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

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.Sum

All Implemented Interfaces:

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

public class Sum
extends AbstractExpression

The sum operator takes one or more sub-expressions which have single or multiple or ordered cardinality (it is possible to mix different cardinalities) and have numerical base-types.

The result is A single float or, if all sub-expressions are of integer type, A single integer that corresponds to the sum of the numerical values of the sub-expressions.

If any of the sub-expressions are NULL then the operator results in NULL.

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

Sum(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[]	getProducedBaseTypes() Gets list of all possible produced baseTypes after evaluation (possible baseTypes of evaluated result).

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

evaluate, getBaseType, getCardinality, getChildren, getFirstChild, getParent, getParentRequiredBaseTypes, getParentRequiredCardinalities, getProducedCardinalities, getProducedNumericalBaseTypes, getRequiredBaseTypes, getRequiredCardinalities, 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, validateChildren

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

Sum

public Sum(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

getProducedBaseTypes

public BaseType[] getProducedBaseTypes()

Description copied from interface: Expression

Gets list of all possible produced baseTypes after evaluation (possible baseTypes of evaluated result). Result of this method can change in time.

Static example is expression or. Expression or can produce only boolean baseType and it cannot change.

Dynamic example is expression variable. Expression variable can produce any baseType before evaluation. After evaluation it produces baseType of its result (and it can change every evaluation call!).

Null expression, empty containers (multiple, ordered, record), or NULL values produces all baseTypes. So they are compatible with anything.

Specified by:

getProducedBaseTypes in interface Expression

Overrides:

getProducedBaseTypes in class AbstractExpression

Returns:

list of all possible produced baseTypes after evaluation

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