Question

I have a Prolog file (Hanoi.pl) containing the code for solving the Hanoi Towers puzzle:

hanoi( N ):-
    move( N, left, middle, right ).

move( 0, _, _, _ ):-
    !.

move( N, A, B, C ):-
    M is N-1,
    move( M, A, C, B ),
    inform( A, B ),
    move( M, C, B, A ).

inform( X, Y ):-
    write( 'move a disk from ' ),
write( X ),
write( ' to ' ),
writeln( Y ).

I also have a C++ file written in VS2008 IDE:

#include <iostream>
#include <string>
#include <stdio.h>
#include <stdlib.h>
using namespace std;
#include "SWI-cpp.h"
#include "SWI-Prolog.h"

predicate_t phanoi;
term_t t0;

int main(int argc, char** argv)
{
    long n = 5;
    int rval;

    if ( !PL_initialise(1, argv) )
        PL_halt(1);

    PL_put_integer( t0, n );

    phanoi = PL_predicate( "hanoi", 1, NULL );

    rval = PL_call_predicate( NULL, PL_Q_NORMAL, phanoi, t0 );

    system( "PAUSE" );
}

How can I consult my Prolog source code (Hanoi.pl) from within my C++ code? Not from the Command Prompt – from the code, something like include or consult or compile? It is located in the same folder as my cpp file.

Thanks,

Answer 1

My Prolog Source Code (hanoi.pl)

hanoi( N ):- 
    move( N, left, middle, right ).

move( 0, _, _, _ ):- 
    !.

move( N, A, B, C ):- 
    M is N-1, 
    move( M, A, C, B ), 
    inform( A, B ), 
    move( M, C, B, A ).

inform( X, Y ):- 
    write( 'move a disk from ' ), 
    write( X ), 
    write( ' to ' ), 
    writeln( Y ). 

My C++ Code (written in VS2008 IDE)

#include <iostream>
#include <fstream>
#include <string>
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdafx.h>
using namespace std;
#include "Windows.h"
#include "ctype.h"
#include "SWI-cpp.h"
#include "SWI-Prolog.h"
#include "SWI-Stream.h"

term_t t;
predicate_t p;

int main( int argc, char** argv )
{
    argc = 4;

    argv[0] = "libpl.dll";
    argv[1] = "-G32m";
    argv[2] = "-L32m";
    argv[3] = "-T32m";

    PL_initialise(argc, argv);

    if ( !PL_initialise(argc, argv) )
        PL_halt(1);

    PlCall( "consult(swi('plwin.rc'))" );
    PlCall( "consult('hanoi.pl')" );

    int rval;
    long n = 3;
    PL_put_integer( t, n );
    p = PL_predicate( "hanoi", 1, NULL );
    rval = PL_call_predicate( NULL, PL_Q_NORMAL, p, t );

    PL_halt( PL_toplevel() ? 0 : 1 );
}

Just press F5 in VS2008 to build and compile and run!