[R6RS] safe and unsafe; declarations

[William D Clinger]

Mike wrote:
> > At priority 0, an implementation is allowed to use exception
> > handlers that ignore even required exceptions and continue
> > the computation with an incorrect result, or to use handlers
> > that terminate the computation in an unpleasant fashion.
> 
> Does this mean that an implementation is free to do this for all
> situations where R6RS describes that an exception must be raised, or
> will the text something along the lines of "at safety priority 0, all
> bets are off" for specific situations, and all places that don't have
> it will still be required to raise exceptions?

You spotted a bug in the wording.  My intent was that an
implementation would be allowed to use arbitrarily perverse
exception handlers for all exceptions, not just those
exceptions required by the R6RS.

We really don't want to get into the business of telling
implementors what their unsafe mode does and doesn't do.
That hole is deep and dark.

Will