Package net.sf.saxon.functions

Class Subsequence_2

java.lang.Object

net.sf.saxon.functions.AbstractFunction

net.sf.saxon.functions.SystemFunction

net.sf.saxon.functions.Subsequence_2

All Implemented Interfaces:

Callable, FunctionItem, GroundedValue, Item, Sequence

public class Subsequence_2
extends SystemFunction
implements Callable

Implements the XPath 2.0 subsequence() function with two arguments

Constructor Summary

Constructors

Constructor	Description
Subsequence_2()

Method Summary

Modifier and Type	Method	Description
Sequence	call(XPathContext context, Sequence[] arguments)	Call the function
int	getCardinality(Expression[] arguments)	Determine the cardinality of the function.
int	getSpecialProperties(Expression[] arguments)	Get the static properties of this expression (other than its type).
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.
Expression	makeFunctionCall(Expression[] arguments)	Make an expression that either calls this function, or that is equivalent to a call on this function
static SequenceIterator	subSequence(SequenceIterator seq, NumericValue startVal)

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

dependsOnContextItem, dynamicCall, equals, export, exportAdditionalArguments, exportAttributes, fixArguments, getArity, getContextNode, getDescription, getDetails, getElaborator, getErrorCodeForTypeErrors, getFunctionItemType, getFunctionName, getIntegerBounds, getNetCost, getOperandRoles, getRequiredType, getResultItemType, getResultItemType, getRetainedStaticContext, 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 Details

Subsequence_2

public Subsequence_2()

Method Details

getSpecialProperties

public int getSpecialProperties(Expression[] arguments)

Get the static properties of this expression (other than its type). The result is bit-significant. These properties are used for optimizations. In general, if property bit is set, it is true, but if it is unset, the value is unknown.

Overrides:

getSpecialProperties in class SystemFunction

Parameters:

arguments - the actual arguments to the function call

Returns:

the properties

getCardinality

public int getCardinality(Expression[] arguments)

Determine the cardinality of the function.

Overrides:

getCardinality in class SystemFunction

Parameters:

arguments - the actual arguments supplied

Returns:

the most precise available cardinality that the function will return

call

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

Call the function

Specified by:

call in interface Callable

Parameters:

context - the dynamic evaluation context

arguments - the values of the arguments, supplied as Sequences.

Generally it is advisable, if calling iterate() to process a supplied sequence, to call it only once; if the value is required more than once, it should first be converted to a GroundedValue by calling the utility methd SequenceTool.toGroundedValue().

If the expected value is a single item, the item should be obtained by calling Sequence.head(): it cannot be assumed that the item will be passed as an instance of Item or AtomicValue.

It is the caller's responsibility to perform any type conversions required to convert arguments to the type expected by the callee. An exception is where this Callable is explicitly an argument-converting wrapper around the original Callable.

Returns:

the result of the function call

Throws:

XPathException - if a dynamic error occurs

subSequence

public static SequenceIterator subSequence(SequenceIterator seq,
 NumericValue startVal)
                                    throws XPathException

Throws:

XPathException

makeFunctionCall

public Expression makeFunctionCall(Expression[] arguments)

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

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.