Package net.sf.saxon.functions
Class NumberFn
- java.lang.Object
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- net.sf.saxon.expr.Expression
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- net.sf.saxon.expr.FunctionCall
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- net.sf.saxon.functions.SystemFunction
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- net.sf.saxon.functions.NumberFn
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- 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
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Field Summary
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Fields inherited from class net.sf.saxon.functions.SystemFunction
operation
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Fields inherited from class net.sf.saxon.expr.FunctionCall
argument
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Fields inherited from class net.sf.saxon.expr.Expression
EVALUATE_METHOD, ITERATE_METHOD, locationId, PROCESS_METHOD, staticProperties
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Constructor Summary
Constructors Constructor Description NumberFn()
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Method Summary
All Methods Static Methods Instance Methods Concrete Methods Modifier and Type Method Description PathMap.PathMapNodeSet
addDocToPathMap(PathMap pathMap, PathMap.PathMapNodeSet pathMapNodes)
Add a representation of a doc() call or similar function to a PathMap.static DoubleValue
convert(AtomicValue value)
Static method to perform the same conversion as the number() function.Item
evaluateItem(XPathContext context)
Evaluate in a general contextItem
map(Item item)
Mapping function for use when converting a sequence of atomic values to doubles using the rules of the number() functionExpression
simplify(ExpressionVisitor visitor)
Simplify and validate.-
Methods inherited from class net.sf.saxon.functions.SystemFunction
addContextDocumentArgument, checkArguments, computeCardinality, computeSpecialProperties, copy, getDetails, getErrorCodeForTypeErrors, getItemType, getRequiredType, makeSystemFunction, optimize, setDetails, useContextItemAsDefault
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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
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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
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Method Detail
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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 classFunctionCall
- Parameters:
visitor
- an expression visitor- Returns:
- the simplified expression
- Throws:
XPathException
- if an error is discovered during expression rewriting
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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 classSystemFunction
- 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
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evaluateItem
public Item evaluateItem(XPathContext context) throws XPathException
Evaluate in a general context- Specified by:
evaluateItem
in interfaceEvaluableItem
- Overrides:
evaluateItem
in classExpression
- 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
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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
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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 interfaceItemMappingFunction
- Parameters:
item
- The input item to be mapped.- Returns:
- either the output item, or null.
- Throws:
XPathException
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