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/* Part of SWI-Prolog
This example code is in the public domain
*/
#include "SWI-cpp2.h"
#include <iostream>
using namespace std;
/* Usage:
likes prints who likes what
likes x prints what is liked by x
likes x y Test whether x likes y
likes -happy See who is happy
Compile using:
swipl-ld -o likes -ld g++ -goal true likes.cpp likes.pl
*/
int
body(int argc, char **argv)
{ if ( argc == 1 )
{ if ( strcmp(argv[0], "-happy") == 0 )
{ PlTermv av(1); /* likes - happy */
cout << "Happy people:" << endl;
PlQuery q("happy", av);
while( q.next_solution() )
cout << "\t" << (char *)av[0] << endl;
} else
{ PlTermv av(2);
cout << argv[0] << " likes:" << endl;
av[0] = argv[0];
PlQuery q("likes", av);
while( q.next_solution() )
cout << "\t" << (char *)av[1] << endl;
}
} else if ( argc == 2 )
{ PlTermv av(2);
av[0] = argv[0];
av[1] = argv[1];
if ( PlCall("likes", av) )
cout << "yes" << endl;
else
cout << "no" << endl;
} else
cout << "Usage: likes x [y] or likes -happy" << endl;
return 0;
}
int
main(int argc, char **argv)
{ PlEngine e(argv[0]);
try
{ return body(argc-1, argv+1);
} catch ( PlException &ex )
{ cerr << (char *) ex << endl;
exit(1);
}
}
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