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

Class DlParser

  • public class DlParser
extends 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 Detail

      • DlParser

        public DlParser()

    • Method Detail

      • parseBeliefBase

        public DlBeliefSet parseBeliefBase​(java.io.Reader reader)
                            throws java.io.IOException,
                                   ParserException
        Description copied from class: Parser
        Parses the given reader into a belief base of the given type.
        Specified by:
        parseBeliefBase in class Parser<DlBeliefSet,​DlAxiom>
        Parameters:
        reader - a reader
        Returns:
        a belief base
        Throws:
        java.io.IOException - if some IO issue occurred.
        ParserException - some parsing exceptions may be added here.

      • parseFormula

        public DlAxiom parseFormula​(java.io.Reader reader)
                     throws java.io.IOException,
                            ParserException
        Description copied from class: Parser
        Parses the given reader into a formula of the given type.
        Specified by:
        parseFormula in class Parser<DlBeliefSet,​DlAxiom>
        Parameters:
        reader - a reader
        Returns:
        a formula
        Throws:
        java.io.IOException - if some IO issue occurred.
        ParserException - some parsing exceptions may be added here.

      • tokenize

        public void tokenize​(java.util.Stack<java.lang.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.