org.deri.iris.evaluation.topdown.oldt
Class MemoTable

java.lang.Object
  java.util.AbstractMap<K,V>
      java.util.HashMap<IAtom,IRelation>
          org.deri.iris.evaluation.topdown.oldt.MemoTable

All Implemented Interfaces:

Serializable, Cloneable, Map<IAtom,IRelation>

public class MemoTable
extends HashMap<IAtom,IRelation>
implements Map<IAtom,IRelation>

Author:

gigi

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from interface java.util.Map

Map.Entry<K,V>

Constructor Summary

MemoTable()
Constructor

Method Summary

IRelation	add(IAtom atom, ITuple tuple) Add a answer (which is an ITuple) to an atom.
void	addAll(IAtom atom, IRelation relationFromSubtree)
boolean	containsKey(IAtom atom)
ITuple	get(IAtom atom, int i) Get the ith answer tuple
IRelation	get(IAtom atom, Map<IVariable,ITerm> variableMap)

Methods inherited from class java.util.HashMap

clear, clone, containsKey, containsValue, entrySet, get, isEmpty, keySet, put, putAll, remove, size, values

Methods inherited from class java.util.AbstractMap

equals, hashCode, toString

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.Map

clear, containsKey, containsValue, entrySet, equals, get, hashCode, isEmpty, keySet, put, putAll, remove, size, values

Constructor Detail

MemoTable

public MemoTable()

Constructor

Method Detail

add

public IRelation add(IAtom atom,
                     ITuple tuple)

Add a answer (which is an ITuple) to an atom. If the relation was not initialized before (there was no answer related to the atom), the empty relation will be returned. Since the OLDT table does not allow null values, null is returned if the atom is null. If the tuple is null, the relation will be initialized with the empty relation or remain unchanged.

Parameters:

atom - the unique, ungrounded atom

tuple - a answer tuple. The arity of the tuple must be equal to the number of distinct variables in the atom.

Returns:

previous answer relation associated with specified atom.

get

public IRelation get(IAtom atom,
                     Map<IVariable,ITerm> variableMap)

get

public ITuple get(IAtom atom,
                  int i)

Get the ith answer tuple

Parameters:

atom - memo atom

i - index position

Returns:

answer tuple from answer relation, at the given index position or null if there was no answer found

containsKey

public boolean containsKey(IAtom atom)

addAll

public void addAll(IAtom atom,
                   IRelation relationFromSubtree)