Package net.sf.saxon.functions

Class Count

java.lang.Object

net.sf.saxon.functions.AbstractFunction

net.sf.saxon.functions.SystemFunction

net.sf.saxon.functions.Count

All Implemented Interfaces:

Callable, ArityOneFunction, IFunctionWithRetainedParameterNames, FunctionItem, GroundedValue, Item, Sequence

public class Count
extends SystemFunction
implements ArityOneFunction

Implementation of the fn:count function

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	Count.CountFnElaborator

Constructor Summary

Constructors

Constructor	Description
Count()

Method Summary

Modifier and Type	Method	Description
IntegerValue	call(XPathContext context, Sequence[] arguments)	Evaluate the expression
IntegerValue	call1(XPathContext context, Sequence arg0)	Call a function with one argument
static int	count(SequenceIterator iter)	Get the number of items in a sequence identified by a SequenceIterator
Elaborator	getElaborator()	Make an elaborator for this expression
String	getStreamerName()	Get a name that identifies the class that can be used to evaluate this function in streaming mode, that is, supplying one item or event at a time as it is delivered by the parser.
static int	steppingCount(SequenceIterator iter)	Get the number of items in a sequence identified by a SequenceIterator

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

dependsOnContextItem, dynamicCall, equals, export, exportAdditionalArguments, exportAttributes, fixArguments, getArity, getCardinality, getContextNode, getDescription, getDetails, getErrorCodeForTypeErrors, getFunctionItemType, getFunctionName, getNetCost, getOperandRoles, getParameterNames, getRequiredType, getResultItemType, getResultItemType, getRetainedStaticContext, getSpecialProperties, getStaticBaseUriString, getUniqueIdentifier, getUniStringArg, hashCode, importAttributes, isSequenceVariadic, isTrustedResultType, makeCall, makeFunction, makeFunction40, makeFunctionCall, makeOptimizedFunctionCall, makeTrueFunctionCall, 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

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

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

makeRepeatable

Constructor Details

Count

public Count()

Method Details

count

public static int count(SequenceIterator iter)
                 throws XPathException

Get the number of items in a sequence identified by a SequenceIterator

Parameters:

iter - The SequenceIterator. This method moves the current position of the supplied iterator; if this isn't safe, make a copy of the iterator first by calling getAnother(). The supplied iterator must be positioned before the first item (there must have been no call on next()).

Returns:

the number of items in the underlying sequence

Throws:

XPathException - if a failure occurs reading the input sequence

steppingCount

public static int steppingCount(SequenceIterator iter)

Get the number of items in a sequence identified by a SequenceIterator

Parameters:

iter - The SequenceIterator. The supplied iterator must be positioned before the first item (there must have been no call on next()). It will always be consumed

Returns:

the number of items in the underlying sequence

Throws:

UncheckedXPathException - if a failure occurs reading the input sequence

call

public IntegerValue call(XPathContext context,
 Sequence[] arguments)
                  throws XPathException

Evaluate the expression

Specified by:

call in interface Callable

Parameters:

context - the dynamic evaluation context

arguments - the values of the arguments, supplied as Sequences

Returns:

the result of the evaluation, in the form of a Sequence

Throws:

XPathException - if a dynamic error occurs during the evaluation of the expression

call1

public IntegerValue call1(XPathContext context,
 Sequence arg0)
                   throws XPathException

Call a function with one argument

Specified by:

call1 in interface ArityOneFunction

Parameters:

context - the dynamic evaluation context

arg0 - the first argument

Returns:

the result of the function call

Throws:

XPathException - if the call fails with a dynamic error

getStreamerName

public String getStreamerName()

Description copied from class: SystemFunction

Get a name that identifies the class that can be used to evaluate this function in streaming mode, that is, supplying one item or event at a time as it is delivered by the parser. Special streaming support is generally available in Saxon-EE for all system functions that take a sequence as their argument.

Overrides:

getStreamerName in class SystemFunction

Returns:

a name that identifies a class that supports streamed evaluation of this system function, or null if no such class is available. The mapping of names to classes is defined in the Saxon-EE class StreamerMap. In non-streaming Saxon editions (HE and PE) the method always returns null.

getElaborator

public Elaborator getElaborator()

Make an elaborator for this expression

Overrides:

getElaborator in class SystemFunction

Returns:

a suitable elaborator