Class BooleanFn
- All Implemented Interfaces:
Callable
,FunctionItem
,GroundedValue
,Item
,Sequence
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Nested Class Summary
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Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptioncall
(XPathContext c, Sequence[] arguments) Call the Callable.Make an elaborator for this expressionGet 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.makeFunctionCall
(Expression[] arguments) Make an expression that either calls this function, or that is equivalent to a call on this functionstatic Expression
rewriteEffectiveBooleanValue
(Expression exp, ExpressionVisitor visitor, ContextItemStaticInfo contextItemType) Optimize an expression whose effective boolean value is required.void
supplyTypeInformation
(ExpressionVisitor visitor, ContextItemStaticInfo contextItemType, Expression[] arguments) Method called during static type checking.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, getUniStringArg, hashCode, importAttributes, isSequenceVariadic, isTrustedResultType, makeCall, makeFunction, makeFunction40, makeOptimizedFunctionCall, resultIfEmpty, setArity, setDetails, setRetainedStaticContext, 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
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Constructor Details
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BooleanFn
public BooleanFn()
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Method Details
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supplyTypeInformation
public void supplyTypeInformation(ExpressionVisitor visitor, ContextItemStaticInfo contextItemType, Expression[] arguments) throws XPathException Description copied from class:SystemFunction
Method called during static type checking. This method may be implemented in subclasses so that functions can take advantage of knowledge of the types of the arguments that will be supplied.- Overrides:
supplyTypeInformation
in classSystemFunction
- Parameters:
visitor
- an expression visitor, providing access to the static context and configurationcontextItemType
- information about whether the context item is set, and what its type isarguments
- the expressions appearing as arguments in the function call- Throws:
XPathException
- if an error is detected
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rewriteEffectiveBooleanValue
public static Expression rewriteEffectiveBooleanValue(Expression exp, ExpressionVisitor visitor, ContextItemStaticInfo contextItemType) throws XPathException Optimize an expression whose effective boolean value is required. It is appropriate to apply this rewrite to any expression whose value will be obtained by calling the Expression.effectiveBooleanValue() method (and not otherwise)- Parameters:
exp
- the expression whose EBV is to be evaluatedvisitor
- an expression visitorcontextItemType
- the type of the context item for this expression- Returns:
- an expression that returns the EBV of exp, or null if no optimization was possible
- Throws:
XPathException
- if static errors are found
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call
Description copied from interface:Callable
Call the Callable.- Parameters:
c
- the dynamic evaluation contextarguments
- 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 method 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
orAtomicValue
.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 evaluation, in the form of a Sequence. It is the responsibility of the callee to ensure that the type of result conforms to the expected result type.
- Throws:
XPathException
- if a dynamic error occurs during the evaluation of the expression
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makeFunctionCall
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 classSystemFunction
- 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
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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 classSystemFunction
- 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.
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getElaborator
Make an elaborator for this expression- Overrides:
getElaborator
in classSystemFunction
- Returns:
- a suitable elaborator
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