Programming in the large with prolog

Question

I'm trying to keep my Prolog code modular, and I was wondering if anyone had any advice as to how to do this. The way I was doing this with simple consults, but that is getting cumbersome as the number of my files increase and succumbs to name clashes. Is there any construct similar to that of a "typical" import, such as

%-------------------------------------------------------------------- compiler.pl

[ scanner, parser, codegen ] .

%-------------------------------------------------------------------- compile

% compile( S, I ) :- Compiling the source string S gives the list of instructions
%                    I

compile( S, I ) :- scan( S, T ), parse( T, A ), codegen( A, I ) .

%-------------------------------------------------------------------------------%

at the top of a source file? If it is program specific, I'm using gprolog. Thanks in advance for any help.

Answer 1

GNU-Prolog does not have a genuine module system, so your approach is currently the best you can get. Maybe GNU-Prolog might add a module system in the future, but I would not bet a business on it.

The most frequent module system permits to define in different modules predicates with the same predicate name and arity. Thereby name clashes of predicates are avoided. Atoms and functors remain the same over module boundaries. Systems like SICStus, YAP, SWI, Ciao, IF and the ISO standard have such a system.

Another kind of module system is offered by XSB - called functor based.