net.sf.tweety.logics.fol.parser

Class FolParser

java.lang.Object

net.sf.tweety.commons.Parser<FolBeliefSet>

net.sf.tweety.logics.fol.parser.FolParser

public class FolParser
extends net.sf.tweety.commons.Parser<FolBeliefSet>

This class implements a parser for first-order logic. The BNF for a first-order knowledge base is given by (starting symbol is KB)

KB ::== SORTSDEC DECLAR FORMULAS
DECLAR ::== (FUNCTORDEC | PREDDEC)*
SORTSDEC ::== ( SORTNAME "=" "{" (CONSTANTNAME ("," CONSTANTNAME)*)? "}" "\n" )*
PREDDEC ::== "type" "(" PREDICATENAME ("(" SORTNAME ("," SORTNAME)* ")")? ")" "\n"
FUNCTORDEC ::== "type" "(" SORTNAME "=" FUNCTORNAME "(" (SORTNAME ("," SORTNAME)*)? ")" ")" "\n"
FORMULAS ::== ( "\n" FORMULA)*
FORMULA ::== ATOM | "forall" VARIABLENAME ":" "(" FORMULA ")" | "exists" VARIABLENAME ":" "(" FORMULA ")" |
"(" FORMULA ")" | FORMULA "&&" FORMULA | FORMULA "||" FORMULA | "!" FORMULA | "+" | "-"
ATOM ::== PREDICATENAME ("(" TERM ("," TERM)* ")")?
TERM ::== VARIABLENAME | CONSTANTNAME | FUNCTORNAME "(" (TERM ("," TERM)*)? ")"

where SORTNAME, PREDICATENAME, CONSTANTNAME, VARIABLENAME, and FUNCTORNAME are sequences of
symbols from {a,...,z,A,...,Z,0,...,9} with a letter at the beginning.

Author:

Matthias Thimm, Anna Gessler

Field Summary

Fields

Modifier and Type	Field and Description
static String	EXISTS_QUANTIFIER exists-quantifier used in syntax
static String	FORALL_QUANTIFIER forall-quantifier used in syntax

Constructor Summary

Constructors

Constructor and Description
FolParser()

Method Summary

Modifier and Type	Method and Description
FolSignature	getSignature() Returns the signature of this parser.
Map<String,net.sf.tweety.logics.commons.syntax.Variable>	getVariables()
FolBeliefSet	parseBeliefBase(Reader reader)
net.sf.tweety.commons.Formula	parseFormula(Reader reader)
void	parseSortDeclaration(String s, FolSignature sig) Parses a sort declaration of the form "SORTNAME "=" "{" (CONSTANTNAME ("," CONSTANTNAME)*)? "}"" and modifies the given signature accordingly.
void	parseTypeDeclaration(String s, FolSignature sig) Parses a predicate declaration of the form "type" "(" PREDICATENAME "(" (SORTNAME ("," SORTNAME)*)? ")" ")" or a functor declaration of the form "type" "(" SORTNAME "=" FUNCTORNAME "(" (SORTNAME ("," SORTNAME)*)? ")" ")" and modifies the given signature accordingly.
void	setSignature(FolSignature signature) Sets the signature for this parser.
void	setVariables(Map<String,net.sf.tweety.logics.commons.syntax.Variable> variables)

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

Field Detail

FORALL_QUANTIFIER

public static final String FORALL_QUANTIFIER

forall-quantifier used in syntax

See Also:

Constant Field Values

EXISTS_QUANTIFIER

public static final String EXISTS_QUANTIFIER

exists-quantifier used in syntax

See Also:

Constant Field Values

Constructor Detail

FolParser

public FolParser()

Method Detail

parseBeliefBase

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

Specified by:

parseBeliefBase in class net.sf.tweety.commons.Parser<FolBeliefSet>

Throws:

IOException

net.sf.tweety.commons.ParserException

parseSortDeclaration

public void parseSortDeclaration(String s,
                                 FolSignature sig)
                          throws net.sf.tweety.commons.ParserException

Parses a sort declaration of the form "SORTNAME "=" "{" (CONSTANTNAME ("," CONSTANTNAME)*)? "}"" and modifies the given signature accordingly.

Parameters:

s - a string

sig - a signature

Throws:

net.sf.tweety.commons.ParserException

parseTypeDeclaration

public void parseTypeDeclaration(String s,
                                 FolSignature sig)
                          throws net.sf.tweety.commons.ParserException

Parses a predicate declaration of the form "type" "(" PREDICATENAME "(" (SORTNAME ("," SORTNAME)*)? ")" ")" or a functor declaration of the form "type" "(" SORTNAME "=" FUNCTORNAME "(" (SORTNAME ("," SORTNAME)*)? ")" ")" and modifies the given signature accordingly.

Parameters:

s - a string

sig - a signature

Throws:

net.sf.tweety.commons.ParserException

parseFormula

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

Specified by:

parseFormula in class net.sf.tweety.commons.Parser<FolBeliefSet>

Throws:

IOException

net.sf.tweety.commons.ParserException

setSignature

public void setSignature(FolSignature signature)

Sets the signature for this parser.

Parameters:

signature - a fol signature.

getSignature

public FolSignature getSignature()

Returns the signature of this parser.

Returns:

the signature of this parser.

getVariables

public Map<String,net.sf.tweety.logics.commons.syntax.Variable> getVariables()

setVariables

public void setVariables(Map<String,net.sf.tweety.logics.commons.syntax.Variable> variables)