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:
- Serializable, SourceLocator, LocationProvider, SaxonLocator, InstructionInfo, Locator
public class NumberFn
- extends SystemFunction
Implements the XPath number() 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, 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, preEvaluate, promote, replaceSubExpression, setArguments, setFunctionName, simplifyArguments, toString |
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, getIntegerBounds, 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 |
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
typeCheck
public Expression typeCheck(ExpressionVisitor visitor,
ExpressionVisitor.ContextItemType contextItemType)
throws XPathException
- 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)
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
- 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,
Configuration config)
- 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 convertedconfig
-
- Returns:
- the result of the conversion
Copyright (c) 2004-2011 Saxonica Limited. All rights reserved.