very important to Ada -- stand-alone objects are 
pretty rare outside of those for scalar types. I don't think something that 
only worked with stand-alone objects would be very useful (can't use those 
with ODTs, for instance)..

                  Randy.