private static IRule parseRule(String program) throws ParserException {
assert program != null;
final Parser parser = new Parser();
parser.parse(program);
assert parser.getRules().size() == 1;
return parser.getRules().get(0);
}
public static void main(String[] args) throws Exception {
if (args.length < 1) {
System.err.println("Please give directory path.");
System.exit(-1);
}
Parser parser = new Parser();
final String projectDirectory = args[0];
Map<IPredicate, IRelation> factMap = new HashMap<>();
/**
* The following loop -- given a project directory -- will list and read parse all fact files in
* its "/facts" subdirectory. This allows you to have multiple .iris files with your program
* facts. For instance you can have one file for each relation's facts as our examples show.
*/
final File factsDirectory = new File(projectDirectory + "/facts");
if (factsDirectory.isDirectory()) {
for (final File fileEntry : factsDirectory.listFiles()) {
if (fileEntry.isDirectory())
System.out.println("Omitting directory " + fileEntry.getPath());
else {
Reader factsReader = new FileReader(fileEntry);
parser.parse(factsReader);
// Retrieve the facts and put all of them in factMap
factMap.putAll(parser.getFacts());
}
}
} else {
System.err.println("Invalid facts directory path");
System.exit(-1);
}
File rulesFile = new File(projectDirectory + "/rules.iris");
Reader rulesReader = new FileReader(rulesFile);
File queriesFile = new File(projectDirectory + "/queries.iris");
Reader queriesReader = new FileReader(queriesFile);
// Parse rules file.
parser.parse(rulesReader);
// Retrieve the rules from the parsed file.
List<IRule> rules = parser.getRules();
// Parse queries file.
parser.parse(queriesReader);
// Retrieve the queries from the parsed file.
List<IQuery> queries = parser.getQueries();
// Create a default configuration.
Configuration configuration = new Configuration();
// Enable Magic Sets together with rule filtering.
configuration.programOptmimisers.add(new MagicSets());
// Create the knowledge base.
IKnowledgeBase knowledgeBase = new KnowledgeBase(factMap, rules, configuration);
// Evaluate all queries over the knowledge base.
for (IQuery query : queries) {
List<IVariable> variableBindings = new ArrayList<>();
IRelation relation = knowledgeBase.execute(query, variableBindings);
// Output the variables.
System.out.println("\n" + query.toString() + "\n" + variableBindings);
// Output each tuple in the relation, where the term at position i
// corresponds to the variable at position i in the variable
// bindings list.
for (int i = 0; i < relation.size(); i++) {
System.out.println(relation.get(i));
}
}
}