Package org.tweetyproject.action.query.parser

Class ActionQueryParser

java.lang.Object

org.tweetyproject.commons.Parser<SActionQuerySet,SActionQuery>

org.tweetyproject.action.query.parser.ActionQueryParser

public class ActionQueryParser
extends Parser<SActionQuerySet,SActionQuery>

This class implements a parser for action queries in S. The BNF of such queries is given by: (starting symbol is KB)
KB ::== QUERY1 ("\n" QUERY1)*
QUERY1 ::== QUERY ( "requires" REQUIREMENTS )?
QUERY ::== PROPOSITION | QUERY "&&" QUERY | QUERY "||" QUERY | "!" QUERY | "(" QUERY ")" | "+" | "-"
PROPOSITION ::== HOLDSQUERY | ALWAYSQUERY | NECESSARILYQUERY
HOLDSQUERY ::== "holds" "[" STATEFORMULA "]"
ALWAYSQUERY ::== "always" "[" STATEFORMULA "]"
NECESSARILYQUERY ::== "necessarily" "[" STATEFORMULA "]" "after" ACTIONS
ACTIONS ::== ACTION ( ";" ACTION )*
ACTION ::== "{" ACTIONNAME ("," ACTIONNAME)* "}"
REQUIREMENTS ::== REQUIREMENT ("," REQUIREMENT)*
REQUIREMENT ::== (VARIABLENAME "<>" VARIABLENAME | VARIABLENAME "<>" CONSTANTNAME)*

where STATEFORMULA is an unquantified first-order formula without functors,
and VARIABLENAME, CONSTANTNAME are sequences of symbols
from {a,...,z,A,...,Z,0,...,9} with a letter at the beginning.

Author:

Sebastian Homann, Tim Janus (change constant LogicalSymbols to dynamic)

Constructor Summary

Constructors

Constructor	Description
ActionQueryParser(ActionSignature signature)	Constructs a new `ActionQueryParser` with the specified action signature.

Method Summary

Modifier and Type	Method	Description
SActionQuerySet	parseBeliefBase(Reader reader)	Parses a belief base from the given reader.
SActionQuery	parseFormula(Reader reader)	Parses a single formula from the given reader.

Methods inherited from class org.tweetyproject.commons.Parser

isNumeric, parseBeliefBase, parseBeliefBaseFromFile, parseFormula, parseFormulaFromFile, parseListOfBeliefBases, parseListOfBeliefBases, parseListOfBeliefBasesFromFile, parseListOfBeliefBasesFromFile

Methods inherited from class java.lang.Object

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

Constructor Details

ActionQueryParser

public ActionQueryParser(ActionSignature signature)

Constructs a new `ActionQueryParser` with the specified action signature.

Parameters:

signature - the action signature used for parsing action queries.

Method Details

parseBeliefBase

public SActionQuerySet parseBeliefBase(Reader reader)

Parses a belief base from the given reader. The belief base is expected to contain multiple formulas, separated by newlines, which are parsed into an `SActionQuerySet`.

Specified by:

parseBeliefBase in class Parser<SActionQuerySet,SActionQuery>

Parameters:

reader - the reader from which to parse the belief base.

Returns:

an `SActionQuerySet` representing the parsed belief base.

Throws:

ParserException - if an error occurs during parsing.

parseFormula

public SActionQuery parseFormula(Reader reader)
                          throws IOException,
ParserException

Parses a single formula from the given reader.

Specified by:

parseFormula in class Parser<SActionQuerySet,SActionQuery>

Parameters:

reader - the reader from which to parse the formula.

Returns:

an `SActionQuery` representing the parsed formula.

Throws:

IOException - if an I/O error occurs during parsing.

ParserException - if a parsing error occurs.