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From: Simon Wright <simon@pushface.org>
Newsgroups: comp.lang.ada
Subject: Re: How to make Ada popular. Get rid of ";" at end of statement.
Date: Fri, 26 Jul 2019 17:07:50 +0100
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Date: 2019-07-26T17:07:50+01:00
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Niklas Holsti <niklas.holsti@tidorum.invalid> writes:

> On 19-07-26 13:54 , antispam@math.uni.wroc.pl wrote:
>> Ingo M. <announce@amkade.com> wrote:

>> So, less restrivtive target language is more convenient for
>> generaator.
>
> I would be afraid that generating the less restrictve language could
> hide and mask bugs in the generator.
>
>> Also, macros in target language simplify generator.  Theoretically
>> you may think that generator can do expansion.  It can, but in
>> practice macros in target language make difference.
>
> Of course there are any number of macro systems that could be used in
> the generator Ada, although Ada has no macro system built in. But
> again, I would be afraid that extensive use of macros in the generated
> code would make it harder to review for generator errors, and could
> also hide inefficient generated code.

There's an unavoidable amount of complication involved in the mapping from
model to executable code. In my experience[1] some of that ends up in
the generator, and some in generics (not that far distant from macros, in
this context) in the runtime support.

In [1] generation is a complex process involving extraction from a model
(UML) to a more amenable form, XSLT stylesheets, makefiles. There's a
great deal of conditionality in the stylesheets; for example, the
difference between a class whose instances are identified by a string
(needs a map) and one whose instances are identified by an enumeration
(needs an array).

In hindsight, I'm not at all sure that using XSLT was the right
long-term solution (it's not at all easy to reason about it).

[1] https://github.com/simonjwright/coldframe