Precision and CD's

[J H Davenport]

>>> > Every bigfloat has a precision attribute.  If it is not
>>> > obvious from its face what its precision is, then it should
>>> > be noted explicitly.  
Odd, I seem to recall some-one saying earlier in this group
::The fact is, every floating point number is an
::EXACT RATIONAL NUMBER. DEAD ON EXACT.  NOT AN INTERVAL. NOT SOME
::KIND OF MYSTERY-FUZZ.   
>>> hmm something not explicit in James' proposed construct in the CD.
>>> It could be added though.
This is precisely why the bigfloat CD does NOT have a precision view.

It would certainly be possible to add more objects to the bigfloat CD,
or create an extending CD which had precision as well, or to do
various other things. However, there are some issues, such as absolute
error versus relative error, which need to be thought about, and there
is also the question of what semantics the precision implies. Do we
even want to suggest the Mathematica semantics?

>>> > Let me repeat:  if the precision of a bigfloat in some representation
>>> > is not apparent, then THAT IS NOT ACCEPTABLE.
I have problems reconciling this with the statement I quoted above.
>>> James, what about adding a fourth child to bigfloat constructor?
As you can probably guess by now, I am not convinced.
I'd certainly want to think about it.
James