interval_arithmetic enhacements

[mlliarm]

The enhacements of interval_arithmetic implementation.

[mlliarm]

Implemented mid, wid, abs predicates for an interval X = [Xa, Xb].

[mlliarm]

Wanted to replace my way of finding the min and the max of those numbers in the mul/3 predicate, by using min_list and max_list (see [1], [2]) from SWI-Prolog.

Didn't use them though because I was getting some warnings that min_list wasn't defined:

Unknown predicate called but not defined: min_list/2
*       while compiling object interval_arithmetic
*       in file /home/milia/Documents/dev/logtalk/ia/interval_arithmetic.lgt between lines 23-28
*     Calls to unknown and undefined predicates generate a runtime error.
*     Misspelt predicate name? Wrong number of arguments?
*     
*     Unknown predicate called but not defined: min_list/2
*       while compiling object interval_arithmetic
*       in file /home/milia/Documents/dev/logtalk/ia/interval_arithmetic.lgt between lines 23-28
*     Calls to unknown and undefined predicates generate a runtime error.
*     Misspelt predicate name? Wrong number of arguments?

Also, since these predicates are defined in SWI-Prolog, my library could turn out not to be portable to other Prologs out there.

So, sticking with the old dirty way of finding the min(a,b,c,d): min(min(a,b), min(c,d)). Same for max.

[pmoura]

Use the Logtalk library instead. That will give you the same functionality but in a portable way. See https://logtalk.org/library/numberlistp_0.html

[pmoura]

Note that min_list/2 and max_list/2 are library predicates (which you're not importing into the object), not built-in predicates (which would be recognized by the Logtalk compiler as always available).

[mlliarm]

Thanks Paulo ! I'll use the built-in Logtalk library then !