net.sf.saxon.functions
Class NumberFn
java.lang.Object
net.sf.saxon.expr.Expression
net.sf.saxon.expr.FunctionCall
net.sf.saxon.functions.SystemFunction
net.sf.saxon.functions.NumberFn
- All Implemented Interfaces:
- java.io.Serializable, javax.xml.transform.SourceLocator, LocationProvider, SaxonLocator, EvaluableItem, ItemMappingFunction, SequenceIterable, InstructionInfo, org.xml.sax.Locator
public class NumberFn
- extends SystemFunction
- implements ItemMappingFunction
Implements the XPath number() function. This can also be used as a mapping function
in a MappingIterator to map a sequence of values to numbers.
- See Also:
- Serialized Form
Methods inherited from class net.sf.saxon.functions.SystemFunction |
addContextDocumentArgument, checkArguments, computeCardinality, computeSpecialProperties, copy, getDetails, getErrorCodeForTypeErrors, getItemType, getRequiredType, makeSystemFunction, optimize, setDetails, useContextItemAsDefault |
Methods inherited from class net.sf.saxon.expr.FunctionCall |
addExternalFunctionCallToPathMap, checkArgumentCount, equals, explain, getArguments, getDisplayName, 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, display, doPromotion, dynamicError, effectiveBooleanValue, evaluateAsString, evaluatePendingUpdates, explain, findParentOf, getCardinality, getColumnNumber, getColumnNumber, getConstructType, getContainer, getDependencies, getExecutable, getHostLanguage, getImplementationMethod, getIntrinsicDependencies, getLineNumber, getLineNumber, getLocationId, getLocationProvider, getObjectName, getProperties, getProperty, getPublicId, getSlotsUsed, getSpecialProperties, getSystemId, getSystemId, hasLoopingSubexpression, implementsStaticTypeCheck, isUpdatingExpression, iterate, iterateEvents, markTailFunctionCalls, process, resetLocalStaticProperties, setContainer, setFiltered, setFlattened, setLocationId, staticTypeCheck, suppressValidation, typeError |
Methods inherited from class java.lang.Object |
clone, finalize, getClass, notify, notifyAll, wait, wait, wait |
NumberFn
public NumberFn()
simplify
public Expression simplify(ExpressionVisitor visitor)
throws XPathException
- Simplify and validate.
This is a pure function so it can be simplified in advance if the arguments are 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
addDocToPathMap
public PathMap.PathMapNodeSet addDocToPathMap(PathMap pathMap,
PathMap.PathMapNodeSet pathMapNodes)
- Add a representation of a doc() call or similar function to a PathMap.
This is a convenience method called by the addToPathMap() methods for doc(), document(), collection()
and similar functions. These all create a new root expression in the path map.
- Overrides:
addDocToPathMap
in class SystemFunction
- Parameters:
pathMap
- the PathMap to which the expression should be addedpathMapNodes
- the node in the PathMap representing the focus at the point where this expression
is called. Set to null if this expression appears at the top level.
- Returns:
- the pathMapNode representing the focus established by this expression, in the case where this
expression is the first operand of a path expression or filter expression
evaluateItem
public Item evaluateItem(XPathContext context)
throws XPathException
- Evaluate in a general context
- Specified by:
evaluateItem
in interface EvaluableItem
- 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
convert
public static DoubleValue convert(AtomicValue value)
- Static method to perform the same conversion as the number() function. This is different from the
convert(Type.DOUBLE) in that it produces NaN rather than an error for non-numeric operands.
- Parameters:
value
- the value to be converted
- Returns:
- the result of the conversion
map
public Item map(Item item)
throws XPathException
- Mapping function for use when converting a sequence of atomic values to doubles
using the rules of the number() function
- Specified by:
map
in interface ItemMappingFunction
- Parameters:
item
- The input item to be mapped.
- Returns:
- either the output item, or null.
- Throws:
XPathException
Copyright (c) Saxonica Limited. All rights reserved.