=========== Is UBL feasible?===================
The short answer is yes. I already have the prototype up and running in VC++ 7.1. The 8-queen problem takes less than 28 seconds on my Athlon 2200+ to find all answers.
How much does the plain prolog version take on the same hardware? I assume the motivation for using C++ is a speed-up? And how many lines of code was the C++ version compared to the prolog one? Is there a native C or C++ solution to the 8 queen problem for comparison?
2. syntax wise UBL predicates are not as straight-forward or visually appealing as the equivalent predicates in Prolog. [Example included at bottom]
I think you will have an uphill battle to persuade people to use the library because of this. Is a compiler or macro feasible to allow me to write the prolog one liner and have it turned into the C++ equivalent. (I don't use prolog but could understand and appreciate the prolog code example.) Darren Here is a predicate in
UBL:
BOOST_UBL_PREDICATE_2_( is_grandfather_of, Person, Person ) { BOOST_UBL_VARIABLES_3 ( Person, X , Person, Y , Person, Z );
typedef clause< LHS<X, Y> , is_father_of< X, Z > , is_father_of< Z, Y >
type; };
Here is the equivalent predicates in Prolog:
is_grandfather_of(X, Y) :- is_father_of(X, Z), is_father_of( Z, Y).