Re: [Gm2] INTEGER CARDINAL compatibility - little follow up

[Gaius Mulley]

Hi Andreas,

many thanks for clarifying up these queries and also for the manual
and test code.  Yes the code is useful,

regards,
Gaius



Andreas Fischlin <address@hidden> writes:

> Dear Gaius,
> 
> Attached Wirth et al., 1992, the MacMETH manual, may be useful for you
> to look at PIM issues. Lot's is written from the perspective of a
> compiler builder. In case you should be interested, I can give you all
> sources of the MacMETH compiler.
> 
> Note, apart from the 1-pass restrictions and the exotic solution for
> LONGINT, LONGCARD and LONGREAL constants (Ex.: CONST lintc = 2D;
> lrealc = 1.2D-4;). It can also be found at
> http://www.sysecol.ethz.ch/SimSoftware/RAMSES/MacMETH.html
> resp. 
> http://www.sysecol.ethz.ch/SimSoftware/RAMSES/Documents/MacMETH_Manual.pdf
> 
> The other attachment is littel test program that's compilable with our
> latest MacMETH compiler, yet results of course in a run-time error
> towards the end. Should be self eplanatory.
> 
> Regards,
> Andreas
> 
> 
> Cited references:
> ----------------
> Wirth, N., Gutknecht, J., Heiz, W., Schär, H., Seiler, H., Vetterli,
> C. & Fischlin, A., 1992. MacMETH. A fast Modula-2 language system for
> the Apple Macintosh. User Manual. 4th, completely revised ed. User
> Manual Department of Computer Sciences (ETH), Zürich, Switzerland, 116
> pp.
> 
> 
> Gaius Mulley wrote:
> > Hi,
> >
> > I'm in the middle of correcting the compatibility between INTEGERs
> > and CARDINALs during assignment, expression, parameter passing
> > and INC and DEC.  (With appropriate runtime range checking).
> >
> > I see from PIM4 and ISO that mixed expressions using an INTEGER
> > and CARDINAL variable are disallowed.  But I couldn't find whether
> > this also includes:
> >
> > MODULE foo ;
> > VAR
> >    i: INTEGER ;
> >    c: CARDINAL ;
> > BEGIN
> >    IF i>c
> >    THEN
> >
> >    END
> > END foo.
> >
> > from my reading is that this is illegal according to ISO and PIM, but
> > this does seem restrictive..  I was just wondering whether I'd missed
> > something, or misinterpreted something?
> >
> > Conversely its my understanding that:
> >
> > DEC(c, i)    (* legal providing 0 <= i <= MAX(CARDINAL)
> >                 (* the later always true for i *) *)
> >
> > and DEC(i, c)    (* legal providing 0 <= c <= MAX(INTEGER) *)
> >
> >
> > regards,
> > Gaius
> >
> >
> > _______________________________________________
> > gm2 mailing list
> > address@hidden
> > http://lists.nongnu.org/mailman/listinfo/gm2
> >
> 
> -- 
> <pre>________________________________________________________________________
> Andreas Fischlin, Ph.D., Group Director
> 
> Terrestrial Systems Ecology
> Institute of Integrative Biology: Ecology, Evolution, Infectious Disease
> Department of Environmental Sciences, ETH Zurich
> 
> Address:
> ETH Zurich, CHN E35.1
> 8092 Zurich, Switzerland
> 
> Phone: +41 44 633-6090 / Fax: +41 44 633-1031
> http://www.sysecol.ethz.ch/Staff/af/
> http://www.sysecol.ethz.ch/
> 
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>               Make it as simple as possible, but distrust it!
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> </pre>