Package net.sf.tweety.logics.dl.parser

Class DlParser

java.lang.Object

net.sf.tweety.commons.Parser<DlBeliefSet,DlAxiom>

net.sf.tweety.logics.dl.parser.DlParser

public class DlParser
extends net.sf.tweety.commons.Parser<DlBeliefSet,DlAxiom>

This class implements a parser for the description logic ALC (attributive concept language with complements). The input syntax is based on the input syntax of the Racer reasoner.
Note: Racer is built for the description logic SRIQ(D) (= the DL that corresponds to the OWL2 language), which is more expressive than ALC. SRIQ(D)-exclusive elements like inverse roles, role hierarchies and at-least restrictions are not supported by this parser. Furthermore, the syntax of universal and existential restrictions is different for reasons of simplification (see BNF).

The input syntax for an ALC knowledge base is given by the following BNF (starting symbol is KB):
KB ::== SIGNATURE FORMULAS
SIGNATURE ::== "signature(" (CONCEPT_DECLAR)? (ROLE_DECLAR)? (INDIVIDUAL_DECLAR)? ")"
CONCEPT_DECLAR ::== ("\n")* "atomic-concepts(" (CONCEPTNAME)* ")"
ROLE_DECLAR ::== ("\n")* "roles(" (ROLENAME)* ")"
INDIVIDUAL_DECLAR ::== ("\n")* "individuals(" (CONSTANTNAME)* ")"
AXIOMS ::== ("\n" AXIOM)*
AXIOM ::== "instance " " " CONSTANTNAME " " CONCEPT | "related " CONSTANTNAME " " CONSTANTNAME " " ROLENAME |
"implies " " " CONCEPT " " CONCEPT | "equivalent" CONCEPT " " CONCEPT
CONCEPT ::== "(" CONCEPT ")" | CONCEPTNAME | "not " CONCEPT | "*top*" | "*bottom*" | "top" | "bottom" |
"and " CONCEPT " " CONCEPT | "or " CONCEPT " " CONCEPT |
"forall " ROLENAME " " CONCEPT | "exists " ROLENAME " " CONCEPT

where CONCEPTNAME, ROLENAME, CONSTANTNAME are sequences of
symbols from {a,...,z,A,...,Z,0,...,9} with a letter at the beginning
excluding {"top","bottom"}.

Author:

Anna Gessler, Matthias Thimm

Constructor Summary

Constructors

Constructor	Description
DlParser()

Method Summary

Modifier and Type	Method	Description
DlSignature	getSignature()	Returns the signature of this parser.
DlBeliefSet	parseBeliefBase(Reader reader)
DlAxiom	parseFormula(Reader reader)
void	setSignature(DlSignature signature)	Sets the signature for this parser.
void	tokenize(Stack<Object> stack, int c)	This method reads one character from the given reader and appropriately tokenizes it.

Methods inherited from class net.sf.tweety.commons.Parser

isNumeric, parseBeliefBase, parseBeliefBaseFromFile, parseFormula, parseFormulaFromFile

Methods inherited from class java.lang.Object

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

Constructor Detail

DlParser

public DlParser()

Method Detail

parseBeliefBase

public DlBeliefSet parseBeliefBase(Reader reader)
                            throws IOException,
                                   net.sf.tweety.commons.ParserException

Specified by:

parseBeliefBase in class net.sf.tweety.commons.Parser<DlBeliefSet,DlAxiom>

Throws:

IOException

net.sf.tweety.commons.ParserException

parseFormula

public DlAxiom parseFormula(Reader reader)
                     throws IOException,
                            net.sf.tweety.commons.ParserException

Specified by:

parseFormula in class net.sf.tweety.commons.Parser<DlBeliefSet,DlAxiom>

Throws:

IOException

net.sf.tweety.commons.ParserException

tokenize

public void tokenize(Stack<Object> stack,
                     int c)

This method reads one character from the given reader and appropriately tokenizes it.

Parameters:

stack - used for monitoring the read items

c - token from stream

setSignature

public void setSignature(DlSignature signature)

Sets the signature for this parser.

Parameters:

signature - a DL signature.

getSignature

public DlSignature getSignature()

Returns the signature of this parser.

Returns:

the signature of this parser.