Re: Bare decorations (was ...level 2 datums)
On 2010-10-25 00:09:10 -0500, Nate Hayes wrote:
> John Pryce wrote:
> >It is possible to discuss Level 2 in the abstract, but there is NO way to
> >define a specific Level 2 floating-point or interval datatype without
> >describing it by some sort of formula, which usually amounts to a
> >representation.
>
> I'm sorry, John, but this is not true.
[...]
I also disagree with John and agree with what Nate said.
Also I'd add that when a representation is described, it does not
necessarily correspond to the Level-3 representation. For instance,
for binary floating-point, one may want to see the significand as
an integer value, not necessarily normalized, even though the L3
representation is different (see the IEEE 754-2008 standard).
> My point was that in IEEE 754 "floating-point data" is Level 2, which is
> then mapped into a Level 3 representation (see quote from 754-2008 in
> previous e-mail). These Level 3 representations are then further mapped into
> computer languages via language bindings. So there are many levels involved:
>
> Level 2: abstract data types (ADT)
> Level 3: representations of ADTs
> Level 4: encodings of representations into bits and bytes
> Level 5: language bindings
I wouldn't see language bindings as "Level 5", but something
orthogonal, which can cover all the levels (and not just the
data, but also the operations and more).
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Vincent Lefèvre <vincent@xxxxxxxxxx> - Web: <http://www.vinc17.net/>
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