Package net.sf.saxon.functions

Class Sum

java.lang.Object

net.sf.saxon.functions.AbstractFunction

net.sf.saxon.functions.SystemFunction

net.sf.saxon.functions.FoldingFunction

net.sf.saxon.functions.Sum

All Implemented Interfaces:

Callable, FunctionItem, GroundedValue, Item, Sequence

public class Sum
extends FoldingFunction

Implementation of the fn:sum function

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	Sum.SumFnElaborator
static class	Sum.SumFold	Implementation of Fold class to do the summation in push mode

Constructor Summary

Constructors

Constructor	Description
Sum()

Method Summary

Modifier and Type	Method	Description
int	getCardinality(Expression[] arguments)	Get the cardinality, given knowledge of the actual arguments
Elaborator	getElaborator()	Make an elaborator for a system function call on this function
Fold	getFold(XPathContext context, Sequence... additionalArguments)	Create the Fold object which actually performs the evaluation.
ItemType	getResultItemType(Expression[] args)	Get the return type, given knowledge of the actual arguments
Expression	makeFunctionCall(Expression... arguments)	Make an expression that either calls this function, or that is equivalent to a call on this function
static AtomicValue	total(SequenceIterator in, XPathContext context, Location locator)	Static method to compute a total, invoked from compiled bytecode

Methods inherited from class net.sf.saxon.functions.FoldingFunction

call, getStreamerName

Methods inherited from class net.sf.saxon.functions.SystemFunction

dependsOnContextItem, dynamicCall, equals, export, exportAdditionalArguments, exportAttributes, fixArguments, getArity, getContextNode, getDescription, getDetails, getErrorCodeForTypeErrors, getFunctionItemType, getFunctionName, getIntegerBounds, getNetCost, getOperandRoles, getRequiredType, getResultItemType, getRetainedStaticContext, getSpecialProperties, getStaticBaseUriString, getUniStringArg, hashCode, importAttributes, isSequenceVariadic, isTrustedResultType, makeCall, makeFunction, makeFunction40, makeOptimizedFunctionCall, resultIfEmpty, setArity, setDetails, setRetainedStaticContext, supplyTypeInformation, toShortString, toString, typeCheckCaller

Methods inherited from class net.sf.saxon.functions.AbstractFunction

atomize, deepEqual40, deepEquals, effectiveBooleanValue, getAnnotations, getUnicodeStringValue, isArray, isMap, makeNewContext, simplify, typeCheck

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface net.sf.saxon.om.FunctionItem

getGenre

Methods inherited from interface net.sf.saxon.om.GroundedValue

asIterable, concatenate, containsNode, materialize

Methods inherited from interface net.sf.saxon.om.Item

getLength, getStringValue, head, isStreamed, itemAt, iterate, reduce, subsequence

Methods inherited from interface net.sf.saxon.om.Sequence

makeRepeatable

Constructor Detail

Sum

public Sum()

Method Detail

makeFunctionCall

public Expression makeFunctionCall(Expression... arguments)

Description copied from class: SystemFunction

Make an expression that either calls this function, or that is equivalent to a call on this function

Overrides:

makeFunctionCall in class SystemFunction

Parameters:

arguments - the supplied arguments to the function call

Returns:

either a function call on this function, or an expression that delivers the same result

getResultItemType

public ItemType getResultItemType(Expression[] args)

Description copied from class: SystemFunction

Get the return type, given knowledge of the actual arguments

Overrides:

getResultItemType in class SystemFunction

Parameters:

args - the actual arguments supplied

Returns:

the best available item type that the function will return

getCardinality

public int getCardinality(Expression[] arguments)

Description copied from class: SystemFunction

Get the cardinality, given knowledge of the actual arguments

Overrides:

getCardinality in class SystemFunction

Parameters:

arguments - the actual arguments supplied

Returns:

the most precise available cardinality that the function will return

getFold

public Fold getFold(XPathContext context,
                    Sequence... additionalArguments)
             throws XPathException

Create the Fold object which actually performs the evaluation.

Specified by:

getFold in class FoldingFunction

Parameters:

context - the dynamic evaluation context

additionalArguments - the values of all arguments other than the first.

Returns:

the Fold object used to compute the function

Throws:

XPathException - if a dynamic error occurs

total

public static AtomicValue total(SequenceIterator in,
                                XPathContext context,
                                Location locator)
                         throws XPathException

Static method to compute a total, invoked from compiled bytecode

Parameters:

in - the sequence of items to be summed

context - dynamic context for evaluation

locator - expression location for diagnostics

Returns:

null if the input is empty, otherwise the total as defined by the semantics of the sum() function

Throws:

XPathException - if a dynamic error occurs

getElaborator

public Elaborator getElaborator()

Make an elaborator for a system function call on this function

Overrides:

getElaborator in class SystemFunction

Returns:

a suitable elaborator; or null if no custom elaborator is available