GroundAtom.java

Go to the documentation of this file.

package edu.tum.cs.logic;

import java.util.Map;
import java.util.Set;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import edu.tum.cs.srl.Database;
import edu.tum.cs.util.StringTool;

public class GroundAtom extends Formula {
        public String predicate;
        public String[] args;
        public int index;

        public GroundAtom(String predicate, String[] args) {
                this.predicate = predicate;
                this.args = args;
                index = -1;
        }

        public GroundAtom(String gndAtom) {
                Pattern p = Pattern.compile("(\\w+)\\(([^\\)]+)\\)");
                Matcher m = p.matcher(gndAtom);
                if(!m.matches()) {
                        throw new RuntimeException("Could not parse ground atom '" + gndAtom + "'");
                }
                predicate = m.group(1);
                args = m.group(2).split("\\s*,\\s*");
                index = -1;
        }

        public boolean isTrue(IPossibleWorld w) {
                return w.isTrue(this);
        }

        public void setIndex(int i) {
                index = i;
        }

        @Override
        public void getVariables(Database db, Map<String, String> ret) {
        }

        @Override
        public Formula ground(Map<String, String> binding, WorldVariables vars, Database db) {
                return this;
        }

        @Override
        public void getGroundAtoms(Set<GroundAtom> ret) {
                ret.add(this);
        }

        @Override
        public String toString() {
                return predicate + "(" + StringTool.join(",", args) + ")";
        }

        @Override
        public Formula toCNF() {
                return this;
        }
        
        @Override
        public Formula toNNF() {                
                return this;
        }

        @Override
        public boolean equals(Object other) {
                int otherIdx = ((GroundAtom)other).index;
                if(this.index == -1 || otherIdx == -1)
                        throw new RuntimeException("Cannot compare GroundAtoms that are not yet part of a WorldVariables collection.");
                return this.index == otherIdx;
        }

        @Override
        public int hashCode() {
                if(this.index == -1)
                        throw new RuntimeException("Tried to compute hash code of GroundAtom that was not yet added to a collection of world variables.");
                return this.index;
        }

    @Override
    public Formula simplify(Database evidence) {
        try {
            // check whether evidence contains this ground atom and return instance of TrueFalse
                if(evidence != null) {
                        String value = evidence.getVariableValue(this.toString(), false);
                    if(value != null) {                  
                        if(value.equals("True"))
                            return TrueFalse.TRUE;
                        else if (value.equals("False"))
                            return TrueFalse.FALSE;
                        else
                                throw new RuntimeException("Database contains invalid boolean value '" + value + "' for atom " + this.toString());
                    }
                }
            // if evidence dosn't contain this atom, there's no change
            return this;
        } 
        catch(Exception e) {
            throw new RuntimeException(e.getMessage());
        }
    }
}

---

srldb
Author(s): Dominik Jain, Stefan Waldherr, Moritz Tenorth
autogenerated on Fri Jan 11 09:58:29 2013