net.sf.saxon.functions
Class FormatNumber

java.lang.Object
  extended by net.sf.saxon.expr.Expression
      extended by net.sf.saxon.expr.FunctionCall
          extended by net.sf.saxon.functions.SystemFunction
              extended by net.sf.saxon.functions.FormatNumber
All Implemented Interfaces:
Serializable, SourceLocator, LocationProvider, SaxonLocator, CallableExpression, InstructionInfo, Locator

public class FormatNumber
extends SystemFunction
implements CallableExpression

XSLT 2.0 implementation of format-number() function - removes the dependence on the JDK.

See Also:
Serialized Form

Field Summary
 
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
FormatNumber()
           
 
Method Summary
static BigDecimal adjustToDecimal(double value, int precision)
          Convert a double to a BigDecimal.
 SequenceIterator call(SequenceIterator[] arguments, XPathContext context)
          Evaluate the expression
 void checkArguments(ExpressionVisitor visitor)
          Method called during static type checking
 Expression copy()
          Copy an expression.
 boolean equals(Object o)
          Determine whether two expressions are equivalent
 CharSequence evaluateAsString(XPathContext context)
          Evaluate in a context where a string is wanted
 Item evaluateItem(XPathContext c)
          Evaluate in a general context
 Expression preEvaluate(ExpressionVisitor visitor)
          preEvaluate: this method suppresses compile-time evaluation by doing nothing.
 void setNamespaceResolver(SavedNamespaceContext savedNamespaceContext)
           
 
Methods inherited from class net.sf.saxon.functions.SystemFunction
addContextDocumentArgument, addDocToPathMap, computeCardinality, computeSpecialProperties, 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, typeCheck
 
Methods inherited from class net.sf.saxon.expr.Expression
addToPathMap, adoptChildExpression, checkForUpdatingSubexpressions, checkPermittedContents, computeDependencies, computeStaticProperties, doPromotion, dynamicError, effectiveBooleanValue, 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
 
Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
 
Methods inherited from interface net.sf.saxon.expr.CallableExpression
getArguments
 

Constructor Detail

FormatNumber

public FormatNumber()
Method Detail

setNamespaceResolver

public void setNamespaceResolver(SavedNamespaceContext savedNamespaceContext)

checkArguments

public void checkArguments(ExpressionVisitor visitor)
                    throws XPathException
Description copied from class: SystemFunction
Method called during static type checking

Overrides:
checkArguments in class SystemFunction
Parameters:
visitor - the expression visitor
Throws:
XPathException - if the arguments are incorrect

preEvaluate

public Expression preEvaluate(ExpressionVisitor visitor)
                       throws XPathException
preEvaluate: this method suppresses compile-time evaluation by doing nothing. We can't evaluate early because we don't have access to the DecimalFormatManager.

Overrides:
preEvaluate in class FunctionCall
Parameters:
visitor - the expression visitor
Returns:
the result of the early evaluation, or the original expression, or potentially a simplified expression
Throws:
XPathException - if evaluation fails

copy

public Expression copy()
Copy an expression. This makes a deep copy.

Overrides:
copy in class SystemFunction
Returns:
the copy of the original expression

equals

public boolean equals(Object o)
Determine whether two expressions are equivalent

Overrides:
equals in class SystemFunction

evaluateAsString

public CharSequence evaluateAsString(XPathContext context)
                              throws XPathException
Evaluate in a context where a string is wanted

Overrides:
evaluateAsString in class Expression
Parameters:
context - The context in which the expression is to be evaluated
Returns:
the value of the expression, evaluated in the current context. The expression must return a string or (); if the value of the expression is (), this method returns "".
Throws:
XPathException - if any dynamic error occurs evaluating the expression

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

adjustToDecimal

public static BigDecimal adjustToDecimal(double value,
                                         int precision)
Convert a double to a BigDecimal. In general there will be several BigDecimal values that are equal to the supplied value, and the one we want to choose is the one with fewest non-zero digits. The algorithm used is rather pragmatic: look for a string of zeroes or nines, try rounding the number down or up as approriate, then convert the adjusted value to a double to see if it's equal to the original: if not, use the original value unchanged.

Parameters:
value - the double to be converted
precision - 2 for a double, 1 for a float
Returns:
the result of conversion to a double

call

public SequenceIterator call(SequenceIterator[] arguments,
                             XPathContext context)
                      throws XPathException
Description copied from interface: CallableExpression
Evaluate the expression

Specified by:
call in interface CallableExpression
Parameters:
arguments - the values of the arguments, supplied as SequenceIterators
context - the dynamic evaluation context
Returns:
the result of the evaluation, in the form of a SequenceIterator
Throws:
XPathException - if a dynamic error occurs during the evaluation of the expression


Copyright (c) 2004-2011 Saxonica Limited. All rights reserved.