Atom.java

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package edu.tum.cs.logic;

import java.util.Collection;
import java.util.Map;

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

public class Atom extends UngroundedFormula {

        public Collection<String> params;
        public String predName;

        public Atom(String predName, Collection<String> params) {
                this.predName = predName;
                this.params = params;
        }

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

        @Override
        public void getVariables(Database db, Map<String, String> ret) throws Exception {
        Signature sig = db.getSignature(predName);
        if(sig == null)
                throw new Exception("Unknown predicate '" + predName + "'");
                int i = 0;
                for(String param : params) {
                        if(isVariable(param)) {
                                String type;
                                if(i < sig.argTypes.length)
                                        type = sig.argTypes[i];
                                else
                                        type = sig.returnType;
                                String oldval = ret.put(param, type);
                                if(oldval != null && !type.equals(oldval))
                                        throw new Exception("The variable " + param + " is bound to more than one domain: " + oldval + " and " + type);
                        }
                        ++i;
                }
        }

        public static boolean isVariable(String paramName) {
                return Character.isLowerCase(paramName.charAt(0));
        }

        @Override
        public Formula ground(Map<String, String> binding, WorldVariables vars, Database db) throws Exception {
                StringBuffer sb = new StringBuffer(predName + "(");
                int i = 0;
                for(String param : params) {
                        if(i++ > 0)
                                sb.append(',');
                        String value = binding.get(param);
                        if(value == null) { // if the binding contains no value for a parameter, it must be a constant
                                if(isVariable(param))
                                        throw new Exception("Cannot ground " + toString() + " with binding "  + binding + " - variable " + param + " unbound.");
                                value = param;
                        }
                        sb.append(value);
                }
                sb.append(')');
                String strGA = sb.toString();
                GroundAtom ga = vars.get(strGA);
                if(ga == null)
                        throw new Exception("Could not find ground atom '" + strGA + "' in set of world variables " + vars);
                return ga;
        }

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

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