org.qtitools.qti.node.expression.operator
Class Match

java.lang.Object
  org.qtitools.qti.node.AbstractNode
      org.qtitools.qti.node.AbstractObject
          org.qtitools.qti.node.expression.AbstractExpression
              org.qtitools.qti.node.expression.operator.Match

All Implemented Interfaces:

java.io.Serializable, Expression, ExpressionParent, XmlNode, XmlObject, Validatable

public class Match
extends AbstractExpression

The match operator takes two sub-expressions which must both have the same base-type and cardinality. The result is A single boolean with A value of true if the two expressions represent the same value and false if they do not. If either sub-expression is NULL then the operator results in NULL.

The match operator must not be confused with broader notions of equality such as numerical equality. To avoid confusion, the match operator should not be used to compare subexpressions with base-types of float and must not be used on sub-expressions with A base-type of duration.

Author:

Jiri Kajaba

See Also:

Cardinality, BaseType, Serialized Form

Field Summary

static java.lang.String

CLASS_TAG Name of this class in xml schema.

Fields inherited from class org.qtitools.qti.node.expression.AbstractExpression

logger

Fields inherited from interface org.qtitools.qti.node.expression.Expression

DISPLAY_NAME

Fields inherited from interface org.qtitools.qti.node.XmlNode

INDENT, NEW_LINE, SIMPLE_NAME_INNER_SEPARATOR, SIMPLE_NAMES_SEPARATOR

Constructor Summary

Match(ExpressionParent parent)
Constructs expression.

Method Summary

protected Value	evaluateSelf(int depth) Evaluates this expression.
java.lang.String	getClassTag() Gets QTI class name of this node.
BaseType[]	getRequiredBaseTypes(int index) Gets list of all acceptable baseTypes which can child expression at given position produce.
Cardinality[]	getRequiredCardinalities(int index) Gets list of all acceptable cardinalities which can child expression at given position produce.
protected ValidationResult	validateChildren() Validates children (body) of this node.

Methods inherited from class org.qtitools.qti.node.expression.AbstractExpression

evaluate, getBaseType, getCardinality, getChildren, getFirstChild, getParent, getParentRequiredBaseTypes, getParentRequiredCardinalities, getProducedBaseTypes, getProducedCardinalities, getProducedNumericalBaseTypes, getRequiredSameBaseTypes, getRequiredSameCardinalities, getSecondChild, getType, getValue, isAnyChildNull, isNull, isVariable, reset, toString, validate

Methods inherited from class org.qtitools.qti.node.AbstractObject

getParentItem, getParentResult, getParentTest, setParent

Methods inherited from class org.qtitools.qti.node.AbstractNode

attrToXmlString, bodyToXmlString, getAttributes, getFullName, getIndent, getNode, getNode, getNode, getNodeGroups, getParentRoot, getSimpleName, getSourceFile, getSourceNode, getSourceString, getSourceUrl, hasChildNodes, load, load, load, load, loadAttributes, readChild, readChildren, setParent, setSourceFile, setSourceNode, setSourceString, setSourceUrl, toXmlString, toXmlString, validateAttributes

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.qtitools.qti.node.XmlObject

getParentItem, getParentResult, getParentTest, setParent

Methods inherited from interface org.qtitools.qti.node.XmlNode

getAttributes, getFullName, getNodeGroups, getParentRoot, getSimpleName, getSourceFile, getSourceNode, getSourceString, getSourceUrl, hasChildNodes, load, load, load, load, setSourceFile, setSourceNode, setSourceString, setSourceUrl, toXmlString, toXmlString

Field Detail

CLASS_TAG

public static final java.lang.String CLASS_TAG

Name of this class in xml schema.

See Also:

Constant Field Values

Constructor Detail

Match

public Match(ExpressionParent parent)

Constructs expression.

Parameters:

parent - parent of this expression

Method Detail

getClassTag

public java.lang.String getClassTag()

Description copied from interface: XmlNode

Gets QTI class name of this node.

QTI class name has very important role during loading/saving nodes.

For example: Java class name is AssessmentTest; QTI class name is assessmentTest.

Specified by:

getClassTag in interface XmlNode

Specified by:

getClassTag in class AbstractNode

Returns:

QTI class name of this node

getRequiredCardinalities

public Cardinality[] getRequiredCardinalities(int index)

Description copied from interface: ExpressionParent

Gets list of all acceptable cardinalities which can child expression at given position produce.

For example delete expression returns single cardinality for index 0 and list of multiple and ordered cardinality for index 1.

Result of this method can change in time.

Static example is expression or. Expression or accepts only single cardinality for any index.

Dynamic example is expression match. Expression match accepts any cardinality of its children, but this cardinality must be same for all its children.

Specified by:

getRequiredCardinalities in interface ExpressionParent

Overrides:

getRequiredCardinalities in class AbstractExpression

Parameters:

index - position of child expression in this parent

Returns:

list of all possible cardinalities which can child expression at given position produce

getRequiredBaseTypes

public BaseType[] getRequiredBaseTypes(int index)

Description copied from interface: ExpressionParent

Gets list of all acceptable baseTypes which can child expression at given position produce.

Result of this method can change in time.

Static example is expression or. Expression or accepts only boolean baseType for any index.

Dynamic example is expression match. Expression match accepts any baseType of its children. but this baseType must be same for all its children.

Specified by:

getRequiredBaseTypes in interface ExpressionParent

Overrides:

getRequiredBaseTypes in class AbstractExpression

Parameters:

index - position of child expression in this parent

Returns:

list of all acceptable baseTypes which can child expression at given position produce

validateChildren

protected ValidationResult validateChildren()

Description copied from class: AbstractNode

Validates children (body) of this node.

Overrides:

validateChildren in class AbstractNode

Returns:

result of validation

evaluateSelf

protected Value evaluateSelf(int depth)

Description copied from class: AbstractExpression

Evaluates this expression. All children must be already evaluated. Contains no checks.

Specified by:

evaluateSelf in class AbstractExpression

Parameters:

depth - depth of this expression in expression tree (root's depth = 0)

Returns:

result of evaluation