ubc.cs.JLog.Terms
Class jConjunctTerm

java.lang.Object
  extended by ubc.cs.JLog.Foundation.jType
      extended by ubc.cs.JLog.Terms.jTerm
          extended by ubc.cs.JLog.Terms.jConjunctTerm
All Implemented Interfaces:
iType, iUnifiable, iConsultable, iName, iTerm, iValue
Direct Known Subclasses:
jCons, jIf, jOr

public abstract class jConjunctTerm
extends jTerm


Field Summary
protected  jTerm lhs
           
protected  jTerm rhs
           
 
Fields inherited from class ubc.cs.JLog.Foundation.jType
type
 
Fields inherited from interface ubc.cs.JLog.Terms.iTerm
EQUAL, GREATER_THAN, LESS_THAN
 
Fields inherited from interface ubc.cs.JLog.Foundation.iType
TYPE_ARITHMETIC, TYPE_ATOM, TYPE_BUILTINPREDICATE, TYPE_COMMAND, TYPE_COMPARE, TYPE_COMPOUND, TYPE_CONS, TYPE_IF, TYPE_INTEGER, TYPE_LIST, TYPE_NULLLIST, TYPE_NUMERICCOMPARE, TYPE_OBJECT, TYPE_OPERATOR, TYPE_OR, TYPE_ORPREDICATE, TYPE_PREDICATE, TYPE_PREDICATETERMS, TYPE_REAL, TYPE_TYPE, TYPE_UNARYARITHMETIC, TYPE_UNARYOPERATOR, TYPE_UNDEFINED, TYPE_VARIABLE
 
Constructor Summary
protected jConjunctTerm(jTerm l, jTerm r)
           
 
Method Summary
protected  int compare(jTerm term, boolean first_call, boolean var_equal)
          The private member function for term comparision.
 void consult(jKnowledgeBase kb)
          Consult the given jKnowledgeBase and cache any invariant values (those which would not change until the next time the jKnowledgeBase changes).
 void consultReset()
          Called when the jKnowledgeBase changes.
 jTerm copy(jVariableRegistry vars)
          Internal member function which creates a copy of this term.
protected abstract  jConjunctTerm duplicate(jTerm l, jTerm r)
           
 jTerm duplicate(jVariable[] vars)
          Creates a complete and entirely independant duplicate of this term.
 void enumerateVariables(jVariableVector v, boolean all)
          Adds variables belonging to this term (or belonging to any sub-part of this term) to the jVariableVector
 boolean equivalence(jTerm term, jEquivalenceMapping v)
          The public interface for evaluating term equivalence (i.e., structural similarity).
 jTerm getLHS()
           
 jTerm getRHS()
           
 void registerUnboundVariables(jUnifiedVector v)
          Adds any unbound variables belonging to this term (or belonging to any sub-part of this term) to the jUnifiedVector
 void registerVariables(jVariableVector v)
          Adds all variables belonging to this term (or belonging to any sub-part of this term) to the jUnifiedVector Should be called during the consultation phase by rules for their owned terms both head and base.
 boolean requiresCompleteVariableState()
          Call to determine if enclosing rule should record all variable states.
 void setLHS(jTerm l)
           
 void setRHS(jTerm r)
           
 boolean unify(jTerm term, jUnifiedVector v)
          Determines if this instance and term unify.
 
Methods inherited from class ubc.cs.JLog.Terms.jTerm
compare, copy, getName, getTerm, getValue, isConsultNeeded, toString, toString
 
Methods inherited from class ubc.cs.JLog.Foundation.jType
getType, objectToString
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Field Detail

lhs

protected jTerm lhs

rhs

protected jTerm rhs
Constructor Detail

jConjunctTerm

protected jConjunctTerm(jTerm l,
                        jTerm r)
Method Detail

getLHS

public jTerm getLHS()

getRHS

public jTerm getRHS()

setLHS

public void setLHS(jTerm l)

setRHS

public void setRHS(jTerm r)

compare

protected int compare(jTerm term,
                      boolean first_call,
                      boolean var_equal)
Description copied from class: jTerm
The private member function for term comparision. Compares this instance to the provided jTerm. sub-classes must override.

Specified by:
compare in class jTerm
Parameters:
term - the jTerm to compare with this instance of jTerm. if term is an unknown type then, if first_call is true, call term.compare(this,false) and return the negative result, otherwise return EQUAL.
first_call - true if just invoked by public compare member function. false otherwise.
var_equal - if var_equal is true, then unbound variables are considered equal. var_equal = false is standard prolog behavior.
Returns:
LESS_THAN if this instance is less than term, EQUAL if the two terms are equal, and GREATER_THAN if this instance is greater than term.

requiresCompleteVariableState

public boolean requiresCompleteVariableState()
Description copied from class: jTerm
Call to determine if enclosing rule should record all variable states. A rules goal only tracks variables which were unified, and relies on stack unwinding to unbind all variables. Terms such as cut, which jump back to the containing rules goal require that all variables are restored.

Specified by:
requiresCompleteVariableState in interface iTerm
Overrides:
requiresCompleteVariableState in class jTerm
Returns:
true if all variable bindings must be recorded by the rule containing this term. false otherwise. Normally returns false

registerUnboundVariables

public void registerUnboundVariables(jUnifiedVector v)
Description copied from class: jTerm
Adds any unbound variables belonging to this term (or belonging to any sub-part of this term) to the jUnifiedVector

Specified by:
registerUnboundVariables in interface iTerm
Overrides:
registerUnboundVariables in class jTerm
Parameters:
v - The jUnifiedVector where unbound variables are added to. This parameter is used to as output to the caller, not as input.

equivalence

public boolean equivalence(jTerm term,
                           jEquivalenceMapping v)
Description copied from interface: iTerm
The public interface for evaluating term equivalence (i.e., structural similarity).

Specified by:
equivalence in interface iTerm
Specified by:
equivalence in class jTerm
Parameters:
term - the jTerm to compare with this instance of jTerm.
v - v is the collection of equivalent variable pairs found. It should be empty when first calling this function.
Returns:
true if this instance is equivalent to term, false otherwise.

unify

public boolean unify(jTerm term,
                     jUnifiedVector v)
Description copied from interface: iUnifiable
Determines if this instance and term unify. Every variable which was previously unbound, but which becomes bound during the unification must register itself with the jUnifiedVector. It is the callers responsibility to deal with the unified vector.

Specified by:
unify in interface iUnifiable
Specified by:
unify in interface iTerm
Specified by:
unify in class jTerm
Parameters:
term - the term to unify with this instance.
v - the vector of variables bound during unification. Even if unification fails, this vector may contain recently bound vectors. This parameter is used to as output to the caller, not as input for unify.
Returns:
true if unification succeeded, false otherwise.

registerVariables

public void registerVariables(jVariableVector v)
Description copied from class: jTerm
Adds all variables belonging to this term (or belonging to any sub-part of this term) to the jUnifiedVector Should be called during the consultation phase by rules for their owned terms both head and base. all variables encountered should be unbound. After call, this term should not be modified in any way.

Specified by:
registerVariables in interface iTerm
Specified by:
registerVariables in class jTerm
Parameters:
v - The jUnifiedVector where variables are added to. This parameter is used to as output to the caller, not as input.

enumerateVariables

public void enumerateVariables(jVariableVector v,
                               boolean all)
Description copied from class: jTerm
Adds variables belonging to this term (or belonging to any sub-part of this term) to the jVariableVector

Specified by:
enumerateVariables in interface iTerm
Specified by:
enumerateVariables in class jTerm
Parameters:
v - The jVariabeVector where variables are added to. This parameter is used to as output to the caller, not as input.
all - If true, then all variables should register, otherwise only add non-existentially qualified variables.

duplicate

public jTerm duplicate(jVariable[] vars)
Description copied from class: jTerm
Creates a complete and entirely independant duplicate of this term. User should call only for terms for which registerVariables has already been invoked. Within duplicate, any other calls to duplicate should pass along the same vars array produced by registerVariables since the same duplication path previously taken by registerVariables should be taken by duplicate. This call is designed only for terms which belong to rules and are templates for instantiation. Any variables in the term should be unbound. As implied by the modification restrictions on registerVariables, terms and their children cannot change (especially during call!)

Specified by:
duplicate in interface iTerm
Specified by:
duplicate in class jTerm
Parameters:
vars - The user passes in a duplicate of the variable vector produced from the previous call to registerVariables. vars is produced from the jVariableVector by creating a single duplicate variable for each variable. Since this is created in the same order as the registerVariables, it is now efficient for jVariables to return their unique duplicate.
Returns:
jTerm which is an instantiated duplicate of this term.

copy

public jTerm copy(jVariableRegistry vars)
Description copied from class: jTerm
Internal member function which creates a copy of this term. This member function is designed to duplicate a term, but without the restrictions of the duplicate function. Should only be invoked by copy() or other copy(vars). Should only invoke other copy(vars) functions. Bound variables should return a copy of the bound term.

Specified by:
copy in interface iTerm
Specified by:
copy in class jTerm
Parameters:
vars - The registry of variables and their duplicates. Initially this is empty. As variables generate copies, they add themselves and their copy to the jVariableRegistry, and this is output from the function call. Any further calls with the same vars ensures that the same variable (in a different term) returns the same copy.
Returns:
jTerm which is an instantiated copy of this term.

duplicate

protected abstract jConjunctTerm duplicate(jTerm l,
                                           jTerm r)

consult

public void consult(jKnowledgeBase kb)
Description copied from interface: iConsultable
Consult the given jKnowledgeBase and cache any invariant values (those which would not change until the next time the jKnowledgeBase changes). Where possible, consultable objects should minimize computation and assume that any cached values are still accurate.

Specified by:
consult in interface iConsultable
Specified by:
consult in interface iTerm
Overrides:
consult in class jTerm
Parameters:
kb - the knowledge base which attempted proofs are based upon.

consultReset

public void consultReset()
Description copied from interface: iConsultable
Called when the jKnowledgeBase changes. Should set all cached values to dirty so that a following call to consult would perform a full lookup as required.

Specified by:
consultReset in interface iConsultable
Specified by:
consultReset in interface iTerm
Overrides:
consultReset in class jTerm