com.ibm.able.rules
Class AbleSelector

java.lang.Object
  com.ibm.able.rules.AbleSelector

All Implemented Interfaces:

java.io.Serializable

public class AbleSelector

extends java.lang.Object

implements java.io.Serializable

This class represents a single AbleVariable (the selected variable) and a set of constraints on the value that variable can take.

Selectors are created as part of when/do pattern match rules and directly via use of Selector data types in the Able Rule Language.

See Also:

Serialized Form

Field Summary

protected AbleExpression	constraintExpr
protected java.util.Vector	constraints
protected AbleRuleSet	myRuleSet
protected boolean	positive
protected AbleVariable	selectorVariable

Constructor Summary

AbleSelector()
Create an AbleSelector object

AbleSelector(AbleRuleSet theRuleSet, AbleVariable selector, java.util.Vector constraints, boolean positive)
Construct a selector object

AbleSelector(AbleRuleSet theRuleSet, java.lang.String theVariableName, AbleExpression theConstraintExpression)
Construct a selector object from the specified variable name and expression.

AbleSelector(AbleVariable selector, AbleExpression constraintExpr, boolean positive)
Construct a selector object.

AbleSelector(AbleVariable selector, java.lang.Object constraintExpr, boolean positive)
Construct a selector object.

AbleSelector(AbleVariable selector, java.util.Vector constraints)
Create an AbleSelector object

Method Summary

void	addConstraint(java.lang.Object constraint) Add a Clause or Predicate constraint to this selector
java.lang.Object	any(AbleOclCollection theCollection) From the specified collection, find and return the first element that satisfies the contained expression.
java.lang.String	arlString() Return a formal ARL string that describes this clause.
java.lang.String	armlString() Return a formal XML string that describes this clause.
AbleOclCollection	collect(AbleOclCollection theCollection) Collect the values returned when the expression is evaluated against each element of the specified collection.
void	convertExpressionToClauses(AbleRuleSet theRuleSet) Convert the constraintExpression to a Vector of AbleAntecedentClauses
boolean	exists(AbleOclCollection theCollection) Determine whether the collection contains at least one element for which the expression evaluates to true.
boolean	forAll(AbleOclCollection theCollection) Determine whether all elements of the collection are true for the contained expression expression.
AbleExpression	getConstraintExpression() Retrieve the constraint expression
java.util.Vector	getConstraints() Retrieve the list of constraints (antecedent clauses)
java.lang.Object	getSelectorValue() Return the value of the selector variable
AbleVariable	getSelectorVariable() Return the selector variable
java.lang.String	getTemplateString(java.util.Vector theTemplateVars) Retrieve a text format string for use by rule templates.
boolean	isNegative() Check if selector is negative (checking for patterns that don't exist)
boolean	isPositive() Check if selector is positive (looking for matches)
boolean	isUnique(AbleOclCollection theCollection) Determine whether the expression evaluates to a unique value for each element of the specified collection.
java.util.Vector	match(AbleWorkingMemory workingMemory) Find a list of matching instances in working memory
boolean	one(AbleOclCollection theCollection) From the specified collection, find and return the first element that satisfies the contained expression.
AbleOclCollection	reject(AbleOclCollection theCollection) From the specified collection, create a list of those elements that evaluate to false against the contained expression.
AbleOclCollection	select(AbleOclCollection theCollection) From the specified collection, create a list of those elements that evaluate to true against the contained expression.
java.lang.String	traceString(int theTraceStringFlavor) Retrieve a string describing (the contents of) the object.
java.lang.String	xmlString() Return a formal XML string that describes this clause.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

constraints

protected java.util.Vector constraints

selectorVariable

protected AbleVariable selectorVariable

positive

protected boolean positive

constraintExpr

protected AbleExpression constraintExpr

myRuleSet

protected AbleRuleSet myRuleSet

Constructor Detail

AbleSelector

public AbleSelector()

Create an AbleSelector object

AbleSelector

public AbleSelector(AbleVariable selector,
                    java.util.Vector constraints)

Create an AbleSelector object

Parameters:

selector - The selector variable

constraints - A vector of constraints on the values bound to the selector variable The constraints are AbleAntecedentClause objects

AbleSelector

public AbleSelector(AbleRuleSet theRuleSet,
                    AbleVariable selector,
                    java.util.Vector constraints,
                    boolean positive)

Construct a selector object

Parameters:

theRuleSet - The ruleset object this selector belongs to

selector - The selector variable

constraints - A vector of constraints on the values bound to the selector variable The constraints are AbleAntecedentClause objects

positive - A boolean , true if the selector is positive, false if negative

AbleSelector

public AbleSelector(AbleVariable selector,
                    AbleExpression constraintExpr,
                    boolean positive)

Construct a selector object.

Parameters:

selector - The selector variable

constraintExpr - A constraint expression bound to the selector variable.

positive - A boolean , true if the selector is positive, false if negative

AbleSelector

public AbleSelector(AbleVariable selector,
                    java.lang.Object constraintExpr,
                    boolean positive)
             throws AbleParException

Construct a selector object.

Parameters:

selector - The selector variable.

constraintExpr - An AbleExpression bound to the selector variable. The constraints are AbleAntecedentClause objects.

positive - A boolean, true if the selector is positive, false if negative.

AbleSelector

public AbleSelector(AbleRuleSet theRuleSet,
                    java.lang.String theVariableName,
                    AbleExpression theConstraintExpression)

Construct a selector object from the specified variable name and expression.

Parameters:

theRuleSet - The ruleset in which this selector is evaluated.

theVariableName - The name of the selector variable; it must identify a variable declared within the specified ruleset.

theConstraintExpression - An expression that, when evaluated with an instance of the specified variable, must return a boolean value.

Method Detail

addConstraint

public void addConstraint(java.lang.Object constraint)

Add a Clause or Predicate constraint to this selector

Parameters:

constraint - An AntecedentClause that places a constraint on instances bound to the selector

isPositive

public boolean isPositive()

Check if selector is positive (looking for matches)

Returns:

true if the selector is checking for matches

isNegative

public boolean isNegative()

Check if selector is negative (checking for patterns that don't exist)

Returns:

true if the selector is checking for no matches

match

public java.util.Vector match(AbleWorkingMemory workingMemory)
                       throws AbleDataException

Find a list of matching instances in working memory

Parameters:

workingMemory - The associated working memory to be searched

Throws:

AbleDataException

exists

public boolean exists(AbleOclCollection theCollection)
               throws AbleDataException

Determine whether the collection contains at least one element for which the expression evaluates to true.

Parameters:

theCollection - The collection of elements to examine.

Returns:

true if the expression evaluates to true for at least one element of the collection; otherwise returns false.

Throws:

AbleDataException

forAll

public boolean forAll(AbleOclCollection theCollection)
               throws AbleDataException

Determine whether all elements of the collection are true for the contained expression expression.

Parameters:

theCollection - The collection of elements to examine.

Returns:

true if the expression evaluates to true for all elements of the collection; otherwise false is returned.

Throws:

AbleDataException

isUnique

public boolean isUnique(AbleOclCollection theCollection)
                 throws AbleDataException

Determine whether the expression evaluates to a unique value for each element of the specified collection.

Parameters:

theCollection - The collection of elements to examine.

Returns:

true if the expression evaluates to a unique value for each element of the collection; otherwise false is returned.

Throws:

AbleDataException

any

public java.lang.Object any(AbleOclCollection theCollection)
                     throws AbleDataException

From the specified collection, find and return the first element that satisfies the contained expression.

Parameters:

theCollection - The collection of elements to examine.

Returns:

The first element of the collection to satisfy expression, or null if no element satisfies the expression.

Throws:

AbleDataException

one

public boolean one(AbleOclCollection theCollection)
            throws AbleDataException

From the specified collection, find and return the first element that satisfies the contained expression.

Parameters:

theCollection - The collection of elements to examine.

Returns:

true if just one element satisfies the expression; otherwise false is returned.

Throws:

AbleDataException

collect

public AbleOclCollection collect(AbleOclCollection theCollection)
                          throws AbleDataException

Collect the values returned when the expression is evaluated against each element of the specified collection.

Parameters:

theCollection - The collection of elements to examine.

Returns:

a collection of values returned by evaluating the expression against each element of the specified collection.

Throws:

AbleDataException

select

public AbleOclCollection select(AbleOclCollection theCollection)
                         throws AbleDataException

From the specified collection, create a list of those elements that evaluate to true against the contained expression.

Parameters:

theCollection - The collection of elements to examine.

Returns:

A subcollection of elements from the specified collection. The collection may be empty, but it will not be null.

Throws:

AbleDataException

reject

public AbleOclCollection reject(AbleOclCollection theCollection)
                         throws AbleDataException

From the specified collection, create a list of those elements that evaluate to false against the contained expression.

Parameters:

theCollection - The collection of elements to examine.

Returns:

A subcollection of elements from the specified collection. The collection may be empty, but it will not be null.

Throws:

AbleDataException

getSelectorVariable

public AbleVariable getSelectorVariable()

Return the selector variable

getSelectorValue

public java.lang.Object getSelectorValue()
                                  throws AbleDataException

Return the value of the selector variable

Throws:

AbleDataException

getConstraints

public java.util.Vector getConstraints()

Retrieve the list of constraints (antecedent clauses)

getConstraintExpression

public AbleExpression getConstraintExpression()

Retrieve the constraint expression

convertExpressionToClauses

public void convertExpressionToClauses(AbleRuleSet theRuleSet)

Convert the constraintExpression to a Vector of AbleAntecedentClauses

Parameters:

theRuleSet - An AbleRuleSet objet

arlString

public java.lang.String arlString()

Return a formal ARL string that describes this clause.

For antecedent clauses, add the weight of the clause, but only if the weight is something other than the default weight.

Returns:

A String that describes this clause in formal rule language.

xmlString

public java.lang.String xmlString()

Return a formal XML string that describes this clause.

For antecedent clauses, add the weight of the clause, but only if the weight is something other than the default weight.

Returns:

A String that describes this clause in XML.

armlString

public java.lang.String armlString()

Return a formal XML string that describes this clause.

For antecedent clauses, add the weight of the clause, but only if the weight is something other than the default weight.

Returns:

A String that describes this clause in XML.

getTemplateString

public java.lang.String getTemplateString(java.util.Vector theTemplateVars)
                                   throws AbleDataException

Retrieve a text format string for use by rule templates. The string contains "{n}" strings, where the index 'n' corresponds to the template variables defined in the rule template. This string is based on the standard arlString() representation of the rule. After replacement of the template variable values, the resulting string must be a valid ARL format string that can be parsed.

Parameters:

theTemplateVars - An ordered list of template variables referenced by this selector.

Returns:

A Text format string used to create a new rule instance.

Throws:

AbleDataException

See Also:

AbleRuleTemplate

traceString

public java.lang.String traceString(int theTraceStringFlavor)

Retrieve a string describing (the contents of) the object.

Parameters:

theTraceStringFlavor - An Able.TraceStringFlavor value.

Returns:

A String containing the current contents of the object.