Re: [Gm2] HALT procedure

[Gaius Mulley]

David Egan Evans <address@hidden> writes:

> The HALT procedure calls the C abort by default, which aborts the
> program abnormally. Though this isn't explicit in PIM, I believe it is
> in ISO/IEC 10514-1 (mainly because of the introduction of the parameter
> for the program return value).
>
> More specifically, I understood that HALT (without parameters) should
> behave as if the end of the program had been reached. This was added to
> compensate for the removal of the GOTO, which in Pascal was typically
> used to go the end of the file.

Hi,

firstly apologies for the delay in replying - I've been in the land of
doom3 and teaching preparation.

I've dug out my pim2, 3, 4 and ISO documents.  It does appear to me
that HALT is designed for abnormal termination.  Even in the PIM
examples XREF etc - the HALT always occurs if a fatal error is reached
(file was not opened) in the XREF example.  Or in the processes
example a runtime problem is detected before HALT is called.

In ISO on page 40 it talks about

>    a) the end of the normal part of the program module 
>       initialization body is reached,
>    b) a RETURN statement is executed in the program module
>       initialization  body,
>    c) the standard procedure HALT is called,
>    d) an exception is raised and this exception is not handled.   

and then goes on to categorise case (a) and (b) as normal termination.
Which I conclude that (c) and (d) are abnormal termination.  So I think
the current implementation is correct - unless I've misunderstood
something?

regards,
Gaius