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The bottom line: use INTEGER as a loop counter. Do not use BYTE
or SHORTINT.
VAR
b : BYTE; i: INTEGER;
i := b;
FOR i := 0 TO MAX(BYTE) DO
On Thu, 22 Jun 2006, Treutwein Bernhard wrote:
> Hi Rex,
>
> [...]
> > >Beware also that the following loops for ever:
> > >
> > >VAR
> > > b : BYTE;
> > >FOR b := 0 TO MAX(BYTE) DO
> >
> > This seems to me like an error in the language
> > specification, but in any case it can be trapped by integer
> > overflow checking, which can be implemented with compiler option '+'.
> >
>
> when I encountered it (years ago), there was no hint
> about how to enable overflow checking ...
>
> The point is: INC(b) returns BYTE as opposed
> to b := b + 1 which produces a compiler error since
> b + 1 is INTEGER. In the latter case you have to explicitely
> use SHORT(SHORT(b+1)) to get it to compile.
>
> At least the possible (silent? by default) loss of digits is
> labeled in the latter case.
>
> regards
> --
> Bernhard Treutwein, IuK, Ref. III A 3
> Bernhard.Treutwein(at)verwaltung uni-muenchen de
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Received on Thu Jun 22 2006 - 16:38:31 UTC