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

[Andreas Fischlin]

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:
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8092 Zurich, Switzerland

Phone: +41 44 633-6090 / Fax: +41 44 633-1031
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http://www.sysecol.ethz.ch/

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 _/_/_/   _/   _/  _/   Politecnico federale de Zurigo

             Make it as simple as possible, but distrust it!
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MacMETH_Manual.pdf
Description: Adobe PDF document

TestDec.MOD.zip
Description: application/applefile