Re: [ANN] an EBNF parser and coding pattern tool (LGPL)

[Stephen Leake <Stephen.A.Leake@nasa.gov>]

Hyman Rosen <hyrosen@mail.com> writes:

> When things are known at compile time, they can be generated
> at compile time. You need to read up on what's being done in
> the world of C++ templates. Here's a cursory synopsis:
> 
>      struct Nil { };
> 
>      template <typename T1, typename T2>
>      struct TList
>      {
>          typedef T1 first;
>          typedef T2 rest;
>      };
> 
> Now, given an arbitrary class, like
> 
>      struct A { int a; double c; char *p; };
> 
> I could reasonably ask the compiler to provide me with
> 
>      Introspect<A>::FieldTypes
> 
> which would be a typedef for
> 
>      TList<int, TList<double, TList<char *, Nil> > >
> 

That makes sense, assuming "Introspect" and "FieldTypes" are new C++
keywords. Are there any C++ compilers that actually do this? I don't
think it's in the current ISO C++ standard.

Is there anything preventing the same techniques in Ada? (assuming we
allow new keywords).

How does this compare with an ASIS tool for Ada? Seems to me ASIS is a
more straight-forward, and more flexible, approach.

> <snip rest>

-- 
-- Stephe