|
|||||||||
PREV CLASS NEXT CLASS | FRAMES NO FRAMES | ||||||||
SUMMARY: NESTED | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD |
java.lang.Objectubc.cs.JLog.Foundation.jType
ubc.cs.JLog.Terms.jTerm
public abstract class jTerm
This is the abstract base class for Prolog terms.
Field Summary |
---|
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 | |
---|---|
jTerm()
|
Method Summary | |
---|---|
int |
compare(jTerm term,
boolean var_equal)
The public interface for term comparision, it calls the protected compare that sub-classes must override. |
protected abstract 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()
Public member function which creates a copy of this term. |
abstract jTerm |
copy(jVariableRegistry vars)
Internal member function which creates a copy of this term. |
abstract jTerm |
duplicate(jVariable[] vars)
Creates a complete and entirely independant duplicate of this term. |
abstract void |
enumerateVariables(jVariableVector v,
boolean all)
Adds variables belonging to this term (or belonging to any sub-part of this term) to the jVariableVector |
abstract boolean |
equivalence(jTerm term,
jEquivalenceMapping v)
The public interface for evaluating term equivalence (i.e., structural similarity). |
java.lang.String |
getName()
Returns the name of this instance. |
jTerm |
getTerm()
Returns the non-evaluated jTerm representation of this term. |
jTerm |
getValue()
Return the value of this object after. |
boolean |
isConsultNeeded()
Determine if cached values already exist and hence if consulting is required. |
void |
registerUnboundVariables(jUnifiedVector v)
Adds any unbound variables belonging to this term (or belonging to any sub-part of this term) to the jUnifiedVector |
abstract 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. |
java.lang.String |
toString()
|
abstract java.lang.String |
toString(boolean usename)
Produces a string identifying this term, suitable for display to the console. |
abstract boolean |
unify(jTerm term,
jUnifiedVector v)
Determines if this instance and term unify. |
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 |
Constructor Detail |
---|
public jTerm()
Method Detail |
---|
public jTerm getValue()
iValue
getValue
in interface iTerm
getValue
in interface iValue
jTerm
which represents the evaluated value of this
instance, or the value bound to this instance, in the case of a
variable.public jTerm getTerm()
jTerm
representation of this term.
Variables return the non-evaluated terms they are bound to.
getTerm
in interface iTerm
jTerm
of the non-evaluated term bound to this
instance.public java.lang.String getName()
iName
getName
in interface iName
getName
in interface iTerm
String
containing name of this instance.public int compare(jTerm term, boolean var_equal)
compare
that sub-classes must override.
compare
in interface iTerm
term
- the jTerm
to compare with this instance of
jTerm
.var_equal
- if var_equal
is true
, then unbound
variables are considered equal.
var_equal
= false
is standard prolog
behavior.
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
.protected abstract int compare(jTerm term, boolean first_call, boolean var_equal)
jTerm
. sub-classes must override.
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.
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
.public boolean requiresCompleteVariableState()
cut
, which jump back to the
containing rules goal require that all variables are restored.
requiresCompleteVariableState
in interface iTerm
true
if all variable bindings must be recorded by
the rule containing this term. false
otherwise.
Normally returns false
public void registerUnboundVariables(jUnifiedVector v)
jUnifiedVector
registerUnboundVariables
in interface iTerm
v
- The jUnifiedVector
where unbound variables are
added to. This parameter is used to as output to the caller, not as input.public abstract void registerVariables(jVariableVector v)
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.
registerVariables
in interface iTerm
v
- The jUnifiedVector
where variables are
added to. This parameter is used to as output to the
caller, not as input.public abstract void enumerateVariables(jVariableVector v, boolean all)
jVariableVector
enumerateVariables
in interface iTerm
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.public abstract boolean equivalence(jTerm term, jEquivalenceMapping v)
iTerm
equivalence
in interface iTerm
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.
true
if this instance is equivalent to term
,
false
otherwise.public abstract boolean unify(jTerm term, jUnifiedVector v)
iUnifiable
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.
unify
in interface iUnifiable
unify
in interface iTerm
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
.
true
if unification succeeded,
false
otherwise.public abstract jTerm duplicate(jVariable[] vars)
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!)
duplicate
in interface iTerm
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.
jTerm
which is an instantiated duplicate of this
term.public jTerm copy()
duplicate
function.
Sub-classes need not override, only implement the abstract
copy(vars)
member function. copy is not as efficient as
duplicate
.
copy
in interface iTerm
jTerm
which is an instantiated copy of this
term.public abstract jTerm copy(jVariableRegistry vars)
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.
copy
in interface iTerm
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.
jTerm
which is an instantiated copy of this
term.public void consult(jKnowledgeBase kb)
iConsultable
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.
consult
in interface iConsultable
consult
in interface iTerm
kb
- the knowledge base which attempted proofs are based upon.public void consultReset()
iConsultable
jKnowledgeBase
changes. Should set all cached values to
dirty so that a following call to consult
would perform a full lookup
as required.
consultReset
in interface iConsultable
consultReset
in interface iTerm
public boolean isConsultNeeded()
iConsultable
isConsultNeeded
in interface iConsultable
isConsultNeeded
in interface iTerm
false
if cached values are valid,
true
otherwise, if consult
should be
called.public abstract java.lang.String toString(boolean usename)
false
is the default for displaying the term,
true
for displaying this term in a user query.
toString
in interface iTerm
String
which is a textual representation of this
term.public java.lang.String toString()
toString
in class java.lang.Object
|
|||||||||
PREV CLASS NEXT CLASS | FRAMES NO FRAMES | ||||||||
SUMMARY: NESTED | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD |