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Re: Difficulties in implementation of textToInterval(s)

Folks

Am 24.05.2016 um 08:20 schrieb John Pryce:

P1788.1 members


On 24 May 2016, at 05:02, Dmitry Nadezhin <dmitry.nadezhin@xxxxxxxxxx> wrote:
Michel,


That's an issue for full 1788 (where we have rational literals).  It does
not arise in 1788.1 where all implementations use (or appear to use) b64
endpoints.

I should be more clear. I consider interchanging between 1788 and 1788.1 .
A program in 1788 computes and outputs result for further processing by
other programs without knowledge which interval datatypes are native for other program.
The first program doesn't want to loose precision in conversions.
So it outputs interval literals by s=intervalToExact(x).
If datatype of the first program contains intervals with rational ends,
it will outputs interval literals with rational number literals.

Some of the second programs are in 1788.1 .
They should be able to read the output of the first program containing rational number literals.

Apart from the technical issues there's a point of principle. Should a simplified version of a standard be able to *read* (even if it can't write) external, i.e. text, forms of objects written by the full standard?

NO

Jürgen



It's not obvious to me that the pros of this outweigh the cons, and it's up to Dima to convince us.

If we accept it now it might be a burden in the future. E.g. suppose the next revision decides P1788 shall be able to *read & write* interval endpoints in a continued fraction syntax, does that impose an obligation on P1788.1 to *read* them in that form?

John Pryce