Package net.sf.saxon.functions
Class Substring
java.lang.Object
net.sf.saxon.functions.AbstractFunction
net.sf.saxon.functions.SystemFunction
net.sf.saxon.functions.Substring
- All Implemented Interfaces:
Callable
,FunctionItem
,GroundedValue
,Item
,Sequence
This class implements the XPath substring() function
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Nested Class Summary
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Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptioncall
(XPathContext context, Sequence[] arguments) Evaluate the expressionMake an elaborator for a system function call on this functionstatic StringValue
substring
(StringValue sv, NumericValue start) Implement the substring function with two arguments.static StringValue
substring
(StringValue sv, NumericValue start, NumericValue len) Implement the substring function with three arguments.typeCheckCaller
(FunctionCall caller, ExpressionVisitor visitor, ContextItemStaticInfo contextInfo) Type-check the expression.Methods inherited from class net.sf.saxon.functions.SystemFunction
dependsOnContextItem, dynamicCall, equals, export, exportAdditionalArguments, exportAttributes, fixArguments, getArity, getCardinality, getContextNode, getDescription, getDetails, getErrorCodeForTypeErrors, getFunctionItemType, getFunctionName, getIntegerBounds, getNetCost, getOperandRoles, getRequiredType, getResultItemType, getResultItemType, getRetainedStaticContext, getSpecialProperties, getStaticBaseUriString, getStreamerName, getUniStringArg, hashCode, importAttributes, isSequenceVariadic, isTrustedResultType, makeCall, makeFunction, makeFunction40, makeFunctionCall, makeOptimizedFunctionCall, resultIfEmpty, setArity, setDetails, setRetainedStaticContext, supplyTypeInformation, toShortString, toString
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
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Constructor Details
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Substring
public Substring()
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Method Details
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typeCheckCaller
public Expression typeCheckCaller(FunctionCall caller, ExpressionVisitor visitor, ContextItemStaticInfo contextInfo) throws XPathException Type-check the expression. This also calls preEvaluate() to evaluate the function if all the arguments are constant; functions that do not require this behavior can override the preEvaluate method.- Overrides:
typeCheckCaller
in classSystemFunction
- Parameters:
caller
- the function call expression calling this functionvisitor
- the expression visitorcontextInfo
- static context information relating to the call- Returns:
- a type-checked replacement for the supplied function call
- Throws:
XPathException
- if an error is detected
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substring
Implement the substring function with two arguments.- Parameters:
sv
- the string valuestart
- the numeric offset (1-based) of the first character to be included in the result (if not an integer, the XPath rules apply)- Returns:
- the substring starting at this position.
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substring
Implement the substring function with three arguments.- Parameters:
sv
- the string valuestart
- the numeric offset (1-based) of the first character to be included in the result (if not an integer, the XPath rules apply)len
- the length of the required substring (again, XPath rules apply)- Returns:
- the substring starting at this position.
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call
Evaluate the expression- Specified by:
call
in interfaceCallable
- Parameters:
context
- the dynamic evaluation contextarguments
- 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
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getElaborator
Make an elaborator for a system function call on this function- Overrides:
getElaborator
in classSystemFunction
- Returns:
- a suitable elaborator; or null if no custom elaborator is available
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