Re: Compile time executed functions

[Mark Biggar <mark.a.biggar@home.com>]

Ted Dennison wrote:
> 
> In article <3AC2EE4D.56D61A58@mida.se>, Mats Karlssohn says...
> >
> >function (better probably to limit its ability to loop though).
> 
> Of the 3 approaches I mentioned, I think this one (allowing it, but limiting it
> so that infinte loops cannot be written) would probably be the most promising.
> It would be a fair bit of work though. It'd be interesting to see some graduate
> student do a thesis or disseration on this subject. It should be fairly possible
> to build someting of this sort off of Gnat.

It's been done many times.  For example go read "Godel, Esher and
Bach" by Hofsteder, the section on the *LOOP languages.  Obviously you
must outlaw abritrary "goto" statements, recursive procedures and
while loops, but if (case) statements and Ada like "for" loops are fine.
The trick it that you can only have looping construsts that allow
the computation of a strict bound on the number of iterations, 
before the loop is entered.

--
Mark Biggar
mark.biggar@trustedsyslabs.cpm