It would be very helpful if all the errors while interpreting were represented with line numbers.

For example, consider a simple script with a "MessageNotUnderstood" error:

| foo |
foo := 5, 'bar'

The virtual machine gives an error like this:

Object: 2 error: did not understand #,
MessageNotUnderstood(Exception)>>signal
SmallInteger(Object)>>doesNotUnderstand: #,
UndefinedObject>>executeStatements

The following code produces exceptions as below in bursts after a few seconds. More generally, it seems Delay starts failing in situations where the system is somewhat loaded (such as during the event- and render-loops in our SDL/cairo bindings-in-progress).

Code:

Object subclass: DelayExperiment [
    run [
        [ (Delay forMilliseconds: 1) wait ] repeat.
    ]
].
DelayExperiment new run.

Expected output: nothing, forever.

Actual output:

$ gst delay-bug.st
"Global garbage collection... done"
Object: nil error: did not understand #goodness:

When you run TerminationExperiment's #run, it can sometimes reach several tens of thousands of iterations of busyLoop before faulting, but will often fault before 20,000 iterations have completed on my machine.

When you run #run2, things behave as I would have expected them to behave. No faulting occurs, and the process is sensibly terminated.

Here's a selection of some of the faults I see from #run after several seconds. Each comes at the end of a single run of the script, as attached.

Object: '' error: Invalid argument : must be a SmallInteger

ObjectMemory class >> snapshot: does not provide any way to determine whether, at the return from #snapshot:, we are running in

1. the parent, just after the save, or
2. the saved image, just after the load

A good solution to this would be to return some indicator of which image-instance we're running in from #snapshot:.

Given such an indicator, we could build a #snapshot:andQuit: message, a la Squeak, which would provide a convenient way of saving a snapshot and quitting, without having to jump through hoops on resume to determine which actions to take next.