net.sf.saxon.functions
Class Component

java.lang.Object
  net.sf.saxon.expr.Expression
      net.sf.saxon.expr.FunctionCall
          net.sf.saxon.functions.SystemFunction
              net.sf.saxon.functions.Component

All Implemented Interfaces:

Serializable, SourceLocator, LocationProvider, SaxonLocator, InstructionInfo, Locator

public class Component
extends SystemFunction

This class supports the get_X_from_Y functions defined in XPath 2.0

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Serialized Form

Field Summary

static int	DAY
static int	HOURS
static int	LOCALNAME
static int	MICROSECONDS
static int	MINUTES
static int	MONTH
static int	NAMESPACE
static int	PREFIX
static int	SECONDS
static int	TIMEZONE
static int	WHOLE_SECONDS
static int	YEAR
static int	YEAR_ALLOWING_ZERO

Fields inherited from class net.sf.saxon.functions.SystemFunction

operation

Fields inherited from class net.sf.saxon.expr.FunctionCall

argument

Fields inherited from class net.sf.saxon.expr.Expression

EFFECTIVE_BOOLEAN_VALUE, EVALUATE_METHOD, EVENT_FEED_METHOD, ITEM_FEED_METHOD, ITERATE_METHOD, locationId, MAX_SEQUENCE_LENGTH, MAX_STRING_LENGTH, PROCESS_METHOD, PUSH_SELECTION, staticProperties, UNBOUNDED_LOWER, UNBOUNDED_UPPER, WATCH_METHOD

Constructor Summary

Component()

Method Summary

Expression	copy() Copy an expression.
Item	evaluateItem(XPathContext context) Evaluate the expression
IntegerValue[]	getIntegerBounds() For an expression that returns an integer or a sequence of integers, get a lower and upper bound on the values of the integers that may be returned, from static analysis.
int	getRequiredComponent() Get the required component
String	getRequiredComponentAsString() Get the required component name as a string
Expression	simplify(ExpressionVisitor visitor) Simplify the function call.

Methods inherited from class net.sf.saxon.functions.SystemFunction

addContextDocumentArgument, addDocToPathMap, checkArguments, computeCardinality, computeSpecialProperties, equals, getDetails, getErrorCodeForTypeErrors, getImplementationMethod, getItemType, getOperation, getRequiredType, makeSystemFunction, optimize, setDetails, useContextItemAsDefault

Methods inherited from class net.sf.saxon.expr.FunctionCall

addExternalFunctionCallToPathMap, checkArgumentCount, explain, getArguments, getDisplayName, getExpressionName, getFunctionName, getNumberOfArguments, hashCode, iterateSubExpressions, preEvaluate, promote, replaceSubExpression, setArguments, setFunctionName, simplifyArguments, toString, typeCheck

Methods inherited from class net.sf.saxon.expr.Expression

addToPathMap, adoptChildExpression, checkForUpdatingSubexpressions, checkPermittedContents, computeDependencies, computeStaticProperties, doPromotion, dynamicError, effectiveBooleanValue, evaluateAsString, evaluatePendingUpdates, explain, getCardinality, getColumnNumber, getColumnNumber, getConstructType, getContainer, getDependencies, getEvaluationMethod, getExecutable, getHostLanguage, getIntrinsicDependencies, getLineNumber, getLineNumber, getLocationId, getLocationProvider, getObjectName, getProperties, getProperty, getPublicId, getSlotsUsed, getSpecialProperties, getSystemId, getSystemId, hasLoopingSubexpression, hasVariableBinding, implementsStaticTypeCheck, isSubtreeExpression, isUpdatingExpression, isVacuousExpression, iterate, iterateEvents, iterateSameFocusSubExpressions, markTailFunctionCalls, process, resetLocalStaticProperties, setContainer, setEvaluationMethod, setFiltered, setFlattened, setLocationId, staticTypeCheck, suppressValidation, typeError

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

YEAR

public static final int YEAR

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Constant Field Values

MONTH

public static final int MONTH

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Constant Field Values

DAY

public static final int DAY

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Constant Field Values

HOURS

public static final int HOURS

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Constant Field Values

MINUTES

public static final int MINUTES

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Constant Field Values

SECONDS

public static final int SECONDS

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Constant Field Values

TIMEZONE

public static final int TIMEZONE

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Constant Field Values

LOCALNAME

public static final int LOCALNAME

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Constant Field Values

NAMESPACE

public static final int NAMESPACE

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Constant Field Values

PREFIX

public static final int PREFIX

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Constant Field Values

MICROSECONDS

public static final int MICROSECONDS

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Constant Field Values

WHOLE_SECONDS

public static final int WHOLE_SECONDS

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Constant Field Values

YEAR_ALLOWING_ZERO

public static final int YEAR_ALLOWING_ZERO

See Also:

Constant Field Values

Constructor Detail

Component

public Component()

Method Detail

simplify

public Expression simplify(ExpressionVisitor visitor)
                    throws XPathException

Description copied from class: FunctionCall

Simplify the function call. Default method is to simplify each of the supplied arguments and evaluate the function if all are now known.

Overrides:

simplify in class FunctionCall

Parameters:

visitor - an expression visitor

Returns:

the simplified expression

Throws:

XPathException - if an error is discovered during expression rewriting

getIntegerBounds

public IntegerValue[] getIntegerBounds()

For an expression that returns an integer or a sequence of integers, get a lower and upper bound on the values of the integers that may be returned, from static analysis. The default implementation returns null, meaning "unknown" or "not applicable". Other implementations return an array of two IntegerValue objects, representing the lower and upper bounds respectively. The values UNBOUNDED_LOWER and UNBOUNDED_UPPER are used by convention to indicate that the value may be arbitrarily large. The values MAX_STRING_LENGTH and MAX_SEQUENCE_LENGTH are used to indicate values limited by the size of a string or the size of a sequence.

Overrides:

getIntegerBounds in class Expression

Returns:

the lower and upper bounds of integer values in the result, or null to indicate unknown or not applicable.

getRequiredComponent

public int getRequiredComponent()

Get the required component

getRequiredComponentAsString

public String getRequiredComponentAsString()

Get the required component name as a string

evaluateItem

public Item evaluateItem(XPathContext context)
                  throws XPathException

Evaluate the expression

Overrides:

evaluateItem in class Expression

Parameters:

context - The context in which the expression is to be evaluated

Returns:

the node or atomic value that results from evaluating the expression; or null to indicate that the result is an empty sequence

Throws:

XPathException - if any dynamic error occurs evaluating the expression

copy

public Expression copy()

Copy an expression. This makes a deep copy.

Overrides:

copy in class SystemFunction

Returns:

the copy of the original expression