[R6RS] safe and unsafe; declarations

[Michael Sperber]

William D Clinger <will at ccs.neu.edu> writes:

> 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.

I'm not sure I understand this now---the main reason, I think is this
talk of exception handlers.  Isn't the R6RS mostly going to specify
what exceptions are *raised*, and leave the handling to the
application?

Anyway, would a correct inference from what you're writing be:

"Anything within the dynamic extent of expressions within the scope of
an unsafe declaration is allowed to do something completely
unspecified whenever it would raise an exception in safe mode."

?

Sorry if I'm being dense---I'm really confused.

-- 
Cheers =8-} Mike
Friede, Völkerverständigung und überhaupt blabla