OpenEuphoria

Re: Request for feature

• Posted by Pete Lomax <petelomax at ?luey?nder.co.uk> Dec 27, 2007
• 479 views

CChris wrote:
> Sure, abort() is here already, so let's extend it:
> * abort(msg_string) would display msg_string and do an abort(-1);
> * abort({string,ret_val}) would display msg_string and do an abort(ret_val).
>
> How about that?

You may have missed the point about the ex.err?

My take: In the simple case, program A is run stand-alone:

abort(n)     terminates the program quietly, no ex.err, as now.
abort("msg") terminates the program much as ?9/0. Currently it does almost 
              _exactly_ what is desired except that the ex.err contains
              "argument to abort() must be an atom", and it seems logical
              to replace that with "msg" (a tiny change?). [see also PS]

The other case to consider is when program B performs an exec or system_exec of
program A and determines the exit code. Four possibilities now present:

1) normal termination or abort(0).
2) a standard error such as divide by zero.
3) abort(n) where n!=0.
4) [new] abort("msg").

The first point that strikes me here is that program B can only distinguish
abort(1) from case 2) by looking for the presence/date&timestamp/contents of
ex.err. FWIW, I don't see any pressing need for B to treat 4) and 2) any
different if B is not going to examine the ex.err for more details anyway,
but I have no problem with abort({"msg",code}) if others really want it.

If I got everything right, I too support this change.

Regards,
Pete
PS for those of you unaware of this, try running the following code:

procedure x()
abort("some possibly quite helpful message")
end procedure
x()

The key point is the ex.err contains "called from line 4", ie it is a run-time
not a compile-time error as things [already] stand.

PPS Actually, there is a weakish argument against abort({"file in use",4}) if
program B decides that 4 means "file not found" or some completely different
error. Worse, it may encourage B to maintain a table of strings which can easily
get wildly out of step.