Package net.sf.saxon.functions
Class Concat
java.lang.Object
net.sf.saxon.functions.AbstractFunction
net.sf.saxon.functions.SystemFunction
net.sf.saxon.functions.Concat
- All Implemented Interfaces:
Callable
,PushableFunction
,Function
,GroundedValue
,Item
,Sequence
Implementation of the fn:concat() function
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Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptioncall
(XPathContext context, Sequence[] arguments) Invoke the functionGet the (local) name of a class that can be used to generate bytecode for this system functionGet the item type of the function itemGet the roles of the arguments, for the purposes of streaminggetRequiredType
(int arg) Get the required type of the nth argumentmakeOptimizedFunctionCall
(ExpressionVisitor visitor, ContextItemStaticInfo contextInfo, Expression... arguments) Allow the function to create an optimized call based on the values of the actual argumentsvoid
process
(Outputter destination, XPathContext context, Sequence[] arguments) Evaluate the function in "push" modeprotected Sequence
resultIfEmpty
(int arg) Ask if the function always returns a known result when one of the arguments is an empty sequenceMethods inherited from class net.sf.saxon.functions.SystemFunction
dependsOnContextItem, dynamicCall, equals, export, exportAdditionalArguments, exportAttributes, fixArguments, getArity, getCardinality, getContextNode, getDescription, getDetails, getErrorCodeForTypeErrors, getFunctionName, getIntegerBounds, getNetCost, getResultItemType, getResultItemType, getRetainedStaticContext, getSpecialProperties, getStaticBaseUriString, getStreamerName, importAttributes, isTrustedResultType, makeCall, makeFunction, makeFunctionCall, setArity, setDetails, setRetainedStaticContext, supplyTypeInformation, toShortString, toString, typeCheckCaller
Methods inherited from class net.sf.saxon.functions.AbstractFunction
atomize, deepEquals, effectiveBooleanValue, getAnnotations, getStringValue, getStringValueCS, isArray, isMap, makeNewContext, simplify, typeCheck
Methods inherited from class java.lang.Object
clone, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
Methods inherited from interface net.sf.saxon.om.GroundedValue
asIterable, concatenate, containsNode, materialize
Methods inherited from interface net.sf.saxon.om.Item
getLength, head, isStreamed, itemAt, iterate, reduce, subsequence
Methods inherited from interface net.sf.saxon.om.Sequence
makeRepeatable
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Constructor Details
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Concat
public Concat()
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Method Details
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resultIfEmpty
Description copied from class:SystemFunction
Ask if the function always returns a known result when one of the arguments is an empty sequence- Overrides:
resultIfEmpty
in classSystemFunction
- Parameters:
arg
- the argument whose value is an empty sequence (counting from zero)- Returns:
- the value to be returned when this argument is an empty sequence, or null if unknown / not applicable
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getOperandRoles
Get the roles of the arguments, for the purposes of streaming- Specified by:
getOperandRoles
in interfaceFunction
- Overrides:
getOperandRoles
in classSystemFunction
- Returns:
- an array of OperandRole objects, one for each argument
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getFunctionItemType
Get the item type of the function item- Specified by:
getFunctionItemType
in interfaceFunction
- Overrides:
getFunctionItemType
in classSystemFunction
- Returns:
- the function item's type
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makeOptimizedFunctionCall
public Expression makeOptimizedFunctionCall(ExpressionVisitor visitor, ContextItemStaticInfo contextInfo, Expression... arguments) throws XPathException Allow the function to create an optimized call based on the values of the actual arguments- Overrides:
makeOptimizedFunctionCall
in classSystemFunction
- Parameters:
visitor
- the expression visitorcontextInfo
- information about the context itemarguments
- the supplied arguments to the function call. Note: modifying the contents of this array should not be attempted, it is likely to have no effect.- Returns:
- either a function call on this function, or an expression that delivers the same result, or null indicating that no optimization has taken place
- Throws:
XPathException
- if an error is detected
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call
Description copied from interface:Function
Invoke the function- Specified by:
call
in interfaceCallable
- Specified by:
call
in interfaceFunction
- Parameters:
context
- the XPath dynamic evaluation contextarguments
- the actual arguments to be supplied- Returns:
- the result of invoking the function
- Throws:
XPathException
- if a dynamic error occurs within the function
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process
public void process(Outputter destination, XPathContext context, Sequence[] arguments) throws XPathException Description copied from interface:PushableFunction
Evaluate the function in "push" mode- Specified by:
process
in interfacePushableFunction
- Parameters:
destination
- the destination for the function resultcontext
- the dynamic evaluation contextarguments
- the supplied arguments to the function- Throws:
XPathException
- if a dynamic error occurs during the evaluation
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getRequiredType
Get the required type of the nth argument- Overrides:
getRequiredType
in classSystemFunction
- Parameters:
arg
- the number of the argument whose type is requested, zero-based- Returns:
- the required type of the argument as defined in the function signature
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getCompilerName
Description copied from class:SystemFunction
Get the (local) name of a class that can be used to generate bytecode for this system function- Overrides:
getCompilerName
in classSystemFunction
- Returns:
- the name of a bytecode generation class, or null if there is no bytecode support for this function
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