net.sf.saxon.functions
Class NormalizeSpace
java.lang.Object
net.sf.saxon.expr.Expression
net.sf.saxon.expr.FunctionCall
net.sf.saxon.functions.SystemFunction
net.sf.saxon.functions.NormalizeSpace
- All Implemented Interfaces:
- Serializable, SourceLocator, LocationProvider, SaxonLocator, InstructionInfo, Locator
public class NormalizeSpace
- extends SystemFunction
Implement the XPath normalize-space() function
- See Also:
- Serialized Form
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 |
Methods inherited from class net.sf.saxon.functions.SystemFunction |
addContextDocumentArgument, addDocToPathMap, checkArguments, computeCardinality, computeSpecialProperties, copy, 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, promote, replaceSubExpression, setArguments, setFunctionName, simplify, simplifyArguments, toString |
Methods inherited from class net.sf.saxon.expr.Expression |
addToPathMap, adoptChildExpression, checkForUpdatingSubexpressions, checkPermittedContents, computeDependencies, computeStaticProperties, doPromotion, dynamicError, evaluateAsString, evaluatePendingUpdates, explain, getCardinality, getColumnNumber, getColumnNumber, getConstructType, getContainer, getDependencies, getEvaluationMethod, getExecutable, getHostLanguage, getIntegerBounds, 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 |
NormalizeSpace
public NormalizeSpace()
getIntrinsicDependencies
public int getIntrinsicDependencies()
- Determine the intrinsic dependencies of an expression, that is, those which are not derived
from the dependencies of its subexpressions. For example, position() has an intrinsic dependency
on the context position, while (position()+1) does not. The default implementation
of the method returns 0, indicating "no dependencies".
- Overrides:
getIntrinsicDependencies
in class Expression
- Returns:
- a set of bit-significant flags identifying the "intrinsic"
dependencies. The flags are documented in class net.sf.saxon.value.StaticProperty
typeCheck
public Expression typeCheck(ExpressionVisitor visitor,
ExpressionVisitor.ContextItemType contextItemType)
throws XPathException
- Description copied from class:
FunctionCall
- Type-check the expression. This also calls preEvaluate() to evaluate the function
if all the arguments are constant; functions that do not require this behavior
can override the preEvaluate method.
- Overrides:
typeCheck
in class FunctionCall
- Parameters:
visitor
- an expression visitorcontextItemType
- the static type of "." at the point where this expression is invoked.
The parameter is set to null if it is known statically that the context item will be undefined.
If the type of the context item is not known statically, the argument is set to
Type.ITEM_TYPE
- Returns:
- the original expression, rewritten to perform necessary run-time type checks,
and to perform other type-related optimizations
- Throws:
XPathException
- if an error is discovered during this phase
(typically a type error)
preEvaluate
public Expression preEvaluate(ExpressionVisitor visitor)
throws XPathException
- Pre-evaluate a function at compile time. Functions that do not allow
pre-evaluation, or that need access to context information, can override this method.
- Overrides:
preEvaluate
in class FunctionCall
- Parameters:
visitor
- an expression visitor
- Returns:
- the result of the early evaluation, or the original expression, or potentially
a simplified expression
- Throws:
XPathException
- if evaluation fails
evaluateItem
public Item evaluateItem(XPathContext c)
throws XPathException
- Evaluate in a general context
- Overrides:
evaluateItem
in class Expression
- Parameters:
c
- 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
effectiveBooleanValue
public boolean effectiveBooleanValue(XPathContext c)
throws XPathException
- Get the effective boolean value of the expression. This returns false if the value
is the empty sequence, a zero-length string, a number equal to zero, or the boolean
false. Otherwise it returns true.
This method is implemented for normalize-space() because it is quite often used in a
boolean context to test whether a value exists and is non-white, and because testing for the
presence of non-white characters is a lot more efficient than constructing the normalized
string, especially because of early-exit.
- Overrides:
effectiveBooleanValue
in class Expression
- Parameters:
c
- The context in which the expression is to be evaluated
- Returns:
- the effective boolean value
- Throws:
XPathException
- if any dynamic error occurs evaluating the expression
Copyright (c) 2004-2011 Saxonica Limited. All rights reserved.