Re: Concatenation and Characters

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

Justin Birtwell wrote:
> Oh,
> 
> N:Natural;
> S:String(1..N);  Doesn't give me a compile error.  Any ideas why?

Becasue evaluating an uninitialized variable is only a bounded error,
which is handled at run-time.  The code is allowed to do one of a small
list of things which includes: raise a run-time exception or use
what ever junk value is found there.  The compiler is allow to, but does
not have to, warn you about the use of uninitialized variables, beceause
in the general case determining this at compile time is equilivant to
solving the halting problem.

I your case it is likely that your compiler did the second thing above:
used the junk value (very likely 0) and thus S was too small (N needs to
be at least 6 for your example to work) and thus you get a CE.


-- 
Mark Biggar
mark.a.biggar@attbi.com