Package nl.uu.cs.aplib.agents

Class PrologReasoner

java.lang.Object

nl.uu.cs.aplib.agents.PrologReasoner

public class PrologReasoner
extends Object

Provide a Prolog-engine where you can add facts and rules, and perform queries/inference over those facts.

Author:

Wish.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	PrologReasoner.PredicateName	A representation of a predicate-name.
static class	PrologReasoner.QueryResult	Representing the result of a Prolog-query.
static class	PrologReasoner.Rule	A represenration of a Prolog-rule.

Field Summary

Fields

Modifier and Type	Field	Description
alice.tuprolog.Prolog	prolog

Constructor Summary

Constructors

Constructor	Description
PrologReasoner()

Method Summary

Modifier and Type	Method	Description
PrologReasoner	add(PrologReasoner.Rule... rules)	Add new rules to the Prolog engine.
static String	and(String... args)	Construct a string representing the prolog-term "(t1,t2,...)"; it denotes the conjunction of the composing terms.
PrologReasoner	facts(String... facts)	Add new facts to the Prolog engine.
static int	intval(alice.tuprolog.Term t)
void	loadTheory(String filename)	Clear the current theory, and replace it with a theory loaded form the specified file.
static void	main(String[] args)
static String	not(String t)	Construct a string representing the prolog-term "not(t)".
static String	or(String... args)	Construct a string representing the prolog-term "(t1; t2; ...)", which denotes the disjunction of the composing terms.
static PrologReasoner.PredicateName	predicate(String name)	Construct a predicate name, e.g.
PrologReasoner.QueryResult	query(String queryterm)	Pose a query to the prolog-engine.
List<PrologReasoner.QueryResult>	queryAll(String queryterm)
PrologReasoner	removeFacts(String... facts)	Remove facts from the Prolog engine.
static PrologReasoner.Rule	rule(String head)	Construct a representation of a prolog-rule consisting of just the head, and empty body.
void	saveTheory(String filename)	Save the current set of facts and rules to a file, which can be re-loaded later.
String	showTheory()
static String	stringval(alice.tuprolog.Term t)
boolean	test(String queryterm)	Check if the given query would return a result.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

prolog

public alice.tuprolog.Prolog prolog

Constructor Details

PrologReasoner

public PrologReasoner()

Method Details

rule

public static PrologReasoner.Rule rule(String head)

Construct a representation of a prolog-rule consisting of just the head, and empty body. So, it has the form "head :- ".

predicate

public static PrologReasoner.PredicateName predicate(String name)

Construct a predicate name, e.g. "P". This can be combined with arguments to construct a string representing a predicate, e.g. as in: predicate("P").on("X","Y")

not

public static String not(String t)

Construct a string representing the prolog-term "not(t)".

or

public static String or(String... args)

Construct a string representing the prolog-term "(t1; t2; ...)", which denotes the disjunction of the composing terms.

and

public static String and(String... args)

Construct a string representing the prolog-term "(t1,t2,...)"; it denotes the conjunction of the composing terms.

facts

public PrologReasoner facts(String... facts)
                     throws alice.tuprolog.InvalidTheoryException

Add new facts to the Prolog engine.

Throws:

alice.tuprolog.InvalidTheoryException

removeFacts

public PrologReasoner removeFacts(String... facts)
                           throws alice.tuprolog.InvalidTheoryException

Remove facts from the Prolog engine.

Throws:

alice.tuprolog.InvalidTheoryException

add

public PrologReasoner add(PrologReasoner.Rule... rules)
                   throws alice.tuprolog.InvalidTheoryException

Add new rules to the Prolog engine.

Throws:

alice.tuprolog.InvalidTheoryException

query

public PrologReasoner.QueryResult query(String queryterm)

Pose a query to the prolog-engine.

queryAll

public List<PrologReasoner.QueryResult> queryAll(String queryterm)

test

public boolean test(String queryterm)

Check if the given query would return a result. If it does, this method returns true, and else false.

intval

public static int intval(alice.tuprolog.Term t)

stringval

public static String stringval(alice.tuprolog.Term t)

showTheory

public String showTheory()

saveTheory

public void saveTheory(String filename)
                throws IOException

Save the current set of facts and rules to a file, which can be re-loaded later.

Throws:

IOException

loadTheory

public void loadTheory(String filename)
                throws IOException,
alice.tuprolog.InvalidTheoryException

Clear the current theory, and replace it with a theory loaded form the specified file.

Throws:

IOException

alice.tuprolog.InvalidTheoryException

main

public static void main(String[] args)
                 throws alice.tuprolog.InvalidTheoryException,
IOException

Throws:

alice.tuprolog.InvalidTheoryException

IOException