Re: [prolog-standard] Re: log10/1, log/2, min/2, and max/2

On 2006/11/16, at 19:39, Jan Wielemaker wrote:

> On Thursday 16 November 2006 19:37, Paulo Moura wrote:
>>> Why is this desirable, when it leads to the problems indicated?
>>> After all, this is an arithmetic function, so there is no reason
>>> why it should not use the same floating-point contagion rule
>>> like all other symmetric binary operations,
>>
>> Agree.
>
> First of all, in practice min and max are rarely used with mixed
> types.

If that's true then...

> Second, most implementations providing unbounded integer arithmetic do
> not provide unbounded floats, so max(2<<10000, 2.0)

... this example is meaningless as it uses mixed types, correct? :-)

> raises an error if
> we promote the floats. Before that you may loose acuracy in the
> unnecessary promotion to float. Select semantics avoids all these
> problems.

Cheers,

Paulo

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Paulo Jorge Lopes de Moura
Dep. of Computer Science, University of Beira Interior
6201-001 Covilhã, Portugal

Office 4.3 Ext. 3257
Phone: +351 275319891 Fax: +351 275319899
Email: <mailto:pmoura_at_di.ubi.pt>

Home page: <http://www.di.ubi.pt/~pmoura>
Research: <http://logtalk.org/>
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Received on Mon Jul 14 2008 - 13:01:02 EST