[r6rs-discuss] Validity of nan.0 and inf.0 using a radix other than 10.

[leppie]

Hi

Thanks for the clarification, I however am still unsure which route to 
follow.

> I agree that #e+inf.0 should be an error, and I
> believe that it *is* an error in approximately the
> R5RS sense, which is to say it has unspecified
> behavior with respect to the R6RS:  Implementations
> of the R6RS are not required to raise an exception
> when they encounter #e+inf.0 as a lexical token,
> because it is clearly generated by the lexical
> syntax and there is no clarifying prose to suggest
> that it is illegal or should raise an exception;
> at the same time, implementations should be allowed
> to raise an exception because #e+inf.0 makes no sense.
>

So as the behavoir is unspecified, this leads to a paradox!

- read number (say #e+inf.0)
- if you allow inf.0, then no error, but the number is not exact (and cannot 
possibly be exact), and applying exact to inf.0 yields an exception.
- if you do not allow inf.0, then you raise an exception, and the input is 
deemed invalid.

So either way, it does not make sense.

Cheers

leppie